ABSTRACT
Corticotropin Releasing Factor (CRF) neuropeptides coordinate the stress response via two distinct membrane receptors (CRF-Rs). We have previously shown expression of both CRF-Rs in human breast cancer tissues. In the present study, we examined in vitro using the MCF-7 cell line model, the regulation of CRF-Rs expression and their signaling in hormone-dependent breast cancer growth. Our findings show that similarly to breast cancer biopsies, the predominant receptor type expressed in the cell line is CRF-R2α. The transcription of CRF-R1 and CRF-R2 is up and down-regulated respectively by exposure to estradiol (E2); however this effect seems not to be exerted at the level of promoter gene methylation, although in human breast cancer specimens, CRF-R1 methylation was found to be positively associated with the presence of steroid hormone receptors. Finally, we showed that specific activation of CRF-R2 increased the migration of MCF-7 cells and potentiated an estrogen-inducing effect. Our data support an involvement of CRF-R signaling in breast cancer pathophysiology via a regulatory steroid-hormone interplay.
Subject(s)
Breast Neoplasms/metabolism , Receptors, Corticotropin-Releasing Hormone/metabolism , Adult , Aged , Breast Neoplasms/genetics , Breast Neoplasms/pathology , Cell Line, Tumor , Cell Movement/genetics , Cell Movement/physiology , Cell Proliferation/genetics , Cell Proliferation/physiology , Fluorescent Antibody Technique , Humans , MCF-7 Cells , Middle Aged , Polymerase Chain Reaction , Real-Time Polymerase Chain ReactionABSTRACT
OBJECTIVE: The corticotropin-releasing factor (CRF) family consists of the neuropeptides CRF, Ucn I, II and III and the binding sites CRFR1, CRFR2 and CRF-BP. It regulates stress response and the homeostasis of an organism. In this study, we examined the presence of the CRF system in the human hearts of normal and pathological fetuses. DESIGN: Heart tissues from 40 archival human fetuses were divided into Group A (without pathology, 'normal'), Group B (with chromosomal abnormalities) and Group C (with congenital disorders). Immunohistochemistry was used to localize the CRF system. Results correlated to gestational trimester and pathology. RESULTS: Immunoreactivity for all antigens was found in cardiac myocytes of all groups, in almost all samples, except Ucn III which was present in almost half of the fetuses of Groups B and C and was not detected at all in Group A. Ucn III was more often present during the earlier stage of development (<21weeks) and in fetuses with congenital disorders. In a fetus diagnosed with heart pathology, all but Ucn III antigens were also present. CONCLUSIONS: We localized a complete CRF system in the human fetal heart and correlated the presence of Ucn III to development and pathology. More studies are needed to verify and clarify the exact role of the CRF system in the human fetal heart.
Subject(s)
Corticotropin-Releasing Hormone/metabolism , Fetal Heart/metabolism , Receptors, Corticotropin-Releasing Hormone/metabolism , Female , Gene Expression Regulation, Developmental/physiology , Gestational Age , Humans , Immunohistochemistry , Male , Receptors, Corticotropin-Releasing Hormone/genetics , Urocortins/genetics , Urocortins/metabolismABSTRACT
OBJECTIVE: The corticotropin-releasing factor (CRF) family consists of the neuropeptides CRF, Ucn I, II and III and the binding sites CRFR1, CRFR2 and CRF-BP. It regulates stress response and the homeostasis of an organism. In this study, we examined the presence of the CRF system in the human hearts of normal and pathological fetuses. DESIGN: Heart tissues from 40 archival human fetuses were divided into Group A (without pathology, 'normal'), Group B (with chromosomal abnormalities) and Group C (with congenital disorders). Immunohistochemistry was used to localize the CRF system. Results correlated to gestational trimester and pathology. RESULTS: Immunoreactivity for all antigens was found in cardiac myocytes of all groups, in almost all samples, except Ucn III which was present in almost half of the fetuses of Groups B and C and was not detected at all in Group A. Ucn III was more often present during the earlier stage of development (<21 weeks) and in fetuses with congenital disorders. In a fetus diagnosed with heart pathology, all but Ucn III antigens were also present. CONCLUSIONS: We localized a complete CRF system in the human fetal heart and correlated the presence of Ucn III to development and pathology. More studies are needed to verify and clarify the exact role of the CRF system in the human fetal heart.
