Project description:Patients with aggressive prostate cancer generally present with poor outcomes. Identifying the factors regulating prostate cancer aggressiveness may open new avenues in therapy. Specifically, information from prostate cancer patient databases revealed that higher phosphoenolpyruvate carboxykinase isoform 2 (PCK2) levels correlate with more aggressive tumors and lower survival rates. Herein, we show that high tumorigenic prostate cancer cell clones express high levels of PCK2. We found that elevated levels of PCK2 are critical for the glucose metabolic remodeling and the maintenance of tumor-initiating cells (TICs) in aggressive prostate cancer. Our data suggest that PCK2 promotes tumorigenicity by lowering acetyl-CoA levels through reducing the mitochondrial tricarboxylic acid (TCA) cycle. Thus, PCK2 is a potential therapeutic target for aggressive prostate cancer. 2 subclones have been isolated from DU145 cells. The epithelial like (EL) clone has a high tumorigenicity ability and enriched tumor initiating cells than mesenchymal like (ML) clone. Genes with differential expression pattern between these two clones were detected by gene micorarray.
Project description:Patients with aggressive prostate cancer generally present with poor outcomes. Identifying the factors regulating prostate cancer aggressiveness may open new avenues in therapy. Specifically, information from prostate cancer patient databases revealed that higher phosphoenolpyruvate carboxykinase isoform 2 (PCK2) levels correlate with more aggressive tumors and lower survival rates. Herein, we show that high tumorigenic prostate cancer cell clones express high levels of PCK2. We found that elevated levels of PCK2 are critical for the glucose metabolic remodeling and the maintenance of tumor-initiating cells (TICs) in aggressive prostate cancer. Our data suggest that PCK2 promotes tumorigenicity by lowering acetyl-CoA levels through reducing the mitochondrial tricarboxylic acid (TCA) cycle. Thus, PCK2 is a potential therapeutic target for aggressive prostate cancer.
Project description:We have previously reported that phosphoenolpyruvate carboxykinase(Pck) overexpression under glycolytic conditions enables Escherichia coli to harbor a high intracellular ATP pool resulting in enhanced recombinant protein synthesis and biohydrogen production. To understand possible reasons of the high ATP haboring cell, we carried out transcriptome and metabolic flux analysis.
Project description:Cancer cells must adapt metabolically to survive and proliferate when nutrients are limiting. Here we used combined transcriptional-metabolomic network analysis to identify metabolic pathways that support glucose-independent tumor cell growth. We found that glucose deprivation stimulated the re-wiring of the tricarboxylic acid (TCA) cycle and co-opting early steps of gluconeogenesis to promote cell proliferation under low glucose. Glucose limitation promoted the production of phosphoenolpyruvate (PEP) from glutamine, which was used to fuel biosynthetic pathways normally sustained by glucose, including serine and purine biosynthesis. Mitochondrial PEP-carboxykinase (PCK2) was required for this glutamine-dependent metabolic reprogramming. PCK2 expression was dependent on the hypoxia-inducible factors (HIFs), and required to maintain tumor cell proliferation under limiting glucose availability. Elevated PCK2 expression is observed in several human tumor types, and enriched in tumor tissue from non-small cell lung cancer (NSCLC) patients. Our results define a novel role for PCK2 in cancer cell metabolic reprogramming that promotes glucose-independent cell growth and metabolic stress resistance in human tumors.
Project description:The project is focused on the highly conserved sRNA scr5329 in Streptomyces coelicolor. A proteomics approach revealed that the sRNA regulates several metabolic enzymes, among them the Phosphoenolpyruvate-Carboxykinase (PEPCK), a key enzyme of the central carbon metabolism. The sRNA scr5239 promotes its degradation on the post-transcriptional level. The expression itself is dependent on the global transcriptional regulator DasR, which is N-acetylglucosamine-responsive thereby creating a feedback regulation. By post-transcriptional regulation of PEPCK and likely more targets, scr5239 adds an additional layer to the DasR regulatory network, providing a tool to control the metabolism in dependency to the carbon source.
