Relevent Study On The Relationship Between Gene Polymorphisms And The Susceptibility Of EBV Related Tumor Genes

Objective:To investigate the changes of polymorphism sites before and after EBV genome transfected into AGS.And to investigate Kinesin superfamily protein 21B(KIF21B)(rs2297911),Discs large homolog 5(DLG5)(rs1058198),small nuclear RNA-activating protein complex(SNAPc)(rs3812561)and microtubule-associated protein 9(MAP 9)(rs1058992)polymorphisms in 100 normal controls(NC)and 400 patients with cancer,including EBV-associated/-negative gastric cancer(EBVa/nGC),EBV-associated/-negative nasopharyngeal carcinoma(EBVa/nNPC)and E BV-associated/-negative lymphoma(EBVa/nL).Methods:①High throughput sequencing technique was used to detect the changes of polymorphism sites before and after EBV genome transfected into AGS cells(AGS-EBV).②Genes with different polymorphism sites in AGS and AGS-EBV cell lines were classified by FunRich,an open access network tool.③Four sites,KIF21B(rs2297911),DLG5(rs1058198),SNAPC4(rs3812561)and MAP 9(rs1058992),were selected and genotyped by Agena MassArray system.④All genotyping data was analyzed by chi-square test,and non-conditional Logistic regression was used to calculate odds ratio(OR).P≤0.05 was considered statistically significant.SPSS 21.0 software was used for all statistical analysis.Results:①In AGS and AGS-EBV cells,the distribution of gene SNP sites was mainly in non-coding region,while the distribution of SNP sites in exon coding region,3’ UTR,intergene region,5’ UTR,downstream region,upstream region and splicing region were decreased successively.By comparing the SNP sites of the two groups of cell lines,we screened out the SNP sites with genotype differences between AGS-EBV clones and AGS cell lines.The distribution proportion of the different SNP loci was roughly in line with the overall proportion,with non-coding SNP loci as the main one and no splicing SNP loci.②A total of 928 different SNP sites was detected by high-throughput sequencing.The above-mentioned SNP gene involved in 178 cell components and participated in 37 biological processes.The genes contained 253 protein domains and 773 biological pathways.③KIF21B(rs2297911),DLG5(rs1058198),SNAPC4(rs3812561)and MAP9(rs1058992)were all consistent with HWE equilibrium(rs2297911:χ2=1.225,P>0.05;rs3812561:χ2=1.457,P>0.05;rs1058198:χ2=0.116,P>0.05;rs1058992:χ2=0.085,P>0.05),indicating that the selected control samples were from a genetically balanced population.④EBVaL was significantly different from the control group in genotype distribution and allele distribution of rs2297911 in KIF21B gene(P<0.05).G allele is the risk factor of EBVaL(P=0.009,OR=1.872,95%CI:1.169～2.998).Compared with EBVaL,the genotype distribution and allele frequency of KIF21B(rs2297911)were different(P<0.05).In the recessive model of G,the GG genotype frequency of EBVaL was higher than that of EBVaNPC and EBVnNPC(P=0.013,OR=2.125,95%CI:1.169～3.864;P=0.047,OR=4.444,95%CI:1.101～17.939).There were also significant differences in G alleles between EBVaL and NPC(including EBVaNPC and EBVnNPC)(P=0.005,OR=1.961,95%CI:1.215～3.163;P=0.009,OR=3.241,95%CI:1.297～8.097);There was no significant difference in genotype distribution and allele frequency between the other groups(P>0.05).⑤EBVaGC was significantly different from EBVnGC in terms of genotype distribution and allele frequency of MAP9(rs1058992)(P<0.05,OR=1.904,95%CI=1.141～3.179).In CC recessive model,EBVaGC was significantly different from EBVnGC group(P=0.006,OR=2.558,95%CI=1.316～5.010).EBVnGC was significantly different from the NC group in the frequency of C allele(P<0.05,OR=1.724,95%CI=1.036～2.870).There was no significant difference in genotype distribution and allele frequency between the other groups(P>0.05).⑥SNAPC4(rs3812561)and DLG5(rs1058198)had no significant difference in genotypes or alleles between the patients and the control group(all P>0.05).Conclusion:①EBV integration into the host genome can lead to a large number of SNPs in AGS cells,suggesting that EBV is involved in the process of changing gene structure.②KIF21B(rs2297911)G allele was EBVaL predisposition risk factor in recessive model and dominant model.③Compared with EBVnGC group,EBVaGC showed significant difference in genotype distribution and allele frequency of MAP9(rs1058992)locus.CC genotype and C allele are risk factors for EBVaGC;EBVaGC group had a significantly higher frequency of C allele,a risk factor for EBVnGC,than the normal control group.④SNAPC4(rs3812561)and DLG5(rs1058198)polymorphism had no significant correlation with EBV-related tumor susceptibility.