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: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: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:By integration of transcriptome, CHIP-seq, ATAC-seq, proteomic and metabolite screening followed by carbon tracing (U-13C-Glucose, U-13C-Glutamine and U-13C-Palmitic acid) and extracellular flux analysis we provided evidence that genetic (shRNA and CRISPR/Cas9) and pharmacological (Alisertib) AURKA inhibition elicited substantial metabolic reprogramming supported in part by inhibition of MYC targets and concomitant activation of PPARA signaling. While glycolysis was suppressed by AURKA inhibition, we noted a compensatory increase in oxygen consumption rate fueled by enhanced fatty acid oxidation (FAO). Whereas interference with AURKA elicited a suppression of c-Myc, we detected an upregulation of PGC1α, a master regulator of oxidative metabolism, upon AURKA inhibition. Chromatin immunoprecipitation experiments confirmed binding of c-Myc to the promoter region of PGC1α, which is abrogated by AURKA inhibition and in turn unleashed PGC1α expression. To interfere with this oxidative metabolic reprogramming, we combined AURKA inhibitors with inhibitors of FAO (etomoxir) and electron transport chain (gamitrinib) and found substantial synergistic growth inhibition in patient derived xenograft in vitro and extension of overall survival without induction of toxicity in normal tissue.
Project description:By integration of transcriptome, CHIP-seq, ATAC-seq, proteomic and metabolite screening followed by carbon tracing (U-13C-Glucose, U-13C-Glutamine and U-13C-Palmitic acid) and extracellular flux analysis we provided evidence that genetic (shRNA and CRISPR/Cas9) and pharmacological (Alisertib) AURKA inhibition elicited substantial metabolic reprogramming supported in part by inhibition of MYC targets and concomitant activation of PPARA signaling. While glycolysis was suppressed by AURKA inhibition, we noted a compensatory increase in oxygen consumption rate fueled by enhanced fatty acid oxidation (FAO). Whereas interference with AURKA elicited a suppression of c-Myc, we detected an upregulation of PGC1α, a master regulator of oxidative metabolism, upon AURKA inhibition. Chromatin immunoprecipitation experiments confirmed binding of c-Myc to the promoter region of PGC1α, which is abrogated by AURKA inhibition and in turn unleashed PGC1α expression. To interfere with this oxidative metabolic reprogramming, we combined AURKA inhibitors with inhibitors of FAO (etomoxir) and electron transport chain (gamitrinib) and found substantial synergistic growth inhibition in patient derived xenograft in vitro and extension of overall survival without induction of toxicity in normal tissue.
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.
Project description:Purpose: Despite that androgen-deprivation therapy results in long-lasting responses, the disease inevitably progresses to metastatic castration-resistant prostate cancer. In this study, we identified miR-33b-3p as a suppressor of metastasis in prostate cancer. miR-33b-3p was significantly reduced in prostate cancer tissues, and the low expression of miR-33b-3p was correlated with poor overall survival of prostate cancer patients. Overexpression of miR-33b-3p inhibited both migration and invasion of highly metastatic prostate cancer cells whereas antagonizing miR-33b-3p promoted those processes in lowly metastatic cells. The in vivo results demonstrate that miR-33b-3p suppresses metastasis of tail vein inoculated prostate cancer cells to lung, liver, and lymph node in mice. DOCK4 was validated as the direct target of miR-33b-3p. miR-33b-3p decreased the expression of DOCK4 and restoration of DOCK4 could rescue miR-33b-3p inhibition on cell migration and invasion. Moreover, downregulation of miR-33b-3p was induced by bortezomib, the clinically used proteasome inhibitor, and overexpression of miR-33b-3p rescued the insufficient inhibition of bortezomib on migration and invasion in prostate cancer cells. Collectively, our findings demonstrate that miR-33b-3p suppresses metastasis by targeting DOCK4 in prostate cancer. Our results suggest that enhancing miR-33b-3p expression may provide a promising therapeutic strategy for overcoming that proteasome inhibitor’s poor efficacy against metastatic prostate cancer.