放射治疗是非小细胞肺癌（NSCLC）患者治疗的重要方法。肿瘤放疗耐受性是限制NSCLC患者放疗有效性的主要因素。我们的研究旨在揭示肿瘤微环境的一个主要成分——癌相关成纤维细胞（CAFs）是否调节了放疗后NSCLC细胞的DNA损伤反应，并澄清涉及的机制。我们发现，CAFs抑制了放疗诱导的NSCLC细胞的DNA损伤，同时促进了其DNA修复，并导致放疗耐受的S期中细胞周期阻滞。CAFs能够上调和稳定c-Myc，通过激活Wnt/β-连环蛋白通路，引起糖酵解关键限速酶HK2激酶的转录活化。糖酵解的减弱明显使CAFs对NSCLC细胞DNA损伤反应的影响发生逆转。通过人类细胞因子/趋化因子高通量筛选，我们发现CAFs分泌的Midkine促进了Wnt/β-连环蛋白通路在NSCLC细胞中激活糖酵解。在体内，CAFs也通过促进糖酵解依赖于β-连环蛋白信号传导方式导致NSCLC细胞的放疗耐受。这些发现可能为改变NSCLC细胞的放疗耐受提供新的策略。版权所有©2023 Elsevier B.V.出版。

Radiotherapy is an essential treatment modality for the management of non-small cell lung cancer (NSCLC) patients. Tumor radioresistance is the major factor limiting the efficacy of radiotherapy in NSCLC patients. Our study aimed to reveal whether cancer-associated fibroblasts (CAFs), one main component of the tumor microenvironment, regulated DNA damage response of NSCLC cells following irradiation and clarify the involved mechanisms. We found CAFs inhibited irradiation-induced DNA damage while promoted DNA repair of NSCLC cells and caused cell cycle arrest in the radioresistant S phase. CAFs have the ability of up-regulating and stabilizing c-Myc, leading to the transcription activation of HK2 kinase, a key rate-limiting enzyme in glycolysis by activating Wnt/β-catenin pathway. Attenuation of glycolysis significantly reversed the effect of CAFs on DNA damage response of NSCLC cells. By high-throughput screening of human cytokines/chemokines array, we found CAFs-secreted midkine led to the promotion of glycolysis by activating Wnt/β-catenin pathway in NSCLC cells. In vivo, CAFs caused the radioresistance of NSCLC cells also by promoting the glycolysis in a β-catenin signaling-dependent manner. These findings may provide novel strategies for reversing the radioresistance of NSCLC cells.Copyright © 2023. Published by Elsevier B.V.