The angiotensin II/angiotensin II receptor system correlates with nodal spread in intestinal type gastric cancer

Impact of Angiotensin Converting Enzyme Inhibitors on Pathologic Complete Response With Neoadjuvant Chemotherapy for Muscle Invasive Bladder Cancer

INTRODUCTION

The renin-angiotensin system (RAS) has been demonstrated to modulate cell proliferation, desmoplasia, angiogenesis and immunosuppression. We examined the association of RAS inhibitors (RASi)-namely angiotensin converting enzyme inhibitors (ACEi) and angiotensin receptor blockers (ARB)-with neoadjuvant chemotherapy (NAC) for muscle-invasive bladder cancer (MIBC) preceding radical cystectomy (RC).

PATIENTS AND METHODS

We retrospectively investigated concurrent RASi use with NAC prior to RC in 302 patients with MIBC from 3 academic institutions. Outcomes included pathologic complete response (pCR) and overall survival (OS). Pathologic features, performance status (PS), clinical stage, type/number of cycles of NAC, and toxicities were collected.

RESULTS

Overall pCR rate was 26.2% and 5-year OS was 62%. Concurrent ACEi intake with NAC approached significance for association with pCR (odds ratio [OR] = 1.71; 95% CI, 0.94-3.11; P = .077). Patients with cT3/4N0-N1 disease receiving ACEi had higher pCR rates (30.8% vs. 17.7%, P = .056) than those not on ACEi. Female sex had a statistically significant favorable interaction for pCR with ACEi intake (P = .044). ACEi intake was not associated with OS, while pCR, PS and lower clinical stage were significantly associated with improved OS.

CONCLUSION

ACEi intake is potentially associated with increased pCR in patients with MIBC receiving NAC prior to RC, and this association is more pronounced in patients with higher clinical stage of disease at the initiation of therapy and female sex. Our data suggest the potential relevance of the RAS as a therapeutic target in aggressive MIBC.

Contribution of Endothelial Dysfunction to Cancer Susceptibility and Progression: A Comprehensive Narrative Review on the Genetic Risk Component

Venous thromboembolism (VTE) is a challenging clinical obstacle in oncological settings, marked by elevated incidence rates and resulting morbidity and mortality. In the context of cancer-associated thrombosis (CAT), endothelial dysfunction (ED) plays a crucial role in promoting a pro-thrombotic environment as endothelial cells lose their ability to regulate blood flow and coagulation. Moreover, emerging research suggests that this disorder may not only contribute to CAT but also impact tumorigenesis itself. Indeed, a dysfunctional endothelium may promote resistance to therapy and favour tumour progression and dissemination. While extensive research has elucidated the multifaceted mechanisms of ED pathogenesis, the genetic component remains a focal point of investigation. This comprehensive narrative review thus delves into the genetic landscape of ED and its potential ramifications on cancer progression. A thorough examination of genetic variants, specifically polymorphisms, within key genes involved in ED pathogenesis, namely eNOS, EDN1, ACE, AGT, F2, SELP, SELE, VWF, ICAM1, and VCAM1, was conducted. Overall, these polymorphisms seem to play a context-dependent role, exerting both oncogenic and tumour suppressor effects depending on the tumour and other environmental factors. In-depth studies are needed to uncover the mechanisms connecting these DNA variations to the pathogenesis of malignant diseases.

Genetic variants in the renin-angiotensin-aldosterone system: Impact on cancer risk, prognosis, and therapeutic directions

Although renin-angiotensin-aldosterone system (RAAS) is known to maintain blood pressure and electrolyte balance, it has recently been linked to a number of biological processes such as angiogenesis, tumorigenesis, metastasis, and cellular proliferation, increasing the risk of cancer development and progression. Multiple genetic variants have been found to affect the genes encoding RAAS components, altering gene transcription and protein expression. This review provides an up-to-date insight into the role of RAAS in carcinogenesis, as well as the impact of RAAS genetic variants on the risk of cancer development, progression, and patient survival and outcomes, as well as response to treatment. This paves the way for the application of precision medicine in cancer risk assessment and management by implementing preventative programs in individuals at risk and guiding the therapeutic direction in cancer patients.

The renin-angiotensin-aldosterone system (RAAS) signaling pathways and cancer: foes versus allies

The renin-angiotensin-aldosterone system (RAAS), is an old system with new fundamental roles in cancer biology which influences cell growth, migration, death, and metastasis. RAAS signaling enhances cell proliferation in malignancy directly and indirectly by affecting tumor cells and modulating angiogenesis. Cancer development may be influenced by the balance between the ACE/Ang II/AT1R and the ACE2/Ang 1-7/Mas receptor pathways. The interactions between Ang II/AT1R and Ang I/AT2R as well as Ang1-7/Mas and alamandine/MrgD receptors in the RAAS pathway can significantly impact the development of cancer. Ang I/AT2R, Ang1-7/Mas, and alamandine/MrgD interactions can have anticancer effects while Ang II/AT1R interactions can be involved in the development of cancer. Evidence suggests that inhibitors of the RAAS, which are conventionally used to treat cardiovascular diseases, may be beneficial in cancer therapies.Herein, we aim to provide a thorough description of the elements of RAAS and their molecular play in cancer. Alongside this, the role of RAAS components in sex-dependent cancers as well as GI cancers will be discussed with the hope of enlightening new venues for adjuvant cancer treatment.

An Update of G-Protein-Coupled Receptor Signaling and Its Deregulation in Gastric Carcinogenesis

G-protein-coupled receptors (GPCRs) belong to a cell surface receptor superfamily responding to a wide range of external signals. The binding of extracellular ligands to GPCRs activates a heterotrimeric G protein and triggers the production of numerous secondary messengers, which transduce the extracellular signals into cellular responses. GPCR signaling is crucial and imperative for maintaining normal tissue homeostasis. High-throughput sequencing analyses revealed the occurrence of the genetic aberrations of GPCRs and G proteins in multiple malignancies. The altered GPCRs/G proteins serve as valuable biomarkers for early diagnosis, prognostic prediction, and pharmacological targets. Furthermore, the dysregulation of GPCR signaling contributes to tumor initiation and development. In this review, we have summarized the research progress of GPCRs and highlighted their mechanisms in gastric cancer (GC). The aberrant activation of GPCRs promotes GC cell proliferation and metastasis, remodels the tumor microenvironment, and boosts immune escape. Through deep investigation, novel therapeutic strategies for targeting GPCR activation have been developed, and the final aim is to eliminate GPCR-driven gastric carcinogenesis.

Sex differences exist in brain renin-angiotensin system-regulating aminopeptidase activities in transplacental ethyl-nitrosourea-induced gliomas

INTRODUCTION

The renin angiotensin system (RAS) is emerging as an important target for the treatment of glioma. We had described that the local RAS is involved in vivo in tumor growth in the rat model of experimental C6 glioma implanted at the subcutaneous region, through the modification of several proteolytic regulatory enzymes of aminopeptidase type.

METHODS

We analyze RAS-regulating aminopeptidase activities in plasma and brain tissue of control male and female rats and rats with transplacental ethylnitrosourea-induced gliomas.

RESULTS

No differences were found either the mean total number of tumors per animal or the tumor volume between male and female animals. However, we have found increased levels in aspartyl aminopeptidase in both males and females and of aminopeptidase B only in males. On the contrary, decreased levels were found in aminopeptidase N and insulin-regulated aminopeptidase activities in both males and females, whereas aminopeptidase A only decreased in females. Decreased levels of aminopeptidase N, aminopeptidase B and insulin-regulated aminopeptidase were also shown in plasma of only female rats.

