The effects of hormone therapy, estrogen therapy and tibolone on apoptosis and cyclin D1 expression in postmenopausal vaginal epithelium

OBJECTIVE: To investigate the effects of hormone therapy, estrogen therapy and tibolone on markers of apoptosis including bcl-2, and bax and cyclin D(1) expression in postmenopausal vaginal epithelium. STUDY DESIGN: Thirty postmenopausal women were randomized to the treatment protocols (0.625 mg conjugated equine estrogen (CEE) + 2.5 mg medroxyprogesterone acetate (MPA); 2mg estradiol valerate; 2.5mg tibolone). After baseline vaginal biopsy, control biopsies were performed after 70 days following the initiation of the therapy. Bcl-2, bax, Bcl-2/bax ratio, cyclin D(1) measurements were performed immunohistochemically. Data were analyzed by Kruskal-Wallis, Mann-Whitney U and Wilcoxon tests. RESULTS: After the treatment period the above-mentioned parameters were not different among the groups except for cyclin D(1) levels. Cyclin D(1) expression was found to be strong in patients with treated estradiol valerate. CONCLUSIONS: The effects of estrogen on cyclin D(1) expression were not detected with tibolone or with the addition of progesterone to estrogen in the vaginal epithelium. Cyclin D(1) appeared to have stronger effects on the estrogen related proliferation compared to apoptotic markers in vaginal epithelial cells.