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

Association between a single-nucleotide polymorphism of the angiotensin-converting enzyme gene and susceptibility to systemic lupus erythematosus in the Hainanese population of China

The angiotensin-converting enzyme (ACE) gene plays a significant role in regulating immune responses and inflammatory processes, thus impacting the susceptibility to systemic lupus erythematosus (SLE). Understanding how single-nucleotide polymorphisms (SNPs) within the ACE gene contribute to the genetic susceptibility to SLE is essential for comprehending the disease's aetiology. Therefore, exploring this relationship in the Hainan region of China is crucial for gaining insights into the pathogenesis of SLE. This study comprised 428 participants, including 214 SLE patients and 214 healthy controls. Clinical data were gathered, and blood samples were collected. Genotyping of three SNPs (rs4459609, rs4309, rs1987692) within the ACE gene was performed using SNaPshot technology. The frequencies of alleles and genotypes of these three SNPs were compared between the SLE and control groups. Combining different genetic models and haplotype analysis, the correlation between ACE gene polymorphisms and SLE was investigated. Both study groups exhibited conformity with the Hardy-Weinberg genetic equilibrium (p > .05). Significant differences were observed in the genotype frequency distributions of ACE genes rs4459609, rs4309 and rs1987692 between the SLE and control groups (p = .009, .008, .032, respectively). The frequency of allele T at rs4309 was significantly higher in the SLE group than in the control group, correlating significantly with increased SLE risk (odds ratio [OR] = 1.527, 95% confidence interval [CI] = 1.147-2.035). Associations among ACE rs4459609, rs4309 and rs1987692 polymorphisms and increased susceptibility to SLE were found under co-dominant and dominant models (p < .05, with OR values and 95% CI greater than 1). Linkage disequilibrium was observed among rs4459609, rs4309 and rs1987692, and haplotype analysis revealed a significantly higher frequency of the CCA haplotype in the control group compared to the SLE group (p < .001). The ACA and ATA haplotypes showed significantly higher frequencies in the SLE group than in the control group (p = .014, p = .013, respectively). ACE gene polymorphisms are associated with the genetic susceptibility to SLE. The AC and AA genotypes at the rs4459609 locus, the TT genotype and T allele at the rs4309 locus and the AC and CC genotypes at the rs1987692 locus may serve as risk factors for the development of SLE.

The Genetic Landscape of Systemic Rheumatic Diseases: A Comprehensive Multigene-Panel Study Identifying Key Gene Polymorphisms

Systemic rheumatic diseases, including conditions such as rheumatoid arthritis, Sjögren's syndrome, systemic sclerosis, and systemic lupus erythematosus, represent a complex array of autoimmune disorders characterized by chronic inflammation and diverse clinical manifestations. This study focuses on unraveling the genetic underpinnings of these diseases by examining polymorphisms in key genes related to their pathology. Utilizing a comprehensive genetic analysis, we have documented the involvement of these genetic variations in the pathogenesis of rheumatic diseases. Our study has identified several key polymorphisms with notable implications in rheumatic diseases. Polymorphism at chr11_112020916 within the IL-18 gene was prevalent across various conditions with a potential protective effect. Concurrently, the same IL18R1 gene polymorphism located at chr2_103010912, coding for the IL-18 receptor, was observed in most rheumatic conditions, reinforcing its potential protective role. Additionally, a further polymorphism in IL18R1 at chr2_103013408 seems to have a protective influence against the rheumatic diseases under investigation. In the context of emerging genes involved in rheumatic diseases, like PARK2, a significant polymorphism at chr6_161990516 was consistently identified across different conditions, exhibiting protective characteristics in these pathological contexts. The findings underscore the complexity of the genetic landscape in rheumatic autoimmune disorders and pave the way for a deeper understanding of their etiology and the possible development of more targeted and effective therapeutic strategies.

Association between angiotensin-converting enzyme inhibitors and the risk of lung cancer: a systematic review and meta-analysis

BACKGROUND

The association between the use of angiotensin-converting enzyme inhibitors (ACEIs) and lung cancer risk remains controversial. This study evaluated the association between the use of ACEIs and lung cancer risk.

METHODS

Records from five databases were searched from inception to 26 January 2022. Clinical studies involving persons aged ≥18 years with at least one year of follow-up and reporting adverse events, including lung cancer, were recorded with separate outcome reports supplied for the ACEIs and control groups. Data were extracted independently by three authors and pooled using a random-effects model. The primary outcome was lung cancer development. Odds ratios (ORs) with 95% confidence intervals (CIs) and lung cancer-related morbidity were calculated.

