COMPOUND FOR REGULATING GENE EDITING EFFICIENCY AND APPLICATION THEREOF
20210207175 ยท 2021-07-08
Assignee
- Shanghai Institute Of Organic Chemistry, Chinese Academy Of Sciences (Shanghai, CN)
- Shanghaitech University (Shanghai, CN)
Inventors
Cpc classification
C12N2310/20
CHEMISTRY; METALLURGY
C12N9/22
CHEMISTRY; METALLURGY
C12N2800/80
CHEMISTRY; METALLURGY
C07D403/06
CHEMISTRY; METALLURGY
C12N15/11
CHEMISTRY; METALLURGY
C07D403/12
CHEMISTRY; METALLURGY
Y02A50/30
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
C07D249/08
CHEMISTRY; METALLURGY
International classification
C12N15/90
CHEMISTRY; METALLURGY
C07D403/12
CHEMISTRY; METALLURGY
C12N15/11
CHEMISTRY; METALLURGY
Abstract
A compound for improving the gene editing specificity and application thereof. Specifically disclosed is a compound represented by formula I or a use of a pharmaceutically acceptable salt thereof. The compound and the pharmaceutically acceptable salt thereof are used for preparing an inhibitor, a composition, or a formulation for inhibiting gene editing and/or improving the gene editing specificity. The structure of the formula I is as stated in the description. The compound can significantly improve the accuracy of CRISPR gene editing, thereby providing a simple and high-efficient policy for accurate gene editing.
Claims
1. A method for inhibiting intracellular gene editing and/or improving the specificity of gene editing, the method comprises: in the presence of a gene editing inhibitor, performing gene editing on cell so as to inhibit gene editing in the cell, wherein the gene editing inhibitor is a compound represented by Formula I, or pharmaceutically acceptable salt, or optical isomer or racemate, or solvate thereof; ##STR00115## wherein, Z.sub.1 is H or -L1-W, wherein L1 is absent or divalent linking group, and the divalent linking group has one or more linking units selected from the group consisting of substituted or unsubstituted C1-C3 alkylene, substituted or unsubstituted NH, substituted or unsubstituted NHNH, O, S, substituted or unsubstituted C3-C6 cycloalkylene, substituted or unsubstituted 3-6 membered heterocyclylene, substituted or unsubstituted C6-C10 arylene, substituted or unsubstituted C3-C10 heteroarylene, or a combination thereof; wherein, the heteroarylene or the heterocyclylene contains 1-3 heteroatoms selected from N, O, S; W is halogen, substituted or unsubstituted C1-C10 alkyl, substituted or unsubstituted C2-C10 alkenyl, substituted or unsubstituted C2-C10 alkenyloxy, substituted or unsubstituted C2-C10 alkynyl, substituted or unsubstituted C2-C10 alkynyloxy, substituted or unsubstituted C3-C10 cycloalkyl, substituted or unsubstituted C1-C10 alkoxy, substituted or unsubstituted C6-C10 aryl, substituted or unsubstituted C3-C10 heteroaryl, substituted or unsubstituted 5-10 membered heterocyclic ring, substituted or unsubstituted 3-10 membered carbocyclic ring (containing 1 to 3 unsaturated bonds); wherein, the heteroaryl or heterocyclic ring contains 1-3 heteroatoms selected from N, O, S; wherein, the substituted means that the H in the group is replaced by one or more substituents selected from the group consisting of halogen, oxo(O), C1-C4 alkyl, C1-C4 haloalkyl, ORa, NRaRb, phenyl, benzyl, C1-C4 alkoxy; wherein the phenyl and benzyl are unsubstituted or have 1-4 substituents selected from the group consisting of halogen, C1-C4 alkyl, C1-C4 haloalkyl, OH, NH2; wherein, Ra and Rb are each independently H, C1-C4 alkyl, or C1-C4 haloalkyl; Z.sub.2 is H, or -L1-W, wherein L1 and W are as defined above; Z.sub.3 is H, or -L1-W, wherein L1 and W are as defined above; Z.sub.4 is H, or -L1-W, wherein L1 and W are as defined above; A is (CO), or SO.sub.2; alternatively, Z.sub.4, A and Z.sub.2 together with the connected carbon atom form a substituted or unsubstituted 5-8 membered ring, and the substituted is as described above; and/or, Z.sub.3 and Z.sub.1 together with the connected carbon atoms form a substituted or unsubstituted 5-8 membered ring; and the definition of the substitution is as described above.
