microRNA-139-5p及其靶基因Notch1在结直肠癌中的作用

目的：探讨microRNA-139-5p（miR-139-5p）在结直肠癌中的表达及其对结直肠癌细胞转移和侵袭的影响。方法：用荧光定量PCR方法检测miR-139-5p在结直肠癌组织与不同结直肠癌细胞株中的表达变化；用Boyden小室分析和伤口愈合实验检测miR-139-5p转染及miR-139-5p抑制对结直肠癌细胞转移和侵袭能力的影响；生物信息学方法预测miR-139-5p的靶基因，并采用荧光素酶报告基因实验验证，Western blot方法检测miR-139-5p转染对靶基因表达的影响。结果：与各自的正常对照组比较，结直肠癌组织与结直肠癌细胞系中miR-139-5p表达均明显降低（P<0.05）。结直肠癌DLD1细胞和HCT116细胞转染miR-139-5p后，转移与侵袭能力均明显降低（均P<0.05），而miR-139-5p抑制剂处理后，两种细胞的的侵袭能力均明显增强（均P<0.05）。生物信息学预测显示，Notch1是miR-139-5p的靶基因，且得到荧光素报告实验结果证实。Western blot结果显示，转染miR-139-5p后，结直肠癌DLD1细胞和HCT116细胞中Notch1蛋白表达均明显下调（均P<0.05）。结论：miR-139-5p可能通过调节Notch1的表达而抑制肿瘤细胞的转移和侵袭，而下调的miR-139-5p可能在结直肠癌的发生发展中起了重要作用。

Role of microRNA-139-5p and its target gene Notch1 in colorectal cancer

Objective: To investigate the effect of microRNA-139-5p (miR-139-5p) expression in colorectal cancer and its influence on migration and invasion ability of colorectal cancer cells.Methods: The expression alteration of miR-139-5p in colorectal cancer tissue and different colorectal cancer cell lines were detected by using fluorescent quantitative PCR. The influence of miR-139-5p transfection or miR-139-5p inhibitor treatment on migration and invasion ability of colorectal cancer cells were detected by Boyden chamber assay and wound healing assay. The target gene of miR-139-5p was predicted by bioinformatics analysis and was identified by luciferase reporter assay, and then the influence of miR-139-5p transfection on its target gene expression was determined by Western blot analysis.Results: The miR-139-5p mRNA expressions in both colorectal cancer tissue and colorectal cancer cell lines were significantly decreased compared with corresponding control (all P<0.05). The migration and invasion ability in colorectal cancer DLD1 and HCT116 cells were significantly decreased after miR-139-5p transfection and were significantly increased after miR-139-5p inhibitor treatment (all P<0.05). Bioinformatics analysis showed that Notch1 was the potential target gene of miR-139-5p which was then identified by luciferase reporter assay. Western blot results showed that Notch1 protein expressions in DLD1 and HCT116 cells were significantly down-regulated after miR-139-5p transfection (both P<0.05).Conclusion: MiR-139-5p may inhibit the migration and invasion of cancer cells through regulating its target gene Notch1, so the down-regulated miR-139-5p may play an important role in the occurrence and development colorectal cancer.