Interleukin-17 gene polymorphisms are associated with bladder cancer in a Chinese Han population

Variable roles of interleukin-17F in different cancers

BACKGROUND

Interleukin (IL)-17 family is a group of six cytokines that plays a central role in inflammatory processes and participates in cancer progression. Interleukin-17A has been shown to have mainly a protumorigenic role, but the other members of the IL-17 family, including IL-17F, have received less attention.

METHODS

We applied systematic review guidelines to study the role of IL-17F, protein and mRNA expression, polymorphisms, and functions, in cancer. We carried out a systematic search in PubMed, Ovid Medline, Scopus, and Cochrane libraries, yielding 79 articles that met the inclusion criteria.

RESULTS

The findings indicated that IL-17F has both anti- and protumorigenic roles, which depend on cancer type and the molecular form and location of IL-17F. As an example, the presence of IL-17F protein in tumor tissue and patient serum has a protective role in oral and pancreatic cancers, whereas it is protumorigenic in prostate and bladder cancers. These effects are proposed to be based on multiple mechanisms, such as inhibition of angiogenesis, vasculogenic mimicry and cancer cell proliferation, migration and invasion, and aggravating the inflammatory process. No solid evidence emerged for the correlation between IL-17F polymorphisms and cancer incidence or patients' prognosis.

CONCLUSION

IL-17F is a multifaceted cytokine. There is a clear demand for more well-designed studies of IL-17F to elucidate its molecular mechanisms in different types of cancer. The studies presented in this article examined a variety of different designs, study populations and primary/secondary outcomes, which unfortunately reduces the value of direct interstudy comparisons.

Polymorphisms in IL-17A Gene and Susceptibility of Colorectal Cancer in Bangladeshi Population: A Case-Control Analysis

OBJECTIVE

Interleukin-17A (IL-17A) genetic polymorphisms are associated with multiple cancer types, including colorectal cancer (CRC). However, no previous study was performed in the Bangladeshi population to evaluate the association. Our study aimed to find the association between two IL-17A variants (rs10484879 C/A and rs3748067 G/A) and susceptibility of CRC.

METHODS AND MATERIALS

This retrospective case-control study comprised 292 CRC patients and 288 age, sex, and BMI matched healthy volunteers. Genotyping of both variants was done by the tetra-primer ARMS-PCR method, and the results were analyzed by the SPSS software package (version-25.0).

RESULTS

Logistic regression analysis indicated that in case of IL-17A rs10484879 polymorphism, AC and AA genotype carriers showed 2.44- and 3.27-times significantly increased risk for CRC development (OR = 2.44, P = .0008 and OR = 3.27, P = .0133, individually). A significant association was also observed for AC + AA genotype (OR = 2.58, P = .0001). Again, over-dominant and allelic model revealed statistically significant link to CRC risk (OR = 2.13, P = .0035 and OR = 2.22, P = .001). For rs3748067 polymorphism, AG and AA genotype carriers showed 2.30- and 2.45-times enhanced risk for CRC (OR = 2.30, P = .005 and OR = 2.45, P = .031). A statistically significant association was also observed for AG + AA genotype (OR = 2.35, P = .001), over-dominant model (OR = 2.05, P = .014), and allelic model (OR = 2.11, P = .0004).

CONCLUSION

This study highlights that IL-17A rs10484879 and rs3748067 polymorphisms may be associated with CRC development. However, further functional research with larger samples may reveal more statistically significant outcomes.

Associations of IL-17A -197G/A and IL-17F 7488T/C polymorphisms with cancer risk in asians: An updated meta-analysis from 43 studies

OBJECTIVE

Numerous epidemiological studies have been published to elucidate the potential associations of IL-17A -197G/A (rs2275913) and IL-17F 7488T/C (rs763780) with cancer risk in Asians. Nevertheless, the results from different studies remain controversial. To identify the roles of the two polymorphisms in cancer risk, we performed this current meta-analysis.

METHODS

The available literature was derived from five databases, covering relevant articles updated through February 17, 2021. Five different analysis models with corresponding odds ratios (ORs) and 95% confidence intervals (CIs) were applied to appraise the gene-disease correlation.

RESULTS

In total, 43 case-control studies with 31,237 subjects were enrolled. Overall analyses indicated that there was significantly increased cancer risk led by IL-17A -197G/A under the five analysis models. A similar tendency was also identified in the subgroup analysis of cancer type, especially for gastric cancer, cervical cancer, colorectal cancer, and oral carcinoma. As for IL-17F 7488T/C, we revealed that patients who carried this variant had a higher cancer risk in the recessive model among the overall analyses, as well as subgroup analyses of cervical cancer or oral carcinoma.

CONCLUSIONS

In summary, our work confirmed that IL-17A -197G/A acted as a risk factor for diverse cancer types and that IL-17F 7488T/C might be involved in cervical cancer and oral carcinoma.

Polymorphisms at the IL17A and IL17RA genes are associated with prognosis of papillary thyroid carcinoma

BACKGROUND

Interleukin (IL)-17A has a dual role in tumor immunity, promotes anti-tumor responses and facilitates angiogenesis by interacting with IL-17 receptor A (IL-17RA). Although IL-17A has been associated with the pathogenesis of papillary thyroid carcinoma (PTC), the nucleotide variability at the IL17A and IL17RA genes is still poorly characterized.

AIM

To assess the contribution of the IL17A (-197 G >A, rs2275913) and IL17RA (-947 A >G, rs4819554) single nucleotide polymorphisms (SNP) on the development and progression of PTC and on IL-17 plasma levels.