CONCLUSIONS

Under the complexity of RAS cascade, the changes found suggest the predominant actions of angiotensin III against a decreased action of angiotensin II and angiotensin IV. We conclude that angiotensin peptides are involved in tumor growth in this rat model of glioma and that their role in tumor growth can be analyzed through their corresponding proteolytic regulatory enzymes, which make them new and attractive therapeutic targets beyond the use or angiotensin converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs).

Angiotensin II receptor blockers valsartan and losartan improve survival rate clinically and suppress tumor growth via apoptosis related to PI3K/AKT signaling in nasopharyngeal carcinoma

BACKGROUND

Nasopharyngeal carcinoma (NPC) is a common type of head and neck cancer in Asia. Adverse effects occur in over 90% of NPC patients treated with radiotherapy or chemoradiation. Angiotensin II receptor blockers (ARBs) are commonly used to treat hypertension without serious adverse effects. However, the anticancer activity of ARBs in NPC remains unclear.

METHODS

We investigated the survival impacts of ARBs among NPC patients in a retrospective study. The anticancer effects and related signaling pathways of the ARBs valsartan and losartan were also evaluated in vitro and in vivo.

RESULT

A total of 927 patients with NPC who had hypertension were enrolled in the study, 272 (29.3%) of whom received ARBs. Kaplan-Meier analysis revealed that patients who used ARBs had higher rates of 5-year overall survival (OS; 87.8% vs 75.1%; P = .002) and disease-specific survival (DSS; 95.4% vs 77.7%; P < .001) than those who did not receive this treatment. Additionally, ARBs inhibited cell proliferation and induced apoptosis by increasing levels of cleaved caspase-3, cleaved caspase-9, and cytochrome C; the cell population in the sub-G1 phase; and caspase-3 activity in NPC-TW01 cells. ARBs inhibited tumor growth and angiogenesis via apoptosis in an NPC xenografts model. Interestingly, ARBs inhibited phosphorylation of PI3K/AKT signaling in vitro and in vivo, which is markedly attributed to their antitumor effects in NPC.

CONCLUSION

These data indicate that ARBs not only improve 5-year OS and DSS among patients with NPC but also exert antiproliferative and antiangiogenesis effects by inducing apoptosis in NPC, supporting that ARBs may be promising agents for treatment of NPC.

AT1R-Specific Ligand Angiotensin II as a Novel SPECT Agent for Hepatocellular Carcinoma Diagnosis

Hepatocellular carcinoma (HCC) is characterized by a high mortality and early diagnosis and treatment are critically needed. Ang II type 1 receptor (AT1R) has recently emerged as a potential molecular target for cancer diagnosis and intervention. Here, we labeled angiotensin II (Ang II), an AT1R ligand that is overexpressed in various solid cancers, with the near-infrared fluorescent dye, MPA, and radionuclide technetium-99m, and evaluated its capacity for HCC detection. These analyses were done in vitro using HepG2 (AT1R-positive) and BxPC3 (AT1R-negative) cell lines, and in vivo using a subcutaneous and orthotopic xenograft mouse model by fluorescence and SPECT imaging. Both Ang II-PEG₄-MPA- and [^99mTc]Tc-HYNIC-PEG₄-Ang II-bound AT1R exhibited a high affinity in vitro and [^99mTc]Tc-HYNIC-PEG₄-Ang II displayed an acceptable level of in vitro stability in rat plasma and whole blood. In vivo imaging revealed excellent specific tumor-targeting in HepG2 mouse xenografts models. In vitro and in vivo competition experiments revealed specific Ang II-PEG₄-MPA and [^99mTc]Tc-HYNIC-PEG₄-Ang II uptake by HepG2 cells and tumors. Altogether, AT1R-positive tumors were successfully detected via fluorescence and SPECT imaging using Ang II-PEG₄-MPA and [^99mTc]Tc-HYNIC-PEG₄-Ang II, respectively. Given their superior targeting capacity, Ang II-PEG₄-MPA and [^99mTc]Tc-HYNIC-PEG₄-Ang II are promising tools for HCC detection and warrant clinical translation.

Drug repurposing towards targeting cancer stem cells in pediatric brain tumors

In the pediatric population, brain tumors represent the most commonly diagnosed solid neoplasms and the leading cause of cancer-related deaths globally. They include low-grade gliomas (LGGs), medulloblastomas (MBs), and other embryonal, ependymal, and neuroectodermal tumors. The mainstay of treatment for most brain tumors includes surgical intervention, radiation therapy, and chemotherapy. However, resistance to conventional therapy is widespread, which contributes to the high mortality rates reported and lack of improvement in patient survival despite advancement in therapeutic research. This has been attributed to the presence of a subpopulation of cells, known as cancer stem cells (CSCs), which reside within the tumor bulk and maintain self-renewal and recurrence potential of the tumor. An emerging promising approach that enables identifying novel therapeutic strategies to target CSCs and overcome therapy resistance is drug repurposing or repositioning. This is based on using previously approved drugs with known pharmacokinetic and pharmacodynamic characteristics for indications other than their traditional ones, like cancer. In this review, we provide a synopsis of the drug repurposing methodologies that have been used in pediatric brain tumors, and we argue how this selective compilation of approaches, with a focus on CSC targeting, could elevate drug repurposing to the next level.

Oncogenic mechanisms in renal insufficiency

The prevalence of both cancer and end-stage renal disease is increasing. In addition, medical advances have meant increased survival rates for both diseases. Many chemotherapeutics are renally excreted, and conversely, renal insufficiency promotes a pro-neoplastic state, including genitourinary and other cancers. Dialysis prolongs life while increasing cancer risk. Proposed oncogenic mechanisms include immune dysfunction, chronic inflammation, changes in gut microbiota and stimulation of the renin-angiotensin system. This review summarizes current concepts in the relationship between cancer and renal insufficiency.

AGTR1 promotes lymph node metastasis in breast cancer by upregulating CXCR4/SDF-1α and inducing cell migration and invasion

The angiotensin II type I receptor (AGTR1) has a strong influence on tumor growth, angiogenesis, inflammation and immunity. However, the role of AGTR1 on lymph node metastasis (LNM) in breast cancer, which correlates with tumor progression and patient survival, has not been examined. AGTR1 was highly expressed in lymph node-positive tumor tissues, which was confirmed by the Oncomine database. Next, inhibition of AGTR1 reduced tumor growth and LNM in orthotopic xenografts by bioluminescence imaging (BLI). Losartan, an AGTR1-specific inhibitor, decreased the chemokine pair CXCR4/SDF-1α levels in vivo and inhibited AGTR1-induced cell migration and invasion in vitro. Finally, the molecular mechanism of AGTR1-induced cell migration and LNM was assessed by knocking down AGTR1 in normal cells or CXCR4 in AGTR1^high cells. AGTR1-silenced cells treated with losartan showed lower CXCR4 expression. AGTR1 overexpression caused the upregulation of FAK/RhoA signaling molecules, while knocking down CXCR4 in AGTR1^high cells downregulated these molecules. Collectively, AGTR1 promotes LNM by increasing the chemokine pair CXCR4/SDF-1α and tumor cell migration and invasion. The potential mechanism of AGTR1-mediated cell movement relies on activating the FAK/RhoA pathway. Our study indicated that inhibiting AGTR1 may be a potential therapeutic target for LNM in early-stage breast cancer.

Effect of Genetic Polymorphism on the Response to PDE5 Inhibitors in Patients With Erectile Dysfunction: A Systematic Review and a Critical Appraisal

INTRODUCTION

Several treatment strategies are nowadays available for erectile dysfunction (ED) patients. Currently, oral phosphodiesterase type 5 inhibitors (PDE5Is) are the first-line therapy for ED. However, they are effective in all treated cases with variable non-responsiveness. Many factors have been listed for this behavior, but the possibility of gene polymorphisms as an underlying cause has not been systematically investigated.

