Journal Article

The 15kDa Selenoprotein and Thioredoxin Reductase 1 Promote Colon Cancer by Different Pathways

Carlson, Bradley A., Asaki, Esther, Reinhold, William C., Naranjo-Suarez, Salvador, Davis, Cindy D., He, Yiwen, Seifried, Harold E., Xu, Xue-Ming, Yoo, Min-Hyuk, Tsuji, Petra A., Hatfield, Dolph L., Gladyshev, Vadim N.

2015

Overview

Selenoproteins mediate much of the cancer-preventive properties of the essential nutrient selenium, but some of these proteins have been shown to also have cancer-promoting effects. We examined the contributions of the 15kDa selenoprotein (Sep15) and thioredoxin reductase 1 (TR1) to cancer development. Targeted down-regulation of either gene inhibited anchorage-dependent and anchorage-independent growth and formation of experimental metastases of mouse colon carcinoma CT26 cells. Surprisingly, combined deficiency of Sep15 and TR1 reversed the anti-cancer effects observed with down-regulation of each single gene. We found that inflammation-related genes regulated by Stat-1, especially interferon-γ-regulated guanylate-binding proteins, were highly elevated in Sep15-deficient, but not in TR1-deficient cells. Interestingly, components of the Wnt/β-catenin signaling pathway were up-regulated in cells lacking both TR1 and Sep15. These results suggest that Sep15 and TR1 participate in interfering regulatory pathways in colon cancer cells. Considering the variable expression levels of Sep15 and TR1 found within the human population, our results provide insights into new roles of selenoproteins in cancer.

• Publisher: Public Library of Science,Public Library of Science (PLoS)
• Subject: Animals / Anticancer properties / Apoptosis / Biological response modifiers / Cell growth / Cell Line, Tumor / Cell Proliferation / Chemical bonds / Colon cancer / Colonic Neoplasms - enzymology / Colonic Neoplasms - metabolism / Colonic Neoplasms - pathology / Colorectal cancer / Gene expression / Gene Expression Profiling / Genetics / Human populations / Information technology / Interferon / Laboratories / Metastases / Mice / Mice, Inbred BALB C / Molecular biology / Neoplasm Metastasis / Protein binding / Proteins / Proteomics / Selenium / Selenoproteins / Selenoproteins - genetics / Selenoproteins - metabolism / Signal transduction / Signaling / Stat1 protein / Thioredoxin / Thioredoxin Reductase 1 - genetics / Thioredoxin Reductase 1 - metabolism / Thioredoxins / Tumorigenesis / Wnt protein / Yang, Cindy / β-Catenin