miR-4500通过转录后下调LIN28B表达抑制乳腺癌细胞的迁移和增殖

The miR-4500 inhibits migration and proliferation of breast cancer cells by down-regulating LIN28B expression after transcription

目的观察微小RNA(miRNA,miR)-4500通过转录后下调LIN-28同系物B(lin-28 homolog B,LIN28B)基因表达对乳腺癌细胞HCC1937迁移和增殖的抑制作用。方法采用实时定量聚合酶链反应(real-time PCR)检测乳腺癌细胞系(MB-MDA-468、MCF7、SKBR3、HCC1937)中miR-4500的表达。以miR-4500表达最低的乳腺癌细胞系(HCC1937)为对象,分别转染miR-4500模拟物和miR-NC,命名为miR-4500组和miR-NC组。real-time PCR检测转染效果。Transwell实验和噻唑蓝(MTT)实验检测转染后乳腺癌细胞迁移和增殖能力。生物信息学软件预测和双荧光素酶报告实验验证miR-4500的靶基因。real-time PCR和Western blot检测乳腺癌细胞中靶基因的表达。结果miR-4500在乳腺癌细胞系的表达显著低于正常乳腺上皮细胞(P<0.05),并在HCC1937细胞中表达最低(P<0.01)。miR-4500组miR-4500的表达(11.60±1.08)显著高于miR-NC组(1.22±0.48),差异有统计学意义(P<0.01)。与miR-NC组比较,miR-4500组细胞迁移和增殖能力均显著降低(P<0.05)。生物信息学软件显示miR-4500的靶基因是LIN28B。双荧光素酶报告实验证明miR-4500可靶向结合LIN28B基因(P<0.05)。与miR-NC组比较,miR-4500组HCC1937细胞中LIN28B的表达显著降低(P<0.05)。结论LIN28B基因是miR-4500的靶基因,miR-4500可通过转录后下调LIN28B基因表达抑制乳腺癌细胞HCC1937的迁移和增殖能力。

Objective To observe the inhibitory effect of microRNA-4500(miR-4500)on the migration and proliferation of breast cancer cell line HCC1937 by post-transcriptional down-regulation of LIN-28 homolog B(LIN28B)gene expression.Methods The expression of miR-4500 in breast cancer cell lines(MB-MDA-468,MCF7,SKBR3,HCC1937)was detected by real-time quantitative polymerase chain reaction(PCR).The breast cancer cell line HCC1937 with the lowest miR-4500 expression was used as the subject,and was transfected with miR-4500 mimics(miR-4500 group)or miR-NC(miR-NC group).Real-time PCR was used to detect transfection efficiency.Transwell assay and thiazolyl blue(MTT)assay were used to detect the migration and proliferation of breast cancer cells.Bioinformatics software and the double luciferase report experiment were used to predict and verify the target gene of miR-4500,respectively.Real-time PCR and Western blot were used to detect the mRNA and protein levels of target genes in breast cancer cells.Results The expression of miR-4500 in breast cancer cell lines was significantly lower than that in normal breast epithelial cells(P<0.05),and it was the lowest in HCC1937 cells(P<0.01).The expression of miR-4500 in miR-4500 group was significantly higher than that in miR-NC group(11.60±1.08 vs 1.22±0.48,P<0.01).Compared with miR-NC group,the cell migration ability and the cell proliferation ability was significantly decreased in miR-4500 group(P<0.05).Bioinformatics software showed that the target gene of miR-4500 is LIN28B.The dual luciferase reporter assay demonstrated that miR-4500 targeted the LIN28B gene(P<0.05).Compared with miR-NC group,the expression of LIN28B in the HCC1937 cells was significantly decreased in miR-4500 group(P<0.05).Conclusion The LIN28B gene is a target gene of miR-4500,and miR-4500 can inhibit the migration and proliferation of breast cancer cells HCC1937 by down-regulating the expression of LIN28B gene after transcription.