Angiotensin-converting enzyme gene insertion/deletion polymorphism and breast cancer risk

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.

Angiotensin-converting Enzyme Insertion/Deletion Polymorphism (rs4646994) and Susceptibility to Acute Lymphoblastic Leukemia: A Case–control Study

BACKGROUND: Angiotensin-converting enzyme (ACE) stimulates the proliferation of bone marrow hematopoietic progenitors and thought to be involved in pathological neoplastic hematopoiesis and leukemogenesis. AIM: This study aimed to investigate the association between ACE gene I/D polymorphism and the risk of acute lymphoblastic leukemia (ALL). MATERIALS AND METHODS: A total of 96 subjects were recruited for the study, 48 patients with ALL, and 48 apparently healthy volunteers as a control group. Genomic DNA was extracted from peripheral leukocytes and ACE I/D polymorphism was analysed using allele-specific polymerase chain reaction. RESULTS: In both study groups, the ACE D/D polymorphic genotype was the most frequent (52.1% and 54.2%, respectively), followed by the ID genotype (47.9% and 45.8% respectively), while the II genotype was completely absent in both study groups. The distribution of the polymorphic genotypes among the study groups was not significantly different (p = 0. 0.398). The frequency of the D allele was 0.76 in the patients and 0.77 in the control group, while the frequency of I allele was 0.24 in the patients and 0.23 in the control group. No deviation from Hardy–Weinberg equilibrium was observed (χ2 = 4.24, df = 1, p = 0.12). CONCLUSION: ACE I/D polymorphism is not associated with susceptibility to ALL among the Sudanese population.

Association of ACE I/D, -240A > T and AT1R A1166C polymorphisms with susceptibility to breast cancer: a systematic review and meta-analysis based on 35 case-control studies

The objective of this meta-analysis was to estimate the association of ACE I/D, -240 A > T and AT1R 1166 A > C polymorphisms with breast cancer (BC) risk. A comprehensive search on databases was conducted to identify all eligible case-control studies. Finally, 35 case-control studies, including 20 studies for ACE I/D, seven studies for ACE 240 A > T, and eight studies for AT1R 1166 A > C were included. The pooled analysis showed a significant association between ACE I/D polymorphism and BC risk under three genetic models, i.e., heterozygote (ID vs. DD: OR = 0.707, 95% CI 0.528-0.946, p = 0.020), homozygote (II vs. DD: OR = 0.662, 95% CI 0.462-0.947, p = 0.024), and dominant (II + ID vs. DD: OR = 0.691, 95% CI 0.507-0.941, p = 0.019). A significant association was also observed in ACE I/D polymorphism with BC risk among Asians and Caucasians. However, ACE -240 A > T and AT1R 1166 A > C polymorphisms were not associated with BC. Stratified analyses by ethnicity showed a significant association of ACE -240 A > T and AT1R 1166 A > C polymorphisms with BC risk in Latinos populations, but not in Asians. This meta-analysis inconsistence with all previous meta-analyses suggests that the ACE I/D might be associated with BC in overall and by ethnicity. However, the ACE -240 A > T and AT1R 1166 A > C were associated with BC risk only among Latinos populations.

Role of Renin-Angiotensin-System in Human Breast Cancer Cells: Is There a Difference in Regulation of Angiogenesis between Hormone-Receptor Positive and Negative Breast Cancer Cells?

Objective This study examined the role of the RAS in human breast cancer cells to question if there are differences between HR-positive and HR-negative cells with regard to regulation of VEGF. Methods Expression of different RAS components in hormone receptor (HR)-positive and HR-negative breast cancer cells was investigated using RT-PCR. Different stimulation protocols with different RAS inhibitors were used to investigate the effect on VEGF expression. Angiotensin II-dependent expression of VEGF was quantified by real time PCR. In addition, the effect of intrinsic RAS was studied performing siRNA knockdown of angiotensinogen (AGT). Statistical analysis were calculated using IBM SPSS Statistics Version 21. Results Expression of AT ₁ R, AT ₂ R, AGT and ACE was shown in HR-positive and HR-negative breast cancer cell lines. Extrinsic stimulation with angiotensin II increased VEGF significantly. After treatment with captopril or AT ₁ R-inhibitor candesartan, VEGF-expression decreased significantly in HR-positive and HR-negative cell lines. However, inhibition of AT ₂ R using PD 123,319 did not show any significant changes of VEGF. After prevention of intrinsic angiotensin II, extrinsic angiotensin II as well as the combination with inhibitors of the receptors caused a significant reduction of VEGF. Surprisingly, the overall effect of the RAS after knockdown of AGT revealed a significant increase of VEGF in HR-positive cells at any time while a significant decrease was observed in HR-negative cells after 144 hours incubation. Conclusion The RAS-dependent regulation of VEGF between HR-positive and HR-negative breast cancer cells seems do be different. These findings provide evidence for a possible future therapeutic strategy.

