Proteomic data in meningiomas: post-proteomic analysis can reveal novel pathophysiological pathways

Meningiomas account for approximately 20% of adult primary intracranial tumours. WHO I meningiomas are the most common and are generally benign, but can progress, recur or transform to WHO II or WHO III grades over many years. A systematic review of multiple independent shotgun proteomic analyses of meningioma was performed to provide insight into underlying disease pathways. Shotgun proteomics has been conducted in seven meningioma related studies but there is considerable variation in aims, methodology, statistical power and the use of control tissue between these studies. Fifteen proteins which are different between WHO I and WHO II meningiomas and nine proteins which are different between WHO II and WHO III meningiomas have been described but without a view of their biological significance. Network analysis of proteins different between WHO I and WHO II meningiomas provided a coherent hypothesis for the involvement of these proteins in meningioma. Western blot analyses of meningioma tissue provided a measure of support for a core component in the network (involving VDAC2, APOA1 and HNF4 alpha) but highlighted intrinsic difficulty of proteomic and biochemical analysis of meningiomas (as a consequence of gross alterations in tissue composition). Systematic review of shotgun proteomics and network analysis provides insight into meningioma pathophysiology despite the many barriers and difficulties that are inherent to this type of study.