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

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 peripheral corticotropin releasing factor family's role in vasculitis

Corticotropin releasing factor family peptides (CRF peptides) include 4 members, corticotropin releasing hormone (CRH), Urocortin (UCN1), UCN2 and UCN3. CRF peptides function via the two distinct receptors, CRF1 and CRF2. Among them, CRH/CRF1 has been recognized to influence immunity/inflammation peripherally. Both pro- and anti-inflammatory effects of CRH are reported. Likewise, UCNs, peripherally in cardiovascular system have been documented to have both potent protective and harmful effects, with UCN1 acting on both CRF1 & CRF2 and UCN2 & UCN3 on CRF2. We and others also observe protective and detrimental effects of CRF peptides/receptors on vasculature, with the latter of predominantly higher incidence, i.e., they play an important role in the development of vasculitis while in some cases they are found to counteract vascular inflammation. The pro-vasculitis effects of CRH & UCNs include increasing vascular endothelial permeability, interrupting endothelial adherens & tight junctions leading to hyperpermeability, stimulating immune/inflammatory cells to release inflammatory factors, and promoting angiogenesis by VEGF release while the anti-vasculitis effects may be just the opposite, depending on many factors such as different CRF receptor types, species and systemic conditions. Furthermore, CRF peptides' pro-vasculitis effects are found to be likely related to cPLA2 and S1P receptor signal pathway. This minireview will focus on summarizing the peripheral effects of CRF peptides on vasculature participating in the processes of vasculitis.

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.

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.

Diminished expression of CRHR2 in human colon cancer promotes tumor growth and EMT via persistent IL-6/Stat3 signaling

BACKGROUND & AIMS

Chronic inflammation promotes development and progression of colorectal cancer (CRC). We explored the distribution of Corticotropin-Releasing-Hormone (CRH)-family of receptors and ligands in CRC and their contribution in tumor growth and oncogenic EMT.

METHODS

mRNA expression of CRH-family members was analyzed in CRC (N=56) and control (N=46) samples, 7 CRC cell lines and normal NCM460 cells. Immunohistochemical detection of CRHR2 was performed in 20 CRC and 5 normal tissues. Cell proliferation, migration and invasion were compared between Urocortin-2 (Ucn2)-stimulated parental and CRHR2-overexpressing (CRHR2+) cells in absence or presence of IL-6. CRHR2/Ucn2-targeted effects on tumor growth and EMT were validated in SW620-xenograft mouse models.

RESULTS

CRC tissues and cell lines showed decreased mRNA and protein CRHR2 expression compared to controls and NCM460, respectively. The opposite trend was shown for Ucn2. CRHR2/Ucn2 signaling inhibited cell proliferation, migration, invasion and colony formation in CRC-CRHR2+ cells. In vivo, SW620-CRHR2+ xenografts showed decreased growth, reduced expression of EMT-inducers and elevated levels of EMT-suppressors. IL-1b, IL-6 and IL-6R mRNAs where diminished in CRC-CRHR2+ cells, while CRHR2/Ucn2 signaling inhibited IL-6-mediated Stat3 activation, invasion, migration and expression of downstream targets acting as cell cycle- and EMT-inducers. Expression of cell cycle- and EMT-suppressors was augmented in IL-6/Ucn2-stimulated CRHR2+ cells. In patients, CRHR2 mRNA expression was inversely correlated with IL-6R and vimentin levels and metastasis occurrence, while positively associated with E-cadherin expression and overall survival.

CONCLUSIONS

CRHR2 downregulation in CRC supports tumor expansion and spread through maintaining persistent inflammation and constitutive Stat3 activation. CRHR2^low CRC phenotypes are associated with higher risk for distant metastases and poor clinical outcomes.

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.

