Stimulatory effect of 1,25-dihydroxyvitamin D3 on the glucose-6-phosphate dehydrogenase activity in the MCF-7 human breast cancer cell line.
Human breast cancer cell lines have been shown to possess high affinity receptors for 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) and their growth is inhibited by this steroid. The present study examines the effect of 1,25(OH)2D3 on the activity of glucose-6-phosphate dehydrogenase (G6PD) in cells of a human breast cancer cell line MCF-7. G6PD, an enzyme which controls the hexose monophosphate shunt, is elevated and sensitive to 17 beta-estradiol in breast tumors. G6PD activity was stimulated by 1,25(OH)2D3 in a dose-dependent manner at very low concentrations of steroid (10(-10)-10(-12) M). 1,25(OH)2D3 increased maximum velocity without modifying the affinity constant of the enzyme for glucose-6-phosphate.
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CNRS UA583, Hôpital Necker, Paris, France.
Garabedian
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Monet
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D001943:Breast Neoplasms / Q000201:enzymology*; D002117:Calcitriol / Q000494:pharmacology*; D004789:Enzyme Activation / Q000187:drug effects; D004958:Estradiol / Q000494:pharmacology; D005260:Female; D005954:Glucosephosphate Dehydrogenase / Q000378:metabolism*; D006801:Humans; D007700:Kinetics; D013268:Stimulation, Chemical; D014407:Tumor Cells, Cultured
D004958:Estradiol; D005954:Glucosephosphate Dehydrogenase; D002117:Calcitriol