24-25-dihydroxyvitamin-d-3 and Breast-Neoplasms

Vitamin D has long been prescribed as a supplement to breast cancer patients. This is partially motivated by data indicating that low serum vitamin D, measured as 25-hydroxyvitamin D3 [25(OH)D

Topics: 24,25-Dihydroxyvitamin D 3; Animals; Breast Neoplasms; Female; Humans; Mammary Neoplasms, Experimental; Receptors, Estrogen

Epidemiological studies indicate high serum 25(OH)D. NOD-SCID-IL2γR null female mice with MCF7 breast cancer xenografts in the mammary fat pad were treated with 24R,25(OH). 24R,25(OH). These results indicate that 24R,25(OH)

Topics: 24,25-Dihydroxyvitamin D 3; Animals; Breast Neoplasms; Cell Proliferation; Estradiol; Female; Humans; MCF-7 Cells; Mice; Mice, Inbred NOD; Phospholipase D; Receptors, Estrogen; Signal Transduction

Binding proteins for 1.25 (OH) 2D3 were investigated in thirty breast cancers. Human breast cancer was shown to contain specific, high affinity cytosol binding proteins for 1.25 (OH) 2D3 and 25 (OH) D3. The binding protein for 1.25 (OH) 2D3 sedimented at 3.7 S and the binding protein for 25 (OH) D3 at about 6.0 S on sucrose density gradient analysis containing 0.3 M KCl and 1 mM dithiothreitol in buffer. Kd for 1.25 (OH) 2D3 were from 0.1 x 10(-11) M to 7.1 x 10(-11) M measured by Scatchard plots. Competition binding studies indicated that the relative specificity of the binding protein for 1.25 (OH) 2D3 much greater than 25 (OH) D3 greater than 1 alpha (OH) D3, 24,25 (OH)2D3 greater than D3 much greater than Estradiol-17 beta. 1.25 (OH) 2D3 receptor-positive was detected in twenty-eight out of thirty breast cancers.

Topics: 24,25-Dihydroxyvitamin D 3; Binding, Competitive; Breast Neoplasms; Calcifediol; Calcitriol; Carrier Proteins; Centrifugation, Density Gradient; Cytosol; Dihydroxycholecalciferols; Female; Humans; Hydroxycholecalciferols; Kinetics; Receptors, Calcitriol; Receptors, Steroid; Vitamin D-Binding Protein