Inhibition of angiogenesis and tumor progression of MK-0429, an integrin alphavbeta(3) antagonist, on oral squamous cell carcinoma.

PURPOSE: Integrin alphavbeta(3) is an essential molecule for tumor angiogenesis. This study aimed to investigate the anti-tumor effect of MK-0429, an integrin alphavbeta(3) antagonist, on oral squamous cell carcinoma (OSCC) through its inhibitory effect on angiogenesis. METHODS: In this study, we investigated the effect of MK-0429 on cellular function and angiogenesis in vitro with the use of an immortalized human umbilical vein endothelial cell, HUEhT-1, which is immortalized by the electroporatic transfection of hTERT. The effect of MK-0429 on the integrin alphavbeta(3) signaling pathway was examined by FAK, MEK1/2 and ERK 1/2 phosphorylation. The anti-angiogenic effect of MK-0429 was evaluated by in vitro tube formation assay. The anti-tumor effect on OSCC was assessed by administrating MK-0429 to mouse oral cancer xenografts. RESULTS: MK-0429 inhibited cell proliferation, migration, and adhesion of HUEhT-1 in a dose-dependent manner. FAK, MEK and ERK phosphorylation were significantly blocked by MK-0429 treatment. Tube formation was suppressed by MK-0429 in dose-dependent manner. Tumor progression was significantly suppressed by MK-0429 administration in mouse oral cancer xenografts. Histological study revealed that MK-0429 decreased tumor vascularization. CONCLUSION: These results indicated integrin alphavbeta(3) as a therapeutic target for OSCC and suggested that MK-0429 might be clinically applicable as an anti-tumor agent with potent anti-angiogenic activity.