TMOD-31. NOVEL GENETIC CHARACTERIZATION OF MURINE MEDULLOBLASTOMA CELL LINES

Abstract

Abstract Pre-clinical research in medulloblastoma (MB) is conducted either with human-derived cell lines or tumors arising in genetically engineered mice (GEM). Murine MB cell lines are not readily available. To begin in vitro immuno-oncology MB research, we identified murine MB cell lines from research laboratories to determine their fidelity to human cell lines and GEM models. Using PubMed, we identified murine MB cell lines of potential interest. Seven cell lines form two independent laboratories were identified. We characterized the cell lines’ behavior in culture and performed next generation sequencing (NGS) on four of them (two from each group) to determine the extent to which these cell lines resemble both human and GEM MB models. DNA and RNA were extracted from MB cell lines, quality and quantity assessed. Whole-exome sequencing was performed and post-capture libraries sequenced. The cell lines identified were derived from either FVB/N TP53 null mice carrying the N-MYC oncogene (GTML3 and GTML5) or C57Bl6/J TP53 null heterozygous ptch (-/+) mice (MM1 and MM3). GTML cells grow in suspension and form clusters. MM cells are adherent, growing in monolayers. Whole exome sequencing of the 4 lines revealed similarities between both GEM and human MB cell lines, demonstrating 25% of sixteen genes known to be affected in both GEM tumors and human MB cell lines. Furthermore, the four cell Iines shared five deleterious mutations previously not described in MB, suggesting they might play a role in MB tumorigenesis: Pde4d, Whrln, Olr156, RIKEN cDNA D630045J12, and Olfr159. These are the first data to describe these murine MB cell lines and demonstrates 1) they resemble both GEM tumors and human MB cell lines at the genome level, and 2) they offer the potential to identify heretofore unrecognized mechanisms in MB tumorigenesis.