OBJECTIVES

This review aimed to assess the possible involvement of gene polymorphisms affecting the response to PDE5Is in men with ED.

METHODS

A systematic review was conducted based on a search of all relevant articles in various electronic sites such as PubMed, Medline Medical Subject Headings, Cochrane Library, Science Direct, Scopus, Embase, CINAHL, and Egyptian Knowledge Bank databases. Keywords used for relevant associations were sexual health, genes, variants, erectile dysfunction, polymorphisms, PDE5Is, and cavernous tissues.

RESULTS

Several studies have been carried out to determine the contribution of different encoded genes to ascertain the association between different genotypes and ED men who were non-responders for PDE5Is. 11 studies were selected for this review. In these studies, 6 investigated eNOS genetic polymorphism with variable outcomes. Only 1 study was carried out for each of the following genetic polymorphisms: phosphodiestrase 5A, G-protein β3 subunit, angiotensin converting enzyme, dimethylarginine dimethylaminohydrolase, arginase, and vascular endothelial growth factor with variable results.

CONCLUSION

Despite the relative shortage of available studies and the varied methodologies used, most of the research articles demonstrated a significant association between genetic polymorphism and the response to PDE5Is, especially for endothelial nitric oxide synthase polymorphism. The limited number of studies that investigated the possible effect of genetic polymorphism and the response to PDE5Is are challenged by many factors, particularly for the definition of responders and non-responders. This should be a motivating factor for researchers to perform further studies with a standardized methodology to address the influence of genetic variations on the response to PDE5Is. Mostafa T, Hassan A, Alghobary MF, et al. Effect of Genetic Polymorphism on the Response to PDE5 Inhibitors in Patients With Erectile Dysfunction: A Systematic Review and a Critical Appraisal. J Sex Med 2020;8:573-585.

Therapeutic potential of renin angiotensin system inhibitors in cancer cells metastasis

Metastasis is a complex process which contributes to the dissemination of cancer cells to other organs and forms new tumor sites. The proliferation of tumor cells is a necessary step for the initiation and progression of cancers and is associated with the formation of new vessels. In the latter stages of metastasis, cancer cells may spread into the extracellular matrix and may form metastatic nodules. Despite efforts to prevent this, effective therapies are limited in the treatment of some malignancies. Among the different tumor properties which could be usefully employed as a cancer target, metastasis may be one suitable target. The renin- angiotensin system is a physiological pathway that contributes to the proliferation of tumor cells, angiogenesis and the inflammatory response in tumor tissue. Angiotensin II (ANGII), a key peptide of this pathway, induces cell proliferation through the activation of two cellular pathways (mitogen-activated protein kinase (MAPK)-STAT3 and phosphoinositide 3-kinase (PI3K) -AKT pathway). AT1-R increases angiogenesis via the elevation of angiogenic factors expression (vascular endothelial growth factor (VEGF) and matrix metallopeptidases (MMPs)). The local activation of the RAS pathway increases the expression of ICAM, VCAM and MMPs genes that are involved in the late steps of the metastasis process. There is some evidence that RAS components are expressed in metastatic tumors and RASIs (renin-angiotensin system inhibitors) could be used to reduce cancer metastasis by affecting the mechanisms involved in several different cancers. Therefore, we have summarized the effects of RASIs, observed in pre-clinical and clinical studies of cancer cell metastasis.

Angiotensin I-converting enzyme inhibitors/angiotensin II receptor blockers may reduce tumor recurrence in left-sided and early colorectal cancers

BACKGROUND

Angiotensin signaling is suggested to be involved in tumorigenesis, tumor proliferation, and metastases. In colorectal cancer (CRC), it was demonstrated that angiotensin I-converting enzyme inhibitors (ACEIs) and angiotensin II receptor blockers (ARBs) may reduce the risk of CRC; however, their impact on tumor recurrence remains unknown. Therefore, in this study, we evaluated the impact of ACEIs/ARBs on tumor recurrence in CRC patients.

PATIENTS AND METHODS

We retrospectively investigated the clinicopathological data of 461 stage I-III CRC patients. We divided the patients into those who took an ACEI and/or ARB (the ACEI/ARB+ group) and those who did not (the ACEI/ARB- group), and we compared the two groups' recurrence-free survival (RFS) using a Kaplan-Meier curve analysis and log rank test. We also examined the impact of AGTR1 expression on tumor recurrence, using two public CRC datasets.

RESULTS

The Kaplan-Meier curves showed a trend toward improved RFS in the ACEI/ARB+ group versus the ACEI/ARB- group (p = 0.063). Subgroup analyses demonstrated that the RFS was significantly better in the ACEI/ARB+ group versus the ACEI/ARB- group in the patients with left-sided CRC (p = 0.030) and those with stage I CRC (p = 0.009). Consistent with these findings, the AGTR1 expression was higher in the left-sided versus right-sided colon (p = 0.048). High AGTR1 expression levels were associated with poor RFS in the GSE39582 dataset's stage I-III CRC patients (p < 0.001), and this finding was also validated in the GSE17536 dataset (p = 0.023).

CONCLUSION

ACEI/ARB treatment may reduce tumor recurrence in left-sided CRC and early-stage CRC.

Association of ACE I/D and AGTR1 A1166C Gene Polymorphisms and Risk of Uterine Leiomyoma: A Case-Control Study

Objective:

Uterine leiomyoma (UL) can be considered as the most common benign gynecological tumors of the smooth muscle cells in the myometrium. They are likely to be associated with infertility and recurrent abortion as well as obstructed labor and post-partum hemorrhage. Moreover, altered vascular-related genes can be linked to developing leiomyoma. Polymorphisms of the angiotensin-converting enzyme (ACE) gene are associated with some vascular diseases. The present study was carried out to investigate the association of ACE I/D and AGTR1A1166C gene polymorphisms and the risk of uterine leiomyoma in a sample of Iranian population.

Methods:

The study was carried out on a total of 413 women divided into 202 patients with diagnosed uterine leiomyomas and a control group of 211. Genotyping was performed using the PCR or PCR-RFLP methods.

Results:

The ID and DD genotypes of ACE I/D polymorphism were associated with 2 and 2.9 fold higher risk of UL compared to II genotype (OR, 2 [95% CI, 1.3 to 3.2]; P = 0.004 and OR, 2.9 [95% CI, 1.6 to 5]; P = 0.0002). The frequencies of ACE D alleles were 53.7% in women with UL and 40.3% in controls, which were observed to be statistically different (P < 0.0001). The alleles and genotypes of AGTR1 A1166C polymorphism were not different between UL and control women (P=0.9).

Conclusion:

The ACE ID and DD genotypes were associated with a higher risk of UL. No relationship was found between AGTR1A1166C polymorphism and UL.

Therapeutic Targeting of Cancer Stem Cells via Modulation of the Renin-Angiotensin System

Cancer stem cells (CSCs) are proposed to be the cells that initiate tumorigenesis and maintain tumor development due to their self-renewal and multipotency properties. CSCs have been identified in many cancer types and are thought to be responsible for treatment resistance, metastasis, and recurrence. As such, targeting CSCs specifically should result in durable cancer treatment. One potential option for targeting CSCs is by manipulation of the renin-angiotensin system (RAS) and pathways that converge on the RAS with numerous inexpensive medications currently in common clinical use. In addition to its crucial role in cardiovascular and body fluid homeostasis, the RAS is vital for stem cell maintenance and differentiation and plays a role in tumorigenesis and cancer prevention, suggesting that these roles may converge and result in modulation of CSC function by the RAS. In support of this, components of the RAS have been shown to be expressed in many cancer types and have been more recently localized to the CSCs in some tumors. Given these roles of the RAS in tumor development, clinical trials using RAS inhibitors either singly or in combination with other therapies are underway in different cancer types. This review outlines the roles of the RAS, with respect to CSCs, and suggests that the presence of components of the RAS in CSCs could offer an avenue for therapeutic targeting using RAS modulators. Due to the nature of the RAS and its crosstalk with numerous other signaling pathways, a systems approach using traditional RAS inhibitors in combination with inhibitors of bypass loops of the RAS and other signaling pathways that converge on the RAS may offer a novel therapeutic approach to cancer treatment.

