HMGB1介导的自噬调控非小细胞肺癌吉非替尼获得性耐药及分子机制

The acquired resistance is the primary cause of the treatment failure for Gefitinib in non-small cell lung cancer (NSCLC), and some unknown pathogenesis exists. In our previous study, it was found that the acquired resistance of Gefitinib was related to autophagy, with the activation of HMGB1. What's more, when HMGB1 was blocked through small molecule RNA technology, the acquired resistance of Gefitinib was reversed. Therefore, to address the molecular mechanism of NSCLC Gefitinib acquired resistance, the relationship between autophagy and Gefitinib acquired resistance, and the role of HMGB1 in the development of Gefitinib acquired resistance will be examined at primary/passage NSCLC cells and nudumice models. Furthermore, the signal-path of HMGB1 induced Gefitinib acquired resistance will be explored through cell biology and molecular biology methods. Taken together, our study will not only determine the molecular mechanism of Gefitinib acquired resistance, but also provide the novel theory and target that can be potentially used to enhance the therapeutic efficacy of Gefitinib for NSCLC.

获得性耐药是吉非替尼非小细胞肺癌（NSCLC）临床治疗最终失败的主要原因。最新研究证明自噬参与TKI耐药，但亟需进一步阐明机制，加快临床转化。我们前期对NSCLC患者二次活检标本及吉非替尼敏感/耐药细胞株的对比研究中均发现：吉非替尼通过自噬产生获得性耐药，并伴有调控因子HMGB1的激活；通过小分子RNA技术特异性阻断HMGB1，可逆转吉非替尼的耐药。这提示：HMGB1介导的自噬极可能是NSCLC吉非替尼获得性耐药的关键机制。基于此，本课题以HMGB1功能调控为切入点，在分子、细胞、动物模型等多水平下研究HMGB1在自噬诱导吉非替尼获得性耐药形成过程中的关键作用，并进一步以多种分子生物学手段探索HMGB1调控Beclin和Bcl2信号通路参与自噬诱导耐药的分子过程，旨在阐明HMGB1介导的吉非替尼NSCLC获得性耐药的分子机制，为临床提高吉非替尼NSCLC疗效提供新思路和新靶点。

本研究明确了自噬对于吉非替尼非小细胞肺癌获得性耐药的作用，通过细胞存活实验，自噬标记物的检测、自噬抑制剂和小分子RNA干扰自噬关键基因的实验结果显示，自噬是吉非替尼非小细胞肺癌获得性耐药产生的关键原因。进一步实验研究发现，随着吉非替尼耐药性的升高，细胞内HMGB1表达水平上调。采用RNA干扰技术沉默HMGB1的表达，则可以逆转吉非替尼的获得性耐药，通过脂质体转染法过表达HMGB1，则加剧吉非替尼的获得性耐药。深入的机制研究发现HMGB1通过抑制Bcl2磷酸化介导的Beclin1上调，激活自噬的发生，从而导致获得性耐药的产生。通过本课题的研究，可揭示吉非替尼非EGFR靶点突变的获得性耐药产生的新分子机制，丰富抗肿瘤药物获得性耐药的基础理论；同时明确HMGB1对吉非替尼获得性耐药的正向调控作用，为推动HMGB1抑制剂作为对抗吉非替尼获得性耐药的策略提供实验数据，对临床用药具有重要的指导意义。