METHODS

We studied 188 PTC patients and 170 healthy controls. SNPs were identified using PCR-amplified DNA and restriction fragment length polymorphism (RFLP) techniques. Plasma levels of IL-17A was evaluated in 83 PTC patients using ELISA. Statistical analyses were performed to evaluate the associations between SNPs and clinicohistopathological features of PTC and IL-17A levels.

RESULTS

No significant difference was observed regarding the allele and genotype distributions of both SNPs between PTC patients and controls. The IL17A GA was associated with poor biochemical and structural incomplete response to therapy, whereas no influence over the IL-17A expression was observed. The IL17RA AG was significantly associated with small-sized tumors, initial tumor stage at diagnosis and better response to therapy.

CONCLUSIONS

The IL17A SNP may predict an aggressive manifestation of PTC, whereas the IL17RA SNP was associated with a more favorable clinical outcome.

The Interplay between Oxidative Stress, Inflammation and Angiogenesis in Bladder Cancer Development

In 2018, 550,000 people were diagnosed with bladder cancer (BC), of which nearly 200,000 people died. Moreover, men are 4 times more likely than women to be diagnosed with BC. The risk factors include exposure to environmental and occupational chemicals, especially tobacco smoke, benzidine and genetic factors. Despite numerous studies, the molecular basis of BC development remains unclear. A growing body of evidence suggests that inflammation, oxidant-antioxidant imbalance and angiogenesis disorders may play a significant role in the development and progression of bladder cancer. The patients with bladder cancer were characterised by an increased level of reactive oxygen species (ROS), the products of lipid peroxidation, proinflammatory cytokines and proangiogenic factors as compared to controls. Furthermore, it was shown that polymorphisms localised in genes associated with these pathways may modulate the risk of BC. Interestingly, ROS overproduction may induce the production of proinflammatory cytokines, which finally activated angiogenesis. Moreover, the available literature shows that both inflammation and oxidative stress may lead to activation of angiogenesis and tumour progression in BC patients.

Screening and identification of hub genes in bladder cancer by bioinformatics analysis and KIF11 is a potential prognostic biomarker

Bladder cancer (BC) is the ninth most common lethal malignancy worldwide. Great efforts have been devoted to clarify the pathogenesis of BC, but the underlying molecular mechanisms remain unclear. To screen for the genes associated with the progression and carcinogenesis of BC, three datasets were obtained from the Gene Expression Omnibus. A total of 37 tumor and 16 non-cancerous samples were analyzed to identify differentially expressed genes (DEGs). Subsequently, 141 genes were identified, including 55 upregulated and 86 downregulated genes. The protein-protein interaction network was established using the Search Tool for Retrieval of Interacting Genes database. Hub gene identification and module analysis were performed using Cytoscape software. Hierarchical clustering of hub genes was conducted using the University of California, Santa Cruz Cancer Genomics Browser. Among the hub genes, kinesin family member 11 (KIF11) was identified as one of the most significant prognostic biomarkers among all the candidates. The Kaplan Meier Plotter database was used for survival analysis of KIF11. The expression profile of KIF11 was analyzed using the ONCOMINE database. The expression levels of KIF11 in BC samples and bladder cells were measured using reverse transcription-quantitative pCR, immunohistochemistry and western blotting. In summary, KIF11 was significantly upregulated in BC and might act as a potential prognostic biomarker. The present identification of DEGs and hub genes in BC may provide novel insight for investigating the molecular mechanisms of BC.

Polymorphisms of genes encoding cytokines predict the risk of high-grade bladder cancer and outcomes of BCG immunotherapy

Introduction

The present study investigated the association of cytokines genes polymorphisms (IL-2, IL-8 and IL-18) and polymorphisms in genes encoding molecules related to the differentiation of Th17 subpopulation (IL-17 and IL-23R) with the risk of bladder cancer (BC) and response to BCG immunotherapy.

Material and methods

Altogether, 175 BC patients treated with BCG due to high-grade non-muscle invasive tumors and 207 healthy individuals were genotyped for the following polymorphisms: IL-17A-197G>A (rs2275913); IL-17F+7488T>C (rs763780); IL-23Rc.309C>A (rs10889677);IL-23Rc.1142G>A (rs11209026); IL-2-330T>G (rs2069762), IL-8-251A>T (rs4073), and IL-18-137G>C (rs187238) using the TaqMan SNP genotyping assays.

Results

The IL-23Rc.-309C>A[A] allele was associated with the risk of BC (OR: 1.42, p = 0.03). Moreover, heterozygocities for IL-17A-197G>A[GA] and IL-18-137G>C[GC] increased the risk of BC, as compared to both homozygotes (OR: 1.67, p = 0.01 and OR: 1.84, p = 0.008, respectively). The IL-18-137G>C[GC] heterozygous patients had the highest risk of tumor recurrence and progression, and the worst recurrence-free and progression-free survival. Homozygous IL-17A-197G>A[GG] patients presented the best recurrence-free survival, while IL-17A-197G>A[AA] patients had 1.8-fold higher risk of recurrence.

Conclusions

The present study highlighted the importance of IL-17, IL-18, and IL-23R gene polymorphisms for BC susceptibility and BCG immunotherapy outcomes. It may help to identify appropriate candidates for early radical treatment.

Systematic Review: Genetic Associations for Prognostic Factors of Urinary Bladder Cancer

INTRODUCTION

Many germline associations have been reported for urinary bladder cancer (UBC) outcomes and prognostic characteristics. It is unclear whether there are overlapping genetic patterns for various prognostic endpoints. We aimed to review contemporary literature on genetic associations with UBC prognostic outcomes and to identify potential overlap in reported genes.

