BACKGROUND In breast cancer cyclooxygenase-2 overexpression is related with poor outcomes, but the clinical relevance of cyclooxygenase-2 is still unclear. Progesterone receptor is a regulator of cyclooxygenase-2 expression. We postulate that progesterone receptor was associated to cyclooxygenase-2 expression and clinicopathologic factors in breast cancer. METHODS Cyclooxygenase-2 and progest...

Progesterone and its nuclear receptor are critical in modulating reproductive physiology and behavior in female and male vertebrates. Whiptail lizards (genus Cnemidophorus) are an excellent model system in which to study the evolution of sexual behavior, as both the ancestral and descendent species exist. Male-typical sexual behavior is mediated by progesterone in both the ancestral species and...

Previously, progesterone was found to regulate the initiation and biosynthetic rate of myelin synthesis in Schwann cell/neuronal cocultures. The mRNA for cytochrome P450scc (converts cholesterol to pregnenolone), 3beta-hydroxysteroid dehydrogenase (3beta-HSD, converts pregnenolone to progesterone), and the progesterone receptor were found to be markedly induced during active myelin synthesis. H...

Progesterone powerfully inhibits GnRH secretion in ewes, as in other species, but the neural mechanisms underlying this effect remain poorly understood. Visualization of the neural ovine progesterone receptor has proved elusive but, using a high temperature antigen unmasking technique, the progesterone receptor was revealed in the ewe brain. Progesterone receptors were located in the preoptic-h...

Monoclonal antibodies were used to investigate progesterone receptor structure (isoforms) in 33 primary human endometrial tumors. The monoclonal antibodies recognized on protein blots two progesterone receptor proteins with molecular weights of 116,000 and 81,000. The Mr 116,000 protein appeared as a triplet, while a single band was found for the Mr 81,000 protein. The triplet/singlet structure...

Putrescine, spermidine, and spermine are a group of small organic cations, collectively known as polyamines. They are present in all living cells, and their levels are generally increased in tumor cells. Progesterone receptor is a gene-regulatory protein that plays a major role in gestation and in hormonal responsiveness of breast cancer. We studied the effects of putrescine, spermidine, 2 lowe...

BACKGROUND Progesterone receptors play a key role in the development of canine mammary tumours, and recent research has focussed on their possible value as therapeutic targets using antiprogestins. Cloning and sequencing of the progesterone receptor gene has shown that the receptor has two isoforms, A and B, transcribed from a single gene. Experimental studies in human breast cancer suggest tha...

Taenia solium cysticercosis is a health problem in underdeveloped and developed countries. Sex hormones are involved in cysticercosis prevalence in female and male pigs. Here, we evaluated the effects of progesterone and its antagonist RU486 on scolex evagination, which is the initial step in the development of the adult worm. Interestingly, progesterone increased T. solium scolex evagination a...

background: the female breast is subjected to a lifetime of hormonal controls, whose effect is evident at the time of menarche and during the menstrual cycle, pregnancy and lactation. studies have reported multiple risk factors for breast cancer, some of which are a reflection of hormonally mediated events. the steroid receptors are also served as prognostic factors for evaluating status of mal...