Oncostatin M promotes proliferation of ovarian cancer cells through signal transducer and activator of transcription 3

Oncostatin M (OSM), a pleiotropic cytokine, has been shown to have distinctive effects in different tissues. In ovarian carcinoma, it is commonly co-expressed together with its receptors but its precise role and the underlying molecular mechanism governing its activity remains unclear. The aim of the present study was to investigate the function of the recombinant human OSM (rH-OSM) in human ovarian cancer. The study demonstrated that rH-OSM promotes the proliferation of SKOV3 ovarian cancer cells. Western blot analysis showed that phosphorylated-signal transducer and activator of transcription 3 (p-STAT3), phosphorylated-extracellular signal-regulated protein kinase 1/2 (p-ERK1/2) and p-p38 protein levels increased in the cell lines treated with rH-OSM. Proliferation in SKOV3 cells induced by rH-OSM was suppressed by inhibitors of p-p38 or p-ERK1/2. Western blot analysis showed that p-STAT3 protein levels decreased in SKOV3 cells treated with inhibitors of p-p38 prior to treatment with rH-OSM. Also, p-STAT3 levels did not increase in cells treated with inhibitors of ERK1/2 prior to treatment with rH-OSM. Cell proliferation was moderately increased, and p-ERK1/2 and p-p38 protein expression were similarly affected in STAT3-RNAi knocked-down SKOV3 cells treated with rH-OSM compared to the control group. The data demonstrate that the growth-promoting activity of rH-OSM may be mediated through different signaling pathways. ERK1/2 and p38 proteins regulate STAT3 expression in SKOV3 cells, while STAT3 may be pivotal to the proliferation of SKOV3 cells in vitro.