Novel Ezrin Inhibitors and Methods of Making and Using
20180148437 ยท 2018-05-31
Inventors
- Milton L. Brown (Brookeville, MD)
- Mikell Paige (Fairfax, VA)
- Jeffrey A. Torestsky (Silver Spring, MD, US)
- Aykut Uren (Rockville, MD)
- George Kosturko (Alexandria, VA, US)
- Gullay Bulut (Washington, DC, US)
Cpc classification
C07D413/12
CHEMISTRY; METALLURGY
C07D209/48
CHEMISTRY; METALLURGY
C07D401/06
CHEMISTRY; METALLURGY
International classification
C07D413/12
CHEMISTRY; METALLURGY
C07D209/48
CHEMISTRY; METALLURGY
C07D401/06
CHEMISTRY; METALLURGY
C07D401/12
CHEMISTRY; METALLURGY
Abstract
The invention encompasses compound and pharmaceutical composition comprising the compound of the following Formula (I): or pharmaceutically acceptable salts or prodrugs thereof, that are useful for inhibiting ezrin protein in a cell or for inhibiting the growh of a cancer cell.
Claims
1. A compound of ##STR00109## or pharmaceutically acceptable salts or prodrugs thereof, wherein E, F and G are optionally independently present; ##STR00110## wherein Y.sub.1, Y.sub.2, Y.sub.3, and Y.sub.4 are each independently N or CZ; wherein Z is H or a C.sub.1 to C.sub.6 linear, branched or cyclic alkyl; M and D are not both hydrogen; D is H, halogen, OH, aryl, aryloxy, NO.sub.2, CN, carboxy, SH, CF.sub.3, C.sub.1 to C.sub.10 alkoxy, NH.sub.2, or NR.sub.13R.sub.14; wherein R.sub.13 and R.sub.14 are each independently H, C.sub.1 to C.sub.15 linear chain or branched chain alkyl; when none of E, F and G are present, M is H, halogen, OH, aryl, aryloxy, NO.sub.2, CN, carboxy, SH, CF.sub.3, C.sub.1 to C.sub.10 alkoxy, NH.sub.2, or NR.sub.13R.sub.14; when at least one of E, F and G are present, M is NH, O, or S; E is a bond, linear, branched or cyclic C.sub.1 to C.sub.10 alkylene, alkene, alkyne, or ether; F is a bond, O, S, ##STR00111## and G is ##STR00112## wherein R.sub.1-R.sub.12 and X.sub.1-X.sub.5 are each independently selected from H, halogen, OH, aryl, aryloxy, NO.sub.2, CN, carboxy, SH, CF.sub.3, C.sub.1 to C.sub.5 alkoxy, C.sub.1 to C.sub.5 alkyl group, NHCONH.sub.2, NHSO.sub.2CH.sub.3, NHNHNH.sub.2, NH.sub.2, or NR.sub.13R.sub.14; with the proviso that when R.sub.3 is OH and ##STR00113## R.sub.2 and R.sub.4 are not both H, OH, or the same halogen.
2.-61. (canceled)
62. A pharmaceutical composition comprising a compound or a pharmaceutically acceptable salt thereof of claim 1 and a pharmaceutically acceptable carrier.
63. A method of inhibiting ezrin protein in a cell comprising administering at least one compound of claim 1.
64. The method of claim 63, wherein the cell is an abnormal cancer cell.
65. A method of inhibiting the growth of a cancer cell comprising administering to the cell an amount of at least one compound of claim 1.
66. The method of claim 65 wherein the cancer cell is selected from the group consisting of a lung cancer cell, a breast cancer cell, a colon cancer cell, a malignant melanoma cell, an ovarian carcinoma cell, a brain tumor cell, a soft tissue sarcoma cell, rhabdomyosarcoma, prostate cancer and pancreas cancerand an osteosarcoma cell.
67. The method of claim 66 wherein the cancer cell is an osteosarcoma cell.
68. The method of claim 67, wherein the osteosarcoma cell is in a subject.
69. A method of reducing the likelihood of cancer metastasis comprising administering to a subject in need of a therapeutically effective amount of at least one compound of claim 1.
70. The method of claim 69 wherein the cancer is selected from the group consisting of lung cancer, breast cancer, colon cancer, malignant melanoma, ovarian carcinoma, brain tumors, soft tissue sarcomas, rhabdomyosarcoma, prostate cancer and pancreas cancer and osteosarcoma.
71. The method of claim 70 wherein the cancer is osteosarcoma.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0077]
[0078]
[0079]
[0080]
[0081]
[0082]
[0083]
[0084]
[0085]
[0086]
[0087]
DETAILED DESCRIPTION OF THE INVENTION
[0088] As used herein and unless otherwise indicated, the term alkyl means a substituted or unsubstituted, saturated, monovalent linear or branched hydrocarbon chain. Examples of alkyl groups include, but are not limited to, C.sub.1 to C.sub.15 linear, branched or cyclic alkyl, such as methyl, ethyl, propyl, isopropyl, cyclopropyl, 2-methyl-1-propyl, 2-methyl-2-propyl, 3-methyl-1-butyl, 2-methyl-3-butyl, 2,2-dimethyl-1-propyl, 2-methyl-1-pentyl, 3-methyl-1-pentyl, 4-methyl-1-pentyl, 2-methyl-2-pentyl, 3-methyl-2-pentyl, 4-methyl-2-pentyl, 2,2-dimethyl-1-butyl, 3,3-dimethyl-1-butyl, 2-ethyl-1-butyl, butyl, isobutyl, sec-butyl, t-butyl, cyclobutyl, pentyl, isopentyl, neopentyl, hexyl, and cyclohexyl and longer alkyl groups, such as heptyl, octyl, nonyl and decyl. An alkyl can be unsubstituted or substituted with one or two suitable substituents.
[0089] As used herein and unless otherwise indicated, the terms alkoxy or alkyloxy means an O-alkyl, wherein alkyl is as defined herein. An alkoxy can be unsubstituted or substituted with one or two suitable substituents. Preferably, the alkyl chain of an alkyloxy is from 1 to 5 carbon atoms in length, referred to herein, for example, as (C.sub.1-C.sub.5)alkoxy. Preferably, the alkyl chain of an alkyloxy is from 1 to 10 carbon atoms in length, referred to herein, for example, as (C.sub.1-C.sub.10)alkoxy.
[0090] As used herein and unless otherwise indicated, the term alkylene means a linear or branched or cyclic saturated divalent hydrocarbon radical. An alkylene can be unsubstituted or substituted with one or two suitable substituents. Examples of alkylene groups include, but are not limited to, C.sub.1 to C.sub.10 linear chain or branched chain alkylene, such as, methylene, ethylene, propylene, isopropylene, cyclopropylene, 2-methylpropylene, 2-methylpropylene, 2-methylbutylene, 3-methylbutylene, 2-methylbutylene, 2,2-dimethylpropylene, 2-methylpentylene, 3-methylpentylene, 4-methylpentylene, 2-methylpentylene, 3-methylpentylene, 4-methylpentylene, 2,2-dimethylbutylene, 3,3-dimethylbutylene, 2-ethylbutylene, butylene, isobutylene, t-butylene, cyclobutylene, pentylene, isopentylene, neopentylene, cyclopentylene, hexylene, 2-methylpentylene, 3-methylpentylene, and cyclohexylene.
