Urocortin expression is downregulated in human endometrial carcinoma

Urocortin-1 promotes colorectal cancer cell migration and proliferation and inhibits apoptosis via inhibition of the p53 signaling pathway

PURPOSE

To investigate the effect of urocortin-1 (UCN-1) on growth, migration, and apoptosis in colorectal cancer (CRC) in vivo and vitro and the mechanism by which UCN-1 modulates CRC cells in vitro.

METHODS

The correlation between UCN-1 and CRC was evaluated using The Cancer Genome Atlas (TCGA) database and a tissue microarray. The expression of UCN-1 in CRC cells was assessed using quantitative real-time polymerase chain reaction (RT-qPCR) and western blotting. In vitro, the influence of UCN-1 on the proliferation, apoptosis, and migration of HT-29, HCT-116, and RKO cells was explored using the celigo cell counting assay or cell counting kit-8 (CCK8), flow cytometry, and wound healing or Transwell assays, respectively. In vivo, the effect of UCN-1 on CRC growth and progression was evaluated in nude mice. The downstream pathway underlying UCN-1-mediated regulation of CRC was determined using the phospho-kinase profiler array in RKO cells. Lentiviruses were used to knockdown or upregulate UCN-1 expression in cells.

RESULTS

Both the TCGA and tissue microarray results showed that UCN-1 was strongly expressed in the tissues of patients with CRC. Furthermore, the tissue microarray results showed that the expression of UCN-1 was higher in male than in female patients, and high expression of UCN-1 was associated with higher risk of lymphatic metastasis and later pathological stage. UCN-1 knockdown caused a reduction in CRC cell proliferation, migration, and colony formation, as well as an increase in apoptosis. In xenograft experiments, tumors generated from RKO cells with UCN-1 knockdown exhibited reduced volumes and weights. A reduction in the expression of Ki-67 in xenograft tumors indicated that UCN-1 knockdown curbed tumor growth. The human phospho-kinase array showed that the p53 signaling pathway participated in UCN-1-mediated CRC development. The suppression in migration and proliferation caused by UCN-1 knockdown was reversed by inhibitors of p53 signal pathway, while the increase in cell apoptosis was suppressed. On the other hand, overexpression of UCN-1 promoted proliferation and migration and inhibited apoptosis in CRC cells. Overexpression of p53 reversed the effect of UCN-1 overexpression on CRC development.

CONCLUSION

UCN-1 promotes migration and proliferation and inhibits apoptosis via inhibition of the p53 signaling pathway.

The expression of corticotropin-releasing hormone family peptides in premalignant and malignant vulvar lesions

OBJECTIVES

To examine the relation of corticotropin-releasing hormone (CRH) family peptides with inflammatory processes and oncogenesis, emphasizing in vulvar inflammatory, premalignant and malignant lesions, as well as to investigate the possibility of lesion cells immunoescaping, utilizing FAS/FAS-L complex.

METHODS

Immunohistochemical expression of CRH, urocortin (UCN), FasL and their receptors CRHR1, CRHR2 and Fas was studied in vulvar tissue sections obtained from patients with histologically confirmed diagnosis of lichen, vulvar intraepithelial neoplasia (VIN) and vulvar squamous cell carcinoma (VSCC). The patient cohort was selected from a tertiary teaching Hospital in Greece, between 2005 and 2015. For each of the disease categories, immunohistochemical staining was evaluated and the results were statistically compared.

RESULTS

A progressive increase of the cytoplasmic immunohistochemical expression of CRH and UCN, from precancerous lesions to VSCC was observed. A similar increase was detected for Fas and FasL expression. Nuclear localization of UCN was demonstrated in both premalignant and VSCC lesions, with staining being significantly intensified in carcinomas, particularly in the less differentiated tumor areas or in the areas at invasive tumor front.

CONCLUSIONS

Stress response system and CRH family peptides seem to have a role in inflammation maintenance and progression of vulvar premalignant lesions to malignancy. It seems that stress peptides may locally modulate the stroma through Fas/FasL upregulation, possibly contributing to vulvar cancer development.

