Correlation Between DNA Hypermethylation And HLA-C*07 MRNA Expression In HLA-C*07 Intron Ⅶ Of Patients With Endometriosis

Purpose:The DNA methylation of HLA-C*07 intron VII in eutopic endometrium,ectopic endometrium(experimental group)and non-endometriosis endometrium(control group)and the expression level of HLA-C*07 mRNA were detected to compare the differences among the groups.The purpose was to study the correlation between DNA methylation of HLA-C*07 intron VII and endometriosis.The significance of this study was to explore the mechanism of endometriosis from epigenetics.Methods:The eutopic endometrium and ectopic endometrial tissue were collected from the Shanghai East Hospital from April 2017 to September 2018 and confirmed by pathological diagnosis as ovarian endometriosis.The endometrium of women of childbearing age who received the ring and took the ring at the same time as the control group.The ectopic endometrium,eutopic endometrium and control endometrial tissue DNA of the experimental group were extracted,and the transformed genomic DNA was treated with bisulfite to detect HLA-C*07 by bisulfite sequencing.The methylation status of VII was further investigated;the total RNA of the two groups of endometrial tissues was further extracted,and the expression level of HLA-C*07 mRNA was detected by real-time quantitative polymerase chain reaction(qRT-PCR)using GAPDH gene as an internal control.Statistical analysis was performed using SPSS 20.0 software to compare the methylation degree of HLA-C*07 intron VII region and the expression of HLA-C*07 mRNA between the eutopic endometrium,ectopic endometrium and control group.Normally distributed measurement data was analyzed using one-way ANOVA;For the numeration data,ⅹ~2 test was used to compare the methylation rate of HLA-C*07 intron VII DNA between groups;Nonparametric test analysis did not conform to normal distribution data;Correlation between HLA-C*07 intron VII DNA methylation and HLA-C*07 mRNA levels was analyzed by Spearman correlation test.P<0.05 was considered statistically significant.Results:1.The methylation rate of HLA-C*07 intron VII DNA in the eutopic and ectopic endometrium of the experimental group was significantly higher than control group.2.Comparison of DNA methylation rate of HLA-C~*07 intronⅦand HLA-C*07mRNA expression between groups2.1 The methylation level of HLA-C*07 intron VII region in ectopic endometrium of experimental group was significantly higher than that in the control group,and the expression level of HLA-C*07 mRNA in ectopic endometrium of experimental group was significantly higher than that in the control group(P<0.05).2.2 The methylation level of HLA-C*07 intronVII region in the experimental group was significantly higher than that in the control group,and the expression level of HLA-C*07 mRNA in the experimental group was significantly higher than that in the control group(P<0.05).2.3 The methylation level of ectopic endometrium in HLA-C*07 intronVII region was similar to eutopic endometrium in experimental group;the expression level of HLA-C*07 mRNA in ectopic endometrium was similar to eutopic endometrium in experimental group;the difference was not statistically significant(P>0.05).3.Correlation between methylation degree of HLA-C*07 intron VII and HLA-C*07mRNA expression in endometriosis:The methylation degree of HLA-C*07 intron VII was closely related to the expression level of HLA-C*07 mRNA in the eutopic endometrium of the experimental group(r=0.843,P=0.009).In the ectopic endometrium of the experimental group,the methylation degree of HLA-C*07 intron VII was closely related to the expression level of HLA-C*07 mRNA(r=0.746,P=0.034).Conclusion:The hypermethylation of HLA-C*07 intron VII region in endometriosis patients regulates the expression of HLA-C*07 mRNA.HLA-C*07intronVII hypermethylation can be used as a new biomarker for early prediction and diagnosis of endometriosis.