RESULTS

Of 2400 records screened, 13,061,226 patients were included from seven cohort studies and four case-control studies. Pooled results showed that ACEIs use was linked to increased lung cancer risk (OR 1.19, 95% CI 1.05-1.36; P = 0.008), with high heterogeneity (I2 = 98%).

CONCLUSIONS

ACEI usage is a greater risk factor for lung carcinogenesis than angiotensin receptor blocker use, especially in Asian patients. Further randomised controlled trials are needed to confirm the causal association between the use of ACEIs and lung cancer risk.

CK2 and the Hallmarks of Cancer

Cancer is a leading cause of death worldwide. Casein kinase 2 (CK2) is commonly dysregulated in cancer, impacting diverse molecular pathways. CK2 is a highly conserved serine/threonine kinase, constitutively active and ubiquitously expressed in eukaryotes. With over 500 known substrates and being estimated to be responsible for up to 10% of the human phosphoproteome, it is of significant importance. A broad spectrum of diverse types of cancer cells has been already shown to rely on disturbed CK2 levels for their survival. The hallmarks of cancer provide a rationale for understanding cancer's common traits. They constitute the maintenance of proliferative signaling, evasion of growth suppressors, resisting cell death, enabling of replicative immortality, induction of angiogenesis, the activation of invasion and metastasis, as well as avoidance of immune destruction and dysregulation of cellular energetics. In this work, we have compiled evidence from the literature suggesting that CK2 modulates all hallmarks of cancer, thereby promoting oncogenesis and operating as a cancer driver by creating a cellular environment favorable to neoplasia.

Impact of renin-angiotensin system inhibitors on outcomes in patients with metastatic renal cell carcinoma treated with immune-checkpoint inhibitors

BACKGROUND

Renin-angiotensin system inhibitors (RASi) have been shown to improve outcomes in studies of multiple malignancies by effects on the tumor microenvironment to enhance the immune repertoire and improve drug delivery. Repurposing RASi to treat metastatic renal cell carcinoma (mRCC) in combination with immune-checkpoint inhibitors (ICI) may improve survival coupled with tolerability and cost efficacy. We evaluated the impact of RASi on outcomes in mRCC patients receiving ICI.

METHODS

This multicenter, retrospective cohort study included mRCC patients treated with ICI with or without RASi. The patients from Dana-Farber Cancer Institute (DFCI) were used as a discovery cohort, and the patients from University of California San Diego (UCSD) were used for validation. Receipt of an ICI (PD1/L1 and/or CTLA-4 inhibitors) was required. RASi use was defined as receipt of a RASi at baseline and for a minimum of 30 days after ICI initiation. For both the discovery and validation cohorts, the primary outcome assessed was overall survival (OS) and the secondary endpoints were time-to-treatment failure (TTF), and objective response rate (ORR).

RESULTS

Overall, 229 patients who received an ICI were included: 100 patients from DFCI and 129 patients from UCSD. Concomitant RASi were administered in 30 patients (30%) in the DFCI cohort and 59 (45%) in the UCSD cohort. Median age at ICI initiation was 62.5 years in both cohorts. Median follow-up was 3.8 [IQR 3-5.3] years in the DFCI cohort, and 2.3 [IQR 1.4-3.6] years in the UCSD cohort. In the DFCI cohort, RASi was significantly associated with longer OS (adjusted-HR 0.35 [95% CI, 0.17-0.70], P = .003) and TTF (adjusted-HR 0.57 [0.36-0.92], P = .02). In the validation cohort, RASi was associated with TTF (adjusted HR, 0.60 [0.39-0.92], P = .02) and not statistically associated with OS (adjusted-HR 0.60 [0.34-1.06], P = .07). The propensity analysis, matching 83 patients from both cohorts receiving RASi while on ICI with 83 who did not, showed that RASi significantly improved OS (HR 0.59 [0.37-0.95], P = .03) and TTF (HR 0.60 [0.43-0.85], P = .0034).

CONCLUSIONS

RASi was associated with improved OS and TTF in mRCC patients receiving ICI. This provides a rationale for prospective randomized studies combining ICI and RASi in mRCC patients.

Impact of renin-angiotensin system inhibitors on the survival of patients with rectal cancer

Background

Renin-angiotensin system inhibitors (RASIs) are widely used in the treatment of hypertension. However, their impact on the outcome of the combined treatment of rectal cancer is poorly understood. The aim of this study was to assess the effect of RASIs on the survival of rectal cancer patients with associated hypertension after neoadjuvant treatment and radical resection.