2. The method of claim 1, wherein the compound of Formula I is a compound of Formula A: ##STR00116## wherein, X is ##STR00117## or none; R.sub.1, R.sub.2 and R.sub.3 are each independently selected from the group consisting of H, halogen, C1-C6 alkyl, halogenated C1-C6 alkyl, C1-C6 alkoxy, halogenated C1-C6 alkoxy; R.sub.4 is selected from the group consisting of H, 6-membered aromatic heterocyclic ring containing 1-2 nitrogen atoms; R.sub.5 is selected from the group consisting of amino, substituted or unsubstituted C1-C6 alkoxy, substituted or unsubstituted 6-membered aromatic heterocyclic ring NHNH containing 1-2 nitrogen atoms, substituted or unsubstituted 4-6-membered unsaturated heterocyclic ring containing 1-2 nitrogen atoms; the substituted means substituted by group selected from the group consisting of halogen and oxo.
3. The method of claim 1, wherein the improving gene editing specificity comprises reducing the off-target ratio of gene editing, increasing the ratio of targeted/off-target ratio in gene editing.
4. The method of claim 1, wherein the improving gene editing specificity refers to A2/A11.5, preferably, A2/A12, more preferably, A2/A13, wherein A1 represents the ratio between the number of scheduled gene editing at specific sites to the number of scheduled gene editing at non-specific sites (ie, the number of off-targets) when no compound is added during compounding, A2 represents the ratio between the number of scheduled gene editing at specific sites and the number of scheduled gene editing at non-specific sites when the compound is added.
5. The use method of claim 1, wherein the gene editing comprises gene editing based on homing endonuclease, engineered zinc finger protein, TALE system, CRISPR system (Cas9, c2c2, or cpf1).
6. The method of claim 1, wherein the method is in vitro or in vivo.
7. A reagent product (or reagent combination), comprising: (i) a first agent, which is a gene editing inhibitor, while the inhibitor is a compound represented by Formula I, or pharmaceutically acceptable salt, or optical isomer or racemate, or solvate thereof; ##STR00118## wherein, Z.sub.1 is H or -L1-W, wherein L1 is absent or divalent linking group, and the divalent linking group has one or more linking units selected from the group consisting of substituted or unsubstituted C1-C3 alkylene, substituted or unsubstituted NH, substituted or unsubstituted NHNH, O, S, substituted or unsubstituted C3-C6 cycloalkylene, substituted or unsubstituted 3-6 membered heterocyclylene, substituted or unsubstituted C6-C10 arylene, substituted or unsubstituted C3-C10 heteroarylene, or a combination thereof; wherein, the heteroarylene or the heterocyclylene contains 1-3 heteroatoms selected from N, O, S; W is halogen, substituted or unsubstituted C1-C10 alkyl, substituted or unsubstituted C2-C10 alkenyl, substituted or unsubstituted C2-C10 alkenyloxy, substituted or unsubstituted C2-C10 alkynyl, substituted or unsubstituted C2-C10 alkynyloxy, substituted or unsubstituted C3-C10 cycloalkyl, substituted or unsubstituted C1-C10 alkoxy, substituted or unsubstituted C6-C10 aryl, substituted or unsubstituted C3-C10 heteroaryl, substituted or unsubstituted 5-10 membered heterocyclic ring, substituted or unsubstituted 3-10 membered carbocyclic ring (containing 1 to 3 unsaturated bonds); wherein, the heteroaryl or heterocyclic ring contains 1-3 heteroatoms selected from N, O, S; wherein, the substituted means that the H in the group is replaced by one or more substituents selected from the group consisting of halogen, oxo(O), C1-C4 alkyl, C1-C4 haloalkyl, ORa, NRaRb, phenyl, benzyl, C1-C4 alkoxy; wherein the phenyl and benzyl are unsubstituted or have 1-4 substituents selected from the group consisting of halogen, C1-C4 alkyl, C1-C4 haloalkyl, OH, NH.sub.2; wherein, Ra and Rb are each independently H, C1-C4 alkyl, or C1-C4 haloalkyl; Z.sub.2 is H, or -L1-W, wherein L1 and W are as defined above; Z.sub.3 is H, or -L1-W, wherein L1 and W are as defined above; Z.sub.4 is H, or -L1-W, wherein L1 and W are as defined above; A is (CO), or SO.sub.2; alternatively, Z.sub.4, A and Z.sub.2 together with the connected carbon atom form a substituted or unsubstituted 5-8 membered ring, and the substituted is as described above; and/or, Z.sub.3 and Z.sub.1 together with the connected carbon atoms form a substituted or unsubstituted 5-8 membered ring; and the definition of the substitution is as described above; and (ii) a second reagent, which is a reagent for CRISPR gene editing.
