Abstract 2896: Effects of hypoxia on normal prostate fibroblast and prostate cancer associated fibroblast metabolism and matrix degradation
Authors: Pacheco-Torres Jesus , Shah Tariq , Brennen W. Nathaniel , Wildes Flonne , Bhujwalla Zaver M. 
Published: July 2021

Synopsis: Fibroblasts are versatile cells that produce several ECM proteins such as collagen 1 as well as degradative enzymes such as matrix metalloproteinases. In cancer, fibroblasts play a significant role in tumor progression and dissemination, immunosuppression and metabolic support of cancer cells. We have identified increased cancer associated fibroblasts (CAFs) in more metastatic prostate cancers. Here we investigated the influence of hypoxia in modifying fibroblast metabolism and matrix degradation. We characterized metabolic changes triggered by hypoxia in normal prostate fibroblasts and prostate CAFs using magnetic resonance spectroscopy (MRS). We assessed changes in prostate fibroblast invasion and ECM degradation with our MR-compatible cell perfusion system (MR-CPS).

Methods: Experiments were performed using human prostate fibroblasts (WPMY-1, ATCC, Manassas, VA) and human prostate cancer associated fibroblasts (PCAFs, Asterand Bioscience, Detroit, MI). WPMY-1 were derived from stromal cells from the peripheral zone of the histologically normal adult prostate. PCAFs were obtained from an adenocarcinoma of the prostate gland. To induce hypoxia, WPMY-1 cells were incubated for 48h under hypoxic conditions (0% O2). For MRS, cell extracts were obtained using a dual-phase extraction method, and HR-MRS performed and analyzed as previously described. MR-CPS experiments were carried out with WPMY-1 cells plated on ECM chamber under well-oxygenated (70% O2) or hypoxic (1% O2) conditions as previously detailed by us.

Results: Under normoxia, compared with WPMY-1, PCAFs displayed significantly higher levels of glutamine, glutamate, arginine, lactate, myo-inositol, creatine (Cr), phosphocreatine (PCr), choline (cho) and lower levels of phosphocholine (PC). The response to low oxygenation was completely different between WPMY-1 and PCAFs. WPMY-1 responded to hypoxia with increased levels of glutamine, glutamate, myo-inositol, arginine, PCr and glycerophosphocholine (GPC). PCAFs, on the other hand, responded to hypoxia with decreased levels of arginine, PC, Cr, glutamine, glutamate and lactate. Finally, hypoxia triggered a significantly faster degradation of the ECM by prostate fibroblasts early in the course of the experiment, but not at later time points.

Discussion: We found that hypoxia significantly altered the metabolism of both normal and cancer associated fibroblasts. The metabolic profile of WPMY-1 under hypoxia became similar to PCAFs under normoxia. ECM degradation by normal fibroblast increased under hypoxic conditions. Some of the metabolic changes can be related to supporting cancer cell metabolism and creating an immunosuppressive tumor microenvironment. These data suggest that hypoxia plays an important role in the metabolic transformation of fibroblasts to a malignant metabolic phenotype.

Supported by NIH R35 CA209960.

Citation Format: Jesus Pacheco-Torres, Tariq Shah, W. Nathaniel Brennen, Flonne Wildes, Zaver M. Bhujwalla. Effects of hypoxia on normal prostate fibroblast and prostate cancer associated fibroblast metabolism and matrix degradation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2896.