RESUMEN
Luminal breast cancer (BrCa) has a favorable prognosis compared with other tumor subtypes. However, with time, tumors may evolve and lead to disease progression; thus, there is a great interest in unraveling the mechanisms that drive tumor metastasis and endocrine resistance. In this review, we focus on one of the many pathways that have been involved in tumor progression, the fibroblast growth factor/fibroblast growth factor receptor (FGFR) axis. We emphasize in data obtained from in vivo experimental models that we believe that in luminal BrCa, tumor growth relies in a crosstalk with the stromal tissue. We revisited the studies that illustrate the interaction between hormone receptors and FGFR. We also highlight the most frequent alterations found in BrCa cell lines and provide a short review on the trials that use FGFR inhibitors in combination with endocrine therapies. Analysis of these data suggests there are many players involved in this pathway that might be also targeted to decrease FGF signaling, in addition to specific FGFR inhibitors that may be exploited to increase their efficacy.
Asunto(s)
Neoplasias de la Mama/tratamiento farmacológico , Factores de Crecimiento de Fibroblastos/fisiología , Receptores de Factores de Crecimiento de Fibroblastos/fisiología , Receptores de Esteroides/fisiología , Transducción de Señal/fisiología , Animales , Inhibidores de la Aromatasa/uso terapéutico , Neoplasias de la Mama/química , Neoplasias de la Mama/terapia , Línea Celular Tumoral , Quinasa 4 Dependiente de la Ciclina/antagonistas & inhibidores , Receptor alfa de Estrógeno/análisis , Femenino , Factores de Crecimiento de Fibroblastos/genética , Amplificación de Genes , Humanos , Ratones , Mutación , Receptor Cross-Talk/fisiología , Receptores de Factores de Crecimiento de Fibroblastos/antagonistas & inhibidores , Receptores de Factores de Crecimiento de Fibroblastos/genéticaRESUMEN
Progesterone receptors (PRs) ligands are being tested in luminal breast cancer. There are mainly two PR isoforms, PRA and PRB, and their ratio (PRA/PRB) may be predictive of antiprogestin response. Our aim was to investigate: the impact of the PR isoform ratio on metastatic behaviour, the PR isoform ratio in paired primary tumours and lymph node metastases (LNM) and, the effect of antiprogestin/progestins on metastatic growth. Using murine and human metastatic models, we demonstrated that tumours with PRB > PRA (PRB-H) have a higher proliferation index but less metastatic ability than those with PRA > PRB (PRA-H). Antiprogestins and progestins inhibited metastatic burden in PRA-H and PRB-H models, respectively. In breast cancer samples, LNM retained the same PRA/PRB ratio as their matched primary tumours. Moreover, PRA-H LNM expressed higher total PR levels than the primary tumours. The expression of NDRG1, a metastasis suppressor protein, was higher in PRB-H compared to PRA-H tumours and was inversely regulated by antiprogestins/progestins. The binding of the corepressor SMRT at the progesterone responsive elements of the NDRG1 regulatory sequences, together with PRA, impeded its expression in PRA-H cells. Antiprogestins modulate the interplay between SMRT and AIB1 recruitment in PRA-H or PRB-H contexts regulating NDRG1 expression and thus, metastasis. In conclusion, we provide a mechanistic interpretation to explain the differential role of PR isoforms in metastatic growth and highlight the therapeutic benefit of using antiprogestins in PRA-H tumours. The therapeutic effect of progestins in PRB-H tumours is suggested.
Asunto(s)
Neoplasias de la Mama , Proteínas de Ciclo Celular , Péptidos y Proteínas de Señalización Intracelular , Receptores de Progesterona , Animales , Neoplasias de la Mama/patología , Proteínas de Ciclo Celular/metabolismo , Femenino , Humanos , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Ratones , Metástasis de la Neoplasia , Progesterona/farmacología , Progestinas/metabolismo , Isoformas de Proteínas/metabolismo , Receptores de Progesterona/metabolismoRESUMEN
Progesterone receptors (PR) play a pivotal role in many female reproductive tissues such as the uterus, the ovary, and the mammary gland (MG). Moreover, PR play a key role in breast cancer growth and progression. This has led to the development and study of different progestins and antiprogestins, many of which are currently being tested in clinical trials for cancer treatment. Recent reviews have addressed the role of PR in MG development, carcinogenesis, and breast cancer growth. Thus, in this review, in addition to making an overview on PR action in normal and tumor breast, the focus has been put on highlighting the still unresolved topics on hormone treatment involving PR isoforms and breast cancer prognosis.
