1,25-Dihydroxyvitamin D3 receptor measurement in primary renal cell carcinomas and autologous normal kidney tissue.

Recently it was reported that 1-alpha,25-dihydroxyvitamin D3 [1,25-(OH)2D3] inhibited cell growth in a cell line derived from a metastasis from renal cell carcinoma. We have examined samples from 23 primary renal cell carcinomas for 1,25-(OH)2D3 receptor content, and compared it with the concentrations in autologous normal kidney tissue. Nineteen of 23 (83%) renal cell carcinomas had detectable (above 1 fmol/mg protein) 1,25-(OH)2D3 receptor levels, and 15 of 23 (65%) had levels above 5 fmol/mg protein. Mean value for the renal cell carcinomas was 8.2 fmol/mg protein (range, 0-28 fmol/mg protein), and the mean value for autologous normal kidney tissue was 23.1 fmol/mg protein (range, 6.6-53.7 fmol/mg protein). The 1,25-(OH)2D3 receptor levels in the renal cell carcinomas were significantly lower than in the autologous normal kidney tissue (P less than 0.001). The 1,25-(OH)2D3 receptor was characterized by sucrose gradient analysis and DNA-cellulose chromatography. The features found for renal cell carcinoma were similar to the 1,25-(OH)2D3 receptor in normal human tissue. No correlation of 1,25-(OH)2D3 receptor levels to clinical parameters was found. This study shows that carcinomas originating from the kidney, the major vitamin D regulating organ, usually contain the 1,25-(OH)2D3 receptor. The receptor may have a cellular function in the transformed cell.