Effects of miR-206/miR-1 on Breast Cancer Stem Cell Proliferation and the Mechanism / 中国医科大学学报

ABSTRACT

Objective To investigate the effects of up?regulated miR?206/miR?1 on the proliferation of breast cancer stem cells and the effect mech?anism. Methods Breast cancer stem cells(BCSCs)were isolated from breast cancer cell line MCF?7 by fluorescence?activated cell sorting. Cells in the experiment were divided into the blank control group,the negative control group,the miR?206 group and the miR?1 group. The BCSCs were transfected by negative control mimic,hsa?miR?206mimic and hsa?miR?1mimic in all groups except the blank control group. MiR?206and miR?1 expression levels as well as the transcription factor EVI?1 gene were detected by real time PCR. The expression levels of the transcription factor EVI?1 protein were detected by Western blot. MTT method was used to detect the effects of miR?206 and miR?1 on the proliferation of BCSCs. Results The BCSCs(CD44+/CD24-/low cells)isolated from MCF?7 cell lines were successfully cultured in serum?free medium for subsequent studies. After transfection of hsa?miR?206mimic and hsa?miR?1mimic for 48 hours,miR?206and miR?1relative expression levels increased. EVI?1mRNA ex?pression levels significantly decreased. The results of Western blot and MTT showed that up?regulated expression levels of miR?206 and miR?1 could significantly reduce the expression of EVI?1 protein and inhibited the proliferation of BCSCs. The differences in levels of miR?206,miR?1 and EVI?1 protein were statistically significant(P<0.05). Conclusion Up?regulated miR?206 and miR?1 expression can inhibit the proliferation ability of BCSCs,which may be related to the down?regulation of EVI?1.