IL-17 gene polymorphism is associated with susceptibility to gastric cancer

Associations of IL-4, IL-4R, IL-17A, and IL-17F Polymorphisms with Colorectal Cancer Risk: A Meta-Analysis, Meta-Regression, and Trial Sequential Analysis

Both interleukin (IL)-4 and IL-17 polymorphisms may be involved in the pathogenesis and progression of colorectal cancer (CRC). Herein, we designed a meta-analysis to assess the associations between IL-4, IL-4R, IL-17A, and IL-17F polymorphisms and CRC risk. Scopus, Web of Science, Cochrane Library, and PubMed databases were searched to retrieve articles published until October 21, 2021. We used crude odds ratio (OR) and 95% confidence interval assessing the association of the polymorphisms and CRC risk in 5 genetic models. Trial sequential analysis for the primary analyses was used to control random errors. Twenty-three studies (8: IL-4 rs2243250, 4: IL-4R rs1801275, 5: IL-17A rs2275913, and 6: IL-17F rs763780) were involved in the meta-analysis. The pooled OR (P-value) for the association between IL-4 rs2243250 polymorphism and the CRC risk was 1.11 (0.08), 1.27 (0.12), 1.07 (0.37), 1.09 (0.17), and 1.22 (0.12), for IL-4R rs1801275 polymorphism was 0.71 (0.18), 1.05 (0.76), 0.86 (0.37), 0.87 (0.41), and 0.69 (0.39), for IL-17A rs2275913 polymorphism was 1.83 (0.0003), 1.73 (0.06), 1.47 (<0.001), 1.61 (0.001), and 1.42 (0.15), and for IL-17F rs763780 polymorphism was 1.07 (0.48), 5.33 (0.02), 1.08 (0.49), 1.08 (0.47), and 8.42 (0.002) in allelic, homozygous, heterozygous, recessive, and dominant models, respectively. The G allele and GA genotype of IL-17A rs2275913 polymorphism and the CC genotype of IL-17F rs763780 polymorphism had an elevated risk in CRC cases. The ethnicity and genotyping method, sample size, control, and publication year were effective factors on the pooled results.

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.

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.

Assessment of an onco-sexology support and follow-up program in cervical or vaginal cancer patients undergoing brachytherapy

PURPOSE

Women's sexual health and wellbeing with cervical or vaginal cancer may be largely affected by complications from external beam radiotherapy (EBRT) and utero-vaginal brachytherapy (BT), of which vaginal stenosis is the main complication. The objective of this study was to assess the impact of support by a nurse sexologist on sexuality, vaginal side-effects, and the quality of clinical follow-up in patients treated with brachytherapy for cervical or vaginal cancer.

METHODS

We performed a retrospective study of the sexuality of women treated for cervical or vaginal cancer. Data from patients with cervical or vaginal cancer who underwent brachytherapy between 2013 and 2017 were collected at Institut Universitaire de Cancer de Toulouse-Oncopôle (IUCT-Oncopôle). Patients were divided into two groups: group A (intervention group) received support from a nurse sexologist and group B (control group) did not. The chi-square test and a logistic multivariate model were used for data analysis.

RESULTS

A total of 156 patients were included in this study, including 57.7% who were followed by a nurse sexologist. We observed low compliance in using vaginal dilators after brachytherapy and/or radiotherapy over time regardless of the group, and patients' sexual activity was inadequately addressed. Information regarding the resumption of sexuality 2 months after treatment was missing in 1.1% of patients in group A and in 36.4% of patients in group B. Multivariate analysis showed that patients in group A had a lower risk of developing vaginal stenosis with OR _crude = 0.5 (95% CI = 0.25-0.92) and OR _adj. = 0.5 (95% CI = 0.26-1.09) compared with those in group B.

CONCLUSION

This retrospective study highlights the lack of information collected by physicians during follow-up concerning the sexuality of patients with cervical or vaginal cancer treated by EBRT and BT. The support offered by nurse sexologists in improving patients' sexual activity and reducing their physical side-effects such as vaginal stenosis is likely to be beneficial. A prospective study is currently being conducted to validate the present findings.

