Association of interleukin-1beta gene polymorphisms with precancerous gastric lesions in African Americans and Caucasians

Traditional Chinese medicine for precancerous lesions of gastric cancer: A review

Gastric cancer (GC) is the fifth most common type of cancer and the third leading cause of death due to cancer worldwide. The gastric mucosa often undergoes many years of precancerous lesions of gastric cancer (PLGC) stages before progressing to gastric malignancy. Unfortunately, there are no effective Western drugs for patients with PLGC. In recent years, traditional Chinese medicine (TCM) has been proven effective in treating PLGC. Classical TCM formulas and chemical components isolated from some Chinese herbal medicines have been administered to treat PLGC, and the main advantage is their comprehensive intervention with multiple approaches and multiple targets. In this review, we focus on recent studies using TCM treatment for PLGC, including clinical observations and experimental research, with a focus on targets and mechanisms of drugs. This review provides some ideas and a theoretical basis for applying TCM to treat PLGC and prevent GC.

Single nucleotide polymorphisms of whole genes and atrophic gastritis susceptibility:a systematic review and meta-analysis

BACKGROUND

Atrophic gastritis (AG) is one of the important precancerous lesions of gastric cancer. Single nucleotide polymorphisms (SNPs) are closely related to AG susceptibility. However, the research conclusions on the predictive potential of SNPs are inconsistent. The study aims to retrospect the association between SNPs of whole genes and AG risk by meta-analysis.

MATERIALS AND METHODS

Up to April 29, 2020, a systematic literature search for the relationship of SNPs with AG susceptibility was performed utilizing PubMed, Web of Science and Chinese National Knowledge Infrastructure. The overall and stratified meta-analyses on extracted data were conducted by Stata11.2.

RESULTS

33 case-control studies were enrolled containing 9951 AG patients and 17,252 healthy controls, and 17 SNPs in 12 different genes were systematically reviewed. The results indicated that 12 genes could be categorized based on their functions, including immune response, cell proliferation and apoptosis, and DNA damage repair. For the SNPs in immune response-related genes, the C allele of TLR1 rs4833095 T/C increased AG risk to 1.21-fold and the recessive model of TLR4 rs11536878 in the TLR gene family decreased AG susceptibility to 0.48-fold. The variant alleles of IL-10 rs1800871 (OR = 1.21) and IL-8 rs4073 (OR = 1.22) in the IL gene family were positively associated with AG risk. PSCA rs2294008 enhanced AG risk in all genetic models. SNPs associated with AG susceptibility were mainly focused on immune response-related genes.

CONCLUSION

These SNPs related to immune response could influence on AG risk and have potential to be AG predictive biomarkers. It is worth noting that the number of studies for each SNPs were insufficient due to the limited published researches and updated meta-analysis needs to be performed based on extensive relevant studies for more reliable results.

Circulating inflammation-related markers and advanced gastric premalignant lesions

BACKGROUND AND AIM

Chronic Helicobacter pylori infection causes gastric mucosal inflammation as an important antecedent of gastric cancer. We aimed to evaluate associations of blood markers of inflammation with gastric intestinal metaplasia and dysplasia in H. pylori-infected individuals.

METHODS

We compared pre-treatment serum levels of immune-related and inflammation-related markers between 99 individuals with intestinal metaplasia or dysplasia and 75 control individuals with non-atrophic gastritis within an H. pylori eradication trial in Mexico. Serum levels of 28 markers measured with Luminex bead-based assays were categorized in tertiles as low (T1), middle (T2), and high (T3). Logistic regression models were used to calculate age-adjusted and sex-adjusted odds ratios and 95% confidence intervals. All statistical tests were two-sided, and significance values were adjusted for multiple comparisons using false discovery rate methods.

RESULTS

Five markers were nominally associated (P_trend  < 0.05) with the presence of advanced premalignant gastric lesions. Adjusted odds ratios (95% confidence interval) of T2 and T3 versus T1 were 4.09 (1.65-10.17) and 3.08 (1.23-7.68) for CCL3/MIP1A, 3.21 (1.33-7.75) and 2.69 (1.10-6.57) for CCL20/MIP3A levels, 1.79 (0.77-4.18) and 2.39 (1.02-5.60) for IL-1β, 1.34 (0.56-3.19) and 3.02 (1.29-7.12) for IL-4, and 1.07 (0.44-2.59) and 3.07 (1.32-7.14) for IL-5, respectively. Two (IL-4 and IL-5) of the five markers had false discovery rate adjusted P_trend  < 0.2.

CONCLUSIONS

Our results suggest that certain Th2 and other cytokines may have a role in promoting carcinogenesis in the setting of H. pylori infection. Additional research is needed to replicate these findings, extend to pre-diagnostic samples, and elucidate the underlying mechanisms.

Gastric cancer in Latin America

Every year, cancer affects more than one million Latin Americans. The increasing incidence of cancer could be secondary to an aging population, westernization of life style, and urbanization. LA has among the highest incidence rates of gastric cancer, compared to other countries. In this review, different studies on gastric cancer and its relation with risks factors, such as infections, diet and life styles typical of LA, besides the different molecular alterations of that specific population (mainly at a genetic polymorphism level) are analyzed. An exhaustive research was made in PubMed, MEDLINE and Embase of the most relevant studies conducted in the last 27 years (1990-2017) in LA.

Increased expression of deleted in malignant brain tumors (DMBT1) gene in precancerous gastric lesions: Findings from human and animal studies

Helicobacter pylori infection triggers a cascade of inflammatory stages that may lead to the appearance of non-atrophic gastritis, multifocal atrophic, intestinal metaplasia, dysplasia, and cancer. Deleted in malignant brain tumors 1 (DMBT1) belongs to the group of secreted scavenger receptor cysteine-rich proteins and is considered to be involved in host defense by binding to pathogens. Initial studies showed its deletion and loss of expression in a variety of tumors but the role of this gene in tumor development is not completely understood. Here, we examined the role of DMBT1 in gastric precancerous lesions in Caucasian, African American and Hispanic individuals as well as in the development of gastric pathology in a mouse model of H. pylori infection. We found that in 3 different populations, mucosal DMBT1 expression was significantly increased (2.5 fold) in individuals with dysplasia compared to multifocal atrophic gastritis without intestinal metaplasia; the increase was also observed in individuals with advanced gastritis and positive H. pylori infection. In our animal model, H. pylori infection of Dmbt1-/- mice resulted in significantly higher levels of gastritis, more extensive mucous metaplasia and reduced Il33 expression levels in the gastric mucosa compared to H. pylori-infected wild type mice. Our data in the animal model suggest that in response to H. pylori infection DMBT1 may mediate mucosal protection reducing the risk of developing gastric precancerous lesions. However, the increased expression in human gastric precancerous lesions points to a more complex role of DMBT1 in gastric carcinogenesis.