METHODS

EMBASE, MEDLINE, and PubMed databases were queried for relevant articles in English language without date restrictions. The initial search identified 1346 articles. After exclusions, 112 studies have been summarized. Cumulatively, 316 single-nucleotide polymorphisms (SNPs) were reported across prognostic outcomes (recurrence, progression, death) and characteristics (tumor stage, grade, size, age, risk group). There were considerable differences between studied outcomes in the context of genetic associations. The most commonly reported SNPs were located in OGG1, TP53, and MDM2. For outcomes with the highest number of reported associations (ie, recurrence and death), functional enrichment annotation yields different terms, potentially indicating separate biological mechanisms.

CONCLUSIONS

Our study suggests that all UBC prognostic outcomes may have different biological origins with limited overlap. Further validation of these observations is essential to target a phenotype that could best predict patient outcome and advance current management practices.

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.

Inflammatory cytokines in bladder cancer

The presence of inflammatory cells and their products in the tumor microenvironment plays a crucial role in the pathogenesis of a tumor. Releasing the cytokines from a host in response to infection and inflammation can inhibit tumor growth and progression. However, tumor cells can also respond to the host cytokines with increasing the growth/invasion/metastasis. Bladder cancer (BC) is one of the most common cancers in the world. The microenvironment of a bladder tumor has been indicated to be rich in growth factors/inflammatory cytokines that can induce the tumor growth/progression and also suppress the immune system. On the contrary, modulate of the cancer progression has been shown following upregulation of the cytokines-related pathways that suggested the cytokines as potential therapeutic targets. In this study, we provide a summary of cytokines that are involved in BC formation/regression with both inflammatory and anti-inflammatory properties. A more accurate understanding of tumor microenvironment creates favorable conditions for cytokines targeting to treat BC.

Association of interleukin-17A polymorphisms with the risk of colorectal cancer: A case-control study

BACKGROUND

Interleukin (IL)-17A is proinflammatory cytokine produced by Th17 cells, which play key, but sometimes inconsistent role in autoimmunity and cancer. Polymorphic variants in IL-17A gene were differentially associated with susceptibility to cancer, including colorectal cancer (CRC).

AIM

We investigated the association between six IL-17A gene variants (rs3819024, rs2275913, rs3819025, rs10484879, rs7747909, and rs3748067) with CRC susceptibility in Tunisians.

SUBJECTS AND METHODS

Retrospective case-control study. Study subjects comprised 293 patients with CRC, and 268 age-, gender-, and BMI-matched healthy controls. IL-17A genotyping was done by real-time PCR, with defined clusters.

RESULTS

Of the seven tested IL-17A tag-SNPs, minor allele frequency (MAF) of rs10484879 was significantly higher in CRC patients than control subjects. Heterozygous rs10484879 [OR (95% CI) = 2.63 (1.64-4.21)] was associated with higher risk, while carriage of heterozygous rs3748067 genotype was associated with reduced risk of CRC [OR (95% CI) = 0.56 (0.37-0.84)], respectively. Carriage of rs10484879 minor allele correlated with positive family history of CRC and other cancers (P = 0.002), CRC staging (P = 0.044), CRC treatment (P = 0.038), and with chemo body reaction (P = 0.001). Of the 7 IL-17A variants, 4 were in linkage disequilibrium, hence allowing for construction of 4-locus haplotypes. Varied linkage disequilibrium (LD) was noted between the even tested IL-17A variants, and further analysis was limited to only 4-locus (rs3819024-rs2275913- rs10484879-rs7747909). Haploview analysis identified the 4-locus IL-17A haplotypes AGTG (P < 0.011), and GATG (P = 0.036) to be positively associated with CRC, after controlling key covariates.

CONCLUSION

IL-17A rs10484879 SNP, and IL-17A haplotypes AGGTG and GAGTG constitute independent factors of CRC susceptibility. We propose that IL-17A may be a target for future CRC immunotherapy.

Polymorphisms in the IL-17 Gene (rs2275913 and rs763780) Are Associated with Hepatitis B Virus Infection in the Han Chinese Population

AIM

Interleukin-17 (IL-17) can accelerate the release of many pro-inflammatory cytokines. The purpose of our study was to investigate the potential association between polymorphisms in the IL-17 gene and susceptibility to hepatitis B virus (HBV) infection in the Han Chinese population.

METHODS

We recruited 596 HBV-infected patients and 612 ethnically matched controls, who were then genotyped for the IL-17A and IL-17F polymorphisms, rs2275913 and rs763780, respectively, by using TaqMan probe-based real-time polymerase chain reaction. The frequencies of the alleles and genotypes in patients and controls were compared by the χ² test.

RESULTS

Statistically significant differences in genotypic and allelic frequencies were revealed at both polymorphic sites between HBV-positive patients and controls (rs2275913: genotype χ² = 37.74, p < 0.001 and allele χ² = 22.17, p < 0.001, odds ratio [OR] = 0.654, 95% confidence interval [CI] = 0.548-0.781. rs763780: genotype χ² = 19.80, p < 0.001 and allele χ² = 18.78, p < 0.001, OR = 0.507, 95% CI = 0.371-0.692).

CONCLUSIONS

These results indicate that the IL-17A rs2275913 and IL-17F rs763780 polymorphisms are associated with HBV infection in the Han Chinese population. We conclude that possession of the GG genotype and the G allele at rs2275913, and the TT genotype and the T allele at rs763780 might increase the risk of HBV infection. Larger-scale, multiracial studies are necessary to evaluate the role of IL-17 polymorphisms in relation to an enhanced risk of HBV infection.

