Conservation and alteration of chromosome territory arrangements in thyroid carcinoma cell nuclei.

Chromosome territories (CTs) are intranuclear subregions occupied by individual chromosomes in an interphase cell. In this study, we investigated intranuclear CT positionings of chromosomes 10 (CS10), 18 (CS18), and 19 (CS19) in epithelial cells from four normal thyroid tissue (NT), four adenomatous goiters (AGs), six papillary carcinomas (PCs), and two undifferentiated carcinomas (UCs) using the multicolor fluorescence in situ hybridization method. In the NT and AGs, the radial positionings of CS10 and CS18 were detected at the periphery of nuclei in more than 60% and 80% of cells, respectively, whereas the radial positioning of CS19 was in the central region of the nuclei in more than 80% of cells. In the PCs, radial positioning pattern of CS10 and CS18 were similar to that in the NT. The nuclei with centrally located CS19 in PCs were less frequent than those in NT cells (p < 0.01). On the other hand, UCs with cells having DNA amplification demonstrated the locational abnormalities of the CS10, CS18, and CS19 radial positions. These findings indicate that alteration of CT positioning could be related to DNA amplification and, morphologically, may explain the nuclear atypia that accompanies the abnormal chromatin feature.