NLRX1缺失介导的琥珀酰化修饰失衡对肝癌免疫检查点抑制剂耐药的促进作用与机制研究

耐药是肝癌免疫检查点抑制剂（PD-1抗体）应用中面临的一大难题。申请人在既往发现NLRX1是一种新型肝癌抑制分子的基础上，进一步NLRX1表达缺失可造成肝癌糖代谢重编程产生“瓦博格效应”，并籍此途径诱导胞内赖氨酸琥珀酰化修饰水平升高，最终驱动肝癌PD-1耐药发生；进一步实验显示P65蛋白L376位点琥珀酰化修饰介导的NF-kB信号活化是NLRX1表达缺失诱导肝癌PD-1耐药的潜在机制。本课题拟在前期基础上运用空间转录组测序、质谱、免疫系统人源化PDX模型等技术平台，从细胞、动物、临床三个层面展开研究，明确NLRX1在调控肝癌糖代谢与赖氨酸琥珀酰化修饰中的作用；阐明NLRX1表达缺失诱导P65发生琥珀酰化修饰驱动肝癌PD1耐药的分子机制；初步探索敲入NLRX1策略对改善PD-1耐药的价值。预期成果可为PD-1耐药提供全新的“糖代谢-转录后修饰”调控模式，并为临床改善PD-1疗效提供全新思维。

Resistance emerges as a major problem in the application of immune checkpoint inhibitors (i.e. PD-1 antibodies) for hepatocellular carcinoma (HCC). Based on previous study demonstrating that NLRX1 was a novel tumor suppressor in HCC, we further found that the NLRX1 expression deficiency could result in "Warburg effect" via inducing glycometabolism reprogramming in HCC cells. Consequently, the level of intracellular lysine succinylation could be significantly increased, which ultimately drives the development of PD-1 resistance in HCC. In addition, activation of NF-kB signaling pathway mediated by succinylation at L376 residue of p65 protein was unveiled as a potential mechanism for NLRX1-deficiency induced PD-1 resistance. In present study, on the basis of previously demonstrated results of preliminary experiments, we aimed to use a variety of advanced technologies including 10x genomics spatial transcriptome sequencing, MS, and Humanized PDX models to carry out systematic research from the distinct levels including cell, animal and clinical in order to determine the role of NLRX1 in regulating glucose metabolism as well as Lysine succinylation modification in HCC, and to elucidate the molecular mechanism of NLRX1 induced succinylation modification of p65 to drive PD1 resistance of HCC. Moreover, we also intended to explore the value of NLRX1 knock-in strategy in reversing PD-1 resistance phenotypes. The expected results might establish a bright new regulation interplay model of "glycometabolism-posttranscriptional modification" for PD-1 resistance in HCC, and provide a novel insight for enhancing treatment efficacy of PD-1.