Possible Correlation between Urocortin 1 (Ucn1) and Immune Parameters in Patients with Endometriosis

The etiology of endometriosis (EMS) has not been clearly elucidated yet, and that is probably the reason why its diagnostic process is frequently long-lasting and inefficient. Nowadays, the non-invasive diagnostic methods of EMS are still being sought. Our study aimed to assess the serum and peritoneal fluid levels of urocortin 1 (Ucn1) in patients with EMS and healthy women. Moreover, considering the immune background of the disease, the association between Ucn1 and several immune parameters was studied in both groups. We found that the serum Ucn1 level was significantly upregulated in women with EMS compared to healthy patients. Moreover, higher serum Ucn1 levels tended to correspond with more advanced stages of the disease (p = 0.031). Receiver operating characteristic (ROC) analysis revealed that based on serum Ucn1 levels, it is possible to distinguish deep infiltrating endometriosis (DIE) from among other EMS types. Together, these results indicate Ucn1 as a possible promising biomarker of EMS: however, not in isolation, but rather to enhance the effectiveness of other diagnostic methods.

Urocortin stimulates ERK1/2 phosphorylation and proliferation but reduces ATP production of MCF7 breast cancer cells

Urocortins are members of the stress-related corticotropin-releasing factor family. Small amounts of them are present in the circulation and they are produced locally in various tissues of higher vertebrates. Aside from regulating circulation, or food uptake they also influence, via auto- and paracrine mechanisms, cell proliferation. In the present study we investigated in MCF7 human breast cancer cells the effect of urocortin onto mitogenic signaling via ERK1/2. Our results revealed that already 10 nM urocortin could stimulate the phosphorylation of these kinases and cell proliferation of MCF7 cells while ATP production was reduced when kept in the presence of the peptide up to two days. We examined the expression and contribution of the specific receptors of urocortin to the activation of ERK1/2 and to cell proliferation, the intracellular distribution of phosphorylated ERK1/2, and the involvement of additional proteins like PKA, PKB/Akt, MEK, p53, Rb and E2F-1 behind the observed phenomena.

Association between genetic variant rs2267716 of CRHR2 gene with colorectal cancer

Colorectal cancer (CRC) is the third most common cancer and one of the main causes of death around the world. Multiple lines of evidence have suggested the role of the corticotropin-releasing hormone (CRH) family in CRC induction, including the low expression of corticotropin-releasing hormone receptor 2 (CRHR2), which is an angiogenesis inhibitor and inflammatory modulator. Previous research suggests that CRHR2 expression in colonic intestinal cells can regulate migration, proliferation and apoptosis through the modulation of several pathways. The aim of this study was to analyze the association of the rs10250835, rs2267716 and rs2267717 variants of CRHR2 gene with CRC in the Mexican population in order to consider its predictive value in CRC. This cross-sectional study included a group of 187 unrelated patients with sporadic CRC and a control group of 191 healthy blood donors. DNA extraction from peripheral blood was carried out using the Miller method. Identification of the rs10250835 variant was performed using PCR-restriction fragment length polymorphism (RFLP) and the rs2267716 and rs2267717 variants using TaqMan allelic discrimination assay. The minor allele homozygous CC of the rs2267716 variant of CRHR2 showed significant difference between CRC and control group (p=0.025), as well as the GCA haplotype (p=0.007), corresponding to the rs10250835, rs2267716 and rs2267717 variants, respectively. Our results suggest that the rs2267716 variant and GCA haplotype of CRHR2 represent a risk factor for CRC development in Mexican patients.

Involvement of CRF2 signaling in enterocyte differentiation

AIM

To determine the role of corticotropin releasing factor receptor (CRF2) in epithelial permeability and enterocyte cell differentiation.

