目的：探讨miR-125a-5p通过调控Bcl-2相关永生基因4（Bcl-2-associated athanogene 4，BAG4）的表达抑制胃癌细胞 迁移和侵袭的分子机制。方法：选用2014年1月至2015年12月兰州大学第一医院手术切除的82例胃癌组织标本及配对的癌旁 组织以及人胃癌细胞系MGC803、BGC823、SGC7901、HGC27及人胃黏膜上皮细胞（GES-1），qPCR法检测胃癌组织、癌旁组织及 胃癌细胞系中miR-125a-5p的表达水平。分别将miR-125a-5p mimic、miR-125a-5p inhibitor、（si-BAG4）siRNA-BAG4及阴性对照 质粒转染至胃癌细胞，划痕愈合实验和Transwell侵袭实验分别检测miR-125a-5p/BAG4信号轴对胃癌细胞迁移和侵袭能力的影 响。WB检测胃癌细胞中BAG4蛋白的表达。荧光素酶报告基因实验验证miR-125a-5p和BAG4之间的靶向调控关系。结果： miR-125a-5p在胃癌组织和细胞系中均低表达（均P<0.01）。miR-125a-5p的表达与患者的性别（P=0.953）、年龄（P=0.772）、肿瘤 部位(P=0.867)、组织学分级（P=0.745）和肿瘤大小（P=0.088）无相关性 ，与胃癌患者的 T 分期（P=0.003）、N 分期（P=0.001）、 M分期（P=0.027）和TNM分期（P=0.035）显著相关，差异有统计学意义。miR-125a-5p低表达是胃癌患者总生存时间的独立危险 因素。过表达miR-125a-5p显著抑制胃癌细胞的迁移和侵袭能力（均P<0.01）。敲降BAG4可逆转miR-125a-5p inhibitor对胃癌细 胞迁移和侵袭能力的抑制作用。荧光素酶报告基因实验证实miR-125a-5p可与BAG4 3'非翻译区（untranslated regions，UTR）结 合抑制其表达。结论：miR-125a-5p通过靶向下调BAG4的表达水平进而抑制胃癌细胞的迁移和侵袭。的表达抑制胃癌细胞 迁移和侵袭的分子机制。方法：选用2014年1月至2015年12月兰州大学第一医院手术切除的82例胃癌组织标本及配对的癌旁 组织以及人胃癌细胞系MGC803、BGC823、SGC7901、HGC27及人胃黏膜上皮细胞（GES-1），qPCR法检测胃癌组织、癌旁组织及 胃癌细胞系中miR-125a-5p的表达水平。分别将miR-125a-5p mimic、miR-125a-5p inhibitor、（si-BAG4）siRNA-BAG4及阴性对照 质粒转染至胃癌细胞，划痕愈合实验和Transwell侵袭实验分别检测miR-125a-5p/BAG4信号轴对胃癌细胞迁移和侵袭能力的影 响。WB检测胃癌细胞中BAG4蛋白的表达。荧光素酶报告基因实验验证miR-125a-5p和BAG4之间的靶向调控关系。结果： miR-125a-5p在胃癌组织和细胞系中均低表达（均P<0.01）。miR-125a-5p的表达与患者的性别（P=0.953）、年龄（P=0.772）、肿瘤 部位(P=0.867)、组织学分级（P=0.745）和肿瘤大小（P=0.088）无相关性 ，与胃癌患者的 T 分期（P=0.003）、N 分期（P=0.001）、 M分期（P=0.027）和TNM分期（P=0.035）显著相关，差异有统计学意义。miR-125a-5p低表达是胃癌患者总生存时间的独立危险 因素。过表达miR-125a-5p显著抑制胃癌细胞的迁移和侵袭能力（均P<0.01）。敲降BAG4可逆转miR-125a-5p inhibitor对胃癌细 胞迁移和侵袭能力的抑制作用。荧光素酶报告基因实验证实miR-125a-5p可与BAG4 3'非翻译区（untranslated regions，UTR）结 合抑制其表达。结论：miR-125a-5p通过靶向下调BAG4的表达水平进而抑制胃癌细胞的迁移和侵袭。

Objective: To explore the molecular mechanism of miR-125a-5p suppressing the migration and invasion of gastric cancer cells by regulating expression of Bcl-2-associated athanogene 4 (BAG4) gene. Method: A total of 82 pairs of gastric cancer tissues and corresponding para-cancer tissues were obtained from gastric cancer patients who received curative surgery at the First Hospital of Lanzhou University during January 2014 to December 2015. Human gastric cancer cell lines (MGC803, BGC823, SGC7901, HGC27) and human gastric epithelium cell line (GES-1) were also collected for this study. Real-time fluorescent quantitative PCR (qPCR) method was used to detect the expression level of miR-125a-5p in gastric cancer tissues, para-cancer tissues and gastric cancer cell lines. miR-125a-5p mimics, miR-125a-5p inhibitor, si-BAG4 (siRNA-BAG4) and negative control plasmids were transiently transfected into gastric cancer cells, respectively. The effect of miR-125a-5p/BAG4 signaling axis on migratory and invasive ability of gastric cancer cells was determined by Wound healing assay and Transwell invasion assay, respectively. WB was used to detect BAG4 protein expression in gastric cancer cells. The targeted regulatory relationship between miR-125a-5p and BAG4 was determined by Luciferase reporter gene assay. Result: miR-125a-5p was down-regulated in gastric cancer tissues and gastric cancer cell lines. The expression level of miR-125a-5p was not correlated with gender (P=0.953), age (P=0.772), tumor location (P=0.867), histological grade (P=0.745) and tumor size (P=0.088) of gastric cancer patients, but significantly correlated with T stage (P=0.003), N stage (P=0.001), M stage (P=0.027) and TNM stage (P=0.035) in gastric cancer patients, and the differences were statistically significant. Low expression of miR-125a-5p was an independent risk factor for overall survival of gastric cancer patients. miR-125a-5p significantly inhibited the migration and invasion of gastric cancer cells (all P<0.01). Knockdown BAG4 could reverse the inhibitory effect of miR-125a-5p inhibitor on migration and invasion of gastric cancer cells. Luciferase reporter gene assay validated that miR[1]125a-5p could bind with BAG4 3'UTR (Untranslated Regions) to suppress its expression. Conclusion: miR-125a-5p inhibits the migration and invasion of gastric cancer cells by down-regulating the expression level of BAG4.

国家自然科学基金资助项目（No. 82060527）；兰州大学第一医院院内基金项目（ldyyyn2019-02），2020年度兰州市科技发展指导性计 划项目(No. 2020-ZD-66)