title: Frequency of 1,25-dihydroxyvitamin D3 receptor in human breast cancer.
abstract: Receptors for 1,25-dihydroxyvitamin D3 have been shown to exist in cultured breast cancer cells and in primary breast cancers. It is reported here that 1,25-dihydroxyvitamin D3 receptor (1,25-DR) was present in 80% of 54 unselected breast cancers. The concentration of 1,25-DR in the 43 receptor-positive tumors was 1.9 +/- 0.4 fmol/mg protein (S.E.). There was no correlation between 1,25-DR presence or concentration and the age of the patient or the concentration of estrogen, progesterone, androgen, or glucocorticoid receptors. 1,25-DR was also found in two of three renal cortical carcinomas but only in three of 14 gastrointestinal tract carcinomas. The relatively low concentration of 1,25-DR in these breast cancers, compared with that found in cultured breast cancer cells, is partially explained by incomplete "exchange" with occupied receptors. Since the serum vitamin D-binding protein is not precipitated from serum itself or from tissue homogenates using the polyethylene glycol method, artifactual 1,25-DR levels due to the inevitable contamination of tissue specimens with this protein can be excluded. These findings indicate that 1,25-DR is not a nonspecific marker of cancer. The high frequency of 1,25-DR in the breast cancers may be related to the calcium-transporting ability of breast cancer cells which allows them to grow as osteolytic metastases.
mesh_terms: D000328:Adult; D001943:Breast Neoplasms / Q000378:metabolism*; D004100:Dihydroxycholecalciferols / Q000378:metabolism*; D005260:Female; D006801:Humans; D006887:Hydroxycholecalciferols / Q000378:metabolism*; D008593:Menopause; D018167:Receptors, Calcitriol; D011987:Receptors, Steroid / Q000378:metabolism*
chemical_list: D004100:Dihydroxycholecalciferols; D006887:Hydroxycholecalciferols; D018167:Receptors, Calcitriol; D011987:Receptors, Steroid