IL17RA gene variants and anti-TNF response among psoriasis patients

Polymorphisms at genes encoding proteins involved in the pathogenesis of psoriasis (Psor) or in the mechanism of action of biological drugs could influence the treatment response. Because the interleukin (IL)-17 family has a central role in the pathogenesis of Psor, we hypothesized that IL17RA variants could influence the response to anti-TNF drugs among Psor patients. To address this issue we performed a cross-sectional study of Psor patients who received the biological treatments for the first time, with a follow-up of at least 6 months. All of the patients were Caucasian, older than 18 years old, with chronic plaque Psor, and had completed at least 24 weeks of anti-TNF therapy (adalimumab, etanercept or infliximab). The treatment response to anti-TNF agents was evaluated according to the achievement of PASI50 and PASI75 at weeks 12 and 24. Those who achieved PASI75 at week 24 were considered good responders. All patients were genotyped for the selected single-nucleotide polymorphisms (SNPs) at IL17RA gene. A total of 238 patients were included (57% male, mean age 46 years). One hundred and five patients received adalimumab, 91 patients etanercept and 42 infliximab. The rs4819554 promoter SNP allele A was significantly more common among responders at weeks 12 (P=0.01) and 24 (P=0.04). We found a higher frequency of AA versus AG+GG among responders, but the difference was only significant at week 12 (P=0.03, odd ratio=1.86, 95% confidence of interval=1.05-3.27). Thus, in the study population, the SNP rs4819554 in the promoter region of IL17RA significantly influences the response to anti-TNF drugs at week 12.

Common variants in IL-17A/IL-17RA axis contribute to predisposition to and progression of congestive heart failure

Heart failure is characterized by immune activation leading to production and release of proinflammatory cytokines. Interleukin 17A (IL-17A) is a proinflammatory cytokine and multiple lines of evidence from animal and human studies suggest crucial roles of IL-17A in heart failure. Therefore, we investigated whether common polymorphisms of genes IL17A and IL17RA (coding interleukin 17 receptor A) contribute to genetic predisposition to heart failure and adverse clinical outcomes associated with it.A total of 1713 adult patients with congestive heart failure and 1713 age- and sex-matched controls were genotyped for promoter single nucleotide polymorphisms (SNPs), rs2275913 and rs8193037 in IL17A and rs4819554 in IL17RA, to assess the relationship between individual SNPs and the risk of congestive heart failure. Results showed that rs8193037 in IL17A was associated with the risk of congestive heart failure (odds ratio [OR] = 0.76; 95% confidence interval [CI] 0.63-0.90, adjusted P = 0.002) after adjustment for multiple cardiovascular risk factors including age, sex, smoking status, diabetes, hypertension, and dyslipidemia. This association was evident in both ischemic and nonischemic heart failure (P = 0.005 and P = 0.05, respectively). Furthermore, prospective follow-up of 12.7 months for the occurrence of adverse clinical outcomes showed that rs4819554 in IL17RA was significantly associated with cardiovascular mortality (hazard ratio [HR] = 1.28; 95% CI = 1.02-1.59, adjusted P = 0.03) after adjustments for multiple cardiovascular risk factors and New York Heart Association functional class.This study demonstrated associations of rs8193037 in the promoter of IL17A with the risk of congestive heart failure, and of rs4819554 in the promoter of IL17RA with the risk of cardiovascular mortality in patients with congestive heart failure. These data lend further support to the notion that immune activation and genetic polymorphisms contribute to heart failure pathogenesis and progression.

Association of IL-17A and IL-17F gene polymorphisms with chronic hepatitis B and hepatitis B virus-related liver cirrhosis in a Chinese population: A case-control study

BACKGROUND

Interleukin (IL)-17 has been shown to play an important role in tissue inflammation and in the pathogenesis of immune-related liver damage. Genetic variations in IL-17 gene may be associated with the development of hepatitis B virus (HBV) infection. However, literature is scanty regarding their association.

METHODS

We conducted a case-control study including 433 subjects (171 healthy controls, 130 patients with chronic hepatitis B [CHB]; and 132 patients with HBV-related liver cirrhosis [HBV-LC] to assess the association between IL-17A rs4711998, IL-17A rs2275913 and IL-17F rs763780 polymorphisms and risk of CHB and HBV-LC. Genotypes were determined by polymerase chain reaction-restriction fragment length polymorphism and DNA sequencing.

RESULTS

Our results revealed a statistically significant association between IL-17A rs4711998 G allele and increased risk of HBV-LC risk (OR=1.541, 95% CI 1.057-2.246, P=0.025). Subjects carrying the IL-17A rs4711998 AG genotype were 1.75 times more likely to develop HBV-LC (OR=1.757, 95% CI 1.096-2.817, P=0.026). Stratification analysis indicated that IL-17A rs4711998 G allele and AG genotype enhanced the risk of HBV-LC development among men and older age (≥50years) subject groups. In addition, we found that GCT haplotype also might be a risk factor for HBV-LC (OR=2.448, 95% CI 1.137-5.271, P=0.019). Furthermore, no significant association between IL-17A rs2275913 and IL-17F rs763780 polymorphisms and CHB, HBV-LC risk was observed (P>0.05).

CONCLUSION

Our data provide the first evidence that the IL-17A rs4711998 genetic variant may contribute to HBV-LC susceptibility in a Chinese population.

