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

mRNA expression of CRF family members in urothelial bladder cancer

The corticotropin-releasing factor (CRF) gene family includes the three urocortins (UCN1, 2 and 3) and the two receptors (CRFR1 and 2), which play a significant role in the physiology of various organs. The expression of the CRF family of genes and its receptors are shown to participate in the pathogenesis of inflammation and even tumorigenesis. However, data regarding the human urinary tract, especially the bladder, are scarce. To the best of our knowledge, no studies are currently available on the CRF system and bladder cancer. The primary goal of the present study was to investigate the mRNA expression of the CRF family members in bladder cancer. The secondary aim was to analyze the differences with the expression of the same mRNAs in normal bladders. From August 2018 to July 2021, 43 recruited patients were divided into three groups. Group A included healthy patients, group B included patients with bladder cancer and group C included patients with a history of cancer from whom samples were taken from the normal bladder mucosa. Detection of mRNA of the CRF family of genes was performed using reverse transcription-quantitative PCR. The mRNA of the three urocortins, CRF and the two receptors were predominantly expressed in all three groups of patients. Statistical analysis using the Kruskal-Wallis test showed that UCN1 was downregulated in patients with bladder cancer and those with possible cancer compared with the healthy group (mean rank group A=24.3 vs. mean rank group B=12.58; P=0.006) and (mean rank group A=24.3 vs. mean rank group C=8.88; P=0.001). The present experiments showed that mRNA of the CRF family of genes was amplified in normal and cancer bladder tissues. Downregulation of the UCN1 gene may be associated with bladder cancer, contributing to the prognosis, diagnosis or therapy of urothelial malignancies.

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.

Identification of Hypoxia-Immune-Related Gene Signatures and Construction of a Prognostic Model in Kidney Renal Clear Cell Carcinoma

Introduction: Kidney renal clear cell carcinoma (KIRC), a kind of malignant disease, is a severe threat to public health. Tracking the information of tumor progression and conducting a related dynamic prognosis model are necessary for KIRC. It is crucial to identify hypoxia-immune-related genes and construct a prognostic model due to immune interaction and the influence of hypoxia in the prognosis of patients with KIRC. Methods: The hypoxia and immune status of KIRC patients were identified by utilizing t-SNE and ImmuCellAI for gene expression data. COX and Lasso regression were used to identify some hypoxia-immune-related signature genes and further construct a prognostic risk model based on these genes. Internal and external validations were also conducted to construct a prognostic model. Finally, some potentially effective drugs were screened by the CMap dataset. Results: We found that high-hypoxia and low-immune status tend to induce poor overall survival (OS). Six genes, including PLAUR, UCN, PABPC1L, SLC16A12, NFE2L3, and KCNAB1, were identified and involved in our hypoxia-immune-related prognostic risk model. Internal verification showed that the area under the curve (AUC) for the constructed models for 1-, 3-, 4-, and 5-year OS were 0.768, 0.754, 0.775, and 0.792, respectively. For the external verification, the AUC for 1-, 3-, 4-, and 5-year OS were 0.768, 0.739, 0.763, and 0.643 respectively. Furthermore, the decision curve analysis findings demonstrated excellent clinical effectiveness. Finally, we found that four drugs (including vorinostat, fludroxycortide, oxolinic acid, and flutamide) might be effective and efficient in alleviating or reversing the status of severe hypoxia and poor infiltration of immune cells. Conclusion: Our constructed prognostic model, based on hypoxia-immune-related genes, has excellent effectiveness and clinical application value. Moreover, some small-molecule drugs are screened to alleviate severe hypoxia and poor infiltration of immune cells.

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.

Current updates and future perspectives on the management of renal cell carcinoma

Renal cell carcinoma (RCC) refers to renal-epithelial cancer, which represents over 90% of kidney cancer and is a cause for cancer related deaths in the world. Studies suggested somatic VHL mutations to be the cause for the occurrence of cancer, but with the time, more latest genomic and biological studies have detected variation in epigenetic regulatory genes and showed significant heterogeneity of the intratumor that may lead to strategies of diagnostic, predictive, and therapeutic importance. Immune dysfunction is responsible for almost all types of renal cancer, and angiogenesis and immunosuppression function together in the tumor microenvironment of renal cell carcinoma (RCC). Over the past few years, advancement in the management of the RCC has finally revolutionized with the arrival of the entrapped immune inhibitors which particularly concentrated on the receptor (programmed cell death-1) and focus on the new generation receptor i.e. TKRI (tyrosine-kinase receptor inhibitors). The present review deals with the comprehensive review of RCC and emphasizes on its types, pathogenesis and advancement in these diseases. This review also overviews the role of innate and adaptive immune response-related mechanism, the function of cancer stem cell in this diseases, therapeutic targeted drugs and hormonal signaling pathways as an emerging strategy in the management of the renal cancer.

