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Ulipristal Acetate Inhibits Progesterone Receptor Isoform A-Mediated Human Breast Cancer Proliferation and BCl2-L1 Expression.

Esber N, Le Billan F, Resche-Rigon M, Loosfelt H, Lombès M, Chabbert-Buffet N - PLoS ONE (2015)

Bottom Line: P4 significantly stimulated MDA-iPRA expressing cells proliferation.UPA decreased cell proliferation and repressed BCL2-L1 expression in the presence of PRA, correlating with PRA and SRC1 but not RNA Pol II recruitment.Further confirmation in the clinical setting is required.

View Article: PubMed Central - PubMed

Affiliation: Institut National de la Santé et de la Recherche Médicale, Unité Mixte de Recherche-Scientifique 1185, Faculté de Médecine Paris Sud, Le Kremlin-Bicêtre, France; Université Paris-Sud, Faculté de Médecine Paris Sud, Unité Mixte de Recherche-Scientifique 1185, Le Kremlin-Bicêtre, France; HRA-Pharma, Paris, France.

ABSTRACT
The progesterone receptor (PR) with its isoforms and ligands are involved in breast tumorigenesis and prognosis. We aimed at analyzing the respective contribution of PR isoforms, PRA and PRB, in breast cancer cell proliferation in a new estrogen-independent cell based-model, allowing independent PR isoforms analysis. We used the bi-inducible human breast cancer cell system MDA-iPRAB. We studied the effects and molecular mechanisms of action of progesterone (P4) and ulipristal acetate (UPA), a new selective progesterone receptor modulator, alone or in combination. P4 significantly stimulated MDA-iPRA expressing cells proliferation. This was associated with P4-stimulated expression of the anti-apoptotic factor BCL2-L1 and enhanced recruitment of PRA, SRC-1 and RNA Pol II onto the +58 kb PR binding motif of the BCL2-L1 gene. UPA decreased cell proliferation and repressed BCL2-L1 expression in the presence of PRA, correlating with PRA and SRC1 but not RNA Pol II recruitment. These results bring new information on the mechanism of action of PR ligands in controlling breast cancer cell proliferation through PRA in an estrogen independent model. Evaluation of PR isoforms ratio, as well as molecular signature studies based on PRA target genes could be proposed to facilitate personalized breast cancer therapy. In this context, UPA could be of interest in endocrine therapy. Further confirmation in the clinical setting is required.

No MeSH data available.


Related in: MedlinePlus

Progesterone-dependent activation of MDA-iPRA cell proliferation.(a) Schematic representation of the bi-inducible system inserted into the MDA-iPRAB cell line in which RSL1 and Dox selectively trigger expression of PRA and PRB isoform respectively, as previously described [6]. (b) PRA and/or PRB expression in MDA-iPRAB cell lines. MDA-iPRAB cells were incubated with DMSO or inducers, RheoSwitch Ligand (RSL1, 0.5 μM) and/or doxycycline (Dox, 2 μM) during 24 h. Western blot analysis of whole cell extracts was performed using anti-PR antibody recognizing both PR isoforms (Novocastra) or anti-tubulin antibody for sample loading control. (c) MDA-iPRAB cell proliferation assays were analyzed on day 1, 3 and 5. Data are expressed as fold induction compared to vehicle condition arbitrarily set at 1, and are means ± SEM from five independent cell cultures (n = 6 for each experiment. ** indicates p<0.01 compared to the vehicle-treated cells for each MDA-iPRAB cell line (non-parametric Mann Whitney t-tests).
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pone.0140795.g001: Progesterone-dependent activation of MDA-iPRA cell proliferation.(a) Schematic representation of the bi-inducible system inserted into the MDA-iPRAB cell line in which RSL1 and Dox selectively trigger expression of PRA and PRB isoform respectively, as previously described [6]. (b) PRA and/or PRB expression in MDA-iPRAB cell lines. MDA-iPRAB cells were incubated with DMSO or inducers, RheoSwitch Ligand (RSL1, 0.5 μM) and/or doxycycline (Dox, 2 μM) during 24 h. Western blot analysis of whole cell extracts was performed using anti-PR antibody recognizing both PR isoforms (Novocastra) or anti-tubulin antibody for sample loading control. (c) MDA-iPRAB cell proliferation assays were analyzed on day 1, 3 and 5. Data are expressed as fold induction compared to vehicle condition arbitrarily set at 1, and are means ± SEM from five independent cell cultures (n = 6 for each experiment. ** indicates p<0.01 compared to the vehicle-treated cells for each MDA-iPRAB cell line (non-parametric Mann Whitney t-tests).

Mentions: We used the recently established bi-inducible MDA-iPRAB cell model to study the impact of PR isoform on human breast cancer cell proliferation [6]. This model results from genetically modified MDA-MB-231 human breast cancer cell line (PR-), generating various stable cell lines, MDA-iPR-, iPRA and/or iPRB cells. Two non-steroidal inducible systems, Rheoswitch and T-Rex were inserted into the same plasmid pZX-TR [6] (S1A Fig) and transfected into MDA-MB-231 cells generating parental and stable “clone 250” cell line. Subsequently, clone 250 cells were stably transfected with the bi-inducible system, pRheoswitch-PRA and pTRex-PRB, as schematically depicted on Fig 1A and S1B Fig. This bi-inducible system allows a bi-conditional expression of both PR isoforms, PRA at 94 kDa and/or PRB at 114 kDa, upon addition of RSL1 and/or Doxycycline (Dox) for 24 h, respectively (Fig 1B), while in the non-induced DMSO vehicle condition, no PR isoform expression was detected.


