Biology subjects

Linge, A.

Publications and source records attributed to Linge, A..

4 recordsLinked to original sources

bioRxiv2025

Glutamine transporters regulate prostate cancer radiosensitivity through NUPR1-mediated stress response

BackgroundMetabolic 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. MethodsThe 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 genesets, and a geneset 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. {gamma}H2A.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. ResultsDepletion of these transporters led to reduced cell viability, altered ROS levels, and enhanced radiosensitivity in PCa cell lines. Functional assays revealed that targeting these transporters decreases CSC properties, impairs cell cycle progression, and deregulates mitochondrial energy metabolism. Our findings indicate that the Gln transporters mediate the adaptation of tumor cells to nutrient stress, while NUPR1 promotes cellular survival under metabolic and genotoxic stress. Targeting SLC1A5, SLC7A5, SLC38A1, and NUPR1 radiosensitizes PCa by disrupting metabolic adaptations and stress responses. Besides, CB-839, a glutaminase (GLS) inhibitor, combined with RT, demonstrated a synergistic effect with radiotherapy in vivo, significantly delaying tumor growth. We found that GLS gene expression levels are significantly associated with clinical outcomes in PCa patients treated with RT. ConclusionsOur work underscores the role of Gln transporters and the NUPR1-mediated stress response induced by Gln deficiency in PCa cell survival, stemness, mitochondrial functions and radioresistance. Our findings provide a potential therapeutic in vivo strategy to enhance the efficacy of RT and improve treatment outcomes for PCa patients.

cancer biology↗

bioRxiv2024

Blood-based detection of MMP11 as a marker of prostate cancer progression regulated by the ALDH1A1-TGF-β1 signaling mechanism

BackgroundProstate cancer (PCa) is the second most common type of tumor diagnosed in men and the fifth leading cause of cancer-related death in male patients. The response of metastatic disease to standard treatment is heterogeneous. As for now, there is no curative treatment option available for metastatic PCa, and the clinical tests capable of predicting metastatic dissemination and metastatic response to the therapies are lacking. Our recent study identifies aldehyde dehydrogenases ALDH1A1 and ALDH1A3 as critical regulators of PCa metastases. Still, the exact mechanisms mediating the role of these proteins in PCa metastatic dissemination remain not fully understood, and plasma-based biomarkers of these metastatic mechanisms are also not available. MethodsGenetic silencing, gene overexpression, or treatment with different doses of the retinoic acid (RA) isomers, which are the products of ALDH catalytic activity, were used to modulate the interplay between retinoic acid receptors (RARs) and androgen receptor (AR). RNA sequencing (RNAseq), reporter assays, and chromatin immunoprecipitation (ChIP) analysis were employed to validate the role of RARs and AR in the regulation of the transforming growth factor-beta 1 (TGFB1) expression. Gene expression levels of ALDH1A1, ALDH1A3, and the matrix metalloproteinase 11 (MMP11) and their correlation with pathological parameters and clinical outcomes were analyzed by mining several publicly available patient datasets as well as our multi-center transcriptomic dataset from patients with high-risk and locally advanced PCa. The levels of MMP11 protein were analyzed by enzyme-linked immunosorbent assay (ELISA) in independent cohorts of plasma samples from patients with localized or metastatic PCa and healthy donors, while plasma proteome profiles were obtained for selected subsets of PCa patients. ResultsWe could show that ALDH1A1 and ALDH1A3 genes differently regulate TGFB1 expression in a RAR-and AR-dependent manner. We further observed that the TGF-{beta}1 pathway contributes to the regulation of the MMPs, including MMP11. We have confirmed the relevance of MMP11 as a promising clinical marker for PCa using several independent gene expression datasets. Further, we have validated plasma MMP11 levels as a prognostic biomarker in patients with metastatic PCa. Finally, we proposed a hypothetical ALDH1A1/MMP11-related plasma proteome-based prognostic signature. ConclusionsTGFB1/MMP11 signaling contributes to the ALDH1A1-driven PCa metastases. MMP11 is a promising blood-based biomarker of PCa progression.

