Yuan Kai-Tao, Li Bao-Xia, Yuan Yu-Jie, Tan Min, Tan Jin-Fu, Dai Wei-Gang, Feng Wei-Dong, Zuo Ji-Dong
1 Department of Gastrointestinal Surgery, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong, China.
Technol Cancer Res Treat. 2018 Jan 1;17:1533033818806499. doi: 10.1177/1533033818806499.
Gastric cancer is a deadly disease. Some microRNAs are involved in tumor invasion and metastasis. Underexpression of miR-375 has been correlated with tumorigenesis, treatment resistance, and poor prognosis. In this study, we first analyzed the profiles and prognostic values of miR-375 expression in gastric cancer tissues from a public database, and the expression level of miR-375 in gastric cancer samples and gastric cancer cell lines was then analyzed by quantitative real- time polymerase chain reaction. Significant underexpression of miR-375 was seen in all the gastric cancer samples compared to paired paracarcinoma tissues, and the expression level of miR-375 in the gastric cancer cell lines was negatively associated with the cell migration ability. A Cell proliferation (CCK-8) assay was performed to examine cell viability. Overexpression of miR-375 suppressed the proliferation of gastric cancer cells. A Western blot analysis was carried out to test protein expression. Overexpression of miR-375 inhibited autophagy through the AKT/ mammalian target of rapamycin signaling pathway. MiR-375 regulated invasion and migration via AKT/ mammalian target of rapamycin pathway-mediated epithelial-to-mesenchymal transition. Wound healing and migration assays were used to determine the motility of gastric cancer cells. A gastric cancer xenograft nude mouse model was used for an in vivo efficacy evaluation. Overexpression of miR-375 significantly suppressed cell proliferation in the established gastric cancer xenograft nude mouse model. Our results demonstrate that increasing the expression level of miR-375 suppresses proliferation in vitro and in vivo, and they provide a mechanistic and applicable rationale for the future clinical evaluation of miR-375 in gastric cancer treatment. Our findings provide not only new information about the molecular mechanism of microRNAs in regulating invasion and migration in gastric cancer but also a theoretical principle for a potential targeted therapy for gastric cancer.
胃癌是一种致命疾病。一些微小RNA参与肿瘤侵袭和转移。miR-375的低表达与肿瘤发生、治疗耐药性及不良预后相关。在本研究中，我们首先从公共数据库分析了胃癌组织中miR-375表达的谱和预后价值，然后通过定量实时聚合酶链反应分析了胃癌样本和胃癌细胞系中miR-375的表达水平。与配对的癌旁组织相比，所有胃癌样本中均观察到miR-375的显著低表达，且胃癌细胞系中miR-375的表达水平与细胞迁移能力呈负相关。进行细胞增殖（CCK-8）试验以检测细胞活力。miR-375的过表达抑制了胃癌细胞的增殖。进行蛋白质印迹分析以检测蛋白质表达。miR-375的过表达通过AKT/雷帕霉素哺乳动物靶标信号通路抑制自噬。miR-375通过AKT/雷帕霉素哺乳动物靶标通路介导的上皮-间质转化调节侵袭和迁移。采用伤口愈合和迁移试验来测定胃癌细胞的运动能力。使用胃癌异种移植裸鼠模型进行体内疗效评估。miR-375的过表达在已建立的胃癌异种移植裸鼠模型中显著抑制细胞增殖。我们的结果表明，提高miR-375的表达水平在体外和体内均抑制增殖，并且它们为miR-375在胃癌治疗中的未来临床评估提供了一个机制性和适用性的理论依据。我们的发现不仅提供了关于微小RNA调节胃癌侵袭和迁移分子机制的新信息，也为胃癌潜在靶向治疗提供了理论原则。
