Project description:In this study, we sought to investigate the metabolic role of MALAT1, one of the most abundant cancer-associated long non-coding RNA, in prostate cancer. MALAT1 targeting by gapmerization reduced expression of some tricarboxylic acid cycle enzymes including the malic enzyme 3 and the pyruvate dehydrogenase kinases 1 and 3 as well as the choline kinase A. In consequence, prostate cancer metabolism switched toward a glycolytic phenotype characterized by increased lactate production paralleled by growth arrest, and cell death. Conversely, the function of mitochondrial succinate dehydrogenase and expression of oxphos enzymes was markedly reduced, suggesting for a decreased tricarboxylic acid cycle and mitochondrial respiration activity. Interestingly, a similar effect was observed in several prostate cancer-derived organotypic slice cultures, in which metabolism became more glycolytic and apoptotic. Based on these observations, we elaborated a predictive algorithm, in which those metabolic enzymes sensitive to MALAT1 targeting proven successfully to predict tumor recurrence in a subset of patients. In summary, MALAT1 targeting by gapmerization activates a metabolic switch in the prostate cancer cell and tumor tissue unraveling a role for crucial metabolic enzymes in tumor progression and outcome.
Project description:The lncRNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) promotes growth and progression in prostate cancer (PCa); however, little is known about its possible impact in PCa metabolism. The aim of this work has been the assessment of the metabolic reprogramming associated with MALAT1 silencing in human PCa cells and in an ex vivo model of organotypic slice cultures (OSCs). Cultured cells and OSCs derived from primary tumors were transfected with MALAT1 specific gapmers. Cell growth and survival, gene profiling, and evaluation of targeted metabolites and metabolic enzymes were assessed. Computational analysis was made considering expression changes occurring in metabolic markers following MALAT1 targeting in cultured OSCs. MALAT1 silencing reduced expression of some metabolic enzymes, including malic enzyme 3, pyruvate dehydrogenase kinases 1 and 3, and choline kinase A. Consequently, PCa metabolism switched toward a glycolytic phenotype characterized by increased lactate production paralleled by growth arrest and cell death. Conversely, the function of mitochondrial succinate dehydrogenase and the expression of oxidative phosphorylation enzymes were markedly reduced. A similar effect was observed in OSCs. Based on this, a predictive algorithm was developed aimed to predict tumor recurrence in a subset of patients. MALAT1 targeting by gapmer delivery restored normal metabolic energy pathway in PCa cells and OSCs.
Project description:Icariin Ameliorates Exercise-Induced Fatigue by Promoting TFEB-Dependent Mitochondrial Clearance and Metabolic Re-programming, which reveals a novel molecular mechanism underlying icariin’s anti-fatigue efficacy and highlights its potential as a natural agent for enhancing exercise capacity.
Project description:Lcariin Ameliorates Exercise-Induced Fatigue by Promoting TFEB-Dependent Mitochondrial Clearance and Metabolic Re-programming, which reveals a novel molecular mechanism underlying icariin’s anti-fatigue efficacy and highlights its potential as a natural agent for enhancing exercise capacity.
Project description:Transcriptome analysis of control and MALAT1 lncRNA-depleted RNA samples from human diploid lung fibroblasts [WI38] The long noncoding MALAT1 RNA is upregulated in cancer tissues and its elevated expression is associated with hyper-proliferation, but the underlying mechanism is poorly understood. We demonstrate that MALAT1 levels are regulated during normal cell cycle progression. Genome-wide transcriptome analyses in normal human diploid fibroblasts reveal that MALAT1 modulates the expression of cell cycle genes, and is required for G1/S and mitotic progression. Depletion of MALAT1 leads to activation of p53 and its target genes. The cell cycle defects observed in MALAT1-depleted cells are sensitive to p53 levels, indicating that p53 is a major downstream mediator of MALAT1 activity. Furthermore, MALAT1-depleted cells display reduced expression of B-MYB (Mybl2), an oncogenic transcription factor involved in G2/M progression, due to altered binding of splicing factors on B-MYB pre-mRNA and aberrant alternative splicing. In human cells, MALAT1 promotes cellular proliferation by modulating the expression and/or pre-mRNA processing of cell cycle-regulated transcription factors. These findings provide mechanistic insights on the role of MALAT1 in regulating cellular proliferation. We analyzed RNA from control and MALAT1 depleted WI38 cells using the Affymetrix Human Exon 1.0 ST platform. Array data was analyzed by Partek Genomic Suite software.
Project description:Previously, lncRNA Malat1 knockout mice were generated by insertional inactivation. By crossing this line to MMTV-PyMT mammary tumor mouse model, we produced PyMT;Malat1 wild-type (WT) and PyMT;Malat1 knockout (KO). Furthermore, we generated Malat1 transgenic mice by targeting ROSA26 locus and bred them to PyMT;Malat1 knockout mice to produce Malat1-rescued PyMT;Malat1 knockout;Malat1 transgenic animals (TG). Using mammary tumors from the three groups of animals, we performed RNA-Seq analysis to identify differentially up-regulated genes in KO tumors to find novel target genes of YAP-TEAD pathway.
Project description:The long noncoding MALAT1 RNA is upregulated in cancer tissues and its elevated expression is associated with hyper-proliferation, but the underlying mechanism is poorly understood. We demonstrate that MALAT1 levels are regulated during normal cell cycle progression. Genome-wide transcriptome analyses in normal human diploid fibroblasts reveal that MALAT1 modulates the expression of cell cycle genes, and is required for G1/S and mitotic progression. Depletion of MALAT1 leads to activation of p53 and its target genes. The cell cycle defects observed in MALAT1-depleted cells are sensitive to p53 levels, indicating that p53 is a major downstream mediator of MALAT1 activity. Furthermore, MALAT1-depleted cells display reduced expression of B-MYB (Mybl2), an oncogenic transcription factor involved in G2/M progression, due to altered binding of splicing factors on B-MYB pre-mRNA and aberrant alternative splicing. In human cells, MALAT1 promotes cellular proliferation by modulating the expression and/or premRNA processing of cell cycle-regulated transcription factors. These findings provide mechanistic insights on the role of MALAT1 in regulating cellular proliferation. Keywords: MALAT1; MALAT-1, NEAT2, ncRNA; E2F, alternative splicing; pre-mRNA splicing factors WI38 cells (normal human diploid fibroblasts) were transfected with a control oligo (CTR) or antisense oligos to MALAT1 and RNA was isolated after 48 hr. Two antisense oligos were use for MALAT1 (AS-1 and AS-2). Arrays were done for 3 sets of samples in triplicate (control, AS-1 and AS-2).