The Correlation Of The Expression Of MGMT And P53 In Human Brain Gliomas With Tumor Grade Or Prognosis

Purpose:To explore the correlation of the expression of MGMT and P53 in human brain gliomas with tumor grade or prognosis.Materials and Methods:Histopathologically confirmed glioma tissues were collected from 133 patients for surgical treatment between January 2002 and December 2002 at the Neurosurgery Department of Huashan Hospital of Fudan University. Among 133 glioma cases,13 were WHO grade I,50 gradeⅡ,30 gradeⅢand 38 grade IV. The expression of MGMT and P53 in glioma tissues was detected using immunohistochemistry methods and its correlation with tumor grade or prognosis was also analyzed.Results:(1) Of 133 human glioma tissues,57.1%show positive expression of MGMT.30.8%,60.0%,60.0%, and 60.0% indicate MGMT-positive expression for grade I,Ⅱ,Ⅲ, andⅣ, respectively. There is no statistically significant difference between the expression of MGMT or its intensity in different grades of gliomas (p= 0.158,0.138, respectively).(2) The 1-,2-,3-,4-,5-and 6-year survival rates of MGMT-negtive group are 96.5%,84.2%,77.2%,73.7%,71.9%, 66.7%respectively; The 1-to 6-year survival rates of MGMT-weakly positive group are 87.3％,69.1％,58.2％, 49.1％,38.2％,30.9％respectively and The 1-to 6-year surviVal rates Of MGMT-pOSitiVe group are 61.9％,38.1％,33.3％,33.3％,28.6％,28.6％respectively. The survival rates decrease With the increase of Intensity of MGMT expression by Kaplan-Meier survival curve (P=1.07*10-6).(3)Of 133 human glioma tissues,67.7％show positive expression of p5353.8％,66.0％,70.O％,72.5％indicate P53-positive expression for grade I,Ⅱ,Ⅲ,andⅣV,respectively. There is no statistically signifficant difference between the expression of P53 in different grades ofgliomas(P=0.306),but the intensity of expression of P53 are statistically signifcant different(P=0.032)and it shows a positive correlation (R=0.187)(4)The 1-,2-,3-,4-,5-ang6-year survival rates of P53negtive group are 95-3％,81.4％,74.4％,65.1％,62.8％,60.5％respectively；The 1-to 6-year surviVal rates Of P53-weakly positive group are 85.7％,78.6％,71.4％,64.3％,57.1％,57.1％respectively；The 1- to 6-year surviVal rates of P 53. positive group are 80.8％,69.2％,69.2％,46.2％,46.2％,46.2％respectively alld The 1-tO 6-year surviVal rates of P53-sttongly positive group are 58.3％,38.9％,30.6％,27.8％,22.2％,22.2％respectively. The survival rates decrease with the increase of intensity of P53 expression by Kaplan-Meier survival curve (P=2.08* 10") (5)There is a weak inverse correlation between the intensity of MGMT expression and the intensity of P53 expression (R=-0.13184 P=0.065)Conclusions:(1) Our findings suggest that the expression of MGMT is correlated to glioma patient survival, not with tumor grade. The intensity of MGMT expression in glioma tissues is reversely related to the survival time of patients. (2) The expression of p53 is not related to tumor grade; however, the intensity of p53 expression increases with the tumor grade, and is reversely associated with the survival time of patients. (3) Although our results suggest a probable existence of negative correlation between MGMT and p53 expression, its definite significance and mechanisms is still unclear. The exact role of MGMT and p53 expression and their interaction mechanisms in gliomas should be further investigated in the future studies. (4) It should provide a useful predictor of glioma prognosis to detect the expression of MGMT and p53 in gliomas.