miR-651-3p suppresses the expression of immunosuppressive factors IL-10 and TGFβ1 in breast cancer / 免疫学杂志

ABSTRACT

This study was aimed to investigate the expression of miR-651-3p in breast cancer and its role in regulating the expression of immunosuppressive factors IL-10 and TGFβ1 as well as the apoptosis level of breast cancer cells.qRT-PCR was used to detect the expression level of miR-651-3p in MCF-7 cells.miR-651-3p-over-expressng/-silencing plasmids and SP2-silencing plasmid were used to transfect MCF-7 cells.The expression levels of SP2,IL-10 and TGFβ1 were detected by Western blot assays.The apoptosis level of MCF-7 cells was detected by flow cytometry.The binding between miR-651-3p and SP2 was verified by dual luciferase gene report,and the binding of SP2 to IL-10 and TGFβ1 promoter region was verified by ChIP assay.Our results showed that miR-651-3p was down-regulated in breast cancer cells(P<0.05).The over-expression of miR-651-3p and the knockdown of SP2 significantly down-regulated the expression levels of IL-10 and TGFβ1 and promoted the apoptosis of breast cancer cells,while silenced miR-651-3p had the opposite effect.miR-651-3p binds to the SP2-3'-UTR end and down-regulates its expression.Based on the silencing of miR-651-3p,the silencing of SP2 can significantly reduce the influence of silenced miR-651-3p on the expression of IL-10 and TGFβ1 and apoptosis level in breast cancer cells.SP2 promotes the expression levels of IL-10 and TGFβ1 by binding to their promoters,respectively.Taken together,down-regulated miR-651-3p in breast cancer inhibited the expression of SP2 by binding to its 3'-UTR region,reduced the up-regulation effect of SP2 on the expression of IL-10 and TGFβ1,thus inhibiting the expression of immunosuppressive factors IL-10 and TGFβ1 and promoting apoptosis in breast cancer cells.