Methods

Between 2008 and 2016, 242 radical (R0) rectal resections for cancer were performed after neoadjuvant treatment in patients with associated hypertension. At the time of treatment, 158 patients were on RASIs, including 35 angiotensin-receptor antagonists (ARB) users and 123 angiotensin-converting enzyme inhibitors (ACEI) users. Eighty-four patients were on drugs other than RASIs (non-RASI users). The survival analysis was performed using the Kaplan–Meier estimator with the log-rank test and the Cox proportional hazards model.

Results

The log-rank test showed a significantly worse overall survival (OS) in the group of ACEI users compared to ARB users (p = 0.009) and non-RASI users (p = 0.013). Disease-free survival (DFS) was better in the group of ARB users compared to ACEI users. However, the difference was not statistically significant (p = 0.064). The Multivariate Cox analysis showed a significant beneficial effect of ARBs on OS (HR: 0.326, 95% CI: 0.147–0.724, p = 0.006) and ARBs on DFS (HR: 0.339, 95% CI: 0.135–0.850, p = 0.021) compared to ACEIs. Other factors affecting OS included age (HR: 1.044, 95% CI: 1.016–1.073, p = 0.002), regional lymph node metastasis (ypN +) (HR: 2.157, 95% CI: 1.395–3.334, p = 0.001) and perineural invasion (PNI) (HR: 3.864, 95% CI: 1.799–8.301, p = 0.001). Additional factors affecting DFS included ypN + (HR: 2.310, 95% CI: 1.374–3.883, p = 0.002) and PNI (HR: 4.351, 95% CI: 1.584–11.954, p = 0.004).

Conclusions

The use of ARBs instead of ACEIs may improve the outcome of the combined therapy for rectal cancer patients with associated hypertension.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09919-0.

Anti-hypertensive medications and risk of colorectal cancer: a systematic review and meta-analysis

PURPOSE

Antihypertensive medications may impact colorectal cancer risk. We conducted a systematic review and meta-analysis of associations, with colorectal cancer risk, of five classes of antihypertensive medications: angiotensin-converting enzyme inhibitors (ACEIs), angiotensin II receptor blockers (ARBs), beta-blockers (BBs), calcium channel blockers (CCBs), and diuretics.

METHODS

A systematic search was conducted in MEDLINE, Embase, Web of Science, and the Cochrane library to identify relevant studies evaluating associations of ACEIs, ARBs, BBs, CCBs, and diuretics with colorectal cancer risk. Meta-analytic risk ratios (RRs) and corresponding 95% confidence intervals (95% CIs) were calculated using the inverse variance method.

RESULTS

No overall significant associations with colorectal cancer risk were observed; ACEIs (5 studies) RR 1.05, 95% CI 0.91-1.23, ARBs (5 studies) RR 0.94, 95% CI 0.80-1.11, BBs (4 studies) RR 1.00, 95% CI 0.92-1.08, CCBs (4 studies) RR 1.02, 95% CI 0.88-1.18, and diuretics (6 studies) RR 1.02, 95% CI 0.90-1.17. There was considerable heterogeneity across studies, partly explained by differences in study design and location. When stratified by study location, there was significantly reduced colorectal cancer risk for ARB use in Asian populations (2 studies, RR 0.69, 95% CI 0.58-0.83).

CONCLUSION

No significant colorectal cancer risk with ACEIs, BBs, CCBs, or diuretics was observed. ARB use may be associated with decreased risk of colorectal cancer in Asian populations, although additional studies in diverse populations are needed to confirm associations and help understand possible reasons for geographical differences.

Risk factors for long-term survival in patients with ypN+ M0 rectal cancer after radical anterior resection

Background

Regional lymph node metastases are the main adverse prognostic factor in patients with rectal cancer without distant metastases. There are discrepancies, however, regarding additional risk factors in the group of ypN + M0 patients. The purpose of the study was to assess clinical and pathological factors affecting long-term oncological outcomes in the group of ypN + M0 patients after radical rectal anterior resection.

Methods

112 patients with ypN + M0 rectal cancer after neoadjuvant therapy and radical anterior resection were subject to a retrospective analysis. The effect of potential factors on survival was assessed with the use of Kaplan–Meier curves together with a log-rank test and multiple factor Cox proportional hazards model.

