Estrogen and progestin are involved in ovarian carcinogenesis. Change in nm23-H1 expression and the PIK3/AKT pathway are involved in carcinogenesis, development, invasion and metastasis of ovarian cancers. Therefore, it is critical to understand the signaling pathways that regulate hormone-induced cell migration and invasion in ovarian cancer. We investigated nm23-H1, AKT and pAKT expression by...

Estrogen treatment of MCF-7 human breast cancer cells allows the reinitiation of synchronous cell cycle progression in antiestrogen-arrested cells. Here, we report that progestins also reinitiate cell cycle progression in this model. Using clonal cell lines derived from progesterone receptor (PR)-negative MCF-7M13 cells expressing wild-type or mutant forms of PRA and PRB, we show that this effe...

Using a highly potent synthetic-progestin, R5020 (17 alpha, 21-dimethyl-19-nor-4, 9-pregnadiene-3, 20-dione), the characterization of progestin binding components was attempted in cytosols from the anterior pituitary and various brain tissues of castrated or castrated-adrenalectomized male rats. In both types of operated rats, estrogen administration increased the number of binding sites of R50...

BACKGROUND In the Women's Health Initiative Randomized Controlled Trial (WHI RCT), estrogen-only treatment compared with combined estrogen-progestin treatment resulted in less coronary artery disease, no increase in breast cancer and no reduction in colorectal cancer. Since we previously reasonably replicated the combined estrogen-progestin WHI RCT using the UK General Practice Research Databas...

We evaluated colorectal cancer risk associated with the duration and recency of specific menopausal hormone therapy formulations (i.e., unopposed estrogen versus estrogen plus progestin) and regimens (i.e., sequential versus continuous estrogen plus progestin use) among 56,733 postmenopausal women participating in the Breast Cancer Detection Demonstration Project follow-up study. Hormone therap...

Meiosis is an indispensable process of sexual reproduction. However, detailed information on the regulatory mechanisms that initiate meiosis is not available. Progestins are important steroids regulating final maturation in male and female vertebrates. In male teleosts, it is known that progestin induces spermiation and sperm maturation. However, a role for progestin in early spermatogenesis or...

Zearalenone is a resorcylic acid lactone compound that is produced by fungal infection of edible grains and is believed to influence reproduction by binding to estrogen receptors. In order to study the potential estrogenic effects of this compound in the brain, we examined the effects of zearalenone on the expression of neuronal progestin receptors and feminine sexual behavior in female rats. O...

CDC's U.S. Medical Eligibility Criteria for Contraceptive Use (U.S. MEC) (first published in 2010 and updated in 2016) provides evidence-based guidance for the safe use of contraceptive methods among U.S. women with certain characteristics or medical conditions (1), and is adapted from global guidance from the World Health Organization (WHO) and kept up to date based on continual review of publ...

PURPOSE Clinical trials and epidemiological evidence have shown that combined estrogen/progestin hormone replacement therapy, but not estrogen therapy alone, increases breast cancer risk in post-menopausal women. Previously we have shown that natural and synthetic progestins, including the widely used synthetic progestin medroxyprogesterone acetate (MPA), increase production of a potent angioge...