IL-17A (-197G/A) and IL-17F (7488T/C) gene polymorphisms and cancer risk in Asian population: a meta-analysis

Cumulative evidence for associations between genetic variants in interleukin 17 family gene and risk of human diseases

Background

Genetic association studies have elucidated the link of variants in the interleukin 17 (IL-17) family genes with susceptibility to human diseases, yet have obtained controversial outcomes. Therefore, we sought to update comprehensive synopsis of variants in the IL-17 family genes with susceptibility to human diseases.

Methods

Our study screened the Pubmed and Web of Science to enroll eligible articles and performed a meta-analysis, then graded the cumulative evidence of significant association using Venice criteria and false-positive report probability test, and finally assessed the function of variants with strong evidence.

Results

Seven variants in IL-17 family genes had significant relationships with susceptibility to 18 human diseases identified by meta-analyses. Strong evidence was assigned to 4 variants (IL-17A rs2275913, IL-17A rs8193037, IL-17F rs1889570, IL-17F rs763780) with susceptibility to 6 human diseases (lung and cervical cancer, spondyloarthritis, asthma, multiple sclerosis, rheumatoid arthritis), moderate to 2 variants with risk of 5 diseases, weak to 5 variants with risk of 10 diseases. Bioinformatics analysis suggested that the variants with strong evidence might fall in putative functional regions. Additionally, positive relationships for 5 variants with risk of 4 diseases (based on two datasets) and 14 variants with risk of 21 diseases (based on one dataset) were considered noteworthy.

Conclusions

This study offers updated and comprehensive clues that variants in the IL-17 family genes are significantly linked with susceptibility to cervical, lung cancer, asthma, multiple sclerosis, rheumatoid arthritis and spondyloarthritis, and elucidates the crucial role of the IL-17 regions in the genetic predisposition to cancer or noncancerous diseases.

A potential association between psoriasin to rs4819554 of IL-17RA gene polymorphism in psoriasis Egyptian patients

Interleukin 17 (IL-17) is one of the pro-inflammatory cytokine. Psoriasin is a noticeably over-expressed protein found in the skin lesions of psoriatic patients. Our current study was planned to examine the association of (- 947 A/G) single nucleotide polymorphism (SNP) in IL-17RA promoter region (rs4819554) with psoriasis susceptibility in Egyptian psoriatic patients. Our study included 100 patients and 100, age as well as sex matched, control groups. IL-17RA SNP association was studied using allelic discrimination. RT-qPCR and ELISA were done to assess IL-17 expression. ELISA was performed to assess psoriasin expression. Our study showed a significant association between IL-17 rs4819554 SNP and psoriasis risk, evidenced by higher G allele and AG genotype frequencies in psoriatic patients when compared to controls (allelic: OR 2.283, 95% CI 1.321-3.946, p = 0.003, and genotype: OR 3.026, 95% CI 1.356-6.752, p = 0.007). Additionally, serum psoriasin level was significantly increased when comparing psoriatic patients to controls (p = 0.0003). Moreover, significant increase in IL 17 gene and protein level in AA, AG psoriatic genotypes compared to the corresponding genotypes in normal control (p = 0.0004). IL-17 rs4819554 is significantly associated with psoriasis, and with psoriasin level, in the Egyptian population.

Genetic polymorphisms of IL-17A rs2275913, rs3748067 and IL-17F rs763780 in gastric cancer risk: evidence from 8124 cases and 9873 controls

Interleukin-17 (IL-17) is a critical cytokine involved in inflammation-associated cancers. Single nucleotide polymorphisms (SNPs) might promote carcinogenesis. In this current meta-analysis, we investigated the association of IL-17A and IL-17F gene polymorphisms with gastric cancer (GC) risk. Eligible genetic association studies were retrieved from PubMed, Web of Science and Scopus database sources. Two reviewers independently assessed methodological quality and extracted data from eligible articles. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were calculated. Quantitative data synthesis was conducted using comprehensive meta-analysis v2. Subgroup analysis and heterogeneity analysis were performed. Begg's funnel plot and Egger's regression tests were used to judge publication bias. In silico data analysis was executed to analyze the functional and structural impact of the SNPs. A total of 21 case-control studies for rs2275913 c.-197G > A (7660 patients and 9409 controls), 9 studies for rs3748067 c.*1249C > T (3378 patients and 4120 controls), and 14 studies for rs763780 c.482A > G (4481 patients and 5354 controls) were included. The pooled estimate revealed an association between IL-17A rs2275913 polymorphism and the risk of GC under all genetic models (A vs. G, OR 1.187, 95% CI 1.086-1.297, P < 0.001; GA vs. GG, OR 1.108, 95% CI 1.008-1.218, P = 0.033; AA vs. GG, OR 1.484, 95% CI 1.236-1.781, P < 0.001), while no evidence of association was found with IL-17A rs3748067 or IL-17F rs763780 polymorphisms. Our results showed that IL-17A promoter rs2275913 variant might represent a potential risk factor for gastric cancer susceptibility.

