E3泛素连接酶RNF6介导PTEN降解在非小细胞肺癌EGFR-TKI耐药中的作用及机制研究

获得性耐药是非小细胞肺癌EGFR-TKI治疗失败的主要原因，但机制尚未完全明确。本团队已发表研究与既往报道均表明E3泛素连接酶RNF6在肿瘤进展中起重要作用。预实验发现：在非小细胞肺癌EGFR-TKI耐药细胞中RNF6表达增加，降低RNF6的表达可增强EGFR-TKI敏感性，并抑制细胞上皮间质转化（EMT）。进一步探索发现，沉默RNF6可抑制EMT相关信号通路PI3K/AKT的激活，且PTEN是RNF6的潜在底物。据此我们提出假说：RNF6介导PTEN泛素化降解激活PI3K/AKT通路进而诱发EMT，最终导致非小细胞肺癌EGFR-TKI耐药。为验证假设，本项目将利用组织芯片、基因转染、体外泛素化实验和裸鼠荷瘤模型等技术，从分子、细胞、组织、动物水平证实RNF6调控PTEN介导非小细胞肺癌EGFR-TKI耐药的作用并阐明其分子机制。研究结果将为临床防治EGFR-TKI耐药提供新思路。

Acquired drug resistance is the major reason for the failure of EGFR-TKI therapy in non-small cell lung cancer, but the mechanism is not yet fully clear. Our published research and the previous reports demonstrated that E3 ubiquitin ligase RNF6 played an important role in tumor development. The results of pre-experiment indicated that RNF6 expression was increased in EGFR-TKI-resistant non-small-cell lung cancer cells, and RNF6 silence could enhance the sensitivity and inhibit the epithelial-mesenchymal transition(EMT) process of drug-resistant cells. In addition, the proteomic results showed that silencing RNF6 could inhibit the activation of PI3K/AKT, an EMT-related signaling pathway in EGFR-TKI-resistant non-small-cell lung cancer cells. Further research found that PTEN was a potential substrate of RNF6. According to this, we put forward a hypothesis that RNF6 could mediate PTEN ubiquitination degradation to activate PI3K/AKT pathway and further induce EMT, which eventually leads to EGFR-TKI resistance in non-small cell lung cancer. To verify the hypothesis, This study will use techniques such as tissue chip, gene transfection, in vitro ubiquitylation experiment and nude mouse tumor-bearing model to confirm the role of RNF6 in regulating PTEN-mediated EGFR-TKI resistance of non-small cell lung cancer at the molecular, cellular, tissue and animal levels and elucidate its molecular mechanism.The results of this study will provide new ideas for the clinical prevention and treatment of EGFR-TKI resistance.