title: Overexpression of mitochondrial thioredoxin reductase and peroxiredoxin III in hepatocellular carcinomas.
abstract: Thioredoxin reductase 2 (TrxR2), thioredoxin II (Trx II) and peroxiredoxin III (Prx III) are specifically localized in mitochondria and believed to play important roles in the regulation of cellular redox status by serving as a primary line of defense against H2O2 produced during respiration. Substantial evidence indicates that the alteration of cellular redox status is a critical factor involved in cell growth and death and results in tumorigenesis. We therefore investigated the expression of TrxR2 and Prx III in 58 paraffin-embedded hepatocellular carcinoma tissues by immunohistochemistry. The labeling indices of TrxR2 and Prx III were significantly higher in tumor tissues than in the corresponding adjacent normal tissues. In 39 (67.2%) out of 58 samples, the levels of TrxR2 expression were higher in tumor tissues than in corresponding adjacent normal tissues, while 11 samples (19.0%) showed lower expression in tumor tissues. Prx III expression was increased in tumor tissues of 23 samples (39.7%) compared to adjacent normal tissues and were decreased in 18 samples (31.0%). These results suggest that alterations in cellular redox status by enhanced expression of TrxR2 and/or Prx III might be associated with the formation and development of hepatocellular carcinomas.
authors.affiliation: Department of Pathology, College of Medicine, Yeungnam University, Daegu, 705-717, Korea.
authors.forename: Joon Hyuk
authors.initials: JH
authors.lastname: Choi
authors.forename: Tae Nyeun
authors.initials: TN
authors.lastname: Kim
authors.forename: Seongyong
authors.initials: S
authors.lastname: Kim
authors.forename: Suk-Hwan
authors.initials: SH
authors.lastname: Baek
authors.forename: Jung Hye
authors.initials: JH
authors.lastname: Kim
authors.forename: Seung Rock
authors.initials: SR
authors.lastname: Lee
authors.forename: Jae-Ryong
authors.initials: JR
authors.lastname: Kim
mesh_terms: D000328:Adult; D000368:Aged; D006528:Carcinoma, Hepatocellular / Q000201:enzymology / Q000378:metabolism* / Q000473:pathology; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007527:Isoenzymes / Q000096:biosynthesis; D008113:Liver Neoplasms / Q000201:enzymology / Q000378:metabolism* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D008928:Mitochondria / Q000201:enzymology / Q000378:metabolism*; D010544:Peroxidases / Q000096:biosynthesis*; D061105:Peroxiredoxin III; D054464:Peroxiredoxins; D013880:Thioredoxin-Disulfide Reductase / Q000096:biosynthesis*
chemical_list: D007527:Isoenzymes; D010544:Peroxidases; C516115:PRDX3 protein, human; D061105:Peroxiredoxin III; D054464:Peroxiredoxins; C500519:TXNRD3 protein, human; D013880:Thioredoxin-Disulfide Reductase