Results

In the multiple factor Cox analysis, adverse factors affecting disease-free survival (DFS) were: the use of angiotensin-converting enzyme inhibitors (ACEIs) (hazard ratio HR: 3.11, 95% CI 1.01–9.56, p = 0.047), presence of perineural invasion (HR: 7.27, 95% CI 2.74–19.3, p < 0.001) and occurrence of postoperative complications (HR: 6.79, 95% CI 2.09–22.11, p = 0.001), while a positive factor was the negative lymph node (NLN) count > 7 (HR: 0.33, 95% CI 0.12–0.88, p = 0.026). In the disease-specific survival (DSS) analysis, an adverse factor was the use of ACEIs (HR: 4.275, 95% CI 1.44–12.694, p = 0.009), while a positive effect was caused by NLN > 5 (HR: 0.22, 95% CI 0.082–0.586, p = 0.002).

Conclusions

The use of ACEIs may have a negative effect on long-term treatment outcomes in patients with ypN + M0 rectal cancer. In this group of patients, the NLN count seems to be an important prognostic factor, as well.

Genetically proxied therapeutic inhibition of antihypertensive drug targets and risk of common cancers: A mendelian randomization analysis

BACKGROUND

Epidemiological studies have reported conflicting findings on the potential adverse effects of long-term antihypertensive medication use on cancer risk. Naturally occurring variation in genes encoding antihypertensive drug targets can be used as proxies for these targets to examine the effect of their long-term therapeutic inhibition on disease outcomes.

METHODS AND FINDINGS

We performed a mendelian randomization analysis to examine the association between genetically proxied inhibition of 3 antihypertensive drug targets and risk of 4 common cancers (breast, colorectal, lung, and prostate). Single-nucleotide polymorphisms (SNPs) in ACE, ADRB1, and SLC12A3 associated (P < 5.0 × 10-8) with systolic blood pressure (SBP) in genome-wide association studies (GWAS) were used to proxy inhibition of angiotensin-converting enzyme (ACE), β-1 adrenergic receptor (ADRB1), and sodium-chloride symporter (NCC), respectively. Summary genetic association estimates for these SNPs were obtained from GWAS consortia for the following cancers: breast (122,977 cases, 105,974 controls), colorectal (58,221 cases, 67,694 controls), lung (29,266 cases, 56,450 controls), and prostate (79,148 cases, 61,106 controls). Replication analyses were performed in the FinnGen consortium (1,573 colorectal cancer cases, 120,006 controls). Cancer GWAS and FinnGen consortia data were restricted to individuals of European ancestry. Inverse-variance weighted random-effects models were used to examine associations between genetically proxied inhibition of these drug targets and risk of cancer. Multivariable mendelian randomization and colocalization analyses were employed to examine robustness of findings to violations of mendelian randomization assumptions. Genetically proxied ACE inhibition equivalent to a 1-mm Hg reduction in SBP was associated with increased odds of colorectal cancer (odds ratio (OR) 1.13, 95% CI 1.06 to 1.22; P = 3.6 × 10-4). This finding was replicated in the FinnGen consortium (OR 1.40, 95% CI 1.02 to 1.92; P = 0.035). There was little evidence of association of genetically proxied ACE inhibition with risk of breast cancer (OR 0.98, 95% CI 0.94 to 1.02, P = 0.35), lung cancer (OR 1.01, 95% CI 0.92 to 1.10; P = 0.93), or prostate cancer (OR 1.06, 95% CI 0.99 to 1.13; P = 0.08). Genetically proxied inhibition of ADRB1 and NCC were not associated with risk of these cancers. The primary limitations of this analysis include the modest statistical power for analyses of drug targets in relation to some less common histological subtypes of cancers examined and the restriction of the majority of analyses to participants of European ancestry.

CONCLUSIONS

In this study, we observed that genetically proxied long-term ACE inhibition was associated with an increased risk of colorectal cancer, warranting comprehensive evaluation of the safety profiles of ACE inhibitors in clinical trials with adequate follow-up. There was little evidence to support associations across other drug target-cancer risk analyses, consistent with findings from short-term randomized controlled trials for these medications.

Tumor microenvironment-responsive dynamic inorganic nanoassemblies for cancer imaging and treatment

Dynamic inorganic nanoassemblies (DINAs) have emerged as smart nanomedicine platforms with promising potential for bioimaging and targeted drug delivery. In this review, we keep abreast of the advances in development of tumor microenvironment (TME)-responsive DINAs to meet the challenges associated with precise cancer therapy. TME-responsive DINAs are designed to achieve precise switches of structures/functions in response to TME-specific stimuli including reactive oxygen species (ROS), reduced pH and hypoxia, so as to enhance the tumor accumulation of nanoassemblies, overcome the biological barriers during intratumoral penentration of therapeutics, and achieve tumor-specific imaging and therapy. This progress report will summarize various types of recently reported smart DINAs for TME-responsive tumor imaging and therapy. Their future development towards potential clinical translation will also be discussed.

