[Detection of chromosome 17 aneuplody and TP53 gene deletion in a broad variety of solid tumors by dual-color fluorescence in situ hybridization (FISH)].

INTRODUCTION: TP53 is a tumor suppressor gene located on chromosome 17p13.1. This gene is essential for the control of cell cycle and has been found altered in about 50% of all tumor types.
OBJECTIVE: The presence of aneuploidy of chromosome 17 and TP53 gene deletion at 17p13.1 locus was determined in primary solid tumors using the dual-color FISH (fluorescence in situ hybridization).
MATERIALS AND METHODS: Thirty-eight samples consisted of several types of primary solid tumors. All samples were mechanically and enzymatically disaggregated with 0.2% collagenase prior to obtaining interphase nuclei. The dual-color FISH was performed using direct fluorescent labeling probes for the chromosome 17 centromere (green signal) and for the TP53 gene locus-specific (orange signal).
RESULTS: Characteristic aneuploidy on chromosome 17 was found in 63% (24/38) of the samples. Monosomy occurred most frequently (75%, 18/24), followed by trisomy (17%, 4/24); nullisomy and tetrasomy were less frequent. TP53 gene deletion was found in 89.5% (34/38) of cases. Only four tumors were normal for copy number of chromosome 17 and TP53 gene. The histopathologic study showed that most of the samples were malignant tumors.
CONCLUSIONS: Aneuploidy of chromosome 17 and deletion at 17p13.1 locus of TP53 gene were genetic alterations found to be very frequent in solid tumors. The dual-color FISH was able to detect both numerical and structural chromosomal abnormalities in interphase nuclei.