Serial transcriptome analysis and cross-species integration identifies centromere-associated protein E as a novel...

Cancer genomic studies that rely on analysis of biopsies from primary tumors may not fully identify the molecular events associated with tumor progression. We hypothesized that characterizing the transcriptome during tumor progression in the TH-MYCN transgenic model would identify oncogenic drivers that would be targetable therapeutically. We quantified expression of 32,381 murine genes in nine hyperplastic ganglia harvested at three time points and four tumor cohorts of progressively larger size in mice homozygous for the TH-MYCN transgene. We found 93 genes that showed a linearly increasing or decreasing pattern of expression from the preneoplastic ganglia to end stage tumors. Cross-species integration identified 24 genes that were highly expressed in human MYCN-amplified neuroblastomas. The genes prioritized were not exclusively driven by increasing Myc transactivation or proliferative rate. We prioritized three targets [centromere-associated protein E (Cenpe), Gpr49, and inosine monophosphate dehydrogenase type II] with previously determined roles in cancer. Using siRNA knockdown in human neuroblastoma cell lines, we further prioritized CENPE due to inhibition of cellular proliferation. Targeting CENPE with the small molecular inhibitor GSK923295 showed inhibition of in vitro proliferation of 19 neuroblastoma cell lines (median IC(50), 41 nmol/L; range, 27-266 nmol/L) and delayed tumor growth in three xenograft models (P values ranged from P < 0.0001 to P = 0.018). We provide preclinical validation that serial transcriptome analysis of a transgenic mouse model followed by cross-species integration is a useful method to identify therapeutic targets and identify CENPE as a novel therapeutic candidate in neuroblastoma.