scholarly journals Reproductive tissue selective actions of progesterone receptors

Reproduction ◽  
2004 ◽  
Vol 128 (2) ◽  
pp. 139-146 ◽  
Author(s):  
Biserka Mulac-Jericevic ◽  
Orla M Conneely

The steroid hormone, progesterone, plays a central coordinate role in diverse events associated with female reproduction. In humans and other vertebrates, the biological activity of progesterone is mediated by modulation of the transcriptional activity of two progesterone receptors, PR-A and PR-B. These receptors arise from the same gene and exhibit both overlapping and distinct transcriptional activitiesin vitro. To delineate the individual roles of PR-A and PR-Bin vivo, we have generated mouse models in which expression of a single PR isoform has been ablated. Analysis of the reproductive phenotypes of these mice has indicated that PR-A and PR-B mediate mostly distinct but partially overlapping reproductive responses to progesterone. While selective ablation of the PR-A protein (PR-A knockout mice, PRAKO mice) shows normal mammary gland response to progesterone but severe uterine hyperplasia and ovarian abnormalities, ablation of PR-B protein (PRBKO mice) does not affect biological responses of the ovary or uterus to progesterone but results in reduced pregnancy-associated mammary gland morphogenesis. The distinct tissue-specific reproductive responses to progesterone exhibited by these isoforms are due to regulation of distinct subsets of progesterone-dependent target genes by the individual PR isoforms. This review will summarize our current understanding of the selective contribution of PR isoforms to the cellular and molecular actions of progesterone in reproductive tissues.

1982 ◽  
Vol 94 (1) ◽  
pp. 111-123 ◽  
Author(s):  
Y. Koseki ◽  
M. E. Costlow ◽  
D. Cole ◽  
A. Matsuzawa

The binding of [3H] 17,21-dimethyl-19-nor-4,9-pregnadiene-3,20-dione (R5020) to progesterone receptors in cytosol and nuclear extracts (0·6 m-KCl) of the pregnancy-dependent, TPDMT-4 mouse mammary tumour was measured at various stages of pregnancy. Compared with conventional dextran-coated charcoal (DCC) assays, a hydroxylapatite assay with DCC pretreatment and precharging of the cytosol with unlabelled R5020 (4 × 10−8 mol/l, for 3–4 h at 4 °C) showed the highest level of binding. The DCC treatment markedly increased the level of R5020 binding in both cytosol and nuclear extracts by allowing the receptor to bind to hydroxylapatite. The DCC pretreatment apparently removed a heat-stable and non-dialysable factor which prevented the receptor from binding to the hydroxylapatite. Using this assay R5020 binding reached a steady state in 24 h at 4 °C, with complete exchange of radioactive for non-radioactive ligand by 20 h. Nuclear extracts did not require precharging and complete exchange was more rapid. Scatchard analysis (without precharging) disclosed a single class of binding sites with a dissociation constant for cytosol of 3·2 ± 0·8 (s.e.m.) × 10−9 mol/l (n = 3) and 4·7 ± 0·6 × 10−9 mol/l (n = 5) for the nuclear extract. Binding was hormone-specific and progesterone translocated binding from the cytoplasm to the nucleus both in vivo and in vitro. Translocation, however, led to a substantial loss of total (nuclear + cytoplasmic receptors. During pregnancy, cytoplasmic progesterone receptor levels were unchanged and low compared to nuclear progesterone receptors which increased by sevenfold from days 1 to 11 and then decreased at day 16. Compared with recent data on cytoplasmic progesterone receptors in normal mammary gland, our results suggested that this tumour may have a reduced sensitivity to the down-regulatory activity of progesterone. This lesion may, in part, account for the failure of the tumour to differentiate during pregnancy.