8. The reagent product of claim 7, wherein the gene editing targets disease-causing genes, tumor-related genes, immune-related genes, visual-related genes, auditory-related genes, metabolism-related genes, viruses infection-related genes, and genetic disease-related genes.
9. A kit, comprising: (i) a first container, and a first agent located in the first container, the first agent is a gene editing inhibitor which is a compound represented by Formula I, or pharmaceutically acceptable salt, optical isomer or racemate, or solvate thereof; ##STR00119## wherein Formula I is as defined in claim 1; and (ii) a second container, and a second reagent in the second container, and the second reagent is a reagent for CRISPR gene editing.
10. (canceled)
11. The product of claim 7, wherein the first agent is a compound represented by Formula A, or pharmaceutically acceptable salt, or optical isomer or racemate, or solvate thereof; ##STR00120## wherein, X is or ##STR00121## none; R.sub.1, R.sub.2 and R.sub.3 are each independently selected from the group consisting of H, halogen, C1-C6 alkyl, halogenated C1-C6 alkyl, C1-C6 alkoxy, halogenated C1-C6 alkoxy; R.sub.4 is selected from the group consisting of H, 6-membered aromatic heterocyclic ring containing 1-2 nitrogen atoms; R.sub.5 is selected from the group consisting of amino, substituted or unsubstituted C1-C6 alkoxy, substituted or unsubstituted 6-membered aromatic heterocyclic ring NHNH containing 1-2 nitrogen atoms, substituted or unsubstituted 4-6-membered unsaturated heterocyclic ring containing 1-2 nitrogen atoms; the substituted means substituted by group selected from the group consisting of halogen and oxo.
12. The reagent product of claim 7, wherein the second reagent comprises one or more reagents selected from the group consisting of: (c1) Cas9 nuclease, the coding sequence of Cas9 nuclease, or a vector expressing Cas9 nuclease, or combinations thereof; (c2) gRNA, crRNA, or a vector for generating gRNA or crRNA; and (c3) template for homologous targeted repair: single-stranded nucleotide sequence or plasmid vector.
13. The reagent product of claim 8, wherein the tumor-related genes is an oncogene.
14. The reagent product of claim 8, wherein the immune-related gene is a gene related to autoimmunity.
15. The kit of claim 9, wherein the first agent is a compound represented by Formula A, or pharmaceutically acceptable salt, optical isomer or racemate, or solvate thereof; ##STR00122## wherein, X is ##STR00123## or none; R.sub.1, R.sub.2 and R.sub.3 are each independently selected from the group consisting of H, halogen, C1-C6 alkyl, halogenated C1-C6 alkyl, C1-C6 alkoxy, halogenated C1-C6 alkoxy; R.sub.4 is selected from the group consisting of H, 6-membered aromatic heterocyclic ring containing 1-2 nitrogen atoms; R.sub.5 is selected from the group consisting of amino, substituted or unsubstituted C1-C6 alkoxy, substituted or unsubstituted 6-membered aromatic heterocyclic ring NHNH containing 1-2 nitrogen atoms, substituted or unsubstituted 4-6-membered unsaturated heterocyclic ring containing 1-2 nitrogen atoms; the substituted means substituted by group selected from the group consisting of halogen and oxo.
