SCN9A ANTISENSE PAIN KILLER
20190338292 ยท 2019-11-07
Inventors
- Shin Chung (Yongin-si, KR)
- Daram Jung (Hwaseong-Si, KR)
- Bongjun Cho (Yongin-Si, KR)
- Kangwon Jang (Yongin-Si, KR)
- Hyun Ju Jeon (Yongin-Si, KR)
- Jinyoung Bae (Yongin-Si, KR)
- Taeyeon Bae (Yongin-Si, KR)
- Yeasel Jeon (Yongin-Si, KR)
- Jun Yeon Lee (Yongin-Si, KR)
- Sun Hwa Park (Siheung-Si, KR)
- Dan Bi An (Yongin-Si, KR)
Cpc classification
A61P29/00
HUMAN NECESSITIES
C12N15/113
CHEMISTRY; METALLURGY
C07K14/00
CHEMISTRY; METALLURGY
C12N15/1138
CHEMISTRY; METALLURGY
A61P43/00
HUMAN NECESSITIES
International classification
C12N15/113
CHEMISTRY; METALLURGY
Abstract
The current invention provides peptide nucleic acid derivatives targeting the 3 splice site of exon 4 in the human SCN9A pre-mRNA. The peptide nucleic acid derivatives potently induce SCN9A mRNA splice variant(s) lacking the SCN9A exon 4 in cells, and are useful to safely treat pains or conditions involving Na.sub.v1.7 activity.
Claims
1. A peptide nucleic acid derivative represented by Formula I, or a pharmaceutically acceptable salt thereof: ##STR00007## wherein, n is an integer between 10 and 25; the compound of Formula I possesses at least a 10-mer complementary overlap with a 14-mer pre-mRNA sequence of [(5.fwdarw.3) UGUUUAGGUACACU (SEQ ID NO: 2)] within the human SCN9A pre-mRNA; the compound of Formula I is fully complementary to the human SCN9A pre-mRNA, or partially complementary to the human SCN9A pre-mRNA with one or two mismatches; S.sub.1, S.sub.2, . . . , S.sub.n-1, S.sub.n, T.sub.1, T.sub.2, . . . , T.sub.n-1, and T.sub.n independently represent deuterido [D], hydrido [H], substituted or non-substituted alkyl, or substituted or non-substituted aryl radical; X and Y independently represent hydrido, formyl [HC(O)], aminocarbonyl [NH.sub.2C(O)], aminothiocarbonyl [NH.sub.2C(S)], substituted or non-substituted alkyl, substituted or non-substituted aryl, substituted or non-substituted alkylacyl, substituted or non-substituted arylacyl, substituted or non-substituted alkyloxycarbonyl, substituted or non-substituted aryloxycarbonyl, substituted or non-substituted alkylaminocarbonyl, substituted or non-substituted arylaminocarbonyl, substituted or non-substituted alkylaminothiocarbonyl, substituted or non-substituted arylaminothiocarbonyl, substituted or non-substituted alkyloxythiocarbonyl, substituted or non-substituted aryloxythiocarbonyl, substituted or non-substituted alkylsulfonyl, substituted or non-substituted arylsulfonyl, substituted or non-substituted alkylphosphonyl radical, or substituted or non-substituted arylphosphonyl radical; Z represents hydrido, hydroxy, substituted or non-substituted alkyloxy, substituted or non-substituted aryloxy, substituted or non-substituted amino, substituted or non-substituted alkyl, or substituted or non-substituted aryl radical; B.sub.1, B.sub.2, . . . , B.sub.n-1, and B.sub.n are independently selected from natural nucleobases including adenine, thymine, guanine, cytosine and uracil, and unnatural nucleobases; and, at least four of B.sub.1, B.sub.2, . . . , B.sub.n-1, and B.sub.n are independently selected from unnatural nucleobases with a substituted or non-substituted amino radical covalently linked to the nucleobase moiety.
2. The peptide nucleic acid derivative according to claim 1, or a pharmaceutical salt thereof: wherein, n is an integer between 10 and 25; the compound of Formula I possesses at least a 10-mer complementary overlap with the 14-mer pre-mRNA sequence of [(5.fwdarw.3) UGUUUAGGUACACU (SEQ ID NO: 2)] within the human SCN9A pre-mRNA; the compound of Formula I is fully complementary to the human SCN9A pre-mRNA, or partially complementary to the human SCN9A pre-mRNA with one or two mismatches; S.sub.1, S.sub.2, . . . , S.sub.n-1, S.sub.n, T.sub.1, T.sub.2, . . . , T.sub.n-1, and T.sub.n independently represent deuterido, hydrido, substituted or non-substituted alkyl, or substituted or non-substituted aryl radical; X and Y independently represent hydrido, formyl, aminocarbonyl, aminothiocarbonyl, substituted or non-substituted alkyl, substituted or non-substituted aryl, substituted or non-substituted alkylacyl, substituted or non-substituted arylacyl, substituted or non-substituted alkyloxycarbonyl, substituted or non-substituted aryloxycarbonyl, substituted or non-substituted alkylaminocarbonyl, substituted or non-substituted arylaminocarbonyl, substituted or non-substituted alkylaminothiocarbonyl, substituted or non-substituted arylaminothiocarbonyl, substituted or non-substituted alkyloxythiocarbonyl, substituted or non-substituted aryloxythiocarbonyl, substituted or non-substituted alkylsulfonyl, substituted or non-substituted arylsulfonyl, substituted or non-substituted alkylphosphonyl radical, or substituted or non-substituted arylphosphonyl radical; Z represents hydrido, hydroxy, substituted or non-substituted alkyloxy, substituted or non-substituted aryloxy, substituted or non-substituted amino, substituted or non-substituted alkyl, or substituted or non-substituted aryl radical; B.sub.1, B.sub.2, . . . , B.sub.n-1, and B.sub.n are independently selected from natural nucleobases including adenine, thymine, guanine, cytosine and uracil, and unnatural nucleobases; and, at least four of B.sub.1, B.sub.2, . . . , B.sub.n-1, and B.sub.n are independently selected from unnatural nucleobases represented by Formula II, Formula III, or Formula IV: ##STR00008## wherein, R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5 and R.sub.6 are independently selected from hydrido, and substituted or non-substituted alkyl radical; L.sub.1, L.sub.2 and L.sub.3 are a covalent linker represented by Formula V covalently linking the basic amino group to the nucleobase moiety: ##STR00009## wherein, Q.sub.1 and Q.sub.m are substituted or non-substituted methylene (CH.sub.2) radical, and Q.sub.m is directly linked to the basic amino group; Q.sub.2, Q.sub.3, . . . , and Q.sub.m-1 are independently selected from substituted or non-substituted methylene, oxygen (O), sulfur (S), and substituted or non-substituted amino radical [N(H), or N(substituent)-]; and, m is an integer between 1 and 15.
3. The peptide nucleic acid derivative of claim 2, wherein S.sub.1, S.sub.2, . . . , S.sub.n-1, S.sub.n, T.sub.1, T.sub.2, . . . , T.sub.n-1, and T.sub.n independently represent deuterido or hydrido radical and Z represents hydrido, hydroxy, substituted or non-substituted alkyloxy, substituted or non-substituted aryloxy, or substituted or non-substituted amino radical.
4. The peptide nucleic acid derivative of claim 2, wherein at least one of S.sub.1, S.sub.2, . . . , S.sub.n-1, S.sub.n, T.sub.1, T.sub.2, T.sub.n-1, and T.sub.n independently represents substituted or non-substituted alkyl, or substituted or non-substituted aryl radical, and/or Z represents substituted or non-substituted alkyl or substituted or non-substituted aryl radical.
5. The peptide nucleic acid derivative according to claim 1, or a pharmaceutical salt thereof: wherein, n is an integer between 11 and 21; the compound of Formula I possesses at least a 10-mer complementary overlap with the 14-mer pre-mRNA sequence of [(5.fwdarw.3) UGUUUAGGUACACU (SEQ ID NO: 2)] within the human SCN9A pre-mRNA; the compound of Formula I is fully complementary to the human SCN9A pre-mRNA, or partially complementary to the human SCN9A pre-mRNA with one or two mismatches; S.sub.1, S.sub.2, . . . , S.sub.n-1, S.sub.n, T.sub.1, T.sub.2, . . . , T.sub.n-1, and T.sub.n are hydrido radical; X and Y independently represent hydrido, substituted or non-substituted alkyl, substituted or non-substituted aryl, substituted or non-substituted alkylacyl, substituted or non-substituted arylacyl, substituted or non-substituted alkyloxycarbonyl, substituted or non-substituted aryloxycarbonyl, substituted or non-substituted alkylaminocarbonyl, substituted or non-substituted arylaminocarbonyl, substituted or non-substituted alkylsulfonyl, or substituted or non-substituted arylsulfonyl radical; Z represents substituted or non-substituted amino radical; B.sub.1, B.sub.2, . . . , B.sub.n-1, and B.sub.n are independently selected from natural nucleobases including adenine, thymine, guanine, cytosine and uracil, and unnatural nucleobases; at least four of B.sub.1, B.sub.2, . . . , B.sub.n-1, and B.sub.n are independently selected from unnatural nucleobases represented by Formula II, Formula III, or Formula IV; R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5 and R.sub.6 are independently selected from hydrido, and substituted or non-substituted alkyl radical; Q.sub.1 and Q.sub.m are substituted or non-substituted methylene radical, and Q.sub.m is directly linked to the basic amino group; Q.sub.2, Q.sub.3, . . . , and Q.sub.m-1 are independently selected from substituted or non-substituted methylene, oxygen, and amino radical; and, m is an integer between 1 and 11.
6. The peptide nucleic acid derivative of claim 5, wherein X and Y independently represent hydrido, substituted or non-substituted alkyl, substituted or non-substituted aryl, substituted or non-substituted alkylacyl, substituted or non-substituted arylacyl, substituted or non-substituted alkyloxycarbonyl, or substituted or non-substituted aryloxycarbonyl radical.
7. The peptide nucleic acid derivative of claim 5, wherein at least one of X and Y independently represents substituted or non-substituted alkylaminocarbonyl, substituted or non-substituted arylaminocarbonyl, substituted or non-substituted alkylsulfonyl, or substituted or non-substituted arylsulfonyl radical.
8. The peptide nucleic acid derivative according to claim 1, or a pharmaceutical salt thereof: wherein, n is an integer between 11 and 19; the compound of Formula I possesses at least a 10-mer complementary overlap with the 14-mer pre-mRNA sequence of [(5.fwdarw.3) UGUUUAGGUACACU (SEQ ID NO: 2)] within the human SCN9A pre-mRNA; the compound of Formula I is fully complementary to the human SCN9A pre-mRNA; S.sub.1, S.sub.2, . . . , S.sub.n-1, S.sub.n, T.sub.1, T.sub.2, . . . , T.sub.n-1, and T.sub.n are hydrido radical; X and Y independently represent hydrido, substituted or non-substituted alkyl, substituted or non-substituted aryl, substituted or non-substituted alkylacyl, substituted or non-substituted arylacyl, substituted or non-substituted alkyloxycarbonyl, substituted or non-substituted alkylaminocarbonyl, substituted or non-substituted alkylsulfonyl, or substituted or non-substituted arylsulfonyl radical; Z represents substituted or non-substituted amino radical; B.sub.1, B.sub.2, . . . , B.sub.n-1, and B.sub.n are independently selected from natural nucleobases including adenine, thymine, guanine, cytosine and uracil, and unnatural nucleobases; at least four of B.sub.1, B.sub.2, . . . , B.sub.n-1, and B.sub.n are independently selected from unnatural nucleobases represented by Formula II, Formula III, or Formula IV; R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5 and R.sub.6 are independently selected from hydrido, and substituted or non-substituted alkyl radical; Q.sub.1 and Q.sub.m are methylene radical, and Q.sub.m is directly linked to the basic amino group; Q.sub.2, Q.sub.3, . . . , and Q.sub.m-1 are independently selected from methylene, oxygen, and amino radical; and, m is an integer between 1 and 9.
9. The peptide nucleic acid derivative of claim 8, wherein X and Y independently represent hydrido, substituted or non-substituted alkylacyl, or substituted or non-substituted alkyloxycarbonyl radical.
10. The peptide nucleic acid derivative of claim 8, wherein at least one of X and Y independently represents substituted or non-substituted alkyl, substituted or non-substituted aryl, substituted or non-substituted arylacyl, substituted or non-substituted alkylaminocarbonyl, substituted or non-substituted alkylsulfonyl, or substituted or non-substituted arylsulfonyl radical.
11. The peptide nucleic acid derivative according to claim 1, or a pharmaceutical salt thereof: wherein, n is an integer between 11 and 19; the compound of Formula I possesses at least a 10-mer complementary overlap with the 14-mer pre-mRNA sequence of [(5.fwdarw.3) UGUUUAGGUACACU (SEQ ID NO: 2)] within the human SCN9A pre-mRNA; the compound of Formula I is fully complementary to the human SCN9A pre-mRNA; S.sub.1, S.sub.2, . . . , S.sub.n-1, S.sub.n, T.sub.1, T.sub.2, . . . , T.sub.n-1, and T.sub.n are hydrido radical; X and Y independently represent hydrido, substituted or non-substituted alkyl, substituted or non-substituted aryl, substituted or non-substituted alkylacyl, substituted or non-substituted arylacyl, or substituted or non-substituted alkyloxycarbonyl radical; Z represents substituted or non-substituted amino radical; B.sub.1, B.sub.2, . . . , B.sub.n-1, and B.sub.n are independently selected from natural nucleobases including adenine, thymine, guanine, cytosine and uracil, and unnatural nucleobases; at least four of B.sub.1, B.sub.2, . . . , B.sub.n-1, and B.sub.n are independently selected from unnatural nucleobases represented by Formula II, Formula III, or Formula IV; R.sub.1, R.sub.3, and R.sub.5 are hydrido radical, and R.sub.2, R.sub.4, and R.sub.6 independently represent hydrido, or substituted or non-substituted alkyl radical; Q.sub.1 and Q.sub.m are methylene radical, and Q.sub.m is directly linked to the basic amino group; Q.sub.2, Q.sub.3, . . . , and Q.sub.m-1 are independently selected from methylene, oxygen radical; and, m is an integer between 1 and 8.
12. The peptide nucleic acid derivative of claim 11, wherein X and Y independently represent hydrido, substituted or non-substituted alkylacyl, or substituted or non-substituted alkyloxycarbonyl radical.
13. The peptide nucleic acid derivative of claim 11, wherein at least one of X and Y independently represents substituted or non-substituted alkyl, substituted or non-substituted aryl, or substituted or non-substituted arylacyl radical.
14. The peptide nucleic acid derivative according to claim 1, or a pharmaceutical salt thereof: thereof: wherein, n is an integer between 11 and 19; the compound of Formula I possesses at least a 10-mer complementary overlap with the 14-mer pre-mRNA sequence of [(5.fwdarw.3) UGUUUAGGUACACU (SEQ ID NO: 2)] within the human SCN9A pre-mRNA; the compound of Formula I is fully complementary to the human SCN9A pre-mRNA; S.sub.1, S.sub.2, . . . , S.sub.n-1, S.sub.n, T.sub.1, T.sub.2, . . . , T.sub.n-1, and T.sub.n are hydrido radical; X and Y independently represent hydrido, substituted or non-substituted alkylacyl, substituted or non-substituted arylacyl, or substituted or non-substituted alkyloxycarbonyl radical; Z represents substituted or non-substituted amino radical; B.sub.1, B.sub.2, . . . , B.sub.n-1, and B.sub.n are independently selected from adenine, thymine, guanine, cytosine, and unnatural nucleobases; at least five of B.sub.1, B.sub.2, . . . , B.sub.n-1, and B.sub.n are independently selected from unnatural nucleobases represented by Formula II, Formula III, or Formula IV; R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, and R.sub.6 are hydrido radical; Q.sub.1 and Q.sub.m are methylene radical, and Q.sub.m is directly linked to the basic amino group; Q.sub.2, Q.sub.3, . . . , and Q.sub.m-1 are independently selected from methylene, and oxygen radical; and, m is an integer between 1 and 8.
15. The peptide nucleic acid derivative of claim 14, wherein X and Y independently represent hydrido, substituted or non-substituted alkylacyl, or substituted or non-substituted alkyloxycarbonyl radical.
16. The peptide nucleic acid derivative of claim 14, wherein at least one of X and Y independently represents substituted or non-substituted arylacyl.
