Thioredoxin is a small redox protein that undergoes NADPH-dependent reduction by the flavoprotein thioredoxin reductase. Thioredoxin provides reducing equivalents to ribonucleotide reductase, the first unique step of DNA synthesis, and through thiol-disulfide exchange regulates the activity of a number of transcription factors. Redox activity is essential for the biological activity of thioredoxin. Our work provides strong evidence that the gene for thioredoxin is a new human oncogene. We have shown that transfection of mouse NIH 3T3 normal embryonic cells with human thioredoxin causes their transformation. Transfection of mouse thymoma cells with thioredoxin inhibits spontaneous and drug induced apoptosis in vitro and in vivo, and causes aggressive tumor growth in vivo. Transfection of human cancer cells with thioredoxin increases their anchorage independent growth and stimulates tumor growth in vivo. In contrast, transfection with a dominant-negative redox-inactive thioredoxin inhibits anchorage-independent growth and completely prevents tumor formation by the cells in vivo. We have shown that half of the human primary lung, colon, and gastric cancers over-express thioredoxin compared to normal tissue. In human primary gastric carcinomas, thioredoxin over- expression is highly correlated with increased cell proliferation and decreased apoptosis. Thus, the hypothesis on which our studies are based is that thioredoxin is a critical regulator of the growth and transformed phenotype of some human cancers and that over-expression of thioredoxin may be a cause of human cancer. We also propose that thioredoxin offers a rational and feasible target for the development of new drugs for the treatment of cancer. There remain important unanswered questions concerning the role thioredoxin plays in human cancer, its mechanism of action, its ability to determine response to therapy and the action of drugs that inhibit thioredoxin. These questions will be addressed by our proposed studies.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
5R01CA048725-10
Application #
6172373
Study Section
Special Emphasis Panel (ZRG2-ET-2 (02))
Program Officer
Forry-Schaudies, Suzanne L
Project Start
1990-08-01
Project End
2001-07-31
Budget Start
2000-08-01
Budget End
2001-07-31
Support Year
10
Fiscal Year
2000
Total Cost
$150,396
Indirect Cost
Name
University of Arizona
Department
Other Health Professions
Type
Schools of Medicine
DUNS #
806345617
City
Tucson
State
AZ
Country
United States
Zip Code
85721
Ihle, Nathan T; Williams, Ryan; Chow, Sherry et al. (2004) Molecular pharmacology and antitumor activity of PX-866, a novel inhibitor of phosphoinositide-3-kinase signaling. Mol Cancer Ther 3:763-72
Meuillet, Emmanuelle J; Mahadevan, Daruka; Vankayalapati, Hariprasad et al. (2003) Specific inhibition of the Akt1 pleckstrin homology domain by D-3-deoxy-phosphatidyl-myo-inositol analogues. Mol Cancer Ther 2:389-99
Husbeck, B; Berggren, M I; Powis, G (2001) DNA microarray reveals increased expression of thioredoxin peroxidase in thioredoxin-1 transfected cells and its functional consequences. Adv Exp Med Biol 500:157-68
Powis, G; Montfort, W R (2001) Properties and biological activities of thioredoxins. Annu Rev Biophys Biomol Struct 30:421-55
Kakolyris, S; Giatromanolaki, A; Koukourakis, M et al. (2001) Thioredoxin expression is associated with lymph node status and prognosis in early operable non-small cell lung cancer. Clin Cancer Res 7:3087-91
Powis, G; Montfort, W R (2001) Properties and biological activities of thioredoxins. Annu Rev Pharmacol Toxicol 41:261-95
Berggren, M M; Powis, G (2001) Alternative splicing is associated with decreased expression of the redox proto-oncogene thioredoxin-1 in human cancers. Arch Biochem Biophys 389:144-9
Berggren, M I; Husbeck, B; Samulitis, B et al. (2001) Thioredoxin peroxidase-1 (peroxiredoxin-1) is increased in thioredoxin-1 transfected cells and results in enhanced protection against apoptosis caused by hydrogen peroxide but not by other agents including dexamethasone, etoposide, and doxorubicin. Arch Biochem Biophys 392:103-9
Baker, A; Santos, B D; Powis, G (2000) Redox control of caspase-3 activity by thioredoxin and other reduced proteins. Biochem Biophys Res Commun 268:78-81
Freemerman, A J; Powis, G (2000) A redox-inactive thioredoxin reduces growth and enhances apoptosis in WEHI7.2 cells. Biochem Biophys Res Commun 274:136-41

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