Corticotropin-releasing hormone receptors mediate apoptosis via cytosolic calcium-dependent phospholipase A₂ and migration in prostate cancer cell RM-1

Peripheral corticotropin-releasing hormone receptors (CRHRs) are G protein-coupled receptors that play different roles depending on tissue types. Previously, we discovered the mechanism of CRHR-mediated apoptosis of mouse prostate cancer cell line (RM-1) to be a change of Bcl-2:Bax ratio, and CRH was found to inhibit transforming growth factor β migration of breast cancer cells via CRHRs. In the present study, we investigated cytosolic calcium-dependent phospholipase A2 (cPLA2) bridging CRHR activations and Bcl-2:Bax ratio and the effect of CRHR activation on cell migration. Silencing of cPLA2 attenuated a CRHR1 agonist, CRH-induced apoptosis, and the decrease of the Bcl-2:Bax ratio, whereas silencing of cPLA2 aggravated CRHR2 agonist, Urocortin 2 (Ucn2)-inhibited apoptosis, and the increase of the Bcl-2:Bax ratio. CRH in a time- and concentration-dependent manner increased cPLA2 expression mainly through interleukin 1β (IL1β) upregulation. Ucn2 decreased cPLA2 expression through neither tumor necrosis factor α nor IL1β. CRH-suppressed decay of cPLA2 mRNA and Ucn2 merely suppressed its production. Overexpression of CRHR1 or CRHR2 in HEK293 cells correspondingly upregulated or downregulated cPLA2 expression after CRH or Ucn2 stimulation respectively. In addition, both CRH and Ucn2 induced migration of RM-1 cells. Our observation not only established a relationship between CRHRs and cell migration but also for the first time, to our knowledge, demonstrated that cPLA2 participates in CRHR1-induced apoptosis and CRHR2-inhibited apoptosis.

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.

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.

CRH suppressed TGFβ1-induced Epithelial-Mesenchymal Transition via induction of E-cadherin in breast cancer cells

Since its discovery in biopsies from breast cancer patients, the effect of corticotropin-releasing hormone (CRH) on carcinoma progression is still unclear. Transforming growth factorβ1 (TGFβ1) promotes Epithelial-Mesenchymal Transition (EMT) and induces Snail1 and Twist1 expressions. Loss of epithelial cadherin (E-cadherin) mainly repressed by Snail1 and Twist1, has been considered as hallmark of Epithelial-Mesenchymal Transition (EMT). Two breast cancer cell lines, MCF-7 and MDA-MB-231 were used to investigate the effect of CRH on TGFβ1-induced EMT by transwell chamber. And HEK293 cells were transiently transfected with CRHR1 or CRHR2 to explore the definite effects of CRH receptor. We reported that CRH inhibited migration of human breast cancer cells through downregulation of Snail1 and Twist1, and subsequent upregulation of E-cadherin. CRH inhibited TGFβ1-mediated migration of MCF-7 via both CRHR1 and CRHR2 while this inhibition in MDA-MB-231 was mainly via CRHR2. Ectopic re-expression of CRHR1 or CRHR2 respectively in HEK293 cells increased E-cadherin expression after CRH stimulation. Furthermore, CRH repressed expression of mesenchymal marker, N-cadherin and induced expression of Occludin, inhibiting EMT in MCF-7 & MDA-MB-231. Our results suggest that CRH may function as a tumor suppressor, at least partly by regulating TGFβ1-mediated EMT. These results may contribute to uncovering the effect of CRH in breast tumorigenesis and progression.

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.

Effects of contact dermatitis on hepatic gene expression in broilers

1. Severe foot and hock dermatitis in broiler chickens can reduce growth rate and increase susceptibility to bacterial infection, affecting both profitability and welfare. However, little is known about the underlying physiological changes associated with foot and hock lesions. 2. This study compared global hepatic gene expression in control birds and those with ammonia-induced foot and hock lesions using Agilent 44 K chicken oligonucleotide microarrays (8 birds per group). 3. In total, 417 genes were differentially expressed of which 174 could be mapped onto the genome. Genes associated with energy metabolism, thyroid hormone activity and cellular control were affected, while there was also evidence of an up-regulation of genes linked to a pro-inflammatory response. 4. It is conceivable that pain is the underlying cause for the observed changes in energy metabolism genes. 5. Changes in hepatic gene expression provide new information on how a chicken's physiological mechanisms alter to cope with foot and hock lesions. The findings support other data indicating that birds with increased severity of lesions are likely to be in pain and that growth will be compromised. Reduction of the incidence of dermatitis by improved husbandry should therefore benefit both welfare and commercial performance.

