Pereira 2009 Biochem J
|Pereira da Silva AP, El-Bacha T, Kyaw N, dos Santos RS, Da Silva WS, Almeida FC, Da Poian AT, Galina A (2009) Inhibition of energy-producing pathways of HepG2 cells by 3-bromopyruvate. Biochem J 417:717-26.|
Abstract: 3-BrPA (3-bromopyruvate) is an alkylating agent with antitumoral activity on hepatocellular carcinoma. This compound inhibits cellular ATP production owing to its action on glycolysis and oxidative phosphorylation; however, the specific metabolic steps and mechanisms of 3-BrPA action in human hepatocellular carcinomas, particularly its effects on mitochondrial energetics, are poorly understood. In the present study it was found that incubation of HepG2 cells with a low concentration of 3-BrPA for a short period (150 μMfor 30 min) significantly affected both glycolysis and mitochondrial respiratory functions. The activity of mitochondrial hexokinase was not inhibited by 150 μM 3-BrPA, but this concentration caused more than 70% inhibition of GAPDH (glyceraldehyde-3-phosphate dehydrogenase) and 3-phosphoglycerate kinase activities. Additionally, 3-BrPA treatment significantly impaired lactate production by HepG2 cells, even when glucose was withdrawn from the incubation medium. Oxygen consumption of HepG2 cells supported by either pyruvate/malate or succinate was inhibited when cells were preincubated with 3-BrPA in glucose-free medium. On the other hand, when cells were pre-incubated in glucose-supplemented medium, oxygen consumption was affected only when succinate was used as the oxidizable substrate. An increase in oligomycinindependent respiration was observed in HepG2 cells treated with 3-BrPA only when incubated in glucose-supplemented medium, indicating that 3-BrPA induces mitochondrial proton leakage as well as blocking the electron transport system. The activity of succinate dehydrogenase was inhibited by 70% by 3-BrPA treatment. These results suggest that the combined action of 3- BrPA on succinate dehydrogenase and on glycolysis, inhibiting steps downstream of the phosphorylation of glucose, play an important role in HepG2 cell death.
• Keywords: 3-bromopyruvate, Glycolysis, Hepatocellular carcinoma, HepG2 cell, Mitochondrion, Oxygen consumption, Tumour cell.
Labels: MiParea: Respiration Pathology: Cancer
Organism: Human Tissue;cell: Liver Preparation: Intact cells, Permeabilized cells
Coupling state: LEAK, ROUTINE, OXPHOS, ET Pathway: S, ROX HRR: Oxygraph-2k