| Background:According to the Global Cancer Survey data of the Latest data,biliary cancer has more than 219,000 new cases and more than 165,000 deaths per year.The cancer data in China shows that biliary cancer is newly issued more than 52,800 cases each year,and more than 40,700 deaths,accounting for the world 1/4.Biliary tract cancer(BTC) includes cholangiocarcinoma(CCA) and gallbladder carcinoma(GBC).The incidence of cholangiocarcinoma is similar to that of men and women,and the incidence and mortality of gallbladder cancer are higher than that of men.The onset of bile duct cancer is concealed and there is no clear direct cause,but hepatic trematode infection,primary sclerosing cholangitis,gallstones and other biliary inflammation are related to the occurrence and development of bile duct cancer.Apolipoprotein B gene editing catalytic polypeptide-like enzyme(APOBEC) can deaminate cytosine(C) to uracil(U) in chronic inflammatory state.There is literature support that APOBEC cytidine deaminase mutagenesis patterns are prevalent in human cancers.There is a uracil-DNA glycosylase(UNG) in the body,which is a promoter of the regulatory repair pathway and recognizes the C>U mutation caused by the APOBEC family.Therefore,there is a balance between the APOBEC family and UNG.The level of mutation reached a steady state.Exome sequencing results show that there are mainly APOBEC mutation tags in biliary cancer.Objective:To analyze whether single nucleotide polymorphism(SNP) at four sites of APOBEC3A/B(rs12157810,rs12628403 and rs2267401) and UNG(rs3890995) affects the development of biliary tract inflammation,cholangiocarcinoma and gallbladder carcinoma,and between SNP sites.Functional verification was performed on statistically significant SNP loci.To explore the genetic factors of the occurrence of biliary system diseases in China,and provide a scientific basis for the early prevention of biliary cancer.Methods:This study used a case-control study design that included 3,242 subjects,including1,240 healthy controls,808 patients with biliary tract inflammation,and 1194 patients with biliary tract cancer(741 patients with cholangiocarcinoma and 453 patients with gallbladder cancer).Four SNPs were detected and classified by fluorescent probe real-time quantitative PCR.Hardy-Weinberg genetic balance was tested by Microsoft Excel 2016,Sanger sequencing was used to verify the typing results,and ?~2 test and binary logistic regression model were used to study the role of APOBEC3A,APOBEC3B,UNG genetic polymorphisms and their interactions in the development of biliary system cancer.To make assumptions.SNP site function verification was performed using a dual fluorescence reporter monitoring system,and paired t-test was used for statistical analysis.Results:1.Relationship between APOBEC3A,APOBEC3B and UNG gene polymorphisms and biliary system diseases(1)Relationship between APOBEC3A/3B and UNG gene polymorphisms and biliary tract inflammation and biliary tract cancerCompared with AA genotype,rs12157810 CC genotype could significantly reduce the risk of biliary inflammation in healthy people(CC:AOR=0.582,95%CI 0.432-0.785,P<0.001).The CC genotype of Rs12157810 SNP locus was a protective factor for the occurrence of biliary cancer in healthy people(CC:AOR=0.473,95%CI 0.366-0.612,P<0.001).Compared with healthy people,the distribution of rs12628403 and rs3890995 low-frequency genotypes in biliary inflammation group and biliary cancer group had no difference.As for rs2267401,according to the characteristics of deletion mutation,we divide it into two cases.One is that rs12628403 AA APOBEC3B has no deletion mutation.Rs2267401 GG increased the risk of biliary cancer in healthy people(AOR=1.829,95%CI 1.242-2.693,P=0.002).In the second case,a single base deletion mutation occurred in rs12628403 AC APOBEC3B.Using T genotype as control group,rs2267401 G increased the risk of cancer in healthy controls(AOR=1.410,95%CI1.141-1.744,P<0.001).(2)Effects of gender factors on biliary system diseases of APOBEC3A/3B and UNG polymorphismsCholangiocarcinoma was divided into cholangiocarcinoma and gallbladder cancer.It was found that the dominant model of rs2267401(TG+GG) had more obvious protective effect on male cholangiocarcinoma than on female cholangiocarcinoma(TG+GG:AOR=0.612,95%CI 0.415-0.902,P=0.013;TG+GG:AOR=0.815,95%CI0.494-1.343,P=0.421) in male cholangiocarcinoma VS health control female cholangiocarcinoma.Dominant model(TG+GG) and partial deletion of G genotype had higher risk for women than men(male gallbladder cancer VS health control TG+GG:AOR=1.926,95% CI 1.112-3.335,P=0.019;female gallbladder cancer VS health control TG+GG:AOR=2.322,95% CI 1.221-4.416,P=0.010;male gallbladladder cancer VS health control G:AOR=1.814,95% CI 1.232-2.670,P=0.003;female gallbladladder cancer VS health control G AOR=2.618,95% CI 1.656-4.140,P<0.001.The low-frequency genotypes of rs12628403 and rs3890995 had no difference between men and women.The low-frequency genotypes of rs12157810 significantly reduced the risk of biliary tract disease in healthy people,but there was no significant difference between men and women.(3)Interaction of gene polymorphisms of APOBEC3A and APOBEC3BThe rs2267401 locus dominant model(TG+GG)and the rs12157810 dominant model(AC+CC)have significant synergistic interactions in the development of biliary tract inflammation and cholangiocarcinoma(biliary inflammation vs healthy controls:AOR=0.439 95% CI 0.314-0.614,P<0.001;cholangiocarcinoma vs healthy controls:AOR=0.301 95% CI 0.211-0.431 P<0.001).In gallbladder carcinoma,there is also an interaction between the rs2267401 locus dominant model(TG+GG)and the rs12157810dominant model(AC+CC)(gallbladder cancer vs healthy controls:AOR=0.286 95%CI0.184-0.444 P<0.001).2?The Functional of rs12157810 and rs2267401 featuresFunctional experiments showed that the C genotype of rs12157810 enhanced APOBEC3A promoter activity compared with A genotype.Compared with T genotype,rs2267401 G genotype decreased APOBEC3B promoter activity in cholangiocarcinoma and increased APOBEC3B promoter activity in gallbladder cancer.conclusion:1.The rs12157810 C allele of the SNP locus in the APOBEC3A promoter region can reduce the risk of biliary system diseases.2.APOBEC3B promoter region SNP locus rs2267401 G allele can reduce the risk of cholangiocarcinoma,and increase the risk of gallbladder cancer.The rs2267401 G allele is more effective in reducing the risk of cholangiocarcinoma in men,and the risk of increasing the incidence of gallbladder cancer in women is more obvious. |
PDF Full Text Request