METHODS

For this purpose, we used rat Sprague Dawley and various colon carcinoma cell lines (SW620, HCT8R, HT-29 and Caco-2 cell lines). Expression of CRF2 protein was analyzed by fluorescent immunolabeling in normal rat colon and then by western blot in dissociated colonic epithelial cells and in the lysates of colon carcinoma cell lines or during the early differentiation of HT-29 cells (ten first days). To assess the impact of CRF2 signaling on colonic cell differentiation, HT-29 and Caco-2 cells were exposed to Urocortin 3 recombinant proteins (Ucn3, 100 nmol/L). In some experiments, cells were pre-exposed to the astressin 2b (A2b) a CRF2 antagonist in order to inhibit the action of Ucn3. Intestinal cell differentiation was first analyzed by functional assays: the trans-cellular permeability and the para-cellular permeability were determined by Dextran-FITC intake and measure of the transepithelial electrical resistance respectively. Morphological modifications associated to epithelial dysfunction were analyzed by confocal microscopy after fluorescent labeling of actin (phaloidin-TRITC) and intercellular adhesion proteins such as E-cadherin, p120ctn, occludin and ZO-1. The establishment of mature adherens junctions (AJ) was monitored by following the distribution of AJ proteins in lipid raft fractions, after separation of cell lysates on sucrose gradients. Finally, the mRNA and the protein expression levels of characteristic markers of intestinal epithelial cell (IEC) differentiation such as the transcriptional factor krüppel-like factor 4 (KLF4) or the dipeptidyl peptidase IV (DPPIV) were performed by RT-PCR and western blot respectively. The specific activities of DPPIV and alkaline phosphatase (AP) enzymes were determined by a colorimetric method.

RESULTS

CRF2 protein is preferentially expressed in undifferentiated epithelial cells from the crypts of colon and in human colon carcinoma cell lines. Furthermore, CRF2 expression is down regulated according to the kinetic of HT-29 cell differentiation. By performing functional assays, we found that Ucn3-induced CRF2 signaling alters both para- and trans-cellular permeability of differentiated HT-29 and Caco-2 cells. These effects are partly mediated by Ucn3-induced morphological changes associated with the disruption of mature AJ in HT-29 cells and tight junctions (TJ) in Caco-2 cells. Ucn3-mediated activation of CRF2 decreases mRNA and protein expression levels of KLF4 a transcription factor involved in IEC differentiation. This signaling is correlated to a down-regulation of key IEC markers such as DPPIV and AP, at both transcriptional and post-transcriptional levels.

CONCLUSION

Our findings suggest that CRF2 signaling could modulate IEC differentiation. These mechanisms could be relevant to the stress induced epithelial alterations found in inflammatory bowel diseases.

Urocortin suppresses endometrial cancer cell migration via CRFR2 and its system components are differentially modulated by estrogen

Urocortin (UCN1) peptide shares structural and functional homology with corticotropin‐releasing factor (CRF). UCN1 is significantly reduced in endometrial adenocarcinoma compared to healthy controls. However, there are no data which evaluate the effects of UCN1 in the endometrium, or how it is modulated. We used proliferation and transwell assays to determine the effect of UCN1 on the proliferation and migration of Ishikawa and HEC1A cells. We also determined the expression levels of UCN1 and its receptors produced by estrogen receptor agonists, and the effect of UCN1 on estrogen receptor expression, using quantitative polymerase chain reaction. UCN1 suppressed migration of endometrial cancer cells in vitro. This effect appears to be specific to CRF receptor 2 (CRFR2), as selective antagonism of CRFR2 but not CRFR1 completely eliminated suppression of migration. Activation of ERA reduced UCN1 expression, but only had a small effect on the expression of CRFR1. However, expression of CRFR2 was more notably reduced at both the mRNA and protein levels by activation of ERB. UCN1 in turn reduced both ERA and ERB expression, as assessed by real‐time quantitative PCR. We demonstrate that UCN1 significantly suppresses the migration of endometrial cancer cells but has no effect on their proliferation. Thus, loss of UCN1 in endometrial cancer may promote invasion and metastatic spread. There is a complex relationship between the UCN1 system and estrogen receptors, which may provide insights into endometrial carcinogenesis, a disease known to be driven by estrogen excess.

