title: Effects of selenium supplementation on expression of glutathione peroxidase isoforms in cultured human lung adenocarcinoma cell lines.
abstract: Selenium is an essential nutrient, a component of several anti-oxidant enzymes, and a possible factor in cancer risk, including lung cancer. We determined the subtoxic range of selenium concentration (as sodium selenite) required to increase and maintain the expression of anti-oxidant selenoproteins gluthathione peroxidases GPX1 and GPX4 at a constant level in cultures of human lung adenocarcinoma cell lines (H460, H1703 and H1944) and in HPL1D, a non-transformed lung epithelial cell line. Selenium dose-dependently increased GPX1 protein expression 1.8-fold in HPL1D cells and approximately 40-fold in H460 and H1944 cancer cells, with maximum effects at 20-40 nM. GPX4 protein was also increased, but more so in HPL1D (five-fold) than in H460 or H1944 cells (two- to three-fold). GPX1 mRNA showed similar patterns but differences of lesser magnitude. GPX1 protein and activity level was not consistently detectable in H1703 cells, with or without Se supplementation; its mRNA was present but very low. GPX4 protein level was also low in H1703 cells, but was markedly increased by selenium supplementation (48-fold). These results confirm a role for selenium in risk of lung cancer and the independent regulation of GPX1 and GPX4. Characterization of individual tumors with regard to GPX1 and GPX4 levels and regulation might be useful for interpretation of clinical studies on effects of selenium in lung cancer risk.
authors.affiliation: Laboratory of Comparative Carcinogenesis, National Cancer Institute at Frederick, Building 538, Ft. Detrick, Frederick, MD 21702, USA. mromanowska@ncifcrf.gov
authors.forename: Malgorzata
authors.initials: M
authors.lastname: Romanowska
authors.forename: Keith D
authors.initials: KD
authors.lastname: Kikawa
authors.forename: Janet R
authors.initials: JR
authors.lastname: Fields
authors.forename: Anna
authors.initials: A
authors.lastname: Maciag
authors.forename: S Lynn
authors.initials: SL
authors.lastname: North
authors.forename: Yih-Horng
authors.initials: YH
authors.lastname: Shiao
authors.forename: Kazimierz S
authors.initials: KS
authors.lastname: Kasprzak
authors.forename: Lucy M
authors.initials: LM
authors.lastname: Anderson
mesh_terms: D000230:Adenocarcinoma / Q000201:enzymology*; D045744:Cell Line, Tumor; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects*; D005979:Glutathione Peroxidase / Q000235:genetics*; D006801:Humans; D008175:Lung Neoplasms / Q000201:enzymology*; D000080662:Phospholipid Hydroperoxide Glutathione Peroxidase; D012333:RNA, Messenger / Q000235:genetics; D012643:Selenium / Q000494:pharmacology*; D000094765:Glutathione Peroxidase GPX1
chemical_list: D012333:RNA, Messenger; D000080662:Phospholipid Hydroperoxide Glutathione Peroxidase; D005979:Glutathione Peroxidase; D012643:Selenium; D000094765:Glutathione Peroxidase GPX1; C000722067:GPX1 protein, human