Recently, vitamin D analogues have shown antineoplastic effect in several diseases. Vitamin D analogues exert its effect by interacting with the vitamin D receptor (VDR). Studies of VDR in transitional cell carcinoma (TCC) have not been reported. The purpose of the present study was therefore to examine whether human bladder tumor cells express VDR. Tumor biopsies were obtained from 26 patients with TCC. Expression of VDR was examined by immunohistochemical experiments. All tumors expressed VDR. Biopsies from advanced disease contained more VDR positive cells than low stage disease (p < 0.05). Similarly, also tumor grade appeared to be related to the number of cells expressing the receptor. Normal urothlium also expressed VDR but only with low intensity. Our study shows that TCC cells possess the VDR receptor which may make them capable to respond to stimulation with vitamin D, but functional studies of vitamin D's effect on TCC cells in vitro are necessary before the efficacy of treatment with vitamin D analogues in TCC can be evaluated in patients.
Scandinavian Journal of Urology and Nephrology, 1997, Vol 31, Issue 2, p. 161-6