Kahya Uğur, Lukiyanchuk Vasyl, Gorodetska Ielizaveta, Weigel Matthias M, Köseer Ayşe Sedef, Alkan Berke, Savic Dragana, Linge Annett, Löck Steffen, Peitzsch Mirko, Skvortsova Ira-Ida, Krause Mechthild, Dubrovska Anna
OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden and Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany.
Institute of Radiooncology - OncoRay, Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Dresden, Germany.
Cell Commun Signal. 2025 Jul 24;23(1):351. doi: 10.1186/s12964-025-02344-3.
Metabolic and stress response adaptations in prostate cancer (PCa) mediate tumor resistance to radiation therapy (RT). Our study investigated the roles of glutamine (Gln) transporters SLC1A5, SLC7A5, and SLC38A1 in regulating NUPR1-mediated stress response, PCa cell survival, metabolic reprogramming, and response to RT.
The radiosensitizing potential of GLS inhibition with CB-839 was analyzed in prostate cancer xenograft models. The level of gene expression was analyzed by RNA sequencing and RT-qPCR in the established cell lines or patient-derived tumor and adjacent non-cancerous tissues. Phosphoproteomic analysis was employed to identify the underlying signaling pathways. The publicly available PCa patient datasets, and a dataset for the patients treated with RT were analyzed by SUMO software. The key parameters of mitochondrial functions were measured by Seahorse analysis. Analysis of the general oxidative stress level and mitochondrial superoxide detection were conducted using flow cytometry. γH2A.X foci analysis was used to assess the DNA double strand break. Relative cell sensitivity to RT was evaluated by radiobiological clonogenic assays. Aldefluor assay and sphere-forming analysis were used to determine cancer stem cell (CSC) phenotype.
A siRNA-mediated knockdown of Gln transporters SLC1A5, SLC7A5, and SLC38A1 resulted in significant radiosensitization of PCa cells. Consistently, the first-in-clinic glutaminase (GLS) inhibitor CB-839, combined with RT, demonstrated a synergistic effect with radiotherapy in vivo, significantly delaying tumor growth. Inhibition of Gln metabolism or knockdown of Gln transporters SLC1A5, SLC7A5, or SLC38A1 induces expression of NUPR1, a stress response transcriptional regulator, but simultaneously uncouples the NUPR1-driven metabolic stress-adaptation program. Similarly to the effect from NUPR1 knockdown, depletion of these Gln transporters led to reduced cell viability, accumulation of mitochondrial ROS, and increased PCa radiosensitivity. This effect is more pronounced in PCa cells with high dependency on OXPHOS for energy production.
Our work underscores the role of Gln transporters and the NUPR1-mediated stress response in PCa cell survival, oxidative stress, mitochondrial functions, and radioresistance. Our findings provide a potential therapeutic in vivo strategy to enhance the efficacy of RT and suggest a potential synergism between the depletion of Gln transporters or NUPR1 and OXPHOS inhibition.
前列腺癌（PCa）中的代谢和应激反应适应性介导了肿瘤对放射治疗（RT）的抗性。我们的研究调查了谷氨酰胺（Gln）转运蛋白SLC1A5、SLC7A5和SLC38A1在调节NUPR1介导的应激反应、PCa细胞存活、代谢重编程以及对RT反应中的作用。
在前列腺癌异种移植模型中分析了用CB - 839抑制谷氨酰胺酶（GLS）的放射增敏潜力。通过RNA测序和RT - qPCR分析了已建立的细胞系或患者来源的肿瘤及相邻非癌组织中的基因表达水平。采用磷酸化蛋白质组学分析来确定潜在的信号通路。使用SUMO软件分析公开可用的PCa患者数据集以及接受RT治疗的患者数据集。通过海马分析测量线粒体功能的关键参数。使用流式细胞术进行一般氧化应激水平分析和线粒体超氧化物检测。γH2A.X焦点分析用于评估DNA双链断裂。通过放射生物学克隆形成试验评估细胞对RT的相对敏感性。醛脱氢酶分析和球形成分析用于确定癌症干细胞（CSC）表型。
siRNA介导的Gln转运蛋白SLC1A5、SLC7A5和SLC38A1敲低导致PCa细胞显著放射增敏。同样，临床首个谷氨酰胺酶（GLS）抑制剂CB - 839与RT联合在体内显示出与放疗的协同作用，显著延迟肿瘤生长。抑制Gln代谢或敲低Gln转运蛋白SLC1A5、SLC7A5或SLC38A1可诱导应激反应转录调节因子NUPR1的表达，但同时使NUPR1驱动的代谢应激适应程序解偶联。与NUPR1敲低的效果类似，这些Gln转运蛋白的缺失导致细胞活力降低、线粒体ROS积累以及PCa放射敏感性增加。这种效应在对氧化磷酸化（OXPHOS）高度依赖以产生能量的PCa细胞中更为明显。
我们工作强调了Gln转运蛋白和NUPR1介导的应激反应在PCa细胞存活、氧化应激、线粒体功能和放射抗性中的作用。我们的发现提供了一种潜在的体内治疗策略以提高RT的疗效，并表明Gln转运蛋白或NUPR1的缺失与OXPHOS抑制之间存在潜在协同作用。
