[CAS NO. 878739-06-1]  AZ 628

AZ628 prevents activation of number of tyrosine protein kinases including VEGFR2, DDR2, Lyn, Flt1, FMS and others. AZ628 suppresses anchorage-dependent and -independent growth, gives rise to cell cycle arrest, and induces apoptosis in colon and melanoma cell lines harboring B-RafV600E mutation. The profile of AZ628 cross-reactivity suggests that similar to sorafenib, AZ628 may be antiangiogenic based on prevention of VEGFR2. AZ628-resistant clones are approximately 100-fold more resistant to AZ628 than the parental cell line, exhibiting IC50 of approximately 10 μM, compared with 0.1 μM for the parental cell line. Effective suppression of p-ERK1/2 levels is observed in the M14 parental cell line following treatment with increasing concentrations of AZ628. AZ628-resistant clones express elevated CRAF. Elevated CRAF expression is a potential mechanism of acquired resistance to continuous AZ628 exposure, resulting in sustained activation of ERK1/2. p-ERK1/2 activity is not significantly inhibited by exposure to AZ628 in one of these three AZ628-insensitive cell lines (Wm1552C). Unlike in the AZ628-resistant M14 cells in which AZ628 fails to suppress the activation of ERK, AZ628 treatment efficiently attenuates ERK activation in the NRAS mutant melanoma cells.