Meta-analysis of microarray gene expression studies on intracranial aneurysms

The rupture of intracranial aneurysms (IAs) is one of the most devastating neurological conditions known to date. Although treatment has changed dramatically throughout the last decades, the outcome of patients still has a poor prognosis. Besides environmental factors, genomics seem to be a very important factor in the genesis of this disease. Different approaches to decrypt genomic causes were pursued throughout the last years. Microarray gene expression studies comparing aneurysmal and healthy tissue seem to be one of the most promising approaches. However, large amounts of data created with each study, make a comparison or interpretation of results difficult. We analyzed microarray gene expression studies on IAs (vs. control tissue) and compared lists of genes with altered expression provided by the authors. Additionally functional pathway analysis was performed. We identified five microarray gene expression studies analyzing a total of 60 samples of IA tissue (30 ruptured IA, 30 unruptured IA). A total of 507 genes with altered expression were listed, of which 57 showed differences in more than two studies and seven in more than three studies (BCL2, COL1A2, COL3A1, COL5A2, CXCL12, TIMP4, TNC). The meta-analysis of five microarray gene expression studies on IAs revealed seven genes that are very likely to be involved in the genesis of IAs. Further analysis of these genes might provide valuable information on mechanisms causing this disease.

▶Analysis of genome-wide microarray gene expression studies on intracranial aneurysms was performed. ▶Gene expression studies of 60 intracranial aneurysms were compared. ▶In all, 507 genes were described to have altered expression levels. ▶Seven genes with altered expression in three or more independent studies were found (BCL2, COL1A2, COL3A1, COL5A2, CXCL12, TIMP4, TNC). ▶These genes are likely to be involved in the genesis of intracranial aneurysms.