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

Abstract

Purpose: The 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 methods: We 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.

Results: Among 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.

Conclusions: Our observations demonstrated that impaired autophagy may be associated with BRAF V600E mutation. However, large sample studies with long-term follow-up were required.

Keywords: Autophagy-related protein; BRAF V600E; Epilepsy; Glioneuronal tumors.