cancer biology↗

bioRxiv2021

GLS-driven glutamine catabolism contributes to prostate cancer radiosensitivity by regulating the redox state, stemness and ATG5-mediated autophagy

Radiotherapy is one of the curative treatment options for localized prostate cancer (PCa). The curative potential of radiotherapy is mediated by irradiation-induced oxidative stress and DNA damage in tumor cells. However, PCa radiocurability can be impeded by tumor resistance mechanisms and normal tissue toxicity. Metabolic reprogramming is one of the major hallmarks of tumor progression and therapy resistance. Here, we found that radioresistant PCa cells and prostate cancer stem cells (CSCs) have a high glutamine demand. Glutaminase (GLS)-driven catabolism of glutamine serves not only for energy production but also for the maintenance of the redox state. Consequently, glutamine depletion or inhibition of critical regulators of glutamine utilization, such as glutaminase (GLS) and the transcription factor MYC results in PCa radiosensitization. On the contrary, we found that a combination of glutamine metabolism inhibitors with irradiation does not cause toxic effects on nonmalignant prostate cells. Glutamine catabolism contributes to the maintenance of CSCs through regulation of the alpha-ketoglutarate (-KG)-dependent chromatin-modifying dioxygenase. The lack of glutamine results in the inhibition of CSCs with a high aldehyde dehydrogenase (ALDH) activity, decreases the frequency of the CSC populations in vivo and reduces tumor formation in xenograft mouse models. Moreover, this study shows that activation of the ATG5-mediated autophagy in response to a lack of glutamine is a tumor survival strategy to withstand radiation-mediated cell damage. In combination with autophagy inhibition, the blockade of glutamine metabolism might be a promising strategy for PCa radiosensitization. High blood levels of glutamine in PCa patients significantly correlate with a shorter prostate-specific antigen (PSA) doubling time. Furthermore, high expression of critical regulators of glutamine metabolism, GLS1 and MYC, is significantly associated with a decreased progression-free survival in PCa patients treated with radiotherapy. Our findings demonstrate that GLS-driven glutaminolysis is a prognostic biomarker and therapeutic target for PCa radiosensitization.

cancer biology↗

bioRxiv2018

Subjugation of TGFβ Signaling by Human Papilloma Virus in Head and Neck Squamous Cell Carcinoma Shifts DNA Repair from Homologous Recombination to Alternative End-Joining

Purpose: Following cytotoxic therapy, 70% of patients with human papillomavirus (HPV) positive oropharyngeal head and neck squamous cell carcinoma (HNSCC) are alive at 5 years compared to 30% of those with similar HPV-negative cancer, which is thought to be due to dysregulation of DNA repair. Loss of transforming growth factor {beta} (TGF{beta}) signaling is a poorly studied consequence of HPV that could contribute to this phenotype.\n\nExperimental Design: Human HNSCC cell lines (n=9), patient-derived xenografts (n=9), tissue microarray (n=194), TCGA expression data and primary tumor specimens (n=10) were used to define the relationship between TGF{beta} competency, response to DNA damage, and type of DNA repair.\n\nResults: Analysis of HNSCC specimens in situ and in vitro showed that HPV associates with loss of TGF{beta} signaling that increases the response to radiation or cisplatin. TGF{beta} suppressed miR-182 that inhibited both BRCA1, necessary for homologous recombination repair, and FOXO3, which is required for ATM kinase activity. TGF{beta} signaling blockade by either HPV or inhibitors released this control, compromised HRR and increased response to PARP inhibition. Antagonizing miR-182 rescued the homologous recombination deficit in HPV+ cells. Loss of TGF{beta} signaling unexpectedly increased error-prone, alternative end-joining repair.\n\nConclusions: HPV-positive HNSCC cells are unresponsive to TGF{beta}. Abrogated TGF{beta} signaling compromises homologous recombination and shifts reliance on alt-EJ repair that provides a mechanistic basis for sensitivity to PARP inhibitors. The effect of HPV in HNSCC provides critical validation of TGF{beta}s role in DNA repair proficiency and further raises the translational potential of TGF{beta} inhibitors in cancer therapy.

cancer biology↗