Role of IL-17A rs2275913 and IL-17F rs763780 polymorphisms in risk of cancer development: an updated meta-analysis

Single nucleotide polymorphisms (SNPs) in the interleukin-17 (IL-17) gene have been shown to be correlated with susceptibility to cancer. However, various studies report different results of this association. The aim of the present work was to clarify the effects of IL-17A G197A (rs2275913) and IL-17F T7488C (rs763780) polymorphisms on cancer risk. We performed systematic searches of the PubMed and CNKI databases to obtain relevant publications. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to evaluate the association of rs2275913 and rs763780 polymorphisms with cancer risk. Data were extracted from the selected studies, and statistical analysis was conducted using the STATA software. Our results indicated that rs2275913 and rs763780 polymorphisms significantly increase cancer risk, especially in gastric cancers. Subgroup analysis suggested the existence of a significant correlation between rs763780 polymorphism and cancer susceptibility in Caucasian populations. This updated meta-analysis confirms that rs2275913 and rs763780 polymorphisms are highly associated with increased risk for multiple forms of cancer.

Association Between IL-17A +197 G/A Polymorphism and Cancer Risk: A Meta-analysis

AIMS

The association between interleukin-17 (IL-17) gene polymorphism and cancer is controversial. Thus, we performed a meta-analysis to evaluate the correlation between this gene variant and cancer risk.

MATERIALS AND METHODS

We retrieved the available data from EMBASE and PUBMED through June, 2015, and evaluated the effect of the rs2273913 polymorphism in different ethnicities and cancer types. A meta-analysis was performed after data sorting.

RESULTS

Significant associations were confirmed among Asians by the allelic model (T allele vs. G allele, 95% confidence interval [95% CI] 1.304-2.120), homozygote comparison (AA vs. GG, 95% CI 1.073-1.615), and the recessive model (AA vs. AG/GG, 95% CI 1.128-1.778). We also demonstrated that rs2273913 confers a high risk of nongastrointestinal cancer based on the allelic model (T allele vs. G allele, 95% CI 2.288-3.442), homozygote comparison (AA vs. GG, 95% CI 1.312-1.925), and recessive model (AA vs. AG/GG, 95% CI 1.259-1.689).

CONCLUSIONS

Our present study indicates that the IL-17A +197 G/A/T polymorphism (rs2275913) is associated with the risk of cancer in Asian populations and nongastrointestinal cancers. Hence, rs2275913 might be useful as a diagnostic biomarker of cancer in these populations.

The IL-17A G-197A and IL-17F 7488T/C polymorphisms are associated with increased risk of cancer in Asians: a meta-analysis

Background

Interleukin-17 (IL-17) is a family of emerged pro-inflammatory cytokines. The IL-17A and IL-17F are two important members of IL-17 family. Previous studies have shown that the functional IL-17A G-197A and IL-17F 7488T/C polymorphisms may contribute to susceptibility to cancer but the results were inconclusive. This meta-analysis was performed to determine the exact association between IL-17 polymorphisms and cancer risk.

Methods

Online databases were searched to identify eligible case–control studies. Pooled odds ratios (ORs) and confidence intervals (CIs) were calculated by fixed-effect models or random-effect models. Publication bias was detected by Egger’s test and Begg’s test.

Results

Nine eligible case–control studies of IL-17A G-197A and seven studies of IL-17F 7488T/C, including 3,181 cases and 4,005 controls, were identified. Pooled analysis suggested the variant IL-17A-197A allele was associated with increased risk cancer (GA/AA vs GG, OR =1.27, 95% CI: 1.15, 1.41, P_{heterogeneity} =0.374; and A vs G, OR =1.30, 95% CI: 1.17, 1.45, P_{heterogeneity} =0.021). For IL-17F 7488T/C, the homozygote 7488CC genotype significantly increased risk of cancer (CC vs TC/TT, OR =1.36, 95% CI: 0.97, 1.91, P_{heterogeneity} =0.875; and CC vs TT, OR =1.39, 95% CI: 1.03, 1.88, P_{heterogeneity} =0.979), especially for gastric cancer.

Conclusion

The variant IL-17A-197A allele and IL-17F 7488CC genotype were associated with increased risk of cancer, especially for gastric cancer.

Association between the interleukin-17A -197G>A (rs2275913) polymorphism and risk of digestive cancer

Interleukin-17A (IL-17A) is a multifunctional cytokine which plays a crucial role in the initiation and progression of cancer. To date, several studies have investigated associations between IL-17A -197G>A (rs2275913) polymorphism and digestive cancer risk, but the results remain conflicting. We here aimed to confirm the role of this single nucleotide polymorphism (SNP) in susceptibility to digestive cancer through a systemic review and meta-analysis. Ten eligible case-control studies were identified by searching electronic databases, involving 3,087 cases and 3,815 controls. Odds ratios (ORs) and corresponding 95% confidence intervals (CIs) were used to estimate the strength of the association. The results of overall analyses indicated that the variant A allele was associated with an increased risk of digestive cancer (AA vs GG: OR=1.51, 95%CI=1.18-1.93; AA vs GG+GA: OR=1.45, 95%CI=1.12-1.87; A vs G: OR=1.21, 95%CI=1.05-1.39). In subgroup analysis stratified by specific cancer type, elevated risk among studies of gastric cancer was found (AA vs GG: OR=1.68, 95%CI=1.24-2.28; AA vs GG+GA: OR=1.62, 95%CI=1.16-2.26; A vs G: OR=1.23, 95%CI=1.04-1.46). According to ethnicity, there was evidence in the Asian populations for an association between this polymorphism and cancer risk (GA vs GG: OR=1.19, 95%CI=1.05-1.36; AA vs GG: OR=1.56, 95%CI=1.15-2.12; AA+GA vs GG: OR=1.28, 95%CI=1.13- 1.44; AA vs GG+GA: OR=1.42, 95%CI=1.01-2.00; A vs G: OR=1.24, 95%CI=1.08-1.44), while in the Caucasian populations an association was found in the recessive model (AA vs GG+GA: OR=1.62, 95%CI=1.17-2.24). In conclusion, the results of this meta-analysis suggest that the IL-17A -197G>A polymorphism contributes to an increased risk of human digestive cancer, both in the Asian and Caucasian populations and especially for gastric cancer.

