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Title: Thioredoxin reductase 1 ablation sensitizes colon cancer cells to methylseleninate-mediated cytotoxicity

Abstract

The relationship between selenium and cancer is complex because individuals with low serum selenium levels benefit from selenium supplementation, but those with high serum selenium levels are at increased risk for other diseases. This suggests that the use of selenocompounds might be limited to particular circumstances, such as adjuvant therapy. A contributor to this dichotomy may be the activity of certain selenium containing enzymes like the cytosolic thioredoxin reductase (TR1). We evaluated the cellular response to select selenocompounds that have anticancer activity when TR1 was attenuated by siRNA in RKO colon cancer cells. Methylseleninic acid (MSA), which is a substrate for TR1, enhanced cytotoxicity to colon cancer cells when TR1 was attenuated. MSA induced stress in the endoplasmic reticulum, as measured by GRP78 protein levels. However, this pathway did not appear to account for the change in cytotoxicity when TR1 was attenuated. Instead, knockdown of the cytosolic TR plus incubation with MSA increased autophagy, as measured by LC3B cleavage, and apoptosis, as measured by Annexin V and mitochondrial dysfunction. Therefore, the use of selenocompounds with anticancer activity, like MSA, might be utilized most effectively with agents that targets TR1 in chemotherapeutic applications.

Authors:
;  [1]
  1. Department of Pharmacology and Toxicology, University of Utah, L.S. Skaggs Pharmacy, Rm. 201, 30 S 2000 East, Salt Lake City, UT 84112 (United States)
Publication Date:
OSTI Identifier:
21344818
Resource Type:
Journal Article
Journal Name:
Toxicology and Applied Pharmacology
Additional Journal Information:
Journal Volume: 241; Journal Issue: 3; Other Information: DOI: 10.1016/j.taap.2009.09.010; PII: S0041-008X(09)00402-5; Copyright (c) 2009 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Journal ID: ISSN 0041-008X
Country of Publication:
United States
Language:
English
Subject:
60 APPLIED LIFE SCIENCES; ABLATION; APOPTOSIS; ENDOPLASMIC RETICULUM; ENZYMES; LARGE INTESTINE; MITOCHONDRIA; NEOPLASMS; SELENIUM; THERAPY; TOXICITY; BODY; CELL CONSTITUENTS; DIGESTIVE SYSTEM; DISEASES; ELEMENTS; GASTROINTESTINAL TRACT; INTESTINES; MEDICINE; ORGANIC COMPOUNDS; ORGANS; PROTEINS; SEMIMETALS

Citation Formats

Honeggar, Matthew, Beck, Robert, and Moos, Philip J., E-mail: philip.moos@utah.ed. Thioredoxin reductase 1 ablation sensitizes colon cancer cells to methylseleninate-mediated cytotoxicity. United States: N. p., 2009. Web. doi:10.1016/j.taap.2009.09.010.
Honeggar, Matthew, Beck, Robert, & Moos, Philip J., E-mail: philip.moos@utah.ed. Thioredoxin reductase 1 ablation sensitizes colon cancer cells to methylseleninate-mediated cytotoxicity. United States. https://doi.org/10.1016/j.taap.2009.09.010
Honeggar, Matthew, Beck, Robert, and Moos, Philip J., E-mail: philip.moos@utah.ed. 2009. "Thioredoxin reductase 1 ablation sensitizes colon cancer cells to methylseleninate-mediated cytotoxicity". United States. https://doi.org/10.1016/j.taap.2009.09.010.
@article{osti_21344818,
title = {Thioredoxin reductase 1 ablation sensitizes colon cancer cells to methylseleninate-mediated cytotoxicity},
author = {Honeggar, Matthew and Beck, Robert and Moos, Philip J., E-mail: philip.moos@utah.ed},
abstractNote = {The relationship between selenium and cancer is complex because individuals with low serum selenium levels benefit from selenium supplementation, but those with high serum selenium levels are at increased risk for other diseases. This suggests that the use of selenocompounds might be limited to particular circumstances, such as adjuvant therapy. A contributor to this dichotomy may be the activity of certain selenium containing enzymes like the cytosolic thioredoxin reductase (TR1). We evaluated the cellular response to select selenocompounds that have anticancer activity when TR1 was attenuated by siRNA in RKO colon cancer cells. Methylseleninic acid (MSA), which is a substrate for TR1, enhanced cytotoxicity to colon cancer cells when TR1 was attenuated. MSA induced stress in the endoplasmic reticulum, as measured by GRP78 protein levels. However, this pathway did not appear to account for the change in cytotoxicity when TR1 was attenuated. Instead, knockdown of the cytosolic TR plus incubation with MSA increased autophagy, as measured by LC3B cleavage, and apoptosis, as measured by Annexin V and mitochondrial dysfunction. Therefore, the use of selenocompounds with anticancer activity, like MSA, might be utilized most effectively with agents that targets TR1 in chemotherapeutic applications.},
doi = {10.1016/j.taap.2009.09.010},
url = {https://www.osti.gov/biblio/21344818}, journal = {Toxicology and Applied Pharmacology},
issn = {0041-008X},
number = 3,
volume = 241,
place = {United States},
year = {Tue Dec 15 00:00:00 EST 2009},
month = {Tue Dec 15 00:00:00 EST 2009}
}