Abstract

BACKGROUND
The purpose of this study was to determine the genetic abnormalities of chromosomes 9p21, 17p13.1, 3p25 and 3p14.2 in the development and progression of astrocytic tumors.
METHODS
We performed loss of heterozygosity (LOH) analysis in 41 astrocytic tumors, including 20 astrocytomas, 11 anaplastic astrocytomas and 10 glioblastomas, and correlated the results of LOH at different histopathologic grades. LOH was determined by multiplex polymerase chain reaction analysis of the DNA, which was extracted by microdissection.
RESULTS
LOH of 9p21 was found in 55.6% of astrocytomas, 54.6% of anaplastic astrocytomas and 100.0% of glioblastomas. LOH of 17p13.1 was found in 21.4% of astrocytomas, 28.6% of anaplastic astrocytomas, and 66.7% of glioblastomas. LOH of 3p25 was found in 37.5% of astrocytomas, 16.7% of anaplastic astrocytomas, and 14.3% of glioblastomas. LOH of 3p14.2 was found in 16.7% of astrocytomas, 40.0% of anaplastic astrocytomas, and 42.9% of glioblastomas. LOH on chromosome 9p21 and 17p13.1 was closely related with the histopathologic grades.
CONCLUSIONS
These results may suggest that LOH of 9p21, 17p13.1, 3p25 and 3p14.2 involves an early event of astrocytoma development and accumulates during progression. LOH of 3p25 may be involved in the tumorigenesis of astrocytoma. Identification of these LOH may illuminate the stepwise pathogenesis of astrocytic tumors and predict the possibility of malignant transformation.

• Keywords: Astrocytoma;Loss of heterozygosity;9p21;17p13;3p;