Meta analysis of association of the IL-17F rs763780T>C gene polymorphism with cancer risk

PURPOSE

To investigate the association of IL-17F rs763780T>C with cancer risk.

MATERIALS AND METHODS

We searched the Cochrane Central Library, PubMed, MEDLINE, EMBASE, CNKI (China National Knowledge Infrastructure) and WangFang databases until May 2014 for a meta-analysis conducted using RevMan 5.2 software.

RESULTS

A total of ten papers were included into this meta analysis, involving 3, 336 cases and 4, 217 healthy people. There were no significant differences on association of IL-17F rs763780T>C polymorphism with cancer risk except in the CC vs TT genetic model. Although the the risk in the gastric cancer group is higher than that in control group, there were no significant differences on the association of IL-17F rs763780T>C polymorphism with other cancers.

CONCLUSIONS

Our meta analysis reveal the IL-17A rs763780T>C gene polymorphism is involved in risk of gastric cancer but not other tumor types.

Involvement of IL17A, IL17F and IL23R Polymorphisms in Colorectal Cancer Therapy

IL23/IL17 pathway plays an important role in the development of inflammatory bowel diseases (IBD). In general, the genes encoding the cytokines are genetically polymorphic and polymorphisms in genes IL23R and IL17 have been proved to be associated with its susceptibility to inflammatory diseases as well as cancer including colorectal cancer. Moreover, it has been shown that these interleukins are involved in anti-tumor or pro-tumor effects of various cancers. Previously, we showed that there is a significant association between IL17A, IL17F and IL23R polymorphisms as well as the occurrence of colorectal cancer and the clinical features of the disease. The purpose of the present work is to investigate an association between IL17A, IL17F and IL23R polymorphisms in 102 Tunisian patients with colorectal cancer treatment. The association was analyzed by statistical tools. We found that patients with mutated genotypes of IL17A G197A SNP could be a risk factor for the inefficiency of chemotherapy and radiotherapy. Unlike IL17F variant, patients with wild type genotypes require surgery and adjuvant chemotherapy. On the one hand, we found no evidence that supports a significant association between IL23R polymorphism and the combined genotypes of these three genes and the colorectal cancer treatment. On the other hand, we showed that there is an important interaction between IL17A/IL17F polymorphisms and the stage of the disease as well as its treatment. Finally, patients with IL17F wild type genotype highlighted that there is a valid longer OS without all treatments and with radiotherapy and a neoadjuvant chemotherapy. In contrast, we observed that there are no relationships between IL17A, IL23R and the survival of these patients neither with nor without the treatment. Our results suggest that polymorphisms in IL17A and IL17F genes may be a predictive source of colorectal cancer therapy type. Therefore, IL17F may serve as an independent prognostic factor for overall survival in patients with colorectal cancer.

The immune microenvironment of the colorectal tumor: Involvement of immunity genes and microRNAs belonging to the TH17 pathway

Colorectal cancer is a complex and multifactorial disease. Various factors such as genetic, immunological, epigenetic and environmental constitute minor risk factors with their additive effects contributing to the advent of colorectal cancer. In order to evaluate the role of innate and adaptive immunity in the susceptibility, the presentation and the development of colorectal cancer, we considered an immunogenetic approach on polymorphisms in the TLR4 gene and NOD2/CARD15 gene (receptors of innate immunity) as well as in cytokine genes of the TH17 pathway IL17A, IL17F and cytokine receptor IL23R. Then, we evaluated the expression of microRNAs regulated by TLR4 and NOD2/CARD15 or targeting TLR4, IL17 and proinflammatory cytokines (IL-6, TNF) induced by IL17. Through a case-control study, we showed that the polymorphism of IL17A is associated with its susceptibility to colorectal cancer. Considering the tumor location, we found that the mutated alleles of IL17A, IL17F and IL23R are rather associated with colon cancer and not with rectum cancer. This result confirms that the colon and rectum are two different physiological entities. This study shows that TLR4, IL17A/F and IL23R polymorphisms are involved in the presentation of the disease with regard to tumor architecture, histology, and differentiation, advanced stage of the disease and lymph node and metastasis. Overall, these polymorphisms are associated with a poor prognosis of the disease. Furthermore, in order to evaluate the involvement of epigenetic mechanisms in the occurrence of colorectal cancer, we aimed at analyzing the tumor compared to a normal adjacent tissue and the expression of miRNAs (miR21, miR146a, miR135a, miR147b and miR155) that regulate immunity genes especially the cytokines of the TH17 pathway. This research has shown that microRNAs 21, 135a and 146a are associated with colorectal cancer. Indeed, these three miRs are overexpressed in cancer tissue compared to healthy tissue. These results clearly confirm the involvement of epigenetics in colorectal cancer. In other words, this study reveals the importance of immunity and specifically the TH17 pathway in the development and presentation of colorectal cancer. These results suggest that TLR4, IL17A, IL17F and IL23R polymorphisms as well as the expression of microRNAs that regulate inflammation and the TH17 pathway are associated with the evolution and progression of the colorectal tumor that could be considered as biomarkers in colorectal cancer.

