The Expression And Functional Investigation Of Long Non-coding RNA XIST In Breast Cancer Cells MCF-7

Objective:To investigate the expression and function of lncRNA XIST in breast cancer cells MCF-7.Methods:The expression of XIST in human normal breast epithelial cells(MCF 10A)and human breast cancer cell lines(MCF-7 and and MDA-MB-231)was detected by qRT-PCR.Transient transfection technique was used to overexpress XIST in MCF-7cells.MTT assay,wound healing test,transwell cell migration and invasion assays were used to detect the changes of proliferation,migration and invasion of MCF-7 cells in which XIST was overexpressed.And we constructed MCF-7 cells with stably overexpression of XIST,then MTT assay,clone formation assay,wound healing test,transwell cell migration and invasion assays were used to verified the effects of XIST overexpression on MCF-7 cells.Bioinformatics and qRT-PCR were used to predict and detect the changes of the expression of microRNA which has potential binding sites of XIST.Results:1.The expression level of XIST in breast cancer cells MCF-7 was much lower than that in normal breast epithelial cells MCF 10A(P <0.001),while the expression level of miR-130b-3p in breast cancer cells MCF-7 was significantly higher than that in normal breast epithelial cells MCF-10A(P < 0.001).2.Overexpression of XIST in MCF-7 cells significantly inhibited cell proliferation(P <0.001),promoted cell migration and invasion.And the result of qRT-PCR showed that the expression of miR-130b-3p was significantly reduced after XIST was overexpressed in MCF-7 cells(P <0.01).3.The binding site of miR-130b-3p was found in XIST sequence,and the expression of XIST and miR-130b-3p were negatively correlated in breast cancer cells MCF-7.Conclusion:The expression of XIST and miR-130b-3p in breast cancer cells MCF-7 were negatively correlated,and the overexpression of XIST could significantly inhibit the proliferation of MCF-7 cells and promote the migration and invasion of MCF-7 cells.