Association between IL-1β polymorphisms and gastritis risk: A meta-analysis

BACKGROUND

Helicobacter pylori (H. pylori) infection of the human stomach regularly leads to chronic gastric inflammation. The cytokine gene interleukin (IL)-1β has been implicated in influencing the pathology of inflammation induced by H. pylori infection. Currently, several studies have been carried out to investigate the association of IL-1β-511 (rs16944) and IL-1β-31 (rs1143627) polymorphisms with gastritis risk; however, the results are inconsistent and inconclusive. To assess the effect of IL-1β polymorphisms on gastritis susceptibility, we conducted a meta-analysis.

METHODS

Up to March 15, 2016, 2205 cases and 2289 controls were collected from 12 published case-control studies. Summarized odds ratios and corresponding 95% confidence intervals (CIs) for IL-1β-511 and IL-1β-31 polymorphisms and gastritis risk were estimated using fixed- or random-effects models when appropriate. Heterogeneity was assessed by chi-squared-based Q-statistic test, and the sources of heterogeneity were explored by subgroup analyses and logistic meta-regression analyses. Publication bias was evaluated by Begg funnel plot and Egger test. Sensitivity analyses were also performed.

RESULTS

The results provided evidences that the single nucleotide polymorphisms (SNPs) in IL-1β-31 might be associated with the gastritis risk, especially in the Caucasian population, while SNPs in the IL-1β-511 might not be.

CONCLUSION

Our studies may be helpful in supplementing the disease monitoring of gastritis in the future, and additional studies to determine the exact molecular mechanisms might inspire interventions to protect the susceptible subgroups.

The homing receptor CD44 is involved in the progression of precancerous gastric lesions in patients infected with Helicobacter pylori and in development of mucous metaplasia in mice

Infection with Helicobacter pylori (H. pylori) leads to inflammatory events that can promote gastric cancer development. Immune cells transition from the circulation into the infected mucosa through the interaction of their receptors and ligands in the endothelial compartment. CD44 expression is increased in advanced gastric lesions. However, the association of this molecule with the progression of these lesions over time has not been investigated. In addition, there is a lack of understanding of the CD44-dependent cellular processes that lead to gastritis, and possibly to gastric cancer. Here we studied H. pylori-positive subjects with gastric lesions that ranged from multifocal atrophic gastritis to dysplasia to determine gene expression changes associated with disease progression over a period of 6 years. We report that CD44 expression is significantly increased in individuals whose gastric lesions progressed along the gastric precancerous cascade. We also show that CD44-/- mice develop less severe and less extensive H. pylori-induced metaplasia, and show fewer infiltrating Gr1+ cells compared to wild type mice. We present data suggesting that CD44 is associated with disease progression. Mechanisms associated with these effects include induction of interferon gamma responses.

Helicobacter pylori-induced inflammation and epigenetic changes during gastric carcinogenesis

The sequence of events associated with the development of gastric cancer has been described as “the gastric precancerous cascade”. This cascade is a dynamic process that includes lesions, such as atrophic gastritis, intestinal metaplasia and dysplasia. According to this model, Helicobacter pylori (H. pylori) infection targets the normal gastric mucosa causing non-atrophic gastritis, an initiating lesion that can be cured by clearing H. pylori with antibiotics or that may then linger in the case of chronic infection and progress to atrophic gastritis. The presence of virulence factors in the infecting H. pylori drives the carcinogenesis process. Independent epidemiological and animal studies have confirmed the sequential progression of these precancerous lesions. Particularly long-term follow-up studies estimated a risk of 0.1% for atrophic gastritis/intestinal metaplasia and 6% in case of dysplasia for the long-term development of gastric cancer. With this in mind, a better understanding of the genetic and epigenetic changes associated with progression of the cascade is critical in determining the risk of gastric cancer associated with H. pylori infection. In this review, we will summarize some of the most relevant mechanisms and focus predominantly but not exclusively on the discussion of gene promoter methylation and miRNAs in this context.

Increased Helicobacter pylori-associated gastric cancer risk in the Andean region of Colombia is mediated by spermine oxidase

Helicobacter pylori infection causes gastric cancer, the third leading cause of cancer death worldwide. More than half of the world's population is infected, making universal eradication impractical. Clinical trials suggest that antibiotic treatment only reduces gastric cancer risk in patients with non-atrophic gastritis (NAG), and is ineffective once preneoplastic lesions of multifocal atrophic gastritis (MAG) and intestinal metaplasia (IM) have occurred. Therefore, additional strategies for risk stratification and chemoprevention of gastric cancer are needed. We have implicated polyamines, generated by the rate-limiting enzyme ornithine decarboxylase (ODC), in gastric carcinogenesis. During H. pylori infection, the enzyme spermine oxidase (SMOX) is induced, which generates hydrogen peroxide from the catabolism of the polyamine spermine. Herein, we assessed the role of SMOX in the increased gastric cancer risk in Colombia associated with the Andean mountain region when compared with the low-risk region on the Pacific coast. When cocultured with gastric epithelial cells, clinical strains of H. pylori from the high-risk region induced more SMOX expression and oxidative DNA damage, and less apoptosis than low-risk strains. These findings were not attributable to differences in the cytotoxin-associated gene A oncoprotein. Gastric tissues from subjects from the high-risk region exhibited greater levels of SMOX and oxidative DNA damage by immunohistochemistry and flow cytometry, and this occurred in NAG, MAG and IM. In Mongolian gerbils, a prototype colonizing strain from the high-risk region induced more SMOX, DNA damage, dysplasia and adenocarcinoma than a colonizing strain from the low-risk region. Treatment of gerbils with either α-difluoromethylornithine, an inhibitor of ODC, or MDL 72527 (N(1),N(4)-Di(buta-2,3-dien-1-yl)butane-1,4-diamine dihydrochloride), an inhibitor of SMOX, reduced gastric dysplasia and carcinoma, as well as apoptosis-resistant cells with DNA damage. These data indicate that aberrant activation of polyamine-driven oxidative stress is a marker of gastric cancer risk and a target for chemoprevention.

