Influence of Helicobacter pylori infection on the expression of MLH1 and MGMT in patients with chronic gastritis and gastric cancer

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effect of Helicobacter pylori infection on IL-8, IL-1 and COX-2 expression in patients with chronic gastritis and gastric cancer

Objective. Helicobacter pylori infection is related to gastric cancer development, and chronic inflammation is presumed to be the main cause. The aim of the present study was to evaluate the influence of H. pylori cagA, vacA, iceA, and babA genotypes on COX-2, IL-1, and IL-8 expression. Material and methods. of the 217 patients included in the study, 26 were uninfected, 127 had chronic gastritis and were H. pylori-positive, and 64 had gastric cancer. Bacterial genotypes were evaluated by polymerase chain reaction (PCR), and the expression values were determined by quantitative real-time PCR and immunohistochemistry. Results. An association was found between the infection with cagA, vacA s1m1 strains and gastric cancer development. Regarding the 3' region of the cagA gene, we also found an association between the infection with cagA EPIYA-ABCCC strains and clinical outcome. Higher levels of IL-8, IL-1, and COX-2 were detected in gastric mucosa from infected patients with chronic gastritis, and they were also associated with the infection by cagA, vacA s1m1 strains. The IL-8 and IL-1 levels decrease significantly from chronic gastritis to gastric cancer, while the relative expression remained unaltered when COX-2 expression was analyzed among patients with gastritis and cancer. Conclusions. Since inflammatory response to H. pylori infection plays an important role in cellular proliferation and gastric mucosal damage, the up-regulation of IL-1, IL-8, and COX-2 in patients with chronic gastritis has an important clinical implication in gastric carcinogenesis.

Effects of Helicobacter pylori Infection on the Expressions of Bax and Bcl-2 in Patients with Chronic Gastritis and Gastric Cancer

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

IL-1ra anti-inflammatory cytokine polymorphism is associated with risk of gastric cancer and chronic gastritis in a Brazilian population, but the TNF-beta pro-inflammatory cytokine is not

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Methylation status of CDH1 gene in samples of gastric mucous from brazilian patients with chronic gastritis infected by Helicobacter pylori

CONTEXTO:O câncer gástrico é uma das principais neoplasias que causam o óbito no Brasil e no mundo. Helicobacter pylori é um carcinógeno do tipo I relacionado à gastrite crônica. Diferenças no grau de virulência de suas cepas levam a maior risco de desenvolvimento de doenças gástricas. A metilação de ilhas CpGs está envolvida com o processo de tumorigênese em diferentes tipos de câncer. CDH1 é um gene supressor tumoral que, quando inativado, pode aumentar as chances de metástase. A metilação deste gene em estágios precoces da carcinogênese gástrica ainda não é totalmente compreendida. OBJETIVO: Investigar o padrão de metilação do gene CDH1 em amostras de gastrites crônicas e correlacionar com a presença do H. pylori. MÉTODOS: Foram usadas 60 biopsias de mucosas gástricas. A detecção de H. pylori foi realizada por PCR para o gene da urease C e a genotipagem com PCR para os genes cagA e vacA (região s e m). O padrão de metilação do gene CDH1 foi analisado usando a técnica de PCR e específica para a metilação e sequenciamento direto dos produtos de PCR. RESULTADOS: A bactéria H. pylori foi detectada em 90% das amostras de gastrites crônicas; destas, 33% portavam o gene cagA e 100% vacA s1. O genótipo vacA s2/m1 não foi detectado nas amostras analisadas. Metilação de CDH1 foi detectada em 63,3% das amostras de gastrites e 95% delas eram portadoras de H. pylori. CONCLUSÃO: Os resultados deste estudo sugerem que a metilação em CDH1 e a infecção pelo H. pylori são eventos frequentes em amostras de pacientes brasileiros com gastrite crônica e reforça a correlação entre infecção por H. pylori e inativação do gene CDH1 em estágios precoces da tumorigênese gástrica.

