Genomic Analysis and Gene-based Medicine for Benign Brain Tumors

Abstract

  The aim of this study was to review recent advances in genomic analysis and explore possibilities in genomic medicine for benign brain tumors, particularly craniopharyngioma, meningioma, and schwannoma. Craniopharyngioma includes the adamantinomatous and papillary subtypes. Recent genetic analysis has demonstrated that the two subtypes differ not only in clinicopathological features but also in molecular oncogenesis. Adamantinomatous craniopharyngioma tumors can be distinguished by the frequent mutation of the β-catenin gene (mutations of CTNNB1), whereas the papillary subtype is characterized by the V600E mutation of the BRAF gene activating the MAP kinase pathway (MAPK). A clinical trial currently underway for the papillary subtype is investigating the use of a MAPK inhibitor. Meningiomas have exhibited frequent chromosomal alterations, including mutations at the NF2 locus. Recent studies demonstrated that driver genes such as TRAF7, KLF4, AKT1, and SMO are mutated in 40% of sporadic meningiomas. Umbrella trials for SMO, AKT1, and NF2 mutations are currently being conducted. The novel fusion gene SH3PXD2A-HTRA1, which activates the MAPK pathway, has been associated with sporadic schwannoma. Anti-angiogenic therapy with bevacizumab has been effective for NF2-associated schwannoma. Clinical trials of bevacizumab for NF2-associated schwannoma have also been conducted in Japan.