High affinity oestradiol receptors and the activity of glucose-6-phosphate dehydrogenase and lactose synthetase in mammary carcinomata of postmenopausal women

Abstract

Summary.-The determination of hormone inducible proteins in endocrine tumours may yield information about the presence of hormone dependent tumour cells. We have estimated the high affinity oestradiol binding capacity in primary mammary carcinomata of 57 postmenopausal patients. Glucose-6-phosphate dehydrogenase and lactose synthetase are known from animal experiments to be hormone inducible. Therefore, in biopsies of sufficient size the activity of glucose-6-phosphate dehydrogenase (47 patients) and lactose synthetase (23 patients) was also studied. It was found that biopsies with high binding capacity also showed high activities of glucose -6-phosphate dehydrogenase and lactose synthetase A protein (galactosyl transferase). No lactose synthetase B protein (a-lactalbumin) has been discovered in the tumours. The present observations may be considered suggestive evidence of a relationship between high oestradiol binding capacity and high activities of the two enzymes on the one hand and hormone dependence of the tumour on the other. However, further clinical studies are required before final conclusions in this respect can be drawn.

Effect of hormone manipulation on oxidation, reduction and sulphurylation of dehydroepiandrosterone and oestrone in DMBA-induced rat mammary tumours

“…There is well-documented evidence that oestradiol-17, induces glucose-6-phosphate dehydrogenase (GPDH) in both normal and neoplastic mammary tissue (Hilf et al, 1967;Ringler & Hilf, 1975). Furthermore, GPDH activity is higher in neoplastic tissue (Smith et al, 1966;Knox, 1967;Richards & Hilf, 1972) and neoplastic mammary tissue contains higher oestrogen-receptor concentrations than normal mammary tissue, thus suggesting a correlation between GPDH and oestrogen receptor (Daehnfeldt & Schulein, 1975). An increase in NADPH/NADP+, via raised GPDH levels, could then account for the increase in the rate of oestradiol-17, formation from oestrone in DMBA-induced tumours after oestrogen administration to oophorectomized animals.…”

Relationship between X Chromosome Activation, Barr Body Frequency and Oestrogen Receptor Status in Human Breast Cancer: a Hypothesis

“…In fact, it has been reported that in human breast carcinomas there is a correlation between high levels of the oestrogen recep tor protein and a high G6PD activity [4], It remains to be verified whether G6PD activity and the level of the oestrogen receptor both correlate with the sex chromatin frequency in breast cancer patients. If this is so, then G6PD activity and sex chromatin frequency might supplement information gained from oestrogen receptor assays for the selection of breast cancer pa tients who might respond favourably to hormonal therapy.…”