Single nucleotide polymorphisms associated with metastatic tumour antigen 1 overexpression in patients with hepatocellular carcinoma

BACKGROUNDS/AIMS

Metastatic tumour antigen 1 (MTA1) promotes angiogenesis by stabilizing hypoxia-inducible factor-1α (HIF-1α), which is closely associated with frequent postoperative recurrence and poor survival in patients with HCC. In this study, we determined single nucleotide polymorphisms (SNPs) in angiogenesis-related genes that are associated with MTA1 overexpression in HCC tissues.

METHODS

A total of 376 patients with HCC who had received curative surgical resection or liver transplantation were enrolled (312/21/43; HBV/HCV/NBNC). MTA1 expression was determined via immunohistochemistry. Thirty-three common SNPs sites (frequency ≥5%) in the angiogenic protein gene that are closely connected to one another were selected, including MTA1, VEGF, HIF-1α, FGF-2, and IGF-II.

RESULTS

Expression of MTA1 was detected in 120 HCC tissues (31%). An A allele at position IVS4-81G/A of the MTA1 gene (P = 0.016) and the TT genotype at position +12916C of the VEGF gene (P = 0.023) were significantly associated with MTA1 overexpression. However, the TT genotype at position -13021C (P = 0.011) and the haplotypes CT-CT (-11228C; -13021C) of the IGF-II gene (P(cor) = 0.033) were more common in patients with MTA1-negative HCC. Using multivariate analysis, the A allele at IVS4-81G/A in MTA1 gene (P = 0.015) and a T allele (TT+CT genotype) at -13021C in IGF-II (P = 0.002) were independent risk factors in HCC recurrence after curative surgical resection.

CONCLUSIONS

The genetic polymorphisms IVS4-81G/A in MTA1 and +12916C in VEGF genes were correlated with MTA1 overexpression. The SNPs in MTA1 and IGF-II genes may be important risk factors for the recurrence of HCC.

Different effects of corticotropin-releasing factor and urocortin 2 on apoptosis of prostate cancer cells in vitro

Urocortin (Ucn), a corticotropin-releasing factor (CRF)-related neuropeptide binding both CRF type 1 receptor (CRFR1) and CRFR2, has recently been found in prostate cancer. However, no report has yet been known to elucidate the roles of Ucn in prostate cancer via the two receptors. In this study, the expression of both CRFR1 and CRFR2 in the mouse prostate cancer cell line RM-1 were detected and cellular apoptosis was monitored in the presence of CRF or Ucn2, the CRFR1- and CRFR2-selective agonist respectively. CRF promoted apoptosis while Ucn2 exerted the opposite effect. CRF reduced Bcl-2 expression, induced Bax expression, and hyperpolarized the mitochondrial membrane potential to activate caspase-9. On the contrary, Ucn2 increased Bcl-2 expression and decreased Bax expression, in which phosphorylation of Akt and cyclic AMP response element-binding (CREB) was involved. Pretreatment with phosphatidylinositide 3-kinase/Akt inhibitor (LY-294002) prior to Ucn2 led to downregulation of CREB phosphorylation and hence reduced Bcl-2 expression. These effects of CRF and Ucn2 were abolished by antalarmin (Anta) and antisauvagine-30, the CRFR1- and CRFR2-selective antagonist respectively. In LNCaP cell line, similar effects on cell apoptosis by CRF and Ucn2 were observed. In summary, our results demonstrated CRFR1 and CRFR2 expression in prostate cancer and indicated the opposite apoptotic roles of the two different CRFRs. These data may contribute to uncovering the pathophysiological function of endogenous Ucn in prostate tumorigenesis and progression.

Urocortin 3 transgenic mice exhibit a metabolically favourable phenotype resisting obesity and hyperglycaemia on a high-fat diet

AIMS/HYPOTHESIS

Urocortins are the endogenous ligands for the corticotropin-releasing factor receptor type 2 (CRFR2), which is implicated in regulating energy balance and/or glucose metabolism. We determined the effects of chronic CRFR2 activation on metabolism in vivo, by generating and phenotyping transgenic mice overproducing the specific CRFR2 ligand urocortin 3.

