Lack of any association between insertion/deletion (I/D) polymorphisms in the angiotensin-converting enzyme gene and digestive system cancer risk: a meta-analysis

Integrated bioinformatics analysis of miRNA expression in osteosarcoma

The expression of miRNA influencing the pathogenesis of OS have been reported previously, however, different samples selection and sequencing platforms made obvious differences in miRNA expression analysis. We aim to identify reliable prognostic and treatment biomarkers for OS by systematic analysis of miRNAs expression data sets from biased data set. Seven miRNA data sets were selected from corresponding articles. Collectively, two miRNAs, hsa-miR-19-3p and hsa-miR106b-3p, and transcription factor SIX3 were identified and may be reliable markers for prognostic and treatment of osteosarcoma.

The relationship between angiotensin-converting enzyme gene insertion/deletion polymorphism and digestive cancer risk: Insights from a meta-analysis

BACKGROUND AND OBJECTIVE

The gene encoding angiotensin-converting enzyme (ACE) has been implicated in the development of several malignancies. We aimed to meta-analyze the association of ACE gene insertion/deletion (I/D) polymorphism with digestive cancer risk and seek possible sources of between-study heterogeneity.

METHODS

Two authors independently assessed eligibility of each retrieved publication and gathered relevant data. Risk estimates were expressed as odds ratio (OR) and 95% confidence interval (CI).

RESULTS

Sixteen publications were qualified for analysis, involving 2903 digestive cancer cases and 10,833 controls. Overall analyses failed to show any significance for digestive cancer risk. There was moderate heterogeneity and lower publication bias for overall comparisons. In subgroup analyses, ACE gene II genotype was associated with a 15% reduced risk (OR=0.85, 95% CI: 0.57-1.27, p=0.434) for gastric cancer, but a 16% increased risk (OR=1.16, 95% CI: 0.89-1.52, p=0.273) for colorectal cancer. By source of controls, the I allele appeared to be a protective factor against digestive cancer in population-based studies (OR=0.87, 95% CI: 0.75-1.00, p=0.055) but a risk-conferring factor in hospital-based studies (OR=1.17, 95% CI: 1.01-1.35, p=0.033).

CONCLUSION

Our findings suggested that ACE gene I allele might be a protective factor against gastric cancer, necessitating further confirmation in large, population-based studies.

Survivin and angiotensin-converting enzyme polymorphisms with risk of colorectal cancer: a systematic review and meta-analysis

Background

Colorectal cancer (CRC) is the most common cause of cancer death worldwide. Numerous studies have identified the roles of survivin −31 G/C and angiotensin-converting enzyme insertion/deletion (ACE I/D) polymorphisms in CRC risk; however, the results remain inconclusive. This study was to investigate associations between these two polymorphisms and CRC susceptibility.

Methods

A comprehensive literature search was conducted to collect relevant case–control studies published between 2000 and 2014. The extracted data were statistically analyzed, and the odds ratios (ORs) with 95% confidence intervals (CIs) were employed to estimate the strength of association.

Results

A total of 11 studies were included in the meta-analysis. For survivin G/C polymorphism, six articles reported 1,840 cases and 1,804 controls. Overall, we found the frequency of C allele is higher in CRC cases than that in the healthy controls (57.2% vs. 48.0%), and C allele significantly increased the risk of CRC compared to G allele in allele model (OR = 1.46, 95% CI = 1.33–1.60, P < 0.00001). This association was also found in other genetic models (P < 0.00001). Stratified analysis by ethnicity showed significant association in each genetic model among the Asian population. For ACE I/D polymorphism, five studies included 758 cases and 6,755 controls. No significant association was found in any genetic models.

Conclusions

Our results showed that survivin −31 G/C polymorphism might contribute to risk of CRC, especially in the Asian populations. However, the ACE I/D polymorphism is not a genetic factor concerning the risk for CRC. More studies with larger sample sizes are required in the future.

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.