title: Selenium and GPx-1 overexpression protect mammalian cells against UV-induced DNA damage.
abstract: Supplementation of the culture media of human MCF-7 breast carcinoma cells or mouse fibroblasts with low levels of selenium (30 nM) provided as sodium selenite was shown to protect these cells from ultraviolet (UV)-induced chromosome damage, as quantified by micronucleus assay. Selenium supplementation was also effective in reducing UV-induced gene mutations as measured in the lacI shuttle vector model. Protection was dependent on functional BRCA1 activity, a protein implicated in breast cancer risk and DNA damage repair. In addition, overexpression of GPx-1, a selenoprotein with antioxidant activity, also attenuated UV induced micronuclei formation in the absence of selenium supplementation. Combining selenium supplementation with GPx-1 overexpression further reduced UV-induced micronucleus frequency. These data provide evidence that the benefits of selenium supplementation might be either through the prevention or repair of DNA damage, and they implicate at least one selenoprotein (GPx-1) in the process.
authors.affiliation: Department of Human Nutrition, University of Illinois at Chicago, Chicago, IL 60612, USA.
authors.forename: Manjeshwar S
authors.initials: MS
authors.lastname: Baliga
authors.forename: Hengbing
authors.initials: H
authors.lastname: Wang
authors.forename: Pin
authors.initials: P
authors.lastname: Zhuo
authors.forename: Jeffrey L
authors.initials: JL
authors.lastname: Schwartz
authors.forename: Alan M
authors.initials: AM
authors.lastname: Diamond
mesh_terms: D001943:Breast Neoplasms / Q000209:etiology / Q000235:genetics; D045744:Cell Line, Tumor; D002470:Cell Survival; D004249:DNA Damage; D004260:DNA Repair; D019587:Dietary Supplements; D015971:Gene Expression Regulation, Enzymologic; D005979:Glutathione Peroxidase / Q000378:metabolism*; D006801:Humans; D015162:Micronucleus Tests; D016296:Mutagenesis; D012306:Risk; D012643:Selenium / Q000378:metabolism* / Q000494:pharmacology; D018038:Sodium Selenite / Q000494:pharmacology; D014466:Ultraviolet Rays
chemical_list: D005979:Glutathione Peroxidase; D012643:Selenium; D018038:Sodium Selenite