No association between ACE polymorphism and risk of nasopharyngeal carcinoma

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

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

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

BACKGROUND

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

METHODS

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

RESULT

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

CONCLUSION

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

Pre-treatment with angiotensin-(1-7) inhibits tumor growth via autophagy by downregulating PI3K/Akt/mTOR signaling in human nasopharyngeal carcinoma xenografts

Abstract

The highest incidence of nasopharyngeal carcinoma (NPC) is in southeast China, including Taiwan. Many side effects have been observed following radiation therapy with chemotherapy; hence, exploring new treatment modalities for NPC is an important future direction. Angiotensin-(1–7) [Ang-(1–7)] is an endogenous heptapeptide hormone and important component of the renin–angiotensin system that acts through both the Mas receptor and AT2 receptor, exhibiting anti-proliferative and anti-angiogenic properties in cancer cells. However, the anti-cancer activity of Ang-(1–7) related to autophagy in NPC remains largely debated. The effects and signaling pathway(s) involved in the Ang-(1–7)/Mas receptor axis in NPC were investigated both in vitro and in vivo. Ang-(1–7) inhibited cell proliferation, migration, and invasion in NPC-TW01 cells. Ang-(1–7) induced autophagy by increasing the levels of the autophagy marker LC3-II and by enhancing p62 degradation via activation of the Beclin-1/Bcl-2 signaling pathway with involvement of the PI3K/Akt/mTOR and p38 pathways in vitro study. In addition, pre-treatment with Ang-(1–7) inhibited tumor growth in NPC xenografts by inducing autophagy, suggesting a correlation between PI3K/Akt/mTOR pathway inhibition and the abovementioned anti-cancer activities. However, no autophagy was observed following Ang-(1–7) post-treatment. Taken together, these data indicate that Ang-(1–7) plays a novel role in autophagy downstream signaling pathways in NPC, supporting its potential as a therapeutic agent for alleviation the incidence of NPC and preventive treatment of recurrent NPC.

Key messages

Ang-(1–7) inhibits cell proliferation, migration, and invasion by activating autophagy

Ang-(1–7)pre-treatment inhibits tumor growth via autophagy by suppressing PI3K/Akt/mTOR pathway.

Ang-(1–7) may provide a novel preventative treatment for NPC and recurrent NPC

Electronic supplementary material

The online version of this article (10.1007/s00109-018-1704-z) contains supplementary material, which is available to authorized users.

Lack of influence of the ACE1 gene I/D polymorphism on the formation and growth of benign uterine leiomyoma in Turkish patients

Uterine leiomyomas (ULM), are benign tumors of the smooth muscle cells of the myometrium. They represent a common health problem and are estimated to be present in 30-70% of clinically reproductive women. Abnormal angiogenesis and vascular-related growth factors have been suggested to be associated with ULM growth. The angiotensin-I converting enzyme (ACE) is related with several tumors. The aim of this study was to identify possible correlation between ULM and the ACE I/D polymorphism, to evaluate whether the ACE I/D polymorphism could be a marker for early diagnosis and prognosis. ACE I/D was amplified with specific primer sets recognizing genomic DNA from ULM (n=72) and control (n=83) volunteers and amplicons were separated on agarose gels. The observed genotype frequencies were in agreement with Hardy-Weinberg equilibrium (χ2=2.162, p=0.339). There was no association between allele frequencies and study groups (χ2=0.623; p=0.430 for ACE I allele, χ2=0.995; p=0.339 for ACE D allele). In addition, there were no significant differences between ACE I/D polymorphism genotype frequencies and ULM range in size and number (χ2=1.760; p=0.415 for fibroid size, χ2=0.342; p=0.843 for fibroid number). We conclude that the ACE gene I/D polymorphism is not related with the size or number of ULM fibroids in Turkish women. Thus it cannot be regarded as an early diagnostic parameter nor as a risk estimate for ULM predisposition.

An updated meta-analysis on association between angiotensin I-converting enzyme gene insertion/deletion polymorphism and cancer risk

The Alu repetitive sequence insertion/deletion (I/D, rs4646994) polymorphism in the angiotensin I-converting enzyme (ACE) gene may alter cancer susceptibility, but results of current studies are inconclusive. To derive a more precise estimation of the relationship between the ACE I/D polymorphism and cancer risk, we performed an updated meta-analysis of all eligible studies. All studies published up to July 2013 concerning the association between the ACE I/D polymorphism and cancer risk were identified by systematically searching PubMed, EMBASE, Wanfang, CNKI, and Cqvip databases. The odds ratios (ORs) with 95 % confidence intervals (CIs) were pooled using the fixed/random-effects model in Review Manager 5.1 and STATA 12.0. A total of 46 case-control studies including 7,025 cases and 34,911 controls were identified and evaluated. Overall, we did not observe a direct association between the ACE I/D polymorphism and general cancer risk (DD + DI vs. II OR = 0.95, 95 %CI = 0.84-1.07, P = 0.40). In the subgroup analysis by cancer type, a significant increased susceptibility of prostate cancer was found for variant homozygotes (DD vs. II + ID OR = 2.15, 95 %CI = 1.01-4.55, P = 0.05). Additionally, no significant association was observed in other subgroup analyses according to ethnicity, control source, sample size and quality control of genotyping. In summary, our results suggested that the ACE I/D polymorphism might not be a common risk factor for overall cancer susceptibility, but might contribute to the susceptibility of prostate cancer. More studies with larger sample sizes are required in the future.

Genetic predisposition factors and nasopharyngeal carcinoma risk: a review of epidemiological association studies, 2000-2011: Rosetta Stone for NPC: genetics, viral infection, and other environmental factors

While infection with Epstein-Barr virus (EBV) is known to be an essential risk factor for the development of nasopharyngeal carcinoma (NPC), other co-factors including genetic factors are thought to play an important role. In this review, we summarize association studies conducted over the past decade to evaluate the role of genetic polymorphisms in NPC development. A review of the literature identified close to 100 studies, including 3 genome-wide association studies (GWAS), since 2000 that evaluated genetic polymorphisms and NPC risk in at least 100 NPC cases and 100 controls. Consistent evidence for associations were reported for a handful of genes, including immune-related HLA Class I genes, DNA repair gene RAD51L1, cell cycle control genes MDM2 and TP53, and cell adhesion/migration gene MMP2. However, for most of the genes evaluated, there was no effort to replicate findings and studies were largely modest in size, typically consisting of no more than a few hundred cases and controls. The small size of most studies, and the lack of attempts at replication have limited progress in understanding the genetics of NPC. Moving forward, if we are to advance our understanding of genetic factors involved in the development of NPC, and of the impact of gene-gene and gene-environment interations in the development of this disease, consortial efforts that pool across multiple, well-designed and coordinated efforts will most likely be required.