Epigenetic regulation of cell state by H2AFY governs immunogenicity in high-risk neuroblastoma [CRISPR/Cas9 screen]

Childhood neuroblastoma with MYCN-amplification is classified as high-risk and often relapses after intensive treatment regimen. Immune checkpoint blockade therapy shows limited efficacy in neuroblastoma patients and the cancer intrinsic immune regulatory network is poorly understood. Here, we leveraged genome-wide CRISPR/Cas9 screens in a human co-culture system and identified H2AFY as a resistance gene to nivolumab. Genetic deletion of H2afy in MYCN-driven neuroblastoma cells reverted in vivo resistance to PD-1 blockade by eliciting concurrent activation of the adaptive and innate immunity. Analysis of single-cell RNA sequencing datasets revealed that H2AFY mRNA was enriched in adrenergic cancer cells and was associated with patient survival. Mapping of the epigenetic and translational landscape demonstrated that H2afy deletion promoted cell transition to a malignant mesenchymal-like state. With a multi-omics approach, we uncovered H2AFY-associated genes that were functionally relevant and prognostic in patients. Altogether, our study elucidates the role of H2AFY as an epigenetic gatekeeper for cell state and immunogenicity in high-risk human neuroblastoma. Overall design: We leverage genome-wide CRISPR/Cas9 screen in IMR32 neuroblastoma cells to identify resistance genes to nivolumab treatment, a clinically approved PD-1 blocking antibody.