miR-196a调控HOXA5对人胃癌细胞MGC-803侵袭转移的影响及机制研究

摘要

Objective To investigate the expression level of miR-196a in gastric cancer( GC) tissues and cell lines, to study the effect of inhibition or up-regulation of miR-196a expression on GC cells migration and invasion, and to find out the possible target gene. Methods Real-time quantitative PCR was performed to detect the relative expression of miR-196a in GC cell lines and tissues. MiR-196a inhibitors or mimics were transfected into MGC-803 cells to down-regulate or up-regulate miR-196a expression, and Real-time quantitative PCR was used to test the transfection efficiency. Wound healing, transwell and MTT assays were performed to detect the effect of miR-196a on GC cells migration, invasion and proliferation. Bioinformatics and Western blotting analysis were performed to investigate the target genes that could be regulated by miR-196a. Results This study showed that miR-196a was highly expressed both in GC samples and cell lines compared with their corresponding normal tissues and cell lines (approximately 28 folds, P<0�01). Transfection of miR-196a inhibitors or mimics could significantly decrease ( 53%, P<0�01) or increase ( approximately 8 folds, P<0�01) its expression in MGC-803 cells, respectively. And down-regulation of miR-196a expression could inhibit MGC-803 cells migra-tion, invasion and proliferation by down-regulating HOXA5 expression. Conclusion Up-regulated miR-196a could promote gastric cancer cells migration and invasion by inhibiting the expression of HOXA5, which may affect the development of gastric cancer.%目的：检测miR-196a在人胃癌组织及细胞系中的表达，探讨抑制或过表达miR-196a对胃癌细胞侵袭转移能力的影响，以及其可能作用的靶基因。方法通过实时定量PCR技术检测胃癌组织及细胞系中miR-196a的表达水平，通过转染miR-196a inhibitors或mimics抑制或上调其表达，并通过定量PCR检测转染效率。利用划痕迁移实验、Transwell侵袭实验和MTT实验检测上调或下调 miR-196a 水平对 MGC-803细胞的迁移、侵袭和增殖能力的影响。采用生物信息学及Western blotting方法验证miR-196a对靶基因HOXA5的调控机制。结果相对于正常胃黏膜组织及细胞，胃癌组织和细胞系中miR-196a的表达水平显著上调（上调约28倍，P＜0�01），MGC-803细胞中转染miR-196a inhibitors或mimics能显著抑制（下降了53％，P＜0�01）或上调（上调约8倍，P＜0�01） miR-196a表达水平。抑制miR-196a表达能降低MGC-803细胞的迁移、侵袭和增殖能力，而上调其表达则相反。 miR-196a能够负性调控HOXA5的表达。结论胃癌组织及细胞系中miR-196a的表达上调可能通过抑制HOXA5的表达显著提高胃癌细胞的侵袭转移能力，促进胃癌的发生、发展。