25-Hydroxyvitamin D3 1alpha-hydroxylase splice variants in benign and malignant ovarian cell lines and tissue.

Calcitriol is judged to have a positive effect on control of the immune system, cell growth and differentiation and therefore, the prevention of cancer genesis. The aim of this study was to detect any possible differences in the 25-hydroxyvitamin D-1alpha-hydroxylase (1alphaOHase)-expression between benign and malignant ovarian tissue and cell lines. The analysis was conducted quantitatively, by means of nested "touchdown" PCR and Western blot, and qualitatively, with the use of real-time PCR and Western blot. The gene structure was sequenced. Compared to the benign cell line, the malignant cell lines showed a significantly higher expression of 1alphaOHase at the RNA level. A statistically lower expression of the 1alphaOHase protein was found in the malignant tissue. In the malignant cell lines and tissues, divergent bands were detected, which led to various splice variants on sequencing. Their increased expression in malignancy is possibly bound to the reduction of enzyme activity, which may lead to the genesis of ovarian cancer. In the future, preventive and therapeutic activities may result from these findings.

Expression of 25-hydroxyvitamin D3-24-hydroxylase in benign and malignant ovarian cell lines and tissue.

Calcitriol (1,25-dihydroxyvitamin D3, 1,25(OH)2D3) plays a pivotal role in maintaining calcium and phosphate homeostasis. Aside from that, it supports the native and attenuates the acquired immune system and has positive effects on cell growth, differentiation and the prevention of carcinogenesis. The goal of this study was to detect possible differences in the expression of the calcitriol-degrading enzyme 24-hydroxylase (24-OHase) between malignant and benign ovarian cell lines and tissue. The analyses were based on real-time PCR, nested touchdown PCR and Western blot. When compared to benign granulose GLZ cells, the malignant HGL5 cells showed a significantly higher 24-OHase expression at the protein level (p<0.01). In the malignant ovarian tissue, the expression was significantly higher in RNA (p<0.001), but lower at the protein level (p<0.01). An increased 24-OHase expression could indicate a decrease in available calcitriol.