Renin-Angiotensin System in the Tumor Microenvironment

For enhancing the antitumor effects of current immunotherapies including immune-checkpoint blockade, it is important to reverse cancer-induced immunosuppression. The renin-angiotensin system (RAS) controls systemic body fluid circulation; however, the presence of a local RAS in tumors has been reported. Furthermore, the local RAS in tumors influences various immune and interstitial cells and affects tumor immune response. RAS stimulation through the angiotensin II type 1 receptor has been reported to inhibit tumor immune response. Therefore, RAS inhibitors and combined treatment with immunotherapy are expected in the future. In this chapter, we provide a background on the RAS and describe the tumor environment with regard to the RAS and tumor immune response.

Angiotensin-converting enzyme (ACE) inhibitor prescription affects non-small-cell lung cancer (NSCLC) patients response to PD-1/PD-L1 immune checkpoint blockers

Angiotensin-converting enzyme (ACE) inhibitors are frequently used to treat hypertension and congestive heart failure. Preclinical data show that ACE plays a role on both innate and adaptive immune responses. Since interactions between ACE inhibitors and immune checkpoint inhibitors (ICIs) have not been reported, the aim of this study is to investigate the influence of ACE inhibitors on non-small cell lung cancer (NSCLC) patients treated with programmed cell death-1 (PD-1)/programmed cell death-ligand 1 (PD-L1) inhibitors. We conducted a retrospective cohort analysis of NSCLC patients treated with PD-1/PD-L1 inhibitors. Clinical and co-medication data as well as tumor biopsies were collected. Groups were defined according to patients' co-medications at the time of ICI initiation. Among the 178 patients included, 22 (13.1%) received ACE inhibitors. While baseline characteristics were similar in both groups, ACE inhibitors group had a shorter median PFS (Progression-Free Survival) compared to the control group: 1.97 vs. 2.56 months, p = .01 (HR = 1.8 CI95% 1.1-2.8). Using CIBERSORT, RNA sequencing suggested that tumors from the ACE inhibitors group had less M1 macrophages, activated mast cells, NK cells and memory activated T cells, thus suggesting an immunosuppressed state. In vitro, the ACE inhibitor, captopril, induced M2 marker at the cell surface of monocytes engaged into M1 differentiation. Thus, ACE inhibitors prescription concomitant to PD-1/PD-L1 inhibitors treatment seems to be associated with impaired outcome and with a tumor immunosuppressed state in patients with advanced NSCLC. These results should be validated in larger prospective cohorts.

The systemic inflammatory response as a source of biomarkers and therapeutic targets in hepatocellular carcinoma

The pathogenesis of hepatocellular carcinoma (HCC) strongly relates to inflammation, with chronic up-regulation of pro-inflammatory mediators standing as a potential unifying mechanism that underscores the origin and progression of HCC independent of aetiology. Activation of the diverse pro-inflammatory mediators either within the tumour or its microenvironment is part of an active cross-talk between the progressive HCC and the host, which is known to influence clinical outcomes including recurrence after radical treatments and long-term survival. A number of clinical biomarkers to measure the severity of cancer-related inflammation are now available, most of which emerge from routine blood parameters including neutrophil, lymphocyte, platelet counts, as well as albuminaemia and C-reactive protein levels. In this review, we summarise the body of evidence supporting the biologic qualification of inflammation-based scores in HCC and review their potential in facilitating the prognostic assessment and treatment allocation in the individual patient. We also discuss the evidence to suggest modulation of tumour-promoting inflammation may act as a source of novel therapeutic strategies in liver cancer.

Is preoperative chemoradiation in rectal cancer patients modulated by ACE inhibitors? Results from the Dutch Cancer Registry

BACKGROUND AND PURPOSE

The aim of this study was to assess the effect of angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) on tumor response to preoperative chemoradiation for rectal cancer.

MATERIALS AND METHODS

Data on patients who received chemoradiation prior to surgery for rectal cancer between 2010 and 2015 were retrieved from linkage between the PHARMO Database Network, Dutch Pathology Registry and Netherlands Cancer Registry. Pathological complete response rates (pCR) were compared between patients who did or did not use ACEIs/ARBs during treatment. Multivariable analysis was performed using logistic regression.

