Interleukin-1 gene polymorphisms and gastric cancer risk in a high-risk Italian population

Association between interleukin-1 receptor antagonist (IL-1ra) VNTR, gene polymorphism and breast cancer susceptibility in Iranian population: Experimental and web-based analysis

Breast cancer is one of the leading causes of cancer mortality. Growing evidence indicates that interleukins and its polymorphisms are involved in the pathogenesis of breast cancer. Variable number of tandem repeat (VNTR) polymorphism can affect transcription rate, mRNA stability and also the resulting protein expression and activity. Hence, present study aimed to assess the possible association between interleukin-1 receptor antagonist (IL-1Ra) VNTR polymorphism, and breast cancer susceptibility in Iranian population. A total of 300 Iranian individuals, 150 breast cancer patients and 150 age-matched healthy women, were included in this study. DNA extracted by salting out method and genotyping was done using the polymerase chain reaction. The frequency of the allele 2(5% vs. 22%) and the 2/2 genotype (22% vs. 46%) of IL-1Ra VNTR polymorphism was significantly higher in healthy control compared to breast cancer patient: therefore, A2 allele may play a protective role against breast cancer and its progression (p = .0001 and OR = 0.105, 95% CI: [0.044-0.248]). The allele 2 and 2/2 genotype of the IL-Ra VNTR polymorphism can be a protective factor against breast cancer susceptibility.

Role of IL-1β rs1143634 (+3954C>T) polymorphism in cancer risk: an updated meta-analysis and trial sequential analysis

OBJECTIVE

Oxidative stress caused by the pro-inflammatory cytokine interleukin (IL)-1β has been widely investigated for cancer risk. In this study, we focused on the role of IL-1β rs1143634 polymorphism to reveal its impact on cancer development.

METHODS

Related studies with fixed inclusion criteria were selected from electronic databases to May 2021. This meta-analysis was performed with odds ratios and 95% confidence intervals. Heterogeneity, publication bias and sensitivity analyses were also conducted. Trial sequential analysis (TSA) and in-silico gene expression analysis were performed.

RESULTS

Forty-four case-control studies involving 18,645 patients with cancer and 22,882 controls were included. We observed a significant association of this single nucleotide polymorphism with overall cancer risk in the codominant model 3 (1.13-fold), recessive model (1.14-fold) and allelic model (1.08-fold). Subgroup analysis revealed that rs1143634 elevated the risk of gastric cancer, breast cancer and multiple myeloma. In addition, Asian and mixed populations and hospital-based controls had a significantly higher risk of cancer development. TSA confirmed our findings.

CONCLUSION

Our meta-analysis revealed that the presence of IL-1β rs1143634 polymorphism increases the risk of cancer development. Among polymorphism carriers, the Asian population has a higher risk than other ethnic populations.This meta-analysis was registered retrospectively at INPLASY (https://inplasy.com/, INPLASY2021100044).

Association study indicates combined effect of interleukin-10 and angiotensin-converting enzyme in basal cell carcinoma development

Cytokines involved in inflammatory and immune response have been associated with risk for development of basal cell carcinoma (BCC). In this study, three functional DNA polymorphisms affecting gene expression were investigated in 54 BCC patients and 111 healthy controls: interleukin-1b (IL-1b) +3953C/T, interleukin-10 (IL-10) - 1082G/A and angiotensin-converting enzyme (ACE) insertion/deletion (I/D) polymorphisms. Significant increase of the variant alleles was observed in IL-10 - 1082G (P = 0.019) and in ACE D (P = 0.003) in BCC patients in comparison to controls. Multivariate logistic regression models evaluated the contribution of homozygous and heterozygous variant polymorphisms to the risk for BCC development. The studied polymorphisms influencing the expression of IL-10 and ACE genes were recognized as potential predictive factors for BCC. These findings suggest a possible molecular mechanism leading to BCC development that is likely to involve the activation of angiotensin receptors in combination with increased plasma levels of IL-10 in patients.

Unveiling the Crucial Role of Type IV Secretion System and Motility of Helicobacter pylori in IL-1β Production via NLRP3 Inflammasome Activation in Neutrophils

Helicobacter pylori is a gram-negative, microaerophilic, and spiral-shaped bacterium and causes gastrointestinal diseases in human. IL-1β is a representative cytokine produced in innate immune cells and is considered to be a key factor in the development of gastrointestinal malignancies. However, the mechanism of IL-1β production by neutrophils during H. pylori infection is still unknown. We designed this study to identify host and bacterial factors involved in regulation of H. pylori-induced IL-1β production in neutrophils. We found that H. pylori-induced IL-1β production is abolished in NLRP3-, ASC-, and caspase-1/11-deficient neutrophils, suggesting essential role for NLRP3 inflammasome in IL-1β response against H. pylori. Host TLR2, but not TLR4 and Nod2, was also required for transcription of NLRP3 and IL-1β as well as secretion of IL-1β. H. pylori lacking cagL, a key component of the type IV secretion system (T4SS), induced less IL-1β production in neutrophils than did its isogenic WT strain, whereas vacA and ureA were dispensable. Moreover, T4SS was involved in caspase-1 activation and IL-1β maturation in H. pylori-infected neutrophils. We also found that FlaA is essential for H. pylori-mediated IL-1β production in neutrophils, but not dendritic cells. TLR5 and NLRC4 were not required for H. pylori-induced IL-1β production in neutrophils. Instead, bacterial motility is essential for the production of IL-1β in response to H. pylori. In conclusion, our study shows that host TLR2 and NLRP3 inflammasome and bacterial T4SS and motility are essential factors for IL-1β production by neutrophils in response to H. pylori.

Association of Interleukin-10 Genotypes and Oral Cancer Susceptibility in Selected Malaysian Population: A Case- Control Study

Background:

Interleukin-10 (IL10) genotypes have been closely correlated to the susceptibility for oral squamous cell carcinoma. More than half of oral cancers in the world occur in Asia with estimated 168,850 new cases were diagnosed in this geographical region alone. Considering the rising numbers of oral cancer cases in Malaysia, association of IL10 A1082G gene polymorphism was correlated.

Methodology:

41 oral squamous cell carcinoma (OSCC) cases and 48 healthy controls of comparable age, gender, and with habits like smoking, alcohol consumption and betel quid chewing were selected. In this case-control study, samples were collected from the Oral Cancer Research and Coordinating Centre (OCRCC), Faculty of Dentistry, University of Malaya, Malaysia. Genotyping conditions were evaluated by polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP). The PCR products were subjected to digestion by MnlI enzyme (NEB, UK) to screen for the IL10 A-1082G. Digested DNA products were analyzed by electrophoresis on 4% (w/v) agarose gel, stained with ethidium bromide and imaged under UV illumination. Chi-square test and Fisher’s Exact test were used in statistical analysis.

Results:

AG genotypes were present in 81.3% and 86.0% of healthy control and OSCC cases respectively (OR=0.468, 95% CI=0.133-1.653). No significant association was found between IL10 A1082G polymorphism with risk habits, clinico-pathological parameters and 5-years overall survival. The findings also show no significant correlation between the IL10 genotype and features of OSCC within the case group as measured by tumor size, lymph node involvement, stage, invasive front, grading, depth, pattern of invasion.

Conclusion:

This study suggests that functional polymorphism AG of IL10 A1082G may have no influence with OSCC susceptibility. However, further investigation with larger sample sizes can be conducted to provide additional evidence to support the lack of association of IL10 A1082G polymorphism in oral cancer.

Network pharmacology-based strategy to investigate pharmacological mechanisms of Zuojinwan for treatment of gastritis

BACKGROUND

Zuojinwan (ZJW), a classic herbal formula, has been extensively used to treat gastric symptoms in clinical practice in China for centuries. However, the pharmacological mechanisms of ZJW still remain vague to date.

METHODS

In the present work, a network pharmacology-based strategy was proposed to elucidate its underlying multi-component, multi-target, and multi-pathway mode of action against gastritis. First we collected putative targets of ZJW based on TCMSP and STITCH databases, and a network containing the interactions between the putative targets of ZJW and known therapeutic targets of gastritis was built. Then four topological parameters, "degree", "betweenness", "closeness", and "coreness" were calculated to identify the major targets in the network. Furthermore, the major hubs were imported to the Metacore database to perform a pathway enrichment analysis.

