title: Activities of antioxidant and redox enzymes in human normal hepatic and hepatoma cell lines.
abstract: The cellular defense system (including glutathione, glutathione-related enzymes, antioxidant and redox enzymes) plays a crucial role in cell survival and growth in aerobic organisms. To understand its physiological role in tumor cells, the glutathione content and related enzyme activities in the human normal hepatic cell line, Chang and human hepatoma cell line, HepG2, were systematically measured and compared. Superoxide dismutase, catalase, and glutathione peroxidase activities are 2.8-, 4.3-, and 2.9-fold higher in HepG2 cells than in Chang cells. Total glutathione content is also about 1.4-fold higher in HepG2, which is supported by significant increases in gamma-glutamylcysteine synthetase and glutathione synthetase activities. Two other glutathione-related enzymes, glutathione reductase and gamma-glutamyltranspeptidase, are upregulated in HepG2 cells. However, thioredoxin reductase and glutathione S-transferase activities are significantly lower in HepG2 cells. These results propose that defense-related enzymes are largely modulated in tumor cells, which might be linked to their growth and maintenance.
authors.affiliation: Division of Life Sciences, Kangwon National University, Chunchon, Korea.
authors.forename: Yuk-Young
authors.initials: YY
authors.lastname: Lee
authors.forename: Hong-Gyum
authors.initials: HG
authors.lastname: Kim
authors.forename: Haeng-Im
authors.initials: HI
authors.lastname: Jung
authors.forename: Youn Hee
authors.initials: YH
authors.lastname: Shin
authors.forename: Sung Min
authors.initials: SM
authors.lastname: Hong
authors.forename: Eun-Hee
authors.initials: EH
authors.lastname: Park
authors.forename: Jae-Hoon
authors.initials: JH
authors.lastname: Sa
authors.forename: Chang-Jin
authors.initials: CJ
authors.lastname: Lim
mesh_terms: D000975:Antioxidants / Q000378:metabolism*; D006528:Carcinoma, Hepatocellular / Q000201:enzymology*; D002460:Cell Line; D054477:Glutaredoxins; D005978:Glutathione / Q000378:metabolism; D005982:Glutathione Transferase / Q000378:metabolism; D006801:Humans; D008099:Liver / Q000201:enzymology*; D010084:Oxidation-Reduction; D018384:Oxidative Stress / Q000502:physiology; D010088:Oxidoreductases / Q000378:metabolism; D011490:Protein Disulfide Reductase (Glutathione); D017382:Reactive Oxygen Species / Q000378:metabolism
chemical_list: D000975:Antioxidants; D054477:Glutaredoxins; D017382:Reactive Oxygen Species; D010088:Oxidoreductases; D011490:Protein Disulfide Reductase (Glutathione); D005982:Glutathione Transferase; D005978:Glutathione