Cytogenetic evidence that a tumor suppressor gene in the long arm of chromosome 1 contributes to glioma growth

In a patient with a rare subtype of glioma, pleomorphic xanthoastrocytoma, cytogenetic studies revealed that both homologues of chromosome 1 were involved in translocations at the same band 1q42 but with different partner chromosomes. In addition, 5 glioblastomas out of 25 gliomas karyotyped in our laboratory had lost at least one copy of band 1q42 through deletions, unbalanced rearrangements, or chromosome losses. Twenty-one gliomas that had lost at least one copy of chromosome band 1q42 were identified in the literature; all were astrocytic tumors and the majority were glioblastomas. It indicates a covert tumor suppressor gene in the region that is involved in astrocytic gliomas.