Type 2β Corticotrophin Releasing Factor Receptor Forms a Heteromeric Complex With Dopamine D1 Receptor in Living Cells

Corticotrophin releasing factor (CRF) and its related peptides differentially bind to CRF receptors to modulate stress-related behaviors. CRF receptors comprise two G-protein coupled receptors (GPCR), type-1 CRF receptors (CRF1), and type-2 CRF receptors (CRF2). CRF2 encompasses three spliced variants in humans, alpha (CRF2α), beta (CRF2β), and gamma (CRF2γ), which differ in their N-terminal extracellular domains and expression patterns. Previously, we showed that CRF2α form a heteromeric protein complex with dopamine D1 receptors (D1R), leading to changes in the signaling of D1R. Based on the high sequence identity between CRF2α and CRF2β, we hypothesized that CRF2β also heteromerize with D1R. To test the hypothesis, we compared the expression and localization of both CRF2 isoforms and whether CRF2β form stable protein complexes with D1R in HEK293 and ATR75 cell lines. We observed that the immunoreactivity for CRF2β was similar to that of CRF2α in the endoplasmic compartment but significantly higher in the Golgi compartment. Immunoprecipitation analysis showed that CRF2β forms a heteromeric protein complex with D1R. Furthermore, the protein complex formed by CRF2β and D1R was stable enough to change the sub-cellular localization of CRF2β when it was co-expressed with a construct of D1R bearing a nuclear localization signal. Immunofluorescence in A7R5 cells, which endogenously express CRF2β and D1R, shows significant colocalization of CRF2β with D1R. In conclusion, our results show that CRF2β forms a stable heteromeric protein complex with D1R, a potential new therapeutic target in tissues where both receptors are co-expressed, such as the septum in the brain, and heart, kidney, and skeletal muscle in the periphery.

Hypermethylation of Corticotropin Releasing Hormone Receptor-2 Gene in Ulcerative Colitis Associated Colorectal Cancer

BACKGROUND/AIM

The difficulty of early diagnosis of colitis associated colorectal cancer (CACRC) due to colonic mucosal changes in long-standing ulcerative colitis (UC) patients is often experienced in daily clinical practice. Noninvasive objective monitoring for cancer development is advantageous for optimizing treatment strategies in UC patients. We aimed to examine the epigenetic alterations occurring in CACRC, focusing on DNA hypermethylation of CpG islands.

MATERIALS AND METHODS

The level of DNA methylation in CpG cites was compared between CACRC and the counterpart non-tumorous mucosa using Infinium HumanMethylation 450K BeadChip.

RESULTS

Our subjects included 3 males and 3 females (median age, 49.5 years). The 450K CpG site DNA methylation microarray revealed that the difference in β value (level of hypermethylation) was the highest for corcicotropin releasing hormone receptor 2 (CRHR2) between CACRC and counterpart non-tumorous mucosa.

CONCLUSION

Detection of hypermethylation of CRHR2 may be promising for cancer screening in UC patients.

Cancer-Specific Loss of Urocortin 3 in Human Renal Cancer

INTRODUCTION

The corticotropin-releasing hormone (CRH) system, its receptors corticotropin-releasing hormone receptor 1 (CRHR1) and 2 (CRHR2), and its corresponding binding protein corticotropin-releasing hormone-binding protein (CRHBP) as well as the urocortin proteins-structural homologues to CRH, which are included in this peptide family-have become interesting oncological targets recently. Carcinogenesis of various human tumors has been reported with an altered presence of members of this system. The aim of the present study was to examine the role of urocortin 3 (UCN3) in renal cell carcinoma (RCC).

METHODS

Therefore, tumoral tissues of 106 patients with RCC and available corresponding normal tissues were analyzed using qPCR for quantitative mRNA expression analysis. Tissue localization and protein signals of UCN3 in normal and tumoral renal specimens were evaluated using western blot and immunohistochemistry. In addition, correlation studies of UCN3 mRNA expression with clinicopathological parameters of patients with RCC and different histological subtypes were evaluated.

