title: Foretinib (GSK1363089), a multi-kinase inhibitor of MET and VEGFRs, inhibits growth of gastric cancer cell lines by blocking inter-receptor tyrosine kinase networks.
abstract: To explore the mechanism of action of foretinib (GSK1363089), an oral multi-kinase inhibitor known to target MET, RON, AXL, and vascular endothelial growth factor receptors (VEGFRs), in gastric cancer, we evaluated the effects of the agent on cell growth and cell signaling in the following panel of gastric cancer cell lines: KATO-III, MKN-1, MKN-7, MKN-45, and MKN-74. Of these, only MKN-45 and KATO-III, which harbor MET and fibroblast growth factor receptor 2 (FGFR2) amplification, respectively, were highly sensitive to foretinib. In MKN-45, 1 μM of foretinib or PHA665752, another MET kinase inhibitor, inhibited phosphorylation of MET and downstream signaling molecules as expected. In KATO-III, however, PHA665752 inhibited phosphorylation of MET independently of downstream molecules. Further, 1 μM of foretinib or PD173074, a selective FGFR kinase inhibitor, inhibited phosphorylation of FGFR2 and downstream molecules, suggesting that foretinib targets FGFR2 in KATO-III. We confirmed this novel activity of foretinib against FGFR2 in OCUM-2M, another FGFR2-amplified gastric cancer cell line. Using a phospho-receptor tyrosine kinase array, we found that foretinib inhibits phosphorylation of epidermal growth factor receptor (EGFR), HER3 and FGFR3 via MET inhibition in MKN-45, and EGFR, HER3 and MET via FGFR2 inhibition in KATO-III. Knockdown of HER3 and FGFR3 in MKN-45 with siRNA resulted in the partial inhibition of cell signaling and cell growth. In conclusion, foretinib appears effective against gastric cancer cells harboring not only MET but also FGFR2 amplification, and exerts its inhibitory effects by blocking inter-RTK signaling networks with MET or FGFR2 at their core.
authors.affiliation: Department of Hospital Pharmacy, Kobe University Hospital, 7-5-2, Kusunoki-cho, Chuo-ku, Kobe, Japan.
authors.forename: Yu
authors.initials: Y
authors.lastname: Kataoka
authors.forename: Toru
authors.initials: T
authors.lastname: Mukohara
authors.forename: Hideo
authors.initials: H
authors.lastname: Tomioka
authors.forename: Yohei
authors.initials: Y
authors.lastname: Funakoshi
authors.forename: Naomi
authors.initials: N
authors.lastname: Kiyota
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Fujiwara
authors.forename: Masakazu
authors.initials: M
authors.lastname: Yashiro
authors.forename: Kosei
authors.initials: K
authors.lastname: Hirakawa
authors.forename: Midori
authors.initials: M
authors.lastname: Hirai
authors.forename: Hironobu
authors.initials: H
authors.lastname: Minami
mesh_terms: D000813:Anilides / Q000494:pharmacology*; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D019008:Drug Resistance, Neoplasm / Q000187:drug effects; D004354:Drug Screening Assays, Antitumor; D066246:ErbB Receptors / Q000037:antagonists & inhibitors / Q000378:metabolism; D055785:Gene Knockdown Techniques; D006801:Humans; D008954:Models, Biological; D009363:Neoplasm Proteins / Q000378:metabolism; D010766:Phosphorylation / Q000187:drug effects; D047428:Protein Kinase Inhibitors / Q000494:pharmacology*; D019859:Proto-Oncogene Proteins c-met / Q000037:antagonists & inhibitors* / Q000378:metabolism; D011804:Quinolines / Q000494:pharmacology*; D051497:Receptor, Fibroblast Growth Factor, Type 2 / Q000037:antagonists & inhibitors / Q000378:metabolism; D040262:Receptors, Vascular Endothelial Growth Factor / Q000037:antagonists & inhibitors* / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects*; D013274:Stomach Neoplasms / Q000201:enzymology* / Q000473:pathology*
chemical_list: D000813:Anilides; C544831:GSK 1363089; D009363:Neoplasm Proteins; D047428:Protein Kinase Inhibitors; D011804:Quinolines; D066246:ErbB Receptors; D019859:Proto-Oncogene Proteins c-met; D051497:Receptor, Fibroblast Growth Factor, Type 2; D040262:Receptors, Vascular Endothelial Growth Factor