TPX2 as key downstream target of the eIF4A controlled translational program in MYCN driven neuroblastoma

Current therapies for neuroblastoma, a pediatric tumor arising from immature sympathoblast progenitors of the peripheral sympathetic nervous system, are often ineffective and most survivors suffer from severe long-term therapy related side-effects, underscoring the need for identification of novel drugging strategies with limited toxicity. We performed for the first time an in-depth phenotypic and molecular evaluation of pharmacological eIF4A inhibition in neuroblastoma using the rocaglate CR31B, scrutinizing its mode-of-action through a comprehensive and integrated shotgun proteome profiling and combined ribosome/RNA-seq footprinting approach. Short-term treatment of neuroblastoma cells with CR31B significantly affected viability within the very low nanomolar concentration range. Notably, ribosome footprinting following short-term CR31B exposure (6 hours) revealed amongst others strong enrichment for transcripts encoding proteins involved in N-glycan biosynthesis amongst the downregulated hits, while upregulated targets are enriched for oxidative phosphorylation pathway components. Shotgun proteome profiles during long-term (24h-48h-72h) CR31B exposure revealed a strong enrichment of a FOXM1 driven signature amongst the downregulated hits, a key regulator implicated in cell cycle control and DNA damage response in neuroblastoma. Last, we could show that CR31B significantly reduces tumor growth in vivo without apparent toxicity in a neuroblastoma PDX model. In conclusion, we present CR31B as a potent novel potent therapeutic agent in neuroblastoma.