Associations of genotypes and haplotypes of IL-17 with risk of gastric cancer in an eastern Chinese population

Involvement of IL17A and IL17RA variants in interleukin-17A levels and disease activity in ulcerative colitis

Ulcerative colitis (UC) is characterized by chronic inflammation of the large intestine with involvement of Th17 cells and interleukin (IL)-17A. The role of IL17A and IL17A receptor (IL17RA) variants in pathophysiology of UC still remains inconclusive. The aim was to evaluate the association between IL17A and IL17RA variants with susceptibility, IL-17A plasma levels, and endoscopic activity in UC. The study included 104 patients with UC and 213 controls. Patients were divided according to endoscopic activity (remission/mild and moderate/severe). The IL17A rs3819024 A>G and rs3819025 G>A, and IL17RA rs2241043 C>T, rs2241049 A>G, and rs6518661 G>A variants were genotyped using real time polymerase chain reaction. IL-17A plasma levels were determined using immunofluorimetric assay. Neither IL17A nor IL17RA variants were associated with UC susceptibility. The IL17A rs3819024 AG genotype was associated to high levels of IL-17 only in patients. Patients with the G allele of IL17RA rs2241049 showed 2.944 more chance of developing moderate/severe disease. The haplotype analysis showed that IL17RA rs2241049 and rs6518661 was not associated with UC susceptibility and haplotypes constituted with G allele of these variants were not associated with disease severity (p = 0.09). In conclusion, the IL17A rs3819024 AG genotype was associated with elevated IL-17A plasma levels in patients with UC but not in controls and the IL17RA rs2241049 AG+GG genotypes were associated to severity of UC. These results suggest a possible hidden interaction between the IL17A rs3819024 variant and other genetic, environmental, and epigenetic factors in the IL-17A expression that is present only in patients with UC.

Relationship between IL-17, TNF-α, IL-10, IFN-γ, and IL-18 polymorphisms with the outcome of hepatitis B virus infection in the Turkish population

OBJECTIVE

Hepatitis B virus is a global threat that can lead to liver cirrhosis and hepatocellular carcinoma. For the treatment of chronic hepatitis B virus, polymorphisms might be an option for gene treatments. This study aimed to investigate the effects of IL-17, TNF-α, IL-10, IFN-γ, and IL-18 gene polymorphisms on hepatitis B virus infection in the Turkish population.

METHODS

The genotypes and allele distribution of 75 patients exposed to hepatitis B virus and 50 healthy control individuals were analyzed. The real-time polymerase chain reaction method was used for identification.

RESULTS

A correlation was observed between susceptibility to hepatitis B virus infection and IL-17 Exon 3/3'UTR (rs1974226) C, IL-17 Exon 3 (rs763780) A, IL-18 (-607) (rs1946518) A alleles, and IL-17 Exon 3 (rs763780) AA genotype (p=0.006, p=0.009, p=0.025, and p=0.008, respectively). Furthermore, IL-18 (-137) (rs187238) TT genotype and TNF-α-308 (rs1800629) G and A alleles, were associated with protection against hepatitis B virus infection (p=0.0351 and p=0.032, respectively).

CONCLUSION

This study demonstrated that TNF-α (-308), IL-17 (Exon 3/3' UTR), IL-17 (Exon 3), and IL-18 (-607) polymorphisms are associated with hepatitis B virus infection. Therefore, these may serve as potential therapeutic targets for chronic viral hepatitis in the Turkish population.