Role of urocortin in pregnancy: An update and future perspectives

The activities of corticotropin-releasing factor (CRF) and related peptides are mediated a number of receptors with seven transmembrane domains that are coupled to the Gs and Gq proteins. These receptors are known as CRF-Rs. In vitro studies have evidenced that urocortin (UCN) and CRF provoke an increase in the contractility of the uterus which is induced by endometrial prostaglandin F2a. Furthermore, through trophoblasts, it stimulates the secretion of adrenocorticotropic hormone (ACTH) and prostaglandin PGE2 and has a vasodilatory effect on the placenta. While it is well known that the placenta produces considerable quantities of CRF, several studies have, however, excluded that the placenta can generate significant quantities of UCN. In the short term, the human fetal adrenal gland produces more cortisol and dehydroepiandrosterone sulfate. The gestational tissues express UCN3 and UCN2 mRNA in cytotrophoblast and syncytiotrophoblast cells, while UCN2 is only to be found in the maternal and fetal vessels and amniotic cells. Nevertheless, gestational tissues express UCN2 and UCN3 differentially and do not stimulate placental ACTH secretion. In term pregnancies, maternal plasma levels of CRF and UCN are lower than at the beginning of pregnancy and are correlated to labor onset. Conversely, they do not decrease in post-term pregnancies. This evidence would seem to indicate that the fine-regulated expression of these neuropeptides is important in determining the duration of human gestation. In this scenario, low concentrations of UCN in the amniotic fluid at mid-term may be considered a sign of predisposition to preterm birth.

Immunolocalization of corticotropin-releasing hormone (CRH) and its receptors (CRHR1 and CRHR2) in human endometrial carcinoma: CRHR1 as a potent prognostic factor

Supplemental digital content is available in the text.

Objective

Corticotropin-releasing hormone (CRH), a major regulator of the stress response, regulates various biological functions through its interaction with CRH receptors 1 (CRHR1) and 2 (CRHR2). CRH, CRHR1, and CRHR2 have recently been reported in several types of carcinoma, but the significance of these proteins has remained largely unknown in human endometrial carcinoma.

Materials and Methods

A total of 87 endometrial carcinoma specimens were obtained from Japanese female patients who underwent surgical treatment, fixed in 10% formalin, and embedded in paraffin wax. Immunohistochemistry for CRH, CRHR1, and CRHR2 was performed, and clinical data were obtained from the medical records.

Results

Immunopositivity of CRH, CRHR1, and CRHR2 in the specimens was 26%, 15%, and 10%, respectively. Univariate analysis revealed that immunohistochemical CRH status was positively associated with CRHR1 and CRHR2 status and that CRHR1 status was significantly associated with the risk of recurrence and poorer clinical outcome, whereas CRHR2 status was marginally associated with better prognosis for overall survival. Multivariate analysis demonstrated CRHR1 status as an independent prognostic factor for both disease-free and overall survival.

Conclusions

These results suggest that intratumoral CRH-CRHR1 signaling plays an important role in the progression of endometrial carcinoma and that CRHR1 is a potent prognostic factor in patients with this disease.

Nuclear overexpression of urocortin discriminates primary brain tumors from reactive gliosis

The role of urocortin (UCN) is still ambiguous in human cancers. We tested the hypothesis that using UCN expression discriminates reactive gliosis from primary brain tumors (PBTs). Immunohistochemical analysis of UCN was performed in six reactive gliosis and 99 PBTs. The immunostain scores of UCN were calculated as the degree of intensity multiplied by the percentage of expressed tumor cells. Nuclear staining of UCN revealed weak intensity and small portion of positively stained cells in reactive gliosis. However, comparing with non-neoplastic tissues, higher immunostain scores of UCN were identified in each WHO grade of astrocytomas and meningiomas. Finally, neither WHO grade nor overall survival rate did not significantly correlate with UCN expression in astrocytomas and meningiomas. Our findings demonstrate for the first time that the application of UCN might be a novel biomarker for not only discriminating reactive gliosis from PBTs, but also deciding where the clear surgical margin was.

Secretion of urocortin I by human glioblastoma cell lines, possibly via the constitutive pathway

Corticotropin-releasing factor (CRF) and its family of peptides, i.e., urocortins (UCNs), play a critical role in systemic and peripheral stress-response systems and are widely expressed not only in normal tissues but also in various types of cancer cells. Given limited understanding of the mechanism of UCN I secretion, we investigated the UCN I secretory pathway in human neural stem cells (HNSCs) and in two glioblastoma cell lines, e.g., A172 and U-138 MG. Immunoreactivities for CRF receptors were detected in A172 glioblastoma cells, but not in HNSCs or U-138 glioblastoma cells, while UCN I immunoreactivity was detected in A172 and U-138 MG glioblastoma cell lines by both light field and electron microscopy. Interestingly, electron microscopy revealed UCN I immunoreactivtiy in vesicle-like structures in the plasma membrane of the glioblastoma cells. Tracking of a hybrid fluorescent protein containing a UCN I signal peptide expressed in A172 human glioblastoma cells revealed that fluorescence in secretory granules could be decreased by cycloheximide (100μg/ml), indicating that the forward transport of secretory granules containing fluorescent protein was not altered by the inhibition of protein synthesis by cycloheximide. Retrograde transport and the fusion of fluorescent granules in A172 human glioblastoma cells was induced by brefeldin A (10μg/ml), indicating that UCN I secretory granules may be transported via the constitutive pathway. Based on these results, it appears that UCN I is secreted from human glioblastoma cells by exocytosis through constitutive secretory granules, indicating that transcription of UCN I mRNA may be correlated to secretion of UCN I protein.