RESULTS

A total of 118 nodes including 59 putative targets of ZJW were picked out as major hubs in terms of their topological importance. The results of pathway enrichment analysis indicated that putative targets of ZJW mostly participated in various pathways associated with anti-inflammation response, growth and development promotion and G-protein-coupled receptor signaling. More importantly, five putative targets of ZJW (EGFR, IL-6, IL-1β, TNF-α and MCP-1) and two known therapeutic targets of gastritis (CCKBR and IL-12β) and a link target NF-κB were recognized as active factors involved in the main biological functions of treatment, implying the underlying mechanisms of ZJW acting on gastritis.

CONCLUSION

ZJW could alleviate gastritis through the molecular mechanisms predicted by network pharmacology, and this research demonstrates that the network pharmacology approach can be an effective tool to reveal the mechanisms of traditional Chinese medicine (TCM) from a holistic perspective.

The application of transgenic and gene knockout mice in the study of gastric precancerous lesions

Gastric intestinal metaplasia is a precursor for gastric dysplasia, which is in turn, a risk factor for gastric adenocarcinoma. Gastric metaplasia and dysplasia are known as gastric precancerous lesions (GPLs), which are essential stages in the progression from normal gastric mucosa to gastric cancer (GC) or gastric adenocarcinoma. Genetically-engineered mice have become essential tools in various aspects of GC research, including mechanistic studies and drug discovery. Studies in mouse models have contributed significantly to our understanding of the pathogenesis and molecular mechanisms underlying GPLs and GC. With the development and improvement of gene transfer technology, investigators have created a variety of transgenic and gene knockout mouse models for GPLs, such as H/K-ATPase transgenic and knockout mutant mice and gastrin gene knockout mice. Combined with Helicobacter infection, and treatment with chemical carcinogens, these mice develop GPLs or GC and thus provide models for studying the molecular biology of GC, which may lead to the discovery and development of novel drugs. In this review, we discuss recent progress in the use of genetically-engineered mouse models for GPL research, with particular emphasis on the importance of examining the gastric mucosa at the histological level to investigate morphological changes of GPL and GC and associated protein and gene expression.

Mouse models for gastric cancer: Matching models to biological questions

Gastric cancer is the third leading cause of cancer-related mortality worldwide. This is in part due to the asymptomatic nature of the disease, which often results in late-stage diagnosis, at which point there are limited treatment options. Even when treated successfully, gastric cancer patients have a high risk of tumor recurrence and acquired drug resistance. It is vital to gain a better understanding of the molecular mechanisms underlying gastric cancer pathogenesis to facilitate the design of new-targeted therapies that may improve patient survival. A number of chemically and genetically engineered mouse models of gastric cancer have provided significant insight into the contribution of genetic and environmental factors to disease onset and progression. This review outlines the strengths and limitations of current mouse models of gastric cancer and their relevance to the pre-clinical development of new therapeutics.

Interaction between Helicobacter pylori and host genetic variants in gastric carcinogenesis

Helicobacter pylori (H. pylori) is the definite carcinogen of gastric cancer. H. pylori infection induces chronic inflammation, causes DNA damage and aberrant methylation of genes and these pathways are involved in H. pylori-related gastric carcinogenesis. Polymorphisms of the genes involved in these pathways could alter susceptibility to gastric cancer. In this mini review, we focused on the role of polymorphisms in these genes on the susceptibility to gastric cancer, with a particular emphasis on their possible interactions with H. pylori infection. We found that many studies on this theme did not simultaneously report H. pylori infection and the interactions remained inconclusive.

Interleukin-1B 31 C>T polymorphism combined with Helicobacter pylori-modified gastric cancer susceptibility: evidence from 37 studies

Gastric cancer is one of the most common malignancies worldwide. Interleukin‐1‐beta (IL‐1β) is a pro‐inflammatory cytokine and potent inhibitor of gastric acid secretion. Some studies provided evidence of the association between IL‐1B 31 polymorphism and gastric cancer risk while other studies did not. Therefore, we conducted a comprehensive meta‐analysis to reassess the association. A systematic literature search of the PubMed and EMBASE databases identified 37 studies with 6108 cases and 8980 controls for this meta‐analysis. The crude odd ratios (ORs) and the 95% confidence intervals (CIs) were calculated to evaluate the strength of the association. Meta‐regression was used to determine the major source of heterogeneity across the studies. The pooled analysis did not suggest the significant association of IL‐1B 31 C>T polymorphism with gastric cancer risk. Stratified analysis was performed by ethnicity, source of control, genotype method, and indicated a significantly increased gastric cancer risk associated with IL‐1B 31T variant in the population‐based subgroup (heterozygous model: OR = 1.22, 95% CI = 1.03–1.45). Moreover, stratified analysis by Helicobacter pylori infection status indicated that IL‐1B 31 polymorphism increased gastric cancer risk in infection‐positive subgroup (homozygous model: OR = 1.35, 95% CI = 1.02–1.78; heterozygous model: OR = 1.31, 95% CI = 1.04–1.66; recessive model: OR = 1.29, 95% CI = 1.04–1.61). The study suggested that IL‐1B 31 polymorphism might confer susceptibility to gastric cancer in the presence of H. pylori infection, indicating a gene–environment interaction in gastric carcinogenesis.

Withaferin A Inhibits Helicobacter pylori-induced Production of IL-1β in Dendritic Cells by Regulating NF-κB and NLRP3 Inflammasome Activation

Helicobacter pylori infection is associated with chronic gastritis, peptic ulcer, and gastric cancer. There is evidence that IL-1β is associated with the development of gastric cancer. Therefore, downregulation of H. pylori-mediated IL-1β production may be a way to prevent gastric cancer. Withaferin A (WA), a withanolide purified from Withania somnifera, is known to exert anti-inflammatory and anti-tumor effects. In the present study, we explored the inhibitory activity of WA on H. pylori-induced production of IL-1β in murine bone marrow-derived dendritic cells (BMDCs) and the underlying cellular mechanism. Co-treatment with WA decreased IL-1β production by H. pylori in BMDCs in a dose-dependent manner. H. pylori-induced gene expression of IL-1β and NLRP3 (NOD-like receptor family, pyrin domain containing 3) were also suppressed by WA treatment. Moreover, IκB-α phosphorylation by H. pylori infection was suppressed by WA in BMDCs. Western blot analysis revealed that H. pylori induced cleavage of caspase-1 and IL-1β, as well as increased procaspase-1 and pro IL-1β protein levels, and that both were suppressed by co-treatment with WA. Finally, we determined whether WA can directly inhibit ac tivation of the NLRP3 inflammasome. NLRP3 activators induced IL-1β secretion in LPS-primed macrophages, which was inhibited by WA in a dose-dependent manner, whereas IL-6 production was not affected by WA. Moreover, cleavage of IL-1β and caspase-1 by NLRP3 activators was also dose-dependently inhibited by WA. These findings suggest that WA can inhibit IL-1β production by H. pylori in dendritic cells and can be used as a new preventive and therapeutic agent for gastric cancer.

Helicobacter pylori in gastric carcinogenesis

Gastric cancer still is a major concern as the third most common cancer worldwide, despite declining rates of incidence in many Western countries. Helicobacter pylori (H. pylori) is the major cause of gastric carcinogenesis, and its infection insults gastric mucosa leading to the occurrence of atrophic gastritis which progress to intestinal metaplasia, dysplasia, early gastric cancer, and advanced gastric cancer consequently. This review focuses on multiple factors including microbial virulence factors, host genetic factors, and environmental factors, which can heighten the chance of occurrence of gastric adenocarcinoma due to H. pylori infection. Bacterial virulence factors are key components in controlling the immune response associated with the induction of carcinogenesis, and cagA and vacA are the most well-known pathogenic factors. Host genetic polymorphisms contribute to regulating the inflammatory response to H. pylori and will become increasingly important with advancing techniques. Environmental factors such as high salt and smoking may also play a role in gastric carcinogenesis. It is important to understand the virulence factors, host genetic factors, and environmental factors interacting in the multistep process of gastric carcinogenesis. To conclude, prevention via H. pylori eradication and controlling environmental factors such as diet, smoking, and alcohol is an important strategy to avoid H. pylori-associated gastric carcinogenesis.