Relationship of IL-17A and IL-17F genetic variations to cervical cancer risk: a meta-analysis

Aim: We performed a meta-analysis to determine a more precise relationship of IL-17A and IL-17F polymorphisms with cervical cancer risk. Materials & methods: PubMed, CNKI and Wan Fang databases were searched for studies on these associations using STATA version 10.0 software. Results: Five studies were included. The AG and AA genotypes and A allele of IL-17A rs2275913 were correlated with an elevated risk of cervical cancer. The TT genotype and T allele of IL-17A rs3748067 and the CC genotype and C allele of IL-17F rs763780 carried a moderate risk of cervical cancer, when compared with the wild-type genotype. Conclusion: IL-17A and IL-17F polymorphisms therefore have the potential to act as predictive biomarkers for cervical cancer risk.

Association of interleukin-17 gene polymorphisms and Helicobacter pylori infection with gastric cancer susceptibility: a cumulative and comprehensive meta-analysis

BACKGROUND

The association between Interleukin-17(IL-17) gene polymorphisms and Helicobacter pylori (H. pylori) infection and gastric cancer susceptibility were inconsistent. We therefore performed a comprehensive meta-analysis about all three genetic polymorphisms of IL-17 to derive a more precise estimation.

METHODS

PubMed, Embase, CNKI and Wanfang databases were researched on the associations between IL-17A rs2275913G>A, rs3748067C>T and IL-17F rs763780 T>C and gastric cancer risk. Odds ratio (OR) with a 95% confidence interval (CI) was applied to assess the relationships. Publication bias, sensitivity and cumulative analysis was conducted to guarantee the strength of meta-analysis.

RESULTS

Overall, eleven related studies involving 4,478 cases and 5,612 controls were collected. Significantly increased risk between IL-17A rs2275913G>A polymorphism and gastric cancer were observed (A vs. G: OR = 1.22, 95% CI = 1.08-1.37, P<0.01, I(2) = 72.3%; AA vs. GG: OR = 1.55, 95% CI = 1.21-1.99, P<0.01, I(2) = 74.3%; GA + AA vs. GG: OR = 1.19, 95% CI = 1.05-1.39, P<0.01, I(2) = 48.2%; AA vs. GG + GA: OR = 1.50, 95% CI = 1.16-1.95, P<0.01, I(2) = 81.2%). For IL-17F rs3748067C>T and rs763780 T>C polymorphisms, only few significantly increased risk could be found in genetic models. Moreover, H. pylori infection also be proved to increase the risk of gastric cancer combined with rs3748067C>T mutation.

CONCLUSIONS

Our meta-analysis suggests that the three IL-17 polymorphisms were associated with a significantly increased risk of gastric cancer, especially in Chinese.

-148 C/T polymorphism of Axin2 contributes to a decreased risk of cancer: evidence from a meta-analysis

Several studies have reported an association between -148 C/T polymorphism of Axis inhibition protein 2 (Axin2) and cancer risk; however, the results are inconsistent. In this study, a meta-analysis was performed to assess the association between -148 C/T polymorphism of Axin2 and susceptibility to cancer. Published case-control and cohort-based studies from PubMed, Embase, Wanfang, and CNKI were retrieved, and data were manually extracted. The odds ratios (ORs) and 95% confidence intervals (CIs) of the included studies were pooled. Begg's and Egger's tests were used to evaluate publication bias. Cumulative and recursive cumulative meta-analyses (CMA) were performed as evidence accumulated to investigate the trends and stability of the effect size. Nine articles with 1,664 cases and 1,796 controls were included. The pooled effect size showed an association between -148 C/T polymorphism and the risk of cancer (dominant model, OR: 0.72, 95% CI: 0.63-0.83; allele model, OR: 0.81, 95% CI: 0.73-0.90). CMA showed an association trend, and the recursive CMA indicated that more evidence is needed to make conclusions about significance. In a subgroup analysis, a significant association between -148 C/T polymorphism and low cancer susceptibility was detected for lung cancer (dominant model, 0.69, 95% CI: 0.56-0.85; recessive model, OR: 0.75, 95% CI: 0.56-0.99; allele model, 0.76, 95% CI: 0.66-0.86). The -148 C/T polymorphism was also associated with low cancer susceptibility among Asians (dominant model, OR: 0.68, 95% CI: 0.57-0.81; recessive model, OR: 0.75, 95% CI: 0.56-0.99; allele model, OR: 0.76, 95% CI: 0.66-0.86). The Axin2 -148 C/T polymorphism was found to be significantly associated with a decreased risk of cancer, particularly lung cancer, in Asians and population-based controls. Thus, Axin2 should be considered as a potential therapeutic target for preventing tumor growth.