Asunto(s)
Neoplasias de la Mama , Receptores de Progesterona , Mama/patología , Neoplasias de la Mama/tratamiento farmacológico , Femenino , Humanos , Progesterona/uso terapéutico , Progestinas/uso terapéutico , Receptores de Progesterona/uso terapéuticoRESUMEN
Anti-Müllerian hormone (AMH) is secreted by Sertoli cells of the testes from early fetal life until puberty, when it is downregulated by androgens. In conditions like complete androgen insensitivity syndrome (CAIS), AMH downregulation does not occur and AMH increases at puberty, due in part to follicle-stimulating hormone (FSH) effect. However, other conditions like Peutz-Jeghers syndrome (PJS), characterised by low FSH, also have increased AMH. Because both CAIS and PJS may present as hyperoestrogenic states, we tested the hypothesis that oestradiol (E2) upregulates AMH expression in peripubertal Sertoli cells and explored the molecular mechanisms potentially involved. The results showed that E2 is capable of inducing an upregulation of endogenous AMH and of the AMH promoter activity in the prepubertal Sertoli cell line SMAT1, signalling through ERα binding to a specific ERE sequence present on the hAMH promoter. A modest action was also mediated through the membrane oestrogen receptor GPER. Additionally, the existence of ERα expression in Sertoli cells in patients with CAIS was confirmed by immunohistochemistry. The evidence presented here provides biological plausibility to the hypothesis that testicular AMH production increases in clinical conditions in response to elevated oestrogen levels.
Asunto(s)
Síndrome de Resistencia Androgénica/metabolismo , Hormona Antimülleriana/metabolismo , Receptor alfa de Estrógeno/biosíntesis , Proteínas de Neoplasias/biosíntesis , Síndrome de Peutz-Jeghers/metabolismo , Elementos de Respuesta , Células de Sertoli/metabolismo , Síndrome de Resistencia Androgénica/patología , Animales , Línea Celular , Niño , Preescolar , Estradiol/metabolismo , Femenino , Humanos , Masculino , Ratones , Síndrome de Peutz-Jeghers/patología , Células de Sertoli/patologíaRESUMEN
The superposition of male sexual characteristics in female marine gastropods (imposex) represents one of the clearest ecological examples of organotin-mediated endocrine disruption. Recent evidences suggest that signaling pathways mediated by members of the nuclear receptor superfamily, RXR and PPARγ, are involved in the development of this pseudohermaphroditic condition. Here, we identified significant differences in RXR expression in two caenogastropod species from Nuevo Gulf, Argentina, Buccinanops globulosus and Trophon geversianus, which present clear contrast in imposex incidence. In addition, B. globulosus males from a polluted and an unpolluted area showed differences in RXR expression. Conversely, PPARγ levels were similar between both analyzed species. These findings indicate specie-specific RXR and PPARγ expression, suggesting a major role of RXR in the induction of imposex.
Asunto(s)
Trastornos del Desarrollo Sexual/metabolismo , Gastrópodos , Regulación del Desarrollo de la Expresión Génica , Receptores X Retinoide/metabolismo , Animales , Susceptibilidad a Enfermedades , Trastornos del Desarrollo Sexual/patología , Femenino , Masculino , PPAR gamma/metabolismoRESUMEN
Progression to hormone-independent growth leading to endocrine therapy resistance occurs in a high proportion of patients with estrogen receptor alpha (ERα) and progesterone receptors (PR) positive breast cancer. We and others have previously shown that estrogen- and progestin-induced tumor growth requires ERα and PR interaction at their target genes. Here, we show that fibroblast growth factor 2 (FGF2)-induces cell proliferation and tumor growth through hormone-independent ERα and PR activation and their interaction at the MYC enhancer and proximal promoter. MYC inhibitors, antiestrogens or antiprogestins reverted FGF2-induced effects. LC-MS/MS identified 700 canonical proteins recruited to MYC regulatory sequences after FGF2 stimulation, 397 of which required active ERα (ERα-dependent). We identified ERα-dependent proteins regulating transcription that, after FGF2 treatment, were recruited to the enhancer as well as proteins involved in transcription initiation that were recruited to the proximal promoter. Also, among the ERα-dependent and independent proteins detected at both sites, PR isoforms A and B as well as the novel protein product PRBΔ4 were found. PRBΔ4 lacks the hormone-binding domain and was able to induce reporter gene expression from estrogen-regulated elements and to increase cell proliferation when cells were stimulated with FGF2 but not by progestins. Analysis of the Cancer Genome Atlas data set revealed that PRBΔ4 expression is associated with worse overall survival in luminal breast cancer patients. This discovery provides a new mechanism by which growth factor signaling can engage nonclassical hormone receptor isoforms such as PRBΔ4, which interacts with growth-factor activated ERα and PR to stimulate MYC gene expression and hence progression to endocrine resistance.