METHODS

Body composition, glucose metabolism, insulin sensitivity, energy efficiency and expression of key metabolic genes were assessed in adult male urocortin 3 transgenic mice (Ucn3(+)) under control conditions and following an obesogenic high-fat diet (HFD) challenge.

RESULTS

Ucn3(+) mice had increased skeletal muscle mass with myocyte hypertrophy. Accelerated peripheral glucose disposal, increased respiratory exchange ratio and hypoglycaemia on fasting demonstrated increased carbohydrate metabolism. Insulin tolerance and indices of insulin-stimulated signalling were unchanged, indicating these effects were not mediated by increased insulin sensitivity. Expression of the transgene in Crfr2 (also known as Crhr2)-null mice negated key aspects of the Ucn3(+) phenotype. Ucn3(+) mice were protected from the HFD-induced hyperglycaemia and increased adiposity seen in control mice despite consuming more energy. Expression of uncoupling proteins 2 and 3 was higher in Ucn3(+) muscle, suggesting increased catabolic processes. IGF-1 abundance was upregulated in Ucn3(+) muscle, providing a potential paracrine mechanism in which urocortin 3 acts upon CRFR2 to link the altered metabolism and muscular hypertrophy observed.

CONCLUSIONS/INTERPRETATION

Urocortin 3 acting on CRFR2 in skeletal muscle of Ucn3(+) mice results in a novel metabolically favourable phenotype, with lean body composition and protection against diet-induced obesity and hyperglycaemia. Urocortins and CRFR2 may be of interest as potential therapeutic targets for obesity.

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.

Relevance of urocortins to cardiovascular disease

Acquired cardiovascular diseases such as coronary heart disease, peripheral artery disease and related vascular problems contribute to more than one-third of worldwide morbidity and mortality. In many instances, particularly in the under developed world, cardiovascular diseases are diagnosed at a late stage limiting the scope for improving outcomes. A range of therapies already exist for established cardiovascular disease, although there is significant interest in further understanding disease pathogenesis in order to improve diagnosis and achieve primary and secondary therapeutic goals. The urocortins are a group of recently defined peptide members of the corticotrophin-releasing factor family. Previous pre-clinical work and human association studies suggest that urocortins have potential to exert some beneficial and other detrimental effects on the heart and major blood vessels. More current evidence however favours beneficial effects of urocortins, for example these peptides have been shown to inhibit production of reactive oxygen species and vascular cell apoptosis, and thus may have potential to antagonise the progression of cardiovascular disease. This review summarises published data on the potential role of urocortins in cardiovascular disease.

Structural basis for hormone recognition by the Human CRFR2{alpha} G protein-coupled receptor

The mammalian corticotropin releasing factor (CRF)/urocortin (Ucn) peptide hormones include four structurally similar peptides, CRF, Ucn1, Ucn2, and Ucn3, that regulate stress responses, metabolism, and cardiovascular function by activating either of two related class B G protein-coupled receptors, CRFR1 and CRFR2. CRF and Ucn1 activate both receptors, whereas Ucn2 and Ucn3 are CRFR2-selective. The molecular basis for selectivity is unclear. Here, we show that the purified N-terminal extracellular domains (ECDs) of human CRFR1 and the CRFR2α isoform are sufficient to discriminate the peptides, and we present three crystal structures of the CRFR2α ECD bound to each of the Ucn peptides. The CRFR2α ECD forms the same fold observed for the CRFR1 and mouse CRFR2β ECDs but contains a unique N-terminal α-helix formed by its pseudo signal peptide. The CRFR2α ECD peptide-binding site architecture is similar to that of CRFR1, and binding of the α-helical Ucn peptides closely resembles CRF binding to CRFR1. Comparing the electrostatic surface potentials of the ECDs suggests a charge compatibility mechanism for ligand discrimination involving a single amino acid difference in the receptors (CRFR1 Glu104/CRFR2α Pro-100) at a site proximate to peptide residue 35 (Arg in CRF/Ucn1, Ala in Ucn2/3). CRFR1 Glu-104 acts as a selectivity filter preventing Ucn2/3 binding because the nonpolar Ala-35 is incompatible with the negatively charged Glu-104. The structures explain the mechanisms of ligand recognition and discrimination and provide a molecular template for the rational design of therapeutic agents selectively targeting these receptors.