Description
DESCRIPTION OF FIGURES
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[0096]
[0097]
[0098]
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[0100]
[0101]
DETAILED DESCRIPTION OF INVENTION
[0102] After extensive and in-depth research, the present inventors unexpectedly discovered for the first time that a compound with a structure as shown in Formula I can efficiently inhibit the function of Cas9 protein, thereby significantly improving the gene editing specificity of CRISPR/Cas9 protein. Experiments showed that the compound of Formula I (especially the compound of Formula A) can significantly inhibit CRISPR/Cas9-mediated gene editing, such as gene editing in HEK293 and K562 cells, thus improving the specificity of Cas9. On this basis, the inventor completed the present invention.
Terms
[0103] As used herein, the term improving gene editing specificity means reducing the off-target rate of gene editing, or increasing the N1/NO ratio of gene editing, wherein N1 is the number of scheduled gene editing at specific sites (i.e. on); and NO is the number of scheduled gene editing at non-specific sites (i.e. the number of off-target occurrences, off).
[0104] The term C1-C3 alkylene refers to a linear or branched alkylene group having 1 to 3 carbon atoms, such as methylene, ethylene, propylene, butylene, or the like.
[0105] The term C3-C6 cycloalkylene refers to a divalent cycloalkyl group having 3-6 carbon atoms, such as cyclopropylene, cyclobutylene, cyclopentylene, cyclohexylene.
[0106] The term 3-6 membered heterocyclylene refers to a divalent ring group having 3-6 ring atoms and one or more ring atoms are heteroatoms (selected from the group consisting of N, O, S).
[0107] The term C6-C10 arylene refers to a divalent aryl group having 6-10 carbon atoms, such as a divalent phenyl or a divalent naphthyl.
[0108] The term C3-C10 heteroarylene refers to a divalent heteroaryl group having 3-10 ring atoms and one or more ring atoms are heteroatoms.
[0109] The term C.sub.1-C.sub.10 alkyl refers to a straight or branched chain alkyl group having 1-10 carbon atoms, such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, or the like.
[0110] The term C2-C10 alkenyl refers to a linear or branched alkenyl group having 2-10 carbon atoms, such as vinyl, propenyl, isopropenyl, butenyl, isobutenyl, or the like.
[0111] The term C2-C10 alkenyloxy refers to a straight or branched alkenyloxy group having 2-10 carbon atoms, such as ethyleneoxy, propyleneoxy, isopropenoxy, butenoxy, isobutenoxy, or the like.
[0112] The term C2-C10 alkynyloxy refers to a linear or branched alkynyloxy group having 2-10 carbon atoms, such as ethynyloxy, propynyloxy, isopropynyloxy, butynyloxy, isobutynyloxy, or the like.
[0113] The term C2-C10 alkynyl refers to a straight or branched chain alkynyl group having 2-10 carbon atoms, such as ethynyl, propynyl, isopropynyl, butynyl, isobutynyl, or the like.
[0114] The term C1-C10 alkoxy refers to a straight or branched chain alkyloxy group having 1-10 carbon atoms, such as methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, or the like.
[0115] The term C.sub.3-C.sub.10 cycloalkyl refers to a cycloalkyl group having 3-10 carbon atoms, such as cyclopropyl, cyclobutyl, cyclopentyl, or the like.
[0116] The term 5-10 membered heterocyclic ring refers to a divalent ring group having 5-10 ring atoms and one or more ring atoms are heteroatoms.
[0117] The term 3-10 membered carbocyclic ring (containing 1-3 unsaturated bonds) refers to a divalent cycloalkane group having 3-10 carbon atoms and 1-3 unsaturated bonds (such as alkenyl bonds or alkynyl bonds).
