Association Between Cyclooxygenase-2Gene Polymorphisms And Chronic Periodontitis In Ningxia Hui And Han Populations

Objective Cyclooxygenase-2（COX-2）plays a critical role in the synthesis ofinflammatory mediators prostaglandin E2(PGE2). PGE2, Which is considered to be animportant mediator of tissue destruction in periodontitis. The aim of this subject was to studythe association between COX-2-765G/C、-1195G/A gene polymorphisms and susceptibility tochronic periodontitis (CP) in Ningxia Hui and Han populations and to explore the differencesof the genotypes and alleles between the two nationalities.Methods132cases of chronic periodontitis(CP)and138cases of healthy controls(HC)in Hui nationality,141cases of chronic periodontitis(CP)and146cases of healthycontrols(HC) in Han nationality,Which were recruited accordanced with the diagnosticcriteria and inclusion criteria for the study. The genotypes of the COX-2-765G/C and-1195G/A were detected by polymerase chain reaction-restriction fragment lengthpolymorphism (PCR-RFLP), the DNA was extracted from venous blood. The distribution ofgenotypes and alleles frequencies between each groups were compared by case-controlmethods.Results (1) COX-2-765: We found3genotypes(GG、GC and CC) of COX-2-765in allgroups. The difference in the frequencies of COX-2-765genotypes and alleles was no statisticsignificance between the CP group and HC group in Hui populations(P=0.533and P=0.253,respectively); In Han populations, the difference in the frequencies of genotypes and alleleswas no statistic significance between the CP group and HC group(P=0.843and P=0.572,respectively). But the difference in the frequencies of COX-2-765genotypes and alleles has statistic significance between the Hui CP group and Han CP group(P=0.014and P=0.002,respectively),the GC and CC genotypes in Hui CP group was higher than in Han CP, andcompared with the Han CP group (9.93%),the frequency of the allele C was significantlyhigher in Hui CP group(19.32%). The difference in the frequencies of genotypes and alleleshas statistic significance between the Hui HC group and Han HC group(P=0.047and P=0.01,respectively), and the frequency of the allele C in Hui HC group was also higher than in HanHC.(2)COX-2-1195: The rates of G/A mutation in COX-2-1195G/A were higher in eachgroup.The difference in the frequencies of COX-2-1195genotypes and alleles has statisticsignificance between the CP and HC in Hui populations(P=0.006and P=0.014, respectively),and compared with HC group,the frequency of the allele A was significantly higher in CPgroup; In Han populations, the difference in the frequencies of genotypes and alleles hasstatistic significance between the CP group and HC (P=0.009and P=0.015, respectively), andthe frequency of the allele A in CP group was also higher than in HC. The difference in thefrequencies of COX-2-1195genotypes and alleles was no statistic significance between theHui CP group and Han CP group (P=0.428and P=0.327, respectively).Conclusion (1) COX-2-765G/C polymorphism may be not associated with thesusceptibility of chronic periodontitis in Ningxia Hui and Han populations. The frequencies ofCOX-2-765genotypes and alleles has difference between Hui CP group and Han CP group, Hui HCand Han HC in Ningxia,but the results needs further investigation.(2) COX-2-1195G/Apolymorphism may be associated with the susceptibility of chronic periodontitis in NingxiaHui and Han populations.