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.

Corticorelin acetate, a synthetic corticotropin-releasing factor with preclinical antitumor activity, alone and with bevacizumab, against human solid tumor models

PURPOSE

Corticorelin acetate (CrA) is a synthetic form of corticotropin-releasing factor undergoing clinical trials in the treatment of peritumoral brain edema (PBE). We sought to investigate preclinically its potential as an antitumor agent against human solid tumors and to assess its ability to enhance the therapeutic activity of bevacizumab (BEV) in these same models.

METHODS

The in vivo efficacy of CrA as a single agent and in combination with the antiangiogenic agent, BEV, was examined in two preclinical human tumor models, the MX-1 breast and Colo-205 colon carcinomas. These models were selected based on their known sensitivity to BEV and were tumor types in which BEV has been approved for clinical use. The corneal micropocket assay was also performed to assess the antiangiogenic activity of CrA relative to BEV. The exposure level of CrA in the mouse using a typical preclinical regimen was measured so as to compare it to reported clinical exposure levels.

RESULTS

CrA was active as a single agent in the MX-1 breast carcinoma, but did not exhibit statistically significant activity as a single agent in the Colo-205 colon carcinoma under the doses and schedules used in the study. When BEV, which was active or near active in both the MX-1 and Colo-205 models, was administered concomitantly with CrA, therapeutic outcomes were observed that were significantly better than those obtained using either monotherapy. These therapeutic potentiations using CrA plus BEV were obtained in the absence of any observable increase in toxicities. CrA was active in the corneal micropocket assay, producing a substantial (>70%) inhibition of neovascularization. A representative CrA regimen in mice produced an exposure within eightfold of human exposure determined at one-half the current clinical dose.

CONCLUSIONS

The application of CrA for the treatment of PBE likely involves its activity as an antiangiogenic agent, which may be one possible mechanism to explain its observed preclinical antitumor activity. That activity, as well as its ability to provide an enhanced therapeutic outcome when given in conjunction with BEV in the absence of increased toxicity, supports the use of CrA clinically as other than a replacement therapy for dexamethasone in PBE.

Corticotropin-releasing hormone receptors mediate opposing effects in cholestasis-induced liver cell apoptosis

CRH receptors are expressed in human and rat liver. The current study investigated the biological role of the CRH system in the hepatocellular apoptotic process and aimed to reveal the responsible molecular mechanisms. Using a rat experimental model of common bile duct surgical ligation leading to obstructive jaundice and cholestasis, liver apoptosis was induced in the hepatic parenchyma as confirmed by the elevated expression of the early apoptotic neoepitope M30. This effect was reversed by administration of the nonselective CRH antagonist astressin but not by the selective CRH(2) antagonist astressin2B, suggesting that antagonism of the endogenous CRH(1) blocked the cholestasis-induced apoptotic mechanism. No effect was observed in the noncholestasis controls. In our experimental model, early and late apoptosis-preventing markers were induced in parallel to apoptosis; elevated gene transcript levels of the anti-apoptotic bcl-2 were found by real-time PCR in the first postoperative day and increased serum hepatocyte growth factor levels were measured by ELISA in the third postoperative day. Selective CRH(2) antagonism reversed the elevated expression of bcl-2 and hepatocyte growth factor, suggesting that this receptor type mediated antiapoptotic actions of the endogenous CRH system, opposing the preapoptotic ones mediated by CRH(1). In conclusion, the present study indicated that the CRH neuroendocrine system regulates cholestasis-induced apoptosis in the hepatic parenchyma via receptor-specific pathways. These data may contribute to better understanding of the CRH biology and its pathophysiological significance in the periphery.

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.

