Increased HGF Expression Induces Resistance to c-MET Tyrosine Kinase Inhibitors in Gastric Cancer.

Increased expression of hepatocyte growth factor (HGF) and MET proto-oncogene (c-MET) is associated with poor prognosis in various cancer types. Recently, it was reported that the expression of HGF induces resistance to tyrosine kinase inhibitors (TKIs) targeting epidermal growth factor receptor, human epidermal receptor receptor 2, and b-raf proto-oncogene. Here, we investigated the effects of HGF overexpression in gastric cancer cells in the absence or presence of c-MET TKIs. The effects of c-MET TKIs in gastric cancer cells with and without c-MET overexpression were determined in gastric cancer cell lines with various cell biology methods. Compared to the control, cells with induced expression of HGF showed increase in anchorage-independent colony formation (p<0.001). The c-MET TKIs inhibited HGF/c-MET downstream signaling, cell proliferation, migration and invasion, and triggered cell-cycle arrest in Hs746T cells. However, HGF-transfected cells were less affected. c-MET TKIs had inhibitory effects only on cells overexpressing c-MET. Furthermore, overexpression of HGF resulted in resistance to c-MET TKIs through an autocrine manner in gastric cancer cells.

Ahn SY ，Kim J ，Kim MA ，Choi J ，Kim WH ... -  《-》

Co-expression of hepatocyte growth factor and c-Met predicts peritoneal dissemination established by autocrine hepatocyte growth factor/c-Met signaling in gastric cancer.

Epithelial-mesenchymal transition (EMT) promotes and facilitates migration and invasion of epithelial tumor cells. EMT is induced by factors such as hepatocyte growth factor (HGF). This study aimed to establish whether the HGF/c-Met pathway is associated with gastric cancer metastasis; especially peritoneal dissemination. HGF and c-Met expression and EMT-related molecules were evaluated using real-time PCR and immunohistochemistry. The role of the HGF/c-Met pathway in EMT and anoikis was determined, and kinase inhibitor SU11274 was tested for its ability to block HGF-induced biological effects. In HGF(-) /c-Met(+) gastric cancer cells, recombinant HGF promoted an EMT phenotype that was characterized by morphology, impaired E-cadherin and induction of vimentin. HGF promoted cell growth, invasiveness and migration and inhibition of anoikis. SU11274 blocked HGF-induced EMT and biological effects in vitro. In HGF(+) /c-Met(+) gastric cancer cells, HGF did not affect the biological outcome of EMT and anoikis, but SU11274 exerted the same inhibitory effects as in HGF(-) /c-Met(+) cells. In vivo, HGF(+) /c-Met(+) gastric cancer cells only established peritoneal dissemination and SU11274 inhibited tumor growth. Clinically, HGF expression was significantly correlated with c-Met expression in gastric cancer. Increased HGF and c-Met had a significant association with poor prognosis and predicted peritoneal dissemination. We demonstrated that the HGF/c-Met pathway induces EMT and inhibition of anoikis in gastric cancer cells. Co-expression of HGF and c-Met has the potential to promote peritoneal dissemination in gastric cancer. Blockade of the autocrine HGF/c-Met pathway could be clinically useful for the treatment of peritoneal dissemination in gastric cancer.

Toiyama Y ，Yasuda H ，Saigusa S ，Matushita K ，Fujikawa H ，Tanaka K ，Mohri Y ，Inoue Y ，Goel A ，Kusunoki M ... -  《-》

Norcantharidin combined with EGFR-TKIs overcomes HGF-induced resistance to EGFR-TKIs in EGFR mutant lung cancer cells via inhibition of Met/PI3k/Akt pathway.

Wu H ，Fan F ，Liu Z ，Shen C ，Wang A ，Lu Y ... -  《-》

Fibroblast-secreted hepatocyte growth factor mediates epidermal growth factor receptor tyrosine kinase inhibitor resistance in triple-negative breast cancers through paracrine activation of Met.

Mueller KL ，Madden JM ，Zoratti GL ，Kuperwasser C ，List K ，Boerner JL ... -  《-》

Dual inhibition of Met kinase and angiogenesis to overcome HGF-induced EGFR-TKI resistance in EGFR mutant lung cancer.

Acquired resistance to epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) is a serious problem in the management of EGFR mutant lung cancer. We recently reported that hepatocyte growth factor (HGF) induces resistance to EGFR-TKIs by activating the Met/PI3K pathway. HGF is also known to induce angiogenesis in cooperation with vascular endothelial growth factor (VEGF), which is an important therapeutic target in lung cancer. Therefore, we hypothesized that dual inhibition of HGF and VEGF may be therapeutically useful for controlling HGF-induced EGFR-TKI-resistant lung cancer. We found that a dual Met/VEGF receptor 2 kinase inhibitor, E7050, circumvented HGF-induced EGFR-TKI resistance in EGFR mutant lung cancer cell lines by inhibiting the Met/Gab1/PI3K/Akt pathway in vitro. HGF stimulated VEGF production by activation of the Met/Gab1 signaling pathway in EGFR mutant lung cancer cell lines, and E7050 showed an inhibitory effect. In a xenograft model, tumors produced by HGF-transfected Ma-1 (Ma-1/HGF) cells were more angiogenic than vector control tumors and showed resistance to gefitinib. E7050 alone inhibited angiogenesis and retarded growth of Ma-1/HGF tumors. E7050 combined with gefitinib induced marked regression of tumor growth. Moreover, dual inhibition of HGF and VEGF by neutralizing antibodies combined with gefitinib also markedly regressed tumor growth. These results indicate the therapeutic rationale of dual targeting of HGF-Met and VEGF-VEGF receptor 2 for overcoming HGF-induced EGFR-TKI resistance in EGFR mutant lung cancer.

Takeuchi S ，Wang W ，Li Q ，Yamada T ，Kita K ，Donev IS ，Nakamura T ，Matsumoto K ，Shimizu E ，Nishioka Y ，Sone S ，Nakagawa T ，Uenaka T ，Yano S ... -  《-》