RESULTS

UCN3 mRNA was significantly downregulated in nearly all tumoral tissues (p = 7.92 × 10^-13). The same effect was observed at protein level using immunohistochemistry. Level of UCN3 mRNA expression was not directly correlated with clinicopathological parameters.

CONCLUSION

We report for the first time the significant downregulation of UCN3 in RCC. These results demonstrate a possible involvement of the CRH system and its significance in carcinogenesis of RCC.

Tumor Specific Epigenetic Silencing of Corticotropin Releasing Hormone -Binding Protein in Renal Cell Carcinoma: Association of Hypermethylation and Metastasis

The relevance of Corticotropin Releasing Hormone (CRH)-system in human malignancies is a question of growing interest. Here we investigated hypermethylation and epigenetic silencing of the CRH-Binding Protein (CRHBP) gene in clear cell renal cell cancer (ccRCC). Relative methylation of the CRHBP CpG island (CGI) was determined in 17 tumor cell lines as well as 86 ccRCC samples and 66 paired normal tissues using pyrosequencing and quantitative methylation specific PCR of bisulfite converted DNA. Results were statistically compared with relative mRNA expression levels of CRHBP and clinicopathological parameters of patients. Re-expression of CRHBP following 5-aza-2´-deoxycytidine treatment was investigated by quantitative mRNA expression analysis. Real-time impedance analysis was applied for analysis of invasiveness of renal tumor cells following si-RNA knockdown of CRHBP expression or ectopic expression of CRHBP. We found the CRHBP CGI to be frequently methylated in tumor cell lines of renal, prostatic, and bladder cancer. Comparison of methylation in normal and paired renal cancer tissue specimens revealed hypermethylation of the CRHBP CGI in tumors (p<1*10⁻¹²). DNA methylation and decreased mRNA expression were correlated (R = 0.83, p<1*10⁻¹²). Tumor cell lines showed 5-aza-2´-deoxycytidine dependent reduction of methylation and re-expression of CRHBP was associated with altered cellular invasiveness of renal cancer cells in real-time impedance invasion assays. Hypermethylation and inverse relationship with mRNA expression were validated in silico using the TCGA network data. We describe for the first time tumor specific epigenetic silencing of CRHBP and statistical association with aggressive tumors thus suggesting the CRH system to contribute to the development of kidney cancer.

Corticotropin Releasing Hormone and Urocortin 3 Stimulate Vascular Endothelial Growth Factor Expression through the cAMP/CREB Pathway

Colonic epithelium is the first line of defense against various pathological offenses in the gut. Previous studies have shown that the peptides of the corticotropin-releasing hormone (CRH) family modulate vascular endothelial growth factor (VEGF)-A production in other cells. Here we sought to investigate whether CRH and urocortin (Ucn) 3 regulate VEGF-A secretion in colonocytes through CRH receptors and to elucidate the underlying mechanism of action. CRH and Ucn 3 significantly increased the expression levels of VEGF-A mRNA and protein through CRH receptor 1 and 2, respectively, in human colonic epithelial cells and primary mouse intestinal epithelial cells. Underlying mechanisms involve activation of adenylyl cyclase with subsequent increase of intracellular cAMP level and increased DNA binding activity of transcription factor CREB on VEGF-A promoter region. Finally, genetic deficiency of CREB decreased intestinal inflammation and VEGF-A expression in a dextran sodium sulfate-induced colitis model. These results show that activation of CRH receptors by CRH ligands stimulates VEGF-A expression in intestinal epithelial cells through the cAMP/CREB pathway. Since VEGF-A boosts inflammatory responses through angiogenesis, these data suggest that CREB may be a key effector of CRH and Ucn 3-dependent inflammatory angiogenesis.

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.

Evaluation of the effect of natural peptide 'Urocortin' on corticotrophin releasing factor (CRF) receptor expression in ND7/23 cells

CRF receptors are involved in the stress management of the cells and are believed to have a cytoprotective role in the body. CRF receptors have been reported to be potential drug targets for the treatment of neurodegenerative disorders. The cell line used in the study is ND7/23 (mouse neuroblastoma and rat dorsal root ganglion neuron hybridoma). The aim of the study was to confirm the expression of CRF receptors in ND7/23 cells and to determine if urocortin (Ucn) can enhance the expression of CRF receptors. ND7/23 cells were cultured in RPMI 1640 media and cells grown after the second passage were used for the experiments. RNA was extracted from the cells and amplified by RT-PCR to confirm the presence of CRF receptors. The cells were then subjected to oxidative stress by hydrogen peroxide (0.00375%) and divided into two groups i.e. control and Ucn (10-8 μM) treated. Later RNA was extracted from both group of cells and PCR was performed. Finally, densitometry analysis was conducted on the agarose gel to determine the quantity of PCR product formed. PCR experiment confirmed the expression of both CRF-R1 and CRF-R2 in the cell line, but CRF-R1 was found to be expressed more strongly. Densitometry analysis of the PCR product and calculation of the relative expression of CRF receptors indicated a higher level of expression of CRF receptors in samples treated with Ucn as compared to those that were kept untreated. The results indicate that Ucn may be useful for the management of neuro-degenerative disorders and further studies may be carried out to establish its use as a therapeutic agent.

