MOLECULAR ANALYSIS OF GENETIC CHANGES IN EPENDYMOMAS

Ependymomas are glial cell-derived tumors. They are, in contrast to ot her gliomas (astrocytomas, oligodendrogliomas, and oligoastrocytomas), ill-defined with respect to the genes and chromosomal segments import ant in their tumorigenesis. In this study, we extensively screened 17 ependymomas for genetic changes characteristic of other gliomas. Allel ic loss was detected on chromosome arm 22q in three tumors; on chromos ome 10 in two tumors; on chromosome arm 17p in two tumors; and on chro mosome arms 6q, 9p, 13q, and 19q, each in one tumor. No allelic losses were found on chromosome arms 1p and 16q, None of the tumors had EGFR gene amplification. In each case, the chromosomal segment affected by the deletion included the region known to harbor a tumor suppressor g ene important in glioma tumorigenesis. We conclude that ependymomas re semble the other glial neoplasms with respect to type and location of the chromosomal changes involved. Given the relatively infrequent occu rrence of these genetic changes, ependymomas should be considered gene tically as low-grade gliomas. (C) 1995 Wiley-Liss, Inc.