RESUMEN

PURPOSE: Expression of estrogen receptor alpha (ER) and/or progesterone receptor (PR) defines luminal breast cancer. Even though androgen (AR) and glucocorticoid receptors (GR) are highly expressed in luminal breast cancers, prognostic value remains uncertain and concomitant expression of these four hormone receptors is still unexplored. METHODS: Here, we evaluated ER, PR, AR, and GR expression, using immunohistochemistry, in a cohort of 169 breast cancer patients and correlated these findings with clinical and pathological parameters. RESULTS: We found that AR is more frequently expressed and at higher levels in the ER+PR- subset compared to ER+PR+ tumors. There were no significant differences in GR expression between tumor subsets. Moreover, most luminal tumors also expressed either AR or GR and most basal tumors were also negative for AR and GR. CONCLUSION: These data suggest that targeting AR in ER+PR- tumors may represent a promising therapeutic alternative in hormonal refractory tumors.

Asunto(s)

Neoplasias de la Mama/genética , Expresión Génica , Receptores Androgénicos/genética , Adulto , Anciano , Biomarcadores de Tumor , Neoplasias de la Mama/diagnóstico , Neoplasias de la Mama/metabolismo , Análisis por Conglomerados , Femenino , Frecuencia de los Genes , Humanos , Inmunohistoquímica , Persona de Mediana Edad , Clasificación del Tumor , Estadificación de Neoplasias , Receptores Androgénicos/metabolismo , Receptores de Estrógenos , Receptores de Progesterona

RESUMEN

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 Xenoinjerto

RESUMEN

Endocrine resistance may develop as a consequence of enhanced growth factor signaling. Fibroblast growth factor 2 (FGF2) consists of a low and several high molecular weight forms (HMW-FGF2). We previously demonstrated that antiprogestin-resistant mammary carcinomas display lower levels of progesterone receptor A isoforms (PRA) than B isoforms (PRB). Our aim was to evaluate the role of FGF2 isoforms in breast cancer progression. We evaluated FGF2 expression, cell proliferation, and pathway activation in models with different PRA/PRB ratios. We performed lentiviral infections of different FGF2 isoforms using the human hormone-responsive T47D-YA cells, engineered to only express PRA, and evaluated tumor growth, metastatic dissemination, and endocrine responsiveness. We assessed FGF2 expression and localization in 81 human breast cancer samples. Antiprogestin-resistant experimental mammary carcinomas with low PRA/PRB ratios and T47D-YB cells, which only express PRB, displayed higher levels of HMW-FGF2 than responsive variants. HMW-FGF2 overexpression in T47D-YA cells induced increased tumor growth, lung metastasis, and antiprogestin resistance compared to control tumors. In human breast carcinomas categorized by their PRA/PRB ratio, we found nuclear FGF2 expression in 55.6% of tumor cells. No differences were found between nuclear FGF2 expression and Ki67 proliferation index, tumor stage, or tumor grade. In low-grade tumor samples, moderate to high nuclear FGF2 levels were associated to carcinomas with low PRA/PRB ratio. In conclusion, we show that HMW-FGF2 isoforms are PRB targets which confer endocrine resistance and are localized in the nuclei of breast cancer samples. Hence, targeting intracellular FGF2 may contribute to overcome tumor progression.

Asunto(s)

Neoplasias de la Mama/genética , Factor 2 de Crecimiento de Fibroblastos/metabolismo , Animales , Neoplasias de la Mama/patología , Línea Celular Tumoral , Femenino , Humanos , Ratones , Peso Molecular

