Arylamine N-acetyltransferase: a possible promoter in Helicobacter pylori-related gastric carcinogenesis.
BACKGROUND
The hypothesis of an association between peptic ulcer and infection by Helicobacter pylori in the gastroduodenal tract was suggested by Marshall and Warren in 1984. H pylori infection of the stomach is the most frequent infection in the world and exhibits an age-dependent increase. However, only a very small percentage of those infected develop gastric carcinoma, suggesting that H pylori acts as a cofactor in the pathogenesis of gastric carcinoma. N-Acetyltransferase (NAT) is expressed in uroepithelial cells and colon cytosol, while cytosolic acetyltransferase plays a critical role in susceptibility to arylamine-induced bladder and colon cancer. The presence of NAT activity in H pylori has yet to be determined.


METHODS
NAT activity in H pylori from patients with peptic ulcer was studied using an acetyl coenzyme A (AcCoA) recycling assay and high-pressure liquid chromatography with p-aminobenzoic acid and aminofluorene substrates.


RESULTS
The NAT activities from a number of H pylori samples were found to be 0.68 +/- 0.10 nmol/min/10(10) colony-forming units (CFUs) (intact bacteria); and 0.90 +/- 0.22 nmol/min/mg protein (cytosol) for the acetylation of 2-aminofluorene, and 0.63 +/- 0.06 nmol/min/10(10) CFUs (intact bacteria) and 0.72 +/- 0.24 nmol/min/mg protein (cytosol) for the acetylation of p-aminobenzoic acid.


CONCLUSIONS
These studies show that H pylori has NAT activity, from which we speculate that the bioactivation of food-borne heterocyclic aromatic amines into genotoxic and carcinogenic products in the stomach is a possible promoter in the pathogenesis of gastric cancer.
Hung
C F
CF
Department of Medical Research, China Medical College, Taichung, Taiwan, ROC.
Chung
J G
JG
Liu
S I
SI
Hung
H
H
D000107:Acetylation; D000293:Adolescent; D000328:Adult; D000368:Aged; D001191:Arylamine N-Acetyltransferase / Q000378:metabolism*; D002273:Carcinogens / Q000378:metabolism; D004247:DNA / Q000378:metabolism; D016480:Helicobacter pylori / Q000201:enzymology*; D006801:Humans; D008875:Middle Aged; D013274:Stomach Neoplasms / Q000209:etiology*
D002273:Carcinogens; D004247:DNA; D001191:Arylamine N-Acetyltransferase