Multi-facets of Corticotropin-releasing Factor in Modulating Inflammation and Angiogenesis

The family of corticotropin-releasing factor (CRF) composed of 4 ligands including CRF, urocortin (Ucn) 1, Ucn2, and Ucn3 is expressed both in the central nervous system and the periphery including the gastrointestinal tract. Two different forms of G protein coupled receptors, CRF₁ and CRF₂, differentially recognize CRF family members, mediating various biological functions. A large body of evidence suggests that the CRF family plays an important role in regulating inflammation and angiogenesis. Of particular interest is a contrasting role of the CRF family during inflammatory processes. The CRF family can exert both pro-and anti-inflammatory functions depending on the type of receptors, the tissues, and the disease phases. In addition, there has been a growing interest in a possible role of the CRF family in angiogenesis. Regulation of angiogenesis by the CRF family has been shown to modulate endogenous blood vessel formation, inflammatory neovascularization and cardiovascular function. This review outlines the effect of the CRF family and its receptors on 2 major biological events: inflammation and angiogenesis, and provides a possibility of their application for the treatment of inflammatory vascular diseases.

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 Hormone and Its Biological Diversity toward Angiogenesis

Angiogenesis is the formation of new blood vessels from existing ones and an underlying cause of numerous human diseases, including cancer and inflammation. A large body of evidence indicates that angiogenic inhibitors have therapeutic potential in the treatment of vascular diseases. However, detrimental side effects and low efficacy hinder their use in clinical practice. Members of the corticotropin-releasing hormone (CRH) family, which comprises CRH, urocortin I-III, and CRH receptors (CRHR) 1 and 2, are broadly expressed in the brain and peripheral tissues, including the intestine and cardiovascular system. The CRH family regulates stress-related responses through the hypothalamic-pituitary-adrenal axis. Therapeutic agents that target CRH family members offer a new approach to the treatment of various gastrointestinal disorders, including irritable bowel syndrome (IBS), inflammatory bowel disease (IBD), and colorectal cancer. Since the discovery that CRHR 2 has anti-angiogenic activity during postnatal development in mice, studies have focused on the role of the CRH system in the modulation of blood vessel formation and cardiovascular function. This review will outline the basic biological functions of the CRH family members and the implications for the development of novel anti-angiogenic therapies.

Interactions of Enhanced Urocortin 2 and Mineralocorticoid Receptor Antagonism in Experimental Heart Failure

Background—

Mineralocorticoid receptor antagonists (MRAs) have become established therapy in heart failure (HF). Urocortin 2 (Ucn2) is a novel peptide with potential in the treatment of this disease. The present study investigated the interactions of acute administration of Ucn2 and an MRA in experimental HF.

Methods and Results—

Ucn2 and an MRA (canrenoic acid [CA]) were infused for 4 hours, both singly and together, in 8 sheeps with pacing-induced HF. Ucn2, when administered as an adjunct to CA, further improved hemodynamic indices relative to that achieved by CA alone, producing additional increases in cardiac output and decreases in left atrial pressure and peripheral resistance but without eliciting a supplementary reduction in arterial pressure. Ucn2 cotreatment reversed CA-induced rises in circulating aldosterone levels, and also significantly reduced plasma renin activity, angiotensin II, and vasopressin concentrations. Although both CA and Ucn2 infusion produced a diuresis and natriuresis, responses with Ucn2 and Ucn+CA were 2- to 3-fold greater than that elicited by separate CA. Ucn2 cotherapy additionally increased urine potassium and creatinine excretion. In contrast to the rise in plasma potassium induced by CA, Ucn2 cotreatment reduced potassium concentrations.