Prognostic value of soluble angiotensin II receptor 1 and soluble angiotensin converting enzyme (CD 143) in patients with acute leukemia

Background

The renin-angiotensin system (RAS) is a bioenzymic cascade that plays an integral role in cardiovascular homoeostasis by influencing vascular tone, fluid and electrolyte balance and the sympathetic nervous system. RAS was viewed as a circulating endocrine system, whereby renin released from the juxtaglomerular cells of the kidney cleaves the liver-derived macroglobulin precursor angio-tensinogen, to produce the inactive decapeptide angiotensin I, which is then converted to the active octapeptide Ang II by angiotensin converting enzyme (ACE) within the pulmonary. There is increasing evidence that Ang II, a major regulator of blood pressure and cardiovascular homeostasis, is involved in the regulation of cell proliferation, angiogenesis, inflammation and tissue remodeling, which suggests that this peptide might also play a role in cancer. Ang II is the main effector of the RAS and it alternatively binds to either Ang II T1R or Ang II T2R. The Ang II T1R and Ang II T2R can act as antagonists, and mediate effects on cell migration and proliferation of metastatic cancer cells and hemopoietic stem-progenitor cells. Components of the RAS are frequently differentially expressed in various cancers in comparison with their corresponding non- malignant tissue. Yet, the RAS has not been fully elucidated in patients with acute leukemia. Objective: The aim of the present work was to study serum level of Angiotensin II receptor type 1 and the soluble angiotensin converting enzyme (CD143) in patients with acute leukemia in order to extrapolate their possible prognostic value.

Subjects and Methods

The present study included 20 healthy volunteers clinically free from hypertension or sarcoidosis, 20 patients of newly diagnosed AML and 20 patients of newly diagnosed ALL. Blood samples were collected from all subjects and the level of serum ACE and serum Ang IIT1R were measured by enzyme linked immunossorbent assay.

Results

The activity of ACE (U/L) and the concentration of Ang IIT1R (U/L) in patients groups with either AML or ALL before therapy were significantly higher than in control group. After therapy, the activity of the enzyme and its receptor concentration in both groups of patients were significantly decreased but still significantly higher than in normal control subjects.

Conclusions

Estimating the serum level of ACE and soluble Ang IIT1R is of informative diagnostic and prognostic value. Estimation serum level of ACE and Ang IIT1R levels in patients with either AML or ALL is of value in deciding the treatment protocol.

Angiotensin Converting Enzyme Insertion/Deletion Polymorphism is Associated with Breast Cancer Risk: A Meta-Analysis

Background: A number of case-control studies were conducted to investigate the association of angiotensin converting enzyme insertion/deletion (ACE I/D) polymorphism with breast cancer. But the results remain controversial. This meta-analysis aims to comprehensively evaluate the association of ACE I/D polymorphism with breast cancer. Method: A comprehensive literature search on PubMed, Google Scholar, SCOPUS and ISI Web of Knowledge databases for studies published up to June 01, 2018 was performed. Summary odds ratios (ORs) and 95% confidence intervals (CI) were estimated. Publication bias of literatures was evaluated using funnel plots and Egger’s test. Results: A total of 20 studies including 2846 breast cancer cases 9,299 controls meeting the predefined criteria were involved in the meta-analysis. Overall, the ACE I/D polymorphisms was significantly associated with breast cancer under the allele model (I vs. D: OR= 0.803, 95% CI 0.647-0.996, p=0.046), the homozygote model (II vs. DD: OR= 0.662, 95% CI 0.462-0.947, p=0.024), the heterozygote model (ID vs. DD: OR= 0.707, 95% CI 0.528-0.946, p=0.020), the dominant model (II+ID vs. DD: OR= 0.691, 95% CI 0.507-0.941, p=0.019). In the subgroup analysis by ethnicity, a significant association was found among Asian and Caucasian populations, but not among mixed populations. Conclusions: This meta-analysis suggests that ACE I/D polymorphism may be associated with increased risk of breast cancer, especially among Asian and Caucasians. However, well-designed studies with larger sample size and more ethnic groups are needed to further validate the results.

A variety of gene polymorphisms associated with idiopathic granulomatous mastitis

Idiopathic granulomatous mastitis (IGM) is a rare and chronic inflammatory disorder. IGM mimics breast cancer regarding its clinical and radiological features. Etiology of IGM remains unclarified. Our patient was 37-year-old and 14 weeks pregnant. There was pain, redness and swelling in the right breast. The mass suggestive of malignancy was detected in sonography. Serum CA 125 and CA 15-3 levels were high. Genetic analysis was performed for the etiology. methylenetetrahydrofolate reductase (MTHFR) C 677 TT, β-fibrinogen-455 G>A, plasminogen activator inhibitor (PAI)-1 5 G/5 G, angiotensin-converting enzyme (ACE) I/D mutation was found. IGM was diagnosed by cor biopsy. An association was also reported between breast cancer and mutations in MTHFR-C 677 T, PAI-1, ACE genes. Genetic polymorphisms may involve in the development of IGM as it was seen in our case. Further studies should be conducted to better clarify this plausible association.

Angiotensin-converting enzyme insertion/deletion gene polymorphisms is associated with risk of glioma in a Chinese population

INTRODUCTION

The insertion/deletion (I/D) polymorphism of the angiotensin-converting enzyme (ACE) gene has recently been linked to the pathogenesis and progression of human cancers. The aim of this study was to evaluate the potential association between ACE I/D polymorphism and glioma in a Chinese population.

