[Mitochondrial DNA mutations in gastric endothelial cells induced by extract of helicobacter pylori in vitro].
OBJECTIVE
To investigate the relationship between the helicobacter pylori (HP) infection and the genetic instability of mitochondrial DNA (mtDNA) in human gastric adenocarcinoma epithelial cells (AGS).


METHODS
After treated with extracts of HP11638 (CagA+, VacA+) or Hp11638 mutant strain (CagA+, VacA-), AGS cells were collected, and mitochondrial DNA was extracted and Cox-I, Cox-II, Cox-III, ATPase6, ATPase8 and Cytb genes and the D-Loop region were amplified by PCR and then sequenced.


RESULTS
The mutation rates of the mtDNA in AGS cells were correlated with the extracts of the two HP strains in a concentration- and time-dependent manner. But the mtDNA mutation rate in AGS cells treated with the HP11638 extract was higher than that treated with the Hp11638 mutant extract. Total of 616 mutations in D-Loop region were detected, including 489 point mutations, 81 insertions and 46 deletions. Among them, 70.9% (437/616) belonged to GC to AT and AT to GC transition. Seventeen out of 20 (85%) AGS cells treated with extract of HP had mutations in 303PolyC, 16184PolyC and 514CA regions of mtDNA D-Loop. No mutation was detected in Cox-I, Cox-II, Cox-III, ATPase6 and ATPase8 genes, three point mutations were found in the Cytb gene.


CONCLUSIONS
HP can cause the accumulation of mutations in mtDNA, in particular, in the D-Loop region, and the VacA participated in the process.
Luo
Rui-hua
RH
Department of Gastroscopy, Huadong Sanatorium, Wuxi, Jiangsu, 214065 PR China.
Huang
Xue-wen
XW
Shen
Zhong-ze
ZZ
Huang
Li-li
LL
An
Xian-yuan
XY
Zhao
Lan-jing
LJ
D000942:Antigens, Bacterial / Q000494:pharmacology; D001483:Base Sequence; D004272:DNA, Mitochondrial / Q000187:drug effects* / Q000235:genetics; D042783:Endothelial Cells / Q000187:drug effects* / Q000473:pathology; D016481:Helicobacter Infections / Q000150:complications; D016480:Helicobacter pylori / Q000737:chemistry*; D006801:Humans; D009154:Mutation; D013270:Stomach / Q000473:pathology*
D000942:Antigens, Bacterial; D004272:DNA, Mitochondrial