17. The peptide nucleic acid derivative according to claim 1, or a pharmaceutical salt thereof: wherein, n is an integer between 11 and 19; the compound of Formula I possesses at least a 10-mer complementary overlap with the 14-mer pre-mRNA sequence of [(5.fwdarw.3) UGUUUAGGUACACU (SEQ ID NO: 2)] within the human SCN9A pre-mRNA; the compound of Formula I is fully complementary to the human SCN9A pre-mRNA; S.sub.1, S.sub.2, . . . , S.sub.n-1, S.sub.n, T.sub.1, T.sub.2, . . . , T.sub.n-1, and T.sub.n are hydrido radical; X is hydrido radical; Y represents substituted or non-substituted alkylacyl, substituted or non-substituted arylacyl, or substituted or non-substituted alkyloxycarbonyl radical; Z represents substituted or non-substituted amino radical; B.sub.1, B.sub.2, . . . , B.sub.n-1, and B.sub.n are independently selected from adenine, thymine, guanine, cytosine, and unnatural nucleobases; at least five of B.sub.1, B.sub.2, . . . , B.sub.n-1, and B.sub.n are independently selected from unnatural nucleobases represented by Formula II, Formula III, or Formula IV; R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, and R.sub.6 are hydrido radical; L.sub.1 represents (CH.sub.2).sub.2O(CH.sub.2).sub.2, CH.sub.2O(CH.sub.2).sub.2, CH.sub.2O(CH.sub.2).sub.3, CH.sub.2O(CH.sub.2).sub.4, or CH.sub.2O(CH.sub.2).sub.5 with the right end is directly linked to the basic amino group; and, L.sub.2 and L.sub.3 are independently selected from (CH.sub.2).sub.2, (CH.sub.2).sub.3, (CH.sub.2).sub.4, (CH.sub.2).sub.5, (CH.sub.2).sub.6, (CH.sub.2).sub.7, (CH.sub.2).sub.8, (CH.sub.2).sub.2O(CH.sub.2).sub.2, (CH.sub.2).sub.3O(CH.sub.2).sub.2, and (CH.sub.2).sub.2O(CH.sub.2).sub.3 with the right end is directly linked to the basic amino group.
18. The peptide nucleic acid derivative of claim 17, wherein Y represents substituted or non-substituted alkylacyl, substituted or non-substituted alkyloxycarbonyl radical, or substituted or non-substituted arylacyl.
19. (canceled)
20. The peptide nucleic acid derivative according to claim 1, which is selected from the group of peptide nucleic acid derivatives provided below, or a pharmaceutically acceptable salt thereof: TABLE-US-00016 (N.fwdarw. C)Fethoc-TA(5)A-A(5)AG(6)-TG(6)T-A(5)CC (1O2)-TA(5)A-A(5)-NH.sub.2; (N.fwdarw. C)Fethoc-TA(5)A-A(4)AG(6)-TG(6)T-A(5)CC (1O3)-TA(5)A-A-NH.sub.2; (N.fwdarw. C)Fmoc-TA(5)A-A(4)AG(6)-TG(6)T-A(5)CC(1O3)- TA(5)A-A-NH.sub.2; (N.fwdarw. C)Piv-Leu-TA(5)A-A(5)AG(3O2)-TG(6)T-A(5)CC (1O2)-TA(5)A-A(5)-NH.sub.2; (N.fwdarw. C)Fethoc-TA(5)T-A(5)AG(6)-TG(6)T-A(5)CC (1O2)-TA(5)A-A(5)-NH.sub.2; (N.fwdarw. C)Benzoyl-Gly-TA(2O2)A-A(5)AG(6)-TG(6)T-A(5) CT-TA(5)A-Lys-NH.sub.2; (N.fwdarw. C)Fethoc-AA(5)G-TG(6)T-A(5)CC(1O2)-TAA(5)-A- NH.sub.2; (N.fwdarw. C)Fethoc-AA(5)G-CG(6)T-A(5)CC(1O2)-TAA(5)-A- NH.sub.2; (N.fwdarw. C)Fmoc-AA(5)G-TG(6)T-A(5)CC(1O2)-TAA(5)-A- NH.sub.2; (N.fwdarw. C)Benzenesulfonyl-AA(5)G-TG(6)T-A(5)CC(1O2)- TAA(5)-A-NH.sub.2; (N.fwdarw. C)Ac-AA(5)G-TG(6)T-A(5)CC(1O2)-TAA(5)-A-NH.sub.2; (N.fwdarw. C)Fethoc-AA(5)G-TG(5)T-A(5)CC(1O2)-TA(3)A- A(5)-NH.sub.2; (N.fwdarw. C)Fmoc-AA(5)G-TG(6)T-AC(1O2)C-TAA(5)-A-NH.sub.2; (N.fwdarw. C)Methyl-AA(5)G-TG(5)T-A(5)CC(1O2)-TA(3)A- A(5)-Gly-Arg-NH.sub.2; (N.fwdarw. C)Fethoc-A(5)AG-TG(6)T-A(5)CC(1O2)-TAA-A(5)- NH.sub.2; (N.fwdarw. C)Ac-Val-A(5)AG-TG(6)T-A(5)CC(1O2)-TAA-A(5)- NH.sub.2; (N.fwdarw. C)Fethoc-AAG(6)-TG(6)T-A(5)CC(1O2)-TA(5)A-A- NH.sub.2; (N.fwdarw. C)Fethoc-AA(5)G-TG(5)T-A(5)CC(1O2)-TA(5)A- A(5)-NH.sub.2, (N.fwdarw. C)Fethoc-AA(5)G-TG(5)T-A(5)CC(1O2)-TA(5)A- A(5)C-NH.sub.2; (N.fwdarw. C)Fethoc-AA(5)G-TG(5)T-A(5)AC(1O2)-TA(5)T- A(5)C-NH.sub.2; (N.fwdarw. C)H-AA(5)G-TG(2O2)T-A(5)CC(1O2)-TA(5)A-A(5) C-NH.sub.2; (N.fwdarw. C)Fethoc-Lys-Leu-AA(5)G-TG(5)T-A(5)CC(1O2)- TA(2O2)A-A(5)C-Lys-NH.sub.2; (N.fwdarw. C)[N-(2-Phenylethyl)amino]carbonyl-AA(3)G-TG (5)T-A(5)CC(105)-TA(5)A-A(5)C-NH.sub.2; (N.fwdarw. C)N,N-Phenyl-Me-AA(5)G-TG(5)T-A(5)CC(1O2)-TA (5)A-A(4)C-NH.sub.2; (N.fwdarw. C)Fethoc-AA(5)G-TA(5)T-A(5)CC(1O2)-TG(5)A-A (5)C-NH.sub.2; (N.fwdarw. C)p-Toluenesulfonyl-AA(5)G-TG(5)T-A(5)CC (1O2)-TA(5)A-A(5)C-NH.sub.2; (N.fwdarw. C)p-Toluenesulfonyl-AA(5)G-TG(2O3)T-A(5)CC (1O2)-TA(5)A-A(5)C-Lys-NH.sub.2; (N.fwdarw. C)Fethoc-AA(5)G-TG(203)T-A(5)CC(1O3)-TA(7)A- A(5)C-NH.sub.2; (N.fwdarw. C)n-Propyl-AA(5)G-TG(5)T-A(5)CC(1O3)-TA(5)A- A(5)C-NH.sub.2; (N.fwdarw. C)Benzoyl-AA(5)G-TG(5)T-A(5)CC(1O2)-TA(5)A-A (5)C-NH.sub.2; (N.fwdarw. C)Benzyl-AA(5)G-TG(5)T-A(5)CC(1O3)-TA(5)A-A (5)C-NH.sub.2; (N.fwdarw. C)Benzoyl-AA(5)G-TG(3)T-A(5)CC(2O2)-TA(5)A-A (5)C-NH.sub.2; (N.fwdarw. C)Fethoc-AA(5)G-TG(5)T-A(5)CC(1O2)-TA(5)A-A (5)C-Leu-Lys-NH.sub.2; (N.fwdarw. C)Piv-AA(5)G-TG(5)T-A(5)CC(1O2)-TA(5)A-A(5) C-NH.sub.2; (N.fwdarw. C)Fethoc-TA(5)G-TG(5)T-A(5)CC(1O2)-TA(5)A-A (5)C-NH.sub.2; (N.fwdarw. C)Fethoc-AA(5)C-TG(5)T-A(5)CC(1O2)-TA(5)A-A (5)C-NH.sub.2; (N.fwdarw. C)Methylsulfonyl-AA(5)G-TG(5)T-A(5)CC(1O2)- TA(5)A-A(5)C-NH.sub.2; (N.fwdarw. C)n-Hexyl-AA(5)G-TG(5)T-A(5)CC(1O2)-TA(5)A- A(5)C-NH.sub.2; (N.fwdarw. C)n-Hexanoyl-AA(5)G-TG(5)T-A(5)CC(1O2)-TA(5) A-A(5)C-NH.sub.2; (N.fwdarw. C)n-Hexanoyl-AA(5)G-TG(5)T-A(5)CC(1O2)-TA(8) A-A(5)C-NH.sub.2; (N.fwdarw. C)Fethoc-AA(3)G-TG(2O2)T-A(5)CC(1O2)-TA(5)A- A(5)C-NH.sub.2; (N.fwdarw. C)Fethoc-AA(3)G-TG(2O2)T-A(5)CC(1O3)-TA(5)A- A(5)C-NH.sub.2; (N.fwdarw. C)Fethoc-AA(3)G-TG(2O2)T-A(5)CC(2O2)-TA(5)A- A(5)C-NH.sub.2; (N.fwdarw. C)FAM-HEX-HEX-AA(3)G-TG(2O2)T-A(5)CC(2O2)-TA (5)A-A(5)C-NH.sub.2; (N.fwdarw. C)Fethoc-A(5)GT-G(5)TA(5)-CC(1O2)T-A(5)AA (5)-C-NH.sub.2; (N.fwdarw. C)Fethoc-AG(5)T-G(7)TA-CC(1O2)T-AA(6)A-C- NH.sub.2; (N.fwdarw. C)Fethoc-AA(6)G-TG(5)T-A(6)CC(1O2)-TA(6)A-A (6)C-NH.sub.2; (N.fwdarw. C)Fethoc-AA(5)G-TG(5)T-A(5)CC(1O2)-TA(5)A-A (3)CA-C(1O5)AA-NH.sub.2; (N.fwdarw. C)Fethoc-AA(5)G-TCT-A(5)CC(1O2)-TA(5)A-A(3) CA-C(1O5)AA-NH.sub.2; (N.fwdarw. C)Fethoc-AA(5)G-TCT-A(5)CC(1O2)-TA(5)A-A(3) CA(3)-CTA-NH.sub.2; (N.fwdarw. C)Fethoc-TG(5)T-A(5)CC(1O2)-TA(5)A-A(3)CA- CA(7)A-NH.sub.2; (N.fwdarw. C)Fethoc-AA(5)G-TG(5)T-A(5)CC(1O2)-TA(5)A-A (3)CA(5)-C-NH.sub.2; (N.fwdarw. C)Fethoc-TG(5)T-A(5)CC(1O2)-TA(5)A-A(3)CA (5)-C-NH.sub.2; (N.fwdarw. C)p-Toluenesulfonyl-TG(2O3)T-A(5)CC(1O2)-TA (5)A-A(3)CA-C-Lys-NH.sub.2; (N.fwdarw. C)Fethoc-TG(5)T-A(5)CC(2O2)-TA(5)A-A(3)CA-CA (5)A-NH.sub.2; (N.fwdarw. C)Piv-TG(5)T-A(5)CC(2O2)-TA(5)A-A(3)CA-CA(5) A-NH.sub.2; (N.fwdarw. C)Benzoyl-TG(5)T-A(5)CC(2O2)-TA(5)A-A(3)CA- CA(5)A-NH.sub.2; (N.fwdarw. C)Propionyl-TG(5)T-A(5)CC(2O2)-TA(5)A-A(3) CA-CA(5)A-NH.sub.2; (N.fwdarw. C)Fethoc-TG(5)T-A(5)CC(2O2)-TA(5)A-A(3)CA-CA (5)A-Arg-Va1-NH.sub.2; (N.fwdarw. C)Fethoc-AA(5)G-TG(5)T-A(5)CC(1O2)-TA(5)A-A (5)G-NH.sub.2; (N.fwdarw. C)Fethoc-AG(5)G-TG(5)T-A(5)CC(1O2)-TA(5)A-A (5)G-NH.sub.2; (N.fwdarw. C)Fethoc-AA(5)G-TG(5)T-A(5)CC(1O2)-TA(5)A-A (5)CA-NH.sub.2; (N.fwdarw. C)Fethoc-AA(5)G-TG(5)T-A(5)CC(1O2)-TA(5)A-A (5)GG-NH.sub.2; and, (N.fwdarw. C)Fethoc-AA(5)G-TG(5)T-ACC(1O2)-TA(5)A-A(5) CA(5)-C-NH.sub.2: wherein, A, G, T, and C are PNA monomers with a natural nucleobase of adenine, guanine, thymine, and cytosine, respectively; C(pOq), A(p), A(pOq), G(p), and G(pOq) are PNA monomers with an unnatural nucleobase represented by Formula VI, Formula VII, Formula VIII, Formula IX, and Formula X, respectively; ##STR00010## wherein, p and q are integers; and, the abbreviations for the N- and C-terminus substituents are specifically defined as follows: Fmoc- is the abbreviation for [(9-fluorenyl)methyloxy]carbonyl-; Fethoc- for [2-(9-fluorenyl)ethyl-1-oxy]carbonyl; Ac- for acetyl-; n-Hexanoyl- for 1-(n-hexanoyl)-; Benzoyl- for benzenecabonyl-; Piv- for pivalyl-; n-Propyl- for 1-(n-propyl)-; n-Hexyl- for 1-(n-hexyl)-; H- for hydrido-; p-Toluenesulfonyl for (4-methylbenzene)-1-sulfonyl-; Benzenesulfonyl for benzene-1-sulfonyl-; Methylsulfonyl for methyl-1-sulfonyl-; -Lys- for amino acid residue lysine; -Val- for amino acid residue valine; -Leu- for amino acid residue leucine; -Arg- for amino acid residue arginine; -Gly- for amino acid residue glycine; [N-(2-Phenylethyl)amino]carbonyl- for [N-1-(2-phenylethyl)-amino]carbonyl-; Benzyl- for 1-(phenyl)methyl-; Phenyl- for phenyl-; Me- for methyl-; -HEX- for 6-amino-1-hexanoyl-, FAM- for 5, or 6-fluorescein-carbonyl- (isomeric mixture), and NH.sub.2 for non-substituted -amino group.
21. A method to treat a condition involving Na.sub.v1.7 activity or pain comprising administering the peptide nucleic acid derivative according to claim 1.
22. A method to treat chronic pain comprising administering the peptide nucleic acid derivative according to claim 1.
23. A method to treat neuropathic pain comprising administering the peptide nucleic acid derivative according to claim 1.
24. A method to treat pain involving Na.sub.v1.7 activity comprising administering the peptide nucleic acid derivative according to claim 1.
Description
BRIEF DESCRIPTION OF DRAWINGS
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SUMMARY OF INVENTION
[0091] The present invention provides a peptide nucleic acid derivative represented by Formula I, or a pharmaceutically acceptable salt thereof:
##STR00001##
[0092] wherein,
[0093] n is an integer between 10 and 25;
[0094] the compound of Formula I possesses at least a 10-mer complementary overlap with a 14-mer pre-mRNA sequence of [(5.fwdarw.3) UGUUUAGGUACACU (SEQ ID NO: 2)] within the human SCN9A pre-mRNA;
[0095] the compound of Formula I is fully complementary to the human SCN9A pre-mRNA, or partially complementary to the human SCN9A pre-mRNA with one or two mismatches;
[0096] S.sub.1, S.sub.2, . . . , S.sub.n-1, S.sub.n, T.sub.1, T.sub.2, . . . , T.sub.n-1, and T.sub.n independently represent deuterido [D], hydrido [H], substituted or non-substituted alkyl, or substituted or non-substituted aryl radical;
[0097] X and Y independently represent hydrido, formyl [HC(O)], aminocarbonyl [NH.sub.2C(O)], aminothiocarbonyl [NH.sub.2C(S)], substituted or non-substituted alkyl, substituted or non-substituted aryl, substituted or non-substituted alkylacyl, substituted or non-substituted arylacyl, substituted or non-substituted alkyloxycarbonyl, substituted or non-substituted aryloxycarbonyl, substituted or non-substituted alkylaminocarbonyl, substituted or non-substituted arylaminocarbonyl, substituted or non-substituted alkylaminothiocarbonyl, substituted or non-substituted arylaminothiocarbonyl, substituted or non-substituted alkyloxythiocarbonyl, substituted or non-substituted aryloxythiocarbonyl, substituted or non-substituted alkylsulfonyl, substituted or non-substituted arylsulfonyl, substituted or non-substituted alkylphosphonyl radical, or substituted or non-substituted arylphosphonyl radical;
[0098] Z represents hydrido, hydroxy, substituted or non-substituted alkyloxy, substituted or non-substituted aryloxy, substituted or non-substituted amino, substituted or non-substituted alkyl, or substituted or non-substituted aryl radical;
[0099] B.sub.1, B.sub.2, . . . , B.sub.n-1, and B.sub.n are independently selected from natural nucleobases including adenine, thymine, guanine, cytosine and uracil, and unnatural nucleobases; and,
[0100] at least four of B.sub.1, B.sub.2, . . . , B.sub.n-1, and B.sub.n are independently selected from unnatural nucleobases with a substituted or non-substituted amino radical covalently linked to the nucleobase moiety.