MATERIALS AND METHODS

A case-control study involving patients with 800 glioma and 800 controls was conducted. Polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) assay was applied to assess the ACE I/D genotypes.

RESULTS

Glioma cases had a significantly higher frequency of DD genotype [odds ratio (OR) = 1.61, 95% confidence interval (CI) = 1.12, 2.32; p = 0.01] than controls. When stratified by the grade of glioma, cases with WHO IV glioma had a significantly higher frequency of DD genotype (OR = 1.51, 95% CI = 1.03, 2.21; p = 0.03). When stratified by the histology of glioma, there was no significant difference in the distribution of each genotype.

CONCLUSION

Our study suggested that the ACE DD genotype was associated with a higher glioma risk in this Chinese population. To the best of our knowledge, this is the first report describing the potential association between ACE I/D polymorphism and glioma. Additional studies are needed to confirm this finding.

Angiotensin-converting enzyme and the tumor microenvironment: mechanisms beyond angiogenesis

The renin angiotensin system (RAS) is a network of enzymes and peptides that coalesce primarily on the angiotensin II type 1 receptor (AT1R) to induce cell proliferation, angiogenesis, fibrosis, and blood pressure control. Angiotensin-converting enzyme (ACE), the key peptidase of the RAS, is promiscuous in that it cleaves other substrates such as substance P and bradykinin. Accumulating evidence implicates ACE in the pathophysiology of carcinogenesis. While the role of ACE and its peptide network in modulating angiogenesis via the AT1R is well documented, its involvement in shaping other aspects of the tumor microenvironment remains largely unknown. Here, we review the role of ACE in modulating the immune compartment of the tumor microenvironment, which encompasses the immunosuppressive, cancer-promoting myeloid-derived suppressor cells, alternatively activated tumor-associated macrophages, and T regulatory cells. We also discuss the potential roles of peptides that accumulate in the setting of chronic ACE inhibitor use, such as bradykinin, substance P, and N-acetyl-seryl-aspartyl-lysyl-proline (Ac-SDKP), and how they may undercut the gains of anti-angiogenesis from ACE inhibition. These emerging mechanisms may harmonize the often-conflicting results on the role of ACE inhibitors and ACE polymorphisms in various cancers and call for further investigations into the potential benefit of ACE inhibitors in some neoplasms.

Lack of association of genetic polymorphisms of angiotensin converting enzyme 1 and angiotensin II type 1 receptor with breast cancer risk in Iranian population

We aimed to investigate the association of insertion/deletion (I/D) and A1166C polymorphisms of angiotensin I converting enzyme 1 and angiotensin II type 1 receptor genes, respectively and their combination on breast cancer risk in an Iranian population. A case-control study (70 cases, 70 controls) was performed on an Iranian population. The I/D and A1166C polymorphisms were analyzed by polymerase chain reaction (PCR) and restriction fragment length polymorphism PCR, respectively. The results revealed no significant difference between cases and controls in I/D (p = 0.14) and A1166C (p = 0.94) polymorphisms after adjustment for breast cancer known risk factors. In combined genotype analysis, considering DD and AA genotypes as low-risk genotypes, women with one and two high-risk genotypes (one high-risk genotype: adjusted odds ratio (OR), 1.24; two high-risk genotypes: adjusted OR, 1.97) were at higher risk for breast cancer. Also, the highest risk for breast cancer was seen in a subgroup of postmenopausal women carriers of two high-risk genotypes (adjusted OR, 2.41). In conclusion, I/D and A1166C polymorphisms are not significantly associated with breast cancer risk in the Iranian population; however, the combination of these two polymorphisms seems to have a synergic effect on the risk of breast cancer particularly in postmenopausal women, which may deserve consideration in large-scale case-control studies.

The roles of beta-adrenergic receptors in tumorigenesis and the possible use of beta-adrenergic blockers for cancer treatment: possible genetic and cell-signaling mechanisms

Cancer is the leading cause of death in the USA, and the incidence of cancer increases dramatically with age. Beta-adrenergic blockers appear to have a beneficial clinical effect in cancer patients. In this paper, we review the evidence of an association between β-adrenergic blockade and cancer. Genetic studies have provided the opportunity to determine which proteins link β-adrenergic blockade to cancer pathology. In particular, this link involves the major histocompatibility complex class II molecules, the renin-angiotensin system, transcription factor nuclear factor-kappa-light-chain-enhancer of activated B cells, poly(ADP-ribose) polymerase-1, vascular endothelial growth factor, and the reduced form of nicotinamide adenine dinucleotide phosphate oxidase. Beta-adrenergic blockers also exert anticancer effects through non-genomic factors, including matrix metalloproteinase, mitogen-activated protein kinase pathways, prostaglandins, cyclooxygenase-2, oxidative stress, and nitric oxide synthase. In conclusion, β-adrenergic blockade may play a beneficial role in cancer treatment. Additional investigations that examine β-adrenergic blockers as cancer therapeutics are required to further elucidate this role.