[0118] The term 5-8 membered ring refers to a ring having 5-8 ring atoms, such as
##STR00013##
[0119] The term halogen refers to F, Cl, Br and I. Halo (or halogenated) refers to fluoro, chloro, bromo, and iodo.
[0120] In the compound of Formula I, the various groups can be the specific groups at the corresponding positions in the table compound.
[0121] Gene Editing Inhibitor
[0122] As used herein, compounds of the present invention, compounds of Formula A, and gene editing inhibitors of the present invention are used interchangeably and refer to compound of the structure shown in Formula A, or pharmaceutically acceptable salt thereof, or optical isomer or racemates or solvates thereof. It should be understood that the term also includes mixtures of the aforementioned components.
##STR00014##
[0123] In the formula, the definition of each group is described as above.
[0124] In another preferred embodiment, preferred compound comprises the compound shown in Table 1, or pharmaceutically acceptable salt thereof, or optical isomer or racemate thereof, or solvate thereof.
[0125] In another preferred embodiment, the compound of Formula I is the compound shown in Table 1.
[0126] In the present invention, a pharmaceutically acceptable salt of the compound of Formula A is also included. The term pharmaceutically acceptable salt refers to a salt formed by a compound of the present invention and an acid or a base suitable for use as a medicine. Pharmaceutically acceptable salt comprises inorganic salt and organic salt. A preferred type of salt is a salt formed by a compound of the present invention with an acid. Acid suitable for salt formation including but is not limited to: inorganic acids such as hydrochloric acid, hydrobromic acid, hydrofluoric acid, sulfuric acid, nitric acid, phosphoric acid, or organic acid such as formic acid, acetic acid, propionic acid, oxalic acid, malonic acid, succinic acid, fumaric acid, maleic acid, lactic acid, malic acid, tartaric acid, citric acid, picric acid, mesylate, benzenesulfonic acid, benzene sulfonic acid; and acidic amino acid such as aspartic acid and glutamic acid.
[0127] The compound of Formula A of the present invention can be prepared by methods well known to those skilled in the art in the prior art, and the reaction parameters of each step are not particularly limited.
[0128] As used herein, in the compound of Formula A, if there are chiral carbons, then the chiral carbons can be R, or S, or some mixture of the two.
[0129] Gene Editing
[0130] The compound of the present invention can significantly improve the specificity of gene editing.
[0131] In the present invention, representative gene editing comprises (but not limited to): CRISPR-based gene editing. Typically, CRISPR-based gene editing comprises CRISPR-Cas-based gene editing. Wherein, the Cas comprises Cas9 and the like.
[0132] Base Editing
[0133] Base editing (BEs) is a fourth-generation gene editing technology developed on the basis of CRISPR-Cas9, which can realize base replacement without cleaving DNA to form double-stranded breaks (DSBs), so it may have higher security.
[0134] At present, the main limitations of BE system are as follows: 1) It cannot realize instantaneous regulation in vivo (intracellular); 2) Outside the expected in-window (which may BE 4-8 bases depending on the different BE systems) cleavage, it may causes out-of-window cleavage. The enzyme used for base editing comprises APOBEC1, APOBEC3A and hAPOBEC3A.
[0135] Use
[0136] The combination of the compound of Formula A of the present invention and gene editing reagents can significantly improve the specificity of gene editing, and thus has revolutionary potential in different fields such as therapeutic applications.
[0137] The compound of Formula A of the present invention can be used to improve the specificity of CRISPR-mediated gene editing, and thus can be used to prevent or treat diseases associated with pathogenic genes.
[0138] In one embodiment, the present invention provides a non-therapeutic in vitro small molecule screening method for inhibiting CRISPR-mediated gene editing, comprising CRISPR-mediated gene knock-in and drug screening system.
[0139] The present invention also provides a method of using small molecules to inhibit CRISPR-mediated gene editing, which can be therapeutic or non-therapeutic. Generally, the method includes the step of administering the compound of Formula A of the present invention to a subject in need.
[0140] Preferably, the subject comprises human and non-human mammal (rodent, rabbit, monkey, livestock, dog, cat, etc.).
