The Correlation Of The Expression Of MGMT And MGMT Methyltransferase In Gliomas With Tumor Grade

Background:Glioma is the most common refractory intracranial tumors, accountingfor50-60%of intracranial tumors, glioma diffuse infiltrative growth pattern, and withno obvious boundaries to surrounding normal brain tissue, operation is difficult to cutthe tomor completely,The current treatment of glioma is surgical resection,radiotherapy and chemotherapy etc., but gliomas refer to recur, so the prognosis ispoor, with an average survival period is shorter, how to improve and enhance thesurvival of patients, control of tumor relapse, has been the focus of research. Nowthere are biological diagnosis of cancer molecular diagnostics, cancer treatment is alsomore inclined to individualized treatment, O6-methylguanine-DNA methyltransferaseexpression in reference to drug resistance, MGMT promoter methylation status is amajor factor in determining MGMT expression in gliomas and is likely to affect theprognosis of the patient, therefore the treatment of gliomas, should not only based onthe pathological grade tumors then desirable, but also joint relationship of tumor andtumor histological grade of between molecular biology has become a new way to treatgliomas.Objective:The study use immunohistochemistry (Immunohistochemistry, IHC), todetect the expression of MGMT in gliomas,use methylation-specific PCR (methylation specificPCR, MSP) method to detect glioma MGMT promoter methylation circumstances,this study was to investigate the O6-methylguanine-DNA-methyltransferase (MGMT) methylation and relationships with pathological grade gl iomas.Methods:The subjects were different levels of paraffin-embedded specimens of42glioma patients,detected MGMT methylation at different levels of expression ingliomas, analyze different pathological levels of MGMT methylation associatedwith glioma. Correlation between MGMT and MGMT promoter methylationbetween. Medical statistical analysis using SPSS16.0computer software fordata analysis.Results:1. In42cases of glioma tumor samples, MGMT expression of24cases, theoverall positive expression rate:57.14%, at different pathological levels, Ⅰgradegliomas positive rate:44.44%Ⅱgrade gliomas positive rate:54.54%, Ⅲgradegliomas positive rate:55.55%, Ⅳ grade gliomas positive rate:69.23%rate ofMGMT protein expression with tumor pathology elevated levels tended to increase,but the statistical analysis of the differences between pathological grade gliomas, nostatistical significance (P>0.05).2. In42cases of glioma tumor samples, MGMT promoter methylation as21cases, methylation overall expression rate:50%, at different levels in differentpathological expression, Ⅰgrade glioma MGMT promoter methylation was:77.78%,Ⅱgrade glioma MGMT promoter methylation was:72.72%, Ⅲgrade glioma MGMTpromoter methylation was:33.33%, Ⅳgrade gliomas MGMT promoter methylationwas:23.1%statistically analyze the differences MGMT promoter methylation ratesbetween different pathological grade of glioma, had statistically significant (P<0.05).3. In42cases of glioma tumor samples,24cases of MGMT protein expression inglioma tissues, eight cases of glioma MGMT gene promoter methylation, the positiverate was33.33%,24cases of MGMT protein negative expression in glioma tissues,13cases of glioma MGMT gene promoter methylation, the positive rate was72.22%,with a Spearman correlation coefficient analysis: P <0.05.4.42cases of glioma tumor samples, MGMT protein expression was notrelated.to the patient’s age and gender. Conclusions:1. MGMT protein expression rate of different pathological level gliomasis different, rates of MGMT protein expression with pathological grade gliomasincreased upward trend, but statistical analysis showed no significant difference, soMGMT protein expression and pathological grade gliomas had no correlation.2. Different pathological grade glioma MGMT gene promoter methylation rate isdifferent, statistically analyze the difference was statistically significant, and thereforeMGMT gene promoter methylation rate and pathological grade gliomas negativecorrelation.3. In gliomas, MGMT protein expression and MGMT gene promoter methylationwas negatively correlated statistically significant difference test.4.Gliomas MGMT protein expression was unconcerned with the patient’s ageand sex, so in clinical develop individualized treatment plan for the patient, the sex,age is not a factor.