[0091] As used herein and unless otherwise indicated, the terms alkene or alkenyl group means a monovalent linear, branched or cyclic hydrocarbon chain having one or more double bonds therein. The double bond of an alkene can be unconjugated or conjugated to another unsaturated group. An alkene can be unsubstituted or substituted with one or two suitable substituents. Suitable alkenes include, but are not limited to (C.sub.2-C.sub.8)alkenyl groups, such as vinyl, allyl, butenyl, pentenyl, hexenyl, butadienyl, pentadienyl, hexadienyl, 2-ethylhexenyl, 2-propyl-2-butenyl, 4-(2-methyl-3-butene)-pentenyl, An alkene can be unsubstituted or substituted with one or two suitable substituents.
[0092] As used herein and unless otherwise indicated, the terms alkyne or alkynyl group means monovalent linear, branched or cyclic hydrocarbon chain having one or more triple bonds therein. The triple bond of an alkynyl group can be unconjugated or conjugated to another unsaturated group. An alkyne can be unsubstituted or substituted with one or two suitable substituents. Suitable alkynes include, but are not limited to, (C.sub.2-C.sub.8)alkynyl groups, such as ethynyl, propynyl, butynyl, pentynyl, hexynyl, methylpropynyl, 4-methyl-1-butynyl, 4-propyl-2-pentynyl, and 4-butyl-2-hexynyl. An alkynyl group can be unsubstituted or substituted with one or two suitable substituents.
[0093] As used herein and unless otherwise indicated, the term aryl means a monocyclic or polycyclic aromatic ring comprising carbon and hydrogen atoms. Examples of suitable aryl groups include, but are not limited to, phenyl, tolyl, anthacenyl, fluorenyl, indenyl, azulenyl, and naphthyl. An aryl group can be unsubstituted or substituted with one or two suitable substituents. Preferably, the aryl group is a monocyclic ring, wherein the ring comprises 6 carbon atoms, referred to herein as (C.sub.6)aryl.
[0094] As used herein and unless otherwise indicated, the term aryloxy means an O-aryl group, wherein aryl is as defined herein. An aryloxy group can be unsubstituted or substituted with one or two suitable substituents. Preferably, the aryl ring of an aryloxy group is a monocyclic ring, wherein the ring comprises 6 carbon atoms, referred to herein as (C.sub.6)aryloxy.
[0095] As used herein and unless otherwise indicated, the term ether means a group of formula alkyl-O-alkyl, alkyl-O-alkynyl, alkyl-O-aryl, alkenyl-O-alkenyl, alkenyl-O-alkynyl, alkenyl-O-aryl, alkynyl-O-alkynyl, alkynyl-O-aryl, aryl-O-aryl, wherein alkyl, alkenyl, alkynyl and aryl are defined herein.
[0096] As used herein and unless otherwise indicated, the term carboxy means a radical of the formula: COOH.
[0097] As used herein and unless otherwise indicated, the term halogen means fluorine, chlorine, bromine, or iodine. Correspondingly, the meaning of the terms halo and Hal encompass fluoro, chloro, bromo, and iodo.
[0098] As used herein and unless otherwise indicated, the terms substituted and a suitable substituent means a group that does not nullify the synthetic or pharmaceutical utility of the compounds of the invention or the intermediates useful for preparing them. Examples of substituted groups or suitable substituents include, but are not limited to: (C.sub.1-C.sub.10)alkyl; (C.sub.1-C.sub.10)alkenyl; (C.sub.1-C.sub.10)alkynyl; (C.sub.6)aryl; (C.sub.3-C.sub.5)heteroaryl; (C.sub.3-C.sub.7)cycloalkyl; (C.sub.1-C.sub.10)alkoxy; (C6)aryloxy; CN; OH; SH, oxo; halo, NO.sub.2, 1'CO.sub.2H; NH.sub.2; NHOH, NH((C.sub.1-C.sub.10)alkyl); NH((C.sub.1-C.sub.10)alkyl).sub.2; NH((C.sub.6)aryl); NHO((C.sub.1-C.sub.10)alkyl); N(O(C.sub.1-C.sub.10)alkyl).sub.2; NH(O(C.sub.6)aryl); S((C.sub.1-C.sub.10)alkyl); S((C.sub.1-C.sub.10)alkyl).sub.2; S((C.sub.6)aryl); (O); C(S), N((C.sub.6)aryl).sub.2; CHO; C(O)((C.sub.1-C.sub.10)alkyl); C(O)((C.sub.6)aryl); CO.sub.2((C.sub.1-C.sub.10)alkyl); and CO.sub.2((C.sub.6)aryl), C(S)((C.sub.1-C.sub.10)alkyl); C(S)((C.sub.6)aryl); SO.sub.2((C.sub.1-C.sub.10)alkyl); SO.sub.2((C.sub.6)aryl), and SO.sub.3H, C(S)O((C.sub.1-C.sub.10)alkyl); C(S)(O)((C.sub.6)aryl). In certain illustrative embodiments, the substituents can be one or more than one suitable groups, such as, but not limited to, F, Cl, Br, OH, azido, SH, alkyl, aryl, heteroalky, alkyoxyl, alkylthiol, amino, hydroxylamino, N-alkylamino, N,N-dialkylamino, N,N-dimethylamino, acyl, alkyloxycarbonyl, sulfonyl, urea, NO.sub.2, triazolyl. One of skill in art can readily choose a suitable substituent based on the stability and pharmacological and synthetic activity of the compound of the invention.
[0099] As used herein and unless otherwise indicated, the term compounds of the invention means, collectively, the compounds of formula I and pharmaceutically acceptable salts thereof as well as compounds depicted herein. The compounds of the invention are identified herein by their chemical structure and/or chemical name. Where a compound is referred to by both a chemical structure and a chemical name, and that chemical structure and chemical name conflict, the chemical structure is determinative of the compound's identity. The compounds of the invention may contain one or more chiral centers and/or double bonds and, therefore, exist as stereoisomers, such as double-bond isomers (i.e., geometric isomers), enantiomers, or diastereomers. According to the invention, the chemical structures depicted herein, and therefore the compounds of the invention, encompass all of the corresponding compound's enantiomers and stereoisomers, that is, both the stereomerically pure form (e.g., geometrically pure, enantiomerically pure, or diastereomerically pure) and enantiomeric and stereoisomeric mixtures. Enantiomeric and stereoisomeric mixtures can be resolved into their component enantiomers or stereoisomers by well known methods, such as chiral-phase gas chromatography, chiral-phase high performance liquid chromatography, crystallizing the compound as a chiral salt complex, or crystallizing the compound in a chiral solvent. Enantiomers and stereoisomers can also be obtained from stereomerically- or enantiomerically-pure intermediates, reagents, and catalysts by well known asymmetric synthetic methods.
[0100] The phrase pharmaceutically acceptable salt(s), as used herein includes but is not limited to salts of acidic or basic groups that may be present in compounds used in the present compositions. Compounds included in the present compositions that are basic in nature are capable of forming a wide variety of salts with various inorganic and organic acids. The acids that may be used to prepare pharmaceutically acceptable acid salts of such basic compounds are those that form non-toxic acid salts, i.e., salts containing pharmacologically acceptable anions including, but not limited to, sulfuric, citric, maleic, acetic, oxalic, hydrochloride, hydrobromide, hydroiodide, nitrate, sulfate, bisulfate, phosphate, acid phosphate, isonicotinate, acetate, lactate. salicylate, citrate, acid citrate, tartrate, oleate, tannate, pantothenate, bitartrate, ascorbate, succinate, maleate, gentisinate, fumarate, gluconate, glucaronate, saccharate, formate, benzoate, glutamate, methanesulfonate, ethanesulfonate, benzenesulfonate, p-toluenesulfonate and pamoate (i.e., 1,1-methylene-bis-(2-hydroxy-3-naphthoate)) salts. Compounds included in the present compositions that include an amino moiety may form pharmaceutically acceptable salts with various amino acids, in addition to the acids mentioned above. Compounds included in the present compositions that are acidic in nature are capable of forming base salts with various pharmacologically acceptable cations. Examples of such salts include alkali metal or alkaline earth metal salts and, particularly, calcium, magnesium, sodium lithium, zinc, potassium, and iron salts.