[0101] The compound of Formula I induces the skipping of exon 4 in the human SCN9A pre-mRNA, yields the human SCN9A mRNA splice variant(s) lacking exon 4, and therefore is useful to treat pains, or conditions involving Na.sub.v1.7 activity.
DESCRIPTION OF INVENTION
[0102] The present invention provides a peptide nucleic acid derivative represented by Formula I, or a pharmaceutically acceptable salt thereof:
##STR00002##
[0103] wherein,
[0104] n is an integer between 10 and 25;
[0105] the compound of Formula I possesses at least a 10-mer complementary overlap with a 14-mer pre-mRNA sequence of [(5.fwdarw.3) UGUUUAGGUACACU (SEQ ID NO: 2)] within the human SCN9A pre-mRNA;
[0106] the compound of Formula I is fully complementary to the human SCN9A pre-mRNA, or partially complementary to the human SCN9A pre-mRNA with one or two mismatches;
[0107] S.sub.1, S.sub.2, . . . , S.sub.n-1, S.sub.n, T.sub.1, T.sub.2, . . . , T.sub.n-1, and T.sub.n independently represent deuterido [D], hydrido [H], substituted or non-substituted alkyl, or substituted or non-substituted aryl radical;
[0108] X and Y independently represent hydrido, formyl [HC(O)], aminocarbonyl [NH.sub.2C(O)], aminothiocarbonyl [NH.sub.2C(S)], substituted or non-substituted alkyl, substituted or non-substituted aryl, substituted or non-substituted alkylacyl, substituted or non-substituted arylacyl, substituted or non-substituted alkyloxycarbonyl, substituted or non-substituted aryloxycarbonyl, substituted or non-substituted alkylaminocarbonyl, substituted or non-substituted arylaminocarbonyl, substituted or non-substituted alkylaminothiocarbonyl, substituted or non-substituted arylaminothiocarbonyl, substituted or non-substituted alkyloxythiocarbonyl, substituted or non-substituted aryloxythiocarbonyl, substituted or non-substituted alkylsulfonyl, substituted or non-substituted arylsulfonyl, substituted or non-substituted alkylphosphonyl radical, or substituted or non-substituted arylphosphonyl radical;
[0109] Z represents hydrido, hydroxy, substituted or non-substituted alkyloxy, substituted or non-substituted aryloxy, substituted or non-substituted amino, substituted or non-substituted alkyl, or substituted or non-substituted aryl radical;
[0110] B.sub.1, B.sub.2, . . . , B.sub.n-1, and B.sub.n are independently selected from natural nucleobases including adenine, thymine, guanine, cytosine and uracil, and unnatural nucleobases; and,
[0111] at least four of B.sub.1, B.sub.2, . . . , B.sub.n-1, and B.sub.n are independently selected from unnatural nucleobases with a substituted or non-substituted amino radical covalently linked to the nucleobase moiety.
[0112] The compound of Formula I induces the skipping of exon 4 in the human SCN9A pre-mRNA, yields the human SCN9A mRNA splice variant(s) lacking exon 4, and therefore is useful to treat pains, or conditions involving Na.sub.v1.7 activity.
[0113] In some embodiments, of the compound of Formula I, n is an integer selected from 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, and 24.
[0114] The compound of Formula I complementarily binds to the 3 splice site spanning the junction of intron 3 and exon 4 within the human SCN9A pre-mRNA read out form the genomic DNA [NCBI Reference Sequence: NC_000002.12]. The 14-mer sequence of [(5.fwdarw.3) UGUUUAGGUACACU (SEQ ID NO: 2)] within the human SCN9A pre-mRNA is a 3 splice site sequence consisting of 7-mer from intron 3 and 7-mer from exon 4. Thus the 14-mer pre-mRNA sequence may be conventionally expressed as [(5.fwdarw.3) uguuuag|GUACACU (SEQ ID NO: 2)], wherein the intron and exon sequences are denoted with small and capital letters, respectively, and the junction netween intron 3 and exon 4 is marked with |.
[0115] The conventional denotation for pre-mRNA is further illustrated by a 30-mer sequence of [(5.fwdarw.3) gaaucuuguguuuag|GUACACUUUUACUGG (SEQ ID NO: 3)] spanning the junction of intron 3 and exon 4 within the human SCN9A pre-mRNA. The exon numbering may vary depending on reported SCN9A mRNA transcripts. Provision of the 30-mer SCN9A sequence is to unequivocally identify the target splice site of the compound of Formula I regardless of the reported exon numbering of the SCN9A mRNA.
[0116] The chemical structures of natural (i.e., naturally occurring) or unnatural (i.e., non-naturally occurring) nucleobases in the PNA derivative of Formula I are exemplified in
[0117] The substituents adopted to describe the PNA derivative of Formula I are exemplified in
[0118] The compound of Formula I tightly binds to the complementary DNA as exemplified in the prior art [PCT/KR2009/001256]. The duplex between the PNA derivative of Formula I and its full-length complementary DNA or RNA possesses a T.sub.m value too high to be reliably determined in aqueous buffer. The PNA compound of Formula I yields high T.sub.m values with complementary DNAs of shorter length.
[0119] The compound of Formula I tightly binds to the target 3 splice site of the human SCN9A pre-mRNA transcribed from the human SCN9A gene, and interferes with the formation of splicesome early complex involving the compound's target exon. Since the compound of this invention sterically inhibits the formation of splicesome early complex, the SCN9A exon 4 is spliced out to yield SCN9A mRNA splice variant(s) lacking exon 4. Consequently the compound of this invention induces the skipping of exon 4 in the SCN9A mRNA.
[0120] Owing to the said compound's strong affinity for the complementary pre-mRNA sequence, the compound of this invention may also tightly bind to a partially complementary pre-mRNA sequence with one or two mismatches, and induce the skipping of the target exon within the SCN9A pre-mRNA. For example even if a 14-mer PNA derivative of Formula I possesses a single mismatch with the SCN9A pre-mRNA, the 14-mer SCN9A ASO still induces the skipping of exon 4 in the SCN9A mRNA.
[0121] The compound of Formula I possesses good cell permeability and can be readily delivered into cell as naked oligonucleotide as exemplified in the prior art [PCT/KR2009/001256]. Thus the compound of this invention induces the skipping of exon 4 in the SCN9A pre-mRNA to yield SCN9A mRNA splice variant(s) lacking SCN9A exon 4 in cells treated with the compound of Formula I as naked oligonucleotide. The said compound does not require any means or formulations for delivery into cell to potently induce the skipping of the target exon in cells. The compound of Formula I readily induces the skipping of the SCN9A exon 4 in cells treated with the compound of this invention as naked oligonucleotide at sub-femtomolar concentration.
[0122] Cells treated with the compound of Formula I as naked oligonucleotide express a lower level of the full-length SCN9A mRNA, and therefore show weaker Na.sub.v1.7 functional activity than cells without the compound treatment. The compound of Formula I inhibits Na.sub.v1.7 expression in neuronal cells or tissues upon systemic administration as naked oligonucleotide. Thus the said compound is useful to treat pains, or disorders involving excessive expression of Na.sub.v1.7.
[0123] The PNA derivative of Formula I can be systemically administered as naked oligonucleotide to induce the skipping of the SCN9A exon 4 in target tissues, and therefore inhibit the expression of the full-length SCN9A mRNA. The compound of Formula I does not require a particular formulation to increase the systemic delivery to target tissues for the intended therapeutic or biological activity. Usually the compound of Formula I is dissolved in PBS or saline, and systemically administered to elicit the desired therapeutic activity in target tissues. The compound of this invention does not need to be heavily or invasively formulated to elicit the systemic therapeutic activity.
[0124] The compound of Formula I may be used as combined with a pharmaceutically acceptable acid or base including but not limited to sodium hydroxide, potassium hydroxide, hydrochloric acid, methanesulfonic acid, citric acid, trifluoroacetic acid, and so on.
[0125] The PNA derivative of Formula I or a pharmaceutically acceptable salt thereof can be administered to a subject in combination with a pharmaceutically acceptable adjuvant including but not limited to citric acid, hydrochloric acid, tartaric acid, stearic acid, polyethyleneglycol, polypropyleneglycol, ethanol, isopropanol, sodium bicarbonate, distilled water, preservative(s), and so on.
[0126] The compound of the present invention can be systemically administered to a subject at a therapeutic dose of 1 fmole/Kg to higher than 1 nmole/Kg, which would vary depending on the dosing schedule, conditions or situations of the subject, and so on.
[0127] Preferred is a PNA derivative of Formula I, or a pharmaceutically acceptable salt thereof:
[0128] wherein,
[0129] n is an integer between 10 and 25;
[0130] the compound of Formula I possesses at least a 10-mer complementary overlap with the 14-mer pre-mRNA sequence of [(5.fwdarw.3) UGUUUAGGUACACU (SEQ ID NO: 2)] within the human SCN9A pre-mRNA;
[0131] the compound of Formula I is fully complementary to the human SCN9A pre-mRNA, or partially complementary to the human SCN9A pre-mRNA with one or two mismatches;
[0132] S.sub.1, S.sub.2, . . . , S.sub.n-1, S.sub.n, T.sub.1, T.sub.2, . . . , T.sub.n-1, and T.sub.n independently represent deuterido, hydrido, substituted or non-substituted alkyl, or substituted or non-substituted aryl radical;
[0133] X and Y independently represent hydrido, formyl, aminocarbonyl, aminothiocarbonyl, substituted or non-substituted alkyl, substituted or non-substituted aryl, substituted or non-substituted alkylacyl, substituted or non-substituted arylacyl, substituted or non-substituted alkyloxycarbonyl, substituted or non-substituted aryloxycarbonyl, substituted or non-substituted alkylaminocarbonyl, substituted or non-substituted arylaminocarbonyl, substituted or non-substituted alkylaminothiocarbonyl, substituted or non-substituted arylaminothiocarbonyl, substituted or non-substituted alkyloxythiocarbonyl, substituted or non-substituted aryloxythiocarbonyl, substituted or non-substituted alkylsulfonyl, substituted or non-substituted arylsulfonyl, substituted or non-substituted alkylphosphonyl radical, or substituted or non-substituted arylphosphonyl radical;
[0134] Z represents hydrido, hydroxy, substituted or non-substituted alkyloxy, substituted or non-substituted aryloxy, substituted or non-substituted amino, substituted or non-substituted alkyl, or substituted or non-substituted aryl radical;
[0135] B.sub.1, B.sub.2, . . . , B.sub.n-1, and B.sub.n are independently selected from natural nucleobases including adenine, thymine, guanine, cytosine and uracil, and unnatural nucleobases; and,
[0136] at least four of B.sub.1, B.sub.2, . . . , B.sub.n-1, and B.sub.n are independently selected from unnatural nucleobases represented by Formula II, Formula III, or Formula IV:
##STR00003##
[0137] wherein,
[0138] R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5 and R.sub.6 are independently selected from hydrido, and substituted or non-substituted alkyl radical;
[0139] L.sub.1, L.sub.2 and L.sub.3 are a covalent linker represented by Formula V covalently linking the basic amino group to the nucleobase moiety:
##STR00004##
[0140] wherein,
[0141] Q.sub.1 and Q.sub.m are substituted or non-substituted methylene (CH.sub.2) radical, and Q.sub.m is directly linked to the basic amino group;
[0142] Q.sub.2, Q.sub.3, . . . , and Q.sub.m-1 are independently selected from substituted or non-substituted methylene, oxygen (O), sulfur (S), and substituted or non-substituted amino radical [N(H), or N(substituent)-]; and,
[0143] m is an integer between 1 and 15.
[0144] In certain such embodiments, S.sub.1, S.sub.2, . . . , S.sub.n-1, S.sub.n, T.sub.1, T.sub.2, . . . , T.sub.n-1, and T.sub.n independently represent deuterido or hydrido radical and Z represents hydrido, hydroxy, substituted or non-substituted alkyloxy, substituted or non-substituted aryloxy, or substituted or non-substituted amino radical. In other such embodiments, at least one of S.sub.1, S.sub.2, . . . , S.sub.n-1, S.sub.n, T.sub.1, T.sub.2, . . . , T.sub.n-1, and T.sub.n independently represents substituted or non-substituted alkyl, or substituted or non-substituted aryl radical, and/or Z represents substituted or non-substituted alkyl or substituted or non-substituted aryl radical.
[0145] In some embodiments, m in Formula V an integer selected from 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, and 14.
[0146] Of interest is a PNA oligomer of Formula I, or a pharmaceutically acceptable salt thereof:
[0147] wherein,
[0148] n is an integer between 11 and 21;
[0149] the compound of Formula I possesses at least a 10-mer complementary overlap with the 14-mer pre-mRNA sequence of [(5.fwdarw.3) UGUUUAGGUACACU (SEQ ID NO: 2)] within the human SCN9A pre-mRNA;
[0150] the compound of Formula I is fully complementary to the human SCN9A pre-mRNA, or partially complementary to the human SCN9A pre-mRNA with one or two mismatches;
[0151] S.sub.1, S.sub.2, . . . , S.sub.n-1, S.sub.n, T.sub.1, T.sub.2, . . . , T.sub.n-1, and T.sub.n are hydrido radical;
[0152] X and Y independently represent hydrido, substituted or non-substituted alkyl, substituted or non-substituted aryl, substituted or non-substituted alkylacyl, substituted or non-substituted arylacyl, substituted or non-substituted alkyloxycarbonyl, substituted or non-substituted aryloxycarbonyl, substituted or non-substituted alkylaminocarbonyl, substituted or non-substituted arylaminocarbonyl, substituted or non-substituted alkylsulfonyl, or substituted or non-substituted arylsulfonyl radical;
[0153] Z represents substituted or non-substituted amino radical;
[0154] B.sub.1, B.sub.2, . . . , B.sub.n-1, and B.sub.nare independently selected from natural nucleobases including adenine, thymine, guanine, cytosine and uracil, and unnatural nucleobases;
[0155] at least four of B.sub.1, B.sub.2, . . . , B.sub.n-1, and B.sub.n are independently selected from unnatural nucleobases represented by Formula II, Formula III, or Formula IV;
[0156] R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5 and R.sub.6 are independently selected from hydrido, and substituted or non-substituted alkyl radical;
[0157] Q.sub.1 and Q.sub.m are substituted or non-substituted methylene radical, and Q.sub.m is directly linked to the basic amino group;
[0158] Q.sub.2, Q.sub.3, . . . , and Q.sub.m-1 are independently selected from substituted or non-substituted methylene, oxygen, and amino radical; and,
[0159] m is an integer between 1 and 11.
[0160] In one embodiment of the PNA oligomer of Formula I, or a pharmaceutically acceptable salt thereof, X and Y independently represent hydrido, substituted or non-substituted alkyl, substituted or non-substituted aryl, substituted or non-substituted alkylacyl, substituted or non-substituted arylacyl, substituted or non-substituted alkyloxycarbonyl, or substituted or non-substituted aryloxycarbonyl radical.
[0161] In another embodiment of the PNA oligomer of Formula I, or a pharmaceutically acceptable salt thereof, at least one of X and Y independently represents substituted or non-substituted alkylaminocarbonyl, substituted or non-substituted arylaminocarbonyl, substituted or non-substituted alkylsulfonyl, or substituted or non-substituted arylsulfonyl radical.