RESULTS

Out of 345 patients, 92 patients (26.7%) used ACEIs/ARBs during treatment. Median age was 65 years (range 30-85). Older and male patients were more likely to use ACEIs/ARBs. pCR (ypT0N0) was observed in 17.4% of patients using ACEIs/ARBs compared to 14.6% of patients who did not use ACEIs/ARBs (p = 0.595). A good response (ypT0-1N0) was observed in 21.7% of ACEIs/ARBs patients vs. 19.4% of patients who did not use ACEIs/ARBs (p = 0.724). Multivariable analysis, taking into account background variables and co-medication, showed increased pCR in patients using beta-blockers (odds ratio 2.3, 95% confidence interval 1.0-5.4).

CONCLUSION

In this retrospective cohort, the use of ACEIs/ARBs was not associated with tumor response to preoperative chemoradiation in rectal cancer patients. Thereby, the suggested potentiating effect of ACEIS/ARBs could not be confirmed in our study. Further research could be directed to investigate a possible benefit of beta-blockers or other anti-hypertensive drugs.

Renin-angiotensin inhibitors reprogram tumor immune microenvironment: A comprehensive view of the influences on anti-tumor immunity

Renin-angiotensin system inhibitors (RASi) have shown potential anti-tumor effects that may have a significant impact in cancer therapy. The components of the renin-angiotensin system (RAS) including both, conventional and alternative axis, appear to have contradictory effects on tumor biology. The mechanisms by which RASi impair tumor growth extend beyond their function of modulating tumor vasculature. The major focus of this review is to analyze other mechanisms by which RASi reprogram the tumor immune microenvironment. These involve impairing hypoxia and acidosis within the tumor stroma, regulating inflammatory signaling pathways and oxidative stress, modulating the function of the non-cellular components and immune cells, and regulating the cross-talk between kalli krein kinin system and RAS.

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.

Renin angiotensin system and its role in biomarkers and treatment in gliomas

Gliomas are the most common primary intrinsic tumor in the brain and are classified as low- or high-grade according to the World Health Organization (WHO). Patients with high-grade gliomas (HGG) who undergo surgical resection with adjuvant therapy have a mean overall survival of 15 months and 100% recurrence. The renin-angiotensin system (RAS), the primary regulator of cardiovascular circulation, exhibits local action and works as a paracrine system. In the context of this local regulation, the expression of RAS peptides and receptors has been detected in different kinds of tumors, including gliomas. The dysregulation of RAS components plays a significant role in the proliferation, angiogenesis, and invasion of these tumors, and therefore in their outcomes. The study and potential application of RAS peptides and receptors as biomarkers in gliomas could bring advantages against the limitations of current tumoral markers and should be considered in the future. The targeting of RAS components by RAS blockers has shown potential of being protective against cancer and improving immunotherapy. In gliomas, RAS blockers have shown a broad spectrum for beneficial effects and are being considered for use in treatment protocols. This review aims to summarize the background behind how RAS plays a role in gliomagenesis and explore the evidence that could lead to their use as biomarkers and treatment adjuvants.

Angiotensin receptor blockade: a novel approach for symptomatic radiation necrosis after stereotactic radiosurgery

Preclinical evidence suggests angiotensin blockade therapy (ABT) decreases late radiation toxicities. This study aims to investigate the association between ABT and symptomatic radiation necrosis (SRN) following stereotactic radiosurgery (SRS). Resected brain metastases (rBM) and arteriovenous malformation (AVM) patients treated with SRS from 2002 to 2015 were identified. Patients in the ABT cohort were on therapy during SRS and at 1-month follow up. Kaplan Meier method and cumulative incidence model were used to analyze overall survival (OS) and intracranial outcomes. 228 consecutive patients were treated with SRS: 111 with rBM and 117 with AVM. Overall, 51 (22.4%) patients were in the ABT group: 32 (28.8%) in the rBM and 19 (16.2%) in AVM cohorts. Baseline characteristics were similar, except for higher Graded Prognostic Analysis (3-4) in the rBM (ABT: 25.0% vs. non-ABT: 49.0%, p = 0.033) and median age in the AVM (ABT: 51.4 vs. non-ABT: 35.4, p < 0.001) cohorts. In both populations, OS and intracranial efficacy (rBM-local control; AVM-obliteration rates) were statistically similar between the cohorts. ABT was associated with lower 1-year SRN rates in both populations: rBM, 3.1 versus 25.3% (p = 0.003); AVM, 6.7 vs. 14.6% (p = 0.063). On multivariate analysis, ABT was a significant predictive factor for rBM (HR: 0.17; 95% CI 0.03-0.88, p = 0.035), but did not reach statistical significance for AVM (HR: 0.36; 95% CI 0.09-1.52, p = 0.165). ABT use appears to be associated with a reduced risk of SRN following SRS, without detriment to OS or intracranial efficacy. A prospective trial to validate these findings is warranted.