[0101] As used herein and unless otherwise indicated, the term prodrug means a derivative of a compound that can hydrolyze, oxidize, or otherwise react under biological conditions (in vitro or in vivo) to provide the compound. Examples of prodrugs include, but are not limited to, compounds that comprise biohydrolyzable moieties such as biohydrolyzable amides, biohydrolyzable esters, biohydrolyzable carbamates, biohydrolyzable carbonates, biohydrolyzable ureides, and biohydrolyzable phosphate analogues. Other examples of prodrugs include compounds that comprise ofigonudeotides, peptides, lipids, aliphatic and aromatic groups, or NO, NO.sub.2, ONO, and ONO.sub.2 moieties. Prodrugs can typically be prepared using well known methods, such as those described in Burger's Medicinal Chemistry and Drug Discovery, pp. 172, 178, 949, 982 (Manfred E. Wolff ed., 5th ed. 1995), and Design of Prodrugs (H. Bundgaard ed., Elselvier, N.Y. 1985).
[0102] The term ezrin as used herein is used as it is in the art. It is understood that ezrin is a protein known to be involved in connections of cytoskeletal structures within the cell to the plasma cell membrane. Ezrin is known to have domains in common with talin protein. Ezrin exists in an inactive conformation, in which the membrane and actin binding sites are masked by intramolecular interaction of the N-terminal and the last 100 amino acids of the long carboxy terminal domains. In its active-open confirmation, ezrin functions as a crosslinker between the plasma membrane and the cortical cytoskeleton. Two factors are reported to be involved in this conformational transition, binding of N-terminal domain to the phosphotidylinositol 4,5 biphosphates (PIP.sub.2) and phosphorylation of a conserved threonine at residue 567 (T567) in the F-actin binding site. Several serine/threonine kinases, Rho kinase (ROCK), protein kinase C-alpha (PKC) and MST4, are also important for T567 phosphorylation. In its active form, ezin can interact with membrane proteins either directly or through adaptor proteins. Ezrin binds to adhesion related proteins with single transmembrane domains such as CD43, CD44, CD95, ICAM-1, -2, -3 and PA.2.26 antigen directly through their cytoplasmic tails, which modulates cell motility and cellular morphology. Ezrin binding to adaptor proteins such as EBP50/NHE-RF and E3KARP regulates the activity of ion transporters, endocytosis of plasma membrane proteins and interaction of F-actin to specific plasma membrane domains. In addition to plasma membrane proteins, ezrin associates with cytoplasmic signaling proteins and is involved in several signaling pathways, such as but not limited to Rho and PI3K/Akt pathways. In addition, ezrin may also be involved in the modulation of nuclear processes such as transcription and RNA processing. For example, ezrin may bind to one or more types of Forkhead Box (Fox) proteins, which would suggest that ezrin may also play a role in transcription. Ezrin can also hind to poly-A-binding protein 1 (PABP1), see
[0103] As used herein, inhibiting the function of ezrin can be related to any of these currently known functions of ezrin. Moreover, the term inhibiting, when used in connection with ezrin function, means a reduction in any downstream effect in which ezrin has a role. The inhibition could be due to any aspect of normal ezrin function, such as but not limited to the reduced binding of ezrin to any of its natural binding partners, the inhibition or reduction of the phosphorylation of ezrin, a loss of association of ezrin with any of its adaptor proteins and the like.
[0104] As used herein and unless otherwise indicated, the term subject means mammals and non-mammals. Mammals means any member of the mammalia class including, but not limited to, humans, non-human primates such as chimpanzees and other ape and monkey species; farm animals such as cattle, horses, sheep, goats, and swine; domestic animals such as rabbits, dogs, and cats; laboratory animals including rodents, such as rats, mice, and guinea pigs; and the like. Examples of non-mammals include, but are not limited to, birds, and the like. The term subject does not denote a particular age or sex, and is used herein interchangeably with patient.
[0105] The terms treating or inhibiting when used in connection with an abnormal condition, e.g., cancer, are intended to include preventing, eradicating, reducing the likelihood or preventing the resulting increase of undesired physiological activity associated with a disorder, for example, in the context of the therapeutic or prophylactic methods of the invention. In another embodiment, the term treating or inhibiting includes antagonistic effects, e.g., diminishment of the activity or production of mediators of a disorder, reducing the rate of proliferation of abnormal cells, etc.
[0106] As used herein and unless otherwise indicated, the terms cancer or cancer cell refer to abnormal cell growth or proliferation that may or may not include spontaneous or induced phenotypic changes. As used herein, cancer includes but is not limited to such abnormal conditions as hypertrophy, neoplasia, hyperplasia, benign and malignant cancer. As used herein, the term tumor is a general term that includes hypertrophies, neoplasias, hyperplasias, benign cancers and malignant cancers. Accordingly, certain embodiments of the present invention include but are not limited to treating a hypertrophy, a neoplasia, a hyperplasia, a benign or a malignant cancer in a subject. In additional embodiments, the present invention is directed to preventing or reducing the likelihood of metastasis and/or recurrence of a hypertrophy, a neoplasia, a hyperplasia, a benign or a malignant cancer within a subject comprising administering at least one compound of the present invention to the subject. For example, at least one compound of the present invention may be administered after tumor resection/removal/ablation, etc. to reduce the likelihood of recurrence of the tumor in the subject. In another example, at least one compound of the present invention may be administered to reduce the likelihood of metastasis of the tumor in the subject.
[0107] As used herein and unless otherwise indicated, the phrase therapeutically effective amount of a composition of the invention is measured by the therapeutic effectiveness of a compound of the invention, wherein at least one adverse effect of a disorder is ameliorated or alleviated.
[0108] When administered to a. cell, the compounds of the invention can be optionally administered in isolated form. As used herein, isolated means that the compounds of the invention are separated from other components of either (a) a natural source, such as a plant or cell, preferably bacterial culture, or (b) a synthetic organic chemical reaction mixture. In one embodiment, the compounds of the invention are purified. As used herein, purified means that when isolated, the isolate contains at least about 80% of a compound of the invention by weight of the isolate. In one embodiment, the isolates contain at least about 90%, at least about 95% or at least about 99% of the compound of the invention by weight.
[0109] The invention encompasses compound and pharmaceutical composition comprising the compound of the following Formula (1):
##STR00046##
or pharmaceutically acceptable salts or prodrugs thereof.
