Long-term use of progestogens--getting the balance right: molecular biology and the endometrium

Dysfunctional uterine bleeding: from adolescence to menopause

Dysfunctional uterine bleeding (DUB) is defined as excessive or prolonged uterine bleeding in premenopausal women that is not caused by pelvic pathology, medications, systemic disease or pregnancy. It is a common condition that can lead not only to physical symptoms such as iron deficiency, anaemia, cramps and fatigue, but also has significant psychological and social effects that impair a woman's quality of life. Progesterone is highly important in the regulation of menstrual bleeding and a progesterone-deficient anovulatory state is a common cause of DUB. There are a wide range of treatment options available including hormonal therapies (oral cyclical progestogens, depot progestogens, progestogen-releasing intrauterine devices, combined oral contraceptives, danazol, gonadotrophin-releasing hormone analogues and hormone replacement therapy), non-hormonal therapies (non-steroidal anti-inflammatory drugs and antifibrinolytic drugs) and surgery (hysterectomy and endometrial ablation). The choice of appropriate therapy should be based on factors such as the mechanism behind the DUB, which symptoms are most problematic, and the woman's need for fertility or contraception. However, there is currently a lack of clinical evidence to help support these decisions.

Involvement of cyclin B1 in progesterone-mediated cell growth inhibition, G2/M cell cycle arrest, and apoptosis in human endometrial cell

BACKGROUND

Progesterone plays an important role in the proliferation and differentiation of human endometrial cells (hECs). Large-dose treatment with progesterone has been used for treatment of endometrial proliferative disorders. However, the mechanisms behind remain unknown.

METHODS

To investigate the role of cyclin B1 in proliferation and differentiation of hECs in menstrual cycle, the expression of cyclin B1 throughout the menstrual cycle was evaluated in hECs. To determine the effects of progesterone on the proliferation, cell cycle progression and apoptosis of hECs and to test if cyclin B1 is involved in these effects, progesterone and/or Alsterpaullone (Alp, a specific inhibitor of Cyclin B1/Cdc2) were added to primary hECs. Cellular proliferation was evaluated with MTT test, cell cycle with propidium iodide (PI) staining and flow cytometry, apoptosis with FITC-Annexin V and the expression of cyclin B1 with Western blotting.

RESULTS

The expression level of cyclin B1 in secretory endometria was significantly lower than in proliferative endometria (p < 0.01). Progesterone significantly inhibited the growth of hECs in a concentration-dependent manner (P < 0.01). The treatment with progesterone significantly decreased the expression of cyclin B1, increased the proportions of cell in G2/M phase, and apoptotic cells (P < 0.05 for all). The presence of Alp significantly enhanced the effects of progesterone on cyclin B1 down-regulation, G2/M cell cycle arrest and induction of apoptosis (P < 0.01 for all).

CONCLUSION

Our findings suggest that cyclin B1 is a critical factor in proliferation and differentiation of hECs. Progesterone may inhibit cell proliferation, mediate G2/M cell cycle arrest and induce apoptosis in hECs via down-regulating Cyclin B1.

Abnormal uterine bleeding: a focus on polycystic ovary syndrome

Abnormal uterine bleeding imposes major medical, social and financial problems for women, their families and the health services. Abnormal uterine bleeding refers to the regularity, frequency, duration and volume of bleeding. Irregular menstrual bleeding is most common at the extremes of reproductive life, in the initial 12-18 months after menarche and 5-6 years before the menopause begins. In Australia, the estimated cost of investigating and managing heavy menstrual bleeding alone is approximately AUS $6 million per annum. This article addresses the common causes of irregular bleeding in pre- and peri-menopausal women and presents an investigational approach.