Angiotensin-converting enzyme insertion/deletion gene polymorphisms and the risk of glioma in an Algerian population

Introduction

Just recently, it has been established that the angiotensin-converting enzyme (ACE) insertion/deletion (I/D) polymorphism is linked to the pathogenesis and to the evolution of human cancers. Therefore, the present study was concerned with the investigation of an eventual association between glioma and I/D polymorphism of the ACE gene.

Methods

The expression of ACE gene was detected by polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) analysis in 36 Algerian patients with glioma and 195 healthy controls.

Results

In glioma cases, allelic frequencies and genotypes distribution of the ACE I/D polymorphism were different from controls cases. ACE DD genotype were highly presented in glioma cases (63.9%) than controls (33.8%) and conferred 3.64-fold risk for predisposition in glioma cases (vs ID genotype, p<0.001). Recessive model (ACE II + ID genotypes vs DD) was associated with a 72% reduced risk of glioma (OR = 0.28, 95% CI: 0.13-0.60, p <0.001). Per copy D allele frequency was found higher in glioma cases (79.2%) than in controls (63.3 %), OR = 2.20, 95% CI: 1.20 - 4.03, p = 0.009.

Conclusion

The obtained data showed that the presence of the D allele might be a risk factor for the development of glioma. Further studies considering different ethnic groups with large samples are required to confirm this finding.

CARMA3 Is a Critical Mediator of G Protein-Coupled Receptor and Receptor Tyrosine Kinase-Driven Solid Tumor Pathogenesis

The CARMA–Bcl10–MALT1 (CBM) signalosome is an intracellular protein complex composed of a CARMA scaffolding protein, the Bcl10 linker protein, and the MALT1 protease. This complex was first recognized because the genes encoding its components are targeted by mutation and chromosomal translocation in lymphoid malignancy. We now know that the CBM signalosome plays a critical role in normal lymphocyte function by mediating antigen receptor-dependent activation of the pro-inflammatory, pro-survival NF-κB transcription factor, and that deregulation of this signaling complex promotes B-cell lymphomagenesis. More recently, we and others have demonstrated that a CBM signalosome also operates in cells outside of the immune system, including in several solid tumors. While CARMA1 (also referred to as CARD11) is expressed primarily within lymphoid tissues, the related scaffolding protein, CARMA3 (CARD10), is more widely expressed and participates in a CARMA3-containing CBM complex in a variety of cell types. The CARMA3-containing CBM complex operates downstream of specific G protein-coupled receptors (GPCRs) and/or growth factor receptor tyrosine kinases (RTKs). Since inappropriate expression and activation of GPCRs and/or RTKs underlies the pathogenesis of several solid tumors, there is now great interest in elucidating the contribution of CARMA3-mediated cellular signaling in these malignancies. Here, we summarize the key discoveries leading to our current understanding of the role of CARMA3 in solid tumor biology and highlight the current gaps in our knowledge.

Targeting the renin-angiotensin system to improve cancer treatment: Implications for immunotherapy

Renin-angiotensin system (RAS) inhibitors (RASi)-widely prescribed for the treatment of cardiovascular diseases-have considerable potential in oncology. The RAS plays a crucial role in cancer biology and affects tumor growth and dissemination directly and indirectly by remodeling the tumor microenvironment. We review clinical data on the benefit of RASi in primary and metastatic tumors and propose that, by activating immunostimulatory pathways, these inhibitors can enhance immunotherapy of cancer.

The role of angiotensin II in cancer metastasis: Potential of renin-angiotensin system blockade as a treatment for cancer metastasis

Hypertension, which often exists as a comorbid condition in cancer patients, is considered as a factor affecting cancer progression. The renin-angiotensin system (RAS) plays an important role in the regulation of blood pressure, and angiotensin II (Ang II) is a well-known pressor peptide in RAS. There is also accumulated evidence indicating that Ang II plays a critical role in the metastasis of various cancers by modulating adhesion, migration invasion, proliferation, and angiogenesis. Consistent with this, large epidemiological studies have reported the potential beneficial effects of angiotensin-converting enzyme (ACE) inhibitors and Ang II type 1 receptor blockers (ARBs) against cancer metastasis; however, some of the results remain controversial. Although the precise Ang II-related mechanisms involved in cancer metastasis are not completely clear yet, a number of basic and meta-analytic studies have shown that ACE inhibitors and ARBs reduce the metastatic potential of tumors. In this review, we summarize the relationships among hypertension, RAS, and metastasis as demonstrated in basic and clinical studies. Finally, we discuss the possibility of using RAS inhibitors as anti-metastatic drugs.

Do renin-angiotensin system inhibitors influence the recurrence, metastasis, and survival in cancer patients?: Evidence from a meta-analysis including 55 studies

BACKGROUND

Renin-angiotensin system inhibitors (RAS inhibitors) are antihypertensive agents with potential antitumor effects. However, various studies have yielded conflicting results on the influence of RAS inhibitors on survival of cancer patients. The aim of this study was to evaluate the effect of RAS inhibitors on recurrence, metastasis, and survival in cancer patients through a meta-analysis.

METHODS

PubMed, Web of Science, EMBASE, and Cochrane Library were systematically searched from inception to December 2016. The pooled hazard ratio (HR) with its 95% confidence interval (95% CI) was calculated to evaluate the association between RAS inhibitors and recurrence, metastasis, and survival in cancer patients.

RESULTS

Fifty-five eligible studies were included in the present meta-analysis. Results showed that there were significant improvements in overall survival (OS) (HR = 0.82; 95% CI: 0.77-0.88; P < 0.001), progression-free survival (HR = 0.74; 95% CI: 0.66-0.84; P < 0.001), and disease-free survival (HR = 0.80; 95% CI: 0.67-0.95; P = 0.01) in RAS inhibitor users compared with nonusers. Subgroup analyses revealed that the effect of RAS inhibitors on OS depended on the cancer type or different RAS inhibitors.

CONCLUSION

This meta-analysis suggests that RAS inhibitors could improve the survival of cancer patients and depend on cancer type and types of RAS inhibitors.

The use of angiotensin II receptor antagonists to increase the efficacy of radiotherapy in cancer treatment

Angiotensin II receptor antagonists inhibit various signaling pathways involved in the regulation of inflammation, apoptosis and angiogenesis. Radiation-induced activation of a proinflammatory cytokine network has been shown to mediate normal tissue injury induced by ionizing radiation in cancer patients, resulting in serious side effects. Hence, not only do angiotensin II receptor antagonists block inflammatory signaling both in cancer cells and in normal cells, but they are also effective in the treatment of cancer by inhibiting tumor progression, vascularization and metastasis. This review addresses the role of angiotensin II inhibitors in cancer therapy, and their potential to increase therapeutical index by protecting normal cells and sensitizing tumor cells to radiotherapy.

