SOX2 is a dispensable modulator of NUT carcinoma oncogenesis in mouse
NUT carcinoma (NC) is a highly aggressive malignancy driven by BRD4::NUTM1 and other NUTM1 fusion oncogenes. BRD4::NUTM1 aberrantly activates transcription factors (TFs) linked to basal progenitor identity, producing poorly differentiated squamous phenotypes. Among these TFs, SOX2 has been proposed as a critical oncogenic driver, but its functional requirement in NC has not been tested in vivo. Using a genetically engineered mouse model that faithfully recapitulates human NC, we performed lineage-specific conditional deletion of Sox2 in both squamous and non-squamous tissues. We found that Sox2 is dispensable for NC initiation and progression, with tumors retaining characteristic histology and expression of key drivers including BRD4::NUTM1, MYC, and TP63. Transcriptomic profiling revealed only modest changes in Sox2-deficient tumors, mainly affecting metabolic and biosynthetic pathways, without disrupting core oncogenic programs. These findings challenge the assumption that SOX2 is universally required in NC and suggest that SOX2-targeted therapies may have limited utility, refining the framework for therapeutic prioritization. Summary blurbThis study shows that SOX2 is not required for NUT carcinoma initiation or maintenance