The aim of these experiments was to investigate the expression of cyclin D1 and of oestradiol receptors as well as the level of [(3)H]oestradiol binding in leiomyoma and adjacent myometrium from human uteri at different menstrual phases and at an early stage of menopause. [(3)H]oestradiol binding was determined by saturation analysis, while the oestradiol receptor (ER) alpha and beta and cyclin D1 levels were determined by Western blot analysis of 16 samples of human leiomyomas and corresponding myometria at different hormonal stages. In leiomyomas during all phases of the menstrual cycle, ERalpha expression, high affinity oestradiol binding and cyclin D1 expression were all elevated in comparison with adjacent myometrium. ERbeta expression and low affinity oestradiol binding were enhanced in leiomyomas only during the proliferative phase. During menopause, ERbeta expression and low affinity binding were enhanced in leiomyomas, while the ERalpha expression was not significantly enhanced and cyclin D1 levels were similar to that in myometrium. Only the oestradiol binding exhibited any menstrual cycle-related changes. Our data suggest the involvement of cyclin D1 in the growth of leiomyomas during the menstrual cycle. In menopause, there appears to be a switch from ERalpha to ERbeta expression in leiomyomas, and the induction of cyclin D1 is decreased. The regression of tumour may ensue from these changes at menopause.

No abstract

No abstract

The effect of opioid peptides on cultured, oestradiol-stimulated human myometrial cells was examined. Oestradiol increased cell densities in mixed-cell (smooth muscle cells + stromal fibroblasts) cultures by 40%. This oestradiol-induced stimulation of cell proliferation was decreased to control values by D-met2-pro5-enkephalinamide. The half-effective inhibitory concentration of enkephalinamide was 0.3 nmol/l. The opioid-induced inhibition of cell proliferation was blocked completely by the specific opiate receptor antagonist naloxone, while naloxone did not have any effect on its own. This opioid effect was mediated dominantly by the mu opiate receptor. The optimal concentration for oestradiol to stimulate uterine cell proliferation was 2.2 nM. The basal rate of cell proliferation was not affected by enkephalinamide. In saturation experiments, the parameters of specific [3H]-naloxone binding were: dissociation constant = 1.02 nM, maximal binding capacity = 2910 binding sites/cell, Hill coefficient = 1.029. In human myometrial pure smooth muscle cell cultures, oestradiol decreased the proliferation of cells. Progesterone potentiated these oestradiol effects, but had no effect on its own. Enkephalinamide was also able to block the effects of oestradiol, but naloxone did not antagonize it. In summary, here we present a novel inhibitory role of endogenous opioid peptides in the regulation of cell growth and proliferation in the human uterus.

The aim of this study was to evaluate the nuclear expression of histone methyltransferase enhancer of zeste homolog 2 (EZH2) in endocervical neoplastic lesions such as invasive endocervical adenocarcinoma (ECA) and cervical in situ adenocarcinoma (AIS) in comparison with normal endocervix and non-neoplastic counterparts. A total of 54 consecutive neoplastic cases (37 ECA, 17 AIS) and 32 non-neoplastic endocervical lesions (15 reactive atypia, 9 microglandular hyperplasia, 3 tuboendometrioid metaplasia, 3 tunnel cluster, 2 endometriosis) were included in the study with adjacent normal endocervix if present. EZH2 immunoreactivity was evaluated semiquantitatively by three independent experts in lesions and adjacent normal glandular epithelium as well. EZH2 expression was defined robust if at least two of the three experts rated partial or diffuse positivity. Robust EZH2 expression was statistically compared among the neoplastic, non-neoplastic, and normal glandular epithelium samples. Diagnostic test capability of robust EZH2 expression was calculated. Fifty-three out of the 54 neoplastic cases (98%) showed robust EZH2 expression. Robust EZH2 expression was significantly less often (4 out of 32 cases, 12.5%) found in the non-neoplastic endocervical lesions ( p < 0.0001) and never (0 out of 66 samples) in the adjacent normal glandular epithelium. Robust EZH2 overexpression had a sensitivity and specificity of over 95% in detecting neoplastic lesions versus non-neoplastic lesions or normal glandular epithelium. EZH2 may play a role in the pathogenesis of endocervical neoplasia, and the detection of robust expression of EZH2 might be a useful differential diagnostic tool in problematic endocervical lesions in histology and cytology as well.