Genomic and Transcriptomic Features of Dermatofibrosarcoma Protuberans: Unusual Chromosomal Origin of the COL1A1-PDGFB Fusion Gene and Synergistic Effects of Amplified Regions in Tumor Development

Publication date: Available online 10 December 2019Source: Cancer GeneticsAuthor(s): Jan Köster, Elsa Arbajian, Björn Viklund, Anders Isaksson, Jakob Hofvander, Felix Haglund, Henrik Bauer, Linda Magnusson, Nils Mandahl, Fredrik MertensAbstractThe dermatofibrosarcoma protuberans family of tumors (DPFT) comprises cutaneous soft tissue neoplasms associated with aberrant PDGFBR signaling, typically through a COL1A1-PDGFB fusion. The aim of the present study was to obtain a better understanding of the chromosomal origin of this fusion and to assess the spectrum of secondary mutations at the chromosome and nucleotide levels. We thus investigated 42 tumor samples from 35 patients using chromosome banding, fluorescence in situ hybridization, single nucleotide polymorphism arrays, and/or massively parallel sequencing (gene panel, whole exome and transcriptome sequencing) methods. We confirmed the age-associated differences in the origin of the COL1A1-PDGFB fusion and could show that it in most cases must arise after DNA synthesis, i.e., in the S or G2 phase of the cell cycle. Whereas there was a non-random pattern of secondary chromosomal rearrangements, single nucleotide variants seem to have little impact on tumor progression. No clear genomic differences between low-grade and high-grade DPFT were found, but the number of chromosomes and chromosomal imbalances as well as the frequency of 9p deletions all tended to be greater among the latter. Gene expression profiling of tumors w...
Source: Cancer Genetics - Category: Cancer & Oncology Source Type: research