Angiotensin-(1-7) Suppresses Hepatocellular Carcinoma Growth and Angiogenesis via Complex Interactions of Angiotensin II Type 1 Receptor, Angiotensin II Type 2 Receptor and Mas Receptor

We recently confirmed that angiotensin II (Ang II) type 1 receptor (AT1R) was overexpressed in hepatocellular carcinoma tissue using a murine hepatoma model. Angiotensin(Ang)-(1-7) has been found beneficial in ameliorating lung cancer and prostate cancer. Which receptor of Ang-(1-7) is activated to mediate its effects is much speculated. This study was designed to investigate the effects of Ang-(1-7) on hepatocellular carcinoma, as well as the probable mechanisms. H22 hepatoma-bearing mice were randomly divided into five groups for treatment: mock group, low-dose Ang-(1-7), high-dose Ang-(1-7), high-dose Ang-(1-7) + A779 and high-dose Ang-(1-7) + PD123319. Ang-(1-7) treatment inhibited tumor growth time- and dose-dependently by arresting tumor proliferation and promoting tumor apoptosis as well as inhibiting tumor angiogenesis. The effects of Ang-(1-7) on tumor proliferation and apoptosis were reversed by coadministration with A779 or PD123319, whereas the effects on tumor angiogenesis were completely reversed by A779 but not by PD123319. Moreover, Ang-(1-7) downregulated AT1R mRNA, upregulated mRNA levels of Ang II type 2 receptor (AT2R) and Mas receptor (MasR) and p38-MAPK phosphorylation and suppressed H22 cell-endothelial cell communication. Thus, Ang-(1-7) administration suppresses hepatocellular carcinoma via complex interactions of AT1R, AT2R and MasR and may provide a novel and promising approach for the treatment of hepatocellular carcinoma.

Association of the ACE I/D gene polymorphisms with JAK2V617F-positive polycythemia vera and essential thrombocythemia

The renin-angiotensin system contributes to cell growth, proliferation, and differentiation in the bone marrow. We investigated the role of the ACE I/D gene polymorphism in 108 polycythemia vera (PV) and essential thrombocytosis (ET) patients who were positive for the JAK2V617F mutation, with a thrombosis group (TG) of 95 patients who had a history of vascular events, but did not have a history of myeloproliferative neoplasms and compared these to a healthy control group (CG) of 72 subjects. In the patients, II genotype and I allele frequency (p=0.009, odds ratio [OR]=9.716, 95% confidence interval [CI]=1.242-76.00, p=0.004, OR=2.019, 95% CI=1.243-3.280, respectively) were found to be higher than those in the controls. The DD genotype (p=0.021, OR=0.491, 95% CI=0.268-0.899) and D allele (p=0.004, OR=0.495, 95% CI=0.305-0.805) were found to be correlated with a decreased risk of a myeloproliferative neoplasm. These findings support the hypothesis that the ACE II genotype and I allele may be related to increased risk of ET and PV. Conversely, the DD genotype and D allele may be related to decreased risk of ET and PV. The results also indicated that the ACE I/D gene polymorphism was independent of thrombosis formation.

Podocalyxin promotes glioblastoma multiforme cell invasion and proliferation by inhibiting angiotensin-(1-7)/Mas signaling

Podocalyxin (PODX) reportedly enhances invasion in many human cancers including glioblastoma multiforme (GBM). Recent studies have shown that the local renin-angiotensin system (RAS) in tumor environment contributes significantly to tumor progression. As a counter-regulatory axis in RAS, angiotensin (Ang)-(1-7)/Mas signaling has been shown to inhibit the growth and invasiveness of several human cancers including GBM. In the present study, we examined the crosstalk between PODX and Ang-(1-7)/Mas signaling in GBM cells, and assessed its impact on GBM cell invasion and proliferation. A strong negative correlation between the expression of PODX and Mas in GBM tumor tissues from 10 consecutive patients (r=-0.768, p<0.01) was observed. The stable overexpression of PODX in LN-229 and U-118 MG human GBM cells decreased the expression of Mas at the mRNA and protein levels, which led to decreased density of Ang-(1-7)-binding Mas on the cell membrane. This effect was completely abolished by selective phosphatidylinositol 3-kinase (PI3K) inhibitor BKM120. By contrast, the stable knockdown of PODX in LN-229 and U-118 MG cells increased the expression of Mas and the density of Ang-(1-7)-binding Mas on the cell membrane. Overexpression and knockdown of PODX respectively reversed and enhanced the inhibitory effects of Ang-(1-7) on the expression/activity of matrix metalloproteinase-9 and cell invasion and proliferation in GBM cells. Although the overexpression of Mas showed no significant effect on the promoting effect of PODX on GBM cell invasion and proliferation in the absence of Ang-(1-7), it completely eliminated the effect of PODX in the presence of Ang-(1-7). In conclusion, to the best of our knowledge, the present study provided the first evidence that PODX inhibits Ang-(1-7)/Mas signaling by downregulating the expression of Mas through a PI3K-dependent mechanism in GBM cells. This effect led to enhanced GBM cell invasion and proliferation. The results of this study add new insight into the biological functions of PODX and the molecular mechanisms underlying GBM progression.

Angiotensin-converting enzyme insertion/deletion polymorphism and gastric cancer: a systematic review and meta-analysis

BACKGROUND AND OBJECTIVE

Several studies were launched to investigate the potential function of ACE I/D polymorphism in gastric cancer development and prognosis, but no conclusive results have been obtained. We conducted a systematic review and meta-analysis to evaluate the association between ACE I/D polymorphism and gastric cancer.

METHODS

A systemic search was performed in PubMed, Embase, China National Knowledge Infrastructure (CNKI), Wanfang and Weipu databases (until October 15,2013) to identify all published records on association between the ACE I/D polymorphism and gastric cancer. We adopted the odds ratio (OR) and 95% confidence interval (95%CI) as measure of effect. Meta-analysis was conducted using fixed/random-effects model in STATA 12.0.

RESULTS

Eventually a total of seven studies with 1392 cases and 2951 controls were included in our meta-analysis. No association was detected between ACE I/D polymorphism and gastric cancer susceptibility (DI+DD vs II: OR=1.06, 95%CI=0.92-1.21, P=0.443). However, we found that the DD genotype was significantly associated with increased lymph node metastasis (DD vs DI+II: OR=3.48, CI=1.77-6.85, P<0.001), and more advanced clinical stage (DD vs DI+II: OR=2.43, CI=1.34-4.39, P=0.003) of gastric cancer.

CONCLUSION

Our results indicated that ACE I/D polymorphism could not be directly associated with gastric cancer susceptibility, but might play important role in gastric cancer prognosis. Future studies with larger sample size are warranted for further evaluation.

Involvement of angiotensin II type 2 receptor (AT2R) signaling in human pancreatic ductal adenocarcinoma (PDAC): a novel AT2R agonist effectively attenuates growth of PDAC grafts in mice

We have recently discovered the potential involvement of angiotensin II type 2 receptor (AT2R) signaling in pancreatic cancer using AT2R deficient mice. To examine the involvement of AT2R expression in human PDAC, expressions of AT2R as well as the major angiotensin II receptor (type 1 receptor, AT1R) in human PDAC and adjacent normal tissue was evaluated by immunohistochemistry and real time PCR using surgically dissected human PDAC specimens. In immunohistochemical analysis, relatively strong AT1R expression was detected consistently in both normal pancreas and PDAC areas, whereas moderate AT2R expression was detected in 78.5% of PDAC specimens and 100% of normal area of the pancreas. AT1R, but not AT2R, mRNA levels were significantly higher in the PDAC area than in the normal pancreas. AT2R mRNA levels showed a negative correlation trend with overall survival. In cell cultures, treatment with a novel AT2R agonist significantly attenuated both murine and human PDAC cell growth with negligible cytotoxicity in normal epithelial cells. In a mouse study, administrations of the AT2R agonist in tumor surrounding connective tissue markedly attenuated growth of only AT2R expressing PAN02 murine PDAC grafts in syngeneic mice. The AT2R agonist treatment induced apoptosis primarily in tumor cells but not in stromal cells. Taken together, our findings offer clinical and preclinical evidence for the involvement of AT2R signaling in PDAC development and pinpoint that the novel AT2R agonist could serve as an effective therapeutic for PDAC treatment.