Alcohol consumption and risk of stomach cancer: A meta-analysis

Stomach cancer is one of the most common cancers in the world. The relationship between alcohol consumption and the risk of stomach cancer remains unclear. Epidemiology studies investigating this relationship have shown inconsistent findings. A meta-analysis was performed to explore the association between alcohol consumption and increased stomach cancer risk. Eighty-one epidemiology studies, including 68 case-control studies and 13 cohort studies, were included in this study. A significant association was found between alcohol consumption and increased risk of stomach cancer (OR = 1.20, 95% CI 1.12-1.27). To explore the source of the significant heterogeneity (p < 0.05, I² = 86%), analysis was stratified by study type (case-control study and cohort study), control type (hospital-based control and population-based control), gender (male, female, and mix), race (White and Asian), region (United States, Sweden, China, Japan), subsite of stomach cancer, and type of alcohol. The stratified analyses found that region and cancer subsite are major sources of the high heterogeneity. The inconsistent results in different regions and different subsites might be related to smoking rates, Helicobacter pylori infection, obesity, and potential genetic susceptibility. The positive association between drinking and increased risk of stomach cancer is consistent in stratified analyses. The dose-response analysis showed a clear trend that a higher daily intake of alcohol is associated with a higher risk of stomach cancer.

Association of Interleukin-17 gene polymorphisms with susceptibility to chronic hepatitis B virus infection and clearance in Iranian population

Hepatitis B virus (HBV) approximately infects 350 million people. Interleukin-17 (IL-17) as a pro-inflammatory cytokine, have been found to modulate the immune system in infectious and inflammatory diseases. Recently, the influence of genetic changes like single nucleotide polymorphisms (SNP) on expression rate and function of cytokine has been widely investigated. This study was performed to determine any possible association between four IL-17 SNPs (rs2397084, rs763780, rs2275913 and rs10484879) and chronic HBV infection. A total of 466 samples were recruited and studied including 199 chronic patients, 172 healthy controls and 95 spontaneous clearance individuals between genotype and allele frequencies. Genomic DNA was extracted from peripheral blood cells and Polymerase Chain Reaction Restriction Fragment Length Polymorphism (PCR-RFLP) was used to determine the SNPs genotypes. Genotypes frequencies for rs10484879 were 63.8% CC, 31.7% AC, 4.5% AA in chronic group, 54.7% CC, 36.6% AC, 8.7% AA in control and 63.2% CC, 33.7% AC, 5.8% AA in cleared samples. The AC genotype for rs10484879 was significantly associated with a decreased risk of HBV chronicity (Pvalue = 0.031, OR = 2.699, 95%CI: 1.097-6.639). The genotype and allele frequencies of rs2397084, rs763780 and rs2275913 did not show significant difference between chronic HBV patients and healthy controls. Indeed, there is no significant difference between clearance and chronic patient's genotypes in four SNPs. Our results suggest that IL-17A rs10484879 single nucleotide polymorphism genotype is probably associated with susceptibility to HBV chronic infection, while no significant differences in IL-17 rs2397084, rs763780 and rs227591 distribution were found between HBV patients and spontaneous clearance individuals and control participants.

Clinical efficacy of apatinib in treating metastatic gastric cancer and its effect on IL-17

Clinical efficacy of apatinib in treating metastatic gastric cancer and its effect on the levels of serum IL-17 were investigated. A retrospective analysis was performed on 129 patients who had metastatic gastric cancer after first-line chemotherapy and were treated in Xiangyang No. 1 People's Hospital from February 2012 to February 2015. Of these patients, 78 received oral apatinib and were assigned to experimental group; and 51 received oral tegafur-gimeracil-oteracil and were assigned to control group. Clinical efficacy was compared between the two groups, and the levels of serum IL-17 were measured for all the patients. The treatment response rate in the experimental group was 52.56% and in the control group 31.37%. Apparently, the treatment response rate in the experimental group was higher than that in the control group, and the difference was statistically significant (P<0.05). The incidence of adverse drug reactions in the experimental group was significantly lower than that in the control group (P<0.05). The serum level of IL-17 after one course of medication was significantly lower than that before medication in both groups (P<0.05). In comparison between groups, the serum level of IL-17 after one course of medication was clearly lower in the experimental group than that in the control group (P<0.05). Apatinib regimen was demonstrated to have less toxic side-effects in the treatment of metastatic gastric cancer than tegafur-gimeracil-oteracil regimen, indicating that apatinib has favorable safety. In addition, apatinib can downregulate IL-17 expression, which is helpful in attenuating tumor proliferation and improving the clinical efficacy. Therefore, apatinib has potential use in a wide range of clinical applications.