[0110] According to one aspect the present invention provides a compound and pharmaceutical compositions comprising the compound of the following Formula (I): or pharmaceutically acceptable salts and prodrugs thereof,
wherein: [0111] E, F and G are optionally independently present;
##STR00047##
[0112] wherein [0113] Y.sub.1, Y.sub.2, Y.sub.3, and Y.sub.4 are each independently N or CZ; wherein Z is H or a C.sub.1 to C.sub.6 linear, branched or cyclic alkyl group; [0114] M and D are not both hydrogen; [0115] D is H, halogen, OH, aryl, aryloxy, NO.sub.2, CN, carboxy, SH, CF.sub.3, C.sub.1 to C.sub.10 alkoxy, NH.sub.2, or NR.sub.13R.sub.14; wherein R.sub.13 and R.sub.14 are each independently H, C.sub.1 to C.sub.15 straight chain or branched chain alkyl; [0116] wherein when none of E, F and G are present, M is H, halogen, OH, aryl, aryloxy, NO.sub.2, CN, carboxy, SH, CF.sub.3, C.sub.1 to C.sub.10 alkoxy, NH.sub.2, or NR.sub.13R.sub.14; [0117] wherein when at least one of E, F and G are present. M is NH, O, or S; [0118] E is a bond, linear, branched or cyclic C.sub.1 to C.sub.10 alkylene, alkene, alkyne, or ether; [0119] F is a bond, O, S.
##STR00048##
and [0120] G is
##STR00049##
[0121] wherein [0122] R.sub.1-R.sub.12 and X.sub.1-X.sub.5 are each independently selected from H, halogen, OH, aryl, aryloxy, NO.sub.2, CN, carboxy, SH, CF.sub.3, C.sub.1 to C.sub.5 alkoxy group, C.sub.1 to C.sub.5 alkyl group, NHCONH.sub.2, NHSO.sub.2CH.sub.3, NHNHNH.sub.2, NH.sub.2, or NR.sub.13R.sub.14; [0123] with the proviso that when R.sub.3 is OH and
##STR00050## [0124] R.sub.2 and R.sub.4 are not both H, OH, or the same halogen.
[0125] According to one embodiment,
##STR00051##
and none of E, F and G are present. In a more specific embodiment, D is hydrogen; and M is NR.sub.13R.sub.14 in the above-described compound.
[0126] According to another embodiment,
##STR00052##
and none of E, F and G are present;
[0127] wherein at least one of M or D is NH.sub.2 or NR.sub.13R.sub.14.
[0128] In other embodiments,
##STR00053##
and E, F and G are all present;
[0129] wherein M is NH. In a more specific embodiment, D is H, E is a C.sub.1 to C.sub.5 linear alkylene, F is a bond, and G is
##STR00054##
[0130] In other embodiments,
##STR00055##
and E is (CH.sub.2).sub.2, [0131] F is bond, and [0132] G is
##STR00056##
[0133] wherein R.sub.3 is hydroxy or methoxy.
[0134] In other embodiments,
##STR00057##
and E, F and G are all present;
[0135] wherein F is a bond; and G is
##STR00058##
[0136] In other embodiments,
##STR00059##
and E, F and G are all present.
[0137] In other embodiments,
##STR00060##
none of E, F, and G are present. In a more specific embodiment. M is a C.sub.1 to C.sub.10 alkoxy; and D is NH.sub.2in the above-described compound.
[0138] In other embodiments,
##STR00061##
none of E, F, G are present, and M is methoxy.
[0139] In one specific embodiment,
##STR00062##
E is a C.sub.1 to C linear, branched or substitute alkylene; [0140] F is a bond; and [0141] G is
##STR00063##
[0142] In another specific embodiment,
##STR00064##
and [0143] E is (CH.sub.2).sub.2; [0144] F is a bond; [0145] G is
##STR00065##
[0146] wherein X.sub.2 hydroxy, fluorine, methoxy or methyl.
[0147] In another embodiment,
##STR00066##
E is a C.sub.1 to C.sub.5 linear alkylene; [0148] F is
##STR00067##
G is
[0149] ##STR00068##
[0150] wherein R.sub.9 is NH.sub.2, N(CH.sub.3).sub.2, or NR.sub.13R.sub.14.
[0151] In specific embodiments,
##STR00069##
E is a C.sub.1 to C.sub.5 linear alkylene; [0152] F is
##STR00070##
and [0153] G is
##STR00071##
[0154] wherein R.sub.9 is NH.sub.2 or NR.sub.13R.sub.14.
[0155] In other embodiments,
##STR00072##
E is a C.sub.1 to C.sub.5 linear alkylene; [0156] F is
##STR00073##
and [0157] G is
##STR00074##
[0158] wherein D is hydrogen and R.sub.9 is N(CH.sub.3).sub.2.
[0159] In other embodiments,
##STR00075##
E is (CH.sub.2).sub.2, [0160] F is
##STR00076##
and [0161] G is
##STR00077##
[0162] wherein R.sub.9 is NH.sub.2, N(CH.sub.3).sub.2, or NR.sub.13R.sub.14.
[0163] In other embodiments,
##STR00078##
E is (CH.sub.2).sub.2, or C.sub.1 to C.sub.5 linear alkylene; [0164] F is a bond; and [0165] G is
##STR00079##
[0166] wherein R.sub.3 is hydroxy or methoxy.
[0167] In other embodiments,
##STR00080##
and none of E, F and G are present.
[0168] In other embodiments,
##STR00081##
E is (CH.sub.2).sub.2, or C.sub.1 to C.sub.6 linear, branched, or cyclic alkylene; [0169] F is a bond; and [0170] G is
##STR00082##
[0171] wherein R.sup.3 is hydroxy or methoxy.
[0172] According to one embodiment,
##STR00083##
E is (CH.sub.2).sub.2, or C.sub.1 to C.sub.6 linear, branched, or cyclic alkylene; [0173] F is a bond; and [0174] G is
##STR00084##
[0175] wherein D is hydrogen; M is NH; R.sub.1 and R.sub.5 are both hydrogen; R.sub.3 is hydroxy or methoxy.
[0176] Specific embodiments of the invention encompass but are not limited to:
##STR00085## ##STR00086## ##STR00087## ##STR00088## ##STR00089## ##STR00090##
[0177] It will be understood that above compounds are illustrative only and not intended to limit the scope of the claims to only those compounds.
[0178] The compounds of the invention can he synthesized by organic chemistry techniques known to those of ordinary skill in the art.
[0179] In accordance with the invention, a composition comprising a compound of the invention or a pharmaceutically acceptable salt, is administered to a cell, such as lung cell, a breast cancer cell, a lung cancer cell, a malignant melanoma cell, an ovarian carcinoma cell, a brain tumor cell, a soil tissue sarcoma cell, and an osteosarcoma cell.
[0180] The invention also encompasses method of inhibiting the growth of a cancer cell, such as lung cancer cell, a breast cancer cell, a colon cancer cell, a malignant melanoma cell, an ovarian carcinoma cell, a brain tumor cell, a soft tissue sarcoma cell, a rhabdomyosarcoma cell, a pancreatic cancer cell, a prostate cancer cell and an osteosarcoma cell, which comprises administering to the cell a pharmaceutically effective amount of a composition comprising a compound of Formula I, or a pharmaceutically acceptable salt or prodrug thereof.
[0181] The invention also encompasses a method of reducing the likelihood of cancer metastasis, such as lung cancer metastasis, breast cancer metastasis, colon cancer metastasis, malignant melanoma metastasis, ovarian carcinoma metastasis, brain tumor metastasis, soft tissue sarcoma metastasis, rhabdomyosarcoma metastasis, pancreatic cancer metastasis, prostate cancer metastasis and osteosarcoma metastasis, which comprises administering to a subject in need of such treatment a therapeutically effective amount of a composition comprising a compound of Formula I, or a pharamaceutically acceptable salt or prodrug thereof.