Polymorphisms of DNA repair genes XRCC1 and XRCC3, interaction with environmental exposure and risk of chronic gastritis and gastric cancer

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

GSTT1, GSTM1 and CYP2E1 genetic polymorphisms in gastric cancer and chronic gastritis in a Brazilian population

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Polymorphisms of DNA repair genes XRCC1 and XRCC3, interaction with environmental exposure and risk of chronic gastritis and grastic cancer

Aim: To evaluate the association between polymorphisms XRCC1 Arg194Trp and Arg399Gln and XRCC3 Thr241Met and the risk for chronic gastritis and gastric cancer, in a Southeastern Brazilian population. Methods: Genotyping by PCR-RFLP was carried out on 202 patients with chronic gastritis (CG) and 160 patients with gastric cancer (GC), matched to 202 (C1) and 150 (C2) controls, respectively. Results: No differences were observed among the studied groups with regard to the genotype distribution of XRCC1 codons 194 and 399 and of XRCC3 codon 241. However, the combined analyses of the three variant alleles (194Trp, 399Gln and 241Met) showed an increased risk for chronic gastritis when compared to the GC group. Moreover, an interaction between the polymorphic alleles and demographic and environmental factors was observed in the CG and GC groups. XRCC1 194Trp was associated with smoking in the CG group, while the variant alleles XRCC1 399Gln and XRCC3 241Met were related with gender, smoking, drinking and H pylori infection in the CG and GC groups. Conclusion: Our results showed no evidence of a rela-tionship between the polymorphisms XRCC1 Arg194Trp and Arg399Gln and XRCC3 Thr241Met and the risk of chronic gastritis and gastric cancer in the Brazilian population, but the combined effect of these variants may interact to increase the risk for chronic gastritis, considered a premalignant lesion. Our data also indicate a gene-environment interaction in the susceptibility to chronic gastritis and gastric cancer. © 2005 The WJG Press and Elsevier Inc. All rights reserved.

Genetic alterations in benign lesions: Chronic gastritis and gastric ulcer

Aim: To investigate the occurrence of chromosome 3, 7, 8, 9, and 17 aneuploidies, TP53 gene deletion and p53 protein expression in chronic gastritis, atrophic gastritis and gastric ulcer, and their association with H pylori infection. Methods: Gastric biopsies from normal mucosa (NM, n = 10), chronic gastritis (CG, n = 38), atrophic gastritis (CAG, n = 13) and gastric ulcer (GU, n = 21) were studied using fluorescence in situ hybridization (FISH) and immunohistochemical assay. A modified Giemsa staining technique and PCR were used to detect H pylori. An association of the gastric pathologies and aneuploidies with H pylori infection was assessed. Results: Aneuploidies were increasingly found from CG (21%) to CAG (31%) and to GU (62%), involving mainly monosomy and trisomy 7, trisomies 7 and 8, and trisomies 7, 8 and 17, respectively. A significant association was found between H pylori infection and aneuploidies in CAG (P = 0.0143) and GU (P = 0.0498). No TP53 deletion was found in these gastric lesions, but p53-positive immunoreactivity was detected in 45% (5/11) and 12% (2/17) of CG and GU cases, respectively. However, there was no significant association between p53 expression and H pylori infection. Conclusion: The occurrence of aneuploidies in benign lesions evidences chromosomal instability in early stages of gastric carcinogenesis associated with H pylori infection, which may confer proliferative advantage. The increase of p53 protein expression in CG and GU may be due to overproduction of the wild-type protein related to an inflammatory response in mucosa. © 2006 The WJG Press. All rights reserved.

Expression of annexin-A1 and galectin-1 anti-inflammatory proteins and mRNA in chronic gastritis and gastric cancer

Objective. The anti-inflammatory proteins annexin-A1 and galectin-1 have been associated with tumor progression. This scenario prompted us to investigate the relationship between the gene and protein expression of annexin-A1 (ANXA1/AnxA1) and galectin-1 (LGALS1/Gal-1) in an inflammatory gastric lesion as chronic gastritis (CG) and gastric adenocarcinoma (GA) and its association with H. pylori infection. Methods. We analyzed 40 samples of CG, 20 of GA, and 10 of normal mucosa (C) by the quantitative real-time PCR (qPCR) technique and the immunohistochemistry assay. Results. High ANXA1 mRNA expression levels were observed in 90% (36/40) of CG cases (mean relative quantification RQ = 4.26 ± 2.03) and in 80% (16/20) of GA cases (mean RQ = 4.38 ± 4.77). However, LGALS1 mRNA levels were high (mean RQ = 2.44 ± 3.26) in 60% (12/20) of the GA cases, while low expression was found in CG (mean RQ = 0.43 ± 3.13; P < 0.01). Normal mucosa showed modest immunoreactivity in stroma but not in epithelium, while stroma and epithelium displayed an intense immunostaining in CG and GA for both proteins. Conclusion. These results have provided evidence that galectin-1 and mainly annexin-A1 are overexpressed in both gastritis and gastric cancer, suggesting a strong association of these proteins with chronic gastric inflammation and carcinogenesis. © 2013 Yvana Cristina Jorge et al.

