Relationships between cagA, vacA, and iceA genotypes of Helicobacter pylori and DNA damage in the gastric mucosa.
Helicobacter pylori (H. pylori) is believed to predispose carriers to gastric cancer by inducing chronic inflammation. The inflammatory processes may result in the generation of reactive oxygen and nitrogen species that damage DNA. In this study, we investigated the relationships between DNA damage in the gastric mucosa and cagA, vacA, and iceA genotypes of H. pylori. The study was conducted with biopsies from the gastric antrum and corpus of 98 H. pylori-infected and 26 uninfected control patients. H. pylori genotypes were determined by PCR and DNA damage was measured in gastric mucosal cells by the Comet assay (single cell gel electrophoresis). All patients were nonsmokers, not abusing alcohol, and not using prescription or recreational drugs. Levels of DNA damage were significantly higher (P < 0.0001) in the H. pylori-infected patients than in uninfected patients. In comparison with the level of DNA damage in the uninfected controls, the extent of DNA damage in both the antrum (OR = 8.45; 95% CI = 2.33-37.72) and the corpus (OR = 6.55; 95% CI = 2.52-17.72) was related to infection by cagA+/vacAs1m1 and iceA1 strains. The results indicate that the genotype of H. pylori is related to the amount of DNA damage in the gastric mucosa. These genotypes could serve as biomarkers for the risk of extensive DNA damage and possibly gastric cancer.
Departamento de Genética, Instituto de Biociências, Universidade Estadual Paulista, Botucatu, São Paulo, Brazil.
Marcelo S P
MS
Ladeira
Maria A M
MA
Rodrigues
Daisy M F
DM
Salvadori
Pedro Padulla
PP
Neto
Pedro
P
Achilles
Mauro M
MM
Lerco
Paulo A
PA
Rodrigues
Irio
I
Gonçalves
Dulciene M M
DM
Queiroz
Dértia V
DV
Freire-Maia
D000328:Adult; D000368:Aged; D000942:Antigens, Bacterial / Q000235:genetics*; D001426:Bacterial Proteins / Q000235:genetics*; D001483:Base Sequence; D020552:Comet Assay; D004249:DNA Damage; D017931:DNA Primers; D005260:Female; D005753:Gastric Mucosa / Q000378:metabolism*; D005838:Genotype; D016480:Helicobacter pylori / Q000235:genetics*; D006801:Humans; D008297:Male; D008875:Middle Aged
D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D017931:DNA Primers; C408644:IceA2 protein, Helicobacter pylori; C074689:VacA protein, Helicobacter pylori; C080866:cagA protein, Helicobacter pylori; C405087:iceA1 protein, Helicobacter pylori