Association between polymorphisms of glutathione S-transferase genes (GSTM1, GSTP1 and GSTT1) and breast cancer risk in a sample Iranian population

Aim: Genetic and environmental factors are risk factors for breast cancer. Our aim was to investigate the associations between genetic polymorphism of GST genes (GSTM1, GSTT1 and GSTP1) and susceptibility to breast cancer in an Iranian population. Materials & methods: This case–control study was carried out on 134 patients with breast cancer and 152 healthy, cancer-free women. GSTP1 polymorphism was determined using tetra-primer amplification refractory mutation system PCR assay and GSTM1 and GSTT1 were genotyped by a multiplex PCR. Results: We found that the GSTM1 null genotype is a risk factor for predisposition to breast cancer (odds ratio [OR] = 2.01; 95% CI = 1.78–3.45; p = 0.010). No significant difference was found between the groups regarding GSTT1 null genotype (p > 0.05). The GSTP1 Ile/Val and Val/Val genotypes were associated with breast cancer risk (OR = 3.29; 95% CI = 1.84–5.91; p < 0.0001 and OR = 20.68; 95% CI = 5.66–75.60; p < 0.0001, respectively). Conclusion: In summary, GSTM1 and GSTP1, but not GSTT1 genetic polymorphisms are associated with increased risk of breast cancer in our population.

Angiotensin II type 1 receptor (AT-1R) expression correlates with VEGF-A and VEGF-D expression in invasive ductal breast cancer

Recent studies point to the involvement of angiotensin II (Ang II) receptor type 1 (AT-1R) on processes of metastasing, stimulation of invasiveness and angiogenesis in tumours. In this study, the correlation between intensity of AT-1R expression and expression of lymph- and angiogenesis markers in invasive ductal breast cancers (IDC) was examined. Immunohistochemical studies (IHC) were performed on archival material of 102 IDC cases. Only 28 (27.5%) cases manifested low AT-1R expression while 74 (72.5%) cases demonstrated a moderate or pronounced AT-1R expression. Expression intensity of AT-1R was found to correlate with expressions of VEGF-A (r = 0.26; p = 0.008) and VEGF-D (r = 0.24; p = 0.015). Out of the examined markers of angiogenesis and lymphangiogenesis only the pronounced expression of VEGF-C was found to correlate with patient poor clinical outcome (p = 0.009). The positive correlation between AT-1R and VEGF-A and VEGF-D could point to stimulatory action of Ang II on their expression what might result in augmented lymph- and angiogenesis in IDC.

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.

Angiotensin-converting enzyme insertion/deletion gene polymorphism in lung cancer patients

Lung cancer is a complex disease, and many factors, including environmental and occupational exposure, cigarette smoking, and genetics, contribute to its progression. Angiotensin-converting enzyme (ACE) is an important regulator of blood pressure and cardiovascular homeostasis. Plasma levels of ACE depend on an insertion/deletion (I/D) polymorphism in its gene. Current correlation data between lung cancer and the ACE I/D polymorphism are contradictory or insufficient. We investigated whether the ACE I/D polymorphism is associated with a risk for lung cancer development in the Croatian population, representing the first report in a population of Slavic origin. A total of 308 lung cancer patients and 353 control subjects were genotyped for the ACE I/D polymorphism by polymerase chain reaction. The observed distribution of genotypes and alleles showed no significant difference between total patients and controls (p>0.050). However, in a subgroup of nonsmall cell lung cancer patients with squamous cell carcinoma, a significantly higher frequency of the DD genotype (37.7% vs. 27.8%, p=0.030, OR=1.57, 95% CI=1.05-2.36) and D allele was observed compared with the control group (61.3% vs. 52.8%, p=0.015, OR=1.41, 95% CI=1.07-1.87). The DD genotype of ACE may contribute to a higher risk of developing squamous cell carcinoma in the Croatian population.

The renin-angiotensin system in the breast and breast cancer

Much evidence now suggests that angiotensin II has roles in normal functions of the breast that may be altered or attenuated in cancer. Both angiotensin type 1 (AT1) and type 2 (AT2) receptors are present particularly in the secretory epithelium. Additionally, all the elements of a tissue renin-angiotensin system, angiotensinogen, prorenin and angiotensin-converting enzyme (ACE), are also present and distributed in different cell types in a manner suggesting a close relationship with sites of angiotensin II activity. These findings are consistent with the concept that stromal elements and myoepithelium are instrumental in maintaining normal epithelial structure and function. In disease, this system becomes disrupted, particularly in invasive carcinoma. Both AT1 and AT2 receptors are present in tumours and may be up-regulated in some. Experimentally, angiotensin II, acting via the AT1 receptor, increases tumour cell proliferation and angiogenesis, both these are inhibited by blocking its production or function. Epidemiological evidence on the effect of expression levels of ACE or the distribution of ACE or AT1 receptor variants in many types of cancer gives indirect support to these concepts. It is possible that there is a case for the therapeutic use of high doses of ACE inhibitors and AT1 receptor blockers in breast cancer, as there may be for AT2 receptor agonists, though this awaits full investigation. Attention is drawn to the possibility of blocking specific AT1-mediated intracellular signalling pathways, for example by AT1-directed antibodies, which exploit the possibility that the extracellular N-terminus of the AT1 receptor may have previously unsuspected signalling roles.

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.

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.

Does angiotensin-converting enzyme polymorphism have association with symptomatic benign prostatic hyperplasia?

