LncRNA-HOTTIP促进肺癌发生发展的作用及机制研究

Effects and mechanisms of LncRNA-HOTTIP on tumorigenesis and progression of lung cancer

目的探讨长链非编码RNA-HOTTIP在肺癌发生发展中的作用和机制。方法通过芯片技术检测肺癌和癌旁组织中的LncRNA表达谱并以Real-time PCR对结果进行验证,分析其表达水平与临床病理因素之间的关系;通过CCK-8实验检测HOTTIP对肺癌细胞增殖的影响、Annexin V/PI双染法检测HOTTIP对肺癌细胞凋亡的影响、Western blot检测HOTTIP对增殖和凋亡相关蛋白表达的影响。结果HOTTIP在肺癌组织和细胞中表达异常增高,其表达水平与肿瘤大小、淋巴结转移和TNM分期正相关;功能学实验显示HOTTIP在体外可促进肺癌细胞增殖,而沉默其表达则能诱导凋亡;沉默HOTTIP表达可促进bax和caspase-3活性片段增多,抑制bcl-2表达,进而诱导凋亡。miR-137与HOTTIP存在潜在结合位点,并且miR-137表达水平与HOTTIP呈反比。结论 HOTTIP可能通过竞争性结合miR-137,减弱后者的抑癌作用,进而促进肺癌细胞发生发展。

Objective To investigate the role of HOTTIP in lung development and tumorigenesis. Methods The long noncoding RNA expression profiling in lung cancer is examined using Agilent Mouse lncRNA Microarray v2. 0 and verified using realtime PCR. The expression and location of HOTTIP in lung cancer tissues and cells were examined using realtime PCR and in situ hybridization,respectively. The relationship between HOTTIP expression and clinicopathological features as well as miR-137 expression were also analyzed in lung cancer tissues. The effects of HOTTIP on cell proliferation and apoptosis were examined using CCK-8 assay and Annexin V/PI staining assay,respectively. The effects of HOTTIP on the expression of proliferation-and apoptosis-related proteins were examined by Western blot. Results HOTTIP expression was up-regulated in lung cancer,and its expression was positively associated with tumor size,lymph metastasis and TNM staging. Functional studies showed that HOTTIP over-expression promoted cell proliferation,while HOTTIP silencing induced cell apoptosis. Silencing HOTTIP expression could promote the increase of bax and caspase-3 active fragments,inhibit the expression of bcl-2 and induce apoptosis. In addition,the basestar software showed that sequence of HOTTIP contain potential binding sites for miR-137,and HOTTIP expression is negative correlated with miR-137 expression in lung cancer tissues. Conclusion HOTTIP acts as an endogenous competing sponge of miR-137,which may attenuate the antitumor activities of miR-137 and promote lung tumorigenesis and development.