抄録
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 3.7S and the binding protein for 25 (OH) D3 at about 6.0S on sucrose density gradient analysis containing 0.3M KCI and 1mM dithiothreitol in buffer. Kd for 1.25 (OH)2D3 were from 0.1×10-11M to 7.17times;10-11M measured by Scatchard plots. Competition binding studies indicated that the relative specificity of the binding protein for 1.25 (OH) 2D3>25 (OH) D3<1α(OH) D3, 24, 25 (OH) 2D3>D3> Estradiol-177beta;. 1.25 (OH)2D3 receptor-positive was detected in twenty-eight out of thirty breast cancers.
