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Endocrine, paracrine and intracrine mechanisms of growth regulation in normal and malignant breast epithelium
Published in A. R. Genazzani, Hormone Replacement Therapy and Cancer, 2020
J. R. Pasqualini, G. S. Chetrite
Other authors have obtained an increase of both the reductive and the oxidative 17ß-HSD activities with progesterone, medroxprogesterone acetate (MPA), levonorgestrel and norethisterone in MCF-7 cells57,58. MPA also stimulates these dual activities in ZR-75-1 cells, whereas Org 2058 increases the oxidative direction in T-47D cells59,60.
Immunohistochem1Cal Studies with Antibodies to the Chicken Oviduct Progesterone Receptor
Published in Louis P. Pertschuk, Sin Hang Lee, Localization of Putative Steroid Receptors, 2019
Jean-Marie Gase, Etienne-Emile Baulieu
As this part of the studies has been undertaken recently, only preliminary results are reported here. As in other tissues, PR in the brain and pituitary is under estrogenic control. For instance, IgG-RB revealed PR in many cells of the pars distalis and pars tuberalis of estradiol-treated male as well as female chickens (Figure 9). It is also possible to combine immunohistochemistry and autoradiography after administration of 3H-Org 2058. This comparison of the two techniques was carried out on the same frozen section of pituitary or brain.25 The exact congruence of the two populations of cells, which react with IgG-RB and concentrate 3H-Org 2058 in their nuclei, is a striking validation of the techniques to localize PR in target cells. Further studies are planned to show if PR-positive cells also secrete pituitary hormones, particularly LH. In the brain a complete mapping of PR-positive neurones is currently being performed, together with the dual localization of PR and LH-RH. Preliminary observations show the presence of PR in the preoptic area of estradiol-stimulated chickens (Figure 10).
In vitro modulation of multidrug resistance by pregnane steroids and in vivo inhibition of tumour development by 7α-OBz-11α(R)-OTHP-5β-pregnanedione in K562/R7 and H295R cell xenografts
Published in Journal of Enzyme Inhibition and Medicinal Chemistry, 2019
Ghina Alameh, Agnès Emptoz-Bonneton, Marc Rolland de Ravel, Eva L. Matera, Elisabeth Mappus, Patrick Balaguer, Luc Rocheblave, Thierry Lomberget, Charles Dumontet, Marc Le Borgne, Michel Pugeat, Catherine Grenot, Claude Y. Cuilleron
In order to evaluate the risks of unwanted side-effects, the four more potent 5α/β-pregnane modulators 3, 4, 6, and 9 were tested for their ability to activate PR as well as hPXR owing to its role in the expression of ABC transporters and drug-metabolising enzymes21. None of the steroids at concentrations up to their respective IC50 values was able to significantly compete with the reference PR ligand [3H]ORG2058 (Figure S1(A)). Measurements of the activation of hPXR by a luminescent assay23 revealed different but significant effects of the four steroids. Activation increased between 0.1 and 1 µM concentrations of modulators (Figure S1(B)), but never reached the level induced by the reference non-steroidal hPXR activator SR12813. The lowest effect was observed for the steroid modulator 4 up to a 5 µM concentration.