Placental protein 14 in endometrium during menstrual cycle and effect of early luteal phase mifepristone administration on its expression in implantation stage endometrium in the rhesus monkey

Placental protein 14 (PP14) is a glycoprotein which is secreted by secretory phase endometrium and decidua in women, Despite the suggestion that PP14 is involved in the process of endometrial maturation for blastocyst implantation, our understanding in this regard is poor In the present study the concentrations and distribution patterns of immunodetectable PP14 in the endometrium during proliferative and secretory phases of normal ovulatory menstrual cycles, as well as in implantation stage endometrium in naturally mated ovulatory cycles,vith or without early luteal phase mifepristone treatment, mere investigated using the rhesus monkey as a primate model. Immunopositive PP14 was observed mainly in epithelial cells of glands and it was detected in one major immunopositive hand at M-r 28 kDa in tissue homogenate and spent medium. The area of immunopositive precipitation of PP14 in glands was minimal in follicular phase endometrium, and was higher (P < 0.01) in early, mid- and late luteal phase endometrium compared with that in pre- and periovulatory phases of the cycle, but there was no change in its area profile in the glandular compartment throughout the luteal phase. Immunopositivity for PP14 in luminal contents of gland displayed an increasing profile from early to late secretory phases. Thus, the concentrations and the distribution of immunodetectable PP14 in luteal phase endometrium of the rhesus monkey showed marked similarity with those of human endometrium during the natural menstrual cycle. Although there was no marked change in the hand characterstics for the protein in implantation stage endometrium following early luteal phase mifepristone treatment, it was markedly decreased (P < 0.01) in tissue homogenate and in vitro spent medium along with a lesser (P < 0.02) degree of immunoprecipitation in the glands in implantation stage samples of mifepristone treatment group compared with that in control group samples. Thus, the contragestional effect of early luteal phase mifepristone treatment appears to be associated with a decrease in the concentration of immunodetectable PP14 in implantation stage endometrial glands and its secretion in the rhesus monkey, It remains to be seen whether this decline is caused from direct antiprogesterone action on endometrial glands during progesterone dominance, or secondarily from associated retarded development of endometrium

Transcriptomic profile of normal breast tissue post-mifepristone treatment: secondary outcomes of a randomized controlled trial

Abstract Progesterone receptor antagonism is gaining attention due to progesterone’s recognized role as a major mitogen in breast tissue. Limited but promising data suggest the potential efficacy of antiprogestins in breast cancer prevention. The present study presents secondary outcomes from a randomized controlled trial and examine changes in breast mRNA expression following mifepristone treatment in healthy women. We analyzed 32 paired breast biopsies from 16 healthy premenopausal women at baseline and after two months of mifepristone treatment. In total, twenty-seven differentially expressed genes were identified, with enriched biological functions related to extracellular matrix remodeling. Notably, the altered gene signature induced by mifepristone in vivo was rather similar to the in vitro signature. Furthermore, this expression gene signature was associated with breast carcinogenesis and significantly correlated with progesterone receptor expression status in breast cancer, as validated in The Cancer Genome Atlas dataset using the R2 platform. The present study is the first to explore the breast transcriptome following mifepristone treatment in healthy breast tissue in vivo , enhancing the understanding of progesterone receptor antagonism and its potential protective effect against breast cancer by investigating its action in healthy breast tissue