2021 ◽  
Vol 11 ◽  
Author(s):  
Isaacson B. Adelani ◽  
Oluwakemi A. Rotimi ◽  
Emmanuel N. Maduagwu ◽  
Solomon O. Rotimi

Hepatocellular carcinoma (HCC) is a unique type of liver cancer instigated by underlying liver diseases. Pre-clinical evidence suggests that HCC progression, like other cancers, could be aided by vitamin D deficiency. Vitamin D is a lipid-soluble hormone usually obtained through sunlight. Vitamin D elucidates its biological responses by binding the vitamin D receptor; thus, promoting skeletal mineralization, and maintain calcium homeostasis. Other reported Vitamin D functions include specific roles in proliferation, angiogenesis, apoptosis, inflammation, and cell differentiation. This review highlighted studies on vitamin D’s functional roles in HCC and discussed the specific therapeutic targets from various in vivo, in vitro and clinical studies over the years. Furthermore, it described recent advancements in vitamin D’s anticancer effects and its metabolizing enzymes’ roles in HCC development. In summary, the review elucidated specific vitamin D-associated target genes that play critical functions in the inhibition of tumorigenesis through inflammation, oxidative stress, invasion, and apoptosis in HCC progression.


2000 ◽  
Vol 113 (12) ◽  
pp. 2129-2138 ◽  
Author(s):  
S. Naylor ◽  
M.J. Smalley ◽  
D. Robertson ◽  
B.A. Gusterson ◽  
P.A. Edwards ◽  
...  

Several Wnt genes are expressed in the postnatal mouse mammary gland and are thought to be involved in mammary gland development. Ectopic expression of Wnt-1, which is not normally expressed in the mammary gland, drives the formation of a pre-neoplastic hyperplasia. Cell culture-based assays have shown that Wnt-1 and some mammary-expressed Wnts transform C57MG cells. This has led to the suggestion that Wnt-1 functions as an oncogene through the inappropriate activation of developmental events that are normally controlled by the ‘transforming’ class of Wnts. In this study, Wnt-7b was expressed in vivo using recombinant retroviruses. Wnt-7b did not alter normal mammary gland development despite having similar effects to Wnt-1 in cell culture. We conclude that the in vitro classification of Wnts as ‘transforming’ does not correlate with the transformation in vivo. To facilitate the analysis of Wnt-expression, a lacZ-containing, bicistronic recombinant retrovirus was developed. Immunohistochemistry and electron microscopy identified retrovirally transduced myoepithelial and luminal epithelial cells in normal and hyperplastic tissues. The distribution of transduced cells in mammary outgrowths was consistent with current models of mammary stem cell identity.


1980 ◽  
Vol 86 (3) ◽  
pp. 730-737 ◽  
Author(s):  
S Z Haslam ◽  
G Shyamala

The biological basis for the observed modulation in cytoplasmic progesterone receptors (PgR) of normal mammary gland occurring during mammary development was investigated. Specifically, the relative roles of hormones vs. differentiation on (a) the decrease in PgR concentration during pregnancy and lactation and (b) the loss of mammary responsiveness to estrogen during lactation were examined. PgR were measured using the synthetic progestin, R5020, as the ligand. The hormones estrogen and progesterone were tested in vivo for their effect of PgR concentration. Mammary gland differentiation was assessed morphologically and by measuring enzymatically active alpha-lactalbumin. These studies show that there is a stepwise decrease in PgR that occurs in two stages. The first decrease is completed by day 12 of pregnancy and the second decrease occurs only after parturition. There appears to be a hormonal basis for the first decrease and it appears to be caused by the negative effect of progesterone on estrogen-mediated increase in PgR. In direct contrast, the absence of PgR during lactation and the mammary tissue insensitivity to estrogenic stimulation of PgR were not related to the hormonal milieu of lactation but were directly related to the secretory state of the mammary gland and lactation per se.


Molecules ◽  
2021 ◽  
Vol 26 (14) ◽  
pp. 4221
Author(s):  
Aage Kristian Olsen Alstrup ◽  
Svend Borup Jensen ◽  
Ole Lerberg Nielsen ◽  
Lars Jødal ◽  
Pia Afzelius