Interleukin-6 polymorphism and Helicobacter pylori infection in Brazilian adult patients with chronic gastritis

Helicobacter pylori is recognised as the most common cause of chronic active gastritis and this bacterium is also an important pathogenic factor in peptic ulcer disease. The biological factors that influence clinical outcome in H. pylori infection have been extensively studied. In addition to immunological factors in the host, bacterial virulence determinants in H. pylori strains are likely to play a crucial role in gastric cancer development. Single-nucleotide polymorphisms at the 5' flanking region of the interleukin (IL)-6 gene promoter (G or C at -174 base) have been identified and individuals with the G allele at position -174 have been shown to produce higher levels of IL-6 than those with the C/C genotype. The mucosal levels of IL-6 were reported to be increased in H. pylori-associated gastritis. The present study was conducted to examine any relationship between inflammatory cytokine polymorphisms and the inflammatory process in mucosa infected by H. pylori. In our study we did not find any association between the C and G alleles in adult patients with chronic gastritis and inflammatory process in gastric mucosa.

Irregular meal timing is associated with helicobacter pylori infection and gastritis

Background Helicobacter pylori (HP) is associated with chronic gastritis and gastric cancer, and more than half of the world’s population is chronically infected. The aim of this retrospective study was to investigate whether an irregular meal pattern is associated with increased risk of gastritis and HP infection. Methods The study involved 323 subjects, divided into three groups: subjects with HP infection and gastritis, with gastritis, and a control group. Subjects were interviewed on eating habits and meal timing. Multivariate logistic regression was used to compare groups. Adjusted odds ratios (OR) were derived controlling for gender, age, stress and probiotic consumption. Results Subjects who deviated from their regular meals by 2 hours or more had a significantly higher incidence of HP infection with gastritis (adjusted OR= 13.3, 95% CI 5.3–33.3, p<0.001) and gastritis (adjusted OR=6.1, 95% CI 2.5–15.0, p<0.001). Subjects who deviated their meals by 2 hours or more, twice or more per week, had an adjusted OR of 6.3 and 3.5 of acquiring HP infection with gastritis (95% CI 2.6–15.2, p<0.001) and gastritis (95% CI 1.5–8.5, p<0.001) respectively. Conclusion Frequent deviation in meal timing over a prolonged period appears associated with increased risk of developing HP infection and gastritis.

The role of probiotics in Helicobacter pylori infection

Helicobacter pylori (H. pylori) infection is a major cause of chronic gastritis and peptic ulcer disease, and it is also designated as a class-I carcinogen for stomach cancer. The role of probiotics in the treatment of gastrointestinal infections is increasingly documented as an alternative or complement to antibiotics, with the potential to decrease the use of antibiotics or reduce their adverse effects. These studies were conducted to investigate the role of probiotics in the treatment of H. pylori infection. Various aspects included: an investigation of the effects of a probiotic combination consisting of Lactobacillus rhamnosus GG, L. rhamnosus LC705, Propionibacterium freudenreichii ssp. shermanii JS and Bifidobacterium breve Bb99 or B. lactis Bb12 as a supplementation to H. pylori eradication therapy, with special reference to tolerability, effectiveness, and microbiota alterations following the treatment; discovering the role of probiotics in vivo with H. pylori infected and uninfected patients, as well as with an in vitro model of H. pylori infection. The probiotic combination therapy was able to reduce significantly the total symptom score, which takes into account both the frequency and the severity of the adverse effects, during the eradication treatment. The supplementation did not improve the success of the eradication treatment significantly, though some difference was seen in the eradication percentages (91% vs. 79%). The quantities of predominant bacterial groups were altered significantly following the triple treatment. Probiotics slightly counteracted the effects of anti-H. pylori treatment, monitored as significantly less alterations in the total numbers of aerobes and lactobacilli/enterococci group bacteria. After probiotic intervention, L. rhamnosus GG adhered to a minority of the patients upper gastrointestinal mucosa, but all of the probiotics survived well through the gastrointestinal tract transit with and without antimicrobial treatment. Probiotic intervention decreased gastrin-17 levels in H. pylori infected patients and appeared to decrease the 13C-urea breath test values. In in vitro Caco-2 cell line experiments, probiotics inhibited H. pylori adhesion to intestinal epithelial cells. Both L. rhamnosus strains, P. freudenreichii ssp. shermanii JS and the combination inhibited the H. pylori-induced acute cell leakage. Simultaneously, both L.rhamnosus strains and the combination transiently improved the epithelial barrier function. The pro-inflammatory effects prevailed when the probiotics were used in combination. According to this series of studies, probiotic combination could have some potential in reducing adverse effects induced by H. pylori eradication treatment and beneficial effects on H. pylori infected subjects.

