Correlation Study Of Helicobacter Pylori Infection, P53 Gene Arg72Pro Single Nucleotide Polymorphism And Susceptibility To Gastric Cancer In Qinghai Region

Objective:1,To investigate the incidence rate of Helicobacter pylori infection and other factors among the healthy people and the gastric carcinoma patients in Qinghai province, as well as the relation between the P53Arg72 Pro polymorphism and the susceptibility to gastric cancer in Qinghai region.2,To explore the interaction between Hp,nationality and other factors and the different genotype of P53 gene.3,To discuss the impact of the single nucleotide polymorphism of P53 gene on the location of gastric cancer.Methods:To determine the infection rate of Hp with either the 14 C urea breath test(14C-UBT) or the rapid urease test(RUT).To detect the polymorphism of P53 Arg72 Pro SNP through the real-time PCR(Taq Man) between the patients with gastric carcinoma and the normal individuals in the region of Qinghai.We analyzed the results of each genotype,Hp infection, ethnicity, smoking and drinking history and the risk of gastric cancer.Results:The rates of Hp infection have a significant difference between the carcinoma patients and the healthy control group(42.2 % Vs 63.1 %, OR=2.338, 95%CI:1.701~3.214).And significant differences existed in smoking,water-drinking, And so on( r <0.05).Three genotypes of P53Arg72 Pro were identified:Arg/Arg, Arg/Pro and Pro/Pro.The frequencies of these three genotypes were 11.3%,58.9% and 29.8% for the patients with gastric,and the corresponding values were 16.4%,49.2% and 34.3% for the control group.Compared with Arg/Arg genotype,the results of Pro/Pro genotype showed a significant difference between cancer patients and normal controls(The value of OR is 1.256, 95%CI:1.057~2.845).The frequencies of Arg alleles were 35.1% versus 41.0% for the patients with gastric and the group of healthy people while Pro alleles values were 64.9% versus 59.0%,which showed a significant difference( r <0.05).The risk of gastric cancer for the carriers with Pro alleles was 128% of the value for the control group.To analysis the allele frequencies of p53Arg72 Pro in gastric cancer group and control group with different factors like smoking or nonsmoking and ethnic groups,showed that for the people carrying Pro homozygous genotype who are nonsmoking or he/she is Han,the risk of gastric cancer was higher.Comparing the risk of gastric cancer between Pro/Pro and Arg/Arg,between Arg/Arg and Pro/Pro+Pro/Arg,it was found that either Han people carrying P53 allele of Pro(Arg/Pro+Pro/Pro),the probability of gastric cancer was higher.The result showed that there was no correlation between the gastric cancer location and the distribution of P53 Arg72 Pro genotype( r =0.259).Conclusions:The detection rate of Hp in gastric cancer group is high.The p53Arg72 Pro polymorphism shows no significant relation with the infection rate of Hp among the carcinoma patients.The polymorphism of P53Arg72 Pro is correlated with the risk of gastric cancer in Qinghai province.The risk of gastric cancer is remarkably higher in Han people who carries P53 Pro alleles.No correlation is found between the polymorphism of P53Arg72 Pro and the occurring sites of gastric cancer.