m5C修饰调控非小细胞肺癌 EGFR-TKI耐药的机制研究

EGFR-TKI耐药是非小细胞肺癌(NSCLC)治疗中面临的严峻问题。表观遗传学在肿瘤耐药中扮演重要角色，RNA 5-甲基胞嘧啶 (m5C) 修饰是表观遗传学研究的前沿领域和热点。迄今关于m5C在肿瘤耐药中的作用尚不清楚。本团队前期发现：吉非替尼耐药NSCLC细胞中mRNA m5C甲基转移酶NSUN2表达显著上调，而下调NSUN2和m5C结合蛋白ALYREF表达能逆转吉非替尼耐药。据此我们提出假说：RNA m5C修饰异常是诱导EGFR-TKI耐药的重要原因，m5C修饰可通过调控耐药基因mRNA加工代谢影响其表达，进而诱导耐药。为验证这一假说，我们拟从细胞、模式动物及临床水平，综合分子和细胞生物学、表观组学和生物信息学等学科交叉手段，探讨m5C修饰对EGFR-TKI耐药的影响，明确m5C修饰调控的靶基因及机制，阐明靶基因与耐药及NSCLC预后的关系，为逆转EGFR-TKI耐药提供新策略。

Epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKI) resistance is a big concern during the therapy for non-small-cell lung cancer (NSCLC) patients. Accumulating evidence suggests that epigenetic alterations play vital roles in the cancer drug resistance. As a new research frontier of epigenetics, the effect of RNA 5-methylcytosine (m5C) modification in the regulation of cancer drug resistance is still unclear. We previously found that expression of the methyltransferase of mRNA m5C modification, NSUN2, was significantly increased in gefitinib-resistant NSCLC cells; whereas RNA interference of NSUN2 and the m5C-binding protein ALYREF reversed the drug resistance. Based on these findings, we hypothesize that abnormal m5C modification on RNA plays an important role in EGFR-TKI resistance through the regulation of drug resistance-associated genes. To validate this hypothesis, we will determine the role of m5C modification in EGFR-TKI resistance and identify the targeted genes that contribute to EGFR-TKI resistance with multidisciplinary approaches of molecular and cell biology, epigenetics and bio-information. The accomplishment of this project will illuminate the relationship between targeted genes, EGFR-TKI resistance and the prognosis of NSCLC and provide a novel target against EGFR-TKI resistance and important insights into mechanisms of drug resistance in NSCLC.