Adiponectin exhibits proliferative and anti-apoptotic effects on ovarian cancer cells via PI3K/Akt and Raf/MEK/ERK pathways

Purpose: To elucidate the effects and the underlying mechanism of adiponectin on human ovarian cancer cells. Methods: The level of adiponectin, adiponectin receptor-1, caspase-3 and bcl-2 in the serum and ascites of the patients were measured with enzyme-linked immunosorbent assay (ELISA), qPCR and Western blotting. The human ovarian cancer cell lines (Caov3 and SKOV3) were enumerated using 3(4, 5-dimethylthiazol-2-yl)-2, 5-tetrazolium bromide (MTT) assay. Western blotting was also used to determine the levels of p-Akt, p-ERK and cyclin B. Results: Serum and ascite levels of adiponectin were significantly higher in ovarian cancer patients than in healthy patients (p < 0.05). Expression of adiponectin in the serum and ascites of patients in F/GO stage IV was remarkably higher than in earlier stages (p < 0.05). The proliferative effect of adiponectin on ovarian cells was dose-dependent. Adiponectin treatment significantly increased the expression of cyclin B in Caov3 and SKOV3, and reduced the levels of caspase-3 and bcl-2. Inhibitors of PI3K and MEK pathways significantly reduced the proliferation of attenuated Caov3 and SKOV3 by up-regulating cyclin B upon adiponectin treatment (p < 0.05), and thus alleviated the inhibitory effect of adiponectin on the expressions of caspase-3 and bcl-2. Conclusion: The findings demonstrate that adiponectin promotes proliferation of the cells via the PI3K/Akt and Raf/MEK/ERK pathways, and also provide new insights into ovarian cancer treatmment.