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Updated: Sep 14, 2025
Measurements of Physiological Stress Responses in C. Elegans
Published on: May 21, 2020
Disruption of glutamine transport uncouples the NUPR1 stress-adaptation program and induces prostate cancer
Uğur Kahya1,2, Vasyl Lukiyanchuk1,2, Ielizaveta Gorodetska1
1OncoRay - 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.
Background:
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.
Methods:
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.
Results:
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.
Conclusions:
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.
Insights
Targeting glutamine transporters enhances prostate cancer (PCa) cell sensitivity to radiation therapy (RT). Inhibiting these transporters or NUPR1 shows promise for improving RT efficacy by disrupting metabolic adaptation.
Area of Science:
- Oncology
- Metabolic pathways
- Radiation biology
Background:
- Prostate cancer (PCa) exhibits metabolic and stress adaptations that confer resistance to radiation therapy (RT).
- Glutamine (Gln) transporters (SLC1A5, SLC7A5, SLC38A1) play critical roles in PCa cell survival and metabolic reprogramming.
- Investigating these transporters' roles in NUPR1-mediated stress response is crucial for understanding and overcoming RT resistance.
Purpose of the Study:
- To investigate the role of Gln transporters (SLC1A5, SLC7A5, SLC38A1) in NUPR1-mediated stress response.
- To evaluate the impact of Gln transporter inhibition on PCa cell survival, metabolic reprogramming, and response to RT.
- To explore therapeutic strategies for enhancing RT efficacy in prostate cancer.
Main Methods:
- Analysis of gene expression (RNA sequencing, RT-qPCR) in PCa cell lines and patient tissues.
- In vivo studies using prostate cancer xenograft models with GLS inhibitor CB-839 and RT.
- Assessment of mitochondrial function, oxidative stress, DNA damage, and cancer stem cell phenotype.
- Bioinformatic analysis of publicly available PCa patient datasets.
Main Results:
- Knockdown of Gln transporters (SLC1A5, SLC7A5, SLC38A1) significantly radiosensitized PCa cells.
- Combined treatment with GLS inhibitor CB-839 and RT synergistically delayed tumor growth in vivo.
- Inhibition of Gln metabolism or transporter knockdown induced NUPR1 but uncoupled its adaptive stress response, increasing radiosensitivity.
- These effects were more pronounced in PCa cells reliant on OXPHOS for energy.
Conclusions:
- Gln transporters and NUPR1 are key regulators of PCa cell survival, oxidative stress, mitochondrial function, and radioresistance.
- Targeting Gln transporters or NUPR1 presents a potential therapeutic strategy to enhance RT efficacy.
- Combined inhibition of Gln transporters/NUPR1 and OXPHOS may offer synergistic benefits in PCa treatment.
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