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.
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)
Project description:Obesity is associated with systemic inflammation that impairs mitochondrial function. This disruption curtails oxidative metabolism, limiting adipocyte lipid metabolism and thermogenesis, a metabolically beneficial program that dissipates chemical energy as heat. Here, we show that PGC1α, a key governor of mitochondrial biogenesis, is negatively regulated at the level of its mRNA translation by the RNA-binding protein RBM43. RBM43 is induced by inflammatory cytokines and suppresses mitochondrial biogenesis in a PGC1α-dependent manner. In mice, adipocyte-selective Rbm43 disruption elevates PGC1α translation and oxidative metabolism. In obesity, Rbm43 loss improves glucose tolerance, reduces adipose inflammation, and suppresses activation of the innate immune sensor cGAS-STING in adipocytes. We further identify a role for PGC1α in safeguarding against cytoplasmic accumulation of mitochondrial DNA, a cGAS ligand. The action of RBM43 defines a translational regulatory axis by which inflammatory signals dictate cellular energy metabolism and contribute to metabolic disease pathogenesis.
Project description:Peroxisome proliferator-activated receptor (PPAR) γ coactivator 1α (PGC1α) is a coactivator of various nuclear receptors and other transcription factors that shows increased expression in skeletal muscle during exercise. In skeletal muscle, PGC1α is considered to be involved in contractile protein function, mitochondrial function, metabolic regulation, intracellular signaling, and transcriptional responses. Several isoforms of PGC1α mRNA have recently been identified. PGC1α-a is a full-length isoform of PGC1α that was the first to be isolated. PGC1α-b is another isoform of PGC1α, which is considered to be similar in function to PGC1α-a, differing by only 16 amino acids at the amino terminus. We have previously generated independent lines of transgenic mice that overexpress PGC1α-a or PGC1α-b in skeletal muscle. The microarray data shows that energy metabolism-related pathways such as the TCA cycle, branched-chain amino acid metabolism, purine nucleotide pathway, and malate–aspartate shuttle are activated in PGC1α transgenic mice compared with wild-type mice. For microarray analysis, RNA was isolated from the gastrocnemius skeletal muscle of wild-type control mice (12 weeks of age) as well as transgenic mice [PGC1α-a (E) (Miura et al., J. Biol. Chem. 278:31385-90, 2003), 12 weeks of age; PGC1α-b (02-1) (Miura et al., Endocrinology 149:4527-33, 2008), 14 weeks of age; and PGC1α-b (03-2) (Miura et al., Endocrinology 2008), 14 weeks of age]. Samples from wild-type and transgenic mice (N = 5 for each group) were pooled before use.
Project description:Lon protease 1 (LONP1) is an ATP-dependent protease located in the mitochondrial matrix and plays a crucial role in regulating mitochondrial proteostasis, metabolism and cellular stress responses. Here we show that overexpression of LONP1 is closely related to adverse clinicopathological features and poor prognosis in prostate cancer (PCa) patients. Mechanistically, the findings reveal that LONP1 is implicated in modulating the metabolic switch from oxidative phosphorylation (OXPHOS) to aerobic glycolysis, thereby promoting tumor proliferation, invasion and metastasis both in vitro and in vivo. Meanwhile, we prove that LONP1 as a protease directly targets mitochondrial pyruvate carrier 1 (MPC1), a key metabolic protein in the process of glycolysis, and enhances its degradation, which in turn suppresses tricarboxylic acid (TCA) cycle and ultimately promotes the progression of PCa. Furthermore, using PCa in cancer-prone mice homozygous for a prostate-targeted conditional Pten knockout and Lonp1 knockin, we integrate transcriptomic and proteomic analyses of prostate tumors, upon which reveals that Lonp1 overexpression results in a significant downregulation of NADH: ubiquinone oxidoreductase activity, consequently impeding the electron transfer process and mitochondrial ATP synthesis, associated with metastasis of PCa. Collectively, our results highlight that metabolic reprogramming induced by LONP1 in PCa is closely coupled with disease progression, suggesting that targeting the LONP1-mediated cascade in the mitochondrial may provide therapeutic potential for PCa disease.
