目的：探讨长基因间非编码 RNA（long intergene non-coding RNA，LINC）01018 是否通过抑制 miR-297 调控胃癌 HGC-27细胞的增殖、凋亡及放射敏感性。方法：收集于青海省第五人民医院接受手术的胃癌患者（21例）及化疗抵抗胃癌患者 （19例）的癌组织和癌旁组织，以qPCR检测胃癌组织、化疗抵抗胃癌组织和胃癌HGC-27细胞中LINC01018、miR-297的表达。双 荧光素酶报告基因实验验证 LINC01018 与 miR-297 之间的靶向关系。在 HGC-27 细胞中转染 LINC01018 过表达质粒 pcDNA[1]LINC01018或miR-297抑制剂，或共转染pcDNA-LINC01018和miR-297模拟物，以qPCR检测验证细胞转染效果。MTT和克隆 形成实验检测转染后HGC-27细胞的增殖活力与克隆形成能力，流式细胞术检测转染后HGC-27细胞的凋亡率，克隆形成实验检 测各组转染后HGC-27细胞的放射敏感性，WB实验检测细胞中Ki67、cleaved-caspase3、pro-caspase3蛋白的表达。结果：与癌旁 组织或胃正常黏膜上皮细胞GES-1相比，胃癌组织、化疗抵抗胃癌组织和胃癌HGC-27细胞中LINC01018呈低表达、miR-297呈 高表达（均P<0.01）。LINC01018与miR-297存在靶向结合关系，LINC01018负向调控miR-297的表达。过表达LINC01018或敲 减miR-297可抑制HGC-27细胞的增殖活力与克隆形成能力、降低细胞存活率，促进细胞的凋亡、下调Ki67和pro-caspase3蛋白表 达水平、上调cleaved-caspase3蛋白表达水平、提高HGC-27细胞的放射敏感性（均P<0.01）。共转染pcDNA-LINC01018和miR[1]297模拟物可逆转过表达LINC01018对HGC-27细胞的所有上述作用，尤其可逆转其对HGC-27细胞的放射增敏作用（P<0.05或P<0.01）。结论：LINC01018通过下调miR-297表达抑制胃癌HGC-27细胞增殖而促进凋亡和增强细胞的放射敏感性，该作用与 Ki67和caspase3的表达变化有关。

Objective: To investigate whether long intergene non-coding RNA (LINC) 01018 regulates the proliferation, apoptosis and radiosensitivity of gastric cancer HGC-27 cells by inhibiting miR-297. Methods: The cancer tissues and para-cancerous tissues from gastric cancer patients (21 cases) who underwent surgery or chemo-resistant gastric cancer patients (19 cases) in the Fifth People's Hospital of Qinghai Province were collected, and the expressions of LINC01018 and miR-297 in gastric cancer tissues, chemo-resistant gastric cancer tissues and gastric cancer HGC-27 cells were detected by qPCR. Dual luciferase reporter gene assay was used to verify the targeting relationship between LINC01018 and miR-297. The LINC01018 overexpression plasmid pcDNA-LINC01018, miR-297 inhibitor, or pcDNA-LINC01018+miR-297 mimic was transfected into HGC-27 cells, and the transfection efficiency was verified by qPCR. MTT and Clone formation experiment were employed to assess the proliferation viability and the clone formation ability of HGC-27 cells after transfection. The apoptosis rate of HGC-27 cells was evaluated by Flow cytometry, and the radiosensitivity of HGC-27 cells after transfection in each group was determined with Clone formation experiment. WB was used to detect the protein expressions of Ki67, cleaved-caspase3 and pro-caspase3 in the cells. Results: Compared with para-cancerous tissues or normal gastric mucosal epithelial GES-1 cells, the expression level of LINC01018 decreased while the expression level of miR-297 increased in gastric cancer tissues, chemo-resistant gastric cancer tissues and gastric cancer HGC-27 cells (all P<0.01). LINC01018 had a targeted binding relationship with miR-297, and LINC01018 negatively regulated the expression of miR-297. LINC01018 overexpression or miR-297 knockdown inhibited the proliferation viability, clone formation and cell survival of HGC-27 cells, down-regulated the protein expression level of Ki67 and pro-caspase3, but promoted the apoptosis and radiosensitivity of HGC-27 cells as well as up-regulated the expression level of cleaved-caspase3 protein (all P<0.01). Co-transfection of pcDNA-LINC01018 and miR-297 mimic could reverse all the above-mentioned effects of LINC01018 overexpression on HGC-27 cells, especially its radio-sensitization effect on HGC-27 cells (P<0.05 or P<0.01). Conclusion: LINC01018 inhibits the proliferation of gastric cancer HGC-27 cells by down-regulating the expression of miR-297 to promote apoptosis and enhance the radiosensitivity of cells, which may be related to the expression of Ki67 and caspase3.

青海省医药卫生科技项目指导性计划课题（No. 2018-Wjzdx-46）