Metformin inhibits the development and metastasis of ovarian cancer.

The aim of this study was to investigate the role of metformin in the regulation of development and metastasis of ovarian carcinoma cell lines in vitro and ovarian cancer in a nude mouse model in vivo. The effects of metformin on the ability of two high-metastatic potential human ovarian cancer cell lines (SKOV3 and HO8910-PM) to adhere, invade and migrate in vitro were observed by means of a cell adhesion test, cell invasion test and cell migration test. The size and number of the inoculated and metastatic tumours in vivo in a nude mouse were determined following intraperitoneal injection of metformin. Furthermore, the extent of angiogenesis (vWF) and macrophage infiltration in the tumour were determined. Proliferation, migration, invasion and adhesion of ovarian cancer cells were significantly inhibited (P<0.05) in a dose-dependent manner in vitro. In addition, metformin inhibited hepatic, intestinal and lung metastasis (P<0.05), with no weight loss in vivo, consistent with decreased expression of vWF and macrophage infiltration. Our data suggest that metformin inhibits the development and metastasis of ovarian cancer by reducing cellular-ECM interactions, neovascularisation and macrophage infiltration.