[0182] In one embodiment, treatment or treating refers to an amelioration of a. disease or disorder, or at least one detectable symptom thereof. In another embodiment, treatment or treating refers to an amelioration of at least one measurable physical parameter, not necessarily discernible by the patient. In yet another embodiment, treatment or treating refers to inhibiting the progression of a disease or disorder, either physically, e.g., stabilization of a discernible symptom, physiologically, e.g., stabilization of a physical parameter, or both. In yet another embodiment, treatment or treating refers to delaying the onset of a disease or disorder.
[0183] In certain embodiments, the compositions of the invention are administered to a patient, for example a human, as a preventative measure against diseases, including preventing the occurrence of a tumor or preventing the progression of a tumor.
[0184] As used herein, the term prevent, as it relates to tumors and/or abnormal cell growth, indicates that a compound of the present invention is administered to a subject to at least partially inhibit the or reduce the likelihood of growth, division, spread, or proliferation of tumor cells. Of course, the term prevent also encompasses prohibiting entirely the emergence of new tumors or any of the associated symptoms from detectably appearing. Thus a subject may be pretreated, by administering the one or more compounds of the present invention to prevent tumors from arising. The phrase preventing the progression, as it relates to tumors, is used to mean a procedure designed to at least partially inhibit the detectable appearance of one or more additional tumors or aberrant cell growth in a patient already exhibiting one or more symptoms of the presence of a tumor or aberrant cell growth, and is also used to mean at least partially prohibiting the already-present symptoms of cancer from worsening in the subject.
[0185] As used herein, the term administer and administering are used to mean introducing at least one compound or composition into a subject. When administration is for the purpose of treatment, the substance is provided at, or after the diagnosis of an abnormal cell growth, such as a tumor. The therapeutic administration of this substance serves to inhibit cell growth of the tumor or abnormal cell growth.
[0186] As used herein, the term coadminister is used to mean that each of at least two compounds are administered during a time frame wherein the respective periods of biological activity overlap. Thus the term includes sequential as well as coextensive administration of the compositions of the present invention. If more than one substance is coadministered, the routes of administration of the two or more substances need not be the same. The scope of the invention is not limited by the identity of the substance which may be coadministered with the compositions of the present invention. For example, one of the compounds of the present invention may be co-administered with another compound of the present invention or another other pharmaceutically active substances, such as vinca alkaloids, nucleic acid inhibitors, platinum agents, interleukin-2, interferons, alkylating agents, antimetabolites, corticosteroids, DNA intercalating agents, anthracyclines, and ureas. Examples of specific agents in addition to those exemplified herein, include hydroxyurea, 5-fluorouracil, anthramycin, asparaginase, bleomycin, dactinomycin, dacabazine, cytarabine, busulfan, thiotepa, lomustine, mechlorehamine, cyclophosphamide, melphalan, mechlorethamine, chlorambucil, carmustine, 6-thioguanine, methotrexate, etc.
[0187] Due to the activity of the compounds of the invention, the compounds are advantageously useful in yeterinary and human medicine. As described above, the compounds of the invention are useful for the treatment or prevention of conditions caused by uncontrolled cell growth, hyperproliferation of cells, tumor growth, and cancers, for example, lung cancer, pancreatic cancer, leukemia, breast cancer, liver cancer, kidney cancer, human glioblastoma and prostate cancer.
[0188] The invention provides methods of treatment and prophylaxis by administration to a subject of a therapeutically effective amount of a composition comprising a compound of the invention. The subject can be a mammal, including, but is not limited to, an animal such a cow, horse, sheep, pig, chicken, cat, dog, mouse, rat, rabbit, guinea pig, non-human primate or human.
[0189] The present compositions, which comprise one or more compounds of the invention can be administered intravenously, intravenously intramuscularly intraperitonealy and orally.
[0190] Suitable dosage ranges of the compounds of the invention, regardless of the route of administration, are generally about 0.0001 milligram to 2000 milligrams of a compound of the invention per kilogram body weight. In one specific embodiment, the dose is about 0.001 milligram to about 1500 milligrams per kilogram body weight, more specifically about 0.01 milligram to about 1000 milligrams per kilogram body weight, more specifically about 0.1 milligram to about 500 milligrams per kilogram body weight, and yet more specifically about 1 milligram to about 100 milligrams per kilogram body weight.
[0191] The compounds and the compositions of the invention may also be administered by any other route, for example, by infusion or bolus injection, by absorption through epithelial or mucocutaneous linings (e.g., oral mucosa, rectal and intestinal mucosa, etc.), and they may be administered together with another biologically active agent. Administration can be systemic or local. Various delivery systems are known, e.g., encapsulation in liposomes, microparticles, microcapsules, capsules, etc., and can be used to administer a compound or composition of the invention. In certain embodiments, more than one compound of the invention is administered to a patient. Methods of administration include but are not limited to intradermal, intramuscular, intraperitoneal, intravenous, subcutaneous, intranasal, epidural, oral, sublingual, intranasal, intracerebral, intravaginal, transdermal, rectally, by inhalation, or topically. The preferred mode of administration is left to the discretion of the practitioner, and will depend in-part upon the site of the medical condition.
[0192] In specific embodiments, it may be desirable to administer one or more compounds or compositions of the invention locally to the area in need of treatment. This may be achieved, for example, and not by way of limitation, by local infusion during surgery, topical application, e.g., in conjunction with a wound dressing after surgery, by injection, by means of a catheter, by means of a suppository, or by means of an implant, said implant being of a porous, non-porous, or gelatinous material, including membranes, such as but not limited to silastic membranes, or fibers. In one embodiment, administration can be by direct injection at the site (or former site) of an atherosclerotic plaque tissue.
[0193] Pulmonary administration can also be employed, e.g., by use of an inhaler or nebulizer, and formulation with an aerosolizing agent, or via, perfusion in a fluorocarbon or synthetic pulmonary surfactant. in certain embodiments, the compounds of the invention can be formulated as a suppository, with traditional binders and vehicles such as triglycerides.
[0194] The present compositions will contain a therapeutically effective amount of a compound of the invention, optionally more than one compound of the invention, preferably in purified form, together with a suitable amount of a pharmaceutically acceptable vehicle so as to provide the form for proper administration to the patient.
[0195] In a specific embodiment, the term pharmaceutically acceptable means approved by a regulatory agency of the Federal or a state government or listed in the U.S. Phartnacopeia or other generally recognized pharmacopeia for use in animals, and more particularly in humans. The term vehicle refers to a diluent, adjuvant, excipient, or carrier with which a compound of the invention is administered. Such pharmaceutical vehicles can be liquids, such as water and oils, including those of petroleum, animal, vegetable or synthetic origin, such as peanut oil, soybean oil, mineral oil, sesame oil and the like. The pharmaceutical vehicles can be saline, gum acacia, gelatin, starch paste, talc, keratin, colloidal silica, urea, and the like. In addition, auxiliary, stabilizing, thickening, lubricating and coloring agents may be used. When administered to a patient, the compounds of the invention and pharmaceutically acceptable vehicles are preferably sterile. Water is a preferred vehicle when the compound of the invention is administered intravenously. Saline solutions and aqueous dextrose and glycerol solutions can also be employed as liquid vehicles, particularly for injectable solutions. Suitable pharmaceutical vehicles also include excipients such as starch, glucose, lactose, sucrose, gelatin, malt, rice, flour, chalk, silica gel, sodium stearate, glycerol monostearate, talc, sodium chloride, dried skim milk, glycerol, propylene, glycol, water, ethanol and the like. The present compositions, if desired, can also contain minor amounts of wetting or emulsifying agents, or pH buffering agents.
