Analysis of 1,25-dihydroxyvitamin D-3 receptors (VDR) in basal cell carcinomas

We have analyzed expression of 1,25-dihydroxyvitamin D-3 receptor (VDR) pro tein and mRNA in basal cell carcinomas (BCC) of human skin. VDR immunoreact ivity in BCCs was compared with the staining pattern of the proliferation m arker Ki-67 in the same tumors. Additionally, VDR staining was compared to staining pattern of apoptotic cells by terminal UTP nucleotide end labeling assay. Frozen sections of superficial type, nodular type, and fibrosing ty pe BCCs were consistently immunoreactive for VDR (mAb 9A7 gamma) with almos t every tumor cell labeled (n = 15), In general, VDR staining was pronounce d in peripheral tumor cells. VDR immunoreactivity was consistently stronger in tumor cells than in adjacent or unaffected epidermis. No visual correla tion was found in BCCs comparing labeling patterns of Ki-67-positive or apo ptotic cells and mAb 9A7 gamma. VDR mRNA was increased in BCCs (n = 6) comp ared to normal human skin (n = 5), as revealed by reverse transcription-pol ymerase chain reaction analysis. Our findings indicate that VDR is strongly expressed in BCCs and may be involved in the growth regulation of this tum our, and VDR mRNA and protein are increased in BCCs as compared to normal h uman epidermis.