Asunto(s)
Neoplasias de la Mama/metabolismo , Receptor alfa de Estrógeno/metabolismo , Factor 2 de Crecimiento de Fibroblastos/metabolismo , Proteínas Proto-Oncogénicas c-myc/genética , Receptores de Progesterona/metabolismo , Animales , Neoplasias de la Mama/genética , Neoplasias de la Mama/patología , Línea Celular Tumoral , Proliferación Celular , Elementos de Facilitación Genéticos , Femenino , Regulación Neoplásica de la Expresión Génica , Humanos , Células MCF-7 , Ratones , Pronóstico , Regiones Promotoras Genéticas , Mapas de Interacción de Proteínas , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Receptores de Progesterona/genética , Análisis de Supervivencia , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
There is emerging interest in understanding the role of progesterone receptors (PRs) in breast cancer. The aim of this study was to investigate the proliferative effect of progestins and antiprogestins depending on the relative expression of the A (PRA) and B (PRB) isoforms of PR. In mifepristone (MFP)-resistant murine carcinomas antiprogestin responsiveness was restored by re-expressing PRA using demethylating agents and histone deacetylase inhibitors. Consistently, in two human breast cancer xenograft models, one manipulated to overexpress PRA or PRB (IBH-6 cells), and the other expressing only PRA (T47D-YA) or PRB (T47D-YB), MFP selectively inhibited the growth of PRA-overexpressing tumors and stimulated IBH-6-PRB xenograft growth. Furthermore, in cells with high or equimolar PRA/PRB ratios, which are stimulated to proliferate in vitro by progestins, and are inhibited by MFP, MPA increased the interaction between PR and the coactivator AIB1, and MFP favored the interaction between PR and the corepressor SMRT. In a PRB-dominant context in which MFP stimulates and MPA inhibits cell proliferation, the opposite interactions were observed. Chromatin immunoprecipitation assays in T47D cells in the presence of MPA or MFP confirmed the interactions between PR and the coregulators at the CCND1 and MYC promoters. SMRT downregulation by siRNA abolished the inhibitory effect of MFP on MYC expression and cell proliferation. Our results indicate that antiprogestins are therapeutic tools that selectively inhibit PRA-overexpressing tumors by increasing the SMRT/AIB1 balance at the CCND1 and MYC promoters.
Asunto(s)
Ciclina D1/genética , Neoplasias Mamarias Experimentales/tratamiento farmacológico , Mifepristona/farmacología , Progestinas/metabolismo , Proteínas Proto-Oncogénicas c-myc/genética , Receptores de Progesterona/metabolismo , Animales , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Femenino , Humanos , Neoplasias Mamarias Experimentales/metabolismo , Neoplasias Mamarias Experimentales/patología , Ratones , Ratones Endogámicos BALB C , Ratones Desnudos , Co-Represor 2 de Receptor Nuclear/metabolismo , Coactivador 3 de Receptor Nuclear/metabolismo , Regiones Promotoras GenéticasRESUMEN
Hormone receptors represent the earliest biomarkers used in breast cancer not only as prognosis markers but, in addition, to decide treatment. However, mostly estrogen receptors have been used as therapeutic targets. There is compelling evidence indicating that progesterone receptors (PRs) play a hierarchical role in breast cancer growth and that they might be potentially used to improve the success of endocrine treatments. The two PR isoforms, PR-A and PR-B, play differential roles in regulating gene expression. Tumors overexpressing one or other PR isoform may respond different to endocrine treatment. In this chapter, we highlight the evidence regarding progestins as promoters or inhibitors of cell proliferation in order to understand the dual role of PR in regulating tumor growth, underscoring thus the need of biomarkers to identify which patients may benefit with an antiprogestin/progestin treatment.
Asunto(s)
Antineoplásicos Hormonales/uso terapéutico , Neoplasias de la Mama/tratamiento farmacológico , Terapia Molecular Dirigida , Proteínas de Neoplasias/metabolismo , Receptores de Progesterona/metabolismo , Animales , Antineoplásicos Hormonales/farmacología , Neoplasias de la Mama/metabolismo , Proliferación Celular/efectos de los fármacos , Femenino , Humanos , Proteínas de Neoplasias/agonistas , Proteínas de Neoplasias/antagonistas & inhibidores , Progestinas/efectos adversos , Progestinas/metabolismo , Progestinas/farmacología , Progestinas/uso terapéutico , Receptores de Progesterona/agonistas , Receptores de Progesterona/antagonistas & inhibidoresRESUMEN
In C4-HD murine mammary carcinomas and in human breast cancer T47D cells, we showed that medroxyprogesterone acetate (MPA) induces a nuclear physical association between estrogen receptor alpha (ERa) and progesterone receptors (PR). The blockade of ERa inhibits cell proliferation mediated by progestins. We hypothesized that this nuclear association between ERa/PR is necessary to trigger progestin-induced cell proliferation and tumor growth. We demonstrated that fulvestrant (FUL, ICI182.780) induced complete regression of C4-HD tumors growing with progestins. MPA treatment induced an early increase in both CCND1 and MYC expression in T47D cells. The blockade of ERa prevented the MPA-dependent transcription of both genes. Specific binding of PR/ERa was observed at the same MPA-sensitive regions at the CCND1 and MYC gene promoters after chromatin immunoprecipitation (ChIP) analysis. ICI inhibited binding of ERa to both gene regulatory sequences while PR binding was unaffected. The nuclear colocalization between both receptors in T47D cells was confirmed by: confocal microscopy, Duolink assays and co-immunoprecipitation assays. In breast cancer samples we also observed a nuclear interaction between both steroid receptors. Our results indicate that the presence of ERa interacting with activated PR at the CCND1 and MYC promoters is required to trigger progestin-induced gene transcription and cell proliferation in breast cancer cells.
