RESUMEN
Cumulative exposure to estrogen (E) and progesterone (P) over the menstrual cycle significantly influences the risk of developing breast cancer. Despite the dogma that PR in the breast merely serves as a marker of an active estrogen receptor (ER), and as an inhibitor of the proliferative actions of E, it is now clear that in the breast P increases proliferation independently of E action. We show here that the progesterone receptor (PR) and ER are expressed in different epithelial populations, and target non-overlapping pathways in the normal human breast. In breast cancer, PR becomes highly correlated with ER, and this convergence is associated with signaling pathways predictive of disease metastasis. These data challenge the established paradigm that ER and PR function co-operatively in normal breast, and have significant implications not only for our understanding of normal breast biology, but also for diagnosis, prognosis and/or treatment options in breast cancer patients.
Asunto(s)
Biomarcadores de Tumor/metabolismo , Neoplasias de la Mama/metabolismo , Carcinoma Intraductal no Infiltrante/metabolismo , Transformación Celular Neoplásica/metabolismo , Células Epiteliales/metabolismo , Glándulas Mamarias Animales/metabolismo , Glándulas Mamarias Humanas/metabolismo , Receptores de Estrógenos/metabolismo , Receptores de Progesterona/metabolismo , Transducción de Señal , Animales , Biomarcadores de Tumor/genética , Neoplasias de la Mama/genética , Neoplasias de la Mama/mortalidad , Neoplasias de la Mama/patología , Carcinoma Intraductal no Infiltrante/genética , Carcinoma Intraductal no Infiltrante/mortalidad , Carcinoma Intraductal no Infiltrante/secundario , Estudios de Casos y Controles , Linaje de la Célula , Proliferación Celular , Transformación Celular Neoplásica/genética , Transformación Celular Neoplásica/patología , Células Epiteliales/patología , Femenino , Regulación Neoplásica de la Expresión Génica , Redes Reguladoras de Genes , Humanos , Estimación de Kaplan-Meier , Glándulas Mamarias Humanas/patología , Pronóstico , ARN Mensajero/metabolismo , Receptor Cross-Talk , Receptores de Estrógenos/genética , Receptores de Progesterona/genética , Factores de TiempoRESUMEN
The present studies explore the roles of vascular endothelial growth factor (VEGF) and estradiol on angiogenesis and stromal and epithelial cell proliferation in the marmoset endometrium during the proliferative phase of the ovulatory cycle. At the start of the proliferative phase, marmosets were 1) treated with vehicle, 2) treated with a VEGF inhibitor (VEGF Trap, aflibercept), 3) ovariectomized, 4) ovariectomized and given replacement estradiol, or 5) treated with VEGF Trap and given replacement estradiol. The uterus was examined 10 d later in the late proliferative phase. Changes in endothelial and epithelial cell proliferation were quantified using a volumetric density method after immunohistochemistry for bromodeoxyuridine to localize proliferating cells, CD31 to visualize endothelial cells, and dual staining to distinguish endothelial cell proliferation. Endothelial proliferation was elevated in late proliferative controls but virtually absent after VEGF Trap. Ovariectomy had a similar inhibitory effect, whereas angiogenesis was restored by estrogen replacement. Estradiol replacement in VEGF Trap-treated marmosets resulted in only a small increase in endothelial cell proliferation that remained significantly below control values. VEGF Trap treatment and ovariectomy also markedly reduced stromal cell proliferation but resulted in increased stromal cell density associated with a reduction in overall endometrial volume. Estrogen replacement in both ovariectomized and VEGF Trap-treated animals restored stromal proliferation rates and cell density. These results show that endometrial angiogenesis and stromal proliferation during the proliferative phase are driven by estradiol and that the effect of estrogen on angiogenesis is mediated largely by VEGF.