Sunitinib combined with angiotensin-2 type-1 receptor antagonists induces more necrosis: a murine xenograft model of renal cell carcinoma

Background. Angiotensin-2 type-1 receptor antagonists not are only antihypertensive drugs but also can inhibit VEGF production. We hypothesised that adding telmisartan to sunitinib could potentiate the antiangiogenic effects. Material and Methods. 786-O cell lines were injected in nude mice. After tumor development, mice were divided into 4 groups: the first was the control group (DMSO), the second group was treated with sunitinib alone, the third group was treated with telmisartan alone, and the fourth group was treated with the combination. Drugs were orally administered every day for four weeks. Animals were sacrificed after treatment. Blood and tumor tissues were collected for analysis by immunohistochemistry, Western Blot, and ELISA methods. Results. All animals developed a ccRCC and ten in each group were treated. Using a kinetic model, tumors tended to grow slower in the combination group compared to others (P = 0.06). Compared to sunitinib alone, the addition of telmisartan significantly increased tissue necrosis (P = 0.038). Central microvascular density decreased (P = 0.0038) as well as circulating VEGF (P = 0.003). There was no significant variation in proliferation or apoptosis markers. Conclusion. The combination of sunitinib and telmisartan revealed an enhancement of the blockage of the VEGF pathway on renal tumor resulting in a decrease in neoangiogenesis and an increase in necrosis.

[Ways to personalized medicine for gastric cancer]

Gastric cancer is the fourth most common tumor and the second most common cause of cancer-related deaths in the world. Approximately 70 % of the patients already have lymph node metastases at the time of the diagnosis leading to a median overall survival time of 16.7 months. Complete resection of the primary tumor with D2 lymphadenectomy offers the only chance of cure in the early stages of the disease. Survival of more locally advanced gastric cancer was improved by the introduction of perioperative, adjuvant and palliative chemotherapy of gastric cancer; however, the identification of novel predictive and diagnostic targets is urgently needed. Our own studies on gastric cancer biology identified several putative tumor biologically relevant G-protein-coupled receptors (e.g. AT1R, AT2R, CXCR4, FZD7, LGR4, LGR5, LGR6). Some of these receptors are also putative stem cell markers and may serve as future targets of an individualized therapy of gastric cancer.

The renin-angiotensin system meets the hallmarks of cancer

The hallmarks of cancer are described as the distinctive and complementary capacities that cells must acquire during the multistep development of becoming a cancer cell that allow them to survive, proliferate and disseminate. The renin-angiotensin system (RAS) was first discovered and extensively studied in the physiological regulation of systemic arterial pressure. RAS signalling increases cell proliferation in malignancy by directly affecting tumour and stromal cells and by indirectly modulating the growth of vascular cells during angiogenesis. We aim to describe and give a general view of how the RAS is involved in several hallmarks of cancer and how this could open a window to several interesting treatments.

[Renal toxicity of anti-VEGF (corrected) targeted therapies]

For a few years, new targeted therapies have been used for metastatic cancers, targeting VEGF and its receptors and improving patients' survival for metastatic carcinoma (kidney, GIST, breast, colorectal). The objective of these treatments is to block either circulating VEGF (bevacizumab; VEGF-Trap), or tyrosine kinase receptors (especially the VEGF receptor) (sorafenib, sunitinib, brivanib, imatinib, etc.). Indeed, VEGF stimulates endothelial cell proliferation and then tumour growth and metastasis. However, all these antiangiogenic drugs share similar side effects, most frequently gastrointestinal disturbance, skin toxicity and hypertension. Hypertension seems to be especially frequent in case of good response. Renal side effects have probably been underestimated in the first place and their exact frequency is not known, needing some specific trials and registries. Proteinuria, thrombotic microangiopathies and acute renal failures have been reported: renal biopsies might be necessary for precise evaluation of renal damages. Physiopathology seems very close to preeclampsia. Good collaboration between oncologists, nephrologists and cardiologists is therefore crucial in order to continue these targeted therapies safely for the patients.

Local bone marrow renin-angiotensin system in primitive, definitive and neoplastic haematopoiesis

The locally active ligand peptides, mediators, receptors and signalling pathways of the haematopoietic BM (bone marrow) autocrine/paracrine RAS (renin-angiotensin system) affect the essential steps of definitive blood cell production. Haematopoiesis, erythropoiesis, myelopoiesis, formation of monocytic and lymphocytic lineages, thrombopoiesis and other stromal cellular elements are regulated by the local BM RAS. The local BM RAS is present and active even in primitive embryonic haematopoiesis. ACE (angiotensin-converting enzyme) is expressed on the surface of the first endothelial and haematopoietic cells, forming the marrow cavity in the embryo. ACE marks early haematopoietic precursor cells and long-term blood-forming CD34(+) BM cells. The local autocrine tissue BM RAS may also be active in neoplastic haematopoiesis. Critical RAS mediators such as renin, ACE, AngII (angiotensin II) and angiotensinogen have been identified in leukaemic blast cells. The local tissue RAS influences tumour growth and metastases in an autocrine and paracrine fashion via the modulation of numerous carcinogenic events, such as angiogenesis, apoptosis, cellular proliferation, immune responses, cell signalling and extracellular matrix formation. The aim of the present review is to outline the known functions of the local BM RAS within the context of primitive, definitive and neoplastic haematopoiesis. Targeting the actions of local RAS molecules could represent a valuable therapeutic option for the management of neoplastic disorders.

[Angiotensin-2 type 1 receptors (AT1R) and cancers]

Recently, several meta-analysis suggested an increased risk of cancers linked to the use of antagonists of angiotensin-2 receptors or inhibitors of angiotensinogen converting enzyme. The results of epidemiological studies are conflicting. Meta-analysis as well as retrospective studies are not reliable and biased, since they have never been designed to explore any pro- or antitumoral effect. We lack of prospective studies that could take off the doubt on these drugs. Nevertheless, all experimental researches pointed out potent antitumoral properties. Indeed, direct antiproliferative and neo-angiogenic inhibition have been described on tumor cell cultures as well as on animal models. Moreover, we are convinced that the use of antagonists of angiotensin-2 receptors and inhibitors of angiotensinogen converting enzyme may be then of clinical use in the near future in association with classical antitumor drugs. In this review, we proposed to explore these data by a thorough analysis of recent literature associating epidemiological and experimental studies.

Angiotensin receptor blockers and tumorigenesis: something to be (or not to be) concerned about?

The possibility of carcinogenic side effects of antihypertensive therapies due to their chronic administration has been raised multiple times in the past. Recently, the issue has again drawn attention, this time in relation to angiotensin receptor blockers (ARBs). This, among others, caused both American and European drug regulation authorities to review the underlying evidence concerning the relationship between this class of medications and potential adverse carcinogenic outcome. A plethora of both basic science and preclinical evidence has been generated, and three meta-analyses and one nationwide cohort have focused on this specific question. The current review aims to summarize the contemporary multidisciplinary evidence on whether ARBs may be associated with an increased risk of tumorigenesis.

How does inhibition of the renin-angiotensin system affect the prognosis of advanced gastric cancer patients receiving platinum-based chemotherapy?

BACKGROUND

The renin-angiotensin system (RAS) is related to the regulation of cell proliferation, angiogenesis, and tumor progression.

PATIENTS AND METHODS

We retrospectively analyzed the effect of angiotensin I-converting enzyme inhibitors (ACEIs) and angiotensin II type-1 receptor blockers (ARBs) in 63 patients with advanced gastric cancer (AGC) with platinum-based chemotherapy. All patients analyzed had received medications for hypertension at the diagnosis of AGC. Patients were divided into two groups: an ACEI/ARB group (n = 30) and a non-ACEI/ARB group (n = 33).

