CircRNA SLAIN1竞争性结合miR-200b调控自噬参与人肺腺癌化疗耐药的分子机制研究

Chemoresistance remains a major obstacle constraining the clinical application of this treatment for lung adenocarcinoma （LAD）. Autophagy， a regulated process occurring in all types of eukaryotic cells， functions primarily as a pro-survival mechanism leading to chemoresistance. On the previous basis of establishment of docetaxel-resistant lung adenocarcinoma cell lines， our study investigated that activated autophagy contributed to chemoresistance of LAD cells. Downregulated-miR-200b-dependent upregulation of ATG12 led to increased autophagic activity involved in chemoresistance of LAD cells. However， the molecular mechanism responsible for downregulated miR-200b is not fully understood and need to be elucidated. CircRNA chip data and function experiments indicated that ciR-SLAIN1 increased expression of ATG12. Bioinformatics analyses proved the existence of binding site between ciR-SLAIN1 and miR-200b. Based on previous research achievement， with RNA immunoprecipitation， RNA-FISH， luciferase activity assay and other molecular biological technologies， the aim of this study is to reveal the mechanism that ciR-SLAIN1 in upregulation of ATG12 by base paring with miR-200b，by which led to activation of autophagy and chemoresistance of LAD cells. Our work will provide a novel strategy for individualized treatment and reversing chemoresistance in combating LAD.

化疗耐药是限制肺腺癌临床疗效的重要障碍。自噬是广泛存在于真核细胞中的生命现象，与化疗耐药密切相关。我们在前期建立肺腺癌多西他赛耐药细胞的基础上已证实自噬水平升高为肺腺癌化疗耐药形成的重要因素，miR-200b低表达所致的下游靶基因ATG12过度上调可促进自噬，参与化疗耐药形成，但miR-200b下调的机制仍不明确。circRNA芯片及功能验证发现ciR-SLAIN1可通过上调ATG12表达促进自噬。生物信息学分析提示ciR-SLAIN1与miR-200b之间存在可能的竞争性结合。本课题拟在前期研究基础上，采用RNA免疫共沉淀、RNA原位杂交、荧光素酶报告基因等实验方法从体内外水平证实ciR-SLAIN1通过与miR-200b竞争性结合，阻断miR-200b对其靶基因ATG12的抑制作用促进自噬，参与肺腺癌化疗耐药形成的分子机制，为逆转肺腺癌化疗耐药探索新的临床策略。

化疗耐药是限制肺腺癌临床疗效的重要障碍。自噬是广泛存在于真核细胞中的生命现象，与化疗耐药密切相关。我们在前期建立肺腺癌多西他赛耐药细胞的基础上已证实自噬水平升高为肺腺癌化疗耐药形成的重要因素，miR-200b低表达所致的下游靶基因ATG12过度上调可促进自噬，参与化疗耐药形成，但miR-200b下调的机制仍不明确。circRNA芯片及功能验证发现过表达ciR-SLAIN1可诱导自噬，促进肺腺癌化疗耐药形成。生物信息学分析提示ciR-SLAIN1与miR-200b之间存竞争性结合。本课题在前期研究基础上，采用RNA免疫共沉淀、RNA原位杂交、双荧光素酶报告基因等实验方法证实ciR-SLAIN1通过与miR-200b竞争性结合，阻断miR-200b对其靶基因ATG12的抑制作用促进自噬，参与肺腺癌化疗耐药形成的分子机制，为逆转肺腺癌化疗耐药探索新的临床策略。