[0141] Composition and Method of Administration
[0142] The present invention provides a composition for promoting the specificity of CRISPR-mediated gene editing. The composition comprises (but not limited to): pharmaceutical composition, reagent composition for scientific research and the like.
[0143] In the present invention, the composition can be directly used to inhibit gene editing and/or improve gene editing specificity, such as single gene knock-in, double gene knock-in, point mutation, etc.
[0144] The present invention also provides a pharmaceutical composition, which contains a safe and effective amount of the compound of the present invention and a pharmaceutically acceptable carrier or excipient. Such carriers comprise (but not limited to): saline, buffer, dextrose, water, glycerol, ethanol, powder, and combinations thereof. The pharmaceutical preparation should matched with the method of administration.
[0145] Taking the pharmaceutical composition as an example, the composition of the present invention can be prepared in the form of an injection, for example, the composition can be prepared by conventional methods with normal saline or aqueous solutions containing glucose and other adjuvants. Pharmaceutical composition such as tablets and capsules can be prepared by conventional methods. Pharmaceutical composition such as injection, solution, tablet and capsule should be manufactured under sterile conditions. The drug combination of the present invention can also be made into powder for inhalation.
[0146] The pharmaceutical composition of the present invention can be administered to the subjects (such as human and non-human mammal) in need in a conventional manner. Representative administration methods comprise (but not limited to): oral administration, injection, topical administration, etc.
[0147] The Main Advantages of the Present Invention Include:
[0148] (a) A small molecule compound that can significantly inhibit gene editing and/or improve gene editing specificity is provided for the first time. The compound is particularly effective for CRISPRCas9-mediated hPSC gene knock-in editing.
[0149] (b) The present invention provides a simple and efficient strategy for precise gene editing based on the combination of the compound of Formula A and CRISPR-Cas9.
[0150] (c) The compound of the present invention can enter the cell by directly incubating with the cell, thereby affecting the efficiency of gene editing.
[0151] (d) Some of the compounds disclosed in the present invention, such as compound 49, have been tested clinically and proved to be safe for humans.
[0152] The present invention will be further illustrated below with reference to the specific examples. It should be understood that these examples are only to illustrate the invention but not to limit the scope of the invention. The experimental methods without specific conditions in the following examples usually follow conventional conditions, such as Sambrook et al., Molecular Cloning: Laboratory Manual (New York: Cold Spring Harbor Laboratory Press, 1989), or according to the conditions recommended by the manufacturer. Unless indicated otherwise, parts and percentage are calculated by weight.
Example 1. Small Molecule Inhibitor Screening Based on EGFP Reporter
[0153] The EGFP reporter cell line was constructed as shown in
[0154] Without inhibitors, treatment of the EGFP reporter with CRISPR/Cas9 from Streptococcus pyogenes (SpyCas9) usually results in 11% of fluorescent cells. With the presence of small molecule inhibitors, the percentage of fluorescent cells activated by SpyCas9 would decrease. The 50% inhibitory concentration of each compound (IC.sub.50) can be determined by this assay.
[0155] The results are shown in Table 1.
TABLE-US-00001 TABLE 1 Molecular formula No. IC.sub.50(M) CAS No. &MW Structural formula 12 ++ 20426-12-4 C.sub.15H.sub.12O.sub.2 224.26
Example 2. The Activity of Compounds in Inhibiting the Cas9 on Endogenous Genes
[0156] 2.1 Method
[0157] HEK293 cells (10.sup.5 cells/well) were seeded on a 24-well plate. 24 hours after inoculation, cells were transfected with 200 ng AAVS1-AS2 and 200 ng pST-Cas9 plasmid or 200 ng EMX1 and 200 ng pST-Cas9 plasmid in Opti-MEM medium. 6 hours after transfection, DMEM supplemented with 10% FBS and 10 M drug (Compound 49) was used to replace Opti-MEM. The positive control for Cas9 activity was 200 ng AAVS1-AS2 and 200 ng pST-Cas9 plasmid or 200 ng EMX1 and 200 ng pST-Cas9 plasmid without drug. After the gene editing was completed, the cell genomic DNA was extracted, and the gene editing efficiency was tested by the T7E1 method (see Guschin, D. Y. et al. Methods Mol. Biol. 649, 247-256 (2010))).