Ulipristal Acetate Inhibits Progesterone Receptor Isoform A-Mediated Human Breast Cancer Proliferation and BCl2-L1 Expression.

Esber N, Le Billan F, Resche-Rigon M, Loosfelt H, Lombès M, Chabbert-Buffet N - PLoS ONE (2015)

Progesterone-dependent activation of MDA-iPRA cell proliferation.(a) Schematic representation of the bi-inducible system inserted into the MDA-iPRAB cell line in which RSL1 and Dox selectively trigger expression of PRA and PRB isoform respectively, as previously described [6]. (b) PRA and/or PRB expression in MDA-iPRAB cell lines. MDA-iPRAB cells were incubated with DMSO or inducers, RheoSwitch Ligand (RSL1, 0.5 μM) and/or doxycycline (Dox, 2 μM) during 24 h. Western blot analysis of whole cell extracts was performed using anti-PR antibody recognizing both PR isoforms (Novocastra) or anti-tubulin antibody for sample loading control. (c) MDA-iPRAB cell proliferation assays were analyzed on day 1, 3 and 5. Data are expressed as fold induction compared to vehicle condition arbitrarily set at 1, and are means ± SEM from five independent cell cultures (n = 6 for each experiment. ** indicates p<0.01 compared to the vehicle-treated cells for each MDA-iPRAB cell line (non-parametric Mann Whitney t-tests).
© Copyright Policy
Related In: Results  -  Collection

License
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pone.0140795.g001: Progesterone-dependent activation of MDA-iPRA cell proliferation.(a) Schematic representation of the bi-inducible system inserted into the MDA-iPRAB cell line in which RSL1 and Dox selectively trigger expression of PRA and PRB isoform respectively, as previously described [6]. (b) PRA and/or PRB expression in MDA-iPRAB cell lines. MDA-iPRAB cells were incubated with DMSO or inducers, RheoSwitch Ligand (RSL1, 0.5 μM) and/or doxycycline (Dox, 2 μM) during 24 h. Western blot analysis of whole cell extracts was performed using anti-PR antibody recognizing both PR isoforms (Novocastra) or anti-tubulin antibody for sample loading control. (c) MDA-iPRAB cell proliferation assays were analyzed on day 1, 3 and 5. Data are expressed as fold induction compared to vehicle condition arbitrarily set at 1, and are means ± SEM from five independent cell cultures (n = 6 for each experiment. ** indicates p<0.01 compared to the vehicle-treated cells for each MDA-iPRAB cell line (non-parametric Mann Whitney t-tests).
Mentions: We used the recently established bi-inducible MDA-iPRAB cell model to study the impact of PR isoform on human breast cancer cell proliferation [6]. This model results from genetically modified MDA-MB-231 human breast cancer cell line (PR-), generating various stable cell lines, MDA-iPR-, iPRA and/or iPRB cells. Two non-steroidal inducible systems, Rheoswitch and T-Rex were inserted into the same plasmid pZX-TR [6] (S1A Fig) and transfected into MDA-MB-231 cells generating parental and stable “clone 250” cell line. Subsequently, clone 250 cells were stably transfected with the bi-inducible system, pRheoswitch-PRA and pTRex-PRB, as schematically depicted on Fig 1A and S1B Fig. This bi-inducible system allows a bi-conditional expression of both PR isoforms, PRA at 94 kDa and/or PRB at 114 kDa, upon addition of RSL1 and/or Doxycycline (Dox) for 24 h, respectively (Fig 1B), while in the non-induced DMSO vehicle condition, no PR isoform expression was detected.

Bottom Line: P4 significantly stimulated MDA-iPRA expressing cells proliferation.UPA decreased cell proliferation and repressed BCL2-L1 expression in the presence of PRA, correlating with PRA and SRC1 but not RNA Pol II recruitment.Further confirmation in the clinical setting is required.

View Article: PubMed Central - PubMed

Affiliation: Institut National de la Santé et de la Recherche Médicale, Unité Mixte de Recherche-Scientifique 1185, Faculté de Médecine Paris Sud, Le Kremlin-Bicêtre, France; Université Paris-Sud, Faculté de Médecine Paris Sud, Unité Mixte de Recherche-Scientifique 1185, Le Kremlin-Bicêtre, France; HRA-Pharma, Paris, France.

ABSTRACT
The progesterone receptor (PR) with its isoforms and ligands are involved in breast tumorigenesis and prognosis. We aimed at analyzing the respective contribution of PR isoforms, PRA and PRB, in breast cancer cell proliferation in a new estrogen-independent cell based-model, allowing independent PR isoforms analysis. We used the bi-inducible human breast cancer cell system MDA-iPRAB. We studied the effects and molecular mechanisms of action of progesterone (P4) and ulipristal acetate (UPA), a new selective progesterone receptor modulator, alone or in combination. P4 significantly stimulated MDA-iPRA expressing cells proliferation. This was associated with P4-stimulated expression of the anti-apoptotic factor BCL2-L1 and enhanced recruitment of PRA, SRC-1 and RNA Pol II onto the +58 kb PR binding motif of the BCL2-L1 gene. UPA decreased cell proliferation and repressed BCL2-L1 expression in the presence of PRA, correlating with PRA and SRC1 but not RNA Pol II recruitment. These results bring new information on the mechanism of action of PR ligands in controlling breast cancer cell proliferation through PRA in an estrogen independent model. Evaluation of PR isoforms ratio, as well as molecular signature studies based on PRA target genes could be proposed to facilitate personalized breast cancer therapy. In this context, UPA could be of interest in endocrine therapy. Further confirmation in the clinical setting is required.

No MeSH data available.


Related in: MedlinePlus