Elevated Cathepsin K potentiates metastasis of epithelial ovarian cancer.

Cathepsin K, or CTSK, has been found to be involved in the peritoneal metastasis of ovarian carcinoma. However, the expression and clinicopathological significance of CTSK remains unknown in epithelial ovarian cancer (EOC). The aim of the present study was to investigate the expression of CTSK and its clinicopathological significance in EOC. CTSK expression was evaluated using immunohistochemistry in EOC tissue microarray. The expression of CTSK in EOC was displayed to be markedly higher than that of adjacent normal control. In addition, CSTK expression was shown to be remarkably associated with metastases and inferior overall prognosis of EOC. In vitro, Knock-down of CTSD was exhibited to be able to suppress migration and invasion in EOC cell lines OV-2008 but not proliferation in OV-2008. Together, our data showed that elevated CTSD in EOC can potentiate the metastasis of EOC cells, suggesting that targeting CTSD might be used as a novel therapeutic target for EOC.