circHIAT1靶向miR-522-3p对肺癌细胞A549凋亡和放射敏感性的影响

Effect of circHIAT1 targeting miR-522-3p on apoptosis and radiosensitivity of lung cancer cell A549

目的探讨环状RNA海马丰富基因转录蛋白1(circHIAT1)对肺癌细胞A549凋亡和放射敏感性的影响及分子机制。方法回顾性选取2017年1月至2019年5月应急总医院收治的37例肺癌患者的癌组织及癌旁组织标本;将pcDNA、pcDNA-circHIAT1、si-NC、si-circHIAT1转染至A549细胞中,计为pcDNA组、pcDNA-circHIAT1组、si-NC组、si-circHIAT1组;将pcDNA-circHIAT1分别与miR-NC、miR-522-3p共转染至A549细胞中,计为pcDNA-circHIAT1+miR-NC组、pcDNA-circHIAT1+miR-522-3p组。实时荧光定量聚合酶链反应(RT-qPCR)检测circHIAT1和miR-522-3p的表达水平;流式细胞术检测细胞凋亡;细胞克隆集落形成实验检测细胞放射敏感性;双荧光素酶报告实验检测circHIAT1和miR-522-3p的靶向关系。结果与癌旁组织比较,肺癌组织中circHIAT1表达水平(0.43±0.04 vs.1.00±0.07)降低,miR-522-3p表达水平(2.88±0.21 vs.1.00±0.07)升高,差异均有统计学意义(P<0.05)。circHIAT1过表达后肺癌细胞A549的凋亡率升高[(21.11±2.12)%vs.(7.77±0.54)%],差异有统计学意义(P<0.05)。不同剂量射线照射后,pcDNA-circHIAT1组细胞存活分数降低,差异有统计学意义(P<0.05)。miR-522-3p与WT-circHIAT1转染的细胞荧光素酶活性降低(0.32±0.03 vs.0.99±0.07),差异有统计学意义(P<0.05),miR-522-3p与MUT-circHIAT1转染的细胞荧光素酶活性差异无统计学意义(1.00±0.06 vs.1.02±0.08,P>0.05)。与pcDNA-circHIAT1+miR-NC组比较,pcDNA-circHIAT1+miR-522-3p组细胞凋亡率降低[(12.83±1.22)%vs.(22.53±2.18)%],差异有统计学意义(P<0.05);不同剂量射线照射后,pcDNA-circHIAT1+miR-522-3p组细胞存活分数升高,差异有统计学意义(P<0.05)。结论CircHIAT1过表达通过靶向下调miR-522-3p促进肺癌细胞A549凋亡,提高了其放射敏感性。

Objective To explore the effect and molecular mechanism of Circular RNA hippocampus abundant transcript 1(circHIAT1)on lung cancer cell A549 apoptosis and radiosensitivity.Methods Thirty-seven cases of lung cancer patients'cancer tissues and paracancerous tissue samples from January 2017 to May 2019 were retrospectively selected.pcDNA,pcDNA-circHIAT1,si-NC,and si-circHIAT1 were transfected into A549 cells and counted as pcDNA group,pcDNA-circHIAT1 group,si-NC group,si-circHIAT1 group.pcDNA-circHIAT1 was co-transfected with miR-NC and miR-522-3p into A549 cells,and counted as pcDNA-circHIAT1+miR-NC group and pcDNA-circHIAT1+miR-522-3p group.Real-time fluorescence quantitative PCR(RT-qPCR)was used to detect the expressions of circHIAT1 and miR-522-3p;flow cytometry was used to detect apoptosis;colony formation experimental was used to detect cell radiosensitivity;dual luciferase report experiment to detect the targeting relationship between circHIAT1 and miR-522-3p.Results Compared with adjacent tissues,the expression level of circHIAT1(0.43±0.04 vs.1.00±0.07)in lung cancer tissues was decreased,and the expression level of miR-522-3p(2.88±0.21 vs.1.00±0.07)was increased,the differences were statistically significant(P<0.05).After circHIAT1 overexpression,the apoptosis rate of lung cancer cell A549 was increased[(21.11±2.12)%vs.(7.77±0.54)%],the difference was statistically significant(P<0.05);after different doses of radiation,the survived score of pcDNA-circHIAT1 group was decreased,the difference was statistically significant(P<0.05).The luciferase activity of cells transfected with miR-522-3p and WT-circHIAT1 was decreased(0.32±0.03 vs.0.99±0.07),the difference was statistically significant(P<0.05),and the luciferase activity of cells transfected with miR-522-3p and MUT-circHIAT1 had no significant difference(1.00±0.06 vs.1.02±0.08,P>0.05).Compared with the pcDNA-circHIAT1+miR-NC group,the apoptosis rate of the pcDNA-circHIAT1+miR-522-3p group was reduced[(12.83±1.22)%vs.(22.53±2.18)%],the difference was statistically significant(P<0.05);after different doses of radiation,the cell survival score of the pcDNA-circHIAT1+miR-522-3p group was increased,the difference was statistically significant(P<0.05).Conclusion Overexpression of circHIAT1 can promote the apoptosis of lung cancer cell A549 by targeting down-regulation of miR-522-3p and improve its radiosensitivity.