Effects of miR-451 on the biological behavior of colorectal carcinoma cell line SW620

Objective To explore the effects of human miR-451 on the proliferation,apoptosis and invasive ability of colon cancer cell line SW620.Methods Four groups were designed in the present experiment,i.e.,cells were transfected with 100nmol/L of miR-451 mimics in miR-451 mimics group,with 100nmol/L of negative control in negative control(NC) group,with Lipo 2000 alone in blank control group,and without transfection of either Lipo2000 or miRNA in control group.The expression of miR-451 was measured by real-time RT-PCR 24h after transfection,and proliferation of cells was examined by using the Cell Counting Kit-8 at respective time of 24,48,72 hours after transfction.The apoptotic rate was assessed by flow cytometry(FCM) and invasive ability was determined by Transwell assay.The effect of miR-451 mimics on the expression of macrophage migration inhibitory factor(MIF) protein was measured by immunofluorescent and Western blot assay.Results Twenty-four hours after transfection,an increase in expression of miR-451 was noted in miR-451 mimics group(67.96±13.33) when compared with NC group,in which the expression of miR-451 was defined as 1(P0.01).In comparison with the other groups,miR-451 mimics group showed a significant inhibition of proliferation at 48 and 72 hours after transfection(P0.01),but no significant change in apoptotic rate was found at 48 hour after transfection(P0.05).Immunofluorescent assay showed that MIF positive rate of miR-451 mimics group(23.9%±14.9%) was decreased when compared with that of NC group(53.5%±14.1%),blank transfection group(45.2%±19.8%) and blank control group(59.3%±22.2%)(F=7.356,P0.01).Transwell assay illustrated that the invasive ability in miR-451 mimics group(37.4±6.1 invasive cells per field) was lower than that in negative control group(55.6±3.6 invasive cells per field),blank transfection group(60.8±7.4 invasive cells per field) and blank control group(61.6±8.6 invasive cells per field,P0.01).Conclusion Up-regulation of miR-451 expression may inhibit the bioactivity of colon cancer cells,and it may be attributed to the inhibition of MIF expression.