Project description:Recent studies have demonstrated that upon encountering a pathogenic stimulus, robust metabolic rewiring of immune cells occurs. A switch away from oxidative phosphorylation to glycolysis, even in the presence of sufficient amounts of oxygen (akin the Warburg effect), is typically observed in activated innate and adaptive immune cells and is thought to accommodate adequate inflammatory responses. However, whether the Warburg effect is a general phenomenon applicable in human monocytes exposed to different pathogenic stimuli is unknown. Our results using human monocytes from healthy donors demonstrate that the Warburg effect only holds true for TLR4 activated cells. Although activation of other TLRs leads to an increase in glycolysis, no reduction or even an enhancement in oxidative phosphorylation is observed. Moreover, specific metabolic rewiring occurs in TLR4 vs. TLR2 stimulated cells characterized by altered gene expression profiles of pathways related to metabolism, changes in spare respiratory capacity of the cells and differential regulation of mitochondrial enzyme activity. Similarly, results from ex vivo and in vivo studies demonstrate metabolic rewiring of immune cells that is highly dependent on the type of pathogenic stimulus. Although the Warburg effect is observed in human monocytes after TLR4 activation, we propose that this typical metabolic response is not applicable to other inflammatory signalling routes including TLR2 in human monocytes. Instead, each pathogenic stimulus and subsequently activated inflammatory signalling cascade induces specific metabolic rewiring of the immune cell to accommodate an appropriate response.
Project description:Cancer metabolism plays an essential role in therapeutic resistance, where significant inter- and intra-tumoral heterogeneity exists. Hypoxia is a prominent driver of metabolic rewiring behaviors and drug responses. Recapitulating the hypoxic landscape in tumor microenvironment thus offers unique insights into heterogeneity in metabolic rewiring and therapeutic responses, to inform better treatment strategies. We developed a micro-metabolic rewiring (μMeRe) device that provides the scalability and resolution needed to characterize the metabolic rewiring behaviors of different cancer cells in the context of hypoxic solid tumors. Our device generates hypoxia through cellular metabolism without external gas controls, enabling the characterization of cell-specific intrinsic ability to drive hypoxia and undergo metabolic rewiring. We assessed the changes in the transcriptomic profile of different cancer cells in the μMeRe device compared to their normoxia counterpart through bulk RNA-seq. Our data confirms heterogeneity and commonality of rewiring behaviors of diverse cancer cell types.
Project description:The current view of cellular transformation and cancer progression supports the notion that cancer cells must reprogram their metabolism in order to survive and progress in different microenvironments. Master co-regulators of metabolism orchestrate the modulation of multiple metabolic pathways through transcriptional programs, and hence constitute a probabilistically parsimonious mechanism for general metabolic rewiring. Here we show that the transcriptional co-activator PGC1α suppresses prostate cancer progression and metastasis. A metabolic co-regulator data mining analysis unveiled that PGC1α is consistently down-regulated in multiple prostate cancer patient datasets and its alteration is associated with reduced disease-free survival and metastasis. Genetically engineered mouse model studies revealed that compound prostate epithelium-specific deletion of Pgc1a and Pten promotes prostate cancer progression and metastasis, whereas, conversely, PGC1α expression in cell lines inhibits the pre-existing metastatic capacity. Through the application of integrative metabolomics and transcriptomics we demonstrate that PGC1α expression in prostate cancer is sufficient to elicit a global metabolic rewiring that opposes cell growth, consisting of sustained oxidative metabolism at the expense of anabolism. This metabolic program is regulated downstream the Oestrogen-related receptor alpha (ERRα), and PGC1α mutants lacking ERRα activation capacity lack metabolic rewiring capacity and metastasissuppressive function. Importantly, an ERRα signature in prostate cancer recapitulates the prognostic features of PGC1A. Our findings uncover an unprecedented causal contribution of PGC1α to the metabolic switch in prostate cancer and to the suppression of metastatic dissemination. Total RNA was isolated from prostate cancer cell line PC3 expressing or not PGC1a (for induction, cells were treated with doxycycline for 2 passages)