Corticotropin-releasing factor induces immune escape of cervical cancer cells by downregulation of NKG2D

Corticotropin-releasing factor (CRF), a coordinator of the body's responses to stress, is found in various cancer tissues and cell lines. However, the exact abilities of CRF to manipulate natural killer (NK) cells during immune response have not been studied. NKG2D is an activating receptor that is expressed on most NK and CD8+ T cells. MHC class I-related chain A (MICA) and UL16-binding protein (ULBP) 1, 2 and 3 are well-known ligands for NKG2D. In the present study, we reported our findings regarding the role of CRF in cervical cancer cell survival. Human cervical cancer cell line, HeLa cells, had significantly higher intracellular expression of UL16-binding protein 2 (ULBP2) following CRF treatment but had only slightly increased surface expression of ULBP2. Notably, MMPi (pan-metalloproteases inhibitor) blocked the release of ULBP2 molecules from the surface of HeLa cells. Furthermore, incubating NK cells with culture supernatants from CRF-treated HeLa cells, which contained soluble NKG2D ligand, reduced NK cell activity by decreasing surface expression of NKG2D. Collectively, downregulation of NKG2D by CRF-induced soluble NKG2D ligand provides a potential mechanism by which cervical cancer cells escape NKG2D-mediated attack under stress conditions.

Urocortin affects migration of hepatic cancer cell lines via differential regulation of cPLA2 and iPLA2

Urocortin (UCN) is a member of corticotrophin-releasing factor (CRF) family, which has been reported to play a role in many biological processes, including inflammation and cancer development. Growing evidence shows that PLA2 (phospholipase A2) enzymes also participate in inflammation and tumor development. The primary aim of the present study was to identify a novel signaling pathway of CRF receptor activation leading to migration of two kinds of hepatoma carcinoma cell lines, HepG2 and SMMC-7721, linking the stimulation of PLA2 expression by UCN to UCN-induced tumor cell migration. Pharmacological inhibitors and genetic approaches (such as stable transfection and siRNAs) were used in this study. Unlike HepG2 cells which express both CRF receptors themselves, SMMC-7721 cells which hardly express these two CRF receptors needed stable transfection with CRFR1 or CRFR2 to observe the effect of UCN. Two types of PLA2 enzymes, cPLA2 and iPLA2, were found to be regulated by UCN. Our data showed that UCN raised cPLA2 expression but lowered iPLA2 expression. Moreover, UCN was found to act on the certain region of iPLA2 promoter to reduce its transcription. UCN promoted tumor cell migration by up-regulating cPLA2 expression via CRFR1 whereas it suppressed tumor cell migration by down-regulating iPLA2 expression via CRFR2. These results indicate the dual roles for UCN in the hepatoma carcinoma cell migration, which involve the regulation of both cPLA2and iPLA2.

Expression of urocortin in pancreatic ductal adenocarcinoma and pancreatic intraepithelial neoplasia

