1. Selective estrogen receptor modulators inhibit the effects of insulin-like growth factors in hyperparathyroidism
- Author
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Jeff M.P. Hilly, Claire E. Stewart, Teresa Lai, C. Wong, and J. R. Farndon
- Subjects
Adenoma ,Adult ,Male ,Selective Estrogen Receptor Modulators ,medicine.medical_specialty ,medicine.drug_class ,medicine.medical_treatment ,Blotting, Western ,Estrogen receptor ,Insulin-like growth factor ,Radioligand Assay ,Insulin-Like Growth Factor II ,Internal medicine ,medicine ,Tumor Cells, Cultured ,Estrogen Receptor beta ,Humans ,Insulin-Like Growth Factor I ,Receptor ,Aged ,DNA synthesis ,Estradiol ,business.industry ,Hyperparathyroidism ,Estrogen Receptor alpha ,Middle Aged ,Antiestrogen ,Tamoxifen ,Endocrinology ,Parathyroid Neoplasms ,Receptors, Estrogen ,Selective estrogen receptor modulator ,Estrogen ,Surgery ,Female ,business ,hormones, hormone substitutes, and hormone antagonists ,Cell Division ,medicine.drug - Abstract
Background. Primary hyperparathyroidism (HPT) predominately affects perimenopausal women, leading to speculations that an estrogen imbalance may be liable. We have previously demonstrated the importance of the insulin-like growth factor (IGF) axis in HPT. Because the antiestrogen tamoxifen has been shown to modulate the IGF axis, we examined the interactions of selective estrogen receptor modulators (SERMs) and IGF in HPT. Methods. Estrogen receptors were evaluated by Western immunoligand blotting. Sixteen parathyroid glands from 19 patients were included. After adhesion, the cells were treated with IGF (I or II) ± estrogen ± SERMs (tamoxifen, ICI 182,780) for 96 hours in serum-free media. Proliferation was assessed by measuring tritiated thymidine incorporation. Results. Both primary and secondary HPT express estrogen receptors α and β. Primary and secondary HPT had comparable responses to SERMs, they were analyzed together. Compared with control (100%), IGFs (I and II) induced a significant increase in DNA synthesis. Estradiol at 10−8 and 10−7 mol/L (physiologic range) had no significant effects on IGF (I and II, P > .05). Both tamoxifen and ICI 182,780 inhibited basal DNA synthesis (P < .05) and abolished the effects of both IGF I and II (P < .05). Conclusions. SERMs are capable of reducing basal and IGF-stimulated DNA synthesis. This reduction in proliferation has implications for cancer biology and therapeutic potential for SERMs in HPT.
- Published
- 2002