Date of Award
Honors Thesis (Open Access)
Colby College. Chemistry Dept.
Kevin P. Rice
Julie T. Millard
Sulfonylhydrazines are a class of DNA alkylating drugs which also produce carbamoylating activity in situ. The carbamoylating species is of significance because it has shown to inhibit important thiol-containing enzymes such as glutathione reductase (GR) and thioredoxin reductase (TrxR). TrxR catalyzes dithiol-disulfide exchange reactions on thioredoxin (Trx), which in turn catalyzes other reductive processes such as deoxyribonucleotide biosynthesis. In this study, we demonstrate that TrxR activity is strongly inhibited by the anticancer prodrug Cloretazine both in purified form and in leukemia cell lysates. This inhibition is specific to the carbamoylating activity of methylisocyanate (MiC). In contrast, another important oxidoreductase, glutathione reductase (GR), was inhibited in purified form, but showed little susceptibility to Cloretazine in the cellular context. These results suggest the mode of inhibition against TrxR and GR differs inside of cells. Due to the overexpression of TrxR in cancer cells and its role in DNA metabolism, inhibiting TrxR may be important to the activity of the anticancer agent Cloretazine.
Cloretazine, Antineoplastic agents, Thioredoxin
Recommended CitationSchleicher, Tyler R., "Inhibition of cellular thioredoxin reductase by the anticancer prodrug cloretazine" (2008). Honors Theses. Paper 220.
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