Asunto(s)
Proliferación Celular , Endometrio/irrigación sanguínea , Estradiol/fisiología , Neovascularización Fisiológica/fisiología , Factor A de Crecimiento Endotelial Vascular/fisiología , Animales , Callithrix , Proliferación Celular/efectos de los fármacos , Endometrio/citología , Endometrio/fisiología , Estradiol/farmacología , Femenino , Neovascularización Fisiológica/efectos de los fármacos , Tamaño de los Órganos , Ovariectomía , Factor A de Crecimiento Endotelial Vascular/antagonistas & inhibidoresRESUMEN
Thrombospondin (TSP)-1 is an antiangiogenic extracellular matrix glycoprotein that modulates several aspects of cellular function. The aim of this study was to determine the pattern of TSP-1 mRNA and protein expression as well as expression of its receptor CD36 in the marmoset ovary and to investigate the effects of inhibition of gonadotropins or VEGF activity on TSP-1 and CD36 expression in vivo. GnRH antagonist or VEGF Trap, a soluble decoy receptor, was administered on d 0 of the follicular phase of the cycle, and ovaries were collected at the end of the follicular phase (d 10). TSP-1 mRNA and protein were present in granulosa cells of preantral and antral follicles, with the highest staining at the late secondary and tertiary stages. Moreover, expression of TSP-1 mRNA and protein was significantly increased in tertiary follicles undergoing atresia. CD36 protein was detected in granulosa cells of preantral and antral follicles as well as in endothelial cells of large vessels. Inhibition of gonadotropin secretion or VEGF activity had no effect on TSP-1 expression; however, expression of CD36 protein was inhibited by the VEGF Trap. In conclusion, TSP-1 may be involved in the cessation of angiogenesis in follicles undergoing atresia; alternatively, TSP-1 may act on granulosa and/or endothelial cells to promote follicular atresia in the ovary. Angiogenesis is likely to involve a balance between pro- and antiangiogenic factors. Our results suggest that loss of VEGF activity does not regulate TSP-1 expression directly but may influence TSP-1 activity via down-regulation of the CD36 receptor.
Asunto(s)
Callithrix/genética , Atresia Folicular/genética , Ovario/metabolismo , Trombospondina 1/genética , Animales , Antígenos CD36/genética , Antígenos CD36/metabolismo , Callithrix/metabolismo , Femenino , Atresia Folicular/metabolismo , Regulación de la Expresión Génica/efectos de los fármacos , Hormona Liberadora de Gonadotropina/antagonistas & inhibidores , Antagonistas de Hormonas/farmacología , Ovario/efectos de los fármacos , ARN Mensajero/metabolismo , Receptores de Factores de Crecimiento Endotelial Vascular , Proteínas Recombinantes de Fusión/farmacología , Trombospondina 1/metabolismoRESUMEN
Marmosets are widely used, but detailed studies on localisation of endometrial oestrogen receptors alpha and beta (ER alpha and ER beta ), and the progesterone receptor (PR) are lacking. These receptors were localised and semi-quantitatively analysed throughout the ovulatory cycle, weeks 2, 3 and 4 of pregnancy and after treatment with GnRH antagonist, vascular endothelial growth factor (VEGF) Trap or ovariectomy. The PR in epithelial cells increased markedly between the mid- and late proliferative phases before declining in the mid-secretory phase and pregnancy. PR in stromal cells was present throughout the cycle and levels were maintained in pregnancy. ER alpha was present at the mid-proliferative phase and increased in glands at the late proliferative and early secretory phases, before declining at the late secretory phase and week 4 of pregnancy. Stromal ER alpha showed a similar trend, but decreased earlier, by the mid-secretory phase. ER beta was highly expressed in epithelial cells throughout the cycle and in pregnancy. In stroma, increases in ER beta expression were observed at the late proliferative phase with the staining index decreasing by half as the secretory phase progressed and in pregnancy. GnRH antagonist, VEGF Trap or ovariectomy caused significant reductions in PR and ER beta expression, but not in ER alpha when compared with the late proliferative phase of the normal cycle. Endothelial cells expressed ER beta , but not ER alpha or PR. It is concluded that the steroid receptor profile in the marmoset endometrium is generally similar to the human and should provide a useful model for studies on hormonal manipulation of the endometrium.