miRNA-101通过靶向CDK8调控结肠癌细胞侵袭和Wnt/β-catenin通路活化

miRNA-101 Regulates Colon Cancer Cell Invasion and Wnt/β-catenin Pathway Activation Through Targeting CDK8

目的探讨miRNA-101(miR-101)通过靶向CDK8对结肠癌细胞侵袭和Wnt/β-catenin通路激活的影响。方法采用q RT-PCR和Western blot测定结肠癌组织、癌旁正常组织及五种结肠癌细胞株中miR-101和CDK8的表达。双荧光素酶报告实验测定其相互作用关系。通过miR-101 mimic、pBabeCDK8转染调控CDK8表达并测定其对肿瘤细胞侵袭和Wnt/β-catenin激活的影响。结果与癌旁正常组织相比,miR-101在结肠癌组织中表达水平显著降低,而CDK8的表达显著增加。双荧光素酶报告实验证实miR-101可直接与CDK8 3'UTR的结合位点作用调节荧光素酶的活性。转染miR-101 mimic组细胞的侵袭能力比阴性对照组和CDK8组明显下降。转染miR-101 mimic后TOP/FOP荧光素酶活性显著降低,β-catenin的蛋白表达也出现下降。CDK8过表达载体转染能显著减弱miR-101 mimic对荧光素酶活性和β-catenin蛋白表达的作用。结论 miRNA-101可通过靶向CDK8调控结肠癌细胞侵袭和Wnt/β-catenin通路活化。

Objective To investigate the effect of miRNA-101（miR-101） on the invasion and Wnt/β-catenin pathway activation in colon cancer cells through targeting CDK8. Methods q RT-PCR and Western blot were used to detect the expression of miR-101 and CDK8 in colon cancer tissues,adjacent normal tissues and five colon cancer cell lines. Dual luciferase reporter assay was used to determine whether miR-101 could directly bind to the 3＇UTR region of CDK8. CDK8 expression was regulated through miR-101 mimic and/or p Babe-CDK8 transfection,and its effects on tumor cell invasion and Wnt/β-catenin activation were detected. Results Compared with adjacent normal tissues,the expression level of miR-101 in colon cancer tissues was significantly decreased,while the expression of CDK8 increased significantly. Dual luciferase reporter assay confirmed that miR-101 could bind directly to the 3＇UTR region of CDK8 and regulate its expression. The invasion ability of colon cancer cells transfected with miR-101 mimic was significantly lower than those in negative control group and CDK8 overexpression group. The transfection of miR-101 mimic resulted in a significant decrease of TOP/FOP luciferase activity and β-catenin protein expression. However,CDK8 overexpression vector transfection could significantly inhibit the effect of miR-101 mimic. Conclusion miRNA-101 could regulate colon cancer cell invasion and Wnt/β-catenin pathway activation through targeting CDK8.