Cancer type specific copy number variants are identical over species borders

Abstract

Over the past two decades, we have studied dozens of murine and a few rat-derived tumor cell lines. While these cell lines are commonly used as models for human cancer, their cytogenetic and genetic properties are not fully understood. Therefore, we characterized approximately 40 rodent cancer cell lines using molecular cytogenetics, including multicolor fluorescence in situ hybridization and array-comparative genomic hybridization. We then in silico translated the observed acquired gains and losses of chromosomal regions into the human genome. During these studies, we found that rodent cancer cell lines carried chromosomal imbalances similar to those observed in human cancer cells. In this review, we discuss the cell lines studied, the percentage of gains and losses that agreed with the corresponding human cancer type, and the human cancer subtypes for which each cell line can serve as a suitable model. Additionally, we discuss the fact that polyploidy can only be reliably accessed by cytogenetics and that male cell lines tend to lose their Y chromosome. Overall, the reviewed findings highlight the need for an in-depth cytogenomic characterization before using a cell line in research. Furthermore, the data support the idea that copy number changes are more important than point mutations, at least in advanced tumors, as they are similar across species boundaries.