Testicular maturation arrest to testis cancer: spectrum of expression of the vitamin D receptor and vitamin D treatment in vitro.
OBJECTIVE
We investigated the qualitative distribution of vitamin D receptor in human testis pathologies and performed an in vitro study of vitamin D receptor expression in a human testis cancer cell line model.


METHODS
Qualitative immunohistochemical analysis of vitamin D receptor in testis tumors, normal testis and specimens from infertile patients was performed. The human embryonal carcinoma cell line NT2/D1 (American Type Culture Collection, Manassas, Virginia) was cultured. Vitamin D receptor expression was examined by Western immunoblot analysis after incubating the cells with 250 to 800 nM vitamin D, 10 to 70 nM testosterone, 2 nM calcium or a combination of the 3 products.


RESULTS
Negative controls, synctiotrophoblasts and interstitial stroma did not stain positive for vitamin D receptor. Spermatogenic, Sertoli's, Leydig and tumor cells stained positive in all specimens. Embryonal carcinoma demonstrated more nuclear and cytoplasmic staining than other tumors. Vitamin D receptor expression was seen at 50 kDa in the cell line. Sequential concentrations of vitamin D increased vitamin D receptor expression intensity. Simultaneous addition of vitamin D and testosterone decreased the vitamin D receptor signal, as did testosterone alone. Delayed administration of vitamin D 5 hours after testosterone showed the return of vitamin D receptor expression. A combination of calcium, testosterone and vitamin D showed decreased or no vitamin D receptor expression. Calcium alone increased vitamin D receptor expression at later passages.


CONCLUSIONS
To our knowledge this is the first description of vitamin D receptor in different primary testis pathologies and in an embryonal carcinoma cell line. The in vitro model showed that vitamin D receptor is an active receptor and it is inducible with the addition of vitamin D. Testosterone may be important for vitamin D receptor down-regulation. Calcium may be an important co-factor in vitamin D receptor expression.
Nangia
Ajay K
AK
Section of Urology and Department of Pathology, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire 03755, USA. ajay.k.nangia@hitchcock.org
Hill
Oya
O
Waterman
Maudine D
MD
Schwender
Catherine E B
CE
Memoli
Vince
V
D002118:Calcium / Q000494:pharmacology; D018236:Carcinoma, Embryonal / Q000378:metabolism; D045744:Cell Line, Tumor; D006801:Humans; D007150:Immunohistochemistry; D007248:Infertility, Male / Q000378:metabolism* / Q000503:physiopathology; D008297:Male; D018167:Receptors, Calcitriol / Q000378:metabolism*; D013091:Spermatogenesis; D013736:Testicular Neoplasms / Q000378:metabolism* / Q000503:physiopathology; D013737:Testis / Q000378:metabolism*; D013739:Testosterone / Q000494:pharmacology; D014807:Vitamin D / Q000494:pharmacology*
D018167:Receptors, Calcitriol; D014807:Vitamin D; D013739:Testosterone; D002118:Calcium