title: Thioltransferase overexpression increases resistance of MCF-7 cells to adriamycin.
abstract: Thioltransferase, a small redox protein with thiol-disulfide oxidoreductase and dehydroascorbate reductase activities, has been reported to be expressed at higher levels in Adriamycin-resistant MCF-7 human breast tumor cells (MCF-7 ADR(R)) when compared with Adriamycin sensitive MCF-7 WT (MCF-7 WT) cells. The present study examined the effects of stably transfecting MCF-7 WT cells with the cDNA for human thioltransferase and the effects of subsequent Adriamycin cytotoxicity in the MCF-7 WT transfected cells. All transfected cell lines overexpressing thioltransferase activity were more resistant to Adriamycin than untransfected MCF-7 WT cells, supporting the hypothesis that increases in thioltransferase expression are related to Adriamycin resistance. This resistance was independent of the ability of thioltransferase to catalyze reduction of dehydroascorbic acid to ascorbic acid, as the addition of an ascorbate generating derivative, L-ascorbic acid-2-phosphate, to the media did not additionally increase Adriamycin resistance.
authors.affiliation: Department of Biochemistry, Michigan State University, East Lansing 48824, USA.
authors.forename: E B
authors.initials: EB
authors.lastname: Meyer
authors.forename: W W
authors.initials: WW
authors.lastname: Wells
mesh_terms: D001943:Breast Neoplasms; D002470:Cell Survival / Q000187:drug effects; D018076:DNA, Complementary; D004317:Doxorubicin / Q000633:toxicity*; D019008:Drug Resistance, Neoplasm; D005260:Female; D054477:Glutaredoxins; D006801:Humans; D010088:Oxidoreductases / Q000235:genetics* / Q000378:metabolism*; D010920:Placenta / Q000201:enzymology; D011247:Pregnancy; D011490:Protein Disulfide Reductase (Glutathione); D011994:Recombinant Proteins / Q000378:metabolism; D014162:Transfection; D014407:Tumor Cells, Cultured
chemical_list: D018076:DNA, Complementary; D054477:Glutaredoxins; D011994:Recombinant Proteins; D004317:Doxorubicin; D010088:Oxidoreductases; D011490:Protein Disulfide Reductase (Glutathione)