[0158] 2.2 Result
[0159] The result is shown in
[0160] In the experiment of transfecting cells with EMX1 and pST-Cas9 plasmids, compared with the mock group, the gene modification rate of the no-drug group was 26.5% and 27.9%, while the gene modification rate of the group with Compound 48 was 0%, the gene modification rate of the group with Compound 115 was 1.5%, and the gene modification rate of the group with Compound 49 was 5.6% and 3.8%.
[0161] Therefore, Compounds 49, 115 and 48 can inhibit the gene editing activity of SpyCas9 expressed by the plasmid on multiple genes.
Example 3. Compound 49 Enhances the Specificity of SpyCas9-Based Gene Editing
[0162] 3.1 Method SpyCas9 was lipid transfected into HEK293 cells or nuclear transfected into K562 cells to determine the effect of compound 49 on the specificity of SpyCas9 in multiple cell lines on different genes. The inhibitor was added to the culture 6 hours after transfection. The detection method is the same as in Example 2.
[0163] 3.2 Result
[0164] As shown in
Example 4. Inhibitory Activity of Compound 49 to Staphylococcus aureus Cas9 (SaCas9)
[0165] 4.1 Method
[0166] The method of this example was similar to 2.1, except that pST-Cas9 was replaced with a plasmid containing SaCas9. The detection method was the same as in Example 2.
[0167] 4.2 Result
[0168] As shown in
Example 5. The Inhibitory Activity of Compounds Modified on the Basis of Compound 49 on Gene Editing
[0169] 5.1 Method
[0170] In order to further prove the malleability of the compound, the inventors tested the analogs of Compound 49 (901-905) to determine their effects on gene editing. The method of this example was the same as in Example 2.
[0171] 5.2 Result
[0172] The result was shown in
Example 6. Compound 49 Regulates the Base Editing System
[0173] 6.1 Method
[0174] HEK293T cells (105 cells/well) were seeded on a 24-well plate. 24 hours after inoculation, cells were transfected with 250 ng sgRNA expression plasmid and 500 ng dCas9-DNMT3a-DNMT31 plasmid system in Opti-MEM medium. 6 hours after transfection, DMEM supplemented with 10% FBS and 500 nM drug (Compound 49) was used to replace Opti-MEM. The positive control was DMEM containing 10% FBS with an equal volume of DMSO solvent control instead of Opti-MEM. 48 h after transfection, cell genomic DNA was extracted, and deep sequencing was performed after PCR amplification of the sgRNA targeting sequence.
[0175] 6.2 Result
[0176] The result was shown in
[0177] Specifically, for the C on 5.sup.th site, when sg47 was used, the C.fwdarw.T conversion frequency was reduced from 18% to 9%, of which the decrease rate was 50%.
Example 7. Improvement of Base Editing Specificity by Compound 49
[0178] 7.1 Method
[0179] The method of this example was the same as in Example 6.1.
[0180] 7.2 Result
[0181] The result was shown in
[0182] Specifically, when sgMSSK1-5 was used, the C.fwdarw.T conversion inhibition efficiency was 30% for the C on 5.sup.th site in the window; for the C on 11.sup.th site out-of-window, the C.fwdarw.T conversion inhibition efficiency was 50%. The inhibition rate on 11.sup.th site was greater than on 5.sup.th site.
Example 8. Base Indel Editing of Compound 49
[0183] 8.1 Method
[0184] The method of this example was the same as in Example 6.1.
[0185] 8.2 Result
[0186] The result was shown in
[0187] Specifically, when sg48 was used, the indel frequency was reduced overall without changing the sg48 targeted 20 bp mutation pattern.
[0188] All literatures mentioned in the present application are incorporated by reference herein, as though individually incorporated by reference. Additionally, it should be understood that after reading the above teaching, many variations and modifications may be made by the skilled in the art, and these equivalents also fall within the scope as defined by the appended claims.