Effect of miR-1231 on proliferation, apoptosis and invasion of colon cancer stem cells

Yan Li-kun; Li Wei; Yao Jian-feng; Mao Zhi-jun

doi:10.3969/j.issn.2095-4344.2016.45.009

Abstract：BACKGROUND:Previous studies have found that miR-1231 is down-regulated in colon cancer stem cel s (CCSCs), but the effect of miR-1231 on CCSCs remains unclear. <br> OBJECTIVE:To explore the effect of miR-1231 on the proliferation, apoptosis and invasion of CCSCs (CD133+CD44+). <br> METHODS:CD133+CD44+cel s and CD133-CD44-cel s were separated from SW1116 cel s by immunomagnetic bead separation. The expression level of miR-1231 in CD133+CD44+and CD133-CD44-cel s was detected by qRT-PCR. miR-1231-overexpressing CD133+CD44+cel s were transfected with miR-1231 mimics or miR-control by lipofection transfection. The effects of miR-1231 on CD133+CD44+cel proliferation, apoptosis and invasion were investigated by MTT, flow cytometry and Transwel assays, respectively. In addition, the expression levels of Ki67, Bax, Bcl-2, MMP-2 and MMP-9 protein in miR-1231-overexpressing CD133+CD44+cel s and control cel s were detected by western blot. <br> RESULTS AND CONCLUSION:CD133+CD44+and CD133-CD44-cel s were obtained by the immunomagnetic bead separation. The expression level of miR-1231 in CD133+CD44+cel s was significantly lower than that in CD133-CD44-cel s. miR-1231 suppressed CD133+CD44+cel proliferation and invasion, but promoted the apoptosis in these cel s. Western blot analysis showed that miR-1231-overexpressing CD133+CD44+cel s had obvious decreases in Ki67, Bcl-2, MMP-2 and MMP-9 protein expression and a significant increase in Bax protein expression compared with control cel s. Al these results further confirm that miR-1231 inhibits the proliferation and invasion but promotes the apoptosis in CD133+CD44+cel s. These findings suggest that miR-1231 can be a suppressor of CCSCs, which offers a novel potential therapeutic target for CCSCs and colon cancer.