Carcinogenic Helicobacter pylori Strains Selectively Dysregulate the In Vivo Gastric Proteome, Which May Be Associated with Stomach Cancer Progression

Helicobacter pylori is the strongest risk factor for gastric cancer. Initial interactions between H. pylori and its host originate at the microbial-gastric epithelial cell interface, and contact between H. pylori and gastric epithelium activates signaling pathways that drive oncogenesis. One microbial constituent that increases gastric cancer risk is the cag pathogenicity island, which encodes a type IV secretion system that translocates the effector protein, CagA, into host cells. We previously demonstrated that infection of Mongolian gerbils with a carcinogenic cag+H. pylori strain, 7.13, recapitulates many features of H. pylori-induced gastric cancer in humans. Therefore, we sought to define gastric proteomic changes induced by H. pylori that are critical for initiation of the gastric carcinogenic cascade. Gastric cell scrapings were harvested from H. pylori-infected and uninfected gerbils for quantitative proteomic analyses using isobaric tags for relative and absolute quantitation (iTRAQ). Quantitative proteomic analysis of samples from two biological replicate experiments quantified a total of 2764 proteins, 166 of which were significantly altered in abundance by H. pylori infection. Pathway mapping identified significantly altered inflammatory and cancer-signaling pathways that included Rab/Ras signaling proteins. Consistent with the iTRAQ results, RABEP2 and G3BP2 were significantly up-regulated in vitro, ex vivo in primary human gastric monolayers, and in vivo in gerbil gastric epithelium following infection with H. pylori strain 7.13 in a cag-dependent manner. Within human stomachs, RABEP2 and G3BP2 expression in gastric epithelium increased in parallel with the severity of premalignant and malignant lesions and was significantly elevated in intestinal metaplasia and dysplasia, as well as gastric adenocarcinoma, compared with gastritis alone. These results indicate that carcinogenic strains of H. pylori induce dramatic and specific changes within the gastric proteome in vivo and that a subset of altered proteins within pathways with oncogenic potential may facilitate the progression of gastric carcinogenesis in humans.

Associations of the IL-17A rs2275913 and IL-17F rs763780 polymorphisms with the risk of digestive system neoplasms: A meta-analysis

OBJECTIVE

To clarify the associations between the IL-17A rs2275913 and IL-17F rs763780 polymorphisms and the risk of digestive system neoplasms.

METHODS

An internet search was used to identify relevant articles from CNKI, Wanfang, VIP, PubMed, EMBASE and Elsevier up to December 2017. The meta-analysis was performed using Stata 11.0 software.

RESULTS

Twenty-three studies were included. Among these, 21 studies with 6978 cases and 8000 controls were related to IL-17A rs2275913, while 18 studies that included 5073 cases and 6040 controls were related to IL-17F rs763780. The meta-analysis results demonstrated that the overall effects of the two polymorphisms were significantly different (P < 0.05) in the allele model, dominant model, recessive model and codominant model. Subgroup analysis showed that both polymorphisms were significantly associated with susceptibility to gastric cancer but not with hepatocellular carcinoma or colorectal cancer. In the ethnicity analysis, these two polymorphisms were associated with Asian populations but not with Caucasians. Similar results were observed in the hospital-based and population-based control subgroups.

CONCLUSIONS

The IL-17A rs2275913 and IL-17F rs763780 polymorphisms were associated with susceptibility to digestive system neoplasms.

IL-17 and colorectal cancer risk in the Middle East: gene polymorphisms and expression

Background

IL-17 expressed by Th17 cells play a crucial role in tissue inflammation by induction of proinflammatory and neutrophil mobilizing cytokines, and IL-17 polymorphisms are associated with colorectal cancer (CRC).