Asunto(s)
Carcinoma/patología , Estradiol/análogos & derivados , Receptor alfa de Estrógeno/fisiología , Neoplasias Mamarias Experimentales/patología , Receptores de Progesterona/fisiología , Animales , Antineoplásicos Hormonales/farmacología , Neoplasias de la Mama/genética , Carcinoma/inducido químicamente , Carcinoma/tratamiento farmacológico , Proliferación Celular , Inmunoprecipitación de Cromatina , Ciclina D1/metabolismo , Estradiol/administración & dosificación , Receptor alfa de Estrógeno/efectos de los fármacos , Femenino , Fulvestrant , Genes myc , Humanos , Neoplasias Mamarias Experimentales/inducido químicamente , Neoplasias Mamarias Experimentales/tratamiento farmacológico , Acetato de Medroxiprogesterona/farmacología , Murinae , Progestinas/metabolismo , Receptores de Progesterona/efectos de los fármacos , Transcripción GenéticaRESUMEN
Synthetic progesterone used in contraception drugs (progestins) can promote breast cancer growth, but the mechanisms involved are unknown. Moreover, it remains unclear whether cytoplasmic interactions between the progesterone receptor (PR) and estrogen receptor alpha (ERα) are required for PR activation. In this study, we used a murine progestin-dependent tumor to investigate the role of ERα in progestin-induced tumor cell proliferation. We found that treatment with the progestin medroxyprogesterone acetate (MPA) induced the expression and activation of ERα, as well as rapid nuclear colocalization of activated ERα with PR. Treatment with the pure antiestrogen fulvestrant to block ERα disrupted the interaction of ERα and PR in vitro and induced the regression of MPA-dependent tumor growth in vivo. ERα blockade also prevented an MPA-induced increase in CYCLIN D1 (CCND1) and MYC expression. Chromatin immunoprecipitation studies showed that MPA triggered binding of ERα and PR to the CCND1 and MYC promoters. Interestingly, blockade or RNAi-mediated silencing of ERα inhibited ERα, but not PR binding to both regulatory sequences, indicating that an interaction between ERα and PR at these sites is necessary for MPA-induced gene expression and cell proliferation. We confirmed that nuclear colocalization of both receptors also occurred in human breast cancer samples. Together, our findings argued that ERα-PR association on target gene promoters is essential for progestin-induced cell proliferation.
Asunto(s)
Neoplasias de la Mama/patología , Ciclina D1/genética , Receptor alfa de Estrógeno/metabolismo , Genes myc , Neoplasias Mamarias Experimentales/patología , Receptores de Progesterona/metabolismo , Animales , Neoplasias de la Mama/genética , Neoplasias de la Mama/metabolismo , Procesos de Crecimiento Celular/genética , Núcleo Celular/genética , Núcleo Celular/metabolismo , Estradiol/análogos & derivados , Estradiol/farmacología , Receptor alfa de Estrógeno/antagonistas & inhibidores , Receptor alfa de Estrógeno/genética , Femenino , Fulvestrant , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Genes Reporteros , Humanos , Neoplasias Mamarias Experimentales/genética , Neoplasias Mamarias Experimentales/metabolismo , Acetato de Medroxiprogesterona/farmacología , Ratones , Ratones Endogámicos BALB C , Neoplasias Hormono-Dependientes/genética , Neoplasias Hormono-Dependientes/metabolismo , Neoplasias Hormono-Dependientes/patología , Regiones Promotoras Genéticas , Receptores de Progesterona/genéticaRESUMEN
Fibroblast growth factor (FGF) receptor 2 (FGFR-2) polymorphisms have been associated with an increase in estrogen receptor and progesterone receptor (PR)-positive breast cancer risk; however, a clear mechanistic association between FGFR-2 and steroid hormone receptors remains elusive. In previous works, we have shown a cross talk between FGF2 and progestins in mouse mammary carcinomas. To investigate the mechanisms underlying these interactions and to validate our findings in a human setting, we have used T47D human breast cancer cells and human cancer tissue samples. We showed that medroxyprogesterone acetate (MPA) and FGF2 induced cell proliferation and activation of ERK, AKT, and STAT5 in T47D and in murine C4-HI cells. Nuclear interaction between PR, FGFR-2, and STAT5 after MPA and FGF2 treatment was also showed by confocal microscopy and immunoprecipitation. This effect was associated with increased transcription of PRE and/or GAS reporter genes, and of PR/STAT5-regulated genes and proteins. Two antiprogestins and the FGFR inhibitor PD173074, specifically blocked the effects induced by FGF2 or MPA respectively. The presence of PR/FGFR-2/STAT5 complexes bound to the PRE probe was corroborated by using NoShift transcription and chromatin immunoprecipitation of the MYC promoter. Additionally, we showed that T47D cells stably transfected with constitutively active FGFR-2 gave rise to invasive carcinomas when transplanted into NOD/SCID mice. Nuclear colocalization between PR and FGFR-2/STAT5 was also observed in human breast cancer tissues. This study represents the first demonstration of a nuclear interaction between FGFR-2 and STAT5, as PR coactivators at the DNA progesterone responsive elements, suggesting that FGFRs are valid therapeutic targets for human breast cancer treatment.