Urocortin (UCN) is a 40-amino acid neuropeptide that regulates angiogenesis and inhibits cell proliferation. Our aim was to examine the relationship of UCN expression to the clinicopathological parameters of pancreatic ductal adenocarcinoma (PDAC) and histological grade of pancreatic intraepithelial neoplasia (PanIN). Tissue microarray was used to analyze UCN protein expression in 89 surgical specimens including 21 PanIN, 3 PDAC arising from PanIN, and 65 PDAC without PanIN. UCN immunoscores ranging from 0 to 12 were obtained by multiplying intensity (scored on a 3-point scale) by the percentage of stained cells (scored on a 4-point scale). Strong expression of UCN was detected in 5 specimens of non-neoplastic pancreatic ductal epithelia. UCN immunoscore was significantly higher in PanIN-1 than in PanIN-2 and PanIN-3 (p = 0.038) and significantly higher in well-differentiated PDAC or early American Joint Committee on Cancer (AJCC) stage PDAC than in poorly differentiated or advanced stage PDAC (p = 0.025, p = 0.018). Higher expression of UCN correlates with PDAC tumor grade and AJCC pathologic stage as well as PanIN grade. Immunohistochemical assessment of UCN may help clinicians predict tumor recurrence rate and help pathologists make a proper diagnosis.

Urocortin and corticotropin-releasing factor receptor 2 in human renal cell carcinoma: disruption of an endogenous inhibitor of angiogenesis and proliferation

Purpose

Urocortin (Ucn) exerts its actions through activation of two corticotropin-releasing factor receptors (CRFRs), CRFR1 and CRFR2. Involvement of Ucn/CRFR2 system in pathophysiological conditions such as the regulation of angiogenesis and inhibition of proliferation has been already reported. Suppression of neovascularization through reduction of vascular endothelial growth factor and inhibition of tumor cell cycling is modulated mainly through activation of CRFR2. To find out a possible involvement of Ucn/CRFR2 in kidney tumor, we examined the expression of Ucn and CRFR2 in normal and tumoral kidney specimens.

Methods

We applied reverse transcriptase PCR (n = 14), immunofluorescence (IF) on tissue microarrays (n = 25) and confocal microscopy to examine the mRNA expression and peptide/protein localization of Ucn and CRFR2 in normal kidney versus clear cell renal cell carcinoma, respectively.

Results

Ucn and CRFR2 mRNAs are expressed in normal and tumor specimens. In normal tissue, IF showed a cytoplasmic staining of Ucn mainly in proximal tubules, whereas a diffuse nuclear staining with diverse intensity was observed in tumoral tissues. CRFR2 was detected in proximal tubules and vasculature of normal specimens. Intriguingly, an almost complete loss of CRFR2 was observed in epithelial cells and microvessels within tumor tissues.

Conclusions

Here, and for the first time, we show the expression of Ucn and CRFR2 in human kidney and renal cell carcinoma. We propose that the nuclear translocation of Ucn along with the loss of CRFR2 in epithelial cells and microvasculature of tumoral specimens may be involved in the pathobiology of renal cell carcinoma.

Distinct distribution of corticotropin releasing factor receptors in human breast cancer

The hypothalamic neuropeptide corticotropin releasing factor (CRF) has been found in several types of human cancer, where its biological role is not clarified. In experimental models of breast cancer CRF has been shown to exert anti-proliferative and other actions. Aim of the present study was to describe the expression of the two types of CRF receptors CRF(1) and CRF(2) in human breast tumors. Receptor expression was studied in breast biopsies from patients diagnosed for primary breast adenocarcinoma, obtained from the tumor and the adjacent benign tissue. Gene expression levels were evaluated by real-time PCR following reverse transcription of total RNA extracts. CRF(1) transcripts were found in 23.1% of benign and in 23.1% of malignant biopsies. CRF(2(a)) was found in 22.2% of benign and 36.0% of malignant biopsies. Transcript levels of both receptors did not differ significantly between cancer and benign biopsies from the same tumor. No correlation was found between CRF receptor expression and patient histo/clinicopathological characteristics. Histological mapping using immunohistochemistry revealed positive CRF(1) immunostaining in the cancerous implants and breast ducts, whereas CRF(2) immunoreactivity was localized mainly in the perineural invasions. In conclusion, both CRF receptors were found in breast cancer and the respective benign adjacent tissue. The two CRF receptor proteins presented distinct distribution and subcellular localization, pointing into differing biological roles. CRF receptors could serve as targets of endogenous ligands expressed in the tumor microenvironment, regulating cancer growth.

