Olfactory neuroblastoma mimics molecular subtypes and lineage trajectories of small cell lung cancer [Single nucleus RNA-seq on human ONB tumor]

The olfactory epithelium relies on active neuron regeneration from basal stem cells and is susceptible to olfactory neuroblastoma (ONB), a rare, aggressive tumor of unclear origins. Here, we establish a new, highly-penetrant, genetically-engineered mouse model of ONB with alterations in Rb1/Trp53/Myc that exhibit a NEUROD1+ immature neuronal state. ASCL1 loss leads to emergence of non-neuronal histopathologies, including a POU2F3+ microvillar-like state. We find ONB tumor heterogeneity to recapitulate developmental states of multipotent globose basal cells (GBCs), which our data demonstrate is a cell of origin for ONB. Similar to small cell lung cancer (SCLC), mouse and human ONB exhibit: mutually exclusive ASCL1, NEUROD1, and POU2F3- like states, an immune-cold tumor microenvironment, intratumoral subtype heterogeneity comprising neuronal and non-neuronal lineages, and subtype plasticity—as evidenced by barcode-based lineage tracing and single-cell transcriptomics. Collectively, our findings highlight conserved developmental trajectories between ONB and SCLC subtypes with significant implications for ONB classification and treatment. We harvested one olfactory neuroblastoma tumor specimen from the operating room and flash froze the sample. The flash frozen pellet was dissociated at a later time, and nuclei were isolated using the standard 10X Genomics Nuclear Isolation Kit. Dissociated nuclei were then loaded onto a 10X Chromium controller and subject to 10X Genomics single-cell gene expression library construction (Dual-Index 3' GEX) and downstream Illumina-based sequencing.