Interleukin-1 gene polymorphisms in chronic gastritis patients infected with Helicobacter pylori as risk factors of gastric cancer development

Epidemiological investigations indicated association of the Helicobacter pylori infections with the occurrence of inflammatory conditions of the gastric mucosa and development of chronic gastritis and intestinal type of gastric cancer. IL1A and IL1B genes have been proposed as key factors in determining risk of gastritis and malignant transformation. The aim of this paper was to evaluate association of interleukin-1 gene polymorphisms with chronic gastritis, atrophy, intestinal metaplasia, dysplasia and intestinal type of gastric cancer in H. pylori-infected patients. Patients subjected to analysis represent group of 144 consecutive cases that suffered from dyspepsia with coexisting infection of H. pylori and chronic gastritis, chronic atrophic gastritis, intestinal metaplasia, dysplasia or gastric cancer. Molecular studies involved analysis of –889C>T polymorphism of IL1A gene and +3954C>T polymorphism of IL1B gene. Statistical analysis of association of polymorphism –889C>T of gene IL1A with changes in gastric mucosa showed lack of significance, whereas +3954C>T polymorphism of IL1B gene showed significant association. Frequency of allele T of +3954C>T polymorphism of IL1B gene was higher in group of patients with chronic gastritis, atrophy, intestinal metaplasia, dysplasia or intestinal type of gastric cancer (32.1 %) as compared with population group (23 %), χ² = 4.61 and p = 0.03. This corresponds to odds ratio: 1.58, 95 % CI: 1.04–2.4. Our results indicate that +3954C>T polymorphism of IL1B gene increase susceptibility to inflammatory response of gastric mucosa H. pylori-infected patients and plays a significant role in the development of chronic gastritis, atrophy, intestinal metaplasia, dysplasia and the initiation of carcinogenesis.

Interleukin-1β induced by Helicobacter pylori infection enhances mouse gastric carcinogenesis

Interleukin-1β (Il1b) is considered to be involved in Helicobacter pylori (HP)-induced human gastric carcinogenesis, while the role of its polymorphisms in gastric cancer susceptibility remains controversial. Here, we aimed to clarify the role of HP infection-induced IL1B in gastric inflammation and carcinogenesis using Il1b(-/-) (Il1b-null) mice. In gastric mucosa of the Il1b(+/+) (WT) mice, HP infection induced Il1b expression and severe inflammation. In contrast, in Il1b-null mice, recruitment of neutrophils and macrophages by HP infection was markedly suppressed. In a carcinogenicity test, the multiplicity of gastric tumors was significantly suppressed in theIl1b-null mice (58% of WT; P<0.005). Mechanistically, HP infection induced NF-κB activation both in the inflammatory and epithelial cells in gastric mucosae, and the activation was attenuated in the Il1b-null mice. Accordingly, increased proliferation and decreased apoptosis of gastric epithelial cells induced by HP infection in the WT mice were attenuated in the Il1b-null mice. These results demonstrated that the IL1B physiologically induced by HP infection enhanced gastric carcinogenesis by affecting both inflammatory and epithelial cells.

Glutathione S-transferase polymorphisms (GSTM1, GSTT1 and GSTP1) and their susceptibility to renal cell carcinoma: an evidence-based meta-analysis

Background

The association of the three Glutathione S-transferases (GSTs) polymorphisms (GSTM1, GSTT1 and GSTP1) genotypes with their individual susceptibilities to renal cell carcinoma (RCC) has not been well established. We performed a quantitative meta-analysis to assess the possible associations between the GSTM1, GSTT1 and GSTP1 genotypes and their individual susceptibilities to renal cell carcinoma.

Methods

We systematically searched the PubMed, CNKI and Embase databases to identify the relevant studies. Finally, 11 eligible studies were selected. The pooled odds ratios (ORs) with their 95% confidence intervals (CIs) were used to assess the association between the GSTs polymorphisms and the risk of RCC. Multiple subgroup analyses and quality assessment of the included studies were performed based on the available information.

Results

None of the GSTs polymorphisms had a significant association with the RCC risk. Similar results were found in the subgroup analyses, except for the GSTs polymorphisms in the situations described below. The GSTM1 and GSTT1 active genotypes in subjects exposed to pesticides (GSTM1: OR = 3.44; 95% CI, 2.04–5.80; GSTT1: OR = 2.84; 95% CI, 1.75–4.60), most of the GSTs genotypes in Asian populations (GSTT1: OR = 2.39, 95% CI = 1.63–3.51; GSTP1: Dominant model: OR = 1.50, 95% CI = 1.14–1.99; Additive model: OR = 1.39, 95% CI = 1.12–1.73; AG vs. AA: OR = 1.47, 95% CI = 1.10–1.97; GG vs. AA: OR = 1.82, 95% CI = 1.07–3.09) and the dual null genotype of GSTT1-GSTP1 (OR = 2.84, 95% CI = 1.75–4.60) showed positive associations with the RCC risk.

Conclusion

Our present study provides evidence that the GSTM1, GSTT1 and GSTP1 polymorphisms are not associated with the development of RCC. However, more case-control studies are needed for further confirmation.

Systematic review and meta-analysis on the association between IL-1B polymorphisms and cancer risk

BACKGROUND

Interleukin-1 beta (IL-1β), a pro-inflammatory cytokine, is emerging as a key mediator of carcinogenesis that characterizes host-environment interactions. Epidemiological studies investigating the association between two polymorphisms of IL-1B (-511C/T and +3954C/T) and cancer susceptibility have shown conflicting results. The aim of this study is to derive a more precise estimation of the relationship.

METHODS

Related studies were identified through a systematic literature search of PubMed and Web of Science from their inception to September 15, 2012. Summary odds ratios (ORs) and 95% confidence intervals (CIs) for the IL-1B -511C/T and +3954C/T polymorphisms and cancer risk were calculated. Heterogeneity among studies and publication bias were also tested.

RESULTS

The meta-analysis included 91 case-control studies in 85 publications, 81 studies for the -511C/T (19547 cases and 23935 controls) and 26 studies for the +3954C/T polymorphisms (8083 cases and 9183). The pooled results indicated that IL-1B +3954C/T (dominant model: OR = 1.15, 95% CI: 1.01-1.30) was significantly associated with increased overall cancer risk, especially among hospital-based case-control studies (dominant model: OR = 1.30, 95% CI: 1.02-1.66). As for -511C/T, we observed an inverse relationship in cervical cancer (dominant model: OR = 1.74, 95% CI: 1.35-2.23) and hepatocellular carcinoma (dominant model: OR = 0.68, 95% CI: 0.47-0.99). Moreover, -511C/T was associated with risk of specific subtypes of gastric carcinoma.

CONCLUSION

This meta-analysis suggested that both the IL-1B -511C/T and +3954C/T polymorphisms might modulate cancer susceptibility. Further well-designed studies based on larger sample sizes should be performed to confirm the findings.

IL1 receptor antagonist gene IL1-RN variable number of tandem repeats polymorphism and cancer risk: a literature review and meta-analysis

IL1 receptor antagonist (IL1RA) and IL1beta (IL1β), members of the pro-inflammatory cytokine interleukin-1 (IL1) family, play a potential role against infection and in the pathogenesis of cancers. The variable number of tandem repeats (VNTR) polymorphism in the second intron of the IL1 receptor antagonist gene (IL1-RN) and a polymorphism in exon 5 of IL1B (IL1B+3954C>T, rs1143634) have been suggested in predisposition to cancer risk. However, studies have shown inconsistent results. To validate any association, a meta-analysis was performed with 14,854 cases and 19,337 controls from 71 published case–control studies for IL1-RN VNTR and 33 eligible studies contained 7,847 cases and 8917 controls for IL1B +3954. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated from comparisons to assess the strength of the association. There was significant association between the IL1-RN VNTR polymorphism and the risk of cancer for any overall comparison. Furthermore, cancer type stratification analysis revealed that there were significantly increased risks of gastric cancer, bladder cancer and other cancer groups. Infection status analysis indicated that the H. pylori or HBV/HCV infection and IL1-RN VNTR genotypes were independent factors for developing gastric or hepatocellular cancers. In addition, a borderline significant association was observed between IL1B+3954 polymorphism and the increased cancer risk. Although some modest bias could not be eliminated, this meta-analysis suggested that the IL1-RN VNTR polymorphisms may contribute to genetic susceptibility to gastric cancer. More studies are needed to further evaluate the role of the IL1B+3954 polymorphism in the etiology of cancer.