Conclusions—

Ucn2 cotreatment with an MRA in HF further improved hemodynamics relative to that achieved by CA alone, while also reducing plasma renin activity, angiotensin II, aldosterone and vasopressin levels, and enhancing renal function. Importantly, Ucn2 prevented CA-induced rises in plasma potassium. These data demonstrate a favorable profile of effects with short-term adjunct Ucn2 therapy and an MRA in HF.

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.

Reduced mRNA expression level of corticotropin-releasing hormone-binding protein is associated with aggressive human kidney cancer

Background

Significance of Urocortin (Ucn or UcnI), Ucn2, Ucn3 and their receptors, Corticotropin Releasing Factor Receptor 1 and 2 (CRFR1 and CRFR2), and the binding protein, Corticotropin-Releasing Hormone-Binding Protein (CRHBP) in oncology is growing rapidly. The objective of our study was to assess the expression of the CRHBP mRNA and protein in renal cancer.

Methods

Tumoral tissues of 78 patients with clear cell renal cell cancer and their corresponding normal tissues were analyzed using quantitative mRNA expression analysis for detection of mRNA expression level. Protein expression and tissue localization of CRHBP protein in renal specimens was evaluated using western blotting, immunohistochemistry and double immunofluorescence, respectively.

Results

We found an approx. 33 fold decrease of average CRHBP mRNA level in tumoral tissues compared to paired normal tissues (p<0.001). Diminished CRHBP mRNA expression was positively correlated with advanced, metastasized and higher stage of disease (p<0.001, p=0.026, p=0.028 respectively). CRHBP protein was detected in glomeruli and proximal tubules of normal kidney while none or weak immunopositivity was found in cc-RCC (p<0.001).

Conclusions

The expression analysis of CRHBP shows that cc-RCC is characterized by a significant loss of CRHBP mRNA expression that furthermore is associated with a more aggressive state of tumors. Depletion of CRHBP proteins also indicate that the protein as part of the UCN system may be involved in renal carcinogenesis.

The corticotropin releasing factor system in the kidney: perspectives for novel therapeutic intervention in nephrology

The adaptation to endogenous and exogenous stress stimuli is crucial for survival but also for the onset of various diseases in humans. Corticotropin releasing factor (CRF) system is the major regulator of stress response and homeostasis. The members of this family of peptides extend their actions also outside CNS to the periphery where they may affect various body systems independently, acting via vagal and/or autocrine/paracrine pathways. In search for peripheral targets, kidney has rarely been studied separately, regarding expression and action of CRF and CRF-related peptides. We reviewed the existing literature concerning expression and action of the CRF system in normal and pathological renal tissue and explored possible clinical implications in nephrology. CRF system components are expressed in the kidney of experimental animals and in humans. The intrarenal distribution is reported to be equally extensive, suggesting a physiological or pathophysiological role in renal function and in the occurrence of renal disease. Urocortins have given multiple interesting observations in experimental models of renal disease and clinical studies, showing robust effects in renal regulation mechanisms. We summarize the relevant data and put them in context, proposing applications with clinical significance in the field of hypertension, diabetic nephropathy, chronic kidney disease, cardiorenal syndrome, and peritoneal dialysis.

The impact of stress on tumor growth: peripheral CRF mediates tumor-promoting effects of stress

Introduction

Stress has been shown to be a tumor promoting factor. Both clinical and laboratory studies have shown that chronic stress is associated with tumor growth in several types of cancer. Corticotropin Releasing Factor (CRF) is the major hypothalamic mediator of stress, but is also expressed in peripheral tissues. Earlier studies have shown that peripheral CRF affects breast cancer cell proliferation and motility. The aim of the present study was to assess the significance of peripheral CRF on tumor growth as a mediator of the response to stress in vivo.

Methods

For this purpose we used the 4T1 breast cancer cell line in cell culture and in vivo. Cells were treated with CRF in culture and gene specific arrays were performed to identify genes directly affected by CRF and involved in breast cancer cell growth. To assess the impact of peripheral CRF as a stress mediator in tumor growth, Balb/c mice were orthotopically injected with 4T1 cells in the mammary fat pad to induce breast tumors. Mice were subjected to repetitive immobilization stress as a model of chronic stress. To inhibit the action of CRF, the CRF antagonist antalarmin was injected intraperitoneally. Breast tissue samples were histologically analyzed and assessed for neoangiogenesis.

