The diversity of vacA and cagA genes was investigated by PCR and sequence analysis in 30 isolates obtained from Japanese paediatric patients with peptic ulcer (eight strains) or chronic gastritis (22 strains).
The genotyping of H. pylori strains directly from gastric biopsy using the same nucleic acid methodology revealed that there is no association of chronic gastritis in our infant patients with vacA s1 and the presence of the cagA gene.
The cagA gene and non-opsonic neutrophil activation capacity were co-expressed in 14 of 24 (58.3%) strains from patients with peptic ulcer disease, and in nine of 29 (31%) strains from individuals with chronic gastritis.
Determining the relationship between the genotypes and clinical features, we found that the cagA gene was more closely associated with duodenal ulcer than with gastric ulcer and the vacA s1a/m2 strain was more closely associated with active chronic gastritis and atrophic gastritis than with chronic gastritis.
IL-8-845 C allele carriers were significantly upregulated in both groups (GC and CG; RQ = 3.138 and 2.181, respectively) when compared to TT homozygotes (RQ = -0.407 and 0.165, respectively).
We found that dupA status was not associated with any gastroduodenal disease, histological score of chronic gastritis or with the extent of interleukin-8 production from gastric cell lines.
We found no significant association between the IL8-251 polymorphism and increased risk of chronic gastritis or gastric carcinoma, in agreement with that reported in other populations of white origin.
A total of 153 H. pylori isolates from patients with chronic gastritis (n = 74) or gastro-duodenal ulcers (n = 79) was examined for vacA genotypes and cagA status by polymerase chain reaction (PCR) and dot blot, and for their ability to induce IL-8 secretion by HEp-2 cells.
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.
Our results indicate that the IL-1β -511 C/C and C/T gene polymorphisms are associated with chronic gastritis and GC development in H. pylori-infected individuals.
The GSTT1 null genotype occurred more frequently in Negroid subjects, and the GSTM1 null genotype in Caucasians, while the GSTM1 positive genotype was observed mainly in individuals with chronic gastritis infected with H pylori.
The GSTT1 null genotype occurred more frequently in Negroid subjects, and the GSTM1 null genotype in Caucasians, while the GSTM1 positive genotype was observed mainly in individuals with chronic gastritis infected with H pylori.
Five different classes of methylation behaviors were found: (a). genes methylated in GC only (GSTP1 and RASSF1A), (b). genes showing low methylation frequency (<12%) in CG, IM, and gastric adenoma (GA) but significantly higher methylation frequency in GC (COX-2, hMLH1, p16), (c). a gene with low and similar methylation frequency (8.8-21.3%) in four-step lesions (MGMT), (d). genes with high and similar methylation frequency (53-85%) in four-step lesions (APC and E-cadherin), and (e). genes showing an increasing tendency with or without fluctuation of the methylation frequency along the progression (DAP-kinase, p14, THBS1, and TIMP-3).
In conclusion, our study shows that Colombian patients with chronic gastritis have a significantly higher prevalence of small MUC1 alleles than the Portuguese population.
Five different classes of methylation behaviors were found: (1) genes methylated in GC only (GSTP1 and RASSF1A); (2) genes showing low methylation frequency (<12%) in CG, IM, and GA, but significantly higher methylation frequency in GC (COX-2, hMLH1, and p16); (3) a gene with low and similar methylation frequency (8.8-21.3%) in four-step lesions (MGMT); (4) genes with high and similar methylation frequency (53-85%) in four-step lesions (APC and E-cadherin); and (5) genes showing an increasing tendency with or without fluctuation of the methylation frequency along the progression (DAP-kinase, p14, THBS1, and TIMP3).
Our data suggest that the GSTP1 genotype seems not to be associated with the risk of gastric cancer and chronic gastritis in a high-risk Chinese population.
The population of patients with CG shows MUC1 allele frequencies significantly different from the gastric carcinoma patients and blood donors population.
There was a significant difference in TNF-α concentrations between patients with mild chronic gastritis and TNF-α -308 GG genotype and patients with moderate to severe chronic gastritis (P = 0.008).