Differential regulation and roles of urocortins in human adrenal H295R cells

Three urocortins (Ucns) are known as members of the corticotropin-releasing factor (CRF) family of peptides and serve as natural ligands for CRF receptors. Ucn1 and Ucn3 exhibit potent effects on the adrenal system via the CRF receptors. This study aimed to explore the regulation and roles of Ucns in the adrenal system using human adrenal carcinoma H295R cells, which express Ucn1, Ucn2, Ucn3, CRF receptor type 1 (CRF(1) receptor), and CRF receptor type 2a (CRF(2a) receptor) mRNA. Forskolin, which stimulates adenylate cyclase and then increases intracellular cAMP production, was shown to transiently decrease Ucn1 and Ucn2 mRNA levels, but increase Ucns 1-3 mRNA levels in H295R cells. Steroidogenic acute regulatory protein, Cyp11beta1, and Cyp11beta2 mRNA levels, and both cortisol and aldosterone secretions were elevated by Ucn1. Cell viability was reduced by both Ucn1 and Ucn3 via the CRF(2) receptor in H295R cells. Ucn1 and Ucn3 increased the expression of the cAMP-response element binding protein and extracellular signal-related kinase (ERK) phosphorylations. The ERK and protein kinase A pathways were involved in Ucn3-decreased cell viability.

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.

Effect of Genistein on vasculogenic mimicry formation by human uveal melanoma cells

BACKGROUND

Vasculogenic mimicry (VM) was increasingly recognized as a form of aggressive melanoma acquiring blood supply. Genistein had attracted much attention as a potential anticancer agent. Therefore, we examined the effect of Genistein on VM in human uveal melanoma cells.

METHODS

VM structure was detected by periodic acid-Schiff (PAS) staining for uveal melanoma C918 cells cultured on the three-dimensional type I collagen gels after exposed to Genistein. We used reverse transcription polymerase chain reaction (RT-PCR) and Western Blot analysis to examine the effect of Genistein on vascular endothelial cadherin (VE-cadherin) mRNA and protein expression. The nude mice models of human uveal melanoma C918 cells were established to assess the number of VM using immunohistochemical and PAS double-staining.

RESULTS

Genistein inhibited the survival of C918 cells in vitro. The ectopic model study showed that VM in tumor tissue sections were significantly reduced by Genistein in vivo. In vitro, the VM structure was found in control, 25 and 50 microM Genistein-treatment groups but not in 100 and 200 microM. RT-PCR and Western Blot showed that 100 and 200 microM concentration of Genistein could significantly decrease VE-cadherin mRNA and protein expression of C918 cells compared with control (P < 0.05). However, the 25 and 50 microM Genistein slightly decreased the VE-cadherin level in vitro (P > 0.05).

CONCLUSION

Genistein inhibits VM formation of uveal melanoma cells in vivo and in vitro. One possible underlying molecular mechanism by which Genistein could inhibit VM formation of uveal melanoma is related to down-regulation of VE-cadherin.

Urocortin promotes the development of vasculitis in a rat model of thromboangiitis obliterans via corticotrophin-releasing factor type 1 receptors

BACKGROUND AND PURPOSE

Urocortin is a locally expressed pro-inflammatory peptide. Here we have examined the effects of urocortin on sodium laurate-induced peripheral arterial vasculitis in rats, modelling the mechanisms of thromboangiitis obliterans (TAO).

EXPERIMENTAL APPROACH

Peripheral vasculitis in rats was induced by sodium laurate and graded by gross appearance on the 12th day after injection. Histological changes in rat femoral arteries were assessed by histopathology and transmission electron microscopy. Blood cell counts, blood rheology, blood coagulation and plasma urocortin, thromboxane B(2), prostaglandin E(2) and soluble intercellular adhesion molecule-1 levels were measured. Expression of urocortin, corticotrophin-releasing factor (CRF(1/2)) receptors, cyclooxygenase (COX)-2 and intercellular adhesion molecule-1 (ICAM-1) at both mRNA and protein levels were determined by RT-PCR and Western blot.

KEY RESULTS

Rats showed grossly visible signs and symptoms of TAO on the 12th day after sodium laurate injection. In these rats, blood was in a hypercoagulable state; plasma urocortin, prostaglandin E(2) and soluble intercellular adhesion molecule-1 levels were elevated; and the expression of urocortin, CRF(1) and CRF(1alpha)-receptors, COX-2 and ICAM-1 in rat femoral arteries were markedly increased. Exogenous urocortin, given for 12 days after sodium laurate, exacerbated the hypercoagulable state and augmented expression of CRF(1alpha)-receptors, COX-2 and ICAM-1. These effects were abolished by a CRF(1)-receptor antagonist, NBI-27914, or a non-selective CRF-receptor antagonist, astressin, but not by the CRF(2)-receptor antagonist, antisauvagine-30, given with exogenous urocortin.