[0162] Of particular interest is a PNA derivative of Formula I, or a pharmaceutically acceptable salt thereof:
[0163] wherein,
[0164] n is an integer between 11 and 19;
[0165] the compound of Formula I possesses at least a 10-mer complementary overlap with the 14-mer pre-mRNA sequence of [(5.fwdarw.3) UGUUUAGGUACACU (SEQ ID NO: 2)] within the human SCN9A pre-mRNA;
[0166] the compound of Formula I is fully complementary to the human SCN9A pre-mRNA;
[0167] S.sub.1, S.sub.2, . . . , S.sub.n-1, S.sub.n, T.sub.1, T.sub.2, . . . , T.sub.n-1, and T.sub.n are hydrido radical;
[0168] X and Y independently represent hydrido, substituted or non-substituted alkyl, substituted or non-substituted aryl, substituted or non-substituted alkylacyl, substituted or non-substituted arylacyl, substituted or non-substituted alkyloxycarbonyl, substituted or non-substituted alkylaminocarbonyl, substituted or non-substituted alkylsulfonyl, or substituted or non-substituted arylsulfonyl radical;
[0169] Z represents substituted or non-substituted amino radical;
[0170] B.sub.1, B.sub.2, . . . , B.sub.n-1, and B.sub.n are independently selected from natural nucleobases including adenine, thymine, guanine, cytosine and uracil, and unnatural nucleobases;
[0171] at least four of B.sub.1, B.sub.2, . . . , B.sub.n-1, and B.sub.n are independently selected from unnatural nucleobases represented by Formula II, Formula III, or Formula IV;
[0172] R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5 and R.sub.6 are independently selected from hydrido, and substituted or non-substituted alkyl radical;
[0173] Q.sub.1 and Q.sub.m are methylene radical, and Q.sub.m is directly linked to the basic amino group;
[0174] Q.sub.2, Q.sub.3, . . . , and Q.sub.m-1 are independently selected from methylene, oxygen, and amino radical; and,
[0175] m is an integer between 1 and 9.
[0176] In one embodiment of the PNA oligomer of Formula I, or a pharmaceutically acceptable salt thereof, X and Y independently represent hydrido, substituted or non-substituted alkylacyl, or substituted or non-substituted alkyloxycarbonyl radical.
[0177] In another embodiment of the PNA oligomer of Formula I, or a pharmaceutically acceptable salt thereof, at least one of X and Y independently represents substituted or non-substituted alkyl, substituted or non-substituted aryl, substituted or non-substituted arylacyl, substituted or non-substituted alkylaminocarbonyl, substituted or non-substituted alkylsulfonyl, or substituted or non-substituted arylsulfonyl radical.
[0178] Of high interest is a PNA oligomer of Formula I, or a pharmaceutically acceptable salt thereof:
[0179] wherein,
[0180] n is an integer between 11 and 19;
[0181] the compound of Formula I possesses at least a 10-mer complementary overlap with the 14-mer pre-mRNA sequence of [(5.fwdarw.3) UGUUUAGGUACACU (SEQ ID NO: 2)] within the human SCN9A pre-mRNA;
[0182] the compound of Formula I is fully complementary to the human SCN9A pre-mRNA;
[0183] S.sub.1, S.sub.2, . . . , S.sub.n-1, S.sub.n, T.sub.1, T.sub.2, . . . , T.sub.n-1, and T.sub.n are hydrido radical;
[0184] X and Y independently represent hydrido, substituted or non-substituted alkyl, substituted or non-substituted aryl, substituted or non-substituted alkylacyl, substituted or non-substituted arylacyl, or substituted or non-substituted alkyloxycarbonyl radical;
[0185] Z represents substituted or non-substituted amino radical;
[0186] B.sub.1, B.sub.2, . . . , B.sub.n-1, and B.sub.n are independently selected from natural nucleobases including adenine, thymine, guanine, cytosine and uracil, and unnatural nucleobases;
[0187] at least four of B.sub.1, B.sub.2, . . . , B.sub.n-1, and B.sub.n are independently selected from unnatural nucleobases represented by Formula II, Formula III, or Formula IV;
[0188] R.sub.1, R.sub.3, and R.sub.5 are hydrido radical, and R.sub.2, R.sub.4, and R.sub.6 independently represent hydrido, or substituted or non-substituted alkyl radical;
[0189] Q.sub.1 and Q.sub.m are methylene radical, and Q.sub.m is directly linked to the basic amino group;
[0190] Q.sub.2, Q.sub.3, . . . , and Q.sub.m-1 are independently selected from methylene, oxygen radical; and,
[0191] m is an integer between 1 and 8.
[0192] In one embodiment of the PNA oligomer of Formula I, or a pharmaceutically acceptable salt thereof, X and Y independently represent hydrido, substituted or non-substituted alkylacyl, or substituted or non-substituted alkyloxycarbonyl radical.
[0193] In another embodiment of the PNA oligomer of Formula I, or a pharmaceutically acceptable salt thereof, at least one of X and Y independently represents substituted or non-substituted alkyl, substituted or non-substituted aryl, or substituted or non-substituted arylacyl.
[0194] Of higher interest is a PNA derivative of Formula I, or a pharmaceutically acceptable salt thereof:
[0195] wherein,
[0196] n is an integer between 11 and 19;
[0197] the compound of Formula I possesses at least a 10-mer complementary overlap with the 14-mer pre-mRNA sequence of [(5.fwdarw.3) UGUUUAGGUACACU (SEQ ID NO: 2)] within the human SCN9A pre-mRNA;
[0198] the compound of Formula I is fully complementary to the human SCN9A pre-mRNA;
[0199] S.sub.1, S.sub.2, . . . , S.sub.n-1, S.sub.n, T.sub.1, T.sub.2, . . . , T.sub.n-1, and T.sub.n are hydrido radical;
[0200] X and Y independently represent hydrido, substituted or non-substituted alkylacyl, substituted or non-substituted arylacyl, or substituted or non-substituted alkyloxycarbonyl radical;
[0201] Z represents substituted or non-substituted amino radical;
[0202] B.sub.1, B.sub.2, . . . , B.sub.n-1, and B.sub.n are independently selected from adenine, thymine, guanine, cytosine, and unnatural nucleobases;
[0203] at least five of B.sub.1, B.sub.2, . . . , B.sub.n-1, and B.sub.n are independently selected from unnatural nucleobases represented by Formula II, Formula III, or Formula IV;
[0204] R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, and R.sub.6 are hydrido radical;
[0205] Q.sub.1 and Q.sub.m are methylene radical, and Q.sub.m is directly linked to the basic amino group;
[0206] Q.sub.2, Q.sub.3, . . . , and Q.sub.m-1 are independently selected from methylene, and oxygen radical; and,
[0207] m is an integer between 1 and 8.
[0208] In one embodiment of the PNA oligomer of Formula I, or a pharmaceutically acceptable salt thereof, X and Y independently represent hydrido, substituted or non-substituted alkylacyl, or substituted or non-substituted alkyloxycarbonyl radical.
[0209] In one embodiment of the PNA oligomer of Formula I, or a pharmaceutically acceptable salt thereof, at least one of X and Y independently represents substituted or non-substituted arylacyl radical.
[0210] Of highest interest is a PNA derivative of Formula I, or a pharmaceutically acceptable salt thereof:
[0211] wherein,
[0212] n is an integer between 11 and 19;
[0213] the compound of Formula I possesses at least a 10-mer complementary overlap with the 14-mer pre-mRNA sequence of [(5.fwdarw.3) UGUUUAGGUACACU (SEQ ID NO: 2)] within the human SCN9A pre-mRNA;
[0214] the compound of Formula I is fully complementary to the human SCN9A pre-mRNA;
[0215] S.sub.1, S.sub.2, . . . , S.sub.n-1, S.sub.n, T.sub.1, T.sub.2, . . . , T.sub.n-1,and T.sub.n are hydrido radical;
[0216] X is hydrido radical;
[0217] Y represents substituted or non-substituted alkylacyl, substituted or non-substituted arylacyl, or substituted or non-substituted alkyloxycarbonyl radical;
[0218] Z represents substituted or non-substituted amino radical;
[0219] B.sub.1, B.sub.2, . . . , B.sub.n-1, and B.sub.n are independently selected from adenine, thymine, guanine, cytosine, and unnatural nucleobases;
[0220] at least five of B.sub.1, B.sub.2, . . . , B.sub.n-1, and B.sub.n are independently selected from unnatural nucleobases represented by Formula II, Formula III, or Formula IV;
[0221] R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, and R.sub.6 are hydrido radical;
[0222] L.sub.1 represents (CH.sub.2).sub.2O(CH.sub.2).sub.2, CH.sub.2O(CH.sub.2).sub.2, CH.sub.2O(CH.sub.2).sub.3, CH.sub.2O(CH.sub.2).sub.4, or CH.sub.2O(CH.sub.2).sub.5 with the right end is directly linked to the basic amino group; and,
[0223] L.sub.2 and L.sub.3 are independently selected from (CH.sub.2).sub.2, (CH.sub.2).sub.3, (CH.sub.2).sub.4, (CH.sub.2).sub.5, (CH.sub.2).sub.6, (CH.sub.2).sub.7, (CH.sub.2).sub.8, (CH.sub.2).sub.2O(CH.sub.2).sub.2, (CH.sub.2).sub.3O(CH.sub.2).sub.2, and (CH.sub.2).sub.2O(CH.sub.2).sub.3 with the right end is directly linked to the basic amino group.
[0224] In one embodiment of the PNA oligomer of Formula I, or a pharmaceutically acceptable salt thereof, Y represents substituted or non-substituted alkylacyl or substituted or non-substituted alkyloxycarbonyl radical.
[0225] In another embodiment of the PNA oligomer of Formula I, or a pharmaceutically acceptable salt thereof, Y represents substituted or non-substituted arylacyl.
[0226] Of specific interest is a PNA derivative of Formula I which is selected from the group of compounds provided below, or a pharmaceutically acceptable salt thereof:
TABLE-US-00001 (N.fwdarw. C)Fethoc-TA(5)A-A(5)AG(6)-TG(6)T-A(5)CC (1O2)-TA(5)A-A(5)-NH.sub.2; (N.fwdarw. C)Fethoc-TA(5)A-A(4)AG(6)-TG(6)T-A(5)CC (1O3)-TA(5)A-A-NH.sub.2; (N.fwdarw. C)Fmoc-TA(5)A-A(4)AG(6)-TG(6)T-A(5)CC(1O3)- TA(5)A-A-NH.sub.2; (N.fwdarw. C)Piv-Leu-TA(5)A-A(5)AG(3O2)-TG(6)T-A(5)CC (1O2)-TA(5)A-A(5)-NH.sub.2; (N.fwdarw. C)Fethoc-TA(5)T-A(5)AG(6)-TG(6)T-A(5)CC (1O2)-TA(5)A-A(5)-NH.sub.2; (N.fwdarw. C)Benzoyl-Gly-TA(2O2)A-A(5)AG(6)-TG(6)T-A(5) CT-TA(5)A-Lys-NH.sub.2; (N.fwdarw. C)Fethoc-AA(5)G-TG(6)T-A(5)CC(1O2)-TAA(5)-A- NH.sub.2; (N.fwdarw. C)Fethoc-AA(5)G-CG(6)T-A(5)CC(1O2)-TAA(5)-A- NH.sub.2; (N.fwdarw. C)Fmoc-AA(5)G-TG(6)T-A(5)CC(1O2)-TAA(5)-A- NH.sub.2; (N.fwdarw. C)Benzenesulfonyl-AA(5)G-TG(6)T-A(5)CC(1O2)- TAA(5)-A-NH.sub.2; (N.fwdarw. C)Ac-AA(5)G-TG(6)T-A(5)CC(1O2)-TAA(5)-A-NH.sub.2; (N.fwdarw. C)Fethoc-AA(5)G-TG(5)T-A(5)CC(1O2)-TA(3)A-A (5)-NH.sub.2; (N.fwdarw. C)Fmoc-AA(5)G-TG(6)T-AC(1O2)C-TAA(5)-A-NH.sub.2; (N.fwdarw. C)Methyl-AA(5)G-TG(5)T-A(5)CC(1O2)-TA(3)A-A (5)-Gly-Arg-NH.sub.2; (N.fwdarw. C)Fethoc-A(5)AG-TG(6)T-A(5)CC(1O2)-TAA-A(5)- NH.sub.2; (N.fwdarw. C)Ac-Val-A(5)AG-TG(6)T-A(5)CC(1O2)-TAA-A(5)- NH.sub.2; (N.fwdarw. C)Fethoc-AAG(6)-TG(6)T-A(5)CC(1O2)-TA(5)A-A- NH.sub.2; (N.fwdarw. C)Fethoc-AA(5)G-TG(5)T-A(5)CC(1O2)-TA(5)A-A (5)-NH.sub.2, (N.fwdarw. C)Fethoc-AA(5)G-TG(5)T-A(5)CC(1O2)-TA(5)A-A (5)C-NH.sub.2; (N.fwdarw. C)Fethoc-AA(5)G-TG(5)T-A(5)AC(1O2)-TA(5)T-A (5)C-NH.sub.2; (N.fwdarw. C)H-AA(5)G-TG(2O2)T-A(5)CC(1O2)-TA(5)A-A(5) C-NH.sub.2; (N.fwdarw. C)Fethoc-Lys-Leu-AA(5)G-TG(5)T-A(5)CC(1O2)- TA(2O2)A-A(5)C-Lys-NH.sub.2; (N.fwdarw. C)[N-(2-Phenylethyl)amino]carbonyl-AA(3)G-TG (5)T-A(5)CC(105)-TA(5)A-A(5)C-NH.sub.2; (N.fwdarw. C)N,N-Phenyl-Me-AA(5)G-TG(5)T-A(5)CC(1O2)-TA (5)A-A(4)C-NH.sub.2; (N.fwdarw. C)Fethoc-AA(5)G-TA(5)T-A(5)CC(1O2)-TG(5)A-A (5)C-NH.sub.2; (N.fwdarw. C)p-Toluenesulfonyl-AA(5)G-TG(5)T-A(5)CC (1O2)-TA(5)A-A(5)C-NH.sub.2; (N.fwdarw. C)p-Toluenesulfonyl-AA(5)G-TG(203)T-A(5)CC (1O2)-TA(5)A-A(5)C-Lys-NH.sub.2; (N.fwdarw. C)Fethoc-AA(5)G-TG(2O3)T-A(5)CC(1O3)-TA(7)A- A(5)C-NH.sub.2; (N.fwdarw. C)n-Propyl-AA(5)G-TG(5)T-A(5)CC(1O3)-TA(5)A- A(5)C-NH.sub.2; (N.fwdarw. C)Benzoyl-AA(5)G-TG(5)T-A(5)CC(1O2)-TA(5)A-A (5)C-NH.sub.2; (N.fwdarw. C)Benzyl-AA(5)G-TG(5)T-A(5)CC(1O3)-TA(5)A-A (5)C-NH.sub.2; (N.fwdarw. C)Benzoyl-AA(5)G-TG(3)T-A(5)CC(2O2)-TA(5)A-A (5)C-NH.sub.2; (N.fwdarw. C)Fethoc-AA(5)G-TG(5)T-A(5)CC(1O2)-TA(5)A-A (5)C-Leu-Lys-NH.sub.2; (N.fwdarw. C)Piv-AA(5)G-TG(5)T-A(5)CC(1O2)-TA(5)A-A(5) C-NH.sub.2; (N.fwdarw. C)Fethoc-TA(5)G-TG(5)T-A(5)CC(1O2)-TA(5)A-A (5)C-NH.sub.2; (N.fwdarw. C)Fethoc-AA(5)C-TG(5)T-A(5)CC(1O2)-TA(5)A-A (5)C-NH.sub.2; (N.fwdarw. C)Methylsulfonyl-AA(5)G-TG(5)T-A(5)CC(1O2)- TA(5)A-A(5)C-NH.sub.2; (N.fwdarw. C)n-Hexyl-AA(5)G-TG(5)T-A(5)CC(1O2)-TA(5)A- A(5)C-NH.sub.2; (N.fwdarw. C)n-Hexanoyl-AA(5)G-TG(5)T-A(5)CC(1O2)-TA(5) A-A(5)C-NH.sub.2; (N.fwdarw. C)n-Hexanoyl-AA(5)G-TG(5)T-A(5)CC(1O2)-TA(8) A-A(5)C-NH.sub.2; (N.fwdarw. C)Fethoc-AA(3)G-TG(2O2)T-A(5)CC(1O2)-TA(5)A- A(5)C-NH.sub.2; (N.fwdarw. C)Fethoc-AA(3)G-TG(2O2)T-A(5)CC(1O3)-TA(5)A- A(5)C-NH.sub.2; (N.fwdarw. C)Fethoc-AA(3)G-TG(2O2)T-A(5)CC(2O2)-TA(5)A- A(5)C-NH.sub.2; (N.fwdarw. C)FAM-HEX-HEX-AA(3)G-TG(2O2)T-A(5)CC(2O2)-TA (5)A-A(5)C-NH.sub.2; (N.fwdarw. C)Fethoc-A(5)GT-G(5)TA(5)-CC(1O2)T-A(5)AA (5)-C-NH.sub.2; (N.fwdarw. C)Fethoc-AG(5)T-G(7)TA-CC(1O2)T-AA(6)A-C- NH.sub.2; (N.fwdarw. C)Fethoc-AA(6)G-TG(5)T-A(6)CC(1O2)-TA(6)A-A (6)C-NH.sub.2; (N.fwdarw. C)Fethoc-AA(5)G-TG(5)T-A(5)CC(1O2)-TA(5)A-A (3)CA-C(1O5)AA-NH.sub.2; (N.fwdarw. C)Fethoc-AA(5)G-TCT-A(5)CC(1O2)-TA(5)A-A(3) CA-C(1O5)AA-NH.sub.2; (N.fwdarw. C)Fethoc-AA(5)G-TCT-A(5)CC(1O2)-TA(5)A-A(3) CA(3)-CTA-NH.sub.2; (N.fwdarw. C)Fethoc-TG(5)T-A(5)CC(1O2)-TA(5)A-A(3)CA-CA (7)A-NH.sub.2; (N.fwdarw. C)Fethoc-AA(5)G-TG(5)T-A(5)CC(1O2)-TA(5)A-A (3)CA(5)-C-NH.sub.2; (N.fwdarw. C)Fethoc-TG(5)T-A(5)CC(1O2)-TA(5)A-A(3)CA (5)-C-NH.sub.2; (N.fwdarw. C)p-Toluenesulfonyl-TG(2O3)T-A(5)CC(1O2)-TA (5)A-A(3)CA-C-Lys-NH.sub.2; (N.fwdarw. C)Fethoc-TG(5)T-A(5)CC(2O2)-TA(5)A-A(3)CA-CA (5)A-NH.sub.2; (N.fwdarw. C)Piv-TG(5)T-A(5)CC(2O2)-TA(5)A-A(3)CA-CA(5) A-NH.sub.2; (N.fwdarw. C)Benzoyl-TG(5)T-A(5)CC(2O2)-TA(5)A-A(3)CA- CA(5)A-NH.sub.2; (N.fwdarw. C)Propionyl-TG(5)T-A(5)CC(2O2)-TA(5)A-A(3) CA-CA(5)A-NH.sub.2; (N.fwdarw. C)Fethoc-TG(5)T-A(5)CC(2O2)-TA(5)A-A(3)CA-CA (5)A-Arg-Val-NH.sub.2; (N.fwdarw. C)Fethoc-AA(5)G-TG(5)T-A(5)CC(1O2)-TA(5)A-A (5)G-NH.sub.2; (N.fwdarw. C)Fethoc-AG(5)G-TG(5)T-A(5)CC(1O2)-TA(5)A-A (5)G-NH.sub.2; (N.fwdarw. C)Fethoc-AA(5)G-TG(5)T-A(5)CC(1O2)-TA(5)A-A (5)CA-NH.sub.2; (N.fwdarw. C)Fethoc-AA(5)G-TG(5)T-A(5)CC(1O2)-TA(5)A-A (5)GG-NH.sub.2; and, (N.fwdarw. C)Fethoc-AA(5)G-TG(5)T-ACC(1O2)-TA(5)A-A(5) CA(5)-C-NH.sub.2:
[0227] wherein,
[0228] A, G, T, and C are PNA monomers with a natural nucleobase of adenine, guanine, thymine, and cytosine, respectively;
[0229] C(pOq), A(p), A(pOq), G(p), and G(pOq) are PNA monomers with an unnatural nucleobase represented by Formula VI, Formula VII, Formula VIII, Formula IX, and Formula X, respectively;
##STR00005##
[0230] wherein,
[0231] p and q are integers; and,
[0232] the abbreviations for the N- and C-terminus substituents are specifically defined as follows: Fmoc- is the abbreviation for [(9-fluorenyl)methyloxy]carbonyl-; Fethoc- for [2-(9-fluorenyl)ethyl-1-oxy]carbonyl; Ac- for acetyl-; n-Hexanoyl- for 1-(n-hexanoyl-; Benzoyl- for benzenecabonyl-; Piv- for pivalyl-; n-Propyl- for 1-(n-propyl)-; n-Hexyl- for 1-(n-hexyl)-; H- for hydrido-; p-Toluenesulfonyl for (4-methylbenzene)-1-sulfonyl-; Benzenesulfonyl for benzene-1-sulfonyl-; Methylsulfonyl for methyl-1-sulfonyl-; -Lys- for amino acid residue lysine; -Val- for amino acid residue valine; -Leu- for amino acid residue leucine; -Arg- for amino acid residue arginine; -Gly- for amino acid residue glycine; [N-(2-Phenylethyl)amino]carbonyl- for [N-1-(2-phenylethyl)-amino]carbonyl-; Benzyl- for 1-(phenyl)methyl-; Phenyl- for phenyl-; Me- for methyl-; -HEX- for 6-amino-1-hexanoyl-, FAM- for 5, or 6-fluorescein-carbonyl- (isomeric mixture), and NH.sub.2 for non-substituted -amino group.
