Relationship Between DNMT3B Gene Polymorphisms And Prognosis In Patients With Epithelial Ovarian Cancer

Objective: Most of the patients with epithelial ovarian cancer have no obvious symptoms in the early stage,and there is no specific screening method.About 70% of the patients have developed to the advanced stage at the time of diagnosis.The main treatment for advanced patients is tumor cell reduction surgery and adjuvant chemotherapy based on platinum drugs.Due to the difficulty of early diagnosis of epithelial ovarian cancer and drug resistance in the process of chemotherapy,most patients have tumor metastasis and recurrence within 2 years,and the 5-year survival rate is 20% to 40%.Therefore,the application of specific biomarkers to predict the clinical prognostic risk of epithelial ovarian cancer can improve the survival rate and improve the quality of life of patients.DNA methylation is involved in the regulation of many biological processes in vivo,such as gene expression,gene silencing,DNA damage repair and so on.A number of studies have shown that aberrant methylation of DNA is an important marker in the occurrence,development and drug resistance of tumors.DNMT3 B gene is an important gene in the process of catalysing and maintaining genomic DNA methylation.The single nucleotide polymorphism of this gene may be the key to abnormal methylation of DNA.The purpose of this study was to investigate the relationship between rs2424913 and rs6087990 polymorphisms in the promoter region of DNMT3 B gene and clinical prognosis of patients with epithelial ovarian cancer.Methods:1.Cohort study to analyze the association between single nucleotide polymorphism of DNMT3 B gene and platinum chemosensitivity and clinical prognosis in patients with EOC.Genomic DNA,was extracted by protease K digestion-saturated sodium chloride salting-out method.Rs2424913 and rs6087990 genotypes were detected by polymerase chain reaction-ligase detection reaction.2.SPSS 25.0 software(SPSS Company,Chicago,IL,USA)was used to analyze the data involved in this study.The difference was statistically significant when P<0.05.Results: 1.There were no significant differences in the genotype frequencies of DNMT3 B gene rs2424913 and rs6087990 polymorphisms among different clinical characteristics;2.COX regression model analysis(adjustment for residual lesions after age staging)identified that DNMT3 B rs2424913 SNP was associated with the clinical prognosis of the EOC patients,that is,compared with T/T genotype,the risk of recurrence in patients carrying C/T genotype was significantly increased,3-year and 5-year PFS were significantly shortened(P<0.05,HR=2.73,95%CI=1.24-6.03;HR=3.57,95%CI=1.49-8.51);3.COX regression model analysis(adjustment for residual lesions after age staging)identified that DNMT3 B rs6087990 SNP was not associated with the clinical prognosis of the EOC patients(P>0.05).Conclusions:1.DNMT3 B rs2424913 SNP is related to the clinical prognosis of patients with epithelial ovarian cancer,that is,compared with T/T genotype,carrying C/T genotype may be an independent risk factor for recurrence of EOC patients.2.DNMT3 B gene rs6087990 single nucleotide polymorphism is not associated with the clinical prognosis of EOC patients.