[0196] The present compositions can take the form of solutions, suspensions, emulsion, tablets, pills, pellets, capsules, capsules containing liquids, powders, sustained-release formulations, suppositories, emulsions, aerosols, sprays, suspensions, or any other form suitable for use.
[0197] In another embodiment, the compounds and/or compositions of the invention are formulated in accordance with routine procedures as a pharmaceutical composition adapted for intravenous administration to human beings. Typically, compounds and/or compositions of the invention for intravenous administration are solutions in sterile isotonic aqueous buffer. Where necessary, the compositions may also include a solubilizing agent. Compositions for intravenous administration may optionally include a local anesthetic such as lignocaine to ease pain at the site of the injection. Generally, the ingredients are supplied either separately or mixed together in unit dosage form, for example, as a dry lyophilized powder or water free concentrate in a hermetically sealed container such as an ampoule or sachette indicating the quantity of active agent. Where the compound of the invention is to be administered by infusion, it can be dispensed, for example, with an infusion bottle containing sterile pharmaceutical grade water or saline. Where the compound of the invention is administered by injection, an ampoule of sterile water for injection or saline can be provided so that the ingredients may be mixed prior to administration.
[0198] In one specific embodiment, the compositions of the invention can be administered orally. Formulations for oral delivery may be in the form of tablets, lozenges, aqueous or oily suspensions, granules, powders, emulsions, capsules, syrups, or elixirs, for example. Orally administered compositions may contain one or more optionally agents, for example, sweetening agents such as fructose, aspartame or saccharin; flavoring agents such as peppermint, oil of wintergreen, or cherry; coloring agents; and preserving agents, to provide a pharmaceutically palatable preparation. Moreover, where in tablet or pill form, the compositions may be coated to delay disintegration and absorption in the gastrointestinal tract thereby providing a sustained action over an extended period of time. Selectively permeable membranes surrounding an osmotically active driving compound are also suitable for orally administered compounds of the invention. In one particular platform, fluid from the environment surrounding the capsule is imbibed by the driving compound, which swells to displace the agent or agent composition through an aperture. These delivery platforms can provide an essentially zero order delivery profile as opposed to the spiked profiles of immediate release formulations. A time delay material such as glycerol monostearate or glycerol stearate may also be used. Oral compositions can include standard vehicles such as mannitol, lactose, starch, magnesium stearate, sodium saccharine, cellulose, magnesium carbonate, etc. Such vehicles are preferably of pharmaceutical grade.
[0199] The amount of a compound of the invention that will be effective in the treatment of a particular disorder or condition disclosed herein will depend on the nature of the disorder or condition, and can be determined by standard clinical techniques. In addition, in vitro or in vivo assays may optionally be employed to help identify optimal dosage ranges. The precise dose to be employed in the compositions will also depend on the route of administration, and the seriousness of the disease or disorder, and should be decided according to the judgment of the practitioner and each patient's circumstances. In specific embodiments of the invention, the oral dose of at least one compound of the present invention is about 0.01 milligram to about 100 milligrams per kilogram body weight, or from about 0.1 milligram to about 50 milligrams per kilogram body weight, or from about 0.5 milligram to about 20 milligrams per kilogram body weight, or from about 1 milligram to about 10 milligrams per kilogram body weight.
[0200] Suitable dosage ranges for parenteral, for example, intravenous (i.v.) administration are 0.01 milligram to 100 milligrams per kilogram body weight, 0.1 milligram to 35 milligrams per kilogram body weight, and 1 milligram to 10 milligrams per kilogram body weight. Suitable dosage ranges for intranasal administration are generally about 0.01 pg/kg body weight to 1 mg/kg body weight. Suppositories generally contain 0.01 milligram to 50 milligrams of a compound of the invention per kilogram body weight and comprise active ingredient in the range of 0.5% to 10% by weight. Recommended dosages for intradermal, intramuscular, intraperitoneal, subcutaneous, epidural, sublingual, intracerebral, intravaginal, transdermal administration or administration by inhalation are in the range of 0.001 milligram to 200 milligrams per kilogram of body weight. Suitable doses of the compounds of the invention for topical administration are in the range of 0.001 milligram to 1 milligram, depending on the area to which the compound is administered. Effective doses may be extrapolated from dose-response curves derived from in vitro or animal model test systems. Such inial models and systems are well known in the art.
[0201] In other embodiments, a composition of the invention for parenteral, for example, intravenous administration includes about 0.001 milligram to about 2000 milligrams of a compound of the invention, more preferably about 0.01 milligram to about 1000 milligrams of a compound of the invention, more preferably about 0.1 milligram to about 500 milligrams of a compound of the invention, and yet more preferably about 1 milligram to about 200 milligrams of a compound of the invention.
[0202] The invention also provides pharmaceutical packs or kits comprising one or more containers filled with one or more compounds of the invention, Optionally associated with such container(s) can be a notice in the form prescribed by a governmental agency regulating the manufacture, use or sale of pharmaceuticals or biological products, which notice reflects approval by the agency of manufacture, use or sale for human administration. In a certain embodiment, the kit contains more than one compound of the invention.
[0203] The compounds of the invention can be assayed in vitro and in vivo, for the desired therapeutic or prophylactic activity, prior to use in humans. For example, in vitro assays can be used to determine whether administration of a specific compound of the invention or a combination of compounds of the invention can be used for treating a particular disorder or condition disclosed herein. The compounds of the invention may also be demonstrated to be effective and safe using animal model systems.
[0204] Other methods will be known to the skilled artisan and are within the scope of the invention.
EXAMPLES
[0205] The compounds of the invention showed pharmacological efficacy in treating or preventing various disorders. Example 1
I. Synthetic Procedure for Novel 6- or 7- Substituted aza- or diazanaphthalene-5.8-dione Scaffolds as Anti-Metastatic Agents Targeting osteosarcoma.
[0206] The novel 6- or 7- substituted aza- or diazanaphthalene-5.8-dione scaffolds were synthesized by the route illustrated in scheme 1. Condensation of the primary amine with the dione gives a mixture of 6- or 7-substituted adduct, which can be separated by silica gel chromatography.
##STR00091##
[0207] The starting material in the reaction above can be synthesized using the well-known Henry Reaction, as disclosed in PCT Application No. PCT/US2003/026300 (Publication No. WO 2004/026305), which is incorporated by reference, as shown in Scheme 1a, below. Compounds 4 and 5 below were transformed to compounds 6 and 7 using the Henry reaction, and compounds 6 and 7 were transformed to compounds 8 and 9 using the reactions as disclosed in Kita, Y., et al., J. Org. Chem. 61:223-227 (1996), which is incorporated by reference.
##STR00092##
[0208] The precursor 5.8-dione derivatives for the synthesis of the claimed compounds were generated using methods described in the literature as discussed herein.
[0209] (A) isoquinoline 5,8-dione precursor (Y1, Y3 and Y4=C, Y2=N) used in the methods of the present invention were prepared according to the following reaction scheme 2. The detailed procedure is described in (i) Tett. Lett., 32, 4872-4873, and (ii) Bioorganic and Medicinal chemistry Letter, 17, 6091.
##STR00093##
[0210] (B) Diazanaphthalene-5,8-diones precursor (Y2 and Y4=C, Y1 and Y3=N) used in the process of the present invention were prepared according to the following reaction scheme 3.
##STR00094##
(C) Phthalazine-5,8-dione precursors (Y1 and Y4=C, Y2 and Y3=N) used in the process of the present invention were prepared according to the following reaction scheme 4. The detailed procedure is described in (i) J. Med Chem., 48, 744-752, and (ii) Bioorganic and Medical Chemistry Letters, 27, 2577-2580.