Asunto(s)
Neoplasias de la Mama/genética , Neoplasias de la Mama/metabolismo , Regulación Neoplásica de la Expresión Génica , Receptor Tipo 2 de Factor de Crecimiento de Fibroblastos/metabolismo , Receptores de Progesterona/metabolismo , Factor de Transcripción STAT5/metabolismo , Animales , Antineoplásicos Hormonales/farmacología , Línea Celular Tumoral , Quinasas MAP Reguladas por Señal Extracelular/metabolismo , Femenino , Humanos , Acetato de Medroxiprogesterona/farmacología , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos NOD , Ratones SCID , Trasplante de NeoplasiasRESUMEN
Most breast carcinomas that are estrogen receptor (ER) and progesterone receptor (PR) positive respond initially to an endocrine therapy, but over time, they develop resistance (acquired hormone resistance). Others, however, fail to respond from the beginning (constitutive resistance). Overcoming hormone resistance is one of the major desirable aims in breast cancer treatment. Using the medroxyprogesterone acetate (MPA)-induced breast cancer mouse model, we have previously demonstrated that antiprogestin-responsive tumors show a higher expression level of PR isoform A (PRA) than PR isoform B (PRB), while tumors with constitutive or acquired resistance show a higher expression level of PRB. The aim of this study was to investigate whether PRA silencing in resistant tumors was due to PRA methylation. The CpG islands located in the PRA promoter and the first exon were studied by methylation-specific PCR (MSP) in six different tumors: two antiprogestin-responsive, two constitutive-resistant, and two with acquired resistance. Only in constitutive-resistant tumors, PRA expression was silenced by DNA methylation. Next, we evaluated the effect of a demethylating agent, 5-aza-2'-deoxycytidine, on PRA expression and antiprogestin responsiveness. In constitutive-resistant tumors, 5-aza-2'-deoxycytidine treatment in vitro and in vivo restored PRA expression and antiprogestin RU-486 responsiveness. Furthermore, high levels of DNA methyltransferase (Dnmts) 1 and 3b were detected in these tumors. In conclusion, our results suggest that methyltransferase inhibitors in combination with antiprogestins may be effective in the treatment of constitutive-resistant carcinomas with a high DNA methyltransferase level.
Asunto(s)
Metilación de ADN/efectos de los fármacos , Resistencia a Antineoplásicos , Receptores de Progesterona/genética , Animales , Apoptosis/efectos de los fármacos , Azacitidina/análogos & derivados , Azacitidina/farmacología , Técnicas de Cultivo de Célula , Línea Celular Tumoral , Técnicas de Cocultivo , Metilasas de Modificación del ADN/antagonistas & inhibidores , Decitabina , Femenino , Regulación Neoplásica de la Expresión Génica , Silenciador del Gen , Antagonistas de Hormonas/farmacología , Neoplasias Mamarias Experimentales/metabolismo , Neoplasias Mamarias Experimentales/patología , Ratones , Ratones Endogámicos BALB C , Mifepristona/farmacología , Mitosis/efectos de los fármacos , Trasplante de Neoplasias , Regiones Promotoras Genéticas , Receptores de Glucocorticoides/metabolismo , Receptores de Progesterona/metabolismo , Trasplante Heterólogo , Carga Tumoral/efectos de los fármacosRESUMEN
In this article, we demonstrate the expression of functional progesterone binding sites at the cell membrane in murine mammary carcinomas that are stimulated by progestins and inhibited by antiprogestins. Using confocal immunofluorescence, ligand binding and cell compartment-specific western blots, we were able to identify the presence of the classical progesterone receptors. Medroxyprogesterone acetate (MPA) and RU-486 (1 × 10(-11) and 1 × 10(-8) M) behaved as agonists activating extracellular signal-regulated kinases (ERKs) and progestin-regulated proteins, except for Cyclin D1 and Tissue factor which failed to increase with 1 × 10(-8) M RU-486, an experimental condition that allows PR to bind DNA. These results predicted a full agonist effect at low concentrations of RU-486. Accordingly, at concentrations lower than 1 × 10(-11) M, RU-486 increased cell proliferation in vitro. This effect was abolished by incubation with the ERK kinase inhibitor PD 98059 or by OH-tamoxifen. In vivo, at a daily dose of 1.2 µg/kg body weight RU-486 increased tumor growth, whereas at 12 mg/kg induces tumor regression. Our results indicate that low concentrations of MPA and RU-486 induce similar agonistic non-genomic effects, whereas RU-486 at higher concentrations may inhibit cell proliferation by genomic-induced effects. This suggests that RU-486 should be therapeutically administered at doses high enough to guarantee its genomic inhibitory effect.
