In vitro activity: PF-2341066 displays similar potency against c-Met phosphorylation in mIMCD3 mouse or MDCK canine epithelial cells with IC50 of 5 nM and 20 nM, respectivly. PF-2341066 shows improved or similar activity against NIH3T3 cells engineered to express c-Met ATP-binding site mutants V1092I or H1094R or the P-loop mutant M1250T with IC50 of 19 nM, 2 nM and 15 nM, respectively, compared with NIH3T3 cells expressing wild-type receptor with IC50 of 13 nM. In contrast, a marked shift in potency of PF-2341066 is observed against cells engineered to express c-Met activation loop mutants Y1230C and Y1235D with IC50 of 127 nM and 92 nM, respectively, compared with wild-type receptor. PF-2341066 also potently prevents the phosphorylation of c-Met in NCI-H69 and HOP92 cells, with IC50 of 13 nM and 16 nM, respectively, which express the endogenous c-Met variants R988C and T1010I, respectively. PF-2341066 is>1,000-fold selective for the VEGFR2 and PDGFRβ RTKs,>250-fold selective for IRK and Lck, and ~40- to 60-fold selective for Tie2, TrkA, and TrkB, all compared with c-Met. PF-2341066 is 20- to 30-fold selective for RON and Axl RTKs. In contrast, PF-2341066 shows a near-equivalent IC50 of 24 nM against the nucleophosmin (NPM)-anaplastic lymphoma kinase (ALK) oncogenic fusion variant of the ALK RTK expressed by the KARPAS299 human anaplastic large cell lymphoma (ALCL) cell line. PF-2341066 inhibits c-Met–dependent neoplastic phenotypes of cancer cells and angiogenic phenotypes of endothelial cells. PF-2341066 suppresses human GTL-16 gastric carcinoma cell growth with IC50 of 9.7 nM. PF-2341066 induces apoptosis in GTL-16 cells with IC50 of 8.4 nM. PF-2341066 inhibits HGF-stimulated human NCI-H441 lung carcinoma cell migration and invasion with IC50 of 11 nM and 6.1 nM, respectively. PF-2341066 inhibits MDCK cell scattering with IC50 of 16 nM. PF-2341066 prevents HGF-stimulated c-Met phosphorylation, cell survival, and Matrigel invasion with IC50 of 11 nM, 14 nM and 35 nM, respectively. In addition, PF-2341066 prevents serum-stimulated HMVEC branching tubulogenesis (formation of vascular tubes) in fibrin gels. PF-2341066 also potently inhibits NPM-ALK phosphorylation in Karpas299 or SU-DHL-1 ALCL cells with an IC50 of 24 nM. PF-2341066 potently prevents cell proliferation, which is associated with G(1)-S-phase cell cycle arrest and induction of apoptosis in ALK-positive ALCL cells with IC50 of 30 nM, but not ALK-negative lymphoma cells. Besides, PF-2341066 prevents osteosarcoma behavior associated with primary tumor growth (i.e., proliferation and survival) as well as metastasis (eg, invasion and clonogenicity).

Kinase Assay: Cells are seeded in 96-well plates in media supplemented with 10% fetal bovine serum (FBS) and transferred to serum-free media [with 0.04% bovine serum albumin (BSA)] after 24 h. In experiments investigating ligand-dependent RTK phosphorylation, corresponding growth factors are added for up to 20 min. After incubation of cells with PF-2341066 for 1 h and/or appropriate ligands for the designated times, cells are washed once with HBSS supplemented with 1 mM Na3VO4, and protein lysates are generated from cells. Subsequently, phosphorylation of selected protein kinases is assessed by a sandwich ELISA method using specific capture antibodies used to coat 96-well plates and a detection antibody specific for phosphorylated tyrosine residues. Antibody-coated plates are (a) incubated in the presence of protein lysates at 4°C overnight; (b) washed seven times in 1% Tween 20 in PBS; (c) incubated in a horseradish peroxidase–conjugated anti–total-phosphotyrosine (PY-20) antibody (1:500) for 30 min; (d) washed seven times again; (e) incubated in 3,3′,5,5′-tetramethyl benzidine peroxidase substrate to initiate a colorimetric reaction that is stopped by adding 0.09 N H2SO4; and (f) measured for absorbance in 450 nm using a spectrophotometer.

Cell Assay: Cells (GTL-16 gastric carcinoma cells and T47D breast carcinoma cells) including GTL-16 gastric carcinoma cells and T47D breast carcinoma cells are seeded in 96-well plates in media supplemented with 10% fetal bovine serum (FBS) and transferred to serum-free media [with 0.04% bovine serum albumin (BSA)] after 24 hours. In experiments investigating ligand-dependent RTK phosphorylation, corresponding growth factors are added for up to 20 minutes. After incubation of cells with PF-2341066 for 1 hour and/or appropriate ligands for the designated times, cells are washed once with HBSS supplemented with 1 mM Na3VO4, and protein lysates are generated from cells. Subsequently, phosphorylation of selected protein kinases is assessed by a sandwich ELISA method using specific capture antibodies used to coat 96-well plates and a detection antibody specific for phosphorylated tyrosine residues. Antibody-coated plates are (a) incubated in the presence of protein lysates at 4 °C overnight; (b) washed seven times in 1% Tween 20 in PBS; (c) incubated in a horseradish peroxidase–conjugated anti–total-phosphotyrosine (PY-20) antibody (1:500) for 30 min; (d) washed seven times again; (e) incubated in 3,3′,5,5′-tetramethyl benzidine peroxidase substrate to initiate a colorimetric reaction that is stopped by adding 0.09 N H2SO4; and (f) measured for absorbance in 450 nm using a spectrophotometer.

Cancer Res. 2007 May 1;67(9):4408-17; Mol Cancer Ther. 2007 Dec;6(12 Pt 1):3314-22; J Nucl Med. 2011 Aug;52(8):1261-7.