1,25-Dihydroxyvitamin D3Receptor Measurement in Primary Renal Cell Carcinomas and Autologous Normal Kidney Tissue1

Recently it was reported that l~«,25-dihydro\y vitamin O, [1,25iOH)zl),l inhibited cell growth in a cell Une derived from a metastasis from renal cell carcinoma. We have examined samples from 23 primary renal cell carcinomas for I,2S-(<)H)2D, 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) l,25-(OII)2n, 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-(()11)2D, receptor levels in the renal cell carcinomas were significantly lower than in the autologous normal kidney tissue (P < 0.001). The 1,25-(O11),!), receptor was characterized by sucrose gradient analysis and DNA-cellulose chromatography. The features found for renal cell carcinoma were similar to the l,25-(OH)jl)3 receptor in normal human tissue. No correlation of I,25-(OH)2I)3 recep tor 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)21), receptor. The receptor may have a cellular function in the transformed cell.