Methylation Of PpENK、EDNRB Gene And Protein Expression In Glioma

Objective：The tumor suppressor gene of the abnormal methylation is one of theimportant mechanisms of genetics. It plays an important role in the occurrence anddevelopment of the glioma.We extract the preoperative patient’s serum and study on themethylation of the gene of ppENK、EDNRB.To study the relationship of themethylation of ppENK、EDNRB and protein expression in glioma.Methods：The serum samples come from the First Affiliated Hospital of Anhui MedicalUniversity， Department of neurosurgery from2010to2012. Male21cases, female25cases, age19~76years old, average38.2years old. According to the pathology ofWHO grade,31cases in gradeⅠ-Ⅱ,and15cases in grade Ⅲ-Ⅳ.It contains25cases of astrocytoma,13cases of glioblastoma,5cases of oligodendroglioma and3cases of ependymoma but2cases of the normal brain tissues as comparation. PCR andBSP was adopted to investigate the promoter frequency of these genes in46cases ofglioma tissue.The ppENK、EDNRB expression in46glioma specimens was examinedby immunohistochemistry method. Analyse the correlation between the degree ofmethylation, protein expression and clinical data.The results：After examinating the patient‘s serum samples and tumor tissue from this group,thereare44cases in accordance with the DNA conditions.With nPCR amplification，43/40cases were successful in methylation sequencing. We don’t detect the methylation of ppENK、EDNRB gene in2cases of normal brain tissue. In patients with glioma, thefrequency of methylation in ppENK、EDNRB was44.2%（19/43）、22.5%（9/40）. Therate of gene promoter methylation in grades Ⅰ~Ⅱ gliomas was significantly lower thanthat in grades Ⅲ~Ⅳ gliomas (p <0.05). The methylated protein expression positive rateof57.8%（11/19）、55.5%(5/9), unmethylated protein expression was87.5%(21/24)，90.3%(28/31). There were no obvious correlation between ppENK、EDNRB gene andthe patients’s age, sex, tumor pathological type and other factors. Kaplan-Meier survivalcurve analysis showed that the unmethylaed Survival of the ppENK、EDNRB gene werelonger than the gene of methylation significantly.Conclusion ppENK、EDNRB promoter(CpG island)hypermethylation exists inglioma, which may correlates with the occurrence of glioma. The rate of methylation ofthe gene was negatively correlated with protein expression. The detection of the gene ofmethylation status may provide a new method for the diagnosis of brain gliomas andmay provide an important theoretical basis for gene therapy in brain tumor.