Cell plasticity in neuroblastoma

Two cell identities, noradrenergic and mesenchymal, have been characterized in neuroblastoma cell lines according to their epigenetic landscapes relying on specific circuitries of transcription factors. Yet, their relationship and relative contribution in patient tumors remain poorly defined. Our results now document spontaneous plasticity in several neuroblastoma models between noradrenergic and mesenchymal tumor states and show that this plasticity is reversible and relies on epigenetic reprogramming. We demonstrate that an in vivo microenvironment provides a powerful pressure towards a noradrenergic identity for these models. Interestingly, single-cell RNA-seq analyses of 18 tumor biopsies and 15 PDX models revealed that tumor cells systematically exhibit a noradrenergic identity. Yet, our data highlight a population of noradrenergic tumor cells with mesenchymal features, demonstrating that the plasticity described in cellular models between both identities is relevant in neuroblastoma patients. Our work also emphasizes that both external cues of the environment and intrinsic factors influence plasticity and cell identity in neuroblastoma. Overall design: ChIP-seq data of neuroblastoma cell lines and xenografts (H3K27ac)