Genome-scale spatial mapping of the Hodgkin lymphoma microenvironment identifies tumor cell survival factors.

A central challenge in cancer research is to identify the secreted factors that sustain tumor cell survival. This is best exemplified in Hodgkin lymphoma, where malignant cells constitute a minor fraction of the tumor and rely on signals from the microenvironment for survival. Using genome-wide transcriptional profiling with spatial and single-cell resolution, we show that the neighborhood around malignant cells forms a distinct niche of 31 non-malignant cell types, enriched in helper T cells and myeloid cells, but depleted of plasma cells. Moreover, our spatial analysis nominates IL13 as a candidate survival factor. Recombinant IL13 augments malignant cell growth in vitro, and genome-wide loss-of-function screens across >1000 human cancer cell lines identify IL4R and IL13RA1, heterodimeric components of the IL13 receptor, as uniquely essential in Hodgkin lymphoma. Importantly, blocking antibodies phenocopy genetic inactivation. Our findings provide a biological rationale for testing IL13-directed therapies, which are already FDA-approved, in Hodgkin lymphoma.