ABSTRACT
OBJECTIVE: The Corticotropin Releasing Factor (CRF) system (neuropeptides CRF, Ucn I, II, III and binding sites CRFR1, CRFR2, CRF-BP) is responsible for stress regulation and the homeostasis of an organism. Herein we study the CRF system in human normal and pathological fetal lungs. DESIGN: Lung tissues from 46 archival human fetuses were divided into Group A (normal), Group B (chromosomal abnormalities) and Group C (congenital disorders). Presence of elements of the CRF system was evaluated using immunohistochemistry and was correlated to pathology, lung developmental stage and clinicopathological characteristics. RESULTS: Immunoreactivity for all antigens was found in both epithelial and mesenchymal lung cells of the bronchi and alveoli. Ucn I and CRFR1 were more frequently present in Group A. Ucns were more frequently localized at the pseudoglandular stage. There was a positive correlation between the presence of the CRF neuropeptides and between CRFR1 and CRF. Two fetuses with lung malformations showed low or no detectable presence of the CRF system. CONCLUSIONS: We report the presence of a complete CRF system in human fetal lungs correlating its developmental stage and several pathologies. Our results are in agreement with findings in experimental animal models, implicating the CRF system in fetal lung development, its action being more significant in the early stages.
Subject(s)
Chromosome Aberrations , Corticotropin-Releasing Hormone/analysis , Lung/chemistry , Respiratory System Abnormalities/metabolism , Signal Transduction , Carrier Proteins/analysis , Case-Control Studies , Female , Gestational Age , Humans , Immunohistochemistry , Lung/abnormalities , Male , Receptors, Corticotropin-Releasing Hormone/analysis , Respiratory System Abnormalities/embryology , Respiratory System Abnormalities/genetics , Urocortins/analysisABSTRACT
The corticotropin-releasing factor (CRF) system plays a crucial regulatory role in the adaptation to exogenous and endogenous stress stimuli, as well as homeostasis. Apart from the central nervous system (CNS), the members of this neuropeptide family extend their actions in the periphery, where they may affect various body systems independently, stimulating peripheral CRF receptors via vagal and/or autocrine/paracrine pathways. Here, we review all findings concerning the expression and role of the CRF system in human liver, but also in other species. Direct and indirect regulatory data are also analyzed in order to draw conclusions about possible physiological/pathophysiological implications. Although data supporting any clinical significance are still limited and further research in the field is necessary, scientific interest in the CRF system is particularly active, with multiple ongoing clinical studies evaluating the activity of CRF ligands in medical conditions involving other organs. Thus, new knowledge with therapeutic potential appears to be steadily accumulating.
Subject(s)
Allostasis , Corticotropin-Releasing Hormone/metabolism , Homeostasis , Liver/physiology , Pituitary Gland, Anterior/metabolism , Receptors, Corticotropin-Releasing Hormone/metabolism , Signal Transduction , Adaptation, Physiological , Adrenocorticotropic Hormone/metabolism , Animals , Corticotropin-Releasing Hormone/genetics , Gene Expression Regulation , Humans , Liver/physiopathology , Liver Diseases/etiology , Liver Diseases/metabolism , Liver Diseases/physiopathology , Receptors, Corticotropin-Releasing Hormone/genetics , Stress, Physiological , Stress, Psychological/physiopathology , Urocortins/genetics , Urocortins/metabolismABSTRACT
Expression of the two gonadotropin-releasing hormone homologue peptides GnRHI and GnRHII and their receptor GnRHR has been demonstrated in a number of malignancies. In hormone-dependent breast cancer, GnRH analogs are used for therapy in premenopausal women. Gene expression of GnRHI, II and R was studied in breast biopsies from primary breast adenocarcinoma obtained from the tumor and the adjacent benign tissue. Levels were evaluated by a multiplex real-time RT-PCR. GnRHI transcripts were detected in 14.7% of the benign and 29.4% malignant biopsies and GnRHII in 21.2% benign and 44.1% malignant biopsies. GnRHR was also more frequent in the malignant (54.2%) than in the benign (24.0%) biopsies, at similar expression levels. No transcripts were detected in biopsies from healthy individuals. There was a strong correlation between the presence of GnRHI and GnRHII transcripts and their receptor in the benign and the malignant biopsies. GnRHI, II and R expression correlated significantly with poor prognosis pathological parameters. Immunohistochemistry for GnRHR revealed expression in malignant cells and in epithelial cells of mammary ducts of the adjacent area with pre-cancerous features. In contrast, GnRH I and II peptides were rarely expressed at low levels in breast cancer cells. In conclusion GnRH peptides and receptor are expressed more frequently in breast tumors than in the adjacent mammary tissue, representing a malignant feature. Their expression correlated to tumor characteristics of poor prognosis and was therefore related to more aggressive malignancies. Concomitant expression of peptides and receptor supports an autocrine/paracrine regulating role.