The corticotropin releasing factor system in cancer: expression and pathophysiological implications

Malignant tumors express multiple factors that have some role in the regulating networks supporting their ectopic growth. Recently, increased interest has been developing in the expression and biological role of the neuropeptides and receptors of the corticotropin releasing factor (CRF) system, the principal neuroendocrine mediator of the stress response, especially in the light of several R&D programs for small molecule antagonists that could present some anticancer therapeutic benefit. In the present article, we review the literature suggesting that the CRF system could be involved in the regulation of human cancer development. Potential implication in growth, metastasis, angiogenesis, or immune parameters via activation of locally expressed receptors could be clinically exploited by presenting targets of new therapeutic approaches.

Activation of corticotropin-releasing factor receptor 2 inhibits the growth of human small cell lung carcinoma cells

Previously, we found the activation of corticotropin-releasing factor receptor 2 (CRFR2) could inhibit tumor growth via an anti-angiogenic pathway, implying CRFR2 may be a tumor therapeutic target. Here, CRFR2 expression in human neuroendocrine small cell lung carcinoma (SCLC) tissues and cell lines NCI-H446 and NCI-H1688 were detected. Meanwhile, UCNs could directly inhibit the proliferation and promote the apoptosis of SCLC cells via CRFR2. It was also shown that the activation of CRFR2 could inhibit p38 and Akt phosphorylation to suppress the secretion of VEGF in SCLC cells. These observations implied CRFR2 might be a therapeutic target in human SCLC.

An intronic polymorphism in the corticotropin-releasing hormone receptor 2 gene increases susceptibility to HBV-related hepatocellular carcinoma in Chinese population

Corticotropin-releasing hormone receptor 2 (CRHR2) plays a role in both the central nervous system (CNS) and the peripheral nervous system. CRHR2 together with its ligands, urocortins (Ucns) and corticotropin-releasing hormone (CRH), functions as a mediator of inflammatory response and inhibitor of angiogenesis. Recently, it has been reported to be expressed in many human cancers. An association between rs2267716 polymorphism in the CRHR2 gene and susceptibility to hepatocellular carcinoma (HCC) was found in patients with chronic hepatitis C virus (HCV) infection. In the present study we analyzed, using a polymerase chain reaction-ligation detection reaction (PCR-LDR), the rs2267716 polymorphism in 364 hepatitis B virus (HBV)-related HCC patients, 196 non-HCC patients with HBV infection, and 404 healthy controls. The aim was to detect the possible association of this single-nucleotide polymorphism (SNP) with susceptibility to HBV-related HCC. Significant differences of rs2267716 allele were detected between HBV-related HCC patients and healthy controls (OR = 1.55, 95% CI 1.13-2.15, P = 0.007) or non-HCC patients with HBV infection (OR = 1.61, 95% CI 1.13-2.31, P = 0.009). These results suggest that the rs2267716 polymorphism in the CRHR2 gene might influence the risk of developing HCC in patients with HBV infection in Chinese population.

Expression and subcellular localization of CRH and its receptors in human endometrial cancer

CRH and its receptors are expressed in human normal endometrial cells, where they are associated to anti-proliferative progesterone-like activity. We aimed to investigate CRH, CRH-R1 and CRH-R2 expression and intracellular localization in human endometrial cancers and their relationships with tumor biological parameters. Surgical specimens were obtained from 51 untreated endometrial cancer patients and immunohistochemistry for CRH, CRH receptors, ER, PR and Ki-67 was performed. We found a diffuse cytoplasmic staining in 100%, 92 % and 60.7 % of tumor specimens for CRH, CRH-R1 and CRH-R2, respectively. At variance with tumor tissues, the surrounding normal endometrial glands exhibit a typical paranuclear/apical pattern for CRH and stained for CRH-R2 at the nuclear level, whereas CRH-R1 staining was similar to that observed in tumor area. Positive correlations were found between CRH-R1 and PR expression, as well as between CRH-R2 cytoplasmic pattern and more advanced FIGO stage disease, respectively.

Urocortin's inhibition of tumor growth and angiogenesis in hepatocellular carcinoma via corticotrophin-releasing factor receptor 2

Urocortin (UCN) functions via corticotrophin-releasing factor receptors (CRFRs), CRFR1 & 2. CRFR2 is reported to be a tonic suppressor of vascularization, implying its role in tumor angiogenesis. Here, it was found that UCN inhibited the growth of hepatocellular carcinoma (HCC) and reduced tumor microvessel density in nude mice. Hepatoma cells didn't express CRFRs whereas vessels expressed CRFRs, mainly CRFR2. In vitro three-dimensional culture assay showed UCN inhibited angiogenesis, this effect was abolished by CRFR2 antagonist, anti-sauvagine-30, demonstrating involvement of CRFR2. Furthermore, UCN inhibited the proliferation and promoted the apoptosis of endothelial cells and down-regulated VEGF expression in vivo via CRFR2.