Objectives:

The aim of the study was to explore the putative significance of angiotensin-converting enzyme (ACE) insertion/deletion (I/D) polymorphism and its correlation with the lower urinary tract symptoms (LUTS) in benign prostatic hyperplasia (BPH).

Materials and Methods:

ACE I/D polymorphisms were determined by polymerase chain reaction (PCR) in 200 patients with moderate to severe LUTS due to BPH and 200 patients of same age group without the LUTS having normal size prostate. ACE levels were estimated by spectrophotometer method. Logistic regression models were used to determine the genetic effects using SPSS statistical software (version 12.0).

Results and Conclusions:

The distribution of genotypes along with allelic frequency and carriage rate did not significantly differ between study and control groups. This study suggests that I/D polymorphisms within the ACE gene are not associated with the presence of LUTS in BPH patients. Future studies in large cohorts are needed that may reveal the spectrum of cellular mechanism mediated by ACE relevant to pathophysiology of BPH and effect of ethnic differences.

Association between polymorphisms of the renin-angiotensin system genes and breast cancer risk: a meta-analysis

The renin-angiotensin system (RAS) has been considered to be implicated in the development of breast cancer. However, the results are inconsistent. In this study, we conducted a meta-analysis to assess the association between four polymorphisms, including angiotensin I-converting enzyme (ACE) I/D and A240T, angiotensin II type 1 receptor (AGTR1) A1166C and angiotensinogen (AGT) M235T polymorphisms, and breast cancer risk. Published literature from PubMed, ISI web of science, and Embase databases were retrieved. All studies evaluating the association between ACE I/D, ACE A240T, AGTR1 A1166C, or AGT M235T polymorphism and breast cancer risk were included. Pooled odds ratio (OR) with 95% confidence interval (CI) was calculated using fixed- or random-effects model. Ten studies (1,650 cases and 9,283 controls) on ACE I/D polymorphism, six studies (1,316 cases and 2,632 controls) on ACE A240T polymorphism, three studies (235 cases and 601 controls) on AGTR1 A1166C polymorphism, and two studies (273 cases and 3,547 controls) on AGT M235T polymorphism were included. Overall, the meta-analysis showed no significant association between I/D or A240T polymorphism and breast cancer risk in either genetic model. Further subgroup analysis by ethnicity also revealed non-significant association in Caucasian or Asian populations except for Africans (the statistically significant association for ACE I/D or A240T polymorphism in Africans derived from only one study). A marginally significant association was observed for AGTR1 A1166C polymorphism in Caucasians (CC vs. AA: OR = 0.31, 95% CI 0.10-0.99). In addition, there was a significant association between AGT M235T polymorphism and breast cancer risk in Caucasians (OR = 1.45, 95% CI 1.12-1.88). The present meta-analysis suggested that ACE I/D and A240T polymorphisms might not be a good predictor of breast cancer risk, while AGTR1 A1166C and AGT M235T polymorphisms might be implicated in the pathogenesis of breast cancer. Given the limited sample size, the findings warrant further investigation.

Association of angiotensin I converting enzyme insertion/deletion polymorphism with breast cancer: a meta-analysis

Background: Polymorphisms of angiotensin I converting enzyme (ACE) gene have been inconsistently associated with breast cancer risk. We examined these associations by performing a meta-analysis.

Materials and methods: Four studies (cases: 1422; controls: 3044) testing the association between ACE insertion/deletion (I/D) polymorphism and breast cancer were examined. The analyses were performed using the Review Manager 5.0.25 software package.

Results: The combined results based on the above four studies showed that there was no significant difference in genotype distribution (DD, ID or II) between breast cancer patients and controls, with the odds ratio (OR) (1.00; 0.94; 1.11) and 95% confidence interval (CI) (0.76 to 1.33; 0.83 to 1.07; 0.96 to 1.28) for DD, ID and II genotype respectively.

Conclusion: The meta-analysis suggests that ACE I/D polymorphism may not be a genetic risk factor for breast cancer.

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.

Angiotensin I-converting enzyme insertion/deletion polymorphism and increased risk of gall bladder cancer in women

Gall bladder cancer (GBC) is a relatively rare but highly fatal disease, particularly in North India. The angiotensin I-converting enzyme (ACE) insertion/deletion (I/D) gene polymorphism influences serum angiotensin II action, which has been associated with various malignancies. This population-based case-control study was undertaken to examine the potential association of ACE I/D variation with GBC in a North Indian population. Genotypes and allelic frequencies of the ACE I/D polymorphism (rs4646994) were determined for 233 GBC patients and 260 cancer-free controls randomly selected from the population using polymerase chain reaction. Odds ratio (OR) and 95% confidence interval were calculated in multivariate logistic regression analysis for the association of ACE polymorphism with GBC. The ACE I/D polymorphism was found to be nonsignificantly associated with an overall increased risk of GBC (OR = 1.04 and 1.38 for I/D and D/D genotypes, respectively; p(trend) = 0.375). The increased risk was predominant significantly in female cohort and nonsignificantly in GBC patients with gallstone status (OR = 1.63; p = 0.039 and OR = 1.37; p = 0.187, respectively). In summary, ACE I/D polymorphism may alter the susceptibility to GBC, especially in women.

