1,25-dihydroxyvitamin D3 receptors in human epithelial cancer cell lines.

Specific, high-affinity cytosolic receptors for 1,25-dihydroxyvitamin D3 have been demonstrated in five human cancer cell lines. The cell lines were derived from tumors of breast, lung, cervix, and melanotic and amelanotic melanomas. Binding affinity (Kd) of the receptors for 1,25-dihydroxyvitamin D3 were all approximately 0.2 nM, and receptor content ranged from 21 to 174 fmol/mg cytosol protein. The receptors from all five cell lines sedimented at 3.2S on sucrose density gradients and exhibited preferential affinity for 1,25-dihydroxyvitamin D3 compared to other vitamin D metabolites.