The effect of breast tumour and normal breast tissue cytosols on oestradiol 17 beta-hydroxysteroid dehydrogenase activity.
We have prepared cytosols of normal breast tissue and breast tumour tissue and examined their effect on 17 beta-oestradiol dehydrogenase (E2DH) activity in cultured normal breast fibroblasts and on the MCF-7 breast cancer cell line. Tumour cytosol increased the activity of E2DH in the reductive (E1----E2) direction in both MCF-7 cells and normal breast fibroblasts. E2DH activity in the oxidative (E2----E1) direction did not change. Increasing the amount of tumour cytosol progressively raised E2DH activity in the E1----E2 direction in MCF-7 cells, whereas equivalent amounts of cytosol from normal tissue had no effect. No change was seen in the oxidative direction. These findings suggest that a factor present in breast tumours may influence E2DH activity and consequently, the hormonal environment and growth of tumours.
Singh
A
A
Department of Chemical Pathology, St. Mary's Hospital Medical School, London, U.K.
Reed
M J
MJ
Ghilchik
M W
MW
James
V H
VH
D015067:17-Hydroxysteroid Dehydrogenases / Q000032:analysis*; D001940:Breast / Q000201:enzymology*; D001943:Breast Neoplasms / Q000201:enzymology*; D003600:Cytosol / Q000201:enzymology; D004958:Estradiol / Q000378:metabolism*; D005260:Female; D006801:Humans; D014407:Tumor Cells, Cultured
D004958:Estradiol; D015067:17-Hydroxysteroid Dehydrogenases