m6A识别蛋白HuR调控lncRNA TRG-AS1抑制结直肠癌生长的机制研究

目的 探讨N6-甲基腺苷（m6A）识别蛋白人类抗原R(HuR)调控长链非编码RNA T细胞受体γ位点反义RNA 1(lncRNA TRG-AS1)对结直肠癌（CRC）生长的影响。方法 比色法检测CRC患者的癌组织、癌旁组织及正常结肠上皮细胞NCM460及CRC细胞HCT116、SW480、LOVO中m6A含量；实时荧光定量PCR(qPCR)检测TRG-AS1表达；Western blot检测HuR蛋白表达。将HCT116细胞分为Ct组、OE-NC组、OE-HuR组、si-NC组、si-HuR组、siHuR+pcDNA组、si-HuR+pcDNA-TRG-AS1组，CCK-8法检测细胞增殖；平板克隆实验检测细胞克隆形成能力；流式细胞术检测细胞凋亡率；划痕愈合实验检测细胞迁移；Transwell检测细胞侵袭；裸鼠体内移植瘤实验观察肿瘤生长情况；采用甲基化RNA免疫共沉淀（MeRIP）检测TRG-AS1上是否存在m6A位点；RNA pull-down实验和RNA免疫共沉淀（RIP）检测TRG-AS1与HuR蛋白的相互作用。结果 在CRC组织和细胞中，HuR蛋白、TRG-AS1高表达，m6A含...

The mechanism of m6A recognition protein HuR inhibiting the growth of colorectal cancer by regulating lncRNA TRG-AS1

Objective To investigate the influence of N6-methyladenosine (m6A) recognition protein human antigen R (HuR) on the growth of colorectal cancer (CRC) by regulating long non-coding RNA T cell receptor gamma locus antisense RNA 1 (lncRNA TRG-AS1). Methods The content of m6A in cancer tissue, paracancer tissue and normal colon epithelial cells NCM460 and CRC cells HCT116, SW480 and LOVO were detected by colorimetric method. The expression of TRG-AS1 was detected by real-time fluorescence quantitative PCR (qPCR). The expression of HuR protein was detected by Western blot assay. HCT116 cells were divided into the Ct group, the OE-NC group, the OE-HuR group, the si-NC group, the si-HuR group, the si-HuR + pcDNA group and the si-HuR+ pcDNA-TRG-AS1 group. CCK-8 assay was applied to detect cell proliferation. Plate cloning assay was used to detect the ability of cells to form clones. Flow cytometry was applied to detect apoptosis. Scratch-healing assay was applied to detect cell migration. Transwell assay was used to detect cell invasion. In vivo tumor xenograft experiment was used to observe tumor growth in nude mice. Methylated RNA immunoprecipitation (MeRIP) was applied to detect the presence of m6A sites on TRG-AS1. RNA co-immunoprecipitation (RIP) and RNA pull-down experiments were used to demonstrate the interaction of TRG-AS1 with HuR protein. Results In CRC tissue and cells, HuR protein and TRG-AS1 were highly expressed, and m6A content was decreased. In HCT116 cells, the expression levels of HuR protein and TRG-AS1 were the highest, and the m6A content was the lowest (P<0.05), therefore, HCT116 cells were selected as the research object. Compared with the si-NC group, the expression levels of HuR protein and TRG-AS1 decreased in the si-HuR group, and the m6A content increased (P<0.05). Compared with the OE-NC group, expression levels of HuR protein and TRG-AS1 increased in the OE-HuR group, and the m6A content decreased (P<0.05). Compared with the si-HuR group and the si-HuR+pcDNA group, there were no significant differences in changes of HuR protein and m6A content in the si-HuR+pcDNA-TRG-AS1 group, but the expression of TRG-AS1 increased (P<0.05). The down-regulation of HuR could inhibit HCT116 cell proliferation, migration, invasion and growth of transplanted tumor in vivo, and promote cell apoptosis, while up-regulation of HuR showed the opposite trends. The overexpression of TRG-AS1 attenuated the inhibitory effect of silencing HuR on HCT116 cell proliferation, migration, invasion, in vivo xenograft growth, and the promotion of apoptosis. There was m6A site on TRG-AS1, and TRG-AS1 could interact with HuR protein. Conclusion Silencing the m6A recognition protein HuR can inhibit the proliferation, migration, invasion of HCT116 cells and promote cell apoptosis by inhibiting the expression of TRG-AS1.