Gene expression profiling of meningiomas: current status after a decade of microarray-based transcriptomic studies

This article provides a review of the transcriptomic expression profiling studies that have been performed on meningiomas so far. We discuss some future prospects and challenges ahead in the field of gene expression profiling. We performed a systematic search in the PubMed and EMBASE databases in May 2010 using the following search terms alone or in combination: meningioma, microarray analysis, oligonucleotide array sequence analysis, or gene expression profiling. Only original research articles in English that had used RNA hybridized to high-resolution microarray chips to generate gene expression profiles were included. We identified 13 articles matching the inclusion criteria. All studies had been performed during the last decade. The main results of the studies can be grouped in three categories: (1) several groups have identified meningioma-specific genes and genes associated with the three WHO grades, and the main histological subtypes of grade I meningiomas; (2) one publication has shown that the general transcription profile of samples of all WHO grades differs in vivo and in vitro; (3) one report provides evidence that microarray technology can be used in an automated fashion to classify tumors. Due to lack of consensus on how microarray data are presented, possible general trends found across the studies are difficult to extract. This could obstruct the discovery of important genes and pathways universally involved in meningioma biology.