At the crossroad between obesity and gastric cancer

Obesity has reached epidemic proportions worldwide with disproportionate prevalence in different communities and ethnic groups. Recently, the American Medical Association recognized obesity as a disease, which is a significant milestone that opens the possibilities of treating obesity under standardized health plans. Obesity is an inflammatory disease characterized by elevated levels of biomarkers associated with abnormal lipid profiles, glucose levels, and blood pressure that lead to the onset of metabolic syndrome. Interestingly, inflammatory biomarkers, in particular, have been implicated in the risk of developing several types of cancer. Likewise, obesity has been linked to esophageal, breast, gallbladder, kidney, pancreatic, and colorectal cancers. Thus, there exists a link between obesity status and tumor appearance, which may be associated to the differential levels and the circulating profiles of several inflammatory molecules. For example, mediators of the inflammatory responses in both obesity and gastric cancer risk are the same: pro-inflammatory molecules produced by the activated cells infiltrating the inflamed tissues. These molecules trigger pathways of activation shared by obesity and cancer. Therefore, understanding how these different pathways are modulated would help reduce the impact that both diseases, and their concomitant existence, have on society.

Interleukin-1β genotype and circulating levels in cancer patients: metastatic status and pain perception

OBJECTIVES

Proinflammatory cytokines released during inflammation can cause hyperexcitability in pain transmission neurons, leading to hyperalgesia and allodynia. Polymorphisms in interleukin 1 (IL-1) family of genes (IL1A, IL1B) and in IL-1 receptor antagonist (IL-1Ra, coded by IL1RN) may therefore induce alterations in cytokine levels/effects and pain related response. Our purpose was to investigate the influence of polymorphisms in IL1A/B/RN on cytokine serum levels and its correlation with pain intensity, performance status, adverse effects, metastases and breakthrough pain in Caucasian cancer patients.

DESIGN AND METHODS

Serum IL-1α/β levels of 74 cancer patients were measured by competitive enzyme immunosorbent assay. All patients were also genotyped for the polymorphisms in IL1A (rs17561), IL1B (rs1143634) and IL1RN (rs419598) with Real-Time PCR. Results were then correlated to the appearance of bone or CNS metastases and several pain-related parameters.

RESULTS

IL-1β rs1143634 homozygous for T allele were associated with lower levels of IL1-β (p=0.032, Mann-Whitney test) and presented a trend for lower levels of pain (p=0.06, Fisher's Exact Test). Also, IL1-β levels were related with cancer onset status, since a four-fold increase probability of metastatic disease was observed in high IL-1β individuals (OR=4.074, p=0.010, Pearson χ(2) test). Among the female patients presenting metastatic disease and carriers of the TT genotype we observed a trend to lower levels of IL1-β (p=0.053, Pearson χ(2) test).

CONCLUSIONS

Our results indicate that genetic variation at IL1-β gene may influence serum levels of IL1-β, with proportional consequences in cancer-related pain.

Interplay between DNA repair and inflammation, and the link to cancer

DNA damage and repair are linked to cancer. DNA damage that is induced endogenously or from exogenous sources has the potential to result in mutations and genomic instability if not properly repaired, eventually leading to cancer. Inflammation is also linked to cancer. Reactive oxygen and nitrogen species (RONs) produced by inflammatory cells at sites of infection can induce DNA damage. RONs can also amplify inflammatory responses, leading to increased DNA damage. Here, we focus on the links between DNA damage, repair, and inflammation, as they relate to cancer. We examine the interplay between chronic inflammation, DNA damage and repair and review recent findings in this rapidly emerging field, including the links between DNA damage and the innate immune system, and the roles of inflammation in altering the microbiome, which subsequently leads to the induction of DNA damage in the colon. Mouse models of defective DNA repair and inflammatory control are extensively reviewed, including treatment of mouse models with pathogens, which leads to DNA damage. The roles of microRNAs in regulating inflammation and DNA repair are discussed. Importantly, DNA repair and inflammation are linked in many important ways, and in some cases balance each other to maintain homeostasis. The failure to repair DNA damage or to control inflammatory responses has the potential to lead to cancer.

C-reactive protein levels in African Americans: a diet and lifestyle randomized community trial

BACKGROUND

Chronic inflammation is linked to poor lifestyle behaviors and a variety of chronic diseases that are prevalent among African Americans, especially in the southeastern U.S.

PURPOSE

The goal of the study was to test the effect of a community-based diet, physical activity, and stress reduction intervention conducted in 2009-2012 on reducing serum C-reactive protein (CRP) in overweight and obese African-American adults.

METHODS

An RCT intervention was designed jointly by members of African-American churches and academic researchers. In late 2012, regression (i.e., mixed) models were fit that included both intention-to-treat and post hoc analyses conducted to identify important predictors of intervention success. Outcomes were assessed at 3 months and 1 year.

RESULTS

At baseline, the 159 individuals who were recruited in 13 churches and had evaluable outcome data were, on average, obese (BMI=33.1 [±7.1]) and had a mean CRP level of 3.7 (±3.9) mg/L. Reductions were observed in waist-to-hip ratio at 3 months (2%, p=0.03) and 1 year (5%, p<0.01). In female participants attending ≥60% of intervention classes, there was a significant decrease in CRP at 3 months of 0.8 mg/L (p=0.05), but no change after 1 year. No differences were noted in BMI or interleukin-6.