Interleukin-17A and interleukin-17F gene polymorphisms and hepatitis B virus-related hepatocellular carcinoma risk in a Chinese population

Interleukin (IL)-17A and IL-17F are inflammatory cytokines, which play a critical function in inflammation. Genetic variations in the IL-17A and IL-17F genes may be associated with a risk of hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC), which is a typical inflammation-related cancer. However, their relationship with HBV-related HCC has not been thoroughly investigated. We conducted a case-control study including 155 patients with HBV-related HCC and 171 healthy controls to assess the association between IL-17A rs4711998, IL-17A rs2275913, and IL-17F rs763780 polymorphisms and risk of HCC. Genotypes were determined by polymerase chain reaction-restriction fragment length polymorphism and DNA sequencing. There were no significant differences in the genotype and allele frequencies of IL-17A rs4711998, IL-17A rs2275913, and IL-17F rs763780 polymorphisms between the HBV-related HCC patients and healthy controls. However, our results revealed a statistically significant association between the ACA haplotype and increased HCC risk [odds ratio (OR) 1.820, 95 % confidence interval (CI) 1.181-2.624, P = 0.013]. In contrast, the GCG haplotype was associated with a significantly decreased risk of HBV-related HCC (OR 0.454, 95 % CI 0.112-0.898, P = 0.035). Our results suggest that IL-17A rs4711998, IL-17A rs2275913, and IL-17F rs763780 polymorphisms do not contribute to HBV-related HCC susceptibility independently. However, the ACA and GCG haplotypes in the IL-17 gene might be a risk factor and a protective marker, respectively, for HBV-related HCC in a Chinese population.

Interleukin-17 gene polymorphisms contribute to cancer risk

Epidemiological studies have suggested that interleukin-17 (IL-17) polymorphisms are associated with cancer risk. However, the results of these studies are inconsistent. Therefore, we performed a meta-analysis to obtain a precise conclusion. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the association of the IL-17A rs2275913G>A and IL-17F rs763780T>C polymorphisms with cancer risk. Publication bias and sensitivity analyses were performed to ensure the statistical power. Overall, 10 relevant case-control studies involving 4,516 cases and 5,645 controls were included. The pooled ORs with 95% CIs indicated that the IL-17A rs2275913G>A polymorphism was significantly associated with increased cancer risk (for A versus G: OR = 1.28, 95% CI: 1.16–1.41, P < 0.001, I² = 61.1%; for GA versus GG: OR = 1.12, 95% CI: 1.02–1.23, P = 0.015, I² = 27.8%; for AA versus GG: OR = 1.71, 95% CI: 1.38–2.41, P < 0.001, I² = 69.6%; for GA + AA versus GG: OR = 1.23, 95% CI: 1.13–1.34, P < 0.001, I² = 6.4%; for AA versus GG + GA: OR = 1.62, 95% CI: 1.27–2.07, P < 0.001, I² = 81.4%). Succeeding analysis of HWE and stratified analysis of gastric cancer and the Asian (and Chinese) population revealed similar results. The IL-17F rs763780T>C polymorphism was also significantly associated with gastric cancer development. Overall, the present meta-analysis suggests that IL-17 polymorphisms increase the risk of developing cancer, particularly gastric cancer, in the Asian (and Chinese) population.

IL-17A G197A and C1249T polymorphisms in gastric carcinogenesis

Interleukin 17A (IL-17A) is a critical cytokine involved in inflammatory diseases and inflammation-associated cancers. Increasing case-control studies have implicated crucial roles of IL-17A single nucleotide polymorphisms (G197A and C1249T) in gastric carcinogenesis, but providing inconclusive findings. The present study is aimed to estimate the association of IL-17A G197A and C1249T polymorphisms with gastric cancer risk by pooling all available publications. A comprehensive literature search in PubMed, Embase, Web of Science, China National Knowledge Infrastructure (CNKI), and Wanfang databases was performed for eligible publications from their inception up to May 5, 2014. The pooled odds ratios (ORs) with corresponding 95 % confidence intervals (CIs) were calculated to estimate the effect of IL-17A polymorphisms on gastric carcinogenesis. Stratified analysis by ethnicity, Helicobacter pylori (H. pylori) infection, and smoking status were also conducted. All analyses were performed by using the Stata 12.0 software. There were five case-control studies with 2,774 cases and 3,162 controls and two case-control studies with 620 cases and 1,123 controls on the susceptibility of IL-17A G197A and C1249T polymorphisms to gastric cancer, respectively. Significant association was observed between IL-17A G197A polymorphism and gastric cancer risk, particularly among Asians. The status of H. pylori infection and smoking did not influence this association. In addition, the IL-17A C1249T polymorphism did not confer a risk effect on gastric carcinogenesis. The pooled results were not materially altered by sensitivity analysis. We firstly show that the polymorphism of IL-17A G197A but not C1249T is a risk factor for gastric cancer.

Role of IL-17F T7488C polymorphism in carcinogenesis: a meta-analysis

Previous case-control studies on the association of interleukin-17F (IL-17F) T7488C polymorphism and cancer risk have yielded conflicting and inconclusive findings. We performed a meta-analysis by pooling all currently available data to acquire a more precise estimation of the association. A comprehensive literature screening from the PubMed, Embase, Web of Science, and Wanfang databases was performed for eligible publications without language restrictions. The pooled odds ratios (ORs) with corresponding 95 % confidence intervals (95 % CIs) were calculated. According to the inclusion criteria, a total of nine case-control studies with 3,034 cases and 3,694 controls were included. Overall, the pooled ORs showed that IL-17F T7488C polymorphism was associated with neither increased nor decreased risk of cancer. However, the IL-17F T7488C polymorphism exerted risk effect on cancer in population-based case-control studies when stratifying analysis by source of controls (C vs T OR = 1.24, 95 % CI, 1.10-1.40, pooled OR (POR) < 0.001; TC vs TT OR = 1.28, 95 % CI, 1.11-1.48, POR = 0.001; CC + TC vs TT OR = 1.29, 95 % CI, 1.12-1.48, POR < 0.001). Additionally, the variant genotypes of IL-17F T7488C could alter the risk of gastric cancer under the following comparisons (C vs T OR = 1.29, 95 % CI, 1.13-1.47, POR < 0.001; TC vs TT OR = 1.35, 95 % CI, 1.14-1.60, POR < 0.001; CC + TC vs TT OR = 1.35, 95 % CI, 1.15-1.58, POR < 0.001). Sensitivity analysis by sequential omission of single study did not materially alter the pooled findings. The present meta-analysis suggests that the IL-17F T7488C polymorphism may modify the risk of cancer, particularly gastric cancer. However, the precise association needs to be elucidated by more individual studies with sufficient statistical power.

