Increased levels of cytosolic thioredoxin reductase activity and mRNA in rat liver nodules.
BACKGROUND/AIMS: Thioredoxin reductase, a redox active enzyme, is induced in several tumors. This study focuses on the presence of and subcellular localisation of thioredoxin reductase in a tumor model where neoplastic lesions are selected by their resistance to the toxic effects of the promotor. METHODS: Liver nodules produced by intermittent feeding of 2-acetylaminofluorene to male Wistar rats were analyzed for thioredoxin reductase (TrxR) activity and mRNA. RESULTS: This activity was increased 3.5-fold in the cytosol but decreased 60% in the mitochondrial fraction compared to the liver of age-matched untreated animals. Only traces of activity were observed in the microsomal, plasma membrane and nuclear fractions from normal liver or nodules. The level of TrxR mRNA was 3-fold higher in nodules than in normal rat liver. Furthermore, the total level of SH groups in homogenates was 2-fold higher in the case of the nodules. CONCLUSIONS: These findings indicate that the thioredoxin system makes an important contribution to the resistant phenotype of the neoplastic liver cell, which conveys a growth advantage of significance for tumor progression.[1]References
- Increased levels of cytosolic thioredoxin reductase activity and mRNA in rat liver nodules. Björkhem, L., Teclebrhan, H., Kesen, E., Olsson, J.M., Eriksson, L.C., Björnstedt, M. J. Hepatol. (2001) [Pubmed]
Annotations and hyperlinks in this abstract are from individual authors of WikiGenes or automatically generated by the WikiGenes Data Mining Engine. The abstract is from MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.About WikiGenesOpen Access LicencePrivacy PolicyTerms of Useapsburg