CONCLUSIONS

In overweight/obese, but otherwise "healthy," African-American church members with very high baseline CRP levels, this intervention produced significant reductions in CRP at 3 and 12 months, and in waist-to-hip ratio, which is an important anthropometric predictor of overall risk of inflammation and downstream health effects.

TRIAL REGISTRATION

This study is registered at www.clinicaltrials.gov NCT01760902.

MicroRNA: A Bridge from H. pylori Infection to Gastritis and Gastric Cancer Development

Helicobacter pylori (H. pylori) infection is a recognized risk factor for gastric cancer. The disease is one of the most common in the world and explains for a significant number of cancer cases and cancer-associated deaths worldwide. H. pylori infection induces huge array of responses at the gastric epithelial cells and the immune system, inducing both pro- and anti-inflammatory molecules that are intended to either perpetuate or control the infection. Despite the strong immune response, the infection is not cleared and can persist mostly without causing major significant discomfort in the human host. Among the mediators induced in response to the infection, microRNA (miRNA) have the potential to play a major impact on the outcome of the bacteria-host interaction. These miRNA are small 18-24 nucleotide long nucleotide molecules that can interact with mRNA molecules and block their translation into proteins or induce their degradation. Many efforts have been put into the generation of miRNA profiles and their role in gastric cancer. This has led to the identification of miRNA associated with promoting the inflammatory response initiated by the H. pylori infection, increasing the malignant progression of the gastric epithelium, and enhancing the invasiveness and migratory capacity of cancer cells. However, at the same time, several miRNA have been associated with events that are totally opposite, leading to reduced inflammation, inhibition of malignancy and increased apoptosis of transformed cells. In summary, as it is in many other examples, the role played by miRNA in gastric cancer is the results of a delicate balance between pro- and anti-cancer miRNA, and this balance is modified by the interaction of many players, many of which are still waiting to be discovered.

Influence of polymorphisms and TNF and IL1β serum concentration on the infliximab response in Crohn's disease and ulcerative colitis

AIM

Inflammatory bowel diseases (IBD), such as Crohn's disease (CD) and ulcerative colitis (UC), are partially attributable to an increased secretion of proinflamatory cytokines, such as tumour necrosis factor (TNF) and interleukin-1β (IL1β), which play essential roles in the disease pathogenesis and are target molecules for specific therapy. Given the inter-individual variability in the response to the anti-TNF monoclonal antibody infliximab, the aim of our study was to explore the predictive value of TNF and/or IL1β as surrogate markers of infliximab response.

METHODS

Serial serum concentrations of TNF and IL1β and TNF promoter region and IL1B polymorphisms were determined in 47 patients (29 CD and 18 UC) receiving infliximab and correlated with treatment response.

RESULTS

Baseline serum concentrations of TNF and IL1β were higher in UC patients than in CD patients (p = 0.0097 and 0.0024, respectively). CD patients showing <0.64 pg/ml IL1β at baseline were more frequently responders than non-responders (p = 0.036), and the C allele of the IL1B polymorphism was associated with higher IL1β serum concentrations (p = 0.026) and with poorer clinical remission after 14 weeks of infliximab treatment. No significant association was found between serum TNF concentration or TNF polymorphism and patient response to infliximab.

CONCLUSION

This is the first study evaluating the pharmacogenetic role of the rs1143634 polymorphism of IL1B and TNF polymorphisms in infliximab-treated IBD patients. We found an association between the rs1143634 C allele and higher serum IL1β concentrations and a lower response to infliximab treatment in CD patients that warrants the interest of future studies in larger and independent series.

Multifactorial etiology of gastric cancer

The prevalence of gastric cancer is associated with several factors including geographical location, diet, and genetic background of the host. However, it is evident that infection with Helicobacter pylori (H. pylori) is crucial for the development of the disease. Virulence of the bacteria is also important in modulating the risk of the disease. After infection, H. pylori gains access to the gastric mucosa and triggers the production of cytokines that promote recruitment of inflammatory cells, probably involved in tissue damage. Once the infection is established, a cascade of inflammatory steps associated with changes in the gastric epithelia that may lead to cancer is triggered. H. pylori-induced gastritis and H. pylori-associated gastric cancer have been the focus of extensive research aiming to discover the underlying mechanisms of gastric tissue damage. This research has led to the association of host genetic components with the risk of the disease. Among these is the presence of single nucleotide polymorphisms (SNPs) in several genes, including cytokine genes, which are able to differentially modulate the production of inflammatory cytokines and then modulate the risk of gastric cancer. Interestingly, the frequency of some of these SNPs is different among populations and may serve as a predictive factor for gastric cancer risk within that specific population. However, the role played by other genetic modifications should not be minimized. Methylation of gene promoters has been recognized as a major mechanism of gene expression regulation without changing the primary structure of the DNA. Most DNA methylation occurs in cytosine residues in CpG dinucleotide, but it can also be found in other DNA bases. DNA methyltransferases add methyl groups to the CpG dinucleotide, and when this methylation level is too high, the gene expression is turned off. In H. pylori infection as well as in gastric cancer, hypermethylation of promoters of genes involved in cell cycle control, metabolism of essential nutrients, and production of inflammatory mediators, among others, has been described. Interestingly, DNA changes like SNPs or mutations can create CpG sites in sequences where transcription factors normally sit, affecting transcription.In this chapter, we review the literature about the role of SNPs and methylation on H. pylori infection and gastric cancer, with big emphasis to the H. pylori role in the development of the disease due to the strong association between both.

