Abstract: Objective  To investigate the effects of interleukin-6 (IL-6) on the expressions of B-cell lymphoma-2 (Bcl-2), CyclinD1 (CyclinD1) and vascular endothelial growth factor (VEGF) in epithelial ovarian cancer SKOV3 cells. Methods  The optimal concentration of IL-6 was determined by treating SKOV3 cells with IL-6 of diverse concentrations. In addition to IL-6 of the optimal concentration, AG490 of diverse concentrations were also used. The proliferation and apoptosis of cells, and the mRNA and protein expressions of Bcl-2, CyclinD1, and VEGF were detected by MTT, flow cytometry, RT-PCR and Western blotting. Results  IL-6 promoted proliferation and inhibited apoptosis of the cells(P<0.01), and increased the mRNA and protein expressions of Bcl-2, CyclinD1 and VEGF (P<0.01). The effects of IL-6 (0, 10, 20ng/mL) were  in a concentration-dependent way. There were significant differences between 48h and 24h (P<0.01). AG490 inhibited proliferation and promoted apoptosis of the cells(P<0.01), and depressed the mRNA and protein expressions of Bcl-2, CyclinD1 and VEGF (P<0.01). The effects of AG490 (0, 20, 40, 80μmol/L) were  in a concentration-dependent way. There were no significant differences between 48h and 24h (P>0.05). Conclusion  IL-6 promotes the gene transcription and expressions of Bcl-2, CyclinD1 and VEGF by promoting the phosphorylation of STAT3, and then enhances the proliferation and inhibits apoptosis of ovarian cancer cells.

Key words: Interleukin-6, B-cell lymphoma-2, Vascular endothelial growth factor, Ovarian cancer, CyclinD1