Evaluation of Endometrial Urocortin Secretion for Prediction of Pregnancy after Intrauterine Insemination

Background: Urocortin is a neuropeptide produced by the human endometrium and has biological effects putatively important for promoting blastocyst implantation. We measured urocortin concentrations in samples of endometrial wash fluid collected from women with unexplained infertility who underwent intrauterine insemination (IUI).

Methods: Patients 28–42 years of age (n = 71) were consecutively enrolled after a complete clinical evaluation. Endometrial wash fluid was retrieved before IUI, at the time of ultrasound evaluation of endometrial thickness. Urocortin concentrations were assayed with a specific ELISA.

Results: After IUI, 28 patients (39%) became pregnant. Urocortin concentrations were significantly higher in women who became pregnant than in those who did not (0.38 μg/L vs 0.13 μg/L, P <0.0001). At a cutoff of 0.321 μg/L, urocortin results were positive in 61% [95% confidence interval (CI), 41%–78%] of women who had successful implantation and negative in 98% (95% CI, 88%–99.6%) of those who did not. The pregnancy rate for women with urocortin concentrations >0.32 μg/L was 94%, which differed significantly (P <0.05) from the overall pregnancy rate of 39% in the study population.

Conclusions: Urocortin is measurable in endometrial wash fluid, and its concentrations before IUI are higher in women who subsequently achieve pregnancy. These data suggest that the probability of having a successful pregnancy-producing IUI may be better estimated by measuring urocortin in endometrial wash fluid.

Plasma urocortin levels in the diagnosis of ovarian endometriosis

OBJECTIVE

Urocortin is a neuropeptide, member of the corticotropin-releasing hormone family, that is produced by the human endometrium. Ovarian endometrioma is a prevalent gynecologic disorder still lacking specific serum markers. In the present study we measured systemic levels of urocortin to assess the diagnostic performance of its determination in distinguishing endometriomas from other benign ovarian cysts.

METHODS

Plasma urocortin was measured by radioimmunoassay in women with ovarian endometrioma (n=40) and in women with benign, nonendometriotic ovarian cysts (n=40). The diagnostic accuracy of urocortin measurement was evaluated by receiver operating characteristic curve and compared with the standard marker, CA 125. To support the local origin of the peptide, we also evaluated its localization in endometriomas by immunohistochemistry and its concentrations in cyst fluid and peritoneal fluid of 12 women with endometrioma.

RESULTS

Plasma urocortin levels were twice as high in women with endometrioma (median 49 pg/mL, interquartile range 41-63 pg/mL) than in the control group (19 [15-23] pg/mL, P<.001) and significantly higher in the cystic content of endometriomas than in the peritoneal fluid and plasma (P<.05). The peptide was immunolocalized in endometrioma glands and stromal capillary vessels. Elevated plasma urocortin levels detected 88% of the cases of endometrioma with 90% specificity, whereas CA 125 detected only 65% of the cases with the same specificity.

CONCLUSION

Plasma urocortin is increased in women with endometriomas, and its measurement may be useful for the differential diagnosis of endometrioma compared with other benign ovarian cysts.

LEVEL OF EVIDENCE

II.

Corticotropin-releasing factor family and its receptors: tumor therapeutic targets?

Urocortin (UCN) and corticotropin-releasing factor (CRF) are members of CRF family. Though CRF is mainly distributed in central nervous system (CNS), UCN has been reported to play biologically diverse roles in several systems such as cardiovascular, respiratory, digestive, reproductive, stress, immunologic system, etc. UCN and CRF bind to two known receptors, CRFR1 and CRFR2, to function. Both CRF receptors are distributed in CNS and periphery tissues, and their expression in cancer tissues has been reported. Now there are many documents indicating UCN/CRF play an important role in the regulation of carcinogenesis. There is also evidence indicating UCN/CRF have anticancer effects via CRFRs. This paper will review the effects of CRF family in cancers.