c-Kit inhibitor 3

c-Kit-IN-3 (Compound 18) is a potent and selective c-KIT kinase inhibitor with an IC50s of 4 nM, 8 nM for c-KIT wt and c-KIT T670I, respectively. c-Kit-IN-3 displays great potencies against most of the gain-offunction mutations in the juxtamembrane domain, drugresistant mutations in the ATP binding pocket, and activation loops[1].

Research Areas >> Cancer

Signaling Pathways >> Protein Tyrosine Kinase/RTK >> c-Kit

IC50: 4 nM (c-KIT kinase)[1]

c-Kit-IN-3 (Compound 18; 0.1-10 μM; 6 days; primary GIST patient cells) exhibits dose-dependent antiproliferative effects[1]. c-Kit-IN-3 (0.01-1 μM; 24 hours; GIST-T1, GIST-T1-T670I, and GIST-5R cells) treatment induces dose-dependent cell apoptotic death (by examining the cleaved PARP and cleaved caspase 3)[1]. c-Kit-IN-3 (0.01-1 μM; 24 hours; GIST-T1, GIST-T1-T670I, and GIST-5R cells) treatment arrests the cell cycle into the G0/G1 phase in all of these three cell lines[1]. c-Kit-IN-3 (0-1 μM; 24 hours) blocks the autophosphorylation of c-KIT pY703, pY719, and pY823 in GIST-T1, GIST-T1-T670I, and GIST-5R, respectively, cells at a concentration of 30 nM and inhibits the downstream signaling mediators pAKT (T308/S473), pS6 (S235/236), and pERK (T202/204)[1].  c-Kit-IN-3 potently inhibits the activity of CSF1R (IC50: 18 nM), PDGFRα (IC50: 25 nM), RET (IC50: 34 nM), and it relatively less potently inhibits DDR1 (IC50: 135 nM), FLT4 (IC50: 121 nM), and PDGFRβ (IC50: 97 nM)[1]. c-Kit-IN-3 (0.006 μM-1.37 μM) potently inhibits the growth of c-KIT-dependent GIST cancer cells, such as GIST-T1 (IC50: 0.006 μM); GIST-882 (IC50: 0.013 μM); GIST-T1-T670I (IC50: 0.011 μM); GIST-5R (IC50: 0.073 μM); GIST-48B (IC50: 1.37 μM), respectively[1]. Cell Proliferation Assay[1] Cell Line: Primary GIST patient cells Concentration: 0.1 μM, 0.3 μM, 1 μM, 3 μM, 10 μM Incubation Time: 6 days Result: Inhibition of the proliferation of primary GIST patient cells. Cell Cycle Analysis[1] Cell Line: GIST-T1, GIST-T1-T670I, and GIST-5R cells Concentration: 0.01 μM, 0.03 μM, 0.1 μM, 0.3 μM, 1 μM Incubation Time: 24 hours Result: Arrested the cell cycle into the G0/G1 phase in all of these three cell lines. Apoptosis Analysis[1] Cell Line: GIST-T1, GIST-T1-T670I, and GIST-5R cells Concentration: 0.01 μM, 0.03 μM, 0.1 μM, 0.3 μM, 1 μM Incubation Time: 24 hours Result: Induced dose-dependent cells apoptotic death. Western Blot Analysis[1] Cell Line: GIST-T1, GIST-T1-T670I, and GIST-5R cells Concentration: 0.01 μM, 0.03 μM, 0.1 μM, 0.3 μM, 1 μM Incubation Time: 24 hours Result: Decreased the autophosphorylation of c-KIT pY703, pY719, and pY823 in GIST-T1, GIST-T1-T670I, and GIST-5R cells, respectively.

c-Kit-IN-3 (Compound 18; 40-100 mg/kg; oral gavage; daily; for 11 days; for 4 weeks; female BALB/C-nu mice) treatment dose dependently inhibits the BaF3-tel-c-KIT-T670I tumor progression and exhibited almost 100% TGI (tumor growth inhibition) at a dosage of 100 mg/kg/day. And do not affect the animal weights[1]. Animal Model: Female BALB/C-nu mice bearing established BaF3-tel-c-KIT-T670I tumor xenografts[1] Dosage: 40 mg/kg, 100 mg/kg Administration: Oral gavage; daily; for 11 days Result: Dose dependently inhibited the BaF3-tel-c-KIT-T670I tumor progression and exhibited almost 100% TGI (tumor growth inhibition) at a dosage of 100 mg/kg/day.

[1]. Wu Y, et al. Discovery of 2-(4-Chloro-3-(trifluoromethyl)phenyl)-N-(4-((6,7-dimethoxyquinolin-4-yl)oxy)phenyl)acetamide (CHMFL-KIT-64) as a Novel Orally Available Potent Inhibitor against Broad-Spectrum Mutants of c-KIT Kinase for Gastrointestinal Stromal Tumors. J Med Chem. 2019 Jul 11;62(13):6083-6101.