IL-1 polymorphisms in children with peptic symptoms in South China

BACKGROUND

Polymorphisms of IL-1 gene cluster are reported to be associated with histological changes and IL-1β expression in the gastric mucosa in adults, especially in Helicobacter pylori-infected subjects. As H. pylori infecting adults and children own different virulence genotypes, the aim of this study was to investigate whether IL-1 polymorphisms are risk factors in young children in South China.

MATERIALS AND METHODS

A total of 128 children with peptic symptoms were enrolled in this study. Polymorphisms of IL-1B-511 and IL-1B-31 were identified by dual fluorescence PCR. Variable number of tandem repeat region in IL-1RN was detected by conventional PCR and IL-1β mRNA expression by real-time PCR ddCT assay.

RESULTS

IL-1B-31T and IL-1B-511C were completely linked in this study. Significant differences of IL-1B-511/-31 genotypes were observed among different clinical outcomes (p = .001). The IL-1B-511TT/-31CC was mostly found in the moderate gastritis and the above (severe gastritis or gastric ulcer) groups, with percentage of 60.7%. While no association was observed between IL-1RN genotypes and the gastric mucosal histological changes (p = .128). Also no relationships were found between IL-1 polymorphisms and H. pylori infection or gastric mucosal IL-1β mRNA expression level.

CONCLUSION

Children with IL-1B-511TT/-31CC may have a risk to develop relatively severe gastric mucosal histological changes in South China.

Polymorphisms in inflammatory response genes and their association with gastric cancer: A HuGE systematic review and meta-analyses

To evaluate the association between gastric cancer susceptibility and inflammation-related gene polymorphisms, the authors conducted a series of meta-analyses using a predefined protocol. Genes investigated were those coding for the interleukin (IL) proteins (IL1B, IL1RN, IL8, and IL10) and for tumor necrosis factor-alpha. Gastric cancers were stratified by histologic subtype and anatomic subsite, by Helicobacter pylori infection status, by geographic location (Asian or non-Asian study population), and by a quantitative index of study quality. All published literature and meeting abstracts from the period 1990-2006 were considered. Results consistently supported increased cancer risk for IL1RN2 carriers; the increased risk was specific to non-Asian populations and was seen for intestinal and diffuse cancers, distal cancers, and, to a lesser extent, cardia cancers. Analyses restricted to high-quality studies or H. pylori-positive cases and controls also showed significant associations with both carrier status and homozygosity status. In Asian populations, reduced risk was observed in association with IL1B-31C carrier status. This effect was also observed in analyses restricted to high-quality studies. These results indicate the importance of stratification by anatomic site, histologic type, H. pylori infection, and country of origin. Study quality considerations, both laboratory and epidemiologic, can also affect results and may explain, in part, the variability in results published to date.

Interleukin-1B and interleukin-1 RN polymorphisms and gastric carcinoma risk: a meta-analysis

BACKGROUND AND AIM

We aimed to explore the role of interleukin (IL)-1B cluster gene polymorphisms at positions -511, -31, and +3954 and the receptor IL-1RN variable number tandem repeat polymorphisms in the susceptibility to gastric carcinoma through a systematic review and meta-analysis.

METHODS

Each initially included article was scored for quality appraisal. The desirable data were extracted and registered into databases. Studies that deviated from Hardy-Weinberg equilibrium were excluded. Eighteen studies were ultimately eligible for the meta-analysis of IL1B-511, 21 studies for IL1B-31, 10 studies for IL1B+3954, and 20 studies for IL1RN variable number tandem repeat genetic polymorphisms, respectively. Original groups were collapsed and re-grouping was adopted in line with the most probably appropriate genetic models. Potential sources of heterogeneity were sought out via stratification and sensitivity analyses, and biases across studies were estimated.

RESULTS

The pooled odds ratios (95% confidence intervals, P-value) associated with IL-1B -511 T carriers versus CC genotypes and with RN *2 carriers versus L/L were 1.23 (1.04-1.45, P = 0.015) and 1.26 (1.06-1.51, P = 0.010), respectively, for overall gastric carcinoma; 1.31 (1.04-1.64, P = 0.020) and 1.47 (1.21-1.79, P = 0.000), respectively, for non-cardia gastric cancer; 1.55 (1.05-2.28, P = 0.026) and 1.66 (1.23-2.25, P = 0.001), respectively, for intestinal type gastric carcinoma; and 1.33 (1.04-1.71, P = 0.023) and 1.31 (1.07-1.61, P = 0.010), respectively, in Caucasians for overall gastric carcinoma. The pooled odds ratio (95% confidence interval, P-value) regarding IL-1B-31 CC plus TT versus CT was 0.73 (0.60-0.89, P = 0.002) for intestinal type gastric carcinoma. Genotyping methods and publication time could constitute the sources of heterogeneity across studies. Publication biases were not found.

CONCLUSION

IL-1B -511 T allele and IL-1 RN *2 VNTR are significantly associated with an increased risk of developing gastric carcinoma and even more significantly with non-cardia gastric carcinoma or with intestinal-type gastric carcinoma. Both are significantly associated with an increased risk of developing gastric carcinoma among Caucasians, but not among Asians or Hispanics.

Polymorphic DNA repair and metabolic genes: a multigenic study on gastric cancer

Risk factors for gastric cancer (GC) include inter-individual variability in the inflammatory response to Helicobacter pylori infection, in the ability of detoxifying DNA reactive species and repairing DNA damage generated by oxidative stress and dietary carcinogens. To evaluate the association between polymorphic DNA repair genes and GC risk, a case-control study including 314 histologically confirmed GC patients and 548 healthy controls was conducted in a GC high-risk area in Tuscany, Italy. Polymorphic variants of base excision repair (APE1-D148E, XRCC1-R194W, XRCC1-R399Q and OGG1-S326C), nucleotide excision repair (XPC-PAT, XPA-23G>A, ERCC1-19007T>C and XPD-L751Q), recombination (XRCC3-T241M) and alkylation damage reversal (MGMT-L84F) were tested for their potential role in the development of GC by using logistic regression models. The same population was also characterised for GSTT1 and GSTM1 variant alleles to search for possible functional interactions between metabolic and DNA repair genotypes by two-way interactions using multivariate logistic models. No significant association between any single DNA repair genotype and GC risk was detected with a borderline association with the XPC-PAT homozygous genotype [odds ratio (OR) =1.42; 95% confidence interval (CI) 0.94-2.17]. Gene-gene interaction analysis revealed combinations of unfavourable genotypes involving either multiple DNA repair polymorphisms or DNA repair and GST-specific genotypes. The combination of the XPC-PAT and the XPA variant alleles significantly increased GC risk (OR=2.15; 95% CI 1.17-3.93, P=0.0092). A significant interaction was also found between the APE1 wild-type genotype and either the single GSTT1 (OR=4.90; 95% CI 2.38-10.11, P=0.0079) or double GSTM1-GSTT1 null (OR=7.84; 95% CI 3.19-19.22, P=0.0169) genotypes or the XPA-mutant allele (OR=3.56; 95% CI 1.53-8.25, P=0.0012). These findings indicate that a complex interaction between host factors such as oxidative stress, antioxidant capacity and efficiency of multiple DNA repair pathways underlies the inter-individual variability in GC risk.