Project description:Protein 4.1B is a 4.1/ezrin/radixin/moesin (FERM) domain-containing protein whose expression is frequently lost in a variety of human tumors, including meningiomas, non-small-cell lung cancers and breast carcinomas. However, its potential tumor suppressive function under in vivo conditions remains to be validated. In a screen for genes involved with prostate cancer metastasis, we found that 4.1B expression is reduced in highly metastatic tumors. Downregulation of 4.1B increased the metastatic propensity of poorly metastatic cells in an orthotopic model of prostate cancer. Furthermore, 4.1B-deficient mice displayed increased susceptibility for developing aggressive, spontaneous prostate carcinomas. In both cases, enhanced tumor malignancy was associated with reduced apoptosis. As expression of Protein 4.1B is frequently downregulated in human clinical prostate cancer, as well as in a spectrum of other tumor types, these results suggest a more general role for Protein 4.1B as a negative regulator of cancer progression to metastatic disease. Experiment Overall Design: primary cell line vs metastasis cell line
Project description:Peroxisome proliferator-activated receptor (PPAR) γ coactivator 1α (PGC1α) is a coactivator of various nuclear receptors and other transcription factors that shows increased expression in skeletal muscle during exercise. In skeletal muscle, PGC1α is considered to be involved in contractile protein function, mitochondrial function, metabolic regulation, intracellular signaling, and transcriptional responses. Several isoforms of PGC1α mRNA have recently been identified. PGC1α-a is a full-length isoform of PGC1α that was the first to be isolated. PGC1α-b is another isoform of PGC1α, which is considered to be similar in function to PGC1α-a, differing by only 16 amino acids at the amino terminus. We have previously generated independent lines of transgenic mice that overexpress PGC1α-a or PGC1α-b in skeletal muscle. The microarray data shows that energy metabolism-related pathways such as the TCA cycle, branched-chain amino acid metabolism, purine nucleotide pathway, and malate–aspartate shuttle are activated in PGC1α transgenic mice compared with wild-type mice.
Project description:The increasing incidence of obesity poses great challenges and demands for developing effective therapeutic approaches. We aimed to reveal the anti-obesity effects of tetrahydroberberrubine (THBru), a derivative of berberine (BBR) and elucidate its underlying mechanism. The anti-obesity effects of THBru and BBR were assessed and compared using an obese mouse model induced by high fat diet (HFD). THBru was found to markedly ameliorated obesity, indicated by reduced body weight, decreased Lee’s index, lowered epididymal white adipose tissue (WAT) and brown adipose tissue (BAT) fat mass as well as improved dyslipidemia. At the same dose, THBru produced greater anti-obesity effects than BBR. RNA-sequencing and gene set enrichment analysis indicated THBru activated thermogenesis, which was further confirmed in WAT, BAT, and 3T3-L1 cells. Bioinformatics analysis of RNA-sequencing data revealed the candidate gene Pgc1α, a key regulator involved in thermogenesis. Moreover, THBru was demonstrated to elevate the expression of PGC1α by stabilizing its mRNA in WAT, BAT and 3T3-L1 cells. Furthermore, PGC1α knockdown blocked the pro-thermogenic and anti-obesity action of THBru both in vivo and in vitro. This study indicated THBru exerted anti-obesity effects by activating PGC1α-mediated thermogenesis and outlined its potential preventive and therapeutic implications for obesity and related diseases.
Project description:Dynamic interaction between prostate cancer and the bone microenvironment is a major contributor to metastasis of prostate cancer to bone. In this study we utilized an in-vitro co-culture model of PC3 prostate cancer cells and osteoblasts followed by microarray based gene expression profiling to identify previously unrecognized prostate cancer-bone microenvironment interactions. Factors secreted by PC3 cells resulted in the up-regulation of many genes in osteoblasts associated with bone metabolism and cancer metastasis, including Mmp13, Il-6 and Tgfb2, and down-regulation of Wnt inhibitor Sost. To determine whether altered Sost expression in the bone microenvironment has an effect on prostate cancer metastasis, we co-cultured PC3 cells with Sost knockout (SostKO) osteoblasts and wildtype (WT) osteoblasts and identified several genes differentially regulated between PC3-SostKO osteoblast co-cultures and PC3-WT osteoblast co-cultures. Co-culturing PC3 cells with WT osteoblasts up-regulated cancer-associated long noncoding RNA (lncRNA) MALAT1 in PC3 cells. MALAT1 expression was further enhanced when PC3 cells were co-cultured with SostKO osteoblasts and treatment with recombinant Sost down-regulated MALAT1 expression in these cells. Our results suggest that reduced Sost expression in the tumor microenvironment may promote bone metastasis by up-regulating MALAT1 in prostate cancer.