PHA-665752

MET

641, 61

Female athymic mice (nu/nu) bearing S114 or GTL-16 tumor xenografts

Dissolved in DMSO, final concentrations ca.10 uM

Formulated in vehicle (L-lactate (pH 4.8) and 10% polyethylene glycol)

PHA-665752 significantly inhibits c-Met kinase activity with Ki of 4 nM, and exhibits >50-fold selectivity for c-Met compared with various tyrosine and serine-threonine kinases. PHA-665752 potently inhibits the HGF-stimulated c-Met autophosphorylation with IC50 of 25-50 nM. PHA-665752 also significantly blocks HGF- and c-Met-dependent functions such as cell motility and cell proliferation with IC50 of 40-50 nM and 18-42 nM, respectively. In addition, PHA-665752 potently inhibits HGF-stimulated or constitutive phosphorylation of mediators of downstream of c-Met such as Gab-1, ERK, Akt, STAT3, PLC-gamma, and FAK in multiple tumor cell lines. [1] PHA-665752 inhibits cell growth in TPR-MET-transformed BaF3 cells with IC50 of <60 nM, and inhibits constitutive cell motility and migration by 92.5% at 0.2 uM. Inhibition of c-Met by PHA665752 (0.2 uM) also induces cell apoptosis of 33.1% and G1 cell cycle arrest with cells in G1 phase increasing from 42.4% to 77.0%. PHA665752 can cooperate with rapamycin to inhibit cell growth of TPR-MET-transformed BaF3 cells and non-small cell lung cancer H441 cells. [2]

18, or 72 hours

For proliferation assays, cells are grown in medium with 0.1% FBS for 48 hours after which they are treated with various concentrations of PHA-665752 in HGF (50 ng/mL) in a medium containing 2% FBS. After 18 hours, cells are incubated with BrdUrd for 1 hour, fixed, and stained with anti-BrdUrd peroxidase-conjugated antibody, and plates are read at 630 nm. For apoptosis assays, cells are grown in medium with 2% FBS in presence and absence of HGF (50 ng/mL) and various concentrations of PHA-665752 for 72 hours. After 72 hours, a mixture containing ethidium bromide and acridine orange is added, and apoptotic cells (bright orange cells or cell fragments) are counted by fluorescence microscopy.

PHA-665752 is a potent, selective and ATP-competitive c-Met inhibitor with IC50 of 9 nM in cell-free assays, >50-fold selectivity for c-Met than RTKs or STKs.