CALCITONIN AND 1,25-DIHYDROXYVITAMIN D3 RECEPTORS IN HUMAN-BREAST CANCER CELL-LINES

Abstract

Five human breast cancer cell lines (MCF 7, T 47D, BT 20, MDA 157 and MDA 231) and a human breast epithelial cell line (HBL 100) contain specific high-affinity receptors for 1,25-dihydroxyvitamin D3. Kd values ranged from 0.6-2.0 .times. 10-11 M and receptor concentration from 31 to 150 fmol/mg cytosol protein. Two of the breast cancer lines (MCF 7 and T 47D) contain specific high-affinity receptors for calcitonin and a calcitonin-responsive adenylate cyclase, which were characterized with the aid of salmon, eel and human calcitonins and in several substituted analogues of human calcitonin. The 1,25-dihydroxyvitamin D3 receptor may reflect a normal property of the breast cell. Breast cancer cell lines provide a useful source of 1,25-dihydroxyvitamin D3 receptors. Their coexistence with a calcitonin receptor and biological response in some breast cancers offers the opportunity to investigate new aspects of breast cancer endocrinology.