Reprogramming neuroblastoma by diet-enhanced polyamine depletion
Neuroblastoma is a highly lethal childhood tumor derived from differentiation-arrested neural crest cells1,2. Like all cancers, its growth is fueled by metabolites obtained from either circulation or local biosynthesis3,4. Neuroblastomas depend on local polyamine biosynthesis, with the inhibitor difluoromethylornithine showing clinical activity5. Here we show that such inhibition can be augmented by dietary restriction of upstream amino acid substrates, leading to disruption of oncogenic protein translation, tumor differentiation, and profound survival gains in the TH-MYCN mouse model. Specifically, an arginine/proline-free diet decreases the polyamine precursor ornithine and augments tumor polyamine depletion by difluoromethylornithine. This polyamine depletion causes ribosome stalling, unexpectedly specifically at adenosine-ending codons. Such codons are selectively enriched in cell cycle genes and low in neuronal differentiation genes. Thus, impaired translation of these codons, induced by the diet-drug combination, favors a pro-differentiation proteome. These results suggest that the genes of specific cellular programs have evolved hallmark codon usage preferences that enable coherent translational rewiring in response to metabolic stresses, and that this process can be targeted to activate differentiation of pediatric cancers. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=192 SRC="FIGDIR/small/573662v1_ufig1.gif" ALT="Figure 1"> View larger version (64K): org.highwire.dtl.DTLVardef@1fdbaecorg.highwire.dtl.DTLVardef@fb03f4org.highwire.dtl.DTLVardef@1c0afa7org.highwire.dtl.DTLVardef@14c384f_HPS_FORMAT_FIGEXP M_FIG C_FIG Highlights- Extra-tumoral conversion of arginine feeds tumor ornithine via uptake from circulation in MYCN-neuroblastoma. - A proline and arginine free diet enhances pharmacological polyamine depletion via reduced ornithine substrate availability. - Polyamine depletion disrupts oncogenic translation to induce a pro-differentiation proteome causing neuroblast differentiation and prolonged survival in the TH-MYCN mouse model. - Genes of specific cellular programs have evolved codon usage preferences that enable coherent translational rewiring in response to metabolic stress, such as polyamine depletion.