Asunto(s)
Regulación Neoplásica de la Expresión Génica , Neoplasias Mamarias Animales/tratamiento farmacológico , Neoplasias Mamarias Animales/metabolismo , Mifepristona/agonistas , Mifepristona/farmacología , Progestinas/agonistas , Progestinas/uso terapéutico , Receptores de Progesterona/metabolismo , Animales , Femenino , Acetato de Medroxiprogesterona/farmacología , Ratones , Ratones Endogámicos BALB C , Microscopía Confocal/métodos , Microscopía Fluorescente/métodos , Trasplante de Neoplasias , Receptores de Progesterona/química , Esteroides/químicaRESUMEN
Over the past several years, we have been interested in understanding the mechanisms by which mammary carcinomas acquire hormone independence. We demonstrated that carcinoma associated fibroblasts participate in the ligand-independent activation of progesterone receptors inducing tumor growth. In this study, we used DNA microarrays to compare the gene expression profiles of tumors from the MPA mouse breast cancer model, one hormone-dependent (C4-HD) and one hormone-independent (C4-HI), using whole tumor samples or laser-captured purified stromal and epithelial cells obtained from the same tumors. The expression of selected genes was validated by immunohistochemistry and immunofluorescence assays. We identified 413 genes specifically expressed in tumor stroma. Eighty-five percent of these genes were upregulated, whereas the remaining 15% were downregulated in C4-HI relative to their expression in the C4-HD tumor stroma. Several matrix metallopeptidases were overexpressed in the C4-HI tumor microenvironment. On the other hand, 1100 genes were specifically expressed in the tumor parenchyma. Among them, the 29% were upregulated, whereas the remaining 71% were downregulated in C4-HI relative to C4-HD tumor epithelium. Steap, Pdgfc, Runx2, Cxcl9, and Sdf2 were among the genes with high expression in the C4-HI tumor parenchyma. Interestingly, Fgf2 was one of the few genes upregulated by MPA in C4-HD tumors, confirming its pivotal role in regulating tumor growth in this model. In conclusion, we demonstrate herein a gene expression profile that distinguishes both the epithelial and the stromal cells in mammary tumors with different hormone dependence, supporting the hypothesis that the tumor-associated stroma may contribute to hormone-independent tumor growth.
Asunto(s)
Antineoplásicos Hormonales/farmacología , Carcinoma/genética , Perfilación de la Expresión Génica , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Neoplasias Mamarias Experimentales/genética , Acetato de Medroxiprogesterona/farmacología , Animales , Carcinoma/metabolismo , Carcinoma/patología , Análisis por Conglomerados , Células Epiteliales/efectos de los fármacos , Células Epiteliales/metabolismo , Femenino , Neoplasias Mamarias Experimentales/metabolismo , Neoplasias Mamarias Experimentales/patología , Ratones , Ratones Endogámicos BALB C , Reproducibilidad de los Resultados , Células del Estroma/efectos de los fármacos , Células del Estroma/metabolismoRESUMEN
We have previously demonstrated a crosstalk between fibroblast growth factor 2 (FGF2) and progestins inducing experimental breast cancer growth. The aim of the present study was to compare the effects of FGF2 and of medroxyprogesterone acetate (MPA) on the mouse mammary glands and to investigate whether the antiprogestin RU486 was able to reverse the MPA- or FGF2-induced effects on both, mammary gland and tumor growth. We demonstrate that FGF2 administered locally induced an intraductal hyperplasia that was not reverted by RU486, suggesting that FGF2-induced effects are progesterone receptor (PR)-independent. However, MPA-induced paraductal hyperplasia was reverted by RU486 and a partial agonistic effect was observed in RU486-treated glands. Using C4-HD tumors which only grow in the presence of MPA, we showed that FGF2 administered intratumorally was able to stimulate tumor growth as MPA. The histology of FGF2-treated tumors showed different degrees of gland differentiation. RU486 inhibited both, MPA or FGF2 induced tumor growth. However, only complete regression was observed in MPA-treated tumors. Our results support the hypothesis that stromal FGF2 activates PR inducing hormone independent tumor growth.