Progesterone receptor A-regulated gene expression in mammary organoid cultures

Progesterone, through the progesterone receptor (PR), promotes development of the normal mammary gland and is implicated in the etiology of breast cancer. We identified PRA-regulated genes by microarray analysis of cultured epithelial organoids derived from pubertal and adult mouse mammary glands, developmental stages with differing progesterone responsiveness. Microarray analysis showed significant progestin (R5020)-regulation of 162 genes in pubertal organoids and 104 genes in adult organoids, with 68 genes regulated at both developmental stages. Greater induction of receptor activator of NFkappaB ligand and calcitonin expression was observed in adult organoids, suggesting possible roles in the differential progesterone responsiveness of the adult and pubertal mammary glands. Analysis of the R5020-responsive transcriptome revealed several enriched biological processes including cell adhesion, immune response, and survival. R5020 both induced Agtr1 and potentiated angiotensin II-stimulated proliferation, highlighting the functional significance of the latter process. Striking up-regulation of genes involved in innate immunity processes included the leukocyte chemoattractants serum amyloid A1, 2 and 3 (Saa1, 2, 3). In vivo analysis revealed that progesterone treatment increased SAA1 protein expression and leukocyte density in mammary gland regions undergoing epithelial expansion. These studies reveal novel targets of PRA in mammary epithelial cells and novel linkages of progesterone action during mammary gland development.

AGTR1 overexpression defines a subset of breast cancer and confers sensitivity to losartan, an AGTR1 antagonist

Breast cancer patients have benefited from the use of targeted therapies directed at specific molecular alterations. To identify additional opportunities for targeted therapy, we searched for genes with marked overexpression in subsets of tumors across a panel of breast cancer profiling studies comprising 3,200 microarray experiments. In addition to prioritizing ERBB2, we found AGTR1, the angiotensin II receptor type I, to be markedly overexpressed in 10-20% of breast cancer cases across multiple independent patient cohorts. Validation experiments confirmed that AGTR1 is highly overexpressed, in several cases more than 100-fold. AGTR1 overexpression was restricted to estrogen receptor-positive tumors and was mutually exclusive with ERBB2 overexpression across all samples. Ectopic overexpression of AGTR1 in primary mammary epithelial cells, combined with angiotensin II stimulation, led to a highly invasive phenotype that was attenuated by the AGTR1 antagonist losartan. Similarly, losartan reduced tumor growth by 30% in AGTR1-positive breast cancer xenografts. Taken together, these observations indicate that marked AGTR1 overexpression defines a subpopulation of ER-positive, ERBB2-negative breast cancer that may benefit from targeted therapy with AGTR1 antagonists, such as losartan.

Role of the renin-angiotensin system in prostate cancer

Prostate cancer is highly prevalent in Western society, and its early stages can be controlled by androgen ablation therapy. However, the cancer eventually regresses to an androgen-independent state for which there is no effective treatment. The renin-angiotensin system (RAS), in particular the octapeptide angiotensin II, is now recognised to have important effects on growth factor signalling and cell growth in addition to its well known actions on blood pressure, fluid homeostasis and electrolyte balance. All components of the RAS have been recently identified in the prostate, consistent with the expression of a local RAS system in this tissue. This review focuses on the role of the RAS in the prostate, and the possibility that this pathway may be a potential therapeutic target for the treatment of prostate cancer and other prostatic diseases.

Angiotensin inhibition and malignancies: a review

After an early report that patients treated with angiotensin-converting enzyme (ACE) inhibitors had a lower than expected incidence of cancers, there was a large number of publications investigating the possible pathophysiological mechanism mediating this effect, as well as population studies comparing the incidence of cancers in patients treated with agents inhibiting the renin-angiotensin system with their incidence in the general population. Several mechanisms are proposed to explain a potential anti-tumour activity of such agents in vitro in experimental animal models. However, the population studies are mostly inconclusive, although they do suggest a possible interaction between ACE genotypes and susceptibility to altered behaviour of certain tumours.

The kallikrein-kinin system in health and in diseases of the kidney

Since kallikrein was discovered as a vasodilatory substance in human urine, the kallikrein-kinin system (KKS) has been considered to play a physiological role in controlling blood pressure. Gene targeting experiments in mice in which the KKS has been inactivated to varying degrees have, however, questioned this role, because basal blood pressures are not altered. Rather, these experiments have shown that the KKS has a different and important role in preventing changes associated with normal senescence in mice, and in reducing the nephropathy and accelerated senescence-associated phenotypes induced in mice by diabetes. Other experiments have shown that the KKS suppresses mitochondrial respiration, partly by nitric oxide and prostaglandins, and that this suppression may be a key to understanding how the KKS influences senescence-related diseases. Here we review the logical progression and experimental data leading to these conclusions, and discuss their relevance to human conditions.

Renin-angiotensin system inhibitors, angiotensin I-converting enzyme gene insertion/deletion polymorphism, and cancer: the Rotterdam Study

BACKGROUND

Angiotensin I-converting enzyme (ACE) inhibitors, angiotensin II antagonists, and the ACE insertion/deletion (I/D) gene polymorphism all influence serum angiotensin II action. Because angiotensin II levels have been associated with cancer, the objective of the current epidemiologic study was to investigate whether renin-angiotensin system inhibitors and/or ACE genotypes were associated with an altered risk of colorectal, lung, breast, and prostate cancer.

