RESUMO
@#[摘 要] 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-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-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。
RESUMO
Objective:To establish a colon cancer cell line which overexpressing LINC01018 stably and study its biological characteristics.Methods:The expression of LINC01018 in HCoEpiC and HT-29 cells were detected by real time fluorescence quantitative polymerase chain reaction (qRT-PCR). HT-29 cells were infected with LINC01018 overexpression lentivirus to screen and establish HT-29 cell lines which overexpressing LINC01018 stably. The effect of LINC01018 on the proliferation, invasion and migration of HT-29 cells were detected by cell counting kit-8 (CCK-8) assay and Transwell assay separately. The expression of CDK6 and matrix metalloproteinase-2 (MMP-2) in HT-29 cells was detected by Western blot.Results:The expression of LINC01018 in HT-29 cells was significantly lower than that in the human colonic epithelial cells (HCoEpiC). HT-29-L18 cell lines which overexpressing LINC01018 stably was screened successfully. Overexpression of LINC01018 significantly inhibited the cell proliferation, invasion and migration, and reduced the protein expression of CDK6 and MMP-2 in HT-29 cells.Conclusions:The expression of LINC01018 was decreased abnormally in colon cancer cells. Up-regulation of LINC01018 expression can inhibit the proliferation, invasion and migration of colon cancer cells, which may be related to CDK6 and MMP-2.
RESUMO
Objective:To study the specific mechanism of LINC01018 involved in the pathogenesis of colon cancer.Methods:The expression of LINC01018 in colon cancer tissues and cells and normal colon tissues and cells were detected by real time fluorescence quantitative polymerase chain reaction (qRT-PCR). HT-29 cell line which overexpresses LINC01018 stably was established. RNA binding protein immunoprecipitation (RIP) assay was used to detect the interaction between LINC01018 and E2F1 protein. Dual luciferase assay was used to detect the regulatory effect of E2F1 on CDK6 promoter. The expression of E2F1 or CDK6 was up-regulated in HT-29 cell line which overexpresses LINC01018, then the proliferation, invasion and migration of HT-29 cells and the expression of CDK6 and matrix metalloproteinase-2 (MMP-2) in HT-29 cells were detected by cell counting method (CCK-8) assay, Transwell assay and Western blot.Results:The expression of LINC01018 was abnormally low in colon cancer tissues and cells. The result of RIP assay showed that LINC01018 interacted with E2F1 protein. The result of dual luciferase assay showed that E2F1 protein could enhance the efficiency of CDK6 promoter, and E2F1 had a positive regulatory effect on CDK6. Overexpression of LINC01018 could attenuate the positive regulatory effect of E2F1 on CDK6. Up-regulation of E2F1 or CDK6 expression could attenuate the effects of LINC01018 overexpression on the proliferation, invasion, migration and expression of CDK6 and MMP-2 in HT-29 cells.Conclusions:The expression of LINC01018 was abnormally low in colon cancer tissues and cells. LINC01018 may regulate the proliferation, invasion and migration of HT-29 cells through E2F1/CDK6/MMP-2 axis, and participate in the pathogenesis of colon cancer.