Characterization of Apoptosis in a Breast Cancer Cell Line after IL-10 Silencing

Background: Breast cancer is affected by the immune system in that different cytokines play roles in its initiationand progression. Interleukin-10 (IL-10), an anti-inflammatory cytokine, is an immunosuppressive factor involved intumorigenesis. The present study was conducted to investigate the gene silencing effect of a small interference RNA(siRNA) targeting IL-10 on the apoptotic pathway in breast cancer cell line. Methods: The siRNA targeting IL-10 anda glyceraldehyde 3-phosphate dehydrogenase (GAPDH) clone were introduced into MDA-MB-231 cells. Real-timePCR assays were used to determine IL-10 and GAPDH gene expression levels, in addition to those for protein kinaseB (AKT), phosphoinositide 3-kinase (PI3K), B-cell lymphoma 2 (Bcl2), caspase-3 and caspase-9 genes related toapoptosis. Results: Inhibition of IL-10 by the siRNA accelerated apoptosis and was accompanied by significantincrease in caspase-3 and caspase-9 and a significant decrease in PI3K, AKT and Bcl2 expression levels compared tothe non-transfected case. Conclusions: In conclusion, the production of IL-10 may represent a new escape mechanismby breast cancer cells to evade destruction by the immune system. IL-10 gene silencing causes down regulation of bothPI3K/AKT and Bcl2 gene expression and also increases the Bbc3, BAX caspase3, and caspase 3 cleavage expressionlevels. IL–10 might represent a promising new target for therapeutic strategies.