METHODS

Data were obtained from the Rotterdam Study, a population-based, prospective cohort study with 7983 participants. Participants who had a history of 1 of the cancers of interest (n = 216) or who had a medication history <6 months (n = 88) were excluded, leaving 7679 participants, of whom the ACE genotypes could be assessed in 6670 individuals. The mean follow-up was 9.6 years, during which 730 incident cancers occurred. The effect of medication, ACE I/D genotypes, and their interaction on cancer risk and progression was studied by using Cox proportional hazard models.

RESULTS

Carriers of the high-activity genotype DD had an increased risk of breast cancer compared with low-activity II/ID genotype carriers (hazard ratio [HR], 1.47; 95% confidence interval [95% CI], 1.05-2.04), but no association was demonstrated for other cancers. DD carriers who were exposed to long-term and high-dose medication were at lower risk for cancer (HR, 0.28; 95% CI, 0.10-0.79). Short-term, high-dose users were at risk for colorectal cancer progression in the II/ID stratum (HR, 3.83; 95% CI, 1.67-8.79).

CONCLUSIONS

Renin-angiotensin system-inhibiting drugs seemed to protect against cancer in individuals with the DD genotype, which was associated with high levels of ACE.

Genetic Basis of Physical Fitness

Environmental stimuli interact with common genetic variants to determine individual characteristics including physical performance: ∼80% of variation in arm eccentric flexor strength and grip strength may be genetically determined. However, many physical characteristics and physiological processes determine physical performance, and each is regulated by a large number of genes: strong genetic influences on maximum exertional oxygen uptake, heart size, lean mass, skeletal muscle growth, and bone mineral density have all been described. To date few variants strongly influencing global performance have been identified. One such is the presence (Insertion, I allele) rather than absence (Deletion, D allele) of a DNA segment in the gene encoding angiotensin-converting enzyme (ACE): The I allele has been associated with fatigue resistance/endurance, and the D-allele with strength gain.

Diet and breast cancer: a review of the prospective observational studies

The role of diet for the risk of breast cancer is of great interest as a potentially modifiable risk factor. The evidence from prospective observational studies was reviewed and summarized on selected dietary factors, gene-diet interactions, and breast cancer incidence. Dietary factors were considered that, based on their nutritional constituents, are of particular interest in the context of breast cancer: fat intake, biomarkers of fat intake, fruit and vegetable consumption, antioxidant vitamins (vitamins A, C, E, and beta-carotene), serum antioxidants, carbohydrate intake, glycemic index and glycemic load, dairy consumption (including vitamin D), consumption of soy products and isoflavones, green tea, heterocyclic amines, and adolescent diet. The PubMed database was searched for all prospective studies that relate these dietary items to the incidence of breast cancer or consider gene-diet interactions. Among the prospective epidemiologic studies conducted on diet and breast cancer incidence and gene-diet interactions and breast cancer incidence, to date there is no association that is consistent, strong, and statistically significant, with the exception of alcohol intake, overweight, and weight gain. The apparent lack of association between diet and breast cancer may reflect a true absence of association between diet and breast cancer incidence or may be due to measurement error exceeding the variation in the diet studied, lack of sufficient follow-up, and focus on an age range of low susceptibility. The risk of breast cancer can be reduced by avoidance of weight gain in adulthood and limiting the consumption of alcohol.

Influences of chymase and angiotensin I-converting enzyme gene polymorphisms on gastric cancer risks in Japan

BACKGROUNDS AND AIMS

The renin-angiotensin system plays an important role in homeostasis. Angiotensin II, which is generated by chymase and angiotensin I-converting enzyme (ACE), controls blood pressure as well as angiogenesis and cell proliferation. The aim of this study was to clarify the association of the chymase gene (CMA/B) and ACE polymorphisms with susceptibility to gastric cancer and peptic ulcer.

METHODS

We assessed CMA/B A/G and ACE insertion/deletion (I/D) polymorphisms in H. pylori-positive gastric cancers (n = 119), gastric ulcers (n = 127), and duodenal ulcers (n = 105), and controls (n = 294) consisting of H. pylori-positive gastritis alone (n = 162) and H. pylori-negative subjects (n = 132) by PCR methods.

RESULTS

In CMA/B polymorphism, the age- and sex-adjusted odds ratios (OR) of A/A and A/G genotypes relative to the G/G genotype for gastric cancer risk were 7.115 (95% confidence interval, 1.818-27.845) and 1.956 (95% confidence interval, 1.137-3.366), respectively. There was an increased risk for gastric ulcer in the A/A genotype (OR, 3.450; 1.086-10.960). However, there was no association between ACE polymorphism and susceptibility to gastric cancer and peptic ulcer. In allele combination analysis of CMA/B and ACE polymorphisms, the A/I allele combinations (CMA/B G/A or A/A and ACE I/I genotype) significantly increased the risk of gastric cancer development (OR, 4.749, 2.050-11.001) compared with the G/I allele combinations (CMA/B G/G and ACE I/I genotype).