Results

Array analysis revealed among other genes that CRF induced the expression of SMAD2 and β-catenin, genes involved in breast cancer cell proliferation and cytoskeletal changes associated with metastasis. Cell transfection and luciferase assays confirmed the role of CRF in WNT- β-catenin signaling. CRF induced 4T1 cell proliferation and augmented the TGF-β action on proliferation confirming its impact on TGFβ/SMAD2 signaling. In addition, CRF promoted actin reorganization and cell migration, suggesting a direct tumor-promoting action. Chronic stress augmented tumor growth in 4T1 breast tumor bearing mice and peripheral administration of the CRF antagonist antalarmin suppressed this effect. Moreover, antalarmin suppressed neoangiogenesis in 4T1 tumors in vivo.

Conclusion

This is the first report demonstrating that peripheral CRF, at least in part, mediates the tumor-promoting effects of stress and implicates CRF in SMAD2 and β-catenin expression.

Corticotropin-releasing hormone family of peptides regulates intestinal angiogenesis

BACKGROUND & AIMS

The corticotrophin-releasing hormone (CRH) family of peptides modulates intestinal inflammation and the CRH receptor 2 (CRHR2) suppresses postnatal angiogenesis in mice. We investigated the functions of CRHR1 and CRHR2 signaling during intestinal inflammation and angiogenesis.

METHODS

The activities of CRHR1 and CRHR2 were disrupted by genetic deletion in mice or with selective antagonists. A combination of in vivo, ex vivo, and in vitro measures of angiogenesis were used to determine their activity. CRHR1(-/-) mice and CRHR2(-/-) mice with dextran sodium sulfate-induced colitis were analyzed in comparison with wild-type littermates (controls).

RESULTS

Colitis was significantly reduced in mice in which CRHR1 activity was disrupted by genetic deletion or with an antagonist, determined by analyses of survival rate, weight loss, histological scores, and cytokine production. Inflammation was exacerbated in mice in which CRHR2 activity was inhibited by genetic deletion or with an antagonist, compared with controls. The inflamed intestines of CRHR1(-/-) mice had reduced microvascular density and expression of vascular endothelial growth factor (VEGF)-A, whereas the intestines of CRHR2(-/-) mice had increased angiogenesis and VEGF-A levels. An antagonist of VEGFR2 activity alleviated colitis in CRHR2(-/-) mice. Ex vivo aortic vessel outgrowth was reduced when CRHR1 was deficient but increased when CRHR2 was deficient. The CRHR1 preferred agonist CRH stimulated tube formation, proliferation, and migration of cultured intestinal microvascular endothelial cells by phosphorylating Akt, whereas the specific CRHR2 agonist Urocortin III had opposite effects.

CONCLUSION

CRHR1 promotes intestinal inflammation, as well as endogenous and inflammatory angiogenesis whereas CRHR2 inhibits these activities.

Differentiation dependent expression of urocortin's mRNA and peptide in human osteoprogenitor cells: influence of BMP-2, TGF-beta-1 and dexamethasone

Urocortin-1 (UCN) a corticotropin releasing-factor (CRF) related peptide, has been found to be expressed in many different tissues like the central nervous system, the cardiovascular system, adipose tissue, and skeletal muscle. The effects of UCN are mediated via stimulation of CRF-receptors 1 and 2 (CRFR1 and 2, CRFR’s) with a high affinity for CRFR2. It has been shown that the CRF-related peptides and CRFR’s are involved in the regulation of stress-related endocrine, autonomic and behavioural responses. Using immunocytochemistry, immunohistochemistry and RT–PCR, we now can show the differentiation dependent expression of UCN mRNA and peptide in human mesenchymal progenitor cells (MSCs) directed to the osteoblastic phenotype for the first time. UCN expression was down regulated by TGF-beta and BMP-2 in the early proliferation phase of osteoblast development, whereas dexamethasone (dex) minimally induced UCN gene expression during matrix maturation after 24 h stimulation. Stimulation of MSCs for 28 days with ascorbate/beta-glycerophosphate (asc/bGp) induced UCN gene expression at day 14. This effect was prevented when using 1,25-vitamin D3 or dex in addition. There was no obvious correlation to osteocalcin (OCN) gene expression in these experiments. In MSCs from patients with metabolic bone disease (n = 9) UCN gene expression was significantly higher compared to MSCs from normal controls (n = 6). Human MSCs did not express any of the CRFR’s during differentiation to osteoblasts. Our results indicate that UCN is produced during the development of MSCs to osteoblasts and differentially regulated during culture as well as by differentiation factors. The expression is maximal between proliferation and matrix maturation phase. However, UCN does not seem to act on the osteoblast itself as shown by the missing CRFR’s. Our results suggest new perspectives on the role of urocortin in human skeletal tissue in health and disease.