[0233]
[0234]
[0235] In order to illustrate the abbreviations for PNA derivatives, the chemical structure for a 14-mer PNA derivative denoted as (N.fwdarw.C) Fethoc-TA(5)A-A(5)TA(5)-CGC(1O2)-AA(5)A-A(5)A-NH.sub.2 is provided in
[0236] A 14-mer PNA sequence of (N.fwdarw.C) Fethoc-AA(3)G-TG(2O2)T-A(5)CC(1O2)-TA(5)A-A(5)C-NH.sub.2 is equivalent to the DNA sequence of (5.fwdarw.3) AAG-TGT-ACC-TAA-AC (SEQ ID NO: 4), which has a 14-mer complementary overlap with a 20-mer pre-mRNA sequence as marked bold and underlined in
TABLE-US-00002 [(5 .fwdarw. 3)uuguguuuag| GUACACUUUU(SEQIDNO:5)]
spanning the junction of intron 3 and exon 4 within the human SCN9A pre-mRNA.
[0237] A 18-mer PNA sequence of (N.fwdarw.C) Fethoc-AA(5)G-TG(5)T-A(5)CC(1O2)-TA(5)A-A(3)CA-C(1O5)AA-NH.sub.2 is equivalent to the DNA sequence of (5.fwdarw.3) AAG-TGT-ACC-TAA-ACA-CAA (SEQ ID NO: 6), which has a 18-mer complementary overlap with the 20-mer SCN9A pre-mRNA sequence as marked bold and underlined in
TABLE-US-00003 [(5 .fwdarw. 3)uuguauuuag| GUACACUUUU(SEQIDNO:5)]
[0238] A 18-mer PNA sequence of (N.fwdarw.C) Fethoc-AA(5)G-TCT-A(5)CC(1O2)-TA(5)A-A(3)CA(3)-CTA-NH.sub.2 is equivalent to the DNA sequence of (5.fwdarw.3) AAG-TCT-ACC-TAA-ACA-CTA (SEQ ID NO: 7), which has a 16-mer complementary overlap with the 20-mer SCN9A pre-mRNA sequence as marked bold and underlined in [(5.fwdarw.3) uuguguuuag|GUACACUUUU (SEQ ID NO: 5)]. Thus the 18-mer PNA has two single mismatches with the 3 splice site of exon 4 in the human SCN9A pre-mRNA. The two single mismatches are found in intron 3 and in exon 4 as marked with quote sign ( ).
[0239] A 14-mer PNA sequence of (N.fwdarw.C) Fethoc-AA(5)G-TG(5)T-A(5)CC(1O2)-TA(5)A-A(5)G-NH.sub.2 is equivalent to the DNA sequence of (5.fwdarw.3) AAG-TGT-ACC-TAA-AG (SEQ ID NO: 8), which has a 13-mer complementary overlap with the 20-mer SCN9A pre-mRNA sequence as marked bold and underlined in
TABLE-US-00004 [(5 .fwdarw. 3)uuguguuuag| GUACACUUUU(SEQIDNO: 5)]
Thus the 14-mer PNA has a single mismatch with the 3 splice site of exon 4 in the human SCN9A pre-mRNA. The single mismatch is found in intron 3 as marked with quote sign ( ).
DETAILED DESCRIPTION OF INVENTION
General Procedures for Preparation of PNA Oligomers
[0240] PNA oligomers were synthesized by solid phase peptide synthesis (SPPS) based on Fmoc-chemistry according to the method disclosed in the prior art [U.S. Pat. No. 6,133,444; WO 96/40685] with minor modifications if needed. The solid support employed in this study was H-Rink Amide-ChemMatrix purchased from PCAS BioMatrix Inc. (Quebec, Canada). Fmoc-PNA monomers with a modified nucleobase were synthesized as described in the prior art [PCT/KR 2009/001256] or with minor modifications. Such Fmoc-PNA monomers with a modified nucleobase and Fmoc-PNA monomers with a natural nucleobase were used to synthesize the PNA derivatives of the present invention. The Fmoc-PNA monomers with a modified nucleobase are provided in
[0241]
[0242] [Activation of H-Rink-ChemMatrix Resin] 0.01 mmol (ca 20 mg resin) of the ChemMatrix resin in 1.5 mL 20% piperidine/DMF was vortexed in a libra tube for 20 min, and the DeFmoc solution was filtered off. The resin was washed for 30 sec each in series with 1.5 mL methylene chloride (MC), 1.5 mL dimethylformamide (DMF), 1.5 mL MC, 1.5 mL DMF, and 1.5 mL MC. The resulting free amines on the solid support were subjected to coupling either with an Fmoc-PNA monomer or with an Fmoc-protected amino acid derivative.
[0243] [DeFmoc] The resin was vortexed in 1.5 mL 20% piperidine/DMF for 7 min, and the DeFmoc solution was filtered off. The resin was washed for 30 sec each in series with 1.5 mL MC, 1.5 mL DMF, 1.5 mL MC, 1.5 mL DMF, and 1.5 mL MC. The resulting free amines on the solid support were immediately subjected to coupling with an Fmoc-PNA monomer.
[0244] [Coupling with Fmoc-PNA Monomer] The free amines on the solid support were coupled with an Fmoc-PNA monomer as follows. 0.04 mmol of an Fmoc-PNA monomer, 0.05 mmol HBTU [2-(1H-benzotriazol-1-yl)-1,1,3,3-tetramethyluronium hexafluorophosphate], and 10 mmol DIEA (N,N-diisopropylethylamine) were incubated for 2 min in 1 mL anhydrous DMF, and added to the resin with free amines The resin solution was vortexed for 1 hour and the reaction medium was filtered off. Then the resin was washed for 30 sec each in series with 1.5 mL MC, 1.5 mL DMF, and 1.5 mL MC.
[0245] [Capping] Following the coupling reaction, the unreacted free amines were capped by shaking for 5 min in 1.5 mL capping solution (5% acetic anhydride and 6% 2,6-leutidine in DMF). Then the capping solution was filtered off and washed for 30 sec each in series with 1.5 mL MC, 1.5 mL DMF, and 1.5 mL MC.
[0246] [Introduction of Fethoc- Radical in N-Terminus] Fethoc- radical was introduced to the N-terminus by reacting the free amines on the resin with Fethoc-OSu under usual basic coupling conditions. The chemical structure of Fethoc-OSu [CAS No. 179337-69-0, C.sub.20H.sub.17NO.sub.5, MW 351.36] is provided as follows.
##STR00006##
[0247] [Cleavage from Resin] PNA oligomers bound to the resin were cleaved from the resin by shaking for 3 hours in 1.5 mL cleavage solution (2.5% tri-isopropylsilane and 2.5% water in trifluoroacetic acid). The resin was filtered off and the filtrate was concentrated under reduced pressure. The resulting residue was triturated with diethylether and the resulting precipitate was collected by filtration for purification by reverse phase HPLC.
[0248] [HPLC Analysis and Purification] Following a cleavage from resin, the crude product of each PNA derivative was purified by C.sub.18-reverse phase HPLC eluting water/acetonitrile or water/methanol (gradient method) containing 0.1% TFA.
Synthetic Examples for PNA Derivative of Formula I
[0249] In order to complementarily target the 3 splice site spanning the junction of intron 3 and exon 4 within the human SCN9A pre-mRNA, PNA derivatives of this invention were prepared according to the synthetic procedures provided above or with minor modifications. Provision of such PNA derivatives targeting the human SCN9A pre-mRNA is to exemplify the PNA derivatives of Formula I, and should not be interpreted to limit the scope of the present invention.
[0250] Table 1 provides PNA derivatives complementarily targeting the 3 splice site of exon 4 in the human SCN9A pre-mRNA along with structural characterization data by mass spectrometry. Provision of the SCN9A ASOs in Table 1 is to exemplify the PNA derivatives of Formula I, and should not be interpreted to limit the scope of the present invention.
TABLE-US-00005 TABLE1 PNAderivativescomplementarilytargetingthe3;splicesitespanningthejunction ofintron3andexon4withinthehumanSCN9Apre-mRNAalongwithstructural characterizationdatabymassspectrometry. PNA ExactMass,m/z Example PNASequence(N.fwdarw. C) theor..sup.a obs..sup.b ASO1 Fethoc-TA(5)A-A(5)AG(6)-TG(6)T-A(5)CC(1O2)- 5398.60 5398.58 TA(5)A-A(5)-NH.sub.2 ASO2 Fethoc-AA(5)G-TG(6)T-A(5)CC(1O2)-TAA(5)-A-NH.sub.2 4282.97 4284.99 ASO3 Fethoc-AA(5)G-TG(6)T-AC(1O2)C-TAA(5)-A-NH.sub.2 4182.87 4182.89 ASO4 Fethoc-A(5)AG-TG(6)T-A(5)CC(1O2)-TAA-A(5)-NH.sub.2 4282.97 4283.00 ASO5 Fethoc-AAG(6)-TG(6)T-A(5)CC(1O2)-TA(5)A-A-NH.sub.2 4281.98 4282.05 ASO6 Fethoc-AA(5)G-TG(5)T-A(5)CC(1O2)-TA(5)A-A(5)- 4369.06 4369.08 NH.sub.2 ASO7 Fethoc-AA(5)G-TG(5)T-A(5)CC(1O2)-TA(5)A-A(5)C- 4620.16 4620.14 NH.sub.2 ASO8 Fethoc-A(5)GT-G(5)TA(5)-CC(1O2)T-A(5)AA(5)-C- 4345.04 4345.08 NH.sub.2 ASO9 Fethoc-AA(6)G-TG(5)T-A(6)CC(1O2)-TA(6)A-A(6)C- 4676.22 4676.25 NH.sub.2 ASO10 Fethoc-AA(5)G-TG(5)T-A(5)CC(1O2)-TA(5)A-A(5)G- 4660.16 4660.15 NH.sub.2 ASO11 Fethoc-AA(5)G-TG(5)T-A(5)CC(1O2)-TA(5)A- 4895.27 4895.20 A(5)CA-NH.sub.2 ASO12 Fethoc-AA(5)G-TG(5)T-A(5)CC(1O2)-TA(5)A- 4951.27 4951.26 A(5)GG-NH.sub.2 ASO13 Fethoc-AA(5)G-TG(5)T-ACC(1O2)-TA(5)A- 5146.37 5146.35 A(5)CA(5)-C-NH.sub.2 ASO14 Benzoyl-AA(5)G-TG(5)T-A(5)CC(1O2)-TA(5)A- 4488.10 4488.06 A(5)C-NH.sub.2 ASO15 Piv-AA(5)G-TG(5)T-A(5)CC(1O2)-TA(5)A-A(5)C- 4468.13 4468.04 NH.sub.2 ASO16 Fethoc-AA(5)G-TA(5)T-A(5)CC(1O2)-TG(5)A-A(5)C- 4620.16 4620.14 NH.sub.2 ASO17 p-Toluenesulfonyl-AA(5)G-TG(2O3)T-A(5)CC(1O2)- 4682.17 4682.15 TA(5)A-A(5)C-Lys-NH.sub.2 ASO18 n-Hexanoyl-AA(5)G-TG(5)T-A(5)CC(1O2)-TA(8)A- 4524.19 4524.20 A(5)C-NH.sub.2 ASO19 Fethoc-Lys-Leu-AA(5)G-TG(5)T-A(5)CC(1O2)- 4991.41 4991.37 TA(2O2)A-A(5)C-Lys-NH.sub.2 ASO20 [N-(2-Phenylethyl)amino]carbonyl-AA(3)G-TG(5)T- 4545.16 4545.15 A(5)CC(1O5)-TA(5)A-A(5)C-NH.sub.2 ASO21 H-AA(5)G-TG(2O2)T-A(5)CC(1O2)-TA(5)A-A(5)C- 4386.05 4386.03 NH.sub.2 ASO22 n-Propyl-AA(5)G-TG(5)T-A(5)CC(1O3)-TA(5)A- 4440.14 4440.06 A(5)C-NH.sub.2 ASO23 N,N-Phenyl-Me-AA(5)G-TG(5)T-A(5)CC(1O2)- 4460.10 4460.09 TA(5)A-A(4)C-NH.sub.2 ASO24 Benzoyl-AA(5)G-TG(3)T-A(5)CC(2O2)-TA(5)A- 4474.08 4474.11 A(5)C-NH.sub.2 ASO25 p-Toluenesulfonyl-TG(2O3)T-A(5)CC(1O2)-TA(5)A- 4238.92 4238.95 A(3)CA-C-Lys-NH.sub.2 ASO26 Fethoc-AA(5)G-TG(5)T-A(5)AC(1O2)-TA(5)T-A(5)C- 4635.16 4635.14 NH.sub.2 .sup.atheoretical exact mass, .sup.bobserved exact mass
[0251]
Binding Affinity of PNA Derivatives for Complementary DNA
[0252] The PNA derivatives in Table 1 were evaluated for their binding affinity for 10-mer DNAs complementarily targeting either the N-terminal or C-terminal of PNA. The binding affinity was assessed by T.sub.m value for the duplex between PNA and 10-mer complementary DNA. The duplex between PNA derivatives in Table 1 and fully complementary DNAs show T.sub.m values too high to be reliably determined in aqueous buffer solution, since the buffer solution tended to boil during the T.sub.m measurement.