RESULTS

Patient characteristics were not different between patients with and without ACEI/ARB. The response rate for all patients was 25.4% and the disease control rate was 77.8%. The median progression-free survival (PFS) for first-line chemotherapy was 5.5 months (95% CI 3.71-7.29) in the ACEI/ARB group and 4.3 months (95% CI 2.39-6.21) in the non-ACEI/ARB group (p = 0.506). There was a significant difference in overall survival (OS) in the ACEI/ARB group compared to the non-ACEI/ARB group (median OS: 8.2 vs. 13.9, p = 0.0095). In multivariate analysis, the use of ACEI/ARB was a significant independent prognostic factor for OS (p = 0.039) but not for PFS.

CONCLUSION

ACEI/ARB in combination with standard chemotherapy might improve survival in patients with AGC and hypertension. These results support further investigation into the anticancer effects of ACEL/ARB.

Angiotensin II induces apoptosis in intestinal epithelial cells through the AT2 receptor, GATA-6 and the Bax pathway

Angiotensin II (Ang II) has been shown to play an important role in cell apoptosis. However, the mechanisms of Ang-II-induced apoptosis in intestinal epithelial cells are not fully understood. GATA-6 is a zinc finger transcription factor expressed in the colorectal epithelium, which directs cell proliferation, differentiation and apoptosis. In the present study we investigated the underlying mechanism of which GATA-6 affects Ang-II induced apoptosis in intestinal epithelial cells. The in vitro intestinal epithelial cell apoptosis model was established by co-culturing Caco-2 cells with Ang II. Pretreatment with Angiotensin type 2 (AT2) receptor antagonist, PD123319, significantly reduced the expression of Bax and prevented the Caco-2 cells apoptosis induced by Ang II. In addition, Ang II up-regulated the expression of GATA-6. Interestingly, GATA-6 short hairpin RNA prevented Ang II-induced intestinal epithelial cells apoptosis and reduced the expression of Bax, but not Bcl-2. Taken together, the present study suggests that Angiotensin II promotes apoptosis in intestinal epithelial cells through GATA-6 and the Bax pathway in an AT2 receptor-dependent manner.

Role of renin-angiotensin system in gastric oncogenesis

The renin-angiotensin system (RAS) plays an important role not only in homeostasis but also in carcinogenesis. Recent epidemiological studies suggest that hypertensive patients with upregulated systemic RAS functions are at a significantly increased risk for the subsequent development of cancers with poor outcomes, and moreover that RAS inhibitors reduce tumor development, progression, and metastasis. Notably, Helicobacter pylori infection, one of the major predictors of gastric carcinogenesis, generally leads to RAS component overexpression, as exemplified by that of angiotensin I, angiotensin II, angiotensin I converting enzyme and angiotensin II receptor. Gastric mucosal RAS expression gradually increases with time after H. pylori infection with respect to the severity of inflammatory cell infiltration. Gastric carcinogenic potential is therefore considered to relate to RAS component expression levels and activities. This hypothesis is supported by findings that RAS genotypic variation can lead to high component expression levels (e.g. angiotensin I converting enzyme, chymase and angiotensinogen), and thereby increase the risk of development of gastric cancer. Thus, the RAS may be potently associated with the pathogenesis of H. pylori-related gastric carcinogenesis, and RAS inhibitors may provide tools for specifically preventing this disease.

Review article: the pathophysiological roles of the renin-angiotensin system in the gastrointestinal tract

BACKGROUND

The renin-angiotensin system (RAS) is a homeostatic pathway widely known to regulate cardiovascular and renal physiology; however, little is known about its influence in gastrointestinal tissues.

AIM

To elicit the anatomical distribution and physiological significance of the components of the RAS in the gastrointestinal tract.

METHODS

An extensive online literature review including Pubmed and Medline.

RESULTS

There is evidence for RAS involvement in gastrointestinal physiology and pathophysiology, with all the components required for autonomous regulation identified throughout the gastrointestinal tract. The RAS is implicated in the regulation of glucose, amino acid, fluid and electrolyte absorption and secretion, motility, inflammation, blood flow and possibly malignant disease within the gastrointestinal tract. Animal studies investigating the effects of RAS blockade in a range of conditions including inflammatory bowel disease, functional gut disorders, gastrointestinal malignancy and even intestinal ischaemia have been encouraging to date. Given the ready availability of drugs that modify the RAS and their excellent safety profile, an opportunity exists for investigation of their possible therapeutic role in a variety of human gastrointestinal diseases.

CONCLUSIONS

The gastrointestinal renin-angiotensin system appears to be intricately involved in a number of physiological processes, and provides a possible target for novel investigative and therapeutic approaches.

No association between ACE polymorphism and risk of nasopharyngeal carcinoma

Emerging evidence has shown that angiotensin I-converting enzyme (ACE) plays pivotal roles not only in the regulation of cardiovascular homeostasis but also in the process of tumorigenesis. A common ACE I/D polymorphism has been found to be functional, with the D allele displaying a higher plasma ACE level and ACE activity. The purpose of this study was to investigate whether the ACE I/D polymorphism was related to the risk of nasopharyngeal carcinoma (NPC). The study included 175 patients with NPC and 279 age- and sex-matched control subjects. The ACE I/D polymorphism was identified by a polymerase chain reaction analysis. No association was found between the ACE I/D polymorphism and risk of NPC (ID vs. II: odds ratio [OR] = 0.77, 95% confidence interval [CI] 0.51-1.17; DD vs. II: OR = 0.98, 95%CI 0.56-1.72, respectively). This finding indicates that the ACE I/D polymorphism may not play a role in susceptibility to NPC. Further studies are warranted to confirm this finding, especially in ethnically disparate populations.

Lack of association between gene polymorphisms of Angiotensin converting enzyme, Nod-like receptor 1, Toll-like receptor 4, FAS/FASL and the presence of Helicobacter pylori-induced premalignant gastric lesions and gastric cancer in Caucasians

Background

Several polymorphisms of genes involved in the immunological recognition of Helicobacter pylori and regulating apoptosis and proliferation have been linked to gastric carcinogenesis, however reported data are partially conflicting. The aim of our study was to evaluate potential associations between the presence of gastric cancer (GC) and high risk atrophic gastritis (HRAG) and polymorphisms of genes encoding Angiotensin converting enzyme (ACE), Nod-like receptor 1 (NOD1), Toll-like receptor 4 (TLR4) and FAS/FASL.

Methods

Gene polymorphisms were analyzed in 574 subjects (GC: n = 114; HRAG: n = 222, controls: n = 238) of Caucasian origin. ACE I/D (rs4646994), NOD1 796G>A (rs5743336), TLR4 3725G>C (rs11536889), FAS 1377G>A (rs2234767), FAS 670A>G (rs1800682) and FASL 844T>C (rs763110) were genotyped by different PCR approaches and restriction fragment length polymorphism analysis.

Results

Frequencies of genotypes in our study are similar to the data reported on subjects of Caucasian ethnicity. There was a tendency for NOD1 796G/G genotype to be associated with increased risk of HRAG (62.4% vs. 54.5% in controls, p = 0.082). FAS 670G/G genotype was more frequent in HRAG when compared to controls, 23.9% and 17.2% respectively, however it failed to reach significance level (p = 0.077). We did not find any significant associations for all polymorphisms in relation to GC or HRAG. NOD1 796G>A and TLR4 3725G>C gene polymorphisms were also not associated with Helicobacter pylori infection.

Conclusions

ACE, NOD1, TRL4 and FAS/FASL gene polymorphisms are not linked with gastric carcinogenesis in Caucasians, and therefore they should not be considered as potential biomarkers for identifying individuals with higher risk for GC.

