PROGNOSTIC VALUE OF COMBINED IMMUNOHISTOCHEMICAL EXPRESSION OF BMI1 AND EZH2 IN ASTROCYTOMA

Abstract

Background: Although current improvements in surgery, chemotherapy and radiotherapy, the still survival of astrocytoma’s patient is poor. It is assumed that the combined expression of BMI1 and EZH2 may be associated with malignant transformation of astrocytomas and also it may reveal the biological aggressiveness of this disease.

Aim of work: assessment the value of the combined immunohistochemical expression of BMI1 and EZH2 and their correlation with the clinicopathological characters and prognosis in astrocytoma patient.

Subjects & Methods: BMI1 and EZH2 expressions were evaluated using immunohistochemical staining in 70 patients 40 cases with astrocytomas and 30 cases of non-neoplastic brain tissue. The relationship between their expressions and clinicopathological factors were analyzed.

Results: A significant difference (P<0.002) between expression ofBMI1 and EZH2 in astrocytoma compared to corresponding non-neoplastic brain tissue. A significant association was found between high expression ofBMI1 and EZH2 and WHO high grades in astrocytomas. No statistically significant association was found betweenBMI1 or EZH2 with gender of patients, age at diagnosis, site and size of tumor (P > 0.05). The spearman correlation analysis revealed a significant positive association betweenBMI1 and EZH2 expressions (r = 0.311; P=0.05) revealing direct relationship betweenBMI1 and EZH2.

Conclusions: BMI1 and EZH2 were involved in astrocytoma malignant transformation and poor prognosis in astrocytoma particularly glioblastoma.

Keywords: BMI1, EZH2, astrocytoma, PcG, glioblastoma and GSCs.