Role of interleukin polymorphisms in gastric cancer: "Pros and cons"

Helicobacter pylori (H. pylori) infection is the leading cause of gastric cancer worldwide. Infection with this bacterium causes a chronic active immune response that persists for the life of the host. The combination of bacterial factors, environmental insults, and the host immune response drives the initiation and progression of mucosal atrophy, metaplasia, and dysplasia toward GC. Among the host factors, IL-1 gene cluster polymorphisms (IL-1B encoding IL-1β and IL-1RN encoding IL-1ra, its naturally occurring receptor antagonist) play a decisive role in modulating the risk of developing hypochlorhydria, gastric atrophy and GC in the presence of H. pylori infection. In particular, one single nucleotide polymorphism in the IL-1B promoter (IL-1B-511C⁄T), and the short allele of a 86-bp variable number of tandem repeats polymorphism in the IL-1RN second intron (IL-1RN*2) are associated with an increased risk for GC. However this hypothesis is still to be fully confirmed. This review focuses on the divergent results obtained by several epidemiological and functional in vitro and in vivo studies and show that IL-1 genotyping has still no role in the clinical management of patients with H. pylori infection.

Epidemiology of Helicobacter pylori infection and gastric cancer in Asia

In Asia, the prevalence of Helicobacter pylori (H. pylori) infection varies markedly in different countries. Higher prevalence rates are found in developing Asian countries while lower rates have been reported in more industrialized and developed countries. Within a country, the seroprevalence rates may vary between distinct geographic regions. H. pylori infection is an important etiological factor for the occurrence of non-cardia gastric adenocarcinoma. The incidence rate of gastric adenocarcinoma in Asia tends to mirror the seroprevalence rate of H. pylori infection; however, there are populations with high seroprevalence rates of H. pylori infection that paradoxically have low incidence rates of gastric adenocarcinoma. These diverse clinical outcomes are related to bacterial virulence factors, concomitant environmental factors, host susceptibility and immune response. This review summarizes the current epidemiology of H. pylori infection in Asia and analyzes these data in the context of gastric cancer epidemiology.

Genetic variants in inflammation pathway genes and asthma in glioma susceptibility

Single nucleotide polymorphisms (SNPs) in inflammation-related genes have previously been shown to alter risks of developing various cancers. However, the effects of such SNPs on glioma risk remain unclear. We used a multistrategic approach to elucidate the relationship between glioma risk, asthma/allergies, and 23 literature-based functional SNPs in 11 inflammation genes. Genotyping was conducted on 373 histologically confirmed adult glioma patients and 365 cancer-free controls from the Harris County Brain Tumor Study. Deviations from the Hardy-Weinberg equilibrium were assessed using the chi(2)-test, and Akaike's information criterion was used to determine the best genetic model for each SNP. Odds ratios (ORs) were calculated both for each SNP individually and for grouped analyses, examining the effects of the numbers of adverse alleles on glioma risk in participants with and without asthma. In the single-locus analysis of the 23 examined SNPs, 1 pro-inflammatory and 2 anti-inflammatory gene SNPs were significantly associated with glioma risk (COX2/PTGS2, rs20417 [OR = 1.41]; IL10, rs1800896 [OR = 1.57]; and IL13, rs20541 [OR = 0.39], respectively). When we examined the joint effects of the risk-conferring alleles of these 3 SNPs, we found a significant trend indicating that the risk increases as the number of adverse alleles increase (P = .005). Stratifying by asthma status, we found that this dose-response-like trend of increasing risk is only present among those without asthma/allergies (P < .0001). Our study indicates that polymorphisms in inflammation genes are associated with glioma susceptibility, especially when a history of asthma/allergies is absent.

Helicobacter pylori infection generates genetic instability in gastric cells

The discovery that Helicobacter pylori is associated with gastric cancer has led to numerous studies that investigate the mechanisms by which H. pylori induces carcinogenesis. Gastric cancer shows genetic instability both in nuclear and mitochondrial DNA, besides impairment of important DNA repair pathways. As such, this review highlights the consequences of H. pylori infection on the integrity of DNA in the host cells. By down-regulating major DNA repair pathways, H. pylori infection has the potential to generate mutations. In addition, H. pylori infection can induce direct changes on the DNA of the host, such as oxidative damage, methylation, chromosomal instability, microsatellite instability, and mutations. Interestingly, H. pylori infection generates genetic instability in nuclear and mitochondrial DNA. Based on the reviewed literature we conclude that H. pylori infection promotes gastric carcinogenesis by at least three different mechanisms: (1) a combination of increased endogenous DNA damage and decreased repair activities, (2) induction of mutations in the mitochondrial DNA, and (3) generation of a transient mutator phenotype that induces mutations in the nuclear genome.

Helicobacter pylori infection, host genetics and gastric cancer

Helicobacter pylori infects half the world's population and is responsible for a considerable global health burden, including peptic ulcer disease and gastric cancer. The infection causes a chronic gastritis, the severity and distribution of which determine the clinical outcome. Bacterial, environmental and host genetic factors combine to define the degree of gastric damage. Most patients have a limited mild pan-gastritis with no significant clinical consequences. Antral-predominant gastritis is associated with high gastric acid output and an increased risk of duodenal ulcers. Corpus-predominant gastritis is associated with a reduction in gastric acid, multifocal gastric atrophy and an increased risk of gastric cancer. Host genetic factors are particularly important in defining the severity and extent of Helicobacter-induced gastritis. The most relevant and consistent genetic factors uncovered thus far are in the interleukin-1 and tumor necrosis factor-A gene clusters. These cytokines appear to play a key role in the pathophysiology of gastric cancer and their roles have been confirmed in animal models that mimic human gastric neoplasia. More genetic factors have also been uncovered and, with advancing technology, there is every prospect of defining a full genetic risk profile in the next decade. This will aid in targeting the testing and treatment of Helicobacter pylori, which offers a true opportunity to prevent and defeat this global killer.

Polymorphisms in interleukin 1 beta and interleukin 1 receptor antagonist associated with tumor recurrence in stage II colon cancer

PURPOSE

Identifying molecular markers for tumor recurrence is critical in successfully selecting patients with stage II colon cancer who are more likely to benefit from adjuvant chemotherapy. Interleukin 1 beta (IL1B) and interleukin 1 receptor antagonist (IL1RN) have been shown to play a critical role in the early onset of tumor-associated angiogenesis. In this study, we tested whether eight functionally significant polymorphisms within six genes of the angiogenesis pathway [IL1B, IL1RN, vascular endothelial growth factor A (VEGFA), VEGF receptor 2, interleukin-8, cyclooxygenase-2] will predict the risk of tumor recurrence in stage II colon cancer patients treated with 5-fluorouracil based adjuvant chemotherapy.

EXPERIMENTAL DESIGN

Blood samples were obtained from 109 patients with stage II colon cancer at the University of Southern California medical facilities. DNA was extracted from peripheral blood and the genotypes were analyzed using PCR-restriction fragment length polymorphism protocols.

RESULTS

Patients harboring the IL1RN/IL1B 1-T-C (IL-1RN variable number tandem repeats (VNTR)/IL1B C+3954T/C-511T) haplotype were at greatest risk of developing tumor recurrence [relative risk (RR): 2.72, 95% confidence interval (CI): 1.22-6.08] (adjusted P=0.015). In addition, IL1B +3954 any T (RR: 2.78, 95% CI: 0.99-7.83) (adjusted P=0.043), IL1RN VNTR (RR: 6.09, 95% CI: 1.11-33.4) (adjusted P=0.038), and VEGFA -634 any C (RR: 2.91, 95% CI: 1.13-7.48) (adjusted P=0.026) were shown to be adverse prognostic markers, in both univariate and multivariable analyses.

CONCLUSION

Polymorphisms in IL1B, IL1RN, and VEGFA as well as IL1B/IL1RN haplotype analysis may serve as molecular markers for tumor recurrence in stage II colon cancer, indicating that the analysis of angiogenesis-related gene polymorphisms may help to identify patient subgroups at high risk for tumor recurrence.

The prognostic value of four interleukin-1 gene polymorphisms in Caucasian women with breast cancer: a multicenter study

Background

The proinflammatory cytokine interleukin-1 (IL-1) is known to play an important role in the carcinogenesis of breast cancer. Although IL-1 gene polymorphisms were reported to be associated with increased risk of breast cancer, their influence on survival of Caucasian breast cancer patients remains to be shown.