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

Interleukin (IL)-17 has been shown to play an important role in the pathogenesis of inflammation and cancer. The IL-17A (-197G/A) and IL-17F (7488T/C) polymorphisms have been extensively investigated with cancer risk, but individually published results have been inconclusive. The aim of this study was to clarify the effects of the IL-17A (-197G/A) and IL-17F (7488T/C) polymorphisms on cancer risk in Asian populations. Relevant studies were identified by searching databases extensively. The association between the IL-17A (-197G/A) and IL-17F (7488T/C) polymorphisms and cancer risk was assessed by odds ratios (ORs) together with their 95% confidence intervals (CIs). A total of 12 articles with adequate information satisfied our inclusion criteria; these included 12 studies, with 4,540 cases and 5,875 controls, of IL-17A (-197G/A) polymorphism and seven studies, with 1,960 cases and 3,226 controls, of IL-17F (7488T/C) polymorphism. In the overall analysis, the IL-17A (-197G/A) polymorphism was significantly associated with increased cancer risk (P<0.05), for all genetic models. However, there was no statistically significant association between IL-17F (7488T/C) and cancer risk (P>0.05), for any genetic models. Furthermore, stratification by cancer type revealed a significant correlation between the IL-17A (-197G/A) polymorphism and cancer risk for all cancer types. When stratified by source of controls, a significant correlation was observed between the IL-17A (-197G/A) polymorphism and cancer risk in the population-based control subgroup but not in hospital-based control subgroup. In conclusion, our meta-analysis provides evidence that the IL-17A (-197G/A) polymorphism might be associated with cancer risk, while no evidence suggested a significant association between IL-17F (7488T/C) polymorphism and cancer risk.

Significant association between interleukin-17A polymorphism and colorectal cancer

Interleukin (IL) 17A is an inflammatory cytokine expressed by Th 17 cells and plays a role in tissue inflammation by inducing release of proinflammatory and neutrophil-mobilizing cytokines. We have investigated the association between colorectal cancer and polymorphisms of IL17A (rs2275913. G197A). The study was performed in 241 subjects (102 with colorectal cancer and 139 healthy controls). Genotypes were determined by fluorescent-based restriction fragment length polymorphism method. The association between the molecular features at the gene in relation to tumor and patient clinical characteristics was analyzed. There was a significant difference between the genotype frequencies of IL17A G197A of control subjects (GG 68.34 % and GA + AA 31.65 %) and patients with colorectal cancer (GG 47.05 % and GA + AA 52.94 %) (p = 0.001 with odds ratio (OR) 2.45 (1.43-4.11)). IL17A G197A polymorphism is particularly associated with colon cancer. Indeed, the IL17A GG genotype could be considered as a protective factor against colon cancer (p = 0.00001) with OR 3.77 (2.04-6.99). We have noted a significant association of IL17A G197A polymorphism not only with tumor localization (p = 0.003) but also with tumor differentiation (p = 0.0005) in CRC patients. We have also showed a significant association of G197A variant with an increased risk of advanced stage (p = 0.005). Our result suggests that the A allele of IL17A gene is involved in susceptibility to colorectal cancer and is associated with clinical features as tumor location, tumor differentiation, and TNM stage. IL17A polymorphism may serve as biomarker of disease location and progression.

Significant association between IL23R and IL17F polymorphisms and clinical features of colorectal cancer

Th17cells are involved in inflammatory and autoimmune diseases. These cells may be involved in pathological processes mainly producing pro-inflammatory cytokines. Recently, it was shown that the IL23/IL17 pathway plays an important role in the development of inflammatory bowel disease. In general, genes encoding cytokines are genetically polymorphic and polymorphisms in genes IL23R el IL17F were shown associated with susceptibility to Crohn's disease and ulcerative colitis which in their turn are considered as risk factors for developing colorectal cancer (CRC). Our approach is to study IL17F and IL23R polymorphisms as risk factor associated with CRC in the Tunisian population in patients and healthy controls. Interesting, we noted a significant association between IL17F and IL23R polymorphisms and tumor location (p=0.0001 and p=0.049, respectively), tumor histology (p=0.007 and p=0.049, respectively) and tumor architecture (p=0.0000000001 and p=0.07, respectively) in CRC patients. We also showed a significant association of IL17F variant with an increased risk of TNM stage III/IV (p=0.007), showing an increased risk of advanced stage. Finally, we observed a positive link between IL17F polymorphism and CRC patients with lymph nodes (p=0.0000000001) and metastasis (p=0.00000009). However, we found no evidence to support a significant association between IL17F and IL23R polymorphisms and colorectal cancer susceptibility. Our findings suggest that IL17F and IL23R polymorphisms were significantly associated with clinical features variables. The IL17F cytokine appear to be involved in the control of tumor growth and invasion of gastrointestinal tumors. IL17 and IL23 polymorphisms or those of their receptors as important determinants of susceptibility to colorectal cancer are still subject to questioning.