The development of new and better radioactive tracers capable of detecting and characterizing osteomyelitis is an ongoing process, mainly because available tracers lack selectivity towards osteomyelitis. An integrated part of developing new tracers is the performance of in vivo tests using appropriate animal models. The available animal models for osteomyelitis are also far from ideal. Therefore, developing improved animal osteomyelitis models is as important as developing new radioactive tracers. We recently published a review on radioactive tracers. In this review, we only present and discuss osteomyelitis models. Three ethical aspects (3R) are essential when exposing experimental animals to infections. Thus, we should perform experiments in vitro rather than in vivo (Replacement), use as few animals as possible (Reduction), and impose as little pain on the animal as possible (Refinement). The gain for humans should by far exceed the disadvantages for the individual experimental animal. To this end, the translational value of animal experiments is crucial. We therefore need a robust and well-characterized animal model to evaluate new osteomyelitis tracers to be sure that unpredicted variation in the animal model does not lead to a misinterpretation of the tracer behavior. In this review, we focus on how the development of radioactive tracers relies heavily on the selection of a reliable animal model, and we base the discussions on our own experience with a porcine model.


2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Junjie Cen ◽  
Yanping Liang ◽  
Yong Huang ◽  
Yihui Pan ◽  
Guannan Shu ◽  
...  

Abstract Background There is increasing evidence that circular RNAs (circRNAs) have significant regulatory roles in cancer development and progression; however, the expression patterns and biological functions of circRNAs in renal cell carcinoma (RCC) remain largely elusive. Method Bioinformatics methods were applied to screen for circRNAs differentially expressed in RCC. Analysis of online circRNAs microarray datasets and our own patient cohort indicated that circSDHC (hsa_circ_0015004) had a potential oncogenic role in RCC. Subsequently, circSDHC expression was measured in RCC tissues and cell lines by qPCR assay, and the prognostic value of circSDHC evaluated. Further, a series of functional in vitro and in vivo experiments were conducted to assess the effects of circSDHC on RCC proliferation and metastasis. RNA pull-down assay, luciferase reporter and fluorescent in situ hybridization assays were used to confirm the interactions between circSDHC, miR-127-3p and its target genes. Results Clinically, high circSDHC expression was correlated with advanced TNM stage and poor survival in patients with RCC. Further, circSDHC promoted tumor cell proliferation and invasion, both in vivo and in vitro. Analysis of the mechanism underlying the effects of circSDHC in RCC demonstrated that it binds competitively to miR-127-3p and prevents its suppression of a downstream gene, CDKN3, and the E2F1 pathway, thereby leading to RCC malignant progression. Furthermore, knockdown of circSDHC caused decreased CDKN3 expression and E2F1 pathway inhibition, which could be rescued by treatment with an miR-127-3p inhibitor. Conclusion Our data indicates, for the first time, an essential role for the circSDHC/miR-127-3p/CDKN3/E2F1 axis in RCC progression. Thus, circSDHC has potential to be a new therapeutic target in patients with RCC.


Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3532
Author(s):  
Ibrahim M. El-Deeb ◽  
Valeria Pittala ◽  
Diab Eltayeb ◽  
Khaled Greish

Triple-negative breast cancer (TNBC) is a heterogeneous subtype of tumors that tests negative for estrogen receptors, progesterone receptors, and excess HER2 protein. The mainstay of treatment remains chemotherapy, but the therapeutic outcome remains inadequate. This paper investigates the potential of a duocarmycin derivative, tafuramycin A (TFA), as a new and more effective chemotherapy agent in TNBC treatment. To this extent, we optimized the chemical synthesis of TFA, and we encapsulated TFA in a micellar system to reduce side effects and increase tumor accumulation. In vitro and in vivo studies suggest that both TFA and SMA–TFA possess high anticancer effects in TNBC models. Finally, the encapsulation of TFA offered a preferential avenue to tumor accumulation by increasing its concentration at the tumor tissues by around four times in comparison with the free drug. Overall, the results provide a new potential strategy useful for TNBC treatment.


2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii231-ii231
Author(s):  
Rachael Vaubel ◽  
Ann Mladek ◽  
Yu Zhao ◽  
Shiv K Gupta ◽  
Minjee Kim ◽  
...  