CONCLUSION AND IMPLICATIONS

Urocortin exacerbated the hypercoagulable state and vasculitis in a model of TAO induced by sodium laurate in rats, via CRF(1)-receptors. COX-2 and ICAM-1 might also have contributed to this exacerbation.

Urocortin 1 improves renal function in rats with streptozotocin-induced diabetes by inhibiting overproduction of TGF-beta 1 and VEGF

BACKGROUND AND PURPOSE

Renal function can be assessed by measuring albuminuria and glomerular filtration rate, and the latter is often estimated by creatinine clearance rate (Ccr). Transforming growth factor-beta1 (TGF-beta1) and vascular endothelial growth factor (VEGF) are two important factors involved in the progressive loss of renal function in diabetic nephropathy (DN), especially in terms of albuminuria. We investigated the effect of urocortin 1 on renal function of rats with DN and the mechanisms involved.

EXPERIMENTAL APPROACH

A modified rat model of DN (multiple injections of low-dose streptozotocin and complete Freund's adjuvant) and a rat mesangial cell line were used. Albuminuria and Ccr were measured or calculated. Expression and secretion of TGF-beta1 and VEGF were measured by immunohistochemistry, reverse transcription-polymerase chain reaction (RT-PCR) or enzyme-linked immunosorbent assay (R&D System, Inc., Minneapolis, MA, USA). Urocortin 1 and astressin [a non-selective antagonist of corticotrophin-releasing factor (CRF) receptors] were given as daily injections for 8 weeks.

KEY RESULTS

Treatment of DN rats with urocortin 1 decreased albuminuria, renal weight and overexpression of TGF-beta1 and VEGF but enhanced Ccr. Furthermore, VEGF mRNA was increased in kidneys of DN rats, and this increase was reduced by treatment with urocortin 1. The secretion of VEGF induced by TGF-beta1 in mesangial cells was inhibited by urocortin 1 pretreatment. Astressin given with urocortin 1 prevented most of the effects of urocortin 1, in our models, in vivo or in vitro.

CONCLUSION AND IMPLICATIONS

Our results strongly suggest that urocortin 1 improved renal function in rats with DN by inhibiting the overproduction of TGF-beta1 and VEGF.

The involvement of altered corticotropin releasing factor receptor 2 expression in prostate cancer due to alteration of anti-angiogenic signaling pathways

BACKGROUND

Expression of urocortin (Ucn) in the human benign prostate and prostate cancer has been reported recently. Ucn binds and activates corticotropin releasing factor (CRF) receptor 1 (CRFR1) and 2 (CRFR2). Activation of CRFR2 has been shown to inhibit tumor growth by regulation of proliferation and apoptosis as well as suppression of vascularization. However, there is no report demonstrating expression profile of CRFR2 in normal prostate versus prostate cancer.

METHODS

CRFR2 mRNA expression was assessed in human normal prostate and prostate cancer by reverse transcriptase PCR. CRFR2 expression on protein level has been performed using double staining immunofluorescence (IF) of tissue microarrays of 32 cases of prostatic adenocarcioma with corresponding normal tissues. Confocal microscopy was carried out to visualize the immunostaining.

RESULTS

PCR of normal prostate lysates exhibited specific signals for CRFR2 mRNA. However PCR of lysates of prostate cancer exhibited no signal for CRFR2 mRNA. IF study exhibited that smooth muscle components of the stroma and endothelial cells of blood vessels express an extensive staining for CRFR2. In a lesser extend vascular smooth muscle cells expressed CRFR2. The tumoral neovascular system and stroma exhibited no immunopositivity for CRFR2.

CONCLUSIONS

The present study demonstrates for the first time that human benign prostate tissue and prostate cancer specimen differentially express CRFR2. While Ucn expression in prostate cancer has been shown to be identical to non-malignant prostate tissues, we hypothesize that expression loss of CRFR2 in prostate cancer and its neovascularization contributes to prostate tumorigenesis, progression, and neoangiogenesis.