RESUMEN

Background: Compelling evidence shows that progestins regulate breast cancer growth. Using preclinical models, we demonstrated that antiprogestins are inhibitory when the level of progesterone receptor isoform A (PR-A) is higher than that of isoform B (PR-B) and that they might stimulate growth when PR-B is predominant. The aims of this study were to investigate ex vivo responses to mifepristone (MFP) in breast carcinomas with different PR isoform ratios and to examine their clinical and molecular characteristics. Methods: We performed human breast cancer tissue culture assays (n = 36) to evaluate the effect of MFP on cell proliferation. PR isoform expression was determined by immunoblotting (n = 282). Tumors were categorized as PRA-H (PR-A/PR-B ≥ 1.2) or PRB-H (PR-A/PR-B ≤ 0.83). RNA was extracted for Ribo-Zero-Seq sequencing to evaluate differentially expressed genes. Subtypes and risk scores were predicted using the PAM50 gene set, the data analyzed using The Cancer Genome Atlas RNA-seq gene analysis and other publicly available gene expression data. Tissue microarrays were performed using paraffin-embedded tissues (PRA-H n = 53, PRB-H n = 24), and protein expression analyzed by immunohistochemistry. All statistical tests were two-sided. Results: One hundred sixteen out of 222 (52.3%) PR+ tumors were PRA-H, and 64 (28.8%) PRB-H. Cell proliferation was inhibited by MFP in 19 of 19 tissue cultures from PRA-H tumors. A total of 139 transcripts related to proliferative pathways were differentially expressed in nine PRA-H and seven PRB-H tumors. PRB-H and PRA-H tumors were either luminal B or A phenotypes, respectively ( P = .03). PRB-H cases were associated with shorter relapse-free survival (hazard ratio [HR] = 2.70, 95% confidence interval [CI] = 1.71 to 6.20, P = .02) and distant metastasis-free survival (HR = 4.17, 95% CI = 2.18 to 7.97, P < .001). PRB-H tumors showed increased tumor size ( P < .001), Ki-67 levels ( P < .001), human epidermal growth factor receptor 2 expression ( P = .04), high grades ( P = .03), and decreased total PR ( P = .004) compared with PRA-H tumors. MUC-2 ( P < .001) and KRT6A ( P = .02) were also overexpressed in PRB-H tumors. Conclusion: The PRA/PRB ratio is a prognostic and predictive factor for antiprogestin responsiveness in breast cancer.

Asunto(s)

Neoplasias de la Mama/tratamiento farmacológico , Mifepristona/uso terapéutico , Progestinas/antagonistas & inhibidores , Receptores de Progesterona/metabolismo , Adulto , Anciano , Neoplasias de la Mama/genética , Neoplasias de la Mama/metabolismo , Proliferación Celular/efectos de los fármacos , Femenino , Perfilación de la Expresión Génica/métodos , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Antagonistas de Hormonas/uso terapéutico , Humanos , Immunoblotting , Inmunohistoquímica , Persona de Mediana Edad , Análisis de Secuencia por Matrices de Oligonucleótidos , Valor Predictivo de las Pruebas , Progestinas/metabolismo , Pronóstico , Análisis de Matrices Tisulares , Resultado del Tratamiento , Células Tumorales Cultivadas

RESUMEN

Mucinous carcinoma (MBC) is a rare subtype of breast cancer characterized by the production of variable amounts of mucin, with a prognosis better than that of non-mucinous carcinomas (NMBC). The aim of this project was to evaluate the expression of STAT-5, RUNX-2, and FGFR-2 in a cohort of MBC and compare it with that of NMBC using standard immunohistochemistry. STAT-5 and RUNX-2 are two transcription factors with cytoplasmic and/or nuclear localization that have been related to FGFR-2, a tyrosine kinase growth factor receptor that can interact with STAT-5 and with PR in the nuclei of breast cancer cells. Membranous, cytoplasmic, and nuclear staining were evaluated and expressed as the percentage of stained cells (0-100%) multiplied by the staining intensity (0-3), thus obtaining an index ranging from 0 to 300. Nuclear and/or cytoplasmic immunoreactivity of the three proteins were detected in a high number of NMBC. Nuclear FGFR-2 staining correlated with nuclear STAT-5 (p<0.05) and nuclear RUNX-2 (p<0.01) in both tumor types; however MBC had a significant higher expression of nuclear FGFR-2 (p<0.01) and RUNX-2 (p<0.05) than that of NMBC, and displayed positive immunoreactivity of the 3 proteins in 70.8% of the cases. These results suggest that these proteins may have a role in the progression of the mucinous phenotype, in which nuclear STAT-5 may inhibit RUNX-2 prometastatic effect.

Asunto(s)

Neoplasias de la Mama/metabolismo , Carcinoma Ductal de Mama/diagnóstico , Carcinoma Ductal de Mama/metabolismo , Subunidad alfa 1 del Factor de Unión al Sitio Principal/metabolismo , Receptor Tipo 2 de Factor de Crecimiento de Fibroblastos/metabolismo , Factor de Transcripción STAT5/metabolismo , Adenocarcinoma Mucinoso/metabolismo , Adenocarcinoma Mucinoso/patología , Neoplasias de la Mama/patología , Núcleo Celular/metabolismo , Femenino , Humanos , Inmunohistoquímica/métodos , Pronóstico

RESUMEN

Los estudios de hormona antimulleriana (HAM) e inhibina B tienen una implicancia importante en la fertilidad y salud sexual (su ausencia impide el embarazo) y en la salud ósea. Las investigaciones al respecto se realizaron en especial en endocrinología y reproducción desde 2000. Recientemente, ha llamado nuestra atención su estudio en diferentes centros mundiales en pacientes premenopáusicas con cáncer de mama temprano, posterior a la quimio y hormonoterapia, ya que su evaluación es un marcador, junto con la amenorrea, de la inactividad del ovario.

