目的：筛选果蝇Zeste 基因增强子同源物2（EZH2）基因上游miRNA及lncRNA，分析其在胃癌细胞中的表达并验证其间的靶向关系，探讨它们对胃癌细胞增殖、迁移和凋亡的影响。方法：通过ENCORI、miRDB 和Target Scan 数据库查询并分析、筛选 EZH2 上游 miRNA（has-miR-450b-5p），ENCORI 数据库和 DAINA 数据库筛选 has-miR-450b-5p 上游 lncRNA（lncRNA NEAT1），预测hsa-miR-450b-5p、lncRNA NEAT1 与EZH2 之间的结合位点，双荧光素酶报告基因实验验证hsa-miR-450b-5p 与lncRNA NEAT1 的结合关系。采用qPCR 和WB法检测lncRNA NEAT1 和EZH2 在正常胃黏膜细胞（GES-1）与胃癌细胞（MGC-803、SGC-7901 和MKN-28）中的表达量。按转染物的不同将MGC-803 和SGC-7901 细胞分为hsa-miR-450b-5p-mimic 组、mimic-NC 组、si-NEAT1 组和si-NC 组，转染36~48 h 后qPCR 法验证过表达及敲减效果；通过qPCR、WB 法检测观察过表达hsa-miR-450b-5p 对细胞中lncRNA NEAT1 和EZH2 mRNA、蛋白表达的影响，以及敲减lncRNA NEAT1 对hsa-miR-450b-5p 和EZH2 mRNA表达的影响；CCK-8法、划痕愈合实验和流式细胞术分别检测敲减EZH2或敲减lncRNA NEAT1对细胞增殖、迁移和凋亡能力的影响。结果：生物信息学分析筛选获得EZH2上游miRNA 和lncRNA 为has-miR-450b-5p和lncRNA NEAT1，双荧光素酶报告基因实验验证了两者间存在靶向关系。lncRNA NEAT1 和EZH2 mRNA、蛋白在胃癌细胞中均呈高表达（均P<0.05）。与mimic-NC 组相比，hsa-miR-450b-5p-mimic 组MGC-803、SGC-7901 细胞中miR-450b-5p水平均显著升高，而EZH2 mRNA、蛋白和lncRNA NEAT1的表达量均显著降低（P<0.05 或P<0.01）；与si-NC 组相比，si-NEAT1 组MGC-803、SGC-7901 细胞中lncRNA NEAT1 和EZH2 mRNA 的表达量均显著降低（均P<0.01），SGC-7901 细胞中hsa-miR-450b-5p 表达量显著升高（P<0.05）。敲减EZH2或敲减lncRNA NEAT1后，MGC-803、SGC-7901 细胞的增殖、迁移能力均显著降低（均P<0.01）。结论：lncRNA NEAT1 和EZH2在胃癌细胞中均呈高表达，lncRNA NEAT1可通过hsa-miR-450b-5p促进EZH2的表达并提高胃癌MGC-803 和SGC-7901 细胞的增殖和迁移能力。

Objective: To screen the upstream miRNAs and lncRNAs of EZH2 gene, analyze their expressions in gastric cancer cells,verify the targeting relationship between them, and discuss their effects on the proliferation, migration and apoptosis of gastric cancer cells. Methods: The upstream miRNA (has-miR-450b-5p) of EZH2 was queried, analyzed and screened by ENCORI, miRDB and Target Scan databases, and the upstream lncRNA (lncRNA NEAT1) of hsa-miR-450b-5p was screened by ENCORI database and DAINA database. The binding sites between hsa-miR-450b-5p, lncRNA NEAT1 and EZH2 were predicted. Dual-luciferase reporter assay was used to verify the binding relationship between hsa-miR-450b-5p and lncRNA NEAT1. The expression levels of lncRNA NEAT1 and EZH2 in normal gastric epithelial cells (GES-1) and gastric cancer cells (MGC-803, SGC-7901 and MKN-28) were detected by qPCR and WB. MGC-803 and SGC-7901 cells were divided into the hsa-miR-450b-5p-mimic group, the mimic-NC group,the si-NEAT1 group and the si-NC group according to different transfections, and the overexpression and knockdown effects were verified by qPCR 36~48 h after transfection. qPCR and WB were used to detect and observe the effects of overexpression of hsa-miR-450b-5p on the protein expressions of lncRNA NEAT1 and EZH2mRNA, in cells, and the effect of knockdown of lncRNA NEAT1 on the expressions of hsa-miR-450b-5p and EZH2 mRNA. CCK-8 method, scratch healing assay and flow cytometry were used to detect the effects of knockdown of EZH2 or knockdown of lncRNA NEAT1 on cell proliferation, migration, and apoptosis, respectively. Results: The upstream miRNA and lncRNA of EZH2 obtained through bioinformatic analysis and screening were has-miR-450b-5p and lncRNA NEAT1, and the targeting relationship between the two was verified by double luciferase reporter gene assay. lncRNA NEAT1 and EZH2 mRNA 、protein were highly expressed in gastric cancer cells (both P<0.05). Compared with the mimic-NC group,the levels of miR-450b-5p in MGC-803 and SGC-7901 cells in the hsa-miR-450b-5p-mimic group increased significantly, while the expressions of EZH2 mRNA, protein and lncRNA NEAT1 decreased significantly (P<0.05 or P<0.01). Compared with the si-NC group, the expressions of lncRNA NEAT1 and EZH2 mRNA in MGC-803 and SGC-7901 cells decreased significantly in the si-NEAT1 group (both P<0.01), and the expression of hsa-miR-450b-5p in SGC-7901 cells increased significantly (P<0.05). The proliferation and migration abilities of MGC-803 and SGC-7901 cells were significantly reduced after knockdown of EZH2 or lncRNA NEAT1 (both P<0.01). Conclusion: lncRNA NEAT1 and EZH2 were highly expressed in gastric cancer cells, and lncRNA NEAT1 promoted the expression of EZH2 and improved the proliferation and migration abilities of gastric cancer MGC-803 and SGC-7901 cells through hsa-miR-450b-5p.

国家自然科学基金项目（No. 82174146）；河南省科技攻关项目（No. 212102310639）