Methods

We studied the influence of four common gene polymorphisms (IL1A -889C/T, IL1B -511C/T, IL1B +3953E1/E2, and IL1RN long/2) of the IL-1 family on survival in 262 Caucasian patients with breast cancer by univariate and multivariate survival analysis. The combined effect of the four gene polymorphisms on overall survival was studied by haplotype analysis.

Results

In the present study 38 cases of cancer related death and a median time of follow-up (range) of 55.3 (0.4–175.8) months was observed. IL1RN 2/2 (homozygous mutant) gene polymorphism was associated with shortened disease free and overall survival in a univariate (p = 0.001 and p = 0.01, respectively) and multivariate analysis (p = 0.002, Odds Ratio [95% Confidence Interval] = 3.6 [1.6–8.0] and p = 0.05, Odds Ratio = 3.0 [1.1–9.3], respectively). Presence of the homozygous mutant genotype of the IL1A -889 and IL1B +3953 gene polymorphism was associated with overall survival in the univariate (p = 0.004 and p = 0.002, respectively), but not in the multivariate analysis. No association was observed between all possible haplotype combinations and overall survival.

Conclusion

Carriage of the mutant alleles of IL1RN was independently associated with shortened disease free and overall survival rates in Caucasian patients with breast cancer.

CDH1 C-160A promoter polymorphism and gastric cancer risk

The objective of this study was to find out whether C-160A single nucleotide polymorphism of the promoter region of the E-cadherin gene might be a potential genetic marker for identifying individuals at risk for gastric cancer (GC). To test this hypothesis, 412 GC patients and 408 controls were analyzed statistically. A PCR-restriction fragment length polymorphism assay was adopted for C-160A single nucleotide polymorphism detection. No statistical differences were found among CC, CA, and AA genotypes and the risk of GC, even stratifying according to age, sex, and area of residence. Similarly, genotype was not associated with intestinal or diffuse histotypes, or with cardia or noncardia carcinomas. In conclusion, the C-160A polymorphism is not associated with GC risk in the Italian population.

Combined polymorphism analysis of glutathione S-transferase M1/G1 and interleukin-1B (IL-1B)/interleukin 1-receptor antagonist (IL-1RN) and gastric cancer risk in an Omani Arab Population

BACKGROUND

Host genetics have been implicated in gastric cancer carcinogenesis. Polymorphisms of glutathione S-transferase (GST) M1 and G1 and of interleukin-1B (IL-1B) and interleukin-1 receptor antagonist (IL-1RN) were shown to increase gastric cancer predisposition in several studies. To our knowledge, this is the first report on the combined analysis of polymorphisms GSTM1/G1 and IL-1B/IL-1RN genes in gastric adenocarcinoma.

METHODS

Genomic DNA was extracted from peripheral blood of 107 control subjects and 107 gastric cancer patients. Analysis for the GSTM1 and GSTT1 gene polymorphisms was performed by multiplex polymerase chain reaction. The DNA samples were analyzed using the TaqMan allelic discrimination test for the polymorphism of IL-1B at positions-31. The variable number of tandem repeats of IL-1RN was genotyped using polymerase chain reaction followed by agarose gel electrophoresis.

RESULTS

There were no statistically significant associations between the GSTM1/G1 or IL-1B-31 genes and gastric cancer risk. There was a statistical association between the presence of the IL-1RN*2 allele and gastric cancer (odds ratio 2.2, 95% confidence interval=1.2-3.7, P=0.01). Combined analysis showed that a combination of the null GSTM1 genotype and carriers of IL-1RN*2 was associated with a statistically significant correlation with gastric cancer (odds ratio=3.6, 95% confidence interval=1.4-9.4, P=0.008).

CONCLUSIONS

The current study suggests that the individual variation in both the cellular inflammatory modulator IL-1RN and the antioxidative property of GSTM1 may predispose individuals to an increased risk of gastric cancer.

Common variants in interleukin-1-Beta gene are associated with intracranial hemorrhage and susceptibility to brain arteriovenous malformation

BACKGROUND

Polymorphisms in the proinflammatory cytokine interleukin (IL)-1beta gene have been associated with systemic atherogenesis, thrombosis and rupture. The aim of this study was to investigate associations between single nucleotide polymorphisms (SNPs) in IL-1beta and intracranial hemorrhage (ICH) in the natural course of brain arteriovenous malformation (BAVM) patients.

METHOD

Two IL-1beta promoter SNPs (-511C-->T, -31T-->C) and 1 synonymous coding SNP in exon 5 at +3953C-->T (Phe) were genotyped in 410 BAVM patients. We performed a survival analysis of time to subsequent ICH, censoring cases at first treatment, death or last follow-up. A Cox regression analysis was performed to obtain hazard ratios (HRs) for genotypes adjusted for age, sex, Caucasian race/ethnicity and hemorrhagic presentation.

RESULTS

Subjects with the -31 CC genotype (HR = 2.7; 95% CI 1.1-6.6; p = 0.029) or the -511 TT genotype (HR = 2.6; 95% CI 1.1-6.5; p = 0.039) had a greater risk of subsequent ICH compared with reference genotypes, adjusting for covariates. The +3953C-->T SNP was not significantly associated with an increased ICH risk (p = 0.22). The IL-1beta promoter polymorphisms were also associated with BAVM susceptibility among a subset of 235 BAVM cases and 255 healthy controls of Caucasian race/ethnicity (p < 0.001).

CONCLUSION

IL-1beta promoter polymorphisms were associated with an increased risk of ICH in BAVM clinical course and with BAVM susceptibility. These results suggest that inflammatory pathways, including the IL-1beta cytokine, may play an important role in ICH.

Helicobacter pylori: host genetics and disease outcomes

Helicobacter pylori infection is the most common chronic bacterial infection worldwide and is associated with divergent clinical outcomes that range from simple asymptomatic gastritis to more serious conditions, such as peptic ulcer disease and gastric cancer. The key determinants of these outcomes are the severity and distribution of H. pylori-induced gastritis. Host genetic factors play an important role in influencing disease risk, but identifying candidate genes is a major challenge that has to stem from a profound understanding of the pathophysiology of the disease. In the case of H. pylori, the most promising candidate genes are ones that attenuate gastric acid secretion and lead to a destructive chronic inflammatory response against the infection. In particular, certain cytokine and innate immune response gene polymorphisms appear to influence risk of gastric cancer and its precursor conditions. There are currently no convincing genetic risk markers for acquisition of H. pylori infection or risk of developing peptic ulcer disease. Future research agendas should focus on identifying the full genetic risk profile for H. pylori-induced gastric neoplasia. This will help to target the population most at risk by directing eradication therapy and closer follow-up to the affected individuals.

Helicobacter pylori infection and the pathogenesis of gastric cancer: a paradigm for host-bacterial interactions

Helicobacter pylori infection is the most important acquired risk factor for gastric cancer. The infection initiates a chronic inflammatory process that eventually alters the physiology of the gastric environment and leads to achlorohydria. Gastric atrophy may be part of this process but cancer can arise without this precursor. The net effect of decades of inflammation is the establishment of a milieu awash with pro-inflammatory cytokines and characterized by the activation of signalling pathways that cross-talk between inflammation and carcinogenesis. Many of the factors involved in chronic inflammation play a dual role in the process-promoting neoplastic progression but also facilitating cancer prevention. H. pylori bacterial virulence factors as well as host genetic factors play a major role in orchestrating the increased risk of cancer. The study of such host-bacterial interaction is key to uncovering the molecular and cellular pathways involved and will ultimately lead to developing preventive and therapeutic strategies against this global killer.

Helicobacter pylori as a class I carcinogen: physiopathology and management strategies

The gram-negative bacterium Helicobacter pylori is known as a persistent colonizer of the human stomach, and probably less known is that it is also involved in extraintestinal diseases. Public awareness of its contribution in the development of gastric cancer is less than 15 years old. The efficacy of the current therapies based on antibiotics against H. pylori has been limited by difficulties such as antibiotic resistance and recurrence. As a consequence, the development of promising vaccines was prompted as the best preventive measure. Unfortunately, so far vaccines failed the transition from animal models to human trials. This keynote presentation is to provide a bird's eye view of H. pylori-related gastric diseases, including gastric cancer, with a synthesis of the molecular mechanisms involved, and an exhaustive presentation and discussion of the current therapeutic guidelines and future strategies for prevention or therapy.