Objective

We investigated the expression of IL-17 and the association of IL-17 gene polymorphisms with CRC susceptibility in a Middle East population.

Materials and methods

The study included 117 diagnosed CRC patients and 100 age- and gender-matched healthy controls. IL-17A rs2275913 (G197A) and IL-17F rs763780 (T7488C) single nucleotide polymorphisms, mRNA, and protein levels of IL-17A were assessed.

Results

We observed significant association between rs2275913 in IL-17A and susceptibility to CRC (p = 0.016228). The AG and AA genotypes conferred 2-fold and 2.8-fold, respectively, higher risk of developing CRC compared with individuals having GG genotype. Stratification of the data based on gender and age revealed very strong association of CRC with IL17A rs2275913 only in males and “AG” genotype in patients ≤57 years of age at the time of disease diagnosis. The rs763780 in IL-17F was not linked with CRCs in our cohort. Furthermore, IL-17A mRNA expression in CRCs was significantly elevated compared to adjacent normal tissues, particularly in early stages of disease (p = 0.0005). Strong immunoreactivity to IL-17A protein was observed in 70% of early stage relative to 30% of late-stage tumors.

Conclusion

The IL-17A G197A variant may be utilized as a genetic screening marker in assessing CRC risk, and its expression can be used as a biomarker for early detection of CRC in the Saudi 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.

Association between IL-17A G197A polymorphism and gastric cancer risk: an updated meta-analysis based on 6,624 cases and 7,631 controls

Purpose

Previous studies investigating the association between interleukin-17A (IL-17A) G197A polymorphism and gastric cancer risk have provided inconsistent results. We, therefore, conducted this meta-analysis to clarify the association between IL-17A G197A polymorphism and gastric cancer risk.

Methods

We searched PubMed, Excerpta Medica Database, and CNKI databases to identify relevant studies up to June 10, 2017. A total of 16 case-control studies including 6,624 cases and 7,631 controls were identified.

Results

Overall, significant associations between IL-17A G197A polymorphism and gastric cancer risk were observed (A vs G: OR =1.24, 95% CI =1.14–1.36; AA vs GG: OR =1.63, 95% CI =1.35–1.96; GA vs GG: OR =1.12, 95% CI =1.01–1.25; AA+GA vs GG: OR =1.23, 95% CI =1.11–1.35; AA vs GA+GG: OR =1.54, 95% CI =1.27–1.87). Similar associations were also observed in Asian population (A vs G: OR =1.25, 95% CI =1.15–1.37; AA vs GG: OR =1.62, 95% CI =1.33–1.97; GA vs GG: OR =1.16, 95% CI =1.07–1.25; AA+GA vs GG: OR =1.24, 95% CI =1.15–1.33; AA vs GA+GG: OR =1.51, 95% CI =1.23–1.85), in Caucasian population (AA vs GA+GG: OR =2.19, 95% CI =1.40–3.44), and in the hospital-based controls’ subgroup (A vs G: OR =1.30, 95% CI =1.17–1.45; AA vs GG: OR =1.81, 95% CI =1.46–2.25; AA+GA vs GG: OR =1.27, 95% CI =1.12–1.43; AA vs GA+GG: OR =1.71, 95% CI =1.34–2.18).

Conclusions

The current meta-analysis suggests that IL-17A G197A polymorphism might enhance gastric cancer risk.

IL-17 Gene Rs3748067 C>T Polymorphism and Gastric Cancer Risk: A Meta-analysis

OBJECTIVE

The purpose of this study was to investigate the correlation between Interleukin 17 (IL-17) gene rs3748067 C>T polymorphism and gastric cancer risk through pooling the open published data.

METHOD

Case-control or cohort studies relevant to IL-17 gene rs3748067 C>T polymorphism and gastric cancer susceptibility were systematic searched for in the databases of CNKI, Pubmed, Medline, Embase and Web of science. The association between IL-17 gene rs3748067 C>T polymorphism and gastric cancer risk were expressed with an odds ratio(OR) and 95% confidence interval (95% CI). Statistical heterogeneity across the studies was evaluated by I2 test. Publication bias was evaluated by Begg's funnel plot and Egger's line regression test.