Abstract Non-genotoxic reactivation of p53 by MDM2 inhibitors represents a promising therapeutic strategy for tumors with wild-type TP53, particularly tumors harboring MDM2 amplification. MDM2 controls p53 levels by targeting it for degradation, while disruption of the MDM2-p53 interaction causes rapid accumulation of p53 and activation of the p53 pathway. We examined the efficacy of the small molecule MDM2 inhibitor KRT-232, alone and in combination with radiation therapy (RT), in MDM2-amplified and/or p53 wildtype patient-derived xenograft (PDX) models of glioblastoma in vitro and in vivo. In vitro, glioblastoma PDX explant cultures showed sensitivity to KRT-232, both tumors with MDM2 amplification (GBM108 and G148) and non-amplified but TP53-wildtype lines (GBM10, GBM14, and GBM39), with IC50s ranging from 300-800 nM in FBS culture conditions. A TP53 p.F270C mutant PDX (GBM43) was inherently resistant, with IC50 >3000 nM. In the MDM2-amplified GBM108 line, KRT-232 led to a robust (5-6 fold) induction of p53-target genes p21, PUMA, and NOXA, with initiation of both apoptosis and senescence. Expression of p21 and PUMA was greater with KRT-232 in combination with RT (25-35 fold induction), while stable knock-down of p53 in GBM108 led to complete resistance to KRT-232. In contrast, GBM10 showed lower induction of p21 and PUMA (2-3 fold) and was more resistant to KRT-232. In an orthotopic GBM108 xenograft model, treatment with KRT-232 +/- RT for one week extended survival from 22 days (placebo) to 46 days (KRT-232 alone); combination KRT-232 + RT further extended survival (77 days) over RT alone (31 days). KRT-232 is an effective treatment in a subset of glioblastoma pre-clinical models alone and in combination with RT. Further studies are underway to understand the mechanisms conferring innate sensitivity or resistance to KRT-232.


2021 ◽  
Vol 52 (1) ◽  
Author(s):  
Laurence Finot ◽  
Eric Chanat ◽  
Frederic Dessauge

AbstractIn vivo study of tissue or organ biology in mammals is very complex and progress is slowed by poor accessibility of samples and ethical concerns. Fortunately, however, advances in stem cell identification and culture have made it possible to derive in vitro 3D “tissues” called organoids, these three-dimensional structures partly or fully mimicking the in vivo functioning of organs. The mammary gland produces milk, the source of nutrition for newborn mammals. Milk is synthesized and secreted by the differentiated polarized mammary epithelial cells of the gland. Reconstructing in vitro a mammary-like structure mimicking the functional tissue represents a major challenge in mammary gland biology, especially for farm animals for which specific agronomic questions arise. This would greatly facilitate the study of mammary gland development, milk secretion processes and pathological effects of viral or bacterial infections at the cellular level, all with the objective of improving milk production at the animal level. With this aim, various 3D cell culture models have been developed such as mammospheres and, more recently, efforts to develop organoids in vitro have been considerable. Researchers are now starting to draw inspiration from other fields, such as bioengineering, to generate organoids that would be more physiologically relevant. In this chapter, we will discuss 3D cell culture systems as organoids and their relevance for agronomic research.


Cancers ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 159
Author(s):  
Tina Schönberger ◽  
Joachim Fandrey ◽  
Katrin Prost-Fingerle

Hypoxia is a key characteristic of tumor tissue. Cancer cells adapt to low oxygen by activating hypoxia-inducible factors (HIFs), ensuring their survival and continued growth despite this hostile environment. Therefore, the inhibition of HIFs and their target genes is a promising and emerging field of cancer research. Several drug candidates target protein–protein interactions or transcription mechanisms of the HIF pathway in order to interfere with activation of this pathway, which is deregulated in a wide range of solid and liquid cancers. Although some inhibitors are already in clinical trials, open questions remain with respect to their modes of action. New imaging technologies using luminescent and fluorescent methods or nanobodies to complement widely used approaches such as chromatin immunoprecipitation may help to answer some of these questions. In this review, we aim to summarize current inhibitor classes targeting the HIF pathway and to provide an overview of in vitro and in vivo techniques that could improve the understanding of inhibitor mechanisms. Unravelling the distinct principles regarding how inhibitors work is an indispensable step for efficient clinical applications and safety of anticancer compounds.


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