Expression, purification and X-ray crystallographic analysis of the Helicobacter pylori blood group antigen-binding adhesin BabA

Helicobacter pylori is a human pathogen that colonizes about 50% of the world's population, causing chronic gastritis, duodenal ulcers and even gastric cancer. A steady emergence of multiple antibiotic resistant strains poses an important public health threat and there is an urgent requirement for alternative therapeutics. The blood group antigen-binding adhesin BabA mediates the intimate attachment to the host mucosa and forms a major candidate for novel vaccine and drug development. Here, the recombinant expression and crystallization of a soluble BabA truncation (BabA^25-460) corresponding to the predicted extracellular adhesin domain of the protein are reported. X-ray diffraction data for nanobody-stabilized BabA^25-460 were collected to 2.25Å resolution from a crystal that belonged to space group P21, with unit-cell parameters a = 50.96, b = 131.41, c = 123.40Å, α = 90.0, β = 94.8, γ = 90.0°, and which was predicted to contain two BabA^25-460-nanobody complexes per asymmetric unit.

Prevalence of helicobacter pylori infection in advanced gastric carcinoma

There is substantial evidence that infection with Helicobacter pylori plays a role in the development of gastric cancer and that it is rarely found in gastric biopsy of atrophic gastritis and gastric cancer. On advanced gastric tumors, the bacteria can be lost from the stomach. Aims - To analyze the hypothesis that the prevalence of H.pylori in operated advanced gastric carcinomas and adjacent non-tumor tissues is high, comparing intestinal and diffuse tumors according to Lauren’s classifi cation. Methods - A prospective controlled study enrolled 56 patients from “Hospital Universitário”, Federal University of Rio Grande do Norte, Natal, RN, Brazil, with advanced gastric cancer, treated from February 2000 to March 2003. Immediately after partial gastrectomy, the resected stomach was opened and several mucosal biopsy samples were taken from the gastric tumor and from the adjacent mucosa within 4 cm distance from the tumor margin. Tissue sections were stained with hematoxylin and eosin. Lauren‘s classifi cation for gastric cancer was used, to analyse the prevalence of H. pylori in intestinal or diffuse carcinomas assessed by the urease rapid test, IgG by ELISA and Giemsa staining. H. pylori infected patients were treated with omeprazole, clarithromycin and amoxicillin for 7 days. Follow-up endoscopy and serology were performed 6 months after treatment to determine successful eradication of H. pylori in non-tumor tissue. Thereafter, follow-up endoscopies were scheduled annually. Chi-square and MacNemar tests with 0.05 signifi cance were used. Results - Thirty-four tumors (60.7%) were intestinal-type and 22 (39.3%) diffuse type carcinomas. In adjacent non-tumor gastric mucosa, chronic gastritis were found in 53 cases (94.6%) and atrophic mucosa in 36 patients (64.3%). All the patients with atrophic mucosa were H. pylori positive. When examined by Giemsa and urease test, H. pylori positive rate in tumor tissue of intestinal type carcinomas was higher than that in diffuse carcinomas. In tumor tissues, 34 (60.7%) H. pylori-positive in gastric carcinomas were detected by Giemsa method. H. pylori was observed in 30 of 56 cases (53.5%) in tissues 4 cm adjacent to tumors. This difference was not signifi cant. Eradication of H. pylori in non-tumor tissue of gastric remnant led to a complete negativity on the 12th postoperative month. Conclusions - The data confi rmed the hypothesis of a high prevalence of H. pylori in tumor tissue of gastric advanced carcinomas and in adjacent non-tumor mucosa of operated stomachs. The presence of H. pylori was predominant in the intestinal-type carcinoma