Blockade of ONECUT2 expression in ovarian cancer inhibited tumor cell proliferation, migration, invasion and angiogenesis.

One cut homeobox 2 (ONECUT2 or OC-2) is a newly discovered transcription factor. Aberrant expression of OC-2 is closely related to cell proliferation, migration, invasion, and angiogenesis. In this study, we found that OC-2 expression was upregulated in ovarian adenocarcinoma cells, by Western blot analysis. The results of immunohistochemistry showed that the expression of OC-2 was also increased in malignant ovarian cancer tissue. In order to explore the role of OC-2 in the development of ovarian cancer, siRNAs that specifically targets OC-2 were designed. The siRNA targeting OC-2 could effectively inhibit the vascular endothelial growth factor A (VEGFA) expression, but silence and overexpression of VEGFA did not affect OC-2 expression. In addition, OC2-siRNA could block the proliferation, migration, and invasion, and inhibit epithelial-mesenchymal transition and the AKT/ERK signaling pathway, of human ovarian cancer cells in vitro. In a mouse model of ovarian cancer xenograft tumors, OC2-siRNA could significantly inhibit tumor cell growth and the tumor inhibition rate reached approximately 73%. The results of immunohistochemistry showed that the densities of microvessels stained with CD31, the expression of OC-2 and VEGFA were significantly decreased in tumors. These data indicated that OC-2 was an upstream regulator of VEGFA and silencing OC-2 could inhibit ovarian cancer angiogenesis and tumor growth.