长链非编码RNA XLOC_012366在表观遗传学介导的肺癌转移抑制中的机制研究

At present, there are many anti-tumor studies on methyltransferase inhibitors, but the role and mechanism of metastasis in lung cancer have not been elucidated. Our previous study showed that 5-Aza had significantly inhibited the migration and invasion of highly metastatic non-small cell lung cancer cells. We also found that 5-Aza regulate the EMT / MET balance on non-small cell lung cancer. We further screened and identified lncRNA XLOC_012366 that was differentially expressed in lung cancer cells under the treatment with 5-Aza. We think that lncRNA XLOC_012366 is involved in regulation of lung cancer cell EMT / MET balance and inhibition of lung cancer metastasis by 5-Aza, and hypothesize that, by means of lncRNA XLOC_012366 inhibition, 5-Aza can inhibit lung cancer metastasis by regulating EGFR-PTEN-PI3K/AKT signal pathway mediated by miR-608. This study aims to explore the mechanism of 5-Aza in the inhibition of lung cancer metastasis by studying lncRNA XLOC_012366 expression inhibited by 5-Aza, and regulation of EGFR-PTEN-PI3K/AKT signal pathway mediated by miR-608. We hope the study can provide a new therapeutic target for the treatment of metastatic therapy for non-small cell lung cancer, and a new application thought for epigenetic therapy.

甲基转移酶抑制剂在肺癌转移方面的作用和机制尚未明确。我们前期研究发现甲基化抑制剂5-Aza能抑制高转移性非小细胞肺癌（NSCLC）细胞的迁移和侵袭能力，并发现5-Aza可调控NSCLC细胞EMT/MET平衡，进而我们筛选出肺癌细胞5-Aza处理前后差异性表达的lncRNA XLOC_012366。我们推测lncRNA XLOC_012366参与了5-Aza调控肺癌细胞EMT/MET平衡，提出“5-Aza通过抑制lncRNA XLOC_012366，调节miR-608介导的EGFR-PTEN-PI3K/AKT信号通路抑制肺癌转移”。本课题通过检测5-Aza抑制lncRNA XLOC_012366表达，调节上述信号通路以论证该假说，探究5-Aza抑制肺癌转移具体机制，为非小细胞肺癌转移抑制治疗提供新的治疗靶点，也为表观遗传治疗提供新的思路。

本课题前期研究中我们成功筛选出肺癌细胞经5-Aza处理后差异性表达的LncRNA XLOC_012366，推测LncRNA XLOC_012366参与了5-Aza调控肺癌细胞EMT/MET平衡，提出“5-Aza通过抑制LncRNA XLOC_012366调节miR-608介导的EGFR-PI3K/AKT信号通路抑制肺癌转移”的假说。因此，探索5-Aza介导的LncRNA XLOC_012366抑制肺癌转移的具体分子机制在新型肿瘤治疗方向中具有重要的研究意义。本项目中我们收集肺癌患者的肺癌组织及癌旁组织，探讨LncRNA XLOC_012366在组织标本中的表达及其与患者生存率的关系。其次建立转染LncRNA XLOC_012366、miR-608、EGFR的过表达与敲低的肺癌细胞系，探讨三者在肺癌细胞中的功能表达及三者相互作用具体机制，也同时探索三者相互作用对PI3K/AKT的表达情况。最后，在动物实验上，观察植瘤体积与分子表达。经过研究，课题内容实验已完成，我们发现通过抑制LncRNA XLOC_012366能抑制肺癌的增殖与转移，同时也发现miR-608与EGFR-PI3K/AKT在肺癌中的机制，最终我们探索出的具体机制是表观遗传介导的LncRNA XLOC_012366通过靶向调节miR-608介导的EGFR-PI3K/AKT信号通路抑制肺癌转移，LncRNA XLOC_012366作为ceRNA调节miRNA-608介导肺癌转移。通过本研究发现，我们认为LncRNA XLOC_012366在肺癌中显著表达，同时也揭示表观治疗在肺癌治疗中作用机制的其中一个关键过程，同时为肺癌转移抑制治疗提供新的治疗靶点，为表观遗传治疗提供新的应用思路。