Autophagy-related protein expression was associated with BRAF V600E mutation in epilepsy associated glioneuronal tumors

Abstract

PurposeThe aim of this study was to explore the expression level of autophagy-related proteins in epileptic patients with glioneuronal tumors (GNTs) and evaluate the association with clinicopathological features. Materials and methodsWe obtained the brain specimens from 33 patients with GNTs, including 22 gangliogliomas (GGs) and 11 dysembryoplastic neuroepithelial tumors (DNTs). The expression of two autophagy-related proteins (LC3B and Beclin-1) was evaluated by immunohistochemistry, and BRAF V600E mutation was examined by DNA sequencing. ResultsAmong 33 epileptic patients with GNTs, the frequency of high expression of LC3B was 36.4% (12/33), and that of Beclin-1 was 39.4% (13/33). High expression of LC3B and Beclin-1 proteins was significantly associated with BRAF V600E mutation in GNTs (P=0.008; P=0.018), and LC3B overexpression was also correlated with temporal location of GNTs (P=0.002). In GGs alone, high expression of LC3B revealed significant correlation with BRAF V600E mutation and temporal location (P=0.020; P=0.015), while Beclin-1 showed no correlation with them (P>0.05). Furthermore, autophagy-related proteins did not show any association with other studied clinicopathological features, such as gender, age at seizure onset, epilepsy duration and postoperative seizure outcome. ConclusionsOur observations demonstrated that impaired autophagy may be associated with BRAF V600E mutation. However, large sample studies with long-term follow-up were required.