Helicobacter pylori Immune Response in Children Versus Adults

H. pylori is perhaps the most prevalent human pathogen worldwide and infects almost half of the world's population. Despite the decreasing prevalence of infection overall, it is significant in developing countries. Most infections are acquired in childhood and persist for a lifetime unless treated. Children are often asymptomatic and often develop a tolerogenic immune response that includes T regulatory cells and their products, immunosuppressive cytokines, such as interleukin (IL)-10, and transforming growth factor-β (TGF-β). This contrasts to the gastric immune response seen in H. pylori-infected adults, where the response is mainly inflammatory, with predominant Th1 and Th17 cells, as well as, inflammatory cytokines, such as TNF-α, IFN-γ, IL-1, IL-6, IL-8, and IL-17. Therefore, compared to adults, infected children generally have limited gastric inflammation and peptic ulcer disease. H. pylori surreptitiously subverts immune defenses to persist in the human gastric mucosa for decades. The chronic infection might result in clinically significant diseases in adults, such as peptic ulcer disease, gastric adenocarcinoma, and mucosa-associated lymphoid tissue lymphoma. This review compares the infection in children and adults and highlights the H. pylori virulence mechanisms responsible for the pathogenesis and immune evasion.

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.

The Roles of IL-17, IL-21, and IL-23 in the Helicobacter pylori Infection and Gastrointestinal Inflammation: A Review

Although millions of people have been infected by Helicobacter pylori (H. pylori), only a small proportion of infected individuals will develop adverse outcomes, ranging from chronic gastritis to gastric cancer. Advanced development of the disease has been well-linked with chronic inflammation, which is significantly impacted by the adaptive and humoral immunity response. From the perspective of cellular immunity, this review aims to clarify the intricate axis between IL-17, IL-21, and IL-23 in H. pylori-related diseases and the pathogenesis of inflammatory gastrointestinal diseases. CD4⁺ helper T (Th)-17 cells, with the hallmark pleiotropic cytokine IL-17, can affect antimicrobial activity and the pathogenic immune response in the gut environment. These circumstances cannot be separated, as the existence of affiliated cytokines, including IL-21 and IL-23, help maintain Th17 and accommodate humoral immune cells. Comprehensive understanding of the dynamic interaction between molecular host responses in H. pylori-related diseases and the inflammation process may facilitate further development of immune-based therapy.

Interleukin-17 haplotyping predicts hepatocellular carcinoma in sofosbuvir, pegylated interferon-alpha-2a & ribavirin treated chronic hepatitis C patients

Suspect has been directed towards some direct acting antivirals (DAAs) due to their reported association with hepatocellular carcinoma (HCC) development in chronic hepatitis C (CHC) patients. The mechanisms behind HCC development, following CHC treatment, were not well understood and may be linked to genetic variabilities in different patients which affect several cytokine productions involved in angiogenesis and inflammation. Of these variabilities, is the genetic polymorphisms in the interleukin-17 (IL-17) A receptor gene. Being an important pleiotropic cytokine, this study aimed to investigate the association between haplotypes in IL-17A receptor rs2275913 and rs3819024 and development of HCC in CHC patients treated with either triple therapy (sofosbuvir (SOF), pegylated interferon-alpha-2a (Peg-IFNα-2a) & ribavirin(RBV)) or with dual therapy (Peg-IFNα-2a&RBV). A cohort of 100 CHC patients was recruited in this study. Samples were tested for single nucleotide polymorphism (SNPs) in IL-17A receptor (rs2275913 and rs3819024) using TaqMan Genotyping assay. Our results showed that the presence of G-G haplotype in IL-17A (rs2275913& rs3819024) is inversely associated with HCC development in patients receiving triple therapy. While, high serum AFP levels are directly associated with HCC development in patients receiving triple therapy. However, in patients receiving dual therapy, HCC development was only associated with high serum alpha fetoprotein (AFP) levels and was not correlated to any specific allele in our studied SNPs. Such results highlight the importance of IL17A receptor gene haplotyping in the prediction of HCC development in patients receiving triple therapy. These results will aid in performing tailored, personalized strategy for CHC treatment.

