TMEM59结合ATG16L1诱导自噬参与小细胞肺癌多药耐药的机制研究

Small cell lung cancer (SCLC) is characterized by the poor prognosis since the patients rapidly develop resistance to chemotherapy. Our previous study demonstrated that TMEM59 (Transmembrane protein 59) was upregulated in H69AR，a chemoresistant SCLC cell line，by a cDNA microarray. Downregulation of TMEM59 sensitized cells to chemotherapeutic drugs and suppressed autophagy in refractory SCLC cells. We have reported that autophagy could promote SCLC multi-drug resistance, and there were reports showed that TMEM59 directly interacted with ATG16L1 and then activated autophagy. We conducted further study which revealed that increasing autophagy was diminished by knockdown of ATG16L1 in H69AR，meanwhile chemoresistance was inhibited. Therefore, we propose a hypothesis that TMEM59 interacting with ATG16L1 promote drug resistance by regulating autophagy in SCLC. Chemoresistant SCLC cell lines, tumor xenograft models and SCLC tissues will be used to investigate the role of TMEM59 in SCLC chemoresistance. We will further explore the potential molecular mechanism that TMEM59 interacting with ATG16L1 enhance SCLC chemoresistance by autophagy. This study will enrich the mechanisms of drug resistance and it might provide a potentially novel target to reverse chemoresistance of SCLC.

小细胞肺癌（SCLC）多药耐药是患者预后不良的重要原因之一。我们前期利用表达谱芯片发现跨膜蛋白TMEM59与小细胞肺癌耐药相关，沉默TMEM59表达可降低细胞对化疗药物的耐药性，并抑制自噬水平。我们前期已证实自噬可促进小细胞肺癌的耐药性，结合文献报道TMEM59与自噬关键调节因子ATG16L1直接结合诱导自噬，我们进一步在小细胞肺癌耐药细胞中下调ATG16L1的表达，发现可抑制细胞自噬、提高对化疗药物的敏感性。由此提出本项目的研究假说：TMEM59结合ATG16L1，通过自噬途径参与小细胞肺癌多药耐药的调节。本项目拟利用小细胞肺癌耐药细胞模型、实验动物、临床标本，明确TMEM59对小细胞肺癌多药耐药的影响，并进一步明确TMEM59结合ATG16L1通过诱导自噬促进耐药性。通过本研究，进一步丰富小细胞肺癌多药耐药的分子机制，为小细胞肺癌临床治疗提供潜在的靶点。

小细胞肺癌（SCLC）多药耐药是患者预后不良的重要原因之一。本项目利用表达谱芯片发现跨膜蛋白TMEM59与小细胞肺癌耐药相关，沉默TMEM59表达可降低细胞对化疗药物的耐药性。本课题采用小细胞肺癌耐药细胞模型、实验动物、临床标本，明确TMEM59参与小细胞肺癌的增殖及多药耐药。研究发现ATG16L1影响小细胞肺癌细胞自噬。进一步探索，发现TMEM59通过ATG16L1影响小细胞肺癌自噬，进一步影响小细胞肺癌的多药耐药性并不稳定，因此转而利用Co-IP、质谱分析筛选TMEM59结合的蛋白明确TMEM59下游信号分子，发现丙酮酸激酶PKM2与TMEM59相互结合。课题组前期研究表明糖酵解影响小细胞肺癌多药耐药。目前通过GST-pull down明确TMEM59与PKM2是否直接结合，进一步明确TMEM59结合PKM2通过糖酵解促进小细胞肺癌的增殖及耐药性。通过本研究，进一步丰富小细胞肺癌肿瘤进展的分子机制，为逆转小细胞肺癌进展提供潜在的治疗靶点。