Amplification of different satellite-DNAs in prostate cancer

Abstract

In various solid tumors and corresponding cell lines, prior research has identified acquired copy number variations (CNVs) encompassing centromeric satellite-DNA sequences. This observation emerged from the application of centromeric probes (satellite-DNA) as controls in molecular cytogenetic investigations and diagnostics, although these accounts were largely anecdotal. In this study, we conducted a systematic screening for satellite-DNA sequence amplification in 31 prostate cancer (PCa) samples, a prevalent malignancy in men characterized by discernible molecular cytogenetic aberrations. Notably, PCa-typical genetic aberrations, such as TMPRSS2-ERG gene rearrangements and PTEN deletion, were identified in 12 and 6 out of the 31 PCa samples, respectively. Overall, PCa exhibited genomic instability marked by chromosomal gain or loss of signals across nearly all tested satellite-DNA regions, with particular emphasis on the Y-chromosome (18/31 cases). Remarkably, 5/12 PCa samples representing more advanced metastatic cancer displayed amplification of one or two satellite DNA stretches each, being detectable as blocks analogous to homogenously staining regions. Notably, these stretches included α-satellite DNA derived from chromosomes 2, 3, 4, 15, and 20, as well as satellite-III DNAs (D1Z1 and DYZ1). These findings align with recent discoveries indicating that α-satellite DNAs are expressed as long-non-coding RNAs in advanced cancer, particularly in the context of PCa.

Keywords: Fluorescence in situ hybridization (FISH); Heterochromatin; Prostate cancer (PCa); Satellite DNA.