Asunto(s)
Factor 2 de Crecimiento de Fibroblastos/antagonistas & inhibidores , Antagonistas de Hormonas/farmacología , Glándulas Mamarias Animales/efectos de los fármacos , Neoplasias Mamarias Animales/tratamiento farmacológico , Acetato de Medroxiprogesterona/antagonistas & inhibidores , Mifepristona/farmacología , Animales , Modelos Animales de Enfermedad , Femenino , Hiperplasia/inducido químicamente , Glándulas Mamarias Animales/patología , Neoplasias Mamarias Animales/inducido químicamente , RatonesRESUMEN
To evaluate the extent to which each estrogen receptor (ER) subtype contributes to the stimulation or to the inhibition of mammary tumor growth, we evaluated the effects of specific agonists in MC4-L2 cells, which are stimulated by 17ß-estradiol (E(2)), and in mammary carcinomas of the MPA mouse breast cancer model, which are inhibited by E(2). Both express ERα and ERß. In MC4-L2 cells, 4,4',4"-(4-propyl-(1H)-pyrazole-1,3,5-triyl)trisphenol (PPT; ERα agonist) and (4-hydroxy-phenyl)-propionitrile (DPN; ERß agonist) stimulated cell proliferation, whereas the opposite occurred in C4-HI primary cultures. The inhibitory effect was associated with a decrease in ERα and cyclin D1 expression and an increase in progesterone receptor (PR) expression as well as in the Bax/Bcl-xl ratio. In vivo, mice carrying C4-HI or 32-2-HI tumors were treated with E(2), PPT or DPN (3 mg/kg/day) or with vehicle. PPT and DPN inhibited tumor size, as did E(2), during the first 72 h. After a few days, DPN-treated tumors started to grow again, while PPT-treated tumors remained quiescent for a longer period of time. A pronounced decrease in the mitotic index and an increase in the apoptotic index was associated with tumor regression. All treated tumors showed: (a) an increase in integrin α6 and Bax expression, (b) an increased stromal laminin redistribution, and (c) a decrease in ERα, Bcl-xl and Bcl-2 expression (P < 0.001). Apoptosis-inducing factor (Aif) expression was increased in DPN-treated tumors, while active caspase 9 was up-regulated in PPT-treated mice, demonstrating the involvement of the intrinsic apoptotic pathway in estrogen-induced regression in this model. In conclusion, our data indicate that although there may be some preferences for activation pathways by the different agonists, the stimulatory or inhibitory effects triggered by estrogens are cell-context dependent rather than ER isoform dependent.
Asunto(s)
Antineoplásicos Hormonales/farmacología , Neoplasias de la Mama/tratamiento farmacológico , Receptor alfa de Estrógeno/agonistas , Receptor beta de Estrógeno/agonistas , Nitrilos/farmacología , Fenoles/farmacología , Pirazoles/farmacología , Animales , Apoptosis/efectos de los fármacos , Factor Inductor de la Apoptosis/metabolismo , Neoplasias de la Mama/metabolismo , Neoplasias de la Mama/patología , Caspasa 9 , Proliferación Celular/efectos de los fármacos , Ciclina D1/metabolismo , Relación Dosis-Respuesta a Droga , Estradiol/farmacología , Receptor alfa de Estrógeno/metabolismo , Receptor beta de Estrógeno/metabolismo , Femenino , Ratones , Ratones Endogámicos BALB C , Receptores de Progesterona/metabolismo , Factores de Tiempo , Carga Tumoral , Células Tumorales Cultivadas , Proteína X Asociada a bcl-2/metabolismo , Proteína bcl-X/metabolismoRESUMEN
More than 60% of all breast neoplasias are ductal carcinomas expressing estrogen (ER) and progesterone receptors (PR). By contrast, most of the spontaneous, chemically or mouse mammary tumor virus induced tumors, as well as tumors arising in genetically modified mice do not express hormone receptors. We developed a model of breast cancer in which the administration of medroxyprogesterone acetate to BALB/c female mice induces mammary ductal carcinomas with a mean latency of 52 weeks and an incidence of about 80%. These tumors are hormone-dependent (HD), metastatic, express both ER and PR, and are maintained by syngeneic transplants. The model has been further refined to include mammary carcinomas that evolve through different stages of hormone dependence, as well as several hormone-responsive cell lines. In this review, we describe the main features of this tumor model, highlighting the role of PR as a trigger of key signaling pathways mediating tumor growth. In addition, we discuss the relevance of this model in comparison with other presently used breast cancer models pointing out its advantages and limitations and how, this model may be suitable to unravel key questions in breast cancer.
Asunto(s)
Carcinoma Ductal/metabolismo , Neoplasias Mamarias Experimentales/metabolismo , Neoplasias Hormono-Dependientes/metabolismo , Receptores de Progesterona/fisiología , Animales , Antineoplásicos Hormonales/toxicidad , Femenino , Neoplasias Mamarias Experimentales/patología , Acetato de Medroxiprogesterona/toxicidad , Ratones , Ratones Endogámicos BALB C , Receptores de Estrógenos/metabolismoRESUMEN
Breast cancer is the most frequent cancer in women. However, in vivo hormone receptor positive and metastatic models are scarce. The aim of the present manuscript was to assess if the novel steroid receptor positive human cell lines IBH-4, IBH-6, and IBH-7 developed in our laboratory from primary infiltrant ductal carcinomas are good models to study in vivo human breast cancer. Cell lines or tumors were inoculated to nude mice in the presence or absence of hormone supplementation. Growth was analyzed by ANOVA followed by Tukey-Kramer's test. Steroid hormone expression was assessed by immunohistochemistry and Western blotting. The histology of the tumors was analyzed. IBH-4 and IBH-6 cells were inoculated to nude mice and 100% of the injected mice developed tumors in the presence or absence of hormone treatment, although tamoxifen inhibited growth. IBH-4 and IBH-6 cell lines in vivo gave rise to poorly differentiated carcinomas with areas of solid growth and sarcomatoid areas showing no morphological signs of epithelial differentiation. Distinct features of malignancy were observed. IBH-7 tumors in animals receiving estradiol were semi-differentiated adenocarcinomas. IBH-7 cells grew only in the presence of estradiol, but even with hormone addition, the tumor take was 20%. These tumors metastasized to the uterus and lung and vascular tumor emboli were evident. IBH-7 tumors were invasive and able to break through the peritoneum. As a conclusion, IBH-4 and IBH-6 are good models for studying tumor progression, whereas IBH-7 is a good model for tumor take, being metastatic and strictly estrogen-dependent.