Disease severity in patients infected with Leishmania mexicana relates to IL-1β

Leishmania mexicana can cause both localized (LCL) and diffuse (DCL) cutaneous leishmaniasis, yet little is known about factors regulating disease severity in these patients. We analyzed if the disease was associated with single nucleotide polymorphisms (SNPs) in IL-1β (−511), CXCL8 (−251) and/or the inhibitor IL-1RA (+2018) in 58 Mexican mestizo patients with LCL, 6 with DCL and 123 control cases. Additionally, we analyzed the in vitro production of IL-1β by monocytes, the expression of this cytokine in sera of these patients, as well as the tissue distribution of IL-1β and the number of parasites in lesions of LCL and DCL patients. Our results show a significant difference in the distribution of IL-1β (−511 C/T) genotypes between patients and controls (heterozygous OR), with respect to the reference group CC, which was estimated with a value of 3.23, 95% CI = (1.2, 8.7) and p-value = 0.0167), indicating that IL-1β (−511 C/T) represents a variable influencing the risk to develop the disease in patients infected with Leishmania mexicana. Additionally, an increased in vitro production of IL-1β by monocytes and an increased serum expression of the cytokine correlated with the severity of the disease, since it was significantly higher in DCL patients heavily infected with Leishmania mexicana. The distribution of IL-1β in lesions also varied according to the number of parasites harbored in the tissues: in heavily infected LCL patients and in all DCL patients, the cytokine was scattered diffusely throughout the lesion. In contrast, in LCL patients with lower numbers of parasites in the lesions, IL-1β was confined to the cells. These data suggest that IL-1β possibly is a key player determining the severity of the disease in DCL patients. The analysis of polymorphisms in CXCL8 and IL-1RA showed no differences between patients with different disease severities or between patients and controls.

Leishmania mexicana is an intracellular parasite that causes two polarly opposed diseases: One is a self-limited disease, characterized by ulcerative lesions associated with a low infectious load, as found in patients with localized cutaneous leishmaniasis (LCL). And the other pole is characterized by a progressive disease where abundant parasites spread uncontrollably throughout the skin inside heavily infected phagocytic cells, as occurs in patients with diffuse cutaneous leishmaniasis (DCL). The cause of this severe form of the disease is unknown, although the early encounter between the parasite and the inflammatory response of the host possibly plays a decisive role in the disease outcome. We here show that polymorphism in the gene encoding IL-1β (−511 C/T) represents a variable influencing the risk to develop the disease for patients infected with Leishmania mexicana. In vitro experiments showed that monocytes of DCL patients secreted significantly higher levels of the proinflammatory cytokine IL-1β as compared to LCL patients. DCL patients also had augmented levels of IL-1β in serum, and the cytokine was diffusely distributed throughout lesions, which was correlated with the numbers of parasites in the lesions. We propose that IL-1β possibly plays a key role in establishing the disease severity in patients infected with Leishmania mexicana.

Multifactorial etiology of gastric cancer

The prevalence of gastric cancer is associated with several factors including geographical location, diet, and genetic background of the host. However, it is evident that infection with Helicobacter pylori (H. pylori) is crucial for the development of the disease. Virulence of the bacteria is also important in modulating the risk of the disease. After infection, H. pylori gains access to the gastric mucosa and triggers the production of cytokines that promote recruitment of inflammatory cells, probably involved in tissue damage. Once the infection is established, a cascade of inflammatory steps associated with changes in the gastric epithelia that may lead to cancer is triggered. H. pylori-induced gastritis and H. pylori-associated gastric cancer have been the focus of extensive research aiming to discover the underlying mechanisms of gastric tissue damage. This research has led to the association of host genetic components with the risk of the disease. Among these is the presence of single nucleotide polymorphisms (SNPs) in several genes, including cytokine genes, which are able to differentially modulate the production of inflammatory cytokines and then modulate the risk of gastric cancer. Interestingly, the frequency of some of these SNPs is different among populations and may serve as a predictive factor for gastric cancer risk within that specific population. However, the role played by other genetic modifications should not be minimized. Methylation of gene promoters has been recognized as a major mechanism of gene expression regulation without changing the primary structure of the DNA. Most DNA methylation occurs in cytosine residues in CpG dinucleotide, but it can also be found in other DNA bases. DNA methyltransferases add methyl groups to the CpG dinucleotide, and when this methylation level is too high, the gene expression is turned off. In H. pylori infection as well as in gastric cancer, hypermethylation of promoters of genes involved in cell cycle control, metabolism of essential nutrients, and production of inflammatory mediators, among others, has been described. Interestingly, DNA changes like SNPs or mutations can create CpG sites in sequences where transcription factors normally sit, affecting transcription.In this chapter, we review the literature about the role of SNPs and methylation on H. pylori infection and gastric cancer, with big emphasis to the H. pylori role in the development of the disease due to the strong association between both.

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.

Genetic factors in the pathogenesis of gastroesophageal reflux disease

Multiple factors play a role in the pathogenesis of gastroesophageal reflux disease (GERD). Two landmark studies showing higher concordance of disease in monozygotic than dizygotic twin pairs suggested the role of host genetic factors in its pathogenesis. Recent studies have shown that genetic polymorphism in genes influencing host's inflammatory response, drug metabolism, cell cycle regulation, xenobiotic pathways, DNA repair, mutagenesis, esophageal sensory function and gene silencing are associated with risk of GERD and its sequelae-Barrett's esophagus and esophageal adenocarcinoma. However, more studies on larger sample size are needed before reaching a definite conclusion on the role of an individual gene.

Association of haplotypes of inflammation-related genes with gastric preneoplastic lesions in African Americans and Caucasians

Identification of biomarkers is needed for development of screening programs to prevent gastric cancer. Because racial differences exist in cancer rates, we aimed to evaluate the association between polymorphisms in inflammation-related genes and gastric preneoplastic lesions in African Americans and Caucasians from Louisiana, USA. Gastric biopsies from 569 adults (361 African Americans and 208 Caucasians) undergoing diagnostic endoscopy were used for histological diagnosis and genomic DNA extraction. Polymorphisms within eight genes (IL1B, IL8, IL6, TNF, PTGS2, ARG1, IL10 and TGFB1) were investigated by TaqMan. The cagA status of Helicobacter pylori infection was assessed by PCR. Haplotype logistic regression models were used to identify variables associated with intestinal metaplasia or dysplasia. African Americans carrying the haplotype IL1B-511T/-31C/+3954T, which includes the three risk-associated alleles at the IL1B locus, were more likely to being diagnosed with intestinal metaplasia or dysplasia than those carrying the most common haplotype T-C-C (adjusted OR: 2.51, 95% CI: 1.1-5.5). None of the polymorphisms were associated with intestinal metaplasia and dysplasia in Caucasians. Age and cagA-positive status were independent factors associated with these lesions. Haplotypes at the IL1B locus may participate in mediating the susceptibility to gastric carcinogenesis and might be useful as markers of advanced premalignant lesions in African Americans. Interestingly, carriage of IL1B+3954T allele seems to be the key factor, even though the role played by other polymorphisms cannot be excluded.

