Author/Authors :
Haylett، نويسنده , , Ann K. and Forbes، نويسنده , , Ethel and MacLennan، نويسنده , , Alex and Truscott، نويسنده , , T.George and Moore، نويسنده , , James V.، نويسنده ,
Abstract :
Gene amplification has been found to be biologically important in cancer. We report a complementary DNA sequence obtained using a subtractive hybridization approach which is frequently and highly amplified in human gliomas. 3945 (87%) glial tumor specimens (of pathologically low and high grade) revealed increases in copy number of this clone from 5- to 25-fold; erb-b amplification was found in 845 (18%). This clone revealed homology to non-continuous mitochondrial DNA positions 1679–1948 and 2017–2057, with the interspersed sequences deleted. A non-mitochondrial genomic addition of 15 bases at the 5′ end of the clone and a 7 base insertion adjacent to position 1948 were also present. Evaluation of the entire mitochondrial genome in a subset of 11 tumors showed maximal amplification between mitochondrial positions 748 and 5882, and a lower degree of amplification elsewhere, with a recurrent deletion of a 1.2 kb EcoRI fragment noted in 511 (46%) tumors. The mitochondrial genome is frequently affected in human gliomas, and warrants further study to determine its role in glial malignancy.