##STR00095##
II. Synthetic Procedure for Novel phthalimide Analogs as Anti-Metastatic Agents Targeting osteosarcoma.
[0211] Syntheses of the phthalimide analogs were accomplished by condensation of the primary amine with the requisite phthalic anhydride in acetic acid under microwave conditions for 1 hour. The isolated adduct was then purified by silica gel chromatography to give the product.
##STR00096##
[0212] (A) The condensation of phthalic anhydride (Y.sub.1=N, Y.sub.2, Y.sub.3 and Y.sub.4=C) and the primary amine (R.sub.1 and R.sub.3=H, and R.sub.2=OH, and n=2) of the above-described reaction is described in scheme 6.
##STR00097##
[0213] (B) The condensation of phthalic anhydride (Y.sub.2=N, Y.sub.1, Y.sub.3 and Y.sub.4=C) and the primary amine (R.sub.1 and R.sub.3=H, and R.sub.2=OH, and n=2) of the above-described reaction is described in scheme 7.
##STR00098##
III. Synthetic Procedure of Novel Substituted Serotonin Scaffolds Anti-Metastatic Agents Targeting osteosarcoma.
[0214] Synthesis of the analogs incorporating the serotonin core can be accomplished by condensation of the requisite tryptamine analog with the corresponding dione to give both the 6- and 7-substituted adducts. The mixture was separated by silica gel chromatography to give each analog.
##STR00099##
[0215] Synthesis of the precursor tryptamine analogs were accomplished according to the following reaction scheme 9. The detailed procedure is described in (i) J. Med. Chem., 22, 63-69, and (ii) J. Fluorine Chemistry, 97, 161-164.
##STR00100## ##STR00101##
IV. Synthetic Procedure of Novel 3,4,5-trisubstituted benzylamino and benzamide Scaffolds.
[0216] 3,4,5-trisubstituted benzylamino and benzamido scaffolds used in the process of the present invention were prepared according to the following reaction scheme 10. The detailed procedure is described in (i) U.S. Pat. No. 5,283,336 and (ii) J. Med. Chem., 50, 3497.
##STR00102##
V. Synthetic Procedure of Chloro Derivatives
[0217] Chloro derivatices of the present invention were prepared according to the following reaction scheme 11. The detailed procedure is described in J. Organic Chemistry, 9, 359-372.
##STR00103##
VI. Synthetic Procedure of GK3-015
[0218] GK3-015 was prepared according to the following reaction scheme 12.
##STR00104##
VII. Synthetic Procedures of GK2-197, GK2-229, GK2-303
[0219] GK2-197, GK2-229, GK2-303 were prepared according to the following reaction in scheme 13.
##STR00105##
VIII. Synthetic Procedure of the 7-aminoquinoline
[0220] 7-aminoquinoline was prepared according to the following reaction in scheme 14.
##STR00106##
IX. Synthetic Procedure of Halo-Serotonin Analogs
[0221] Halo-serotonin analogs were prepared according to the following reaction in scheme 15.
##STR00107## ##STR00108##
Methods
Ezrin Purification
[0222] Expression of untagged WT and mutant (T567D) of ezrin constructs in pQE16 expression vector were propagated in E.coli strain M15 pREP4(Qiagen, Valencia, Calif.). T567D ezrin cDNA was prepared from WT ezrin cDNA by site directed mutagenesis by using QuickChange II XL Site-Directed Mutagenesis Kit (Stratagene, Cedar Creek, Tex.). Both ezrin proteins were purified using hydroxyapatite (Bio-Rad, Hercules, Calif.) column on AKTA Explorer machine and dialysed into 20 mM MES, 150 mM NaCl, pH6.7 as described previously (Reczek, D., et al., J. Cell Biol. 139, 169-179 (1997)). Protein purity was estimated based on absence of nonspecific bands on cootnassie stained gels.
Immunoprecipitation
[0223] For analysis of actin binding to FL and mutant ezrin, K12 cell lysate was incubated with recombinant ezrin protein, then subjected to immunoprecipitation with ezrin antibody (Sigma, St. Louis, Mo.) and immunoblotted with actin antibody (Santa Cruz, Santa. Cruz, Calif.). For analysis of inhibition of small molecules on ezrin phosphorylation and actin binding, K7M2 cell lysates were treated with compounds at 10 M concentration for 6 hours, followed by immunoprecipitation with the ezrin antibody and immunoblotted with phospho-ezrin (Cell Signaling, Danvers, Mass.), actin and ezrin antibodies.
In Vitro Kinase Assays
[0224] 500 ng of recombinant ezrin protein in kinase assay mix (200 M ATP) was incubated with the compounds at 1-100 M concentrations for 15 minutes on ice, then 50 ng PKC,.Math. (Millipore, Billerica, Mass.) was added. Reaction was performed at 30 C. for 30 min and stopped by adding 2 sample buffer. NSC305787 and NSC668394 profiling on PKC, .Math., and were performed by utilizing the Kinase Inhibitor Compound Profiling Service at Kinexus Bioinformatics Corporation (Vancouver, Calif.).
Surface Plasmon Resonance (SPR)
[0225] Compounds for initial screening were acquired from 4 libraries (Challenge Set, Diversity Set, Mechanistic Set and Natural Product Set) of the Developmental Therapeutics Program, National Cancer Institute. Their direct ezrin binding potential was analyzed by using Biacore T100 v2.0.3 instrument (GE Healthcare, Piscataway N.J.). The technique requires immobilization of the ligand on sensorchip and the analyte is then injected over the chip surface through a fluidics system. Existing interactions are measured based on total mass change on the chip surface. Recombinant WT ezrin protein was used as the ligand and immobilized on to a Biacore CMS sensorchip and compounds were injected one at a time as the binding interactions were recorded. HBS-P, which contained 10 mM Hepes (pH 7.4), 150 mM NaCl and 0.05% surfactant P-20 was used as the standard running buffer. At initial screening, each molecule was injected for 1 min at 10 or 100 M concentrations. Any molecule giving more than 10 resonance units (RU) binding signal with an acceptable curve shape was selected as an initial hit. During detailed SPR analysis, NSC305787 was injected at 1 M, 2 M, 4 M, 8 M, 32 M and 64 M concentrations in duplicates. NSC668394 was injected at 1,5 M, 3 M, 6 M, 12.5 M, 25 .sub.M, 50 M and 100 M concentrations in triplicates. Results were analyzed by using Biacore T-100 v2.0.3 analysis software.
Chemotaxis, Cell Viability Assays
[0226] Chemotaxis experiments were performed in 96 well Boyden chamber as described previously (Chen. K., et al., Pediatr. Blood Cancer, 51, 349-355 (2008)). To measure effect of compounds on cellular toxicity, WST viability assay (Roche, Indianapolis, Ind.) was performed in parallel to chemotaxis experiments.
Invasion Assays
[0227] The anti-invasive potential of NSC305787 and NSC668394 were evaluated by using electric cell impedance sensing (ECIS) on a Roche xCELLigence system (Roche, Indianapolis, Ind.). Briefly, HUVEC cells (25,000/well) were seeded in a 96-well plate in EGM-2 media (Lonza, Basel, CH). Following formation of a confluent HUVEC monolayer (app 32 hrs), EGM-2 media was aspirated and a layer of OS cells (10,000 cells/well) was added in DMEM media containing the compounds. This time point was accepted as 0 hr of treatment and invasion was monitored during the following 6 hrs by measuring changes in resistance at the cell-electrode interphase.