[0253] T.sub.m values were determined on a UV/V is spectrometer as follows. A mixed solution of 4 M PNA oligomer and 4 M complementary 10-mer DNA in 4 mL aqueous buffer (pH 7.16, 10 mM sodium phosphate, 100 mM NaCl) in 15 mL polypropylene falcon tube was incubated at 90 C. for a minute and slowly cooled down to ambient temperature. Then the solution was transferred into a 3 mL quartz UV cuvette equipped with an air-tight cap, and subjected to a T.sub.m measurement on a UV/Visible spectrophotometer at 260 nm as described in the prior art [PCT/KR2009/001256] or with minor modifications. The 10-mer complementary DNAs for T.sub.m measurement were purchased from Bioneer (www.bioneer.com, Dajeon, South Korea) and used without further purification.
[0254] The observed T.sub.m values of the PNA derivatives of Formula I were very high for a complementary binding to 10-mer DNA, and are provided in Table 2 as uncorrected. For example, ASO 7 showed a T.sub.m value of 77.0 C. for the duplex with the 10-mer complementary DNA [i.e. (5.fwdarw.3) AGG-TAC-ACT-T (SEQ ID NO: 9)] targeting the N-terminal 10-mer in the PNA as marked bold and underlined in
TABLE-US-00006 [(N.fwdarw. C)Fethoc-AA(5)G-TG(5)T-A(5)CC(1O2)-TA(5)A- A(5)C-NH.sub.2].
In the meantime, ASO 7 showed a T.sub.m of 69.0 C. for the duplex with the 10-mer complementary DNA [i.e. (5.fwdarw.3) GTT-TAG-GTA-C (SEQ ID NO: 10)] targeting the C-terminal 10-mer in the PNA as marked bold and underlinedin
TABLE-US-00007 [(N.fwdarw. C)Fethoc-AA(5)G-TG(5)T-A(5)CC(1O2)-TA(5)A- A(5)C-NH.sub.2].
TABLE-US-00008 TABLE 2 T.sub.m values between PNAs in Table 1 and 10-mer complementary DNA targeting either the N-terminal or the C-terminal of PNA. T.sub.m Value, C. 10-mer DNA 10-mer DNA PNA against N-Terminal against C-Terminal ASO 2 74.0 65.0 ASO 4 77.0 66.0 ASO 5 78.0 66.0 ASO 6 75.0 72.0 ASO 7 77.0 69.0 ASO 8 78.1 70.0 ASO 10 79.0 74.0
Examples for Biological Activities of PNA Derivatives of Formula I
[0255] PNA derivatives of Formula I were evaluated for in vitro and in vivo biological activities. The biological examples provided below are to illustrate the antisense activity of PNA derivatives of Formula I in cells as well as in animals, and therefore should not be interpreted to limit the scope of the current invention to the compounds listed in Table 1.
Example 1. Exon Skipping Induced by ASO 7 in PC3 Cells (A)
[0256] ASO 7 specified in Table 1 is a 14-mer ASO complementarily binding to a 14-mer sequence of the 3 splice site spanning the junction of intron 3 and exon 4 within the human SCN9A pre-mRNA. The 14-mer target sequence within the 3 splice site is as marked bold and underlined in
TABLE-US-00009 [(5.fwdarw. 3)uuguguuuag| GUACACUUUU(SEQIDNO: 5)].
ASO 7 possesses a 6-mer complementary overlap with intron 3, and an 8-mer complementary overlap with exon 4.
[0257] Since PC3 cells (Cat. Number CRL1435, ATCC) are known to abundantly express the human SCN9A mRNA [Br. J. Pharmacol. vol 156, 420-431 (2009)], ASO 7 was evaluated for its ability to induce the skipping of exon 4 in PC3 cells as follows.
[0258] [Cell Culture & ASO Treatment] PC3 cells grown in 60 mm culture dish containing 5 mL F-12K medium were treated with ASO 7 at 0 (negative control), 1, 10 or 100 zM.
[0259] [RNA Extraction & cDNA Synthesis by One-step PCR] Following an incubation with ASO 7 for 5 hours, total RNA was extracted using Universal RNA Extraction Kit (Cat. Number 9767, Takara) according to the manufacturer's instructions. 200 ng of RNA template was subjected to a 25 L reverse transcription reaction using Super Script One-Step RT-PCR kit with Platinum Taq polymerase (Cat. No. 10928-042, Invitrogen) against a set of exon-specific primers of [exon 2_forward: (5.fwdarw.3) CTTTCTCCTTTCAGTCCTCT (SEQ ID NO: 11); and exon 9_reverse: (5.fwdarw.3) CGTCTGTTGGTAAAGGTTTT (SEQ ID NO: 12)] according to the following cycle conditions: 50 C. for 30 min and 94 C. for 2 min, which was followed by 15 cycles of 30 sec at 94 C., 30 sec at 55 C., and 2 min at 72 C.
[0260] [Nested PCR Amplification] 1 L of cDNA was then subjected to a 20 L nested PCR reaction (Cat. No. K2612, Bioneer) against a set of exon-specific primers of [exon 2n_forward: (5.fwdarw.3) CCACCGGACTGGACCAAAAA (SEQ ID NO: 13); and exon 9n_reverse: (5.fwdarw.3) GCTAAGAAGGC-CCAGCTGAA (SEQ ID NO: 14)] according to the following cycle conditions: 95 C. for 2 min followed by 34 cycles of 30 sec at 95 C., 30 sec at 55 C., and 1 min at 72 C.
[0261] [Identification of Exon Skipping Products] The PCR products were subjected to electrophoretic separation on a 2% agarose gel. The bands of target size were collected and analyzed by Sanger Sequencing.
[0262]
Example 2. Exon Skipping Induced by ASO 7 in PC3 Cells (B)
[0263] ASO 7 was evaluated for its ability to induce the skipping of exon 4 in PC3 cells as in Example 1, unless noted otherwise. In this experiment, PC3 cells were treated with ASO 7 at 0 (negative control), 1, 10, 100 and 1,000 aM for 24 hours. The nested PCR reaction was carried out against a set of primers of [exon 3/6_forward: (5.fwdarw.3) GGACCAAAAATGTCGAGCCT (SEQ ID NO: 15); and exon 9_reverse: (5.fwdarw.3) GCTAAGAAGGCCCAGCTGAA (SEQ ID NO: 14)] designed to amplify the product possessing the junction sequence of exon 3 and exon 6.
[0264] The primer sequence of exon 3/6_forward recognizes the junction of exon 3 and exon 6 more selectively than the junction of exon 3 and exon 4 found in the full length SCN9A mRNA. The primer sequence was designed to detect the SCN9A splice variant lacking exons 4-5 more sensitively than the full length SCN9A mRNA. Such an exon skipping primer would be useful to detect mRNA splice variants with poor metabolic stability, since full-length mRNAs tend to show good metabolic stability gained through the evolution over billions years.
[0265]
Example 3. qPCR for SCN9A mRNA in PC3 Cells Treated with ASO 7 (A)
[0266] ASO 7 was evaluated by SCN9A nested qPCR for its ability to induce changes in the human SCN9A mRNA level in PC3 cells as described below.
[0267] [ASO Treatment] PC3 cells were treated with ASO 7 at 0 (negative control), 0.1, 1 or 10 aM. (2 culture dishes per each ASO concentration) [RNA Extraction & cDNA Synthesis by One-step PCR] Following an incubation with ASO 7 for 24 hours, total RNA was extracted and subjected to one-step PCR amplification as described in Example 1.
[0268] [Nested qPCR Amplification] The cDNA solutions were diluted by 100 times, and 1 L of each diluted PCR product was subjected to a 20 L Real-Time PCR reaction against a set of exon specific primers of [exon 3_forward: (5.fwdarw.3) TGACCATGAATAACCCAC (SEQ ID NO: 16); and exon 4 reverse: (5.fwdarw.3) GCAAGGATTTTTACAAGT (SEQ ID NO: 17)] according to the following cycle conditions: 95 C. for 30 sec followed by 40 cycles 5 sec at 95 C., and 30 sec at 60 C. The qPCR reaction was followed with a TaqMan probe of [(5.fwdarw.3) 5,6-FAM-GGACCAAAA-Zen-ATGTCGAGTACAC-3IABkFQ] (ATGTCGAGTACAC disclosed as SEQ ID NO: 18) targeting the junction of exon 3 and exon 4 within the full-length SCN9A mRNA.
[0269]
Example 4. qPCR for SCN9A mRNA in PC3 Cells Treated with ASO 7 (B)
[0270] ASO 7 was evaluated by SCN9A nested qPCR for its ability to induce changes in the human SCN9A mRNA level in PC3 cells as in Example 3, unless noted otherwise. cDNA was synthesized using random hexamers, and subjected to SCN9A qPCR reaction against the TaqMan probe.
[0271]
Example 5. Induction of Spinal Neuropathy in Rats by L5/L6 Spinal Nerve Ligation
[0272] Spinal nerve ligation (SNL) induces neuropathy in the dorsal root ganglia (DRG) and spinal cord, and has been widely used as a model for neuropathic pains. [Pain vol 50(3), 355-363 (1992)] Depending on how spinal nerve bundle(s) is ligated, however, there are several variations of SNL. The degree and duration of neuropathy in DRG appears to vary depending on how spinal nerve bundle(s) is ligated. [Pain vol 43(2), 205-218 (1990)] According to in-house experience, the dual ligation of the L5 and L6 spinal nerves (i.e., L5/L6 ligation) induces neuropathy more severe and persisting longer than the single ligation of the L5 spinal nerve (i.e. L5 ligation).
[0273] [SNL Surgery by L5/L6 Ligation] Male SD rats were anesthetized with zoletil/rompun. Then the L5 and L6 spinal nerve bundles (left side) were exposed and tightly ligated. Then the muscle and skin were closed and clipped according to due aseptic procedures.
[0274] [Induction of Neuropathic Pain] 6 to 7 days after the SNL operation, the paw of the ligated side was stimulated by von Frey scoring using an electronic von Frey anesthesiometer (Model Number 2390, IITC Inc. Life Science) as described below. Von Frey scoring was done on a daily basis until the grouping for pharmacologic evaluations.
[0275] [Electronic Von Frey Scoring] After stabilization for less than 30 minutes each animal in a plastic cage customized for von Frey scoring, the left hind paw of each animal was subjected to von Frey scoring 6 times with an interval of several minutes between scorings. The score from the first scoring was discarded since the animals were not stabilized during the first scoring. Of the five remaining scores, the highest and lowest scores were excluded. Then the average of the remaining three scores was taken as the von Frey score for the animal.
Example 6. Reversal of Allodynia by ASO 7 in Rats with Spinal Neuropathy. (1)
[0276] ASO 7 is a 14-mer SCN9A ASO partially complementary to the rat SCN9A pre-mRNA read out from the rat genomic DNA [NCBI Reference Sequence: NC_000002.12] with a single mismatch at the 3-end of the target sequence. The target 13-mer sequence of ASO 7 within the rat SCN9A pre-mRNA is specified bold and underlined as marked in the 20-mer SCN9A pre-mRNA sequence of
TABLE-US-00010 [(5.fwdarw. 3)uuuccuuuag| GUACACUUUU(SEQIDNO: 19)],
wherein the single mismatch found in intron 3 was marked with quote sign ( ).
[0277] ASO 7 was evaluated for its ability to reverse the allodynia in rats with spinal neuropathy induced by L5/L6 ligation as described below.
[0278] [SNL Surgery and Grouping] In Day 10, male SD rats (6 weeks old, Harlan Laboratories, Italy) were subjected to L5/L6 ligation. Animals were stimulated by von Frey scoring from Day 4 on a daily basis. In Day 0, 30 animals were selected based on individual von Frey scores in Day 0, and assigned into 4 groups of the negative control group (i.e., no ASO treatment), and the three treatment groups of 1, 3 and 6 pmole/Kg ASO 7. (6 or 9 animals per group)
[0279] [ASO Treatment and Von Frey Scoring] Rats subcutaneously received ASO 7 at 0 (negative control), 1, 3 or 6 pmole/Kg in the afternoon in Days 0, 2, 4, 6, 8 and 10. Allodynia was scored by the electronic von Frey scoring method described in Example 5 in the morning. The ASO was administered as naked oligonucleotide, i.e., as dissolved in PBS.
[0280] [Reversal of Allodynia]
[0281] Although there was no positive control comparator included in this specific evaluation, von Frey scores of 10 to 12 g were frequently observed according to in-house evaluations in rats (with L5/L6 ligation) orally administered with pregabalin at 30 mg/Kg. Thus the efficacy of ASO 7 at 1 to 6 pmole/Kg would be comparable to pregabalin 30 mg/Kg in this specific neuropathic pain model.
Example 7. Reversal of Allodynia by ASO 2 in Rats with Spinal Neuropathy
[0282] ASO 2 specified in Table 1 is a 13-mer ASO fully complementary to the 3 splice site spanning the junction of intron 3 and exon 4 in the human SCN9A pre-mRNA as marked bold and underlined in
TABLE-US-00011 [(5.fwdarw. 3)uuguguuuag| GUACACUUUU(SEQIDNO: 5)].
ASO 2 possesses a 5-mer overlap with intron 3, and an 8-mer overlap with exon 4. The target sequence of ASO 2 is conserved in the rat SCN9A pre-mRNA.
[0283] ASO 2 was evaluated for its ability to reverse the allodynia in rats with spinal neuropathy induced by L5/L6 ligation as described in Example 6, unless noted otherwise.
[0284] [Grouping and ASO Treatment] Male SD rats (5 weeks old, Harlan Laboratories, Italy) were subjected to SNL operation in Day 16. In Day 0, 30 rats selected and assigned into 5 groups of the negative control group (i.e., no ASO treatment), and the four treatment groups of 20 pmole/Kg QD (i.e., daily once), 100 pmole/Kg QD, 500 pmole/Kg QD and 100 pmole/Kg Q2D (i.e., once per every two days) ASO 2. (6 animals per group) The animals were subcutaneously administered with ASO 2 during Days 0 to 13 according to the dosing schedules of QD and Q2D. The ASO was administered as naked oligonucleotide, i.e., as dissolved in PBS.
[0285] [Allodynia Scoring] Allodynia was scored during Days 0 to 14 according to the von Frey method described in Example 5. In Day 7, the right paw (unligated side) was subjected to the von Frey scoring.
[0286] [Reversal of Allodynia]
[0287] In case of the paw of the ligated side, the allodynia was significantly reversed (student's t-test) in Day 1 and afterwards in the animals administered with the ASO at 20 pmole/Kg QD, 100 pmole/Kg Q2D and 500 pmole/Kg QD except for the 100 pmole/Kg QD group. In Day 14, however, the allodynia was also significantly reversed in the 100 pmole/Kg QD.
[0288] In case of the paw of the unligated side, the von Frey scores of the ASO treatment groups in Day 7 were higher than the score of the negative control group. The observed von Frey scores were 15.3 g (negative control), 17.6 g (20 pmole/Kg QD), 19.2 g (100 pmole/Kg QD), 20.1 g (100 pmole/Kg Q2D), and 19.5 g (500 pmole/Kg QD). However, there were no significant differences between the ASO treatment groups and the negative control group.