Use of inhibitors of the renin-angiotensin system is associated with longer survival in patients with hepatocellular carcinoma

BACKGROUND

Inhibition of the renin-angiotensin system (RAS) was associated with longer survival in patients with different solid malignancies.

OBJECTIVE

The objective of this study was to investigate the effect of RAS inhibitor (RASi) treatment (angiotensin-converting enzyme inhibitors or angiotensin-II-receptor blockers) on survival of patients with hepatocellular carcinoma (HCC).

METHODS

Patients diagnosed with HCC and Child-Pugh A between 1992 and 2013 who received sorafenib, experimental therapy, or best supportive care were eligible for the Vienna cohort. The Mainz cohort included patients with HCC and Child-Pugh A who received sorafenib treatment between 2007 and 2016. The association between RASi and overall survival (OS) was evaluated in univariate and multivariate analyses.

RESULTS

In the Vienna cohort, 43 of 156 patients received RASi for hypertension. RASi treatment was associated with longer OS (11.9 vs. 6.8 months (mo); p = 0.014) and remained a significant prognostic factor upon multivariate analysis (HR = 0.6; 95% CI 0.4-0.9; p = 0.011). In subgroup analysis, patients treated with sorafenib plus RASi had better median OS (19.5 mo) compared to those treated with either sorafenib (10.9 mo) or RASi (9.7 mo) alone (p = 0.043). The beneficial effect of RASi on survival was confirmed in the Mainz cohort (n = 76).

CONCLUSION

RAS inhibition is associated with longer survival in HCC patients with Child-Pugh class A.

Increased tumor response to neoadjuvant therapy among rectal cancer patients taking angiotensin-converting enzyme inhibitors or angiotensin receptor blockers

BACKGROUND

Angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) are commonly used antihypertensive medications that have been reported to affect aberrant angiogenesis and the dysregulated inflammatory response. Because of such mechanisms, it was hypothesized that these medications might affect the tumor response to neoadjuvant radiation in patients with rectal cancer.

METHODS

One hundred fifteen patients who were treated with neoadjuvant radiation at the University of Wisconsin (UW) between 1999 and 2012 were identified. Univariate analyses were performed with anonymized patient data. In a second independent data set, 186 patients with rectal cancer who were treated with neoadjuvant radiation at the Queen's Medical Center of the University of Hawaii (UH) between 1995 and 2010 were identified. These data were independently analyzed as before. Multivariate analyses were performed with aggregate data.

RESULTS

Among patients taking ACEIs/ARBs in the UW data set, a significant 3-fold increase in the rate of pathologic complete response (pCR) to neoadjuvant therapy (52% vs 17%, P = .001) was observed. This finding was confirmed in the UH data set, in which a significant 2-fold-increased pCR rate (24% vs 12%, P = .03) was observed. Identified patient and treatment characteristics were otherwise balanced between patients taking and not taking ACEIs/ARBs. No significant effect was observed on pCR rates with other medications, including statins, metformin, and aspirin. Multivariate analyses of aggregate data identified ACEI/ARB use as a strong predictor of pCR (odds ratio, 4.02; 95% confidence interval, 2.06-7.82; P < .001).

CONCLUSIONS

The incidental use of ACEIs/ARBs among patients with rectal cancer is associated with a significantly increased rate of pCR after neoadjuvant treatment. Cancer 2016;122:2487-95. © 2016 American Cancer Society.

[Angiotensin converting enzyme: the antigenic properties of the domain, role in Alzheimer's disease and tumor progression]

