[Effect of c-Met inhibitor AMG-102 on radiosensitivity in laryngeal squamous carcinoma cells].

Objective: To investigate the effect of c-Met inhibitor AMG-102 on proliferation and radiosensitivity in laryngeal squamous carcinoma cells. Methods: The effects of AMG-102 on proliferation and radiosensitivity of laryngeal squamous carcinoma cell lines Hep-2 and KBV200 were detected by 3-(4, 5-dimethy-2-thiazolyl)-2, 5-diphenyl-2H tetrazolium bromide (MTT) assay and colony formation assay, respectively. The apoptosis of Hep-2 and KBV200 cells was detected by flow cytometry. The expression levels of c-Met, phospho-Met (p-Met), cleaved caspase-3 and Akt/p-Akt, Erk/p-Erk were detected by Western blot. Specific small interfering RNA targeting c-Met or plasmid of c-Met were transfected into Hep-2 and KBV200 cells to investigate the cell sensitivity to AMG-102. Results: Compared with KBV200 cells, Hep-2 cells were more sensitive to AMG-102 with IC(50) of 14 and 9 mumol/L, respectively. The relative expression levels of c-Met and p-Met proteins in Hep-2 cells were 194.48+/-0.57 and 177.76+/-1.53, respectively, which were significantly higher than those in KBV200 cells (171.24+/-1.00 and 115.37+/-0.56, respectively, P 0.05). The sensitivity of Hep-2 cells to AMG-102 was decreased after silencing of c-Met, while the sensitivity of KBV200 cells to AMG-102 was not significantly changed (P>0.05). Moreover, the radiosensitivity of Hep-2 cells in c-Met knockdown group had a slightly increasing trend (SER=1.07, P=0.068). After the treatment with 10 mumol/L of AMG-102, the proliferation rate of c-Met ectopically expressed KBV200 cells was 60.05%+/-3.23%, It was significantly lower than that of the blank control 90.08%+/-1.04% and siRNA negative control (90.12%+/-1.01%, P<0.001). The results suggested that the overexpression of c-Met in KBV200 cells increased the radiosensitivity to AMG-102, whereas depletion of c-Met resulted in resistance to AMG-102 in Hep-2 cells. Furthermore, the radiosensitivity of KBV200 cells that overexpressed c-Met showed a decreased trend (SER=0.7, P=0.005). Conclusions: c-Met inhibitor AMG-102 has a significant inhibitory effect on the proliferation of c-Met overexpressing laryngeal squamous carcinoma cells, leading to increased radiosensitivity. It suggests that molecular targeted therapy against c-Met receptor is more effective in c-Met overexpressed subtype of laryngeal squamous cell carcinoma.