Instability of microsatellites in human gliomas.
We have analyzed DNA obtained from 10 glioblastomas multiforme and 6 astrocytomas for microsatellite instability, using 17 different microsatellite loci dispersed over 7 different chromosomes. Six of 16 gliomas showed 1 or more microsatellite alterations in tumor DNA as compared to constitutional DNA. We observed microsatellite instability resulting in allelic shifts in 5 of 10 glioblastomas multiforme but not in any of the astrocytomas. Loss of an allele was observed in 3 glioblastomas multiforme. An imbalance in the intensity of alleles was noticed in 1 astrocytoma and in 1 glioblastoma multiforme. In 1 glioblastoma multiforme, an extra allele was present at two distinct loci. Overall, 5.3% of microsatellite analyses showed an abnormality. We conclude that microsatellite instability is present at a low grade in glioblastomas multiforme but to a lesser extent in astrocytomas. Genomic instability in human gliomas, therefore, should not be regarded as a mechanism for tumor initiation but as an evolution in tumor progression.
Dams
E
E
Department of Medical Genetics, University of Antwerp, UIA, Belgium.
Van de Kelft
E J
EJ
Martin
J J
JJ
Verlooy
J
J
Willems
P J
PJ
D000483:Alleles; D001254:Astrocytoma / Q000235:genetics*; D001932:Brain Neoplasms / Q000235:genetics*; D002872:Chromosome Deletion; D004273:DNA, Neoplasm / Q000032:analysis*; D004276:DNA, Satellite / Q000032:analysis*; D005909:Glioblastoma / Q000235:genetics*; D006801:Humans
D004273:DNA, Neoplasm; D004276:DNA, Satellite