Genetic aspects of inflammation and cancer

Chronic inflammation is involved in the pathogenesis of most common cancers. The aetiology of the inflammation is varied and includes microbial, chemical and physical agents. The chronically inflamed milieu is awash with pro-inflammatory cytokines and is characterized by the activation of signalling pathways that cross-talk between inflammation and carcinogenesis. Many of the factors involved in chronic inflammation play a dual role in the process, promoting neoplastic progression but also facilitating cancer prevention. A comprehensive understanding of the molecular and cellular inflammatory mechanisms involved is vital for developing preventive and therapeutic strategies against cancer. The purpose of the present review is to evaluate the mechanistic pathways that underlie chronic inflammation and cancer with particular emphasis on the role of host genetic factors that increase the risk of carcinogenesis.

Asia-Pacific consensus guidelines on gastric cancer prevention

BACKGROUND AND AIM

Gastric cancer is a major health burden in the Asia-Pacific region but consensus on prevention strategies has been lacking. We aimed to critically evaluate strategies for preventing gastric cancer.

METHODS

A multidisciplinary group developed consensus statements using a Delphi approach. Relevant data were presented, and the quality of evidence, strength of recommendation, and level of consensus were graded.

RESULTS

Helicobacter pylori infection is a necessary but not sufficient causal factor for non-cardia gastric adenocarcinoma. A high intake of salt is strongly associated with gastric cancer. Fresh fruits and vegetables are protective but the use of vitamins and other dietary supplements does not prevent gastric cancer. Host-bacterial interaction in H. pylori infection results in different patterns of gastritis and differences in gastric acid secretion which determine disease outcome. A positive family history of gastric cancer is an important risk factor. Low serum pepsinogens reflect gastric atrophy and may be useful as a marker to identify populations at high risk for gastric cancer. H. pylori screening and treatment is a recommended gastric cancer risk reduction strategy in high-risk populations. H. pylori screening and treatment is most effective before atrophic gastritis has developed. It does not exclude the existing practice of gastric cancer surveillance in high-risk populations. In populations at low risk for gastric cancer, H. pylori screening is not recommended. First-line treatment of H. pylori infection should be in accordance with national treatment guidelines.

CONCLUSION

A strategy of H. pylori screening and eradication in high-risk populations will probably reduce gastric cancer incidence, and based on current evidence is recommended by consensus.

Is interleukin-1 genotyping useful for the clinical management of patients with atrophic body gastritis?

BACKGROUND

Atrophic body gastritis patients are at increased risk for gastric cancer. IL-1B/IL-1RN polymorphisms have been associated with gastric cancer susceptibility. The relationship between these polymorphisms and the long-term outcome of atrophic body gastritis patients is not known.

AIM

To investigate whether the genotyping of IL-1B-511/IL-1RN polymorphisms is useful to characterize atrophic body gastritis patients at increased risk for gastric neoplasms.

METHODS

IL-1B-511/IL-1RN polymorphisms were compared between 110 atrophic body gastritis patients and 110 age- and gender-matched controls, and patients were followed up (median 4.1 years) according to a cohort study design.

RESULTS

Genotype frequencies of IL-1B-511/IL-1RN were similar between patients and controls. Atrophic body gastritis patients harbouring the wild type of IL-1B-511/IL-1RN polymorphisms were not different from those harbouring the proinflammatory pattern as far as regards gender, age, gastric cancer family history and metaplastic atrophy. Sixteen atrophic body gastritis patients developed a gastric neoplastic lesion at follow-up: eight were IL-1B-511-T carriers and eight were IL-1RN-allele-2 carriers. Harbouring the proinflammatory genotypes was not significantly associated with developing gastric neoplastic lesions.

CONCLUSIONS

In atrophic body gastritis patients, IL-1B-511 and IL-1RN polymorphisms do not appear to be associated either with specific clinical, biochemical or histological features or with the development of gastric neoplastic lesions at long-term follow-up.

Host-bacterial interactions in Helicobacter pylori infection

Helicobacter pylori are spiral-shaped gram-negative bacteria with polar flagella that live near the surface of the human gastric mucosa. They have evolved intricate mechanisms to avoid the bactericidal acid in the gastric lumen and to survive near, to attach to, and to communicate with the human gastric epithelium and host immune system. This interaction sometimes results in severe gastric pathology. H pylori infection is the strongest known risk factor for the development of gastroduodenal ulcers, with infection being present in 60%-80% of gastric and 95% of duodenal ulcers.(1)H pylori is also the first bacterium to be classified as a definite carcinogen by the World Health Organization's International Agency for Research on Cancer because of its epidemiologic relationship to gastric adenocarcinoma and gastric mucosa-associated lymphoid tissue lymphoma.(2) In the last 25 years, since H pylori was first described and cultured, a complete paradigm shift has occurred in our clinical approach to these gastric diseases, and more than 20,000 scientific publications have appeared on the subject. From the medical point of view, H pylori is a formidable pathogen responsible for much morbidity and mortality worldwide. However, H pylori infection occurs in approximately half of the world population, with disease being an exception rather than the rule. Understanding how this organism interacts with its host is essential for formulating an intelligent strategy for dealing with its most important clinical consequences. This review offers an insight into H pylori host-bacterial interactions.

Association between the BRCA2 N372H variant and male breast cancer risk: a population-based case-control study in Tuscany, Central Italy

BACKGROUND

Male breast cancer (MBC) is a rare disease and little is known about its aetiology. Germ-line mutations of BRCA2 and, at lower frequency, of BRCA1 are implicated in a relatively small proportion of MBC cases. Common polymorphic variants in BRCA1 and BRCA2 genes may represent breast cancer (BC) susceptibility alleles and could be associated with a modestly increased risk of MBC at population level. Considering the relevant role of BRCA2 in MBC, we investigated whether the BRCA2 N372H variant, representing the only common non-synonymous polymorphism in BRCA2, might modulate the risk of BC in male populations.

METHODS

A case-control study was performed comparing a population-based series of 99 MBC cases, characterized for BRCA1 and BRCA2 mutations, with 261 male population controls, all residing in Tuscany, Central Italy. All MBC cases and controls were genotyped for the BRCA2 N372H allele by TaqMan allelic discrimination assays. To evaluate the genotype specific risk of the BRCA2 N372H variant, MBC carriers of germ-line BRCA1/2 mutations were excluded from the analyses.

RESULTS

No association emerged in univariate and age-adjusted analyses. Age-specific analyses suggested an increased risk for the HH homozygous genotype in subjects younger than 60 years. A statistically significant interaction emerged between this genotype and age (p = 0.032). When analyses were restricted to MBC cases enrolled in the first 4 years following diagnosis, a recessive model showed a significantly increased risk of MBC in HH subjects younger than 60 years (OR = 5.63; 95% CI = 1.70;18.61).

CONCLUSION

Overall, our findings, although based on a relatively small series, suggest that the BRCA2 HH homozygous genotype might be positively associated with an increased risk of MBC in men younger than 60 years.