CONCLUSIONS

The CMA/B polymorphism was associated with an increased risk for gastric cancer and gastric ulcer development. The genotyping test of the renin-angiotensin system could be useful for the screening of individuals with higher risks of gastric cancer and gastric ulcer.

Transforming-growth factor beta1 Leu10Pro polymorphism and breast cancer morbidity

TGF-beta1 has a dual role in carcinogenesis. In this gene, a leucine to proline substitution in codon 10 leads to higher circulating levels of TGF-beta1. This variant has been studied in relationship to the risk for breast cancer yielding contradicting results. We aim to unravel the relationship of this polymorphism and the risk of breast cancer. Women participating in the Rotterdam Study including 143 patients with incident breast cancer were genotyped for this polymorphism. We carried out a logistic regression and a survival analysis using age as the time variable. The logistic regression analysis showed an increased risk of breast cancer for Proline carriers (OR=1.4; 95% confidence interval (CI)=1.1-2.0) versus non-carriers. The survival analysis showed that carriers of the same allele had an increased risk of breast cancer (HR=1.4, 95% CI=1.1-2.0) against non-carriers. Our data suggest that the TGF-beta1 Leu10Pro polymorphism might play a role in breast cancer risk.

Differential roles of Angiotensinogen and Angiotensin Receptor type 1 polymorphisms in breast cancer risk

While angiotensinogen (AGT) seems to have anti proliferative properties, angiotensin II (ATII) is a potent growth factor and it mediates its actions through the angiotensin type 1 receptor (AGTR1). In the AGT gene, the M235T polymorphism has been associated with the variation in angiotensinogen levels and in the AGTR1 gene; the C573T variant is associated with different pathologies. We aimed to evaluate the relationship of these two variants and the risk of breast cancer. These polymorphisms were genotyped in 3787 women participating the Rotterdam Study. We performed a logistic regression and a disease free survival analysis by genotype. The logistic regression yielded an odds ratio of 1.4 (95% CI: 1.1-1.9) for the MM genotype carriers versus the T allele carriers. The breast cancer free survival by AGT genotype was significantly reduced in MM genotype carriers compared to non-carriers (hazard ratio (HR) = 1.5; 95% CI: 1.1-2.2). We did not find any association of the AGTR1 polymorphism and breast cancer risk or disease free survival. Our results suggest that AGT plays a role in breast cancer risk in postmenopausal women, whereas the role of AGTR1 needs further studying.

Manipulating the angiotensin system--new approaches to the treatment of solid tumours

Angiotensin II (Ang II), a main effector peptide in the renin-angiotensin system (RAS), plays a fundamental role as a vasoconstrictor in controlling cardiovascular function and renal homeostasis. Ang II also acts as a growth promoter or angiogenic factor via type 1 angiotensin II receptors (AT1Rs) in certain tumour cell lines. Recent studies have shown the activation of the local RAS in various tumour tissues, including the abundant generation of Ang II by angiotensin-converting enzyme (ACE) and the upregulation of AT1R expression. Thus, considerable attention has been paid to the role of the RAS in cancer and its blockade as a new approach to the treatment of cancer. There is increasing evidence that the Ang II-AT1R system is involved in tumour growth, angiogenesis and metastasis in experimental models, suggesting the therapeutic potential of an ACE inhibitor and AT1R blocker, both of which have been used as antihypertensive drugs. In addition, specific Ang II-degrading enzymes are expressed in tumours and play a regulatory role in cell proliferation and invasion. This review focuses on the role of the Ang II-AT1R system in solid tumours, particularly in the progression of gynaecological cancer, and presents the clinical potential of manipulating the angiotensin system as a novel and promising strategy for cancer treatment.

Association between the Polymorphism of the Angiotensin-Converting Enzyme Gene and Tumor Size of Breast Cancer in Premenopausal Patients

The association between the polymorphism of the angiotensin-converting enzyme (ACE) gene and breast cancer risk has been extensively studied, however, the studies about the prognostic factors and ACE gene polymorphism are limited in number. Our aims were to analyze the distribution of the insertion/deletion (I/D) polymorphism of the ACE gene in Turkish premenopausal patients with breast cancer, which is more aggressive than the postmenopausal counterpart, and to assess whether DD genotype is associated with poor prognostic factors. The DD genotype has been shown to be associated with the increased serum and tissue levels of ACE, compared to those in II and ID genotypes. ACE genotypes were determined by polymerase chain reaction in 44 Turkish premenopausal patients with breast cancer and in 46 age-matched healthy premenopausal women. ACE genotypes are distributed in patients and control subjects as follows; DD is present in 25 (56.8%), ID in 17 (38.6%), and II in 2 (4.5%) patients, and DD in 28 (60.9%), ID in 12 (26.1%), and II in 6 (13.0%) healthy subjects, respectively. D and I alleles were found in 76.1% and 23.9% of the patients, while 73.9% and 26.1% in healthy subjects, respectively. In breast cancer patients, no significant association was observed between the ACE genotypes and poor prognostic factors, such as negative hormone receptor status, histological grade, lymph node involvement, higher number of lymph node metastases, and c-erb B2 overexpression, except that tumor size greater than 2 cm is associated with DD genotype (p = 0.02). Thus, ACE may influence the local tumor growth of breast cancer in premenopausal patients.