Functional Characterisation of the ATOH1 Molecular Subtype Indicates a Pro-Metastatic Role in Small Cell Lung Cancer

Abstract

ABSTRACTMolecular subtypes of Small Cell Lung Cancer (SCLC) have been described based on differential expression of transcription factors (TFs)ASCL1, NEUROD1,POU2F3and immune-related genes. We previously reported an additional subtype based on expression of the neurogenic TFATOH1within our SCLC Circulating tumour cell- Derived eXplant (CDX) model biobank. Here we show that ATOH1 protein was detected in 7/81 preclinical models and 16/102 clinical samples of SCLC. In CDX models, ATOH1 directly regulated neurogenesis and differentiation programs consistent with roles in normal tissues. Inex vivocultures of ATOH1-positive CDX, ATOH1 was required for cell survival.In vivo, ATOH1 depletion slowed tumour growth and suppressed liver metastasis. Our data validate ATOH1 as abona fideoncogenic driver of SCLC with tumour cell survival and pro-metastatic functions. Further investigation to explore ATOH1 driven vulnerabilities for targeted treatment with predictive biomarkers is warranted.