Interleukin-1B and interleukin-1 receptor antagonist gene polymorphisms are not associated with premalignant gastric conditions: a combined haplotype analysis

OBJECTIVE

Contradictory results have been reported about the role of interleukin-1B (IL1B) and IL1 receptor antagonist (IL1RN) alleles in gastric carcinogenesis. Here, IL1B and IL1RN polymorphisms were analyzed as genotypes and haplotypes in relation to the presence of atrophic gastritis (AG) and intestinal metaplasia in the stomach.

METHODS

Two hundred and seventy-eight patients (212 Caucasians and 66 Asians) aged 50 years and above, referred for upper endoscopy because of dyspeptic symptoms, were included in the study. Gastric biopsies were histologically assessed according to the updated Sydney classification. Genomic DNA was typed for polymorphisms at position -3737, -1464, -511, -31 for the IL1B gene and the allele 2 of IL1RN using restriction fragment length polymorphism of amplified PCR fragments and intron-spanning PCR analysis, respectively.

RESULTS

IL1B-1464-C/C genotype was associated with higher presence of AG in antrum of the stomach in Caucasians [odds ratio: 4.8 (95% confidence interval=1.7-14.3); P=0.028]. IL1B-1464-G/C genotype was associated with lower incidence of AG in corpus of the stomach in Asians [odds ratio: 0.7 (95% confidence interval=0.5-0.8); P=0.02]. IL1RN*2 allele was not linked with AG or intestinal metaplasia in all parts of the stomach both among Asians and Caucasians. Overall, data show that none of the major four IL1B polymorphisms (IL1B-3737C>T, -1464G>C, -511C>T, -31T>C) and the IL1RN*2 is individually, or in its haplotype configuration, linked to the presence of premalignant lesions in Caucasians.

CONCLUSION

The determination of these IL1-related loci does not have any predictive value for stratification of subgroups with respect to gastric cancer risk.

Association between cytokine gene polymorphisms and gastric precancerous lesions: systematic review and meta-analysis

Polymorphisms within interleukin-1 (IL1) and tumor necrosis factor alpha (TNFA) gene clusters are associated with an increased risk of gastric cancer. However, their role in gastric precancerous lesions remains poorly understood. Our objective was to perform a meta-analysis of studies addressing the association between IL1B-511, IL1RN variable number of tandem repeat, and TNFA-308 gene polymorphisms and gastric precancerous lesions, including original data from Portugal and Mozambique. Published studies on the association between these cytokine gene polymorphisms and gastric precancerous lesions were identified by systematic review, and estimates of the association were combined using random-effects meta-analysis taking into account new data obtained from Portuguese volunteer shipyard workers (n = 215) and Mozambican dyspeptic patients (n = 96) who underwent endoscopic and pathologic evaluation following the same protocol. Odds ratio (OR) estimates for intestinal metaplasia were 2.83 [95% confidence interval (95% CI), 1.15-6.96] for the IL1RN*22 genotype, 1.86 (95% CI, 1.03-3.36) for IL1B-511 T carriers, and 0.59 (95% CI, 0.12-3.04) for the TNFA-308*AA genotype in the Portuguese sample. All Mozambican subjects with intestinal metaplasia were T carriers for IL1B-511 and none had the 2 allele for IL1RN. In meta-analysis, IL1RN*22 genotype was associated with an increased risk of gastric precancerous lesions (22 versus LL: OR, 2.27; 95% CI, 1.40-3.70; I(2) = 26.4%; 12 studies). No such association was found for the IL1B-511 (TT versus CC: OR, 1.34; 95% CI, 0.87-2.07; I(2) = 65.7%; 13 studies) or TNFA-308 genotypes (AA versus GG: OR, 0.93; 95% CI, 0.35-2.43; I(2) = 0.0%; 7 studies). The IL1RN*22 genotype seems to consistently increase the risk of gastric precancerous lesions, supporting a role for this polymorphism in the early stages of gastric carcinogenesis.

Helicobacter pylori and gastric cancer

Helicobacter pylori is now well known as an important pathogen related to the development of gastric cancer. However, some clinicians still doubt the causal association of H. pylori with the development of gastric cancer. To summarize the recent clinical data on the link between H. pylori and gastric cancer, we reviewed related articles published over the past 3 years, after the award of the Nobel Prize for Physiology or Medicine to Drs. J.R. Warren and B.J. Marshall for the first culture and isolation of H. pylori and the investigation of their relevance to peptic ulcer disease. This updated summary of the relationship between H. pylori and gastric cancer highlights the strong link between the organism and the development of gastric cancer, and suggests eradication of this bacterial infection as a possible prophylactic measure against the development of this lethal malignancy. At present, clinicians and researchers in the field emphasize the strong need for H. pylori eradication from the human stomach.

Cytokine genetic polymorphisms and prostate cancer aggressiveness

Prostate cancer (PCa) is one of the most common cancers in the world. Inflammation has been described as a risk factor for PCa and depends on the production of cytokines in response to tissue damage or the presence of stimuli that induces cellular stress. Interindividual variation in cytokine production is partially controlled by single-nucleotide polymorphisms (SNPs) that have been associated with differential production of cytokines. We have recently showed that SNP-SNP interactions of cytokine genes are associated with PCa risk. However, little is known about the association of cytokine SNPs and PCa aggressiveness. In this study, we evaluated the association of 15 SNPs in five cytokine genes and aggressiveness of PCa in African- and Caucasian-American individuals. Caucasian Americans with the genotypes IL10-1082GG or IL1B+3954TT had 2.31-fold [95% confidence interval (CI) = 1.13-4.72] and 3.11 (95% CI = 1.20-8.06)-fold risk, respectively, of developing aggressive PCa, as compared with individuals without those genotypes. We did not find any associations in the African-American group. Using Multivariate Adaptive Regression Splines modeling for exploratory SNP-SNP interactions, our results showed that more aggressive PCa in Caucasians Americans is associated with the CT genotype at IL8-47 [odds ratios (OR) = 3.50; 95% CI = 1.13-10.88] or combined genotypes of IL1B-511CC and IL10-1082GG (OR = 3.38; 95% CI = 1.70-6.71). Unfortunately, the same analysis could not be performed in the African-Americans due to limited number of individuals. With limited sample size, the results from this study suggest that SNPs in cytokine genes may be associated with PCa aggressiveness. More extensive studies are warranted to validate our findings.

