DNA damage and repair in Helicobacter pylori-infected gastric mucosa cells.
Helicobacter pylori is a common human pathogen and its infection is believed to contribute to gastric cancer. Impaired DNA repair may fuel up cancer transformation by the accumulation of mutation and increased susceptibility to exogenous carcinogens. To evaluate the role of infection of H. pylori in DNA damage and repair we determined: (1) the level of endogenous basal, oxidative and alkylative DNA damage, and (2) the efficacy of removal of DNA damage induced by hydrogen peroxide and the antibiotic amoxicillin in the H. pylori-infected and non-infected GMCs. DNA damage and the efficacy of DNA repair were evaluated by the alkaline single cell gel electrophoresis (comet assay). Specific damage to the DNA bases were assayed with the DNA repair enzymes formamidopyrimidine-DNA glycosylase (Fpg) recognizing oxidized DNA bases and 3-methyladenine-DNA glycosylase II (AlkA) recognizing alkylated bases. The level of basal and oxidative DNA in the infected GMCs was higher than non-infected cells. H. pylori-infected GMCs displayed enhanced susceptibility to hydrogen peroxide than control cells. There was no difference between the efficacy of DNA repair in the infected and non-infected cells after treatment with hydrogen peroxide and amoxicillin. Our results indicate that H. pylori infection may be correlated with oxidative DNA damage in GMCs. Therefore, these features can be considered as a risk marker for gastric cancer associated with H. pylori infection and the comet assay may be applied to evaluate this marker.
Arabski
Michal
M
Department of Molecular Genetics, University of Lodz, Banacha 12/16, 90-237 Lodz, Poland.
Klupinska
Grazyna
G
Chojnacki
Jan
J
Kazmierczak
Pawel
P
Wisniewska-Jarosinska
Maria
M
Drzewoski
Jozef
J
Blasiak
Janusz
J
D000328:Adult; D000368:Aged; D000478:Alkylation; D004249:DNA Damage / Q000502:physiology*; D004260:DNA Repair / Q000502:physiology*; D005260:Female; D005753:Gastric Mucosa / Q000378:metabolism / Q000382:microbiology*; D016481:Helicobacter Infections / Q000378:metabolism*; D016480:Helicobacter pylori; D006801:Humans; D008297:Male; D008875:Middle Aged; D010084:Oxidation-Reduction; D013997:Time Factors; D014508:Urea / Q000378:metabolism
D014508:Urea