GENE-07. INFLUENCE OF EPIGENETIC MODULATION OF THE T-CELL REGULATORS EXPRESSION ON GLIOBLASTOMAS BY HISTONE 3 LYSINE METHYLTRANSFERASE OR DEMETHYLASE ON THE PROGNOSIS OF THE GLIOBLASTOMA PATIENTS

Abstract

Abstract PURPOSE The primary aim of this study is to investigate the expression of the T cell stimulators and inhibitors as well as histone modifying enzymes in the glioblastoma cells. Based on the expression of these proteins, authors estimate the prognostic role in glioblastoma patients and also validate the known prognostic factors. MATERIALS AND METHODS Using 84 FFPE samples of glioblastoma in the pathologic archives at our institute, immunohistochemical staining for T cell stimulators (CD 27, CD 28, CD 137, OX40, ICOS), inhibitors (CTLA-4, PD-1, PD-L1, TIM3, CD200R), histone 3 lysine methyltransferase (MLL4, RIZ, EZH1, NSD2), and histone 3 lysine demethylase (KDM5c, JMJD1a, UTX, JMJD5). RESULTS Median values of the immunohistochemical staining for T cell stimulators and inhibitors were 16.3% of CD27, 10.4% of CD28, 47.5% of CD137, 52.9% of ICOS, 32.2% of OX40, 31.4% of CTLA-4, 7.2% of PD-1, 55.5% of PD-L1, 62.2% of TIM3, and 42.8% of CD200R. In multivariate analysis, increased expression of CD28 (p=0.042), CD137 (p=0.009), EZH1 (p=0.040), and decreased expression of CTLA-4 (p=0.003), PDL-1 (p=0.020) in glioblastoma cells were independently associated with longer OS as well as known prognostic factors such as young age, high KPS, wide extent of resection, PRA class, and methylated MGMT promoter. Interestingly, 42 of 43 samples (97.7%) with decreased PDL1 expression had the increased EZH1 expression, 31 of 33 samples (93.9%) with decreased CTLA4 expression had the increased RIZ expression, 25 of 26 samples (96.2%) with increased CD137 expression had the increased UTX expression, and 36 of 39 samples (92.3%) with increased CD28 expression had the increased JMJD1a expression, respectively. CONCLUSION The result of presenting study suggest that the regulators of T cell can be considered as independent prognostic factors in glioblastoma patients and the expression of these regulators can be controlled by unique histone 3 lysine methylation enzymes.