A novel tumorigenic human prostate epithelial cell line (M2205): molecular cytogenetic characterization demonstrates C-MYC amplification and jumping translocations

The paucity of cell lines from early-stage prostate cancer tumors has hindered the recognition of genetic and cellular changes that are associated with the acquisition of tumorigenesis. We describe the chromosomal complement of a novel tumorigenic prostate epithelial cell subline, called M2205, that acquired only three new, consistent chromosomal changes (from those present in the SV40T antigen immortalized parental cell line, P69SV40TAg) when it attained tumor-forming potential. The consistent changes, which were fully characterized using GTG-banding, CBG-banding, silver staining, fluorescence in situ hybridization (FISH), comparative genomic hybridization (CGH), and spectral karyotyping (SKY), involved segmental jumping translocations and resulted in gains in the copy number of genes located on the distal long arm of chromosome 8 (8q22 to 8q24.3), including c-myc. Furthermore, the jumping translocations also resulted in ribosomal genes being present in multiple, tandem copies next to the chromatin from 8q. Given the relatively small number of cytogenetic changes present, this subline provides a means for better understanding the cellular changes associated with the acquired chromosomal imbalances. Further studies of this subline could also provide insight as to the mechanism or mechanisms leading to the formation of jumping translocations, as well as potential position effects resulting from the relocation of ribosomal genes next to other cellular genes or oncogenes.