Zebrafish Embryo Development Assay
[0228] Animals. Zebrafish (Danio rerio) were raised, maintained and crossed as described before (Westerfield, M. University of Oregon Press, Eugene. Oreg., 1993), Development of embryos was studied at 28 C. and staging was determined by morphological characteristics (Kimmel, C. B., et al., Dev. Dyn. 203, 253-310 (1995)).
Morpholino Oligonucleotide Injections.
[0229] A translation blocking anti-ezrin morpholine oligonucleotide (MO), described and validated by Link et al. (Link, V., et al., J. Cell Sci., 119, 2073-2083 (2006)), MO1, 5-CGCGAACATTTACTGGTTTAGG (SEQ ID NO:1), was synthesized by Gene-Tools, LCC (Philomath, Oreg.). MOs were microinjected into one to four cell stage embryos. Chemical screening.
[0230] Zebrafish embryos were arrayed, three per well, in 96-well plates. Compounds were added at 1-33 M concentrations. Embryos were observed, and photographed, at 70% epiboly, 24-28 hours post fertilization (hpf) and 48 hpf.
Pulmonary Metastasis Assay (PuMA)
[0231] The technique of isolated lung organ culture was performed as reported by Mendoza et al (Mendoza, A., et al., J. Clin. Invest., 120(8):2979-2988 (2010)).
In Vivo Experimental Metastasis Model
[0232] GFP expressing K7M2 or MNNG tumor cells (110.sup.6) were delivered by tail vein to nude mice. One day after injection, vehicle, NSC305787 (240 g/kg/inj) and NSC 608394 (226 g/kg/inj) were injected 5 days a week intraperitoneally.
Statistical Analysis
[0233] Statistical analyses were performed with Prism (GraphPad Software, LaJolla, Calif.).
Results
[0234] Initial Screening of Small Molecules for Direct Binding to ezrin
[0235] Small molecule libraries were screened to identify compounds that directly bind to ezrin protein. To achieve this goal, full-length recombinant ezrin protein was expressed in bacteria and the protein was purified by column chromatography as described earlier (Reczek, D., et al., J. Cell Biol., 139, 169-179 (1997)). Recombinant full length ezrin was prepared to a concentration of 100 g/ml with >90% purity (
[0236] The secondary functional assays used for lead compound selection included ezrin phosphorylation, actin binding, chemotaxis, zebrafish embryonic development and mouse lung organ culture. Furthermore, drugability based on their solubility, potential in vivo toxicity, chemical stability and potential for derivatization were also considered for elimination of some primary hits.
NSC305787 and NSC668394 Inhibit Endogenous Ezrin 1567 phosphorylation and Actin Binding.
[0237] Ezrin phosphorylation at T567 is critical for its activation, which then enables interaction of ezrin with other cellular proteins including actin (Matsui, T., et al., J. Cell Biol., 140, 647-657 (1998)). Both NSC305787 and NSC668394 inhibited T567 phosphorylation and actin binding of ezrin at 10 M concentration in K7M2 OS cells. Treatment with the compounds did not alter cellular ezrin protein levels (
Kinase Independent Inhibition of Ezrin T567 phosporylation by PKC, by Directly Targeting the Substrate.
[0238] Dynamic regulation of ezrin phosphorylation during metastatic progression is linked to protein kinase C (PKC) activation. Members of this family of serine/threonine kinases that phosphorylate ezrin at T567 in OS cells include PKC, alpha (), iota (.Math.) and gamma () (Ren, L., et al., Oncogene, 28, 792-802 (2009)). Phosphorylation of ezrin by PKC,.Math. was inhibited by NSC305787 with an IC.sub.50 of 5.5 M and by NSC668394 with an IC.sub.50 of 7.81 M (
[0239] Furthermore, direct interaction experiments with Biacore in SPR analysis revealed that NSC668394 bound to PKC,.Math. with a K.sub.D of 160.2 M and NSC305787 bound to PKC,.Math. with a K.sub.D of 172.4 M (data not shown). These results strongly suggest that NSC305787 and NSC668394 inhibit ezrin T567 phosphorylation primarily due to their binding to ezrin and not due to inhibition of PKC,.Math. kinase activity.
OS Cell's Invasive Phenotype is Inhibited by NSC305787 and NSC668394
[0240] Higher levels of ezrin protein in K7M2 cells compared to K12 cells leads to enhanced metastatic potential of K7M2 cells (
NSC305787 and NSC668394 Inhibit Cell Motility During Zebrafish Embryonic Development
[0241] Inhibition of ezrin protein expression by morpholine oligonucleotides (MO) results in a unique phenotype in zebrafish embryos (Link, V., et al., J. Cell Sci., 119, 2073-2083 (2006)). All 65 primary hit compounds were tested on early zebrafish embryo development. Small molecules that killed the embryos prior to 70% epiboly during gastrulation were eliminated based on toxicity. The ezrin MO phenotype, characterized by reduced epiboly movements resulting from defective germ layer morphogenesis, was confirmed by microinjection of MO1 as described by Link et al. (
Prevention of Metastastatic Growth in a Lung Organ Culture Assay
[0242] In OS, the predominant site of recurrence and main cause of death is pulmonary metastasis (Dunn, D. &. Dehner, L. P., Cancer, 40, 3054-3064 (1977)). An ex vivo mouse lung organ culture assay was performed to evaluate the inhibitory potential of the lead compounds. In this method, tumor cells reaching the lung following tail vein injection grew in the lung slices kept in organ culture, resembling in vivo lung metastasis (Ren, L., et al., Oncogene, 28, 792-802 (2009)). When green fluorescent protein (GFP) expressing metastatic K7M2 cells were injected through tail vein of mice, metastatic foci were followed up in the lung organ cultures, which was quantitated by GFP fluorescence. When mice were injected with less metastatic and low ezrin expressing K12 cells, no surviving tumor cells were observed in organ culture (data not shown). NSC305787 and NSC668394 treatment at 10 M concentration significantly inhibited the lung metastasis of K7M2 high ezrin expressing OS cells in this organ culture assay (
NSC305787 and NSC668394 Inhibit Ezrin Dependent in vivo OS Metastasis Growth in Mouse Lung.
[0243] After observing inhibition of lung metastatic growth in lung organ culture, the effects of NSC305787 and NSC668394 on in vivo lung metastasis model were tested. Following injection of GFP expressing K7M2 cells through tail vein, vehicle treated animals died due to progressive lung metastases in approximately 4 weeks (median survival 28.5 days). NSC305787 and NSC668394 treated animals survived up to 50 and 49 days, respectively (
[0244] MNNG is a human OS cell line and maintains its metastatic phenotype even after inhibition of ezrin expression by siRNA (data not shown). MNNG cells were used as a negative control for ezrin-dependent specificity. Animals injected with GFP expressing MNNG cells by tail vein and treated with NSC305787 and NSC668394 did not demonstrate any difference in survival between control and treatment groups. Median survival of vehicle, NSC305787 and NSC668394 treated MNNG cells were 50.5, 49, and 48.5 days, respectively (
[0245] The present invention is not to be limited in scope by the specific embodiments disclosed in the examples which are intended as illustrations of a few aspects of the invention and any embodiments which are functionally equivalent are within the scope of this invention. Indeed, various modifications of the invention in addition to those shown and described herein will become apparent to those skilled in the art and are intended to fall within the appended claims.
[0246] A number of references have been cited, the entire disclosures of which are incorporated herein by reference.