Project description:We have identified a methanol- and biotin-starvation-inducible zinc finger protein named ROP [repressor of phosphoenolpyruvate carboxykinase (PEPCK)] in the methylotrophic yeast Pichia pastoris. When P.pastoris strain GS115 (wild-type, WT) is cultured in biotin-deficient, glucose ammonium (Bio-) medium, growth is suppressed due to the inhibition of anaplerotic synthesis of oxaloacetate, catalysed by the biotin-dependent enzyme pyruvate carboxylase (PC). Deletion of ROP results in a strain (∆ROP) that can grow under biotin-deficient conditions due to derepression of a biotin- and PC-independent pathway of anaplerotic synthesis of oxaloacetate. Northern analysis as well as microarray expression profiling of RNA isolated from WT and ∆ROP strains cultured in Bio(-) medium indicate that expression of the phosphoenolpyruvate carboxykinase gene (PEPCK) is induced in ∆ROP during biotin- or PC-deficiency even under glucose-abundant conditions. There is an excellent correlation between PEPCK expression and growth of ∆ROP in Bio(-) medium, suggesting that ROP-mediated regulation of PEPCK may have a crucial role in the biotin- and PC-independent growth of the ∆ROP strain. To our knowledge, ROP is the first example, of a zinc finger transcription factor involved in the catabolite repression of PEPCK in yeast cells cultured under biotin- or PC-deficient and glucose-abundant conditions.
Project description:We have identified a methanol- and biotin-starvation-inducible zinc finger protein named ROP [repressor of phosphoenolpyruvate carboxykinase (PEPCK)] in the methylotrophic yeast Pichia pastoris. When P.pastoris strain GS115 (wild-type, WT) is cultured in biotin-deficient, glucose ammonium (Bio-) medium, growth is suppressed due to the inhibition of anaplerotic synthesis of oxaloacetate, catalysed by the biotin-dependent enzyme pyruvate carboxylase (PC). Deletion of ROP results in a strain (∆ROP) that can grow under biotin-deficient conditions due to derepression of a biotin- and PC-independent pathway of anaplerotic synthesis of oxaloacetate. Northern analysis as well as microarray expression profiling of RNA isolated from WT and ∆ROP strains cultured in Bio(-) medium indicate that expression of the phosphoenolpyruvate carboxykinase gene (PEPCK) is induced in ∆ROP during biotin- or PC-deficiency even under glucose-abundant conditions. There is an excellent correlation between PEPCK expression and growth of ∆ROP in Bio(-) medium, suggesting that ROP-mediated regulation of PEPCK may have a crucial role in the biotin- and PC-independent growth of the ∆ROP strain. To our knowledge, ROP is the first example, of a zinc finger transcription factor involved in the catabolite repression of PEPCK in yeast cells cultured under biotin- or PC-deficient and glucose-abundant conditions. Agilent one-color experiment,Organism: Pichia pastoris ,Custom Pichia pastoris Gene Expression 8x15k array designed by Genotypic Technology Pvt. Ltd. (Agilent -AMADID: 25088 ) , Labeling kit: Agilent Quick-Amp labeling Kit (p/n5190-0442)
Project description:Pyruvate kinase (PK) catalyzes the conversion of phosphoenolpyruvate to pyruvate during glycolysis. The PK isoform PKM2 has additional roles in regulation of gene transcription and protein phosphorylation. PKM2 controls macrophage metabolic remodeling in inflammation, but its role in T cell biology is poorly understood. These results show that TEPP-46, an activator of PKM2, reduces CD4+ T cell activation, proliferation, and cytokine production by inhibiting essential signaling pathways and preventing glycolysis.
Project description:The protein-tyrosine phosphatase SHP-1 (PTPN6) is an important glucose homeostasis modulator. Besides negatively regulating insulin signaling, the specific role of SHP-1 in metabolic control remains poorly understood. We show that SHP-1 acts as a co-activator for transcription of the phosphoenolpyruvate carboxykinase 1 (PCK1) gene, thereby modulating basal gluconeogenesis in hepatocytes. SHP-1 interacts with RNA polymerase II-subunits and signal transducer and activator of transcription 5 (STAT5), and localizes to the nucleus, where a sub-fraction of SHP-1 associates with chromatin. While SHP-1 binds to the PCK1-promoter, its loss affects RNA polymerase II-recruitment to this and other promoters of genes enriched for glucose metabolism-related functions. SHP-1-downregulation, and similarly STAT5 pharmacological inhibition reduce PCK1-transcript levels correlating with blunted gluconeogenesis. Overall, we identified a novel molecular SHP-1-function, that of a regulator of PCK1-transcription and subsequently hepatic gluconeogenesis, through physical interaction with the transcription machinery, mediated by an Akt-independent mechanism, but independent of STAT5 tyrosine-phosphorylation status.