Interleukin-1B polymorphisms and gastric cancer risk--a meta-analysis

Some studies have reported that proinflammatory polymorphisms in interleukin-1B (IL-1B) and IL-1 receptor antagonist (IL-1RN) genes are associated with increased gastric cancer risk. However, other studies have shown null or inverse associations. This meta-analysis reviews and summarizes published evidence for these associations. Searching the PubMed Database yielded 35 studies that reported on the association between IL-1B -511 C>T, IL-1B -31 T>C, or IL-1RN variable number tandem repeat polymorphisms and gastric cancer risk. Q-statistics and I(2) statistics were calculated to examine heterogeneity. Summary odds ratios (OR) and 95% confidence intervals (95% CI) were calculated in the random-effects model using the DerSimonian-Laird method. For all gastric cancers, the overall ORs (95% CIs) for IL-1B -511 CT versus CC and TT versus CC genotypes were 1.07 (0.91-1.25) and 1.16 (0.95-1.42), respectively. ORs (95% CIs) for the association between IL-1B -31 CT versus TT and CC versus TT genotypes were 0.99 (0.83-1.19) and 0.98 (0.78-1.21), respectively. For the associations between IL-1RN and gastric cancer, ORs (95% CIs) for *2/L versus LL and *2/*2 versus L/L were 1.15 (0.96-1.38) and 1.23 (0.79-1.92). For each of the examined associations, there was significant heterogeneity among studies; P(heterogeneity) < or = 0.001 and I(2) ranged from 0.54 to 0.71. Noncardia cancers showed stronger associations with IL-1B -511 CT or TT and IL1-RN *2/*2 genotypes, but limiting the analysis to intestinal-type cancers, studies conducted in Western countries, or studies in which polymorphisms were in Hardy-Weinberg equilibrium, made no material difference in the results. The overall associations between IL-1B or IL-1RN proinflammatory polymorphisms and gastric cancer were null but several studies showed an association. The sources of this variation are unclear.

Interleukin-1beta gene (IL-1B) and interleukin 1 receptor antagonist gene (IL-1RN) polymorphisms and gastric cancer risk in an Omani Arab population

BACKGROUND

Gastric cancer (GC) is the most common malignancy in Oman. Interleukin-1beta gene (IL-1B) and interleukin-1 receptor antagonist gene (IL-1RN) polymorphisms have been associated with increased GC risk. No previous studies have examined their role in an Arab population. We tested the associations between polymorphisms of IL1B at positions -31, -511, and +3954 and the IL-1RN polymorphism [variable number of tandem repeats (VNTR) and TC polymorphism at the -2018 position] and GC in Omani Arab patients.

METHODS

Genomic DNA was extracted from peripheral blood of 245 control subjects and 118 gastric cancer patients. The DNA samples were analyzed using the TaqMan allelic discrimination test for IL-1B -31, -511, and +3954 polymorphisms and IL-1RN -2018 polymorphism. The VNTR of IL-1RN was genotyped using the polymerase chain reaction followed by agarose gel electrophoresis.

RESULTS

There was an association between the presence of IL-1RN*2 allele and gastric cancer [odds ratio (OR) = 2.2, 95% confidence interval (CI) = 1.0-3.3, P = 0.04). The GC risk further increased to OR = 3.5 (95% CI = 1.0-11.9) in Helicobacter pylori-positive patients. No association was found between any of the other polymorphisms studied and GC.

CONCLUSION

IL-1RN polymorphism increased the risk of GC in an Omani Arab population, consistent with previous reports. In contrast, the IL-1B -31 polymorphism was not associated with an increased GC risk. These findings underscore the role of cytokine gene polymorphisms in the development of GC and further support the ethnic differences in the effect of IL-1B polymorphism on GC carcinogenesis.

Association of interleukin-1 gene polymorphisms with gastric cancer: a meta-analysis

Previous studies on the association between interleukin-1 (IL-1) genetic polymorphisms and the risk of gastric cancer have produced conflicting results. The purpose of this study was to examine the association between IL-1 genotype and gastric cancer by systematically reviewing the risk of the original studies. Thirty-nine studies, which included 6,863 gastric cancer cases and 8,434 controls, met the inclusion criteria and were included in the meta-analysis. By pooling all the studies identified, the summary odds ratio (OR) of gastric cancer risk associated with IL-1B-511T, -31C, +3954T and IL-1RN*2 was 1.26 (95% confidence interval (CI): 1.03-1.55), 1.00 (95% CI: 0.82-1.22), 1.37 (95% CI: 0.94-2.00) and 1.20 (95% CI: 1.01-1.41), respectively. A stratified analysis showed that IL-1B-511T was associated with an increased risk of gastric cancer (intestinal type) (OR = 1.76, 95% CI: 1.12-2.57). Moreover, IL-1RN*2 was also associated with an increased risk of gastric cancer among Caucasians (OR = 1.30, 95% CI: 1.09-1.54). In conclusion, IL-1B-511 and IL-1RN genetic polymorphisms are associated with an increased risk of developing gastric cancer.

Inflammation, atrophy, and gastric cancer

The association between chronic inflammation and cancer is now well established. This association has recently received renewed interest with the recognition that microbial pathogens can be responsible for the chronic inflammation observed in many cancers, particularly those originating in the gastrointestinal system. A prime example is Helicobacter pylori, which infects 50% of the world's population and is now known to be responsible for inducing chronic gastric inflammation that progresses to atrophy, metaplasia, dysplasia, and gastric cancer. This Review provides an overview of recent progress in elucidating the bacterial properties responsible for colonization of the stomach, persistence in the stomach, and triggering of inflammation, as well as the host factors that have a role in determining whether gastritis progresses to gastric cancer. We also discuss how the increased understanding of the relationship between inflammation and gastric cancer still leaves many questions unanswered regarding recommendations for prevention and treatment.

Interleukin-1beta and interleukin-1 receptor antagonist gene polymorphisms and gastric cancer: a meta-analysis

BACKGROUND

Polymorphisms of interleukin-1B (IL1B) and its receptor antagonist (IL1RN) genes have been inconsistently associated with gastric cancer risk. We examined these associations by performing meta-analyses.

MATERIALS AND METHODS

Twenty-five studies testing the association between IL1B and/or IL1RN gene polymorphisms and gastric cancer were examined: 14 studies of IL1B-511, 14 studies of IL1B-31, 8 studies of IL1B+3954, and 23 studies of IL1RN. Overall and ethnicity-specific summary odds ratios and corresponding 95% confidence intervals for gastric cancer associated with these polymorphisms were estimated using fixed- and random-effects models. Heterogeneity and publication bias were evaluated.

RESULTS

IL1B-511T and IL1RN*2 were associated with gastric cancer risk in Caucasians, but not in Asians. For IL1B-511T, the association in Caucasians was stronger when intestinal-subtype and noncardia gastric cancer cases were examined. A nonsignificant trend was observed between IL1B-31C and gastric cancer in Caucasians. No significant association of IL1B+3954T and gastric cancer risk was detected. Studies with better methodologic characteristics reported stronger effects. There was no evidence of publication bias.

CONCLUSION

IL1B-511T is associated with gastric cancer susceptibility in Caucasians. The meta-analyses suggest that the conflicting results among studies may be explained by variation in allele frequencies among the ethnic groups and variation in tumor types, as well as by the methodologic quality of the studies.

Genetic factors involved in the development of Helicobacter pylori-related gastric cancer

Developmental process to gastric cancer by Helicobacter pylori infection consists of three steps: (1) H. pylori infection; (2) gastric atrophy development; and (3) carcinogenesis. In each step, genetic traits may influence the process, interacting with lifestyle. In the step of H. pylori infection, two lines of genetic polymorphisms were assumed: one influencing gastric acid inhibition interacting with smoking, and the other concerning innate immune response attenuation. The former includes functional polymorphisms of IL-1B (C-31T or tightly linked T-511C), and TNF-A (T-1031C and C-857T), and the latter possibly includes NQO1 C609T. In the step to gastric atrophy, polymorphisms pertaining to the signal transduction from cytotoxin-associated gene A (PTPN11 A/G at intron 3) and to T-cell responses (IL-2 T-330G and IL-13 C-1111T) were hypothesized. There are a limited number of epidemiological genotype studies on the final step of literal carcinogenesis, potentially interacting with smoking, a low vegetable and fruit intake, and salty foods, the well-documented risk factors. In past case-control studies on the associations between genotype and gastric cancer risk, the cases consisted of H. pylori-related and unrelated gastric cancer patients and the controls consisted of individuals including the uninfected (H. pylori unexposed and exposed) and the infected with and without gastric atrophy. Accordingly, it was not clear whether the observed risk was for H. pylori-related or -unrelated gastric cancer, nor which step was involved in the observed associations even when nearly all cases were H. pylori-related. In order to elucidate the genetic traits of H. pylori-related gastric cancer, stepwise evaluation will be required.