Asunto(s)

Neoplasias de la Mama , Quimioterapia , Hormonas , Inhibinas

RESUMEN

BACKGROUND: The etiology and the molecular mechanisms related to breast carcinogenesis remain poorly understood. Some recent reports have examined the role of Human Papillomavirus (HPV) in this disease. The purpose of this study was to determine the prevalence of HPV in breast cancer. METHODS: Sixty one fresh frozen breast cancers samples were analyzed. Samples were tested for HPV by PCR, and products were automatically sequenced. Findings were correlated with clinical and pathological characteristics. RESULTS: The HPV DNA prevalence in the breast cancer samples was 26% (16/61). Clinical parameters were not statistically associated with HPV presence (p>0.05 χ(2) test). Sequence analysis in a subgroup of cases indicates the prevalence of low risk HPV11, followed by high risk HPV16. We found no HPV transcriptional activity. CONCLUSION: The present study demonstrated for the first time in Argentina the presence of HPV in a proportion of the malignant breast tissues. This finding suggests that HPV may have a biological significance in breast carcinogenesis.

Asunto(s)

Neoplasias de la Mama/virología , Papillomavirus Humano 11/aislamiento & purificación , Papillomavirus Humano 11/fisiología , Papillomavirus Humano 16/aislamiento & purificación , Papillomavirus Humano 16/fisiología , Adulto , Anciano , Anciano de 80 o más Años , Argentina , Neoplasias de la Mama/patología , Femenino , Papillomavirus Humano 11/genética , Papillomavirus Humano 16/genética , Humanos , Persona de Mediana Edad , Riesgo

RESUMEN

We have previously described enhanced human breast cancer cell proliferation and mouse mammary tumor growth induced by α(2)-adrenoceptor (α(2)-AR) expression in epithelial cells. The aim of the present work was to assess if stromal fibroblasts can contribute to this effect. α(2)-AR expression was assessed by immunocytochemistry and immunohistochemistry, cell proliferation by [(3)H]-Thymidine incorporation and tumor growth by measuring with caliper. All tested mouse and human fibroblasts expressed at least two α(2)-AR subtypes and α(2)-adrenergic agonists enhanced fibroblast proliferation. In vivo, the α(2)-adrenergic agonist clonidine significantly enhanced tumor growth. The α(2)-adrenergic antagonist rauwolscine reversed this effect, but when administered alone, significantly inhibited tumor growth. Clonidine significantly stimulated cell proliferation in the epithelial-enriched fraction, the cancer associated fibroblast-enriched fraction and the co-culture of both fractions in primary cultures from both tumors (IBH-4 and IBH-6). Rauwolscine reversed clonidine stimulation in every fraction. However, when incubated alone, the inhibitory effect was observed in fractions from IBH-4 tumors but not from IBH-6 tumors. These experiments show that fibroblasts from tumor stroma are also influenced by α(2)-adrenergic compounds through the α(2)-ARs expressed in these cells. Moreover, the α(2)-adrenergic antagonist rauwolscine could eventually block in both epithelial and stromal cells, the mitogenic effect of catecholamines released during stress, providing a potential additional treatment for breast cancer patients. Chemists synthesizing adrenergic compounds should consider their action in breast cancer patients.

Asunto(s)

Agonistas de Receptores Adrenérgicos alfa 2/farmacología , Neoplasias Mamarias Experimentales/patología , Receptores Adrenérgicos alfa 2/metabolismo , Células del Estroma/patología , Antagonistas de Receptores Adrenérgicos alfa 2/farmacología , Animales , Neoplasias de la Mama/metabolismo , Neoplasias de la Mama/patología , Catecolaminas/farmacología , Línea Celular , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Clonidina/farmacología , Progresión de la Enfermedad , Células Epiteliales/efectos de los fármacos , Células Epiteliales/metabolismo , Células Epiteliales/patología , Femenino , Fibroblastos/citología , Fibroblastos/efectos de los fármacos , Fibroblastos/metabolismo , Humanos , Inmunohistoquímica , Neoplasias Mamarias Experimentales/metabolismo , Ratones , Ratones Endogámicos BALB C , Ratones Desnudos , Células del Estroma/efectos de los fármacos , Células del Estroma/metabolismo , Yohimbina/farmacología

