Comprehensive characterization of RB1 mutant and MYCN amplified retinoblastoma cell lines

In retinoblastoma research tumor-derived cell lines remain an important model to investigate tumorigenesis and new therapy options, due to limited tumor material and lack of adequate animal models. A panel of 10 retinoblastoma cell lines was characterized with respect to mutation, methylation and expression of RB1 and MYCN. These established retinoblastoma cell lines represent the most frequent types of RB1 inactivation and together with the MYCN amplification status, three classes can be distinguished: RB1^mut/MYCN^nonA, RB1^mut/MYCN^A and RB1^wt/MYCN^A. MYCN amplification was identified in five cell lines, whereby two of them, RB522 and RB3823, harbor no aberration in RB1. Targeted sequencing of 160 genes often mutated in cancer identified only few variants in tumor-associated genes other than in RB1. None of these variants was recurrent. mRNA expression analyses of retinal markers, cell cycle regulators and members of the TP53 signaling pathway revealed a high variability between cell lines but no class-specific differences. The here presented thorough validation of retinoblastoma cell lines, including microsatellite analysis for cell line authentication, provides the basis for further in vitro studies on retinoblastoma.