Gene expression profiling with oligonucleotide microarrays distinguishes World Health Organization grade of oligodendrogliomas

Oligodendrogliomas are the second most common type of glial neoplasm with d istinct prognostic and therapeutic implications. Although refinements have led to improved clinical stratification, current grading themes are still L imited by subjective histopathological criteria. In this report, we have us ed oligonucleotide array technology to perform expression profiling in morp hologically classic oligodendrogliomas. Expression information from similar to 1100 genes divided tumors into two molecularly distinct groups that cor responded exactly to their previously assigned histological grades. Subsequ ent gene clustering identified a subset of 196 transcripts showing a common , differential expression pattern between tumor grades. A number of these g enes have been associated with the maintenance of cytoarchitecture, cellula r differentiation and maturation, immunogenicity, and chemotherapeutic resi stance, These results demonstrate the utility of gene expression profiling as an objective, ancillary tool for grading oligodendrogliomas and a potent ial approach for classifying diffuse gliomas where histological assessment may be difficult or ambiguous.