Combined inhibition of Aurora-A and ATR kinases results in regression of MYCN-amplified neuroblastoma

Amplification of MYCN is the driving oncogenic change in a subset of high-risk neuroblastomas. The MYCN protein and the Aurora-A kinase form a complex during the S phase that stabilizes MYCN. Here we show that MYCN activates Aurora-A on chromatin, which phosphorylates histone H3 at serine 10 in the S phase, promotes the deposition of histone H3.3 and suppresses R-loop formation. Inhibition of Aurora-A induces transcription–replication conflicts and activates ataxia telangiectasia and Rad3-related (ATR) kinase, which limits double-strand break accumulation upon Aurora-A inhibition. Combined inhibition of Aurora-A and ATR kinases induces rampant tumor-specific apoptosis and tumor regression in mouse models of neuroblastoma, leading to permanent eradication in a subset of mice. The therapeutic efficacy is due to both tumor cell-intrinsic and immune cell-mediated mechanisms. We propose that targeting the ability of Aurora-A to resolve transcription–replication conflicts is an effective therapy for MYCN-driven neuroblastoma.