Detection of IL-1B-1473 single nucleotide polymorphism in atrophic gastritis using SNaPshot technique

AIM: To evaluate the correlation between IL-1B-1473 gene and atrophic gastritis.

METHODS: Blood samples from 100 patients with atrophic gastritis and 100 patients with non-atrophic gastritis and related epidemiological data were collected. Sample DNA was extracted and IL-1B-1473 single nucleotide polymorphism were genotyped using Multiplex SNaPshot technique.

RESULTS: No significant difference was seen in genotype distribution frequency between the atrophy group and the non-atrophy group. The IL-1B-1473 gene and the atrophic degree of atrophic gastritis were not significantly correlated. Compared with IL-1B-1473C/C, it had a risk increase of 32% for atrophy (OR = 1.32, 95%CI: 0.55-3.16) for IL-1B-1473G/G, but not a significant increase.

CONCLUSION: The IL-1B-1473 gene may have the susceptibility to atrophic gastritis.

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.

Relation of atrophic gastritis with Helicobacter pylori-CagA+ and interleukin-1 gene polymorphisms

AIM: To determine the association of Helicobacter pylori (H pylori) CagA⁺ infection and pro-inflammatory polymorphisms of the genes interleukin (IL)-1RN and IL-1B with the risk of gastric atrophy and peptic ulcers in a dyspeptic population in Costa Rica, a country with high incidence and mortality of gastric cancer.

METHODS: Seven biopsy specimens, a fasting blood sample and a questionnaire concerning nutritional and sociodemographic factors were obtained from 501 consecutive patients who had undergone endoscopy for dyspeptic symptoms. A histopathological diagnosis was made. Pepsinogen concentrations were analyzed by enzyme linked immunosorbent assay (ELISA). Infection with H pylori CagA⁺ was determined by serology and polymerase chain reaction (PCR). IL-1B and IL-1RN polymorphisms genotyping was performed by PCR-restriction fragment length polymorphism (PCR-RFLP) and PCR respectively.

RESULTS: In this dyspeptic population, 86% were H pylori positive and of these, 67.8% were positive for CagA. Atrophic antral gastritis (AAG) was associated with CagA⁺ status [odd ratio (OR) = 4.1; P < 0.000] and fruit consumption (OR = 0.3; P < 0.00). Atrophic body gastritis (ABG) was associated with pepsinogen PGI/PGII < 3.4 (OR = 4.9; P < 0.04) and alcohol consumption (OR = 7.3; P < 0.02). Duodenal ulcer was associated with CagA⁺ (OR = 2.9; P < 0.04) and smoking (OR = 2.4; P < 0.04). PGI < 60 μg/L as well as PGI/PGII < 3.4 were associated with CagA⁺.

CONCLUSION: In a dyspeptic population in Costa Rica, H pylori CagA⁺ is not associated with ABG, but it is a risk factor for AAG. The pro-inflammatory cytokine polymorphisms IL-1B + 3945 and IL-1RN are not associated with the atrophic lesions of this dyspeptic population.

Interleukin-1 receptor antagonist intron 2 variable number of tandem repeats polymorphism and respiratory failure in children with community-acquired pneumonia

OBJECTIVE

To determine whether the variable nucleotide tandem repeat polymorphism in intron 2 of the interleukin-1 receptor antagonist gene is associated with lung injury in children with community-acquired pneumonia.

DESIGN

A prospective cohort of children diagnosed with community-acquired pneumonia.

SETTING

Two pediatric hospitals.

PATIENTS

Eight hundred fifty pediatric patients with community-acquired pneumonia were enrolled.

INTERVENTIONS

Genotyping of the variable nucleotide tandem repeat polymorphism in intron 2 of the interleukin-1 receptor antagonist gene was performed on DNA isolated from whole blood.

MEASUREMENTS AND MAIN RESULTS

The requirement for positive pressure ventilation or the diagnosis of acute lung injury or acute respiratory distress syndrome were the main outcomes of the study. Children (14 days-19 yrs) with community-acquired pneumonia (850) were enrolled; analysis was limited to African American (515) and Caucasian (232) patients. Of the 82 patients requiring positive pressure ventilation, 44 were diagnosed with acute lung injury or acute respiratory distress syndrome. Multivariate logistic regression analyses indicated that children without a copy of the A1 allele of the variable nucleotide tandem repeat polymorphism in intron 2 of the interleukin-1 receptor antagonist gene were more likely to need positive pressure ventilation compared to those with one or two copies of this allele (odds ratio = 2.65, confidence interval, 1.02-6.90). In addition, the absence of the A1 allele also appeared to be associated with the development of community-acquired pneumonia-induced acute lung injury/acute respiratory distress syndrome (odds ratio = 3.1, confidence interval, 0.99-9.67).

CONCLUSIONS

In children with community-acquired pneumonia, absence of the A1 allele at the interleukin-1 receptor antagonist intron 2 polymorphic site is associated with increased risk for more severe lung injury, as measured by the need for positive pressure ventilation or the development of acute lung injury or acute respiratory distress syndrome. Conversely, presence of the A1 allele is associated with decreased risk for more severe lung injury in this patient population.

Genetic association of interleukin-1 haplotypes with gastritis and precancerous lesions in North Indians

BACKGROUND

We evaluated the association of functional variants of IL-1 genes with the development of gastritis and precancerous lesions, which are known to be influenced by inflammatory response against Helicobacter pylori.

METHODS

After upper gastrointestinal (GI) endoscopy, 120 patients with gastritis were tested for H. pylori infection using rapid urease test, modified Giemsa staining and IgG anti-CagA ELISA. All patients and 243 healthy controls were genotyped for IL-1B (-511 C/T) and IL-IRN (VNTR) genes using PCR-RFLP/PCR.