Example 8. Inhibition of Sodium Current by ASO 7 in Rat LS DRG Cells Activated with L5/L6 Spinal Nerve Ligation
[0289] Cellular sodium current is usually measured by patch clamp. As sodium ions are taken up into cell, the intra-cellular sodium ion level increases. The intra-cellular sodium level can be evaluated using a sodium ion sensitive dye. CoroNa Green is a dye with a sodium ion specific chelator of crown ether type. Upon chelation of a sodium ion, CoroNa Green emits green fluorescence. CoroNa Green has been used to indirectly measure the cellular sodium level. The sodium level measured by CoroNa Green was found to correlate well with the sodium ion current measured by sodium ion patch clamp. [Proc. Natl. Acad. Sci. USA vol 106(38), 16145-16150 (2009)]
[0290] ASO 7 was evaluated for its ability to down-regulate sodium ion current in rat DRG cells using CoroNa Green as follows.
[0291] [Extraction of DRG] In Day 0, male SD rats (6 weeks old, Harlan Laboratories, Italy) were subjected to L5/L6 ligation as described in Example 5. The rats were sporadically subjected to von Frey scoring over a period of 4 weeks. In Day 31, a rat showing a low von Frey score was sacrificed to extract both the left (ligated side) and the right (non-ligated side) L5 DRG. The DRGs were immersed in 0.5 mL PBS immediately after the extraction.
[0292] [Preparation of L5 DRG Neuronal Cells] DRG cells were prepared according to the procedures disclosed in the literature [Methods Mol Biol. vol 846, 179-187 (2012); PLoS One vol 8(4); e60558 (2013)], which is briefly described in series as follows: {circle around (1)} DRG was transferred into an 1.5 mL e-tube containing 0.2 mL 0.125% collagenase (Collagenase Type IV, Cat. No. C5138-100MG, Sigma) in HBSS (Hank's Balanced Salt Solution, Cat. Number 14025-092, Life Technologies), chopped into pieces as small as possible with scissors, and incubated for 20 min in a CO.sub.2 incubator at 37 C. under 5% CO.sub.2 and 95% RH; {circle around (2)} 50 L 0.25% trypsin/EDTA was added to the e-tube, which was kept in the incubator for another 10 min; {circle around (3)} the e-tube was charged with 1 mL complete DMEM medium, and subjected to centrifugal sedimentation at 600 g for 5 min; {circle around (4)} the resulting pellet was suspended in 4 mL Neurobasal-A medium (Neurobasal Medium, Cat. No. 21103-049, Gibco) supplemented with 2B-27 (B-27 Serum-Free Supplement, Cat. No. 17504-044, Gibco), 1penicillin-streptomycin, 1L-glutamine, and 1 mL of the cell suspension was carefully seeded onto a laminin-coated cover glass (Cat. No. GG-25-1.5-laminin, Neuvitro) placed in a 35 mm culture dish; {circle around (5)} one day after the seeding, the dish was carefully charged with another 1 mL fresh Neurobasal-A medium; {circle around (6)} two days after the seeding, the medium was replaced with 2 mL fresh Neurobasal-A medium supplemented with 1 M Ara-C (cytosine -D-arabinofuranoside, Cat. No. C1768-100MG, Sigma) in order to selectively suppress the growth of cells other than DRG neuronal cells; {circle around (7)} four days after the seeding, the medium was replaced again with 2 mL fresh Neurobasal-A medium supplemented with 1 M Ara-C; and {circle around (8)} five or six days after the seeding, DRG neuronal cells were treated with ASO.
[0293] [ASO Treatment & CoroNa Assay] L5 DRG neuronal cells either with L5/L6 ligation or without L5/L6 ligation were treated with ASO 7 at 0 (negative control), 100 or 1,000 zM. 30 hours later, the cells were washed with 2 mL HBSS, and then charged with 2 mL fresh HBSS. Then the cells were treated with 5 M CoroNa Green (Cat. No. C36676, Life Technologies) at 37 C. 30 min later, the cells were washed 2 times with 2 mL HBSS, and charged with 2 mL fresh HBSS. The culture dish was mounted on an Olympus fluorescence microscope (Model BX53, Olympus) equipped with a CCD camera to continuously capture the green fluorescent images of the cells. The cells were acutely treated with 10 mM NaCl, and then the changes in the cellular fluorescent intensity were digitally recorded over a peroid of 300 sec. There were 4 to 5 cells per frame, i.e. per ASO concentration. The fluorescence intensities from each individual cell were traced at a resolution of second. The traces of the intracellular fluorescence intensities from individual cells were averaged using ImageJ program (version 1.50i, NIH), and the average traces are provided in
[0294] [CoroNa Assay Results] In the DRG neuronal cells stimulated with L5/L6 ligation [cf.
[0295] In the DRG neuronal cells without L5/L6 ligation [cf.
[0296] DRG neuronal cells without neuropathic stimulation are known to express various subtypes of VGSC including Na.sub.v1.7, Na.sub.v1.8, Na.sub.v1.2 and so on. The Na.sub.v1.7 subtype shows a limited contribution to the whole sodium current in DRG neuronal cells without stimulation. [Nat Comm. vol 3, Article Number 791: DOI:10.1038/ncomms1795 (2012)] The rat DRG neuronal cells without L5/L6 ligation may simulate such DRG neuronal cells without neuropathy. The observed inhibition of the sodium current in the DRG cells without L5/L6 ligation may reflect solely the contribution of the sodium current from the Na.sub.v1.7 subtype.
[0297] In the meantime, neuronal cells are known to upregulate Na.sub.v1.7 expression in response to persisting neuropathy. [J Biol Chem. vol 279(28), 29341-29350 (2004); J Neurosci. vol 28(26), 6652-6658 (2008)] The rat DRG neuronal cells with L5/L6 ligation may simulate DRG neuronal cells with neuropathy. ASO 7 at both 100 zM and 1 aM inhibited the sodium current by 8085% in the neuronal cells stimulated by L5/L6 ligation. The higher inhibition of the sodium current by ASO 7 in the DRG cells with L5/L6 ligation is consistent with the upregulation of Na.sub.v1.7 in neuronal cells by chronic neuropathy.
[0298] Taken together the findings observed in the rat DRG neuronal cells with and without L5/L6 ligation, ASO 7 is concluded to selectively inhibit the expression of the Na.sub.v1.7 subtype. ASO 7 appears to inhibit the Na.sub.v1.7 expression more potently in neuronal cells with neuropathy than in those cells without neuropathy.
Example 9. Reversal of Allodynia by ASO 1 in Rats with DPNP
[0299] ASO 1 specified in Table 1 is a 16-mer ASO fully complementary to the 3 splice site spanning the junction of intron 3 and exon 4 in the human SCN9A pre-mRNA as marked bold and underlined in the 25-mer SCN9A pre-mRNA sequence of
TABLE-US-00012 [(5.fwdarw. 3)uuguguuuag| GUACACUUUUACUGG(SEQID NO:20)].
ASO 1 possesses a 5-mer overlap with intron 3, and an 11-mer overlap with exon 4. ASO 1 is fully complementary to the rat SCN9A pre-mRNA.
[0300] ASO 1 was evaluated for its ability to reverse the allodynia elicited by diabetic peripheral neuropathic pain (DPNP) in rats.
[0301] [Induction of DPNP and Grouping] In Day 0, streptozotocin dissolved in citrate buffer (pH 6) was intra-peritoneally administered at 60 mg/Kg to male SD rats weighing ca 200 g in order to induce type I diabetes. [J. Ethnopharmacol. vol 72(1-2), 69-76 (2000)] In Day 10, rats with DPNP were randomly assigned into 2 groups of the negative control (vehicle only, PBS) and 100 pmole/Kg ASO 1 and based on the von Frey scores of individual animals in Day 10 using von Frey microfilaments as described below. (N=8 per group)
[0302] [Von Frey Scoring by Up & Down Method] Allodynia was scored with a set of von Frey microfilaments (Touch Test) according to the Up & Down method. [J Neurosci. Methods vol 53(1), 55-63 (1994)]
[0303] [ASO Administration & Allodynia Scoring] ASO 1 was dissolved in PBS and subcutaneously administered to rats in Days 11, 13, 15, 17 and 19. Allodynia was scored 2 hours post dose in Days 11, 13, 15, 17 and 19, and additionally in Days 21 and 23 in order to assess the duration of the therapeutic activity post the final dose.
[0304] [Reversal of Allodynia]
[0305] Nevertheless, ASO 1 showed an onset time of a few hours in the reversal of the allodynia if judged by the the von Frey scores in Day 11.
Example 10. Reversal of Allodynia by ASO 2 and ASO 6 in Rats with DPNP
[0306] ASO 6 is a 13-mer ASO complementarily binding to a 13-mer sequence of the 3 splice site spanning the junction of intron 3 and exon 4 in the human SCN9A pre-mRNA as marked bold and underlined in the 25-mer SCN9A pre-mRNA sequence of
TABLE-US-00013 [(5.fwdarw. 3)uuguguuuag| GUACACUUUUACUGG(SEQID NO:20].
ASO 6 possesses a 5-mer overlap with intron 3, and an 8-mer overlap with exon 4. Although ASO 2 and ASO 6 target the same sequence in the human SCN9A pre-mRNA, ASO 6 is considered to possess stronger affinity for complementary RNA than ASO 2.
[0307] ASO 2 and ASO 6 were evaluated for their ability to reverse the allodynia elicited by DPNP in rats as described in Example 9, unless noted otherwise.
[0308] Diabetes was induced in male SD rats (6 weeks old, Harlan Laboratories, Italy) by an intraperitoneal injection of streptozotocin at 60 mg/Kg in Day -10. In Day 0, 18 animals showing lowest von Frey scores were selected and assigned to three groups of the negative control (vehicle only, PBS), 60 pmole/Kg ASO 2 and 30 pmole/Kg ASO 6. (N=6 per group) Rats were subcutaneously administered with vehicle or ASO dissolved in PBS in Days 0, 2 and 4. Allodynia was scored by the electronic von Frey method as described in Example 5.
[0309] [Reversal of Allodynia]
[0310] In the animals received 60 pmole/Kg ASO 2, the allodynia was gradually reversed to the baseline level without diabetic neuropathy (i.e. full recovery level by in-house historical threshold) in Day 4 post the first dose in Day 0. The therapeutic activity significantly (student's t-test) persisted for another 3 days post the final dose in Day 4.
[0311] In the animals received 30 pmole/Kg ASO 6, the therapeutic activity significantly (student's t-test) picked up in Day 2, and persisted for another 4 days post the final dose in Day 4. Thus, ASO 6 reversed the allodynia more potently than ASO 2. Unlike ASO 1 in Example 9, ASO 6 showed a duration of therapeutic activity sufficiently long to support a dosing schedule of 2 times per week in rats.
[0312] [Miscellaneous] As the diabetes persisted, animals in the negative control group showed signs of physical collapse during von Frey scorings. Animals in the treatment groups were lively and responsive to the von Frey challenge, which would be consistent with the therapeutic activity of the ASOs.
Example 11. Analgesic Activity of ASO 7 in Rat Formalin Test
[0313] Pain induced by an intraplantar injection of 20 L 2% formalin markedly decreased in global SCN9A KO mice. The inhibitory extent was 73% and 86% for Phase I (0 to 10 min post the formalin injection) and Phase II (15 to 45 min post the formalin injection), respectively. [PLoS One vol 9(9), e105895 (September 2014)]
[0314] ASO 7 possesses a single mismatch at the 5-end of the rat SCN9A pre-mRNA, and was evaluated for its analgesic activity in rat formalin test as follows.
[0315] [Grouping and ASO Treatment] In Day -6, 24 male SD rats (6 weeks old, Harlan Laboratories, Italy) were randomly assigned to 4 groups of the negative control (no ASO treatment) and three ASO 7 treatment groups of 10, 30 and 100 pmole/Kg. (N=6 per group)
[0316] Each group of animals subcutaneously received ASO 7 at 0 (negative control), 10, 30 or 100 pmole/Kg in Days 6 and 2. ASO 7 was diluted in PBS for the injection.
[0317] [Formalin Test] In Day 0, acute pain was induced by an intraplantar injection of 50 L 5% formalin in the left hind paw Immediately after the formalin injection, each rat was subjected to individual video recording for an hour post the formalin injection. The video was replayed to visually score the pain responses for each inflicted animal.
[0318] [Analgesic Activity]
Example 12. Analgesic Activity of ASO 10 in Rat Formalin Test
[0319] ASO 10 specified in Table 1 is a 14-mer SCN9A ASO partially complementary to the human SCN9A pre-mRNA with a single mismatch at the 5-end of the target pre-mRNA sequence as marked bold and underlined in the 25-mer SCN9A pre-mRNA sequence of
TABLE-US-00014 [(5.fwdarw. 3)uuguguuuag| GUACACUUUUACUGG(SEQID NO:20)],
wherein the single mismatch in intron 3 is marked with quote sign ( ). In the meantime, ASO 10 is fully complementary to the 3 splice site spanning the junction of intron 3 and exon 4 within the rat SCN9A pre-mRNA as marked bold and underlined in the 20-mer rat SCN9A pre- mRNA sequence of
TABLE-US-00015 [(5.fwdarw. 3)uuuccuuuag| GUACACUUUU(SEQIDNO: 19)].
ASO 10 possesses a 6-mer overlap with intron 3 and an 8-mer overlap with exon 4.
[0320] ASO 10 was evaluated for its analgesic activity in rat formalin test as described in Example 11, unless noted otherwise.
[0321] [Grouping and ASO Treatment] 36 male SD rats (7 weeks old, Harlan Laboratories, Italy) were randomly assigned to four groups of the negative control (no ASO treatment) and three ASO 10 treatment groups of 15, 50 and 150 pmole/Kg. (N=9 per group) Each group of animals were subcutaneously administered with ASO 10 at 0 (negative control), 15, 50 or 150 pmole/Kg in Days -6 and -2. The ASO was administered as dissolved in PBS.
[0322] [Analgesic Activity]
[0323] Interestingly, the 150 pmole/Kg group failed to show therapeutic activity both in Phase I and Phase II. ASO 10 at 150 pmole/Kg would be an overdose inducing an transcription upregulation by the exon intron circular RNA (EIciRNA) accumulated during the exon skipping with ASO 10. [Nature Struc. Mol. Biol. vol 22(3), 256-264 (2015)].
Example 13. Inhibition of Na.SUB.v.1.7 Expression in L5 DRG by ASO 7 in Rats Inflicted with an Intraplantar Formalin Injection
[0324] ASO 7 was evaluated by IHC (immunohistochemistry) for its ability to inhibit the expression of Na.sub.v1.7 in the L5 DRG of male SD rats inflicted with an intraplantar injection of formalin as follows.
[0325] [ASO Treatment and Formalin Injection] In Day 5, male SD rats (6 weeks old, Harlan Laboratories, Italy) were randomly assigned to 4 groups of the negative control (no ASO treatment) and three ASO 7 treatment groups of 1, 6 and 30 pmole/Kg. Each group of animals subcutaneously received ASO 7 at 0 (negative control), 1, 6 or 30 pmole/Kg in Days 5 and 1. ASO 7 was diluted in PBS and used for the injection. In Day 0, all the animals received a single intraplantar injection of 50 L 5% formalin.
[0326] [Extraction of L5 DRG and Na.sub.v1.7 IHC] In Day 8, the rats were anesthetized with zoletil/rompun and subjected to sampling of the L5 DRG of the formalin injected side. (N=2 per group) The DRG samples were subjected to Na.sub.v1.7 IHC as briefly described below.
[0327] The DRG samples were cryo-sectioned and subjected to immunostaining in series with a primary anti-Na.sub.v1.7 antibody (Cat. No. ASC-008, Alomone) at 1:500 dilution, with a secondary anti-IgG (Cat No. BA-1100, Vector) at 1:200 dilution, and then with Dylight 594-steptavidin (Cat No. SA-5594, Vector, Calif., USA) at 1:200 dilution for red fluoresence tagging. IHC images were captured on a Zeiss slide scanner for the Na.sub.v1.7 expression in DRG.
[0328] [Inhibition of Na.sub.v1.7 Expression in L5 DRG]
[0329] The level of red color in each individual IHC image was digitally scored by using NIH ImageJ program, and the individual levels were subjected to statistical analysis by group. (N=2 per group)
Example 14. Reversal of Allodynia in Rats with Spinal Neuropathy by ASO 10 (1)
[0330] ASO 10 was evaluated for its ability to reverse the allodynia in rats with spinal neuropathy induced by L5/L6 ligation as described in Example 6 unless noted otherwise.
