miR-21低表达对垂体瘤细胞系RC-4BC增殖、凋亡的影响及与PTEN靶向关系OACSTPCD

Objective To investigate the effects of low expression of microRNA-21(miR-21)on the proliferation and apoptosis of pituitary tumor cell line RC-4BC,and to analyze its targeting relationship with phosphatase and tensin homolog deleted on chromosome ten(PTEN).Methods RC-4BC cells in the logarithmic growth phase were divided into two groups.Cells in the silence group were transfected with miR-21 inhibitor,while cells in the negative control group were transfected with inhibitor negative control NC-inhibitor.RT-PCR was used to detect the mRNA of miR-21 and PTEN.CCK8 assay was used to observe the cell proliferation ability of the two groups(expressed by OD value),plate cloning assay was used to observe the cell colony formation ability of the two groups(expressed by colony formation number),flow cytome-try was used to observe the apoptosis rates of the two groups and to observe the cell cycle distribution.Single cell suspension was prepared from RC-4BC cells,and miR-21 mimics or NC-mimics were co-transfected into RC-4BC cells with PTEN-WT or PTEN-MUT,respectively.After transfection,the cells were labeled as the miR-21 mimics+PTEN-WT group,NC-mim-ics+PTEN-WT group,miR-21 mimics+PTEN-MUT group,and NC-mimics+PTEN-MUT group,respectively.The dual lu-ciferase reporter gene assay was used to verify the targeting relationship between miR-21 and PTEN.Results The relative expression levels of miR-21 and PTEN mRNA in RC-4BC cells of the silence group were 0.30±0.08 and 2.89±0.14,re-spectively,while those in the negative control group were 1.01±0.02 and 0.99±0.03,respectively,with statistically sig-nificant differences(all P<0.05).The OD values of RC-4BC cells of the silence group were lower than those of the nega-tive control group at 24,48,and 72 h(all P<0.05).The number of colony formation of RC-4BC cells in the silence group was smaller than that in the negative control group(P<0.05).The apoptosis rate of RC-4BC cells in the silence group was higher than that in the negative control group(P<0.05).The proportions of cells in the G0/G1 phase and S phase were 65.65%±7.82%and 19.25%±3.70%,in the silence group,respectively,versus 45.62%±5.03%and 35.72%±4.67%,in the negative control group,respectively,with statistically significant differences(all P<0.05).The relative luciferase activity of the miR-21 mimics+PTEN-WT group,NC-mimics+PTEN-WT group,miR-21 mimics+PTEN-MUT group,and NC-mimics+PTEN-MUT group was 0.39±0.07,1.02±0.03,1.01±0.04,and 1.00±0.03,respectively,and significant difference was found in the relative luciferase activity between the miR-21 mimics+PTEN-WT group and the other groups(all P<0.05).Conclusion Silencing miR-21 can inhibit the proliferation and promote apoptosis of RC-4BC cells in pi-tuitary tumor cell line,and its mechanism may be related to the targeted regulation of PTEN gene.