RESULTS

Finally, seven case-control studies were included in our present study. Because of the statistical heterogeneity among the included studies for the aspects of dominant (TT+CT vs CC), recessive (TT vs CT+CC) and homozygous genetic model (TT vs CC), the data was pooled by random effect model. The pooled ORs were OR=0.99 (95% CI: 0.65-1.52), OR =1.23 (95% CI: 0.73-2.06 ) and OR=1.14 (95% CI: 0.58-2.27) for dominant, recessive and homozygous genetic model respectively. The pooled data indicated no correlation between IL-17 gene rs3748067 C>T polymorphism and gastric cancer risk. Significant publication bias was found in the dominant genetic model (p<0.05), but not in recessive and homozygous genetic model (p>0.05).

CONCLUSION

Based on the present evidence, there was no correlation between IL-17 gene rs3748067 C>T polymorphism and gastric cancer susceptibility in all genetic model. However, for the small sample size, significant heterogeneity and publication bias, the conclusion should be further evaluated through well designed case-control or cohort studies.

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.

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

Interleukin-17 plays a crucial role in inflammation-related carcinogenesis. We hypothesize that genetic variants in IL-17 are associated with gastric cancer (GCa) risk, and we genotyped five potentially functional single nucleotide polymorphisms (SNPs) (rs1974226 G > A, rs2275913 A > G, rs3819024 A > G, rs4711998 A > G, and rs8193036 C > T) of IL-17 in 1121 GCa patients and 1216 cancer-free controls in an eastern Chinese population. Logistic regression analysis was used to calculate odds ratios (OR) and 95% confidence intervals (CI). Meta-analysis and genotype-mRNA expression correlation were performed to further validate positive associations. We found that an increased GCa risk was independently associated with rs1974226 (adjusted OR = 2.60, 95% CI = 1.27-5.32 for AA vs. GG + GA) and rs2275913 (adjusted OR = 1.33, 95% CI = 1.03-1.72 for GA + AA vs. GG), while a decreased GCa risk was independently associated with rs3819024 (adjusted OR = 0.72, 95% CI = 0.54-0.96 for GG vs. AA + AG). Additional meta-analyses confirmed the observed risk association with rs2275913. We also found that two IL-17 haplotypes (G-G-G-A-C) and (A-G-G-A-C) (in the order of rs1974226, rs2275913, rs3819024, rs4711998 and rs8193036) were associated with a reduced GCa risk (adjusted OR = 0.64, 95% CI = 0.46-0.89 and adjusted OR = 0.38, 95% CI = 0.17-0.81, respectively). However, the expression Quantitative Trait Locus (eQTL) analysis for the genotype-phenotype correlation did not find mRNA expression changes associated with either the genotypes. In conclusions, genetic variants of IL-17 are likely to be associated with risk of GCa, and additional larger studies with functional validation are needed to explore the molecular mechanisms underlying the observed associations.

IL-17A Levels in the Sera of Patients with Gastric Cancer Show Limited Elevation

BACKGROUND

Inflammation plays a major role in the development and progression of gastric and other gastrointestinal tumors. The IL-17 family of cytokines has been under investigation as targets of immunotherapy.

MATERIALS AND METHODS

We investigated the levels of IL-17A inflammatory cytokine in the sera of 57 patients with gastric cancer (GC) and 90 healthy age/sex matched controls using ELISA methods.

RESULTS

In only 5 (8.8%) of the patients' sera was IL-17A detectable. No IL-17A was apparent in the sera of healthy controls. The maximum concentration of IL-17A in patients was 7.004 pg/ml. Vascular and lymphatic invasions were only seen in one of the 5 positive cases. Although all of them were in the age group >60 years, no correlation was seen between age and IL-17A level. These results are somewhat different from our findings for colorectal cancer (CRC) in the same population.

CONCLUSIONS

It is possible that the inflammopathology of CRC and GC are rather different, at least in Fars, a southern province of Iran.

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.