[0331] [Grouping] In Day 14, male SD rats (5 weeks old, Harlan Laboratories, Italy) were subjected to L5/L6 ligation. In Day 0, 36 animals were selected based on their individual von Frey scores in Day 0, and assigned to 4 groups of the negative control group (i.e., no ASO treatment), three ASO treatment groups of 1, 3 and 10 pmole/Kg. (N=9 per group)
[0332] [ASO Treatment and Von Frey Scoring] Rats subcutaneously received in the afternoon ASO 10 at 0 (negative control), 3 and 10 pmole/Kg in Days 0, 3 and 7. In the 1 pmole/Kg treatment group, the dose was initially 1 pmole/Kg in Day 0, and then raised to 30 pmole/Kg in Days 3 and 7 due to lack of the therapeutic activity at 1 pmole/Kg in Days 2 and 3.
[0333] [Reversal of Allodynia]
[0334] The allodynia was reversed gradually and significantly over a period of a week by administrations with ASO 10 at 3 to 30 pmole/Kg. The therapeutic activity plateaued out to the von Frey score of ca 13 g for all the treatment groups.
[0335] In the 1 pmole/Kg group, however, the therapeutic activity started picking up after the dose was elevated from 1 pmole/Kg to 30 pmole/Kg in Day 3. The allodynia was significantly reversed by ca 40% in Day 6 after the dose was increased to 30 pmole/Kg, if a historic background threshold of ca 18 g was taken as the von Frey score without L5/L6 ligation. The analgesic efficacy increased to ca 60% in Day 8.
[0336] In the 3 pmole/Kg group, the allodynia was significantly reversed (student's t-test) in Day 6 with a modest (ca 4050%) efficacy. The therapeutic efficacy increased to 65+% in Day 8.
[0337] In the 10 pmole/Kg group, the allodynia was significantly reversed in Day 4 with an efficacy of ca 2530%. The therapeutic efficacy increased to ca 60% in Day 9. However, the efficacy remained stagnant from Day 6.
Example 15. Reversal of Allodynia in Rats with Spinal Neuropathy by ASO 10 (2)
[0338] ASO 10 was evaluated for its ability to reverse the allodynia in rats with spinal neuropathy induced by L5/L6 ligation as described in Example 6 unless noted otherwise.
[0339] [Grouping] In Day -10, male SD rats (6 weeks old, Harlan Laboratories, Italy) were subjected to L5/L6 ligation. In Day 0, 36 animals were selected based on their individual von Frey scores in Day 0, and randomly assigned to 4 groups of the negative control group (i.e., no ASO treatment), two ASO treatment groups of 100 pmole/Kg once per every 4 or 5 days, and the positive control group of pregabalin 30 mg/Kg. (N=9 per group)
[0340] [ASO Treatment and Von Frey Scoring] Rats subcutaneously received in the afternoon ASO 10 at 0 (negative control), 100 pmole/Kg in Days 0 and 4, 100 pmole/Kg in Days 0 and 5. Allodynia was scored in the morning on a daily basis. The rats of the positive control group were orally administered with pregabalin 30 mg/Kg one hour prior to the von Frey scoring. The ASO was administered as dissolved in PBS.
[0341] [Reversal of Allodynia]
[0342] In the ASO treatment group of once per every 4 days, the allodynia was significantly reversed (student's t-test) in all the tested occasions in Days 3, 6 and 7, and significantly superior to pregabalin 30 mg/Kg in Days 3 and 6. Thus the dosing frequency of once per every 4 days in rats appears to be appropriate to maintain the therapeutic activity superior to pregabalin 30 mpk. It is noted that the allodynia was reversed in Day 8 to ca 90% of the basal level without spinal neuropathy against the in-house historical background.
[0343] In the ASO treatment group of once per every 5 days, the allodynia was significantly reversed (student's t-test) in all the tested occasions in Days 3, 6 and 7, and significantly superior to pregabalin 30 mg/Kg only in Days 3. Thus the dosing frequency of once per every 5 days appears to be too long to secure the therapeutic activity significantly superior to pregabalin 30 mg/Kg.
[0344] [Na.sub.v1.7 Expression in Spinal Cord] In Day 7, animals were anesthetized with zoletil/rompun, perfused with PBS supplemented with formalin in order to preserve the structural integrity of the spinal cord, and subjected to sampling of spinal cord. (N=3 per group) Spinal cord samples were processed into paraffin block, and were subjected to IHC in series for Na.sub.v1.7 expression (red staining) with a Na.sub.v1.7 antibody (Cat. No. ASC-008, Alomone) and for neuronal cell body (green staining) with a Neu antibody (Cat. No. Ab104224, Abcam). The nucleus was stained with DAPI (blue).
[0345]
Example 16. Inhibition of Na.SUB.v.1.7 Expression in Rat DRG Neuronal Cells by ASO 10
[0346] ASO 10 was evaluated for its ability to inhibit the expression of Na.sub.v1.7 in rat L5 DRG neuronal cells as described below.
[0347] [Preparation of L5 DRG Neuronal Cells] Male SD rats (7 weeks old, Harlan Laboratories, Italy) were subjected to tight L5/L6 ligation as described in Example 5. 7 days later, 4 rats were anesthetized with zoletil/rompun for the extraction of L5 DRG of the ligated side. The DRGs were pooled and processed in order to prepare DRG neuronal cells as described in Example 8.
[0348] [ASO Treatment] DRG neuronal cells were treated with ASO 10 at 0 (negative control), 10, 100 or 1,000 zM for 24 hours, and then subjected to lysis for western blot against a Na.sub.v1.7 antibody (Cat. No. ab85015, Abcam) probing the C-terminal of the Na.sub.v1.7 protein. -actin was probed for reference. ASO 10 stock solutions were dissolved in DDW and aliquoted to the culture medium.
[0349] [Inhibition of Na.sub.v1.7 Expression]
[0350] ASO 10 is a 14-mer ASO fully complementary to the rat SCN9A pre-mRNA, whilst ASO 7 is a 14-mer ASO fully complementary to the human SCN9A pre-mRNA. The SCN9A inhibitory profiles obtained with ASO 10 in rat neuronal cells can be predictably extrapolated to the SCN9A inhibitory profiles of ASO 7 in human neuronal cells.
Example 17. qPCR for SCN9A mRNA in Rat DRG Neuronal Cells Treated with ASO 10 with cDNA Synthesized by One-Step PCR
[0351] ASO 10 was evaluated by SCN9A nested qPCR for its ability to induce changes in the rat SCN9A mRNA level in rat DRG cells as described below.
[0352] [Preparation of L5 DRG Neuronal Cells] A male SD rat (6 weeks old, Harlan
[0353] Laboratories, Italy) was anesthetized with zoletil/rompun to extract the L5 DRGs. The L5 DRG samples were processed as described in Example 8 in order to prepare L5 DRG neuronal cells.
[0354] [ASO Treatment] Rat L5 DRG neuronal cells were treated with ASO 10 at 0 (negative control), 10, 30, 100 or 300 zM. (1 culture dish per each ASO concentration) ASO 10 stock solutions were dissolved in DDW and aliquoted to the culture medium.
[0355] [RNA Extraction & cDNA Synthesis by One-step PCR] Following an incubation with ASO 10 for 24 hours, total RNA was extracted from cells using Universal RNA Extraction Kit (Cat. Number 9767, Takara) according to the manufacturer's instructions. 200 ng of RNA template was subjected to a 25 L reverse transcription reaction using One Step RT-PCR kit (Invitrogen, USA) against a set of exon specific primers of [exon 2_forward: (5.fwdarw.3) CAATCTTCCG-TTTCAACGCC (SEQ ID NO: 21), and exon 10_reverse: (5.fwdarw.3) ACCACAGCCAGGATCAAGTT (SEQ ID NO: 22)] according to the following cycle conditions: 50 C. for 30 min and 94 C. for 2 min, which was followed by 15 cycles of 30 sec at 94 C., 30 sec at 55 C., and 2 min at 72 C.
[0356] [Nested qPCR Amplification] The cDNA solutions (duplicate per ASO concentration) were diluted by 100 times, and 1 L of each diluted cDNA solution was subjected to a 20 L Real-Time PCR reaction with a TaqMan probe (Cat. No. Rn01514993_mH, ThermoFisher) targeting the junction of exon 3 and exon 4 in the SCN9A pre-mRNA according to the following cycle conditions: 95 C. for 30 sec followed by 40 cycles 5 sec at 95 C., and 30 sec at 60 C.
[0357] The left side figure in
Example 18. qPCR for SCN9A mRNA in Rat DRG Neuronal Cells Treated with ASO 10 with cDNA Synthesis with Random Hexamers
[0358] ASO 10 was evaluated by SCN9A qPCR for its ability to inhibit the expression of the SCN9A mRNA in rat L5 DRG neuronal cells. Total RNA was prepared as described in Example 17, and subjected to cDNA synthesis using random hexamers. The cDNA solutions (duplicate per ASO concentration) were diluted by 100 times, and 1 L, of each diluted PCR product was subjected to a 20 L Real-Time PCR reaction with the TaqMan probe targeting the junction of SCN9A exon 3 and exon 4 according to the following cycle conditions: 95 C. for 30 sec followed by 40 cycles 5 sec at 95 C., and 30 sec at 60 C.
[0359] The cDNA solutions were also subjected to qPCR amplification for the GAPDH mRNA. The Ct values of the SCN9A mRNA were normalized against the Ct values of the GAPDH mRNA.
[0360] The right side figure in
Example 19. Inhibition of Sodium Current in L5 DRG Neuronal Cells by ASO 10 (1)
[0361] ASO 10 was evaluated for its ability to inhibit the sodium current in rat L5 DRG neuronal cells as follows.
[0362] [Preparation of DRG Neuronal Cells] Male SD rats (5 weeks old, Daehan Biolink, South Korea, www.dbl.co.kr) were subjected to tight L5/L6 ligation as described in Example 5. 10 to 14 days after the ligation, rats were anesthetized with zoletil/rompun for the extraction of L5 DRG of the ligated side. L5 DRG neuronal cells were prepared as described below.
[0363] {circle around (1)} L5 DRG acutely extracted from rat was transferred into a 1.5 mL e-tube containing 0.2 mL 0.125% collagenase (Collagenase Type IV, Cat. No. C5138-100MG, Sigma) in HBSS (Hank's Balanced Salt Solution, Cat. Number 14025-092, Life Technologies), chopped into pieces as small as possible with scissors, and then incubated for 20 min in a CO.sub.2 incubator at 37 C. under 5% CO.sub.2 and 95% RH; {circle around (2)} then 50 L 0.25% trypsin/EDTA was added to the e-tube, which was kept in the incubator for another 10 min; {circle around (3)} the e-tube was charged with 1 mL complete DMEM medium, and subjected to centrifugal sedimentation at 600 g for 5 min; {circle around (4)} then the resulting pellet was suspended and transported as sealed in a 15 mL falcon tube containing ca 15 mL Neurobasal-A medium; {circle around (5)} following a transportation of ca an hour, 0.5 mL of the cell suspension was carefully seeded onto a laminin-coated cover glass placed in a well of 24-well plate culture dish; {circle around (6)} the culture plate was incubated in a CO.sub.2 incubator at 37 C. for 2 hours to attach cells onto the cover glass.
[0364] [ASO Treatment] The L5 DRG neuronal cells prepared as above were treated with ASO 10 at 0 (negative control), 10, 30, or 100 zM, and kept in the incubator for 4 hours. The ASO stock solutions were prepared in DDW supplemented with 0.1%(v/v) Tween80. Each stock solution (including vehicle only for the negative control) was aliquoted to the culture medium so as to contain 0.0001%(v/v) Tween80 for patch clamp assays.
[0365] [Manual Patch Clamp Assay] Then the DRG neuronal cells were subjected to sodium current manual patch clamp assays on a sodium patch clamp apparatus (Axopatch 200B Amplifier, Axon Instruments). Patch clamp assays usually took 4 hours. Thus the cells are considered to have been treated with ASO for 4 to 8 hours (i.e., ca 6 hours on average).
[0366] [Data Pooling & Analysis] The above experiment was repeated over several independent occasions in order to increase the statistical power per ASO dose. Only the sodium current data from TTX-sensitive cells was included in the pooling for statistical analysis.
[0367]
Example 20. Inhibition of Sodium Current in L5 DRG Neuronal Cells by ASO 10 (2)
[0368] In-house evaluations of rats from a number of suppliers indicate that the Na.sub.v1.7 expression level in L5 DRG would vary much with age and supplier. ASO 10 was evaluated for its ability to inhibit the sodium current in rat L5 DRG neuronal cells of a different source as described in Example 19, unless noted otherwise.
[0369] [Preparation of DRG Neuronal Cells] Male SD rats (5 weeks old, Harlan Laboratories/Envigo, Denmark) were subjected to tight L5/L6 ligation as described in Example 5. 10 to 14 days after the ligation, rats were anesthetized with zoletil/rompun for the extraction of L5 DRG of the ligated side. L5 DRG neuronal cells were prepared as described below.
[0370] [ASO Treatment] The L5 DRG neuronal cells prepared as above were treated with ASO 10 at 0 (negative control) or 100 zM, and kept in the incubator for 4 hours. The ASO stock solutions were prepared in DDW.
[0371] The sodium current normalized against the cell size significantly (p<0.05) decreased by ca 55% in the cells treated with 100 zM ASO 10 for ca 6 hours on average. (N=14 for the negative control; and N=15 for 100 zM ASO 10) The normalized sodium current for the negative control was higher by 37% in this example than in Example 19. Thus the contribution of Na.sub.v1.7 to the sodium current in DRG neuronal cells should be considerably higher in the rats from the Harlan Laboratories of this example than in the rats from the Daehan Biolink of Example 19.
Example 21. Reversal of Allodynia by ASO 7 in Rats with Spinal Neuropathy. (2)
[0372] ASO 7 was evaluated for its ability to reverse the allodynia in rats with spinal neuropathy induced by L5/L6 ligation as described in Example 6, unless noted otherwise.
[0373] [SNL Surgery and Grouping] In Day 10, male SD rats (5 weeks old, Daehan Biolink, South Korea, www.dbl.co.kr) were subjected to L5/L6 ligation. In Day 0, 48 animals were selected based on the lowest individual von Frey scores in Day 0, and randomly assigned into 6 groups of the negative control group (i.e., no ASO treatment), pregabalin 30 mg/Kg, and the four treatment groups of 5, 25, 125 and 625 fmole/Kg ASO 7. (8 animals per group)
[0374] [ASO Treatment and Von Frey Scoring] Rats subcutaneously received ASO 7 at 0 (negative control), 1, 3 or 6 pmole/Kg in the afternoon in Days 0, 3, 6 and 9. Allodynia was scored by the electronic von Frey scoring method described in Example 5 in the morning. Pregabalin was orally administered one hour prior to each von Fret scoring occasion. The ASO was administered as dissolved in PBS supplemented with 0.1% Tween80.
[0375] [Reversal of Allodynia]
[0376] ASO 7 significantly reversed (student's t-test) the allodynia in Days 2 to 8 at 5 fmole/Kg, in Days 2, 4 and 6 at 25 and 125 fmole/Kg, and in Days 4 and 6 at 625 fmole/Kg. The most active group was the 5 fmole/Kg group, even though there were no significant differences between ASO treatment groups. Pregabalin also significantly reversed the allodynia by 20 to 30% during Days 2 to 8. The most active group was the 5 fmole/Kg group showing a ca 40% reversal of the allodynia, even though there were no significant differences between ASO treatment groups. However, the efficacies of the treatment groups were not significantly different from the efficacy of the pregabalin group.
Example 22. Analgesic Activity of ASO 2 against Sub-chronic Inflammatory Pain in Rats
[0377] ASO 2 was evaluated for its ability to inhibit sub-chronic inflammatory pain in rats inflicted with an intra-plantar injection of Freund's complete adjuvant (FCA) as described below.
[0378] [Induction of Sub-chronic Inflammation] In Day 17, male SD rats (7 weeks old) received an intra-plantar injection of 100 L FCA (Cat. No. F5881-6X10ML, Sigma) in the left hind paw.
[0379] [Scoring of Inflammatory Pain & Grouping] Inflammatory pain in the left hind paw was scored by Randall-Selitto test using an electronic Randall-Selitto apparatus [Model 2390, IITC Life sciences]. Rats were acclimated on a hammock for 10 min prior to pain scoring. (N=5 per group)
[0380] In Day 0, 10 animals stably showing the lowest pain threshold scores over several days were selected for grouping. The 10 animals were assigned to two groups of the negative control group (no ASO treatment) and the treatment group (ASO 2 100 pmole/Kg).
[0381] [ASO Treatment & Pain Assessment] The treatment group animals received ASO 2 at 100 pmole/Kg in the afternoon of Day 0 and in the morning of Day 1. The ASO was dissolved in PBS and subcutaneously administered. Pain was assessed 2 hours post dose in Day 1, and in the morning in Day 4.
[0382] [Analgesic Activity]