[The correlative analysis of indefinite dysplasia and dysplasia, and its p16 methylation in human gastric mucosa with Helicobacter pylori infection].
OBJECTIVE
To compare the CpG island methylation status of p16 in subjects with gastric indefinite dysplasia or dysplasia, and investigate its association with exposure factors.


METHODS
Methylation status of p16 was determined by methylation specific PCR method and denaturing high-performance liquid chromatography analysis in 223 indefinite dysplasia and 130 dysplasia from Linqu County in Shandong Province, an area with high GC mortality rates. Multivariable analysis was used to analyze the relationship between p16 methylation and age, gender, cigarette smoking, alcohol drinking, and Helicobacter pylori infection.


RESULTS
The methylation frequency of p16 in indefinite dysplasia was not significantly different from that of dysplasia (28.3% vs 24.6%, P=0.46). No significant association was found between p16 methylation and age, gender, cigarette smoking, and alcohol drinking. In dysplasia, the association between p16 methylation and Helicobacter pylori infection was close to the statistical significance by univariate analysis that the relative risk of p16 methylation of the infected subjects(n=93) is higher than that of the uninfected subjects (n=37)(OR=2.62, 95% CI: 0.92 to 7.43, P=0.07).But by multivariate analysis, there was no association between them(P=0.11).


CONCLUSIONS
The frequency of p16 methylation in gastric mucosa of indefinite dysplasia was similar to that of dysplasia. p16 methylation status was not associated with age, but might be significantly associated with Helicobacter pylori infection.
Department of Cancer Epidemiology, Peking University School of Oncology, Beijing, China.
Cai Xuan
CX
Dong
Da Jun
da J
Deng
Jing
J
Zhou
Lian
L
Zhang
Jun Ling
JL
Ma
Kai Feng
KF
Pan
Wei Cheng
WC
You
D000328:Adult; D000368:Aged; D018899:CpG Islands / Q000235:genetics; D019175:DNA Methylation; D005260:Female; D005753:Gastric Mucosa / Q000378:metabolism* / Q000473:pathology; D019942:Genes, p16; D016481:Helicobacter Infections / Q000235:genetics* / Q000473:pathology; D016480:Helicobacter pylori; D006801:Humans; D008297:Male; D008875:Middle Aged; D011230:Precancerous Conditions / Q000235:genetics / Q000382:microbiology; D011401:Promoter Regions, Genetic; D013274:Stomach Neoplasms / Q000235:genetics* / Q000382:microbiology