Antitumor effects of Nafamostat mesilate on head and neck squamous cell carcinoma.

Nafamostat mesilate (FUT-175), a synthetic serine protease inhibitor, has antitumor activities toward adenocarcinoma, e.g., colon cancer. However, its antitumor effects on other types of cancer have been less extensively studied. We investigated the biological activities of Nafamostat mesilate on cell proliferation, cell-invasive potential and growth factor production in head and neck squamous cell carcinoma (HNSCC).Two human HNSCC cell lines established in our department, YCU-L891 and -H891, and a human vulvar squamous cell carcinoma cell line, A431, were examined for the effect of Nafamostat mesilate. The effects on cell growth were evaluated using the MTT assay. The effects on the relative expression levels of mRNA were measured by quantitative RT-PCR. Cytokine secretion was analyzed by enzyme-linked immunosorbent assay.Nafamostat mesilate inhibited the proliferation of two HNSCC cell lines, YCU-L891 and YCU-H891, and A431. In these cell lines, Nafamostat mesilate down-regulated both matrix metalloproteinase (MMP)-2 and -9. In addition, it reduced the productions of vascular endothelial growth factor (VEGF) and transforming growth factor beta1 (TGF-beta1) by the tumor cells.Our results suggest that Nafamostat mesilate has potential for use as a treatment against local growth, invasion and metastasis of squamous cell carcinoma.