Angiotensin converting enzyme (ACE, EC 3.4.15.1) was discovered and characterized in the Laboratory of biochemistry and chemical pathology of proteins under the direction of academician V.N. Orekhovich, where its physiological function, associated with a key role in the regulation of the renin-angiotensin (RAS) and the kallikrein-kinin systems that control blood flow in the body and homeostasis was first deciphered. We carried out a search for structural differences between the two highly homologous domains (N- and C-domains) of somatic ACE (sACE); it was based on a comparative analysis of antigenic determinants (or B-epitopes) of both domains. The revealed epitopes were classified with variable and conserved regions and functionally important sites of the molecule ACE. Essential difference was demonstrated between locations of the epitopes in the N- and C-domains. These data indicate the existence of structural differences between the domains of sACE. We studied the role of the domains of ACE in the metabolism of human amyloid beta peptide (Ab) - the main component of senile plaques, found in the brains of patients with Alzheimer's disease (AD). Our results demonstrated that only N-domain ACE cleaved the Ab between residues R5-H6, while, the C-domain of ACE failed to hydrolyze this region. In addition, the effect of post-translational modifications of Ab on its hydrolysis by the ACE was investigated. We show that isomerization of residue D7, a common non-enzymatic age-related modification found in AD-associated species, does not reduce the affinity of the peptide to the N-domain of ACE, and conversely, it increases. According to our data, the role of ACE in the metabolism of Ab becomes more significant in the development of AD. RAS is involved in malignant transformation and tumor progression. RAS components, including ACE and angiotensin II receptors type 1 (AT1R) are expressed in various human tumors. We found a significant increase in the level of ACE activity in the tumor tissue of squamous cell carcinoma of the cervix. In our viewpoint, the increase in ACE activity may be a marker of poor clinical prognosis.

A review of clinical studies on angiotensin II receptor blockers and risk of cancer

Angiotensin II receptor blockers (ARBs) are one of the most frequently used antihypertensive drugs with good tolerability and are indicated for treatment of many cardiovascular morbidity. Findings from clinical studies conducted in the past decade, suggest a possible relationship between some ARB-active substances, and certain malignancies cannot be excluded. Despite a lack of agreement, clinical results do not rule out the possibility that type 2 angiotensin II receptor stimulation during ARB therapy may also have unfavorable consequences, such as the development of certain malignancies. However, according to the current official position of FDA, the cardiovascular benefits of ARB therapy far outweigh the risks. Based on the limited information available, this review aims to provide medical practitioners with a clearer view on the balance of the benefits and risks of ARBs.

Modulation of angiogenesis by thyroid hormone and hormone analogues: implications for cancer management

Acting via a cell surface receptor on integrin αvβ3, thyroid hormone is pro-angiogenic. Nongenomic mechanisms of actions of the hormone and hormone analogues at αvβ3 include modulation of activities of multiple vascular growth factor receptors and their ligands (vascular endothelial growth factor, basic fibroblast growth factor, platelet-derived growth factor, epidermal growth factor), as well as of angiogenic chemokines (CX3 family). Thyroid hormone also may increase activity of small molecules that support neovascularization (bradykinin, angiotensin II) and stimulate endothelial cell motility. Therapeutic angio-inhibition in the setting of cancer may be opposed by endogenous thyroid hormone, particularly when a single vascular growth factor is the treatment target. This may be a particular issue in management of aggressive or recurrent tumors. It is desirable to have access to chemotherapies that affect multiple steps in angiogenesis and to examine as alternatives in aggressive cancers the induction of subclinical hypothyroidism or use of antagonists of the αvβ3 thyroid hormone receptor that are under development.

Circulating proteolytic products of carboxypeptidase N for early detection of breast cancer

BACKGROUND

Carboxypeptidase N (CPN) is important in regulating vasoactive peptide hormones, growth factors, and cytokines by specifically cleaving their C-terminal basic residues. We investigated whether circulating peptides specifically cleaved by CPN in the tumor microenvironment can be stage-specific indicators of breast cancer.

METHODS

CPN activity was measured using an ex vivo peptide cleavage assay by incubating synthesized C3f peptide (His6-C3f_S1304-R1320-His6) in interstitial fluids of breast tumors and adjacent normal breast tissues in mice with orthotopic implantation of the human cell line MDA-MB-231. The nature and extent of peptide cleavage by CPN was investigated by fragment profiling using nanopore fractionation and mass spectrometry. The fragment profiles in interstitial fluid correlated with concentrations of CPN-catalyzed peptides in blood samples taken from the tumor-bearing mice, healthy women, and breast cancer patients. CPN expression in the same set of samples was further examined by immunohistochemistry and immunoblotting.

RESULTS

We showed that generation of C3f_R1310-L1319 specifically correlated with the CPN expression level. In both the mouse and clinical patient samples, CPN was clearly increased in tumor tissues compared with normal breast tissue, whereas corresponding CPN abundance in blood remained constant. Concentrations of 6 CPN-catalyzed peptides predominantly increased in sera taken from the mice (n = 8) at 2 weeks after orthotopic implantation. Six homologous peptides displayed significantly higher expression in the patients' plasma as early as the first pathologic stage of breast cancer.

CONCLUSIONS

Circulating CPN-catalyzed peptide concentrations reflect the CPN activity in tumors. These biomarkers show strong potential for the noninvasive and early diagnosis of breast cancer.