Asunto(s)
Neoplasias de la Mama , Línea Celular Tumoral/fisiología , Ratones Desnudos , Animales , Neoplasias de la Mama/metabolismo , Neoplasias de la Mama/patología , Técnicas de Cultivo de Célula , Línea Celular Tumoral/efectos de los fármacos , Antagonistas de Estrógenos/farmacología , Femenino , Humanos , Neoplasias Mamarias Experimentales/metabolismo , Neoplasias Mamarias Experimentales/patología , Ratones , Trasplante de Neoplasias , Tamoxifeno/farmacología , Trasplante HeterólogoRESUMEN
The mechanisms by which mammary carcinomas acquire hormone independence are still unknown. To study the role of cancer-associated fibroblasts (CAF) in the acquisition of hormone-independence we used a hormone-dependent (HD) mouse mammary tumor and its hormone-independent (HI) variant, which grows in vivo without hormone supply. HI tumors express higher levels of FGFR-2 than HD tumors. In spite of their in vivo differences, both tumors have the same hormone requirement in primary cultures. We demonstrated that CAF from HI tumors (CAF-HI) growing in vitro, express higher levels of FGF-2 than HD counterparts (CAF-HD). FGF-2 activated the progesterone receptors (PR) in the tumor cells, thus increasing cell proliferation in both HI and HD tumors. CAF-HI induced a higher proliferative rate on the tumor cells and in PR activation than CAF-HD. The blockage of FGF-2 in the co-cultures or the genetic or pharmacological inhibition of FGFR-2 inhibited PR activation and tumor cell proliferation. Moreover, in vivo, the FGFR inhibitor decreased C4-HI tumor growth, whereas FGF-2 was able to stimulate C4-HD tumor growth as MPA. T47D human breast cancer cells were also stimulated by progestins, FGF-2 or CAF-HI, and this stimulation was abrogated by antiprogestins, suggesting that the murine C4-HI cells respond as the human T47D cells. In summary, this is the first study reporting differences between CAF from HD and HI tumors suggesting that CAF-HI actively participate in driving HI tumor growth.
Asunto(s)
Neoplasias de la Mama/metabolismo , Neoplasias de la Mama/patología , Factor 2 de Crecimiento de Fibroblastos/farmacología , Progesterona/metabolismo , Receptor Tipo 2 de Factor de Crecimiento de Fibroblastos/metabolismo , Receptores de Progesterona/metabolismo , Animales , Proliferación Celular/efectos de los fármacos , Células Cultivadas , Técnicas de Cocultivo , Femenino , Fibroblastos , Regulación Neoplásica de la Expresión Génica , Humanos , Ratones , Ratones Endogámicos BALB C , Unión Proteica , Inhibidores de Proteínas Quinasas/farmacología , ARN Interferente Pequeño/genética , Receptor Tipo 2 de Factor de Crecimiento de Fibroblastos/antagonistas & inhibidores , Receptor Tipo 2 de Factor de Crecimiento de Fibroblastos/genética , Transducción de Señal/efectos de los fármacosRESUMEN
It has been proposed that progesterone (P4) induces the suppression of immune responses, particularly during pregnancy. However, knowledge about the mechanisms involved has remained largely elusive. We demonstrate herein that peripheral blood NK (PBNK) cells express both classical progesterone receptor (PR) isoforms and are specifically affected by the actions of P4 through two apparently independent mechanisms. Progesterone induces caspase-dependent PBNK cell death, which is reversed by two different anti-progestins, ZK 98.299 and RU 486, supporting the involvement of classical PR isoforms. It was suggested that CD56(bright)CD16(-) killer Ig-like receptor (KIR)(-) NK cells might represent precursor cells, which, upon activation, acquire the features of a more mature NK subset expressing KIR receptors. The present study demonstrates that PR expression seems to be restricted to more mature KIR(+) PBNK cells. The expression of PR had a functional counterpart in the suppressive effect of P4 on IL-12-induced IFN-gamma secretion. This cytokine suppression was mainly observed in KIR(+) PBNK cells, without affecting the high secretion of IFN-gamma by CD56(bright) PBNK cells. The lack of PR expression on CD56(bright)KIR(-) PBNK cells provides an additional phenotypic marker to test the idea that they might represent the PBNK precursors selectively recruited into the endometrium where they differentiate to become the uterine NK cells. Additionally, these findings may be relevant to NK cell function in viral immunity, human reproduction, and tumor immunity.