| In Vitro | In vitro activity: MK-2461 also potently inhibits FGFR1, FGFR2, FGFR3, KDR, TrkA, TrkB, and Flt4 with IC50 of 65 nM, 39 nM, 50 nM, 44 nM, 46 nM, 61 nM, and 78 nM, respectively. Compared with wild-type c-Met, MK-2461 more potently inhibits the activity of oncogenic c-Met kinase mutants such as N1100Y, Y1230C, Y1230H, Y1235D, and M1250T with IC50 of 1.5 nM, 1.5 nM, 1.0 nM, 0.5 nM, and 0.4 nM, respectively. MK-2461 binds more strongly to phosphorylated c-Met than to unphosphorylated c-Met. MK-2461 potently inhibits ATP-induced autophosphorylation of the COOH-terminal docking domain of c-Met, but not the activation loop. In contrast, MK-2461 inhibits phosphorylation of the activation loop of FGFR2 (Y653/Y654) in Kato III cells and PDGFRα (Y849) in H1703 cells with IC50 of<0.3 μM. MK-2461 inhibits HGF-induced mitogenesis of 4MBr-5 cells with IC50 of 204 nM, and HGF-induced migration of HPAF II cells with IC50 of 404 nM, as well as HGF-induced branching tubulogenesis of MDCK cells. In addition, MK-2461 potently inhibits IL-3-independent proliferation of 32D cells transformed with Tpr-Met or Tpr-Met (Y362C) mutant with IC50 of ~100 nM. MK-2461 significantly inhibits the proliferation of a large panel of tumor cell lines, especially potent against tumor cells harbored genomic amplification of MET or FGFR2.
Kinase Assay: The c-Met–catalyzed phosphorylation of N-biotinylated peptide (EQEDEPEGDYFEWLE-CONH2) is measured using a time-resolved fluorescence resonance energy transfer assay. The MK-2461 IC50 for Ron, Mer, Flt1, Flt3, Flt4, KDR, PDGFRβ, FGFR1, FGFR2, FGFR3, TrkA, and TrkB are determined using time-resolved fluorescence resonance energy transfer assays similar to the c-Met kinase assay.
Cell Assay: Cells (SW480, HT29, SW620, Colo 205, HCT116, HCT15, Colo 201, SCC-9, H1993, H1048, GTL-16, SNU15, et al.) are exposed to various concentrations of MK-2461 for 72 hours. The viability of tumor cells is measured using the ViaLight PLUS kit. |
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