Vitamin D receptor expression in colorectal cancer.

AIMS To determine whether the vitamin D receptor is expressed in colorectal cancer, and its relation to stage of disease. METHODS Paraffin embedded sections of colorectal cancer from 30 patients who had undergone surgery were studied. Immunohistochemistry using the specific monoclonal antibody 9A7 gamma directed against the nuclear vitamin D receptor was used to identify receptors for the active metabolite of vitamin D3 (1,25-dihydroxyvitamin D3). RESULTS Microscopically normal human colorectal epithelium showed vitamin D receptor expression predominantly in the mid and upper crypts. All the colorectal cancer tissue studied showed vitamin D receptor expression, with a median of 25.3 (range 10.1 to 43.7) cells/graticule field (x 400). Although vitamin D receptor staining was heterogeneous within the individual cancers, neither Dukes stage nor the degree of differentiation appeared to influence expression of the receptor. CONCLUSIONS Colorectal cancer tissue expresses the nuclear vitamin D receptor and this could act as a potential therapeutic target for synthetic vitamin D3 differentiating agents.