title: Estrogen and progesterone up-regulate glucose transporter expression in ZR-75-1 human breast cancer cells.
abstract: Breast cancer incidence increases in women receiving combined estrogen and progesterone therapy. Breast tumors show increased expression of the glucose transporter GLUT1. We determined the effect of these hormones on GLUT1-4 expression and deoxyglucose transport in ZR-75-1 breast cancer cells. Immunoblotting, immunocytochemistry, flow cytometry, and RT-PCR showed that GLUT1 expression is up-regulated by progesterone and, to a greater degree, combined therapy. GLUT2 expression is unaffected by hormonal treatment. GLUT3 protein and RNA is up-regulated by progesterone and combined therapy, and GLUT4 protein expression is up-regulated by all hormonal treatments. Deoxyglucose transport studies revealed the presence of three transport components with characteristics corresponding to GLUT1/4, GLUT2, and GLUT3. 17beta-Estradiol produced a slight increase in transport at the Michaelis constant (Km) corresponding to GLUT3. Progesterone produced a small increase in transport at the Km corresponding to GLUT1/4, and combined 17beta-estradiol and progesterone produced a small increase in transport at the Km corresponding to GLUT3 and a large increase in transport at the Km corresponding to GLUT1/4. This indicates that 17beta-estradiol and progesterone differentially regulate GLUT1-4 expression and that these changes correlate to changes in glucose uptake. We postulate that combined hormone replacement therapy provides a survival advantage to developing ZR-75 breast cancer cells.
authors.affiliation: Laboratorio de Biología Celular y Molecular, Millennium Institute of Fundamental and Applied Biology, Universidad Nacional Andrés Bello, Republica 217, Piso 4, Santiago, Casilla 52164, Chile. rmedina@unab.cl.
authors.forename: Rodolfo A
authors.initials: RA
authors.lastname: Medina
authors.forename: Ana Maria
authors.initials: AM
authors.lastname: Meneses
authors.forename: Juan Carlos
authors.initials: JC
authors.lastname: Vera
authors.forename: Catherine
authors.initials: C
authors.lastname: Guzman
authors.forename: Francisco
authors.initials: F
authors.lastname: Nualart
authors.forename: Allisson
authors.initials: A
authors.lastname: Astuya
authors.forename: María Angeles
authors.initials: MA
authors.lastname: García
authors.forename: Sumie
authors.initials: S
authors.lastname: Kato
authors.forename: Andrés
authors.initials: A
authors.lastname: Carvajal
authors.forename: Mauricio
authors.initials: M
authors.lastname: Pinto
authors.forename: Gareth I
authors.initials: GI
authors.lastname: Owen
mesh_terms: D001943:Breast Neoplasms / Q000378:metabolism*; D003847:Deoxyglucose / Q000493:pharmacokinetics; D004958:Estradiol / Q000494:pharmacology*; D005260:Female; D006801:Humans; D009004:Monosaccharide Transport Proteins / Q000235:genetics / Q000378:metabolism*; D011374:Progesterone / Q000494:pharmacology*; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D014407:Tumor Cells, Cultured; D015854:Up-Regulation
chemical_list: D009004:Monosaccharide Transport Proteins; D020033:Protein Isoforms; D012333:RNA, Messenger; D011374:Progesterone; D004958:Estradiol; D003847:Deoxyglucose