The association between ACE polymorphism and risk of colorectal cancer in a Chinese population

OBJECTIVES

Angiotensin I-converting enzyme (ACE) plays crucial roles not only in the regulation of circulatory homeostasis but also in the pathology of carcinomas. An insertion-deletion (I/D) polymorphism in intron 16 of ACE gene was identified to be functional. We aimed to investigate the association between ACE I/D polymorphism and risk of colorectal cancer (CRC).

DESIGN AND METHODS

Using genomic DNA from 241 CRC patients and 299 control subjects, we genotyped the ACE I/D polymorphism using a polymerase chain reaction analysis.

RESULTS

We found that patients carrying the D allele were associated with an increased risk of developing poorly differentiated cancer and metastasis compared with those carrying the I allele (OR=1.54, 95%CI, 1.04-2.28; OR=1.56, 95%CI, 1.08-2.26, respectively), although no significant association was observed between cases and controls in overall analysis.

CONCLUSIONS

These findings indicate that the ACE I/D polymorphism is likely to play a role in CRC progression.

Insertion/deletion polymorphism of angiotensin I-converting enzyme gene is linked with chromophobe renal cell carcinoma

OBJECTIVES

To study the putative significance of angiotensin I-converting enzyme (ACE) in renal cell carcinoma (RCC). Recent evidence has suggested that a 287-base pair insertion (I)/deletion (D) polymorphism (rs4646994) of the angiotensin I-converting enzyme (ACE) might be associated with cancer risk and progression.

METHODS

The present case-control study accrued 383 subjects, including 210 with RCC and 173 age- and sex-matched healthy individuals without evidence or a history of cancer. Genomic DNA was extracted from the peripheral blood leukocytes. The ACE fragment containing the polymorphism was amplified using conventional polymerase chain reaction using specific primer pairs and subsequently genotyped using agarose gel electrophoresis.

RESULTS

Overall, a DD genotype and D allele were more frequently noted in the patients with RCC than in the controls (P = .042 and P = .045, respectively), and resulted from a greater frequency of DD and D in chromophobe RCC (P = .023 and P = .020, respectively). In contrast, the genotype and allele distribution of the controls and patients with papillary or clear cell RCC was similar. The II genotype was not observed in any patient with chromophobe RCC. On multivariate logistic regression analysis, the ACE genotype was an independent risk factor for chromophobe RCC (P = .012). Neither the ACE genotypes or alleles were associated with the tumor stage or grade.

CONCLUSIONS

The results of the present study have shown for the first time that the ACE insertion/deletion gene polymorphism rs4646994 might be linked with the development of chromophobe RCC. Neither the ACE genotypes nor the alleles were associated with RCC progression.

Angiotensin-2 receptors (AT1-R and AT2-R), new prognostic factors for renal clear-cell carcinoma?

Background:

The growth factor Angiotensin-2 signals through Angiotensin receptor type 1 (AT1-R) in a broad range of cell types and tumours and through the type-2 receptor (AT2-R) in a more restricted group of cell types. Although numerous forms of cancer have been shown to overexpress AT1-R, expression of AT1-R and AT2-R by human renal clear-cell carcinoma (RCCC) is not well understood. In this study, the expression of both angiotensin receptors was quantified in a retrospective series of RCCC and correlated with prognostic factors.

Methods:

Angiotensin receptor type 1 and AT2-R expressions were quantified on tumour tissues by immunohistochemistry (IHC), western blot and quantitative reverse transcriptase PCR (qRT–PCR). IHC results were correlated to Fuhrman's grade and patient progression-free survival (PFS).

Results:

A total of 84 RCCC were analysed. By IHC, AT1-R and AT2-R were expressed to a greater level in high-grade tumours (AT1-R: P<0.001, AT2-R: P<0.001). Univariate analysis showed a correlation between PFS and AT1-R or AT2-R expression (P=0.001). By multivariate analysis, only AT2-R expression correlated with PFS (HR 1.021, P=0.006) and cancer stage (P<0.001). By western blot, AT1-R and AT1-R were also found to be overexpressed in higher Fuhrman's grade (P<0.01 and P=0.001 respectively). By qRT–PCR, AT1-R but not AT2-R mRNA were downregulated (P=0.001 and P=0.118, respectively).

Conclusion:

Our results show that AT1-R and AT2-R proteins are overexpressed in the most aggressive forms of RCCC and that AT2-R expression correlates with PFS. AT1-R or AT2-R blockage could, therefore, offer novel directions for anti-RCCC therapy.

RAS polymorphisms in cancerous and benign breast tissue

Recent information has revealed new roles in the angiogenic processes linked to the rennin-angiotensin system. To date few studies have been done on the association between RAS genes and cancer and the majority focus mainly on angiotensin I-converting enzyme (ACE). For breast cancer there are three reports that include the angiotensin II receptor, subtype 1 (AGTR1), only one for angiotensinogen (AGT) and none for renin gene (REN). In the present study we investigate whether REN (Bgll), AGT (M235T), ACE (A245T, Indel), and AGTR1 (A1166C) are associated with breast cancer. Polymorphisms were analysed by PCR and RFPLs or sequence specific assay in three groups: breast cancer, benign breast disease (BBD) and general population. REN polymorphism shows that homozygous for A allele have an increased risk for BBD. Differences in M235T genotype frequencies were significant with less heterozygous in breast cancer. With different risk values ACE indel was associated with BBD and breast cancer. Association of AGTR1 was observed only in the breast cancer group, where C allele carriers present a reduced risk. Results of this work supports previous observations on the possible involvement of this system in breast cancer but it also suggests a role in benign disease.

The renin-angiotensin system and cancer: old dog, new tricks

For cancers to develop, sustain and spread, the appropriation of key homeostatic physiological systems that influence cell growth, migration and death, as well as inflammation and the expansion of vascular networks are required. There is accumulating molecular and in vivo evidence to indicate that the expression and actions of the renin-angiotensin system (RAS) influence malignancy and also predict that RAS inhibitors, which are currently used to treat hypertension and cardiovascular disease, might augment cancer therapies. To appreciate this potential hegemony of the RAS in cancer, an expanded comprehension of the cellular actions of this system is needed, as well as a greater focus on translational and in vivo research.

miR-802 regulates human angiotensin II type 1 receptor expression in intestinal epithelial C2BBe1 cells

Studies have demonstrated that angiotensin II (Ang II) can regulate intestinal fluid and electrolyte transport and control intestinal wall muscular activity. Ang II is also a proinflammatory mediator that participates in inflammatory responses such as apoptosis, angiogenesis, and vascular remodeling; accumulating evidence suggests that this hormone may be involved in gastrointestinal (GI) inflammation and carcinogenesis. Ang II binds to two distinct G protein-coupled receptor subtypes, the AT(1)R and AT(2)R, which are widely expressed in the GI system. Together these studies suggest that Ang II-AT(1)R/-AT(2)R actions may play an important role in GI tract physiology and pathophysiology. Currently it is not known whether miRNAs can regulate the expression of the human AT(1)R (hAT(1)R) in the GI system. PCR and in situ hybridization experiments demonstrated that miR-802 was abundantly expressed in human colon and intestine. Luciferase reporter assays demonstrated that miR-802 could directly interact with the bioinformatics-predicted target site harbored within the 3'-untranslated region of the hAT(1)R mRNA. To validate that the levels of miR-802 were physiologically relevant in the GI system, we demonstrated that miR-802 "loss-of-function" experiments resulted in augmented hAT(1)R levels and enhanced Ang II-induced signaling in a human intestinal epithelial cell line. These results suggest that miR-802 can modulate the expression of the hAT(1)R in the GI tract and ultimately play a role in regulating the biological efficacy of Ang II in this system.