Comparable genomic copy number aberrations differ across astrocytoma malignancy grades

Abstract

Malignancy grades of astrocytomas were analyzed for copy number aberrations by aCGH. Altogether 1438 CNA were found of which losses prevailed. We searched for regions that are more likely to drive cancer pathogenesis with Bioconductor package and Genomic Identification of Significant Targets in Cancer. On our total sample significant deletions affected 14 chromosomal regions, out of which deletions at 17p13.2, 9p21.3, 13q12.11, 22q12.3 remained significant even at 0.05 q-value. When divided to malignancy groups, the regions identified as significantly deleted in high grades were: 9p21.3; 17p13.2; 10q24.2; 14q21.3; 1p36.11 and 13q12.11, while amplified were: 3q28; 12q13.3 and 21q22.3. Low grades comprised significant deletions at 3p14.3; 11p15.4; 15q15.1; 16q22.1; 20q11.22 and 22q12.3 indicating their involvement in early stages of tumorigenesis. Significantly enriched pathways brought by DAVID software were PI3K-Akt, Cytokine-cytokine receptor, NODlike receptor, Jak-STAT, RIG-II-like receptor and Toll-like receptor pathways. HPV and herpex simplex infection and inflammation pathways were also represented. Present study brings new data to astrocytoma research amplifying the wide spectrum of changes which could help us identify the regions critical for tumorigenesis.