Association of Polymorphisms in Cytokine genes with susceptibility to Precancerous Lesions and Cervical Cancer: A systematic review with meta-analysis

Objectives: This study investigated the relationship between single-nucleotide polymorphisms (SNPs) in cytokine genes and the susceptibility to Squamous Intraepithelial Lesions (SIL), cervical cancer and HPV infection through a systematic review with meta-analysis. To verify the effect of SNPs, we also analyzed the transcription factor binding affinity using bioinformatics tools.Methods: Seven electronic databases (MEDLINE, Scielo, BIREME, PubMed, Scopus, Web of Science and Science Direct) were searched for case-control studies.Results: A total of 35 relevant case-control studies were meta-analyzed, including 7 cytokine genes and 15 SNPs. SNPs in IL-17A (rs2275913, rs3748067); IL-17 F (rs763780); IL-12A (rs568408); IL-12B (rs3212227); TNFA (rs1800629, rs361525); IL-1B (rs16944); IL-6 (rs1800795); IL-10 (rs1800896) genes were associated with increased risk for cervical cancer. No association was observed between meta-analyzed polymorphisms and SIL. Additional bioinformatics analysis suggested a possible transcriptional regulation pathway of the TNFA and IL-10 genes through the MZF1 (TNFA -308 G > A and IL-10 - 1082A>G) and ZNF263 (TNFA -238 G > A) transcription factors binding.Conclusion: Overall, 10 SNPs in cytokine genes were associated with increased risk for cervical cancer. Therefore, in our meta-analysis, these SNPs demonstrated to be potential biomarkers for predicting or identifying cases of high risk for SIL and cervical cancer.

Interleukin-17A polymorphisms predict the response and development of tolerance to FOLFOX chemotherapy in colorectal cancer treatment

Polymorphic variants in IL-17A gene were differentially associated with colorectal cancer (CRC) susceptibility but their link with response and toxicity to CRC treatment have not yet been evaluated. We investigated association between seven IL-17A variants with the response and toxicity to CRC treatment in 294 patients with CRC. IL-17A genotyping was done by real-time PCR. MAF of rs3748067 was significantly higher in CRC cases resistant to FOLFOX treatment (R+) than non resistant (R-). Significantly higher rs3804513 MAF was noted in R+ versus R- colon cancer (CC). Higher rs2275913 and rs10484879, and reduced rs3804513 MAF were seen in rectal cancer (RC) tolerant to FOLFOX (T+) compared to (T-) patients. Strong association of rs3819025, rs3804513, and rs7747909 was found with tolerance to RC treatment. rs3748067 was associated with FOLFOX tolerance in CC but not RC. Significant higher frequency of AGGCAGG and GAGCAGG haplotypes was seen among R + CC, thus assigning non-favorable nature to these haplotypes. Higher and lower frequencies of GAGTAAG and AGGCTGA haplotypes, respectively, were observed in T + RC, thereby assigning FOLFOX-tolerant and non-tolerant nature to these haplotypes. The obtained results suggest that IL-17A variants and haplotypes may be a target for future management of CRC treatment.

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.

The association of IL-17A polymorphisms with IL-17A serum levels and risk of ischemic stroke

The aim of our study was to investigate the association of interleukin-17A (IL-17A) polymorphisms with IL-17A serum levels and risk of ischemic stroke (IS) in a Chinese population. 392 IS patients and 443 controls were included in this study. The polymorphisms of IL-17A gene were determined by Snapshot SNP genotyping assay and DNA sequencing. Serum IL-17A levels were measured by enzyme-linked immunosorbent assay (ELISA). We found that the G allele, GA and GG genotypes, and GA/GG vs. AA model of rs2275913 polymorphism were associated with increased risk of IS even after adjusted by clinical characters such as age, gender and diabetes (G vs. A: OR=1.27, 95% CI, 1.05∼1.54, P=0.014; GA vs. AA: OR=1.72, 95% CI, 1.05∼2.81, P=0.032; GG vs. AA: OR=1.99, 95% CI, 1.08∼3.67, P=0.028; GA/GG vs. AA: OR=1.78, 95% CI, 1.11∼2.86, P=0.017). Serum IL-17A levels were increased in IS patients compared with controls (P<0.01). Individuals carrying rs2275913 GA or GG genotype present higher serum IL-17A levels compared with the rs2275913AA genotype in the IS group (P<0.01). In conclusion, this is the first study reporting the rs2275913 polymorphism as a risk factor for IS, which may be partly explained by influencing the levels of IL-17A cytokine.