Fascin Regulates the Hippo Pathway and Is Important for Melanoma Development.

ABSTRACT

BACKGROUND/AIM: Fascin, an actin-bundling protein, plays an essential role in cancer metastasis. The Hippo pathway is critical for carcinogenesis and cancer stem cell self-renewal. Mammalian STE20-like kinase (MST) is a core component of the Hippo pathway. However, whether fascin and MST2 affect melanoma remain largely unknown. This study aimed to investigate the role of fascin and MST2 in melanoma development. MATERIALS AND METHODS: Surgically excised skin melanomas and the adjacent non-tumorous skin tissue from 30 cases were analyzed using immunohistochemistry for fascin and MST2. The melanoma cell line WM793 was employed for fascin and MST2 knock-down followed by western blotting, and melanoma xenografting in BALB/c mice. RESULTS: Immunohistochemistry revealed increased expression of fascin and decreased expression of MST2 in melanoma. The reverse correlation of fascin and MST2 was statistically significant. Fascin siRNA upregulated MST2 expression; however, MST2 siRNA did not significantly affect fascin expression in the WM793. WM793 xenografting followed by fascin knock-down inhibited tumor growth significantly in the animal study. CONCLUSION: Fascin is a regulator of the Hippo pathway and plays an important role in melanoma development. Therefore, fascin could be a potential therapeutic target for melanoma.