Arm-specific multicolor fluorescence in situ hybridization reveals widespread chromosomal instability in glioma cell lines

An investigation of numerical and structural chromosome aberrations using chromosome arm-specific multicolor fluorescence in situ hybridization (armFISH) revealed considerable genetic heterogeneity among and within 11 glioma cell lines. Despite the substantial variation in numerical chromosome alterations among the cell lines, several distinct and glioma growth-associated losses or gains were frequently observed, that is, losses of chromosomes 10, 13, and 22 and gain of chromosome 7 in particular. Structural aberrations frequently affected chromosomes 1, 4, 7, 16, and 19; however, no single structural chromosome aberration common to all or even several glioma cell lines could be found. Structural alterations were often multiform, and a large variety of unstable chromosome structures were detected. Two of the cell lines also harbored small marker chromosomes containing mainly heterochromatin and chromosomal insertions within hetero-chromatic regions. Altogether, the armFISH provides a versatile tool for the identification of chromosomal aberrations as well as their formation patterns in tumors with a complex genome at the level of chromosome arms.