Low dosage of arsenic trioxide (As2O3) inhibits angiogenesis in epithelial ovarian cancer without cell apoptosis.

Arsenic trioxide (As2O3) induces cell apoptosis and reduces the invasive and metastatic activities in various cancer types. However, the role of As2O3 in ovarian cancer angiogenesis remains unclear. In this study, we investigated the role of As2O3 in ovarian cancer angiogenesis and found that a low concentration of As2O3 causes no effects on epithelial ovarian cancer cell viability or apoptosis. Moreover, we found that As2O3-treated epithelial ovarian cancer cells demonstrate a reduced tube formation of endothelial cells in Matrigel. In addition, As2O3-treated epithelial ovarian cancer cells show a decreased VEGFA, VEGFR2 and CD31 mRNA expression. As per the underlying mechanisms involved in As2O3 treatment, we found that As2O3 inhibits VEGFA and VEGFR2 expression that thereby inhibits the VEGFA-VEGFR2-PI3K/ERK signaling pathway. This leads to a suppression in both VEGFA synthesis and angiogenesis-related gene expression. A decreased VEGFA synthesis and secretion also inhibits the VEGFA-VEGFR2-PI3K/ERK signaling pathway in human umbilical vein endothelial cells (HUVECs). In summary, our results may provide strategies for the use of As2O3 in the prevention of tumor angiogenesis.