AXL负向调控RIPK3介导的NSCLC细胞程序性坏死在大分割放疗抵抗中的作用及机制研究

Hypofractionated radiotherapy achieved a remarkable efficacy in the treatment of patients with early-stage non-small cell lung cancer (NSCLC), but HFRT resistance was the bottleneck. Applicant has demonstrated that RIPK3-mediated necroptosis in NSCLC affects the efficacy of HFRT, but the expression of RIPK3 was low in NSCLC tissues, the molecular mechanism of negative regulation of RIPK3 mediated-necroptosis of NSCLC cells in HFRT resistance has not been elucidated. Applicant has screened and identified that AXL negatively regulated the expression of RIPK3 by RNA-sequencing technology. Based on our series of preliminary results, applicant proposes that HFRT activates the AXL-ERK/AKT signaling pathway, which in turn phosphorylates the transcription factor Ets1, then phosphorylated Ets1 binds to the RIPK3 promoter region, down-regulates RIPK3 expression, inhibits necroptosis of NSCLC cells, and induces HFRT resistance. Thus, intervention in this pathway could overcome HFRT resistance and improve efficacy. We will analyze the hypothesis at four levels: molecules, cells, animal models, and early-stage NSCLC patients. The completion of this subject will provide new ideas and new targets for clarifying the theory of radiobiology of HFRT resistance, and optimizing HFRT individualized treatment strategy. It has important theoretical significance and application prospect.

大分割放射治疗（HFRT）早期NSCLC取得显著疗效，但HFRT抵抗是瓶颈。申请者已证明RIPK3介导的NSCLC程序性坏死影响HFRT疗效，但RIPK3在NSCLC中低表达，而负向调控RIPK3的表达水平及其介导的肿瘤细胞程序性坏死在HFRT抵抗中的作用及分子机制尚未阐明。申请者采用RNA-sequencing筛选并鉴定出AXL负向调控NSCLC细胞的RIPK3表达水平；进而在预实验基础上提出假说：HFRT激活AXL-ERK/AKT信号通路，促使转录因子Ets1磷酸化并核转位，磷酸化的Ets1与RIPK3启动子区结合，抑制RIPK3的表达水平及肿瘤细胞程序性坏死，诱导HFRT抵抗；干预此通路可逆转HFRT抵抗提高疗效。本研究将从分子、细胞、动物模型及患者四个水平深入解析该假说，为阐明HFRT抵抗放射生物学理论、优化HFRT个体化治疗方案提供新思路、新靶点，具有重要的理论意义和应用前景。

大分割放射治疗(HFRT)早期NSCLC取得显著疗效，但HFRT抵抗是瓶颈。申请者已证明RIPK3介导的NSCLC程序性坏死影响HFRT疗效，但RIPK3在NSCLC中低表达，而负向调控RIPK3的表达水平及其介导的肿瘤细胞程序性坏死在HFRT抵抗中的作用及分子机制尚未阐明。申请者采用RNA-sequencing筛选并鉴定出AXL负向调控NSCLC细胞的RIPK3表达水平;进而验证HFRT激活AXL-ERK/AKT信号通路，促使转录因子Ets1磷酸化并核转位，磷酸化的Ets1与RIPK3启动子区结合，抑制RIPK3的表达水平及肿瘤细胞程序性坏死，诱导HFRT抵抗;且HFRT激活AXL也通过负向调控RIPK3的磷酸化，从而抑制细胞程序性坏死的发生，诱导HFRT抵抗。干预AXL及信号通路可逆转HFRT抵抗并提高疗效。本研究将从分子、细胞、动物模型及患者四个水平深入解析该假说，为阐明HFRT抵抗放射生物学理论、优化HFRT个体化治疗方案提供新思路、新靶点，具有重要的理论意义和应用前景。