Project description:Glycolysis can improve the tolerance of tissue cells to hypoxia, and its intermediates provide raw materials for the synthesis and metabolism of the tumor cells. If it can inhibit the activity of glycolysis-related enzymes and control the energy metabolism of tumor, it can be targeted for the treatment of malignant tumor. The target proteins phosphoglycerate kinase 2 (PGK2), glycerol-3-phosphate dehydrogenase (GPD2) and glucose-6-phosphate isomerase (GPI) were screened by combining transcriptome, proteomics and reverse docking. We detected the binding constant of the active compound using microscale thermophoresis (MST). It was found that esculetin bound well with three potential target proteins. Esculetin significantly inhibited the rate of glycolysis, manifested by differences of cellular lactate production and glucose consumption in HepG2 cells with or without esculetin. It was found that GPD2 bound strongly to GPI, revealing the direct interaction between the two glycolysis-related proteins. Animal tests have further demonstrated that esculetin may have anticancer effects by affecting the activity of PGK2, GPD2 and GPI. The results of this study demonstrated that esculetin can affect the glucose metabolism by binding to glycolytic proteins, thus playing an anti-tumor role, and these proteins which have direct interactions are potential novel targets for tumor treatment by esculetin.
Project description:The target proteins phosphoglycerate kinase 2 (PGK2), glycerol-3-phosphate dehydrogenase (GPD2)GPD2 and glucose-6-phosphate isomerase (GPI) were screened by combining transcriptome, proteomics and reverse docking We detected the binding constant of the active compound using microscale thermophoresis (MST). It was found that esculetin bound well with three potential target proteins.
Project description:The “Warburg effect” describes the use of aerobic glycolysis by cancer cells to fuel their growth. Lactate dehydrogenase-A (LDHA) is key to this process and catalyzes the interconversion of pyruvate and lactate. Here we used a proteomic approach to identify LDHA as a binding partner of the tumor suppressor FLCN. Canonically, LDHA is thought to be a substrate-regulated enzyme, however our data show that FLCN uncompetitively inhibits LDHA activity by restricting movement of its active site loop. This inhibition appears to be critical in normal cells, as we show FLCN binds to and tightly regulates LDHA activity in order to preserve metabolic homeostasis. Pathogenic mutations of FLCN are associated with LDHA hyperactivity and kidney tumor formation, suggesting a mechanism for FLCN tumor suppressive function. We have identified a cell-permeant ten amino acid peptide based on the FLCN sequence that enters these tumors and inhibits LDHA ex vivo. In a broader context, renal cell carcinomas experience the Warburg effect and show FLCN dissociation from LDHA. Cells that experience this metabolic shift depend on the hyperactivity of LDHA, as previous work has shown attenuation or inhibition of LDHA leads to programmed cell death. Treating these cells with the FLCN-derived peptide causes apoptosis, strongly suggesting that the glycolytic shift of cancer cells is the result of FLCN inactivation or disassociation from LDHA. Taken together, FLCN-mediated inhibition of LDHA provides a new paradigm for the regulation of glycolysis.
Project description:The Warburg effect, consisting of increased glucose uptake and glycolysis, provides metabolic energy as well as cellular building blocks for tumor growth. Inhibition of the Warburg effect with 2-deoxyglucose (2DG) has been explored in clinical trials with limited efficacy. Blockage of glycolysis can induce autopahgy resulting in alternative energy generation through oxidative phosphorylation providing a potential bypass of the effects of inhibition of glycolysis. Here in we demonstrate that activation of AMPK, as a consequence of energetic stress, induces mitochondrial energy production potentially bypassing the effects of glycolysis inhibition. We thus combined blockage of glycolysis by 2DG with inhibition of the electron transfer complex I (ETC1) in the mitochondria with the clinically applicable antidiabetic drug metformin. The combination resulted in activation of AMPK and autopahgy that however rendered eventual depletion of ATP and cell death. Furthermore, combined inhibition of glycolysis and mitochondrial respiration inhibited tumor growth and markedly decreased metastatic capacity in vivo. In order to understand the mechanism of these metabolic inhibitors, we performed whole genome transcriptional analysis. Human SK-4 esophageal cancer cell lines were treated with 5 different treatment groups [2 deoxy glucose (4mM), Metformin (5mM), AICAR (2mM), 2 deoxy glucose (4mM) plus Metformin (5mM) and 2 deoxy glucose (4mM) plus AICAR (2mM)] with non treated control groups for 12 hrs. Each groups was quadruplicated. Microarray experiments and data analysis were done at Dept. of Systems Biology, MDACC (Houston, USA)
Project description:Sialylation of Asparagine 612 inhibits Aconitase activity during mouse sperm capacitation; A possible mechanism for the switch from oxidative phosphorylation to glycolysis.
Project description:FAT10 interacts with MAD2 and caused tumor progression. The hypothesis tested in the present study was FAT10 induces tumor progression through its binding to MAD2 and Disruption of this binding restored its global gene expression