RESUMEN

INTRODUCTION: Epstein-Barr virus (EBV)-associated tumors show different expression patterns of latency genes. Since in breast carcinoma this pattern is not yet fully described, our aim was to characterize EBV latency pattern in our EBV positive breast carcinoma series. METHODS: The study was conducted on 71 biopsies of breast carcinoma and in 48 non-neoplastic breast controls. EBNA1, LMP2A and LMP1 expression was assessed by immunohistochemistry with monoclonal antibodies, while viral genomic DNA and EBERs RNA transcripts expression was performed by in situ hybridization. EBV presence was confirmed by PCR. RESULTS: EBV genomic DNA and EBNA1 expression were detected in 31% (22/71) of patients specifically restricted to tumor epithelial cells in breast carcinoma while all breast control samples were negative for both viral DNA and EBNA1 protein. LMP2A was detected in 73% of EBNA1 positive cases, none of which expressed either LMP1 protein or EBERs transcripts. CONCLUSIONS: These findings suggest that EBV expression pattern in the studied biopsies could be different from those previously observed in breast carcinoma cell lines and lead us to suggest a new, EBNA1, LMP2A positive and LMP1 and EBERs negative latency profile in breast carcinoma in our population.

Asunto(s)

Neoplasias de la Mama/epidemiología , Herpesvirus Humano 4/aislamiento & purificación , Latencia del Virus , Argentina/epidemiología , Neoplasias de la Mama/virología , ADN Viral/genética , Herpesvirus Humano 4/genética , Herpesvirus Humano 4/fisiología , Humanos , Inmunohistoquímica , Hibridación in Situ , Reacción en Cadena de la Polimerasa

RESUMEN

CONTEXT: Because the etiology and progression of breast carcinoma remain unclear, novel mechanisms of disease pathogenesis need to be considered. Recent interest has focused on Epstein-Barr virus (EBV), an oncogenic ubiquitous herpesvirus. Investigations of this association could not only broaden understanding of breast cancer etiology but also have implications regarding early detection, treatment, and prevention. OBJECTIVE: To assess EBV presence in breast carcinoma in an Argentine series. DESIGN: Breast biopsy specimens of 69 women with breast carcinoma and fresh tumor tissue of 39 of these women were collected. As controls, 17 biopsy specimens of fibroadenomas, 9 of benign epithelial proliferation, 4 of atypical ductal hyperplasia, and 10 of usual ductal hyperplasia and 8 normal breast tissues from women were studied. The EBV-infected cells were identified by means of immunohistochemical analysis, using a monoclonal antibody against Epstein-Barr virus-encoded nuclear antigen 1 (EBNA-1). Polymerase chain reaction (PCR) was used to amplify EBV DNA, with primers that cover the EBV encoded RNA (EBER) and BamHIW regions. RESULTS: Nuclear expression of EBNA-1 was observed in tumor epithelial cells in 24 (35%) of the 69 cases. We confirmed both positive and negative immunohistochemical results by PCR in those cases where good quality DNA was also available, detecting amplification fragments of 108 base pairs (bp) from the EBER region and 122 bp from the BamHIW region. Neither immunohistochemical analysis nor PCR detected any positive EBV results in the control samples. CONCLUSIONS: Our results demonstrate the presence and expression of EBV restricted to epithelial tumor cells in a subset of breast carcinomas studied. However, no significant association was observed between EBV expression and worse clinical and pathologic patient characteristics.

Asunto(s)

Neoplasias de la Mama/virología , Carcinoma/virología , Infecciones por Virus de Epstein-Barr/complicaciones , Herpesvirus Humano 4/aislamiento & purificación , Anciano , Argentina , Femenino , Humanos

RESUMEN

Presentamos una casuística de 101 pacientes con cáncer avanzado de la mama, quienes fueron sometidas a cirugía ablativa hormonal en el Hospital Oncológico "Padre Machado", analizando edad, paridad, stadio clínico, tratamiento primario, intervalo libre, sitio de metástasis, tipo de cirugía ablativa, control y sobrevida

Asunto(s)

Adulto , Persona de Mediana Edad , Humanos , Femenino , Neoplasias de la Mama/terapia , Castración