[AP-HM tumour tissue bank: molecular signature of gliomas]

The AP-HM tissue bank is the largest one in France regarding some collections, including brain tumors. This collection was used to better characterize some gliomas. In particular because some benign gliomas such as pilocytic astrocytomas (WHO grade I) can be misclassified as malignant ones such as glioblastomas (grade IV) the first aim of our study was to find accurate diagnostic markers. This was done mainly by suppressive substractive hybridization (SSH). This study also provides a restrictive list of genes selectively involved in angiogenesis and invasion, which were highly expressed in GBM. Results were confirmed by real time quantitative RT-PCR in a large cohort of patients. In addition in order to find accurate markers which can predict GBM overall survival (OS) we selected three cohorts of GBM patients with distinctive OS (short survival6 months, long survival18 months and intermediate). Quantification of a series of markers involved in angiogenesis and invasion was done as well as cDNA array analysis.