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Modulation of glutathione peroxidase expression by selenium: effect on human MCF-7 breast cancer cell transfectants expressing a cellular glutathione peroxidase cDNA and doxorubicin-resistant MCF-7 cells.
Nucleic Acids Res 1990; 18(6):1531-9NA

Abstract

We have studied the effect of selenium on the expression of a cellular glutathione peroxidase, GSHPx-1, in transfected MCF-7 cells and in doxorubicin-resistant (Adrr) MCF-7 cells. A GSHPx-1 cDNA with a Rous Sarcoma virus promoter was transfected into a human mammary carcinoma cell line, MCF-7, which has very low endogenous cytosolic glutathione (GSH) peroxidase activity and no detectable message. The transfectant with the highest GSH peroxidase activity among the isolates, MCF-7H6, was characterized. Adrr MCF-7 cells, a subline of MCF-7 cells, also has elevated GSH peroxidase activity. GSH peroxidase expressed by MCF-7H6 and Adrr MCF-7 cells is similar to the endogenous GSHPx-1 based on molecular weight, immunoreactivity, and metabolic labeling with 75Se. MCF-7H6 and Adrr MCF-7 cells grown in Se-deficient media had 2.6 +/- 2.4 (mean +/- S.D.) and 4.2 +/- 3.6 units/mg protein of GSH peroxidase specific activity, respectively. Se supplementation increased GSH peroxidase activity in a concentration- and time-dependent fashion. Enzymatic activity reached a level of 164 +/- 62 in MCF-7H6 cells and 114 +/- 27 in Adrr MCF-7 cells within 5 days of growth in media supplemented with 30 nM Se. Northern analysis revealed that Se-deficient MCF-7H6 cells expressed 2.1 +/- 0.4-fold less GSHPx-1 mRNA than their Se-sufficient counterparts. Similarly, Se-deficient Adrr MCF-7 cells expressed 3.3 +/- 1.8-fold less GSHPx-1 mRNA than their Se-supplemented counterparts after the quantity of mRNA was normalized with beta-actin. These studies suggest that modulation of GSH peroxidase activity by Se in both MCF-7H6 transfectants expressing pRSV-GSHPx-1 and Adrr MCF-7 cells expressing endogenous GSHPx-1 occurs largely at the translational level, and to a lesser degree at the level of mRNA, possibly by stabilizing GSHPx-1 mRNA since the transfected cDNA in MCF-7H6 cells has only 5 nucleotides 5' to the AUG initiation codon.

Authors+Show Affiliations

Department of Medical Oncology and Therapeutics Research, City of Hope National Medical Center, Duarte, CA 91010.No affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, P.H.S.

Language

eng

PubMed ID

2158080

Citation

Chu, F F., et al. "Modulation of Glutathione Peroxidase Expression By Selenium: Effect On Human MCF-7 Breast Cancer Cell Transfectants Expressing a Cellular Glutathione Peroxidase cDNA and Doxorubicin-resistant MCF-7 Cells." Nucleic Acids Research, vol. 18, no. 6, 1990, pp. 1531-9.
Chu FF, Esworthy RS, Akman S, et al. Modulation of glutathione peroxidase expression by selenium: effect on human MCF-7 breast cancer cell transfectants expressing a cellular glutathione peroxidase cDNA and doxorubicin-resistant MCF-7 cells. Nucleic Acids Res. 1990;18(6):1531-9.
Chu, F. F., Esworthy, R. S., Akman, S., & Doroshow, J. H. (1990). Modulation of glutathione peroxidase expression by selenium: effect on human MCF-7 breast cancer cell transfectants expressing a cellular glutathione peroxidase cDNA and doxorubicin-resistant MCF-7 cells. Nucleic Acids Research, 18(6), pp. 1531-9.
Chu FF, et al. Modulation of Glutathione Peroxidase Expression By Selenium: Effect On Human MCF-7 Breast Cancer Cell Transfectants Expressing a Cellular Glutathione Peroxidase cDNA and Doxorubicin-resistant MCF-7 Cells. Nucleic Acids Res. 1990 Mar 25;18(6):1531-9. PubMed PMID: 2158080.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Modulation of glutathione peroxidase expression by selenium: effect on human MCF-7 breast cancer cell transfectants expressing a cellular glutathione peroxidase cDNA and doxorubicin-resistant MCF-7 cells. AU - Chu,F F, AU - Esworthy,R S, AU - Akman,S, AU - Doroshow,J H, PY - 1990/3/25/pubmed PY - 1990/3/25/medline PY - 1990/3/25/entrez SP - 1531 EP - 9 JF - Nucleic acids research JO - Nucleic Acids Res. VL - 18 IS - 6 N2 - We have studied the effect of selenium on the expression of a cellular glutathione peroxidase, GSHPx-1, in transfected MCF-7 cells and in doxorubicin-resistant (Adrr) MCF-7 cells. A GSHPx-1 cDNA with a Rous Sarcoma virus promoter was transfected into a human mammary carcinoma cell line, MCF-7, which has very low endogenous cytosolic glutathione (GSH) peroxidase activity and no detectable message. The transfectant with the highest GSH peroxidase activity among the isolates, MCF-7H6, was characterized. Adrr MCF-7 cells, a subline of MCF-7 cells, also has elevated GSH peroxidase activity. GSH peroxidase expressed by MCF-7H6 and Adrr MCF-7 cells is similar to the endogenous GSHPx-1 based on molecular weight, immunoreactivity, and metabolic labeling with 75Se. MCF-7H6 and Adrr MCF-7 cells grown in Se-deficient media had 2.6 +/- 2.4 (mean +/- S.D.) and 4.2 +/- 3.6 units/mg protein of GSH peroxidase specific activity, respectively. Se supplementation increased GSH peroxidase activity in a concentration- and time-dependent fashion. Enzymatic activity reached a level of 164 +/- 62 in MCF-7H6 cells and 114 +/- 27 in Adrr MCF-7 cells within 5 days of growth in media supplemented with 30 nM Se. Northern analysis revealed that Se-deficient MCF-7H6 cells expressed 2.1 +/- 0.4-fold less GSHPx-1 mRNA than their Se-sufficient counterparts. Similarly, Se-deficient Adrr MCF-7 cells expressed 3.3 +/- 1.8-fold less GSHPx-1 mRNA than their Se-supplemented counterparts after the quantity of mRNA was normalized with beta-actin. These studies suggest that modulation of GSH peroxidase activity by Se in both MCF-7H6 transfectants expressing pRSV-GSHPx-1 and Adrr MCF-7 cells expressing endogenous GSHPx-1 occurs largely at the translational level, and to a lesser degree at the level of mRNA, possibly by stabilizing GSHPx-1 mRNA since the transfected cDNA in MCF-7H6 cells has only 5 nucleotides 5' to the AUG initiation codon. SN - 0305-1048 UR - https://www.unboundmedicine.com/medline/citation/2158080/Modulation_of_glutathione_peroxidase_expression_by_selenium:_effect_on_human_MCF_7_breast_cancer_cell_transfectants_expressing_a_cellular_glutathione_peroxidase_cDNA_and_doxorubicin_resistant_MCF_7_cells_ L2 - https://academic.oup.com/nar/article-lookup/doi/10.1093/nar/18.6.1531 DB - PRIME DP - Unbound Medicine ER -