RESULTS

IL-1B: (-511 C/T) genotype/allele were not associated with gastritis. IL-1RN 1/2 genotype carriers had susceptibility to gastritis (p=0.025, OR=1.7). Individuals with the IL-1RN 1/1 genotype (p=0.05, OR=0.65) and IL-1B -511*T-IL-1RN *1 haplotype were at low risk for gastritis (p=0.043, OR=0.72). High secretor haplotype combinations (C1-/T2+, C1-T1+ and T1+/T2+) did not influence neutrophilic infiltration, glandular atrophy or intestinal metaplasia.

CONCLUSIONS

We identified that individuals with the IL-1RN 1/2 genotype had increased risk for gastritis. IL-1B -511*T-IL-1RN *1 (T1) haplotype carriers were at decreased risk for gastritis and no significant association was observed for precancerous lesions in North Indians.

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.

Ethnic differences in cytokine gene polymorphisms: potential implications for cancer development

Differences in incidence and outcome of cancer among ethnic groups may be explained by biological and/or socio-economic factors. Genetic variations that affect chronic inflammation, a potentially important risk factor for carcinogenesis, may differ across ethnic groups. Such differences may help explain cancer disparities among these groups. Single nucleotide polymorphisms (SNPs) within cytokine genes can affect cytokine levels and the degree of inflammation. Associations between cancer and some cytokine SNPs have been suggested. However, these have not been consistently replicated among populations, suggesting that SNP function may differ according to ethnicity, or that SNPs alone do not completely account for regulation of inflammation. We examined seven polymorphisms in African-American (n = 294) and Caucasian (n = 299) newborns in Louisiana: IL1B-511C > T, IL1B-31T > C, IL1B + 3954C > T, IL1RN*2, IL10-1082G > A, IL10-592C > A, and TNF-308G > A. African-American newborns had significantly higher frequencies of IL1B-511T, IL1B-31C, IL10-1082A and IL10-592A alleles and complete linkage equilibrium between IL1B + 3954 and IL1B-31. In contrast, IL1B + 3954T, IL1RN*2, and TNF-308A were more frequent in Caucasian newborns and exhibited strong linkage disequilibrium between IL1B + 3954 and IL1B-31. All allelic frequencies were significantly different between groups. We hypothesize that these dissimilarities may contribute to differences in the inflammatory response and cancer incidence and mortality between African-Americans and Caucasians in Louisiana.

Investigation of functional gene polymorphisms: IL-1B, IL-6 and TNFA in benign migratory glossitis in Brazilian individuals

BACKGROUND

Benign migratory glossitis (BMG) is a very common immunological oral disease of unknown aetiology.

METHODS AND SUBJECTS

Fifty-three consecutive subjects affected by BMG and 53 age- and sex-matched control subjects were genotyped for IL-1B, IL-6 and TNFA polymorphisms. Binary logistic regression models were fitted and values of P < 0.05 were considered significant.

RESULTS

A significant difference in the distribution of IL-1B genotypes was observed in the group with BMG in univariate analyses (P = 0.01). The multivariate analyses showed that the CT genotype of the IL1-B gene was significantly associated with a high risk to develop BMG (P = 0.02, OR 2.76). The combined presence of IL-1beta high and intermediate producers genotypes was also associated with BMG in multivariate analyses (P = 0.01, OR 3.05). IL-6 and TNFA polymorphisms were not associated with BMG in the univariate and multivariate analyses.

CONCLUSION

Our findings demonstrate that the polymorphism +3954 IL-1B is associated with an increased risk of BMG development and suggest a genetic basis for disease development.

Association of IL1B polymorphisms with gastric cancer in a Chinese population

OBJECTIVES

To investigate the association between IL1B polymorphisms and risk of gastric cancer in a Chinese population, seven SNPs in the IL1B gene were selected for this study.

METHODS

A multiplex genotyping method, which is based on adapter ligation and allele-specific amplification, was established to type seven SNPs on the IL1B gene simultaneously. One hundred and forty-one non-cancer outpatients and 97 patients with gastric cancer were genotyped, and the relation between IL1B polymorphisms and gastric cancer was statistically analyzed.

RESULTS

The seven SNPs were successfully typed and the results were consistent with those obtained by both Sanger's sequencing and PCR-RFLP. Handling with statistical analysis, we observed significantly different genotype frequencies of 0794C>T (chi(2)=6.11, P=0.05), 1274C>T (chi(2)=6.86, P=0.03) and 2143T>C (chi(2)=6.86, P=0.03) between patients and controls.

CONCLUSION

ALM-ASA is a potential method for multiplex SNP typing with a low consumption of genomic DNA. SNPs 0794C>T, 1274C>T, and 2143T>C are associated with gastric cancer.

Helicobacter pylori and gastric cancer

PURPOSE OF REVIEW

Although chronic Helicobacter pylori infection is the strongest known risk factor for development of gastric adenocarcinoma, only a small proportion of infected individuals will ever develop tumours. This article discusses various bacterial, host and environmental factors which may influence an individual's susceptibility.

RECENT FINDINGS

Recent research on bacterial virulence factors has focussed upon the cag pathogenicity island, particularly its roles in regulating epithelial growth and adhesion. Studies of host genetic factors have included several analyses of polymorphisms in inflammatory cytokines in human cohorts. Animal studies have recently clarified the roles of dysregulated epithelial apoptosis, proliferation and differentiation pathways during gastric carcinogenesis, and novel experiments involving H. felis infection of bone marrow transplanted irradiated mice have suggested that gastric cancer may originate from bone marrow-derived stem cells. Important roles for signalling between epithelial and mesenchymal cells, particularly myofibroblasts, are also emerging. Recent research on the importance of environmental factors has demonstrated how helminth coinfection may protect against atrophic gastritis and T helper type 1 responses.

SUMMARY

Complex interactions between several bacterial, host genetic and environmental factors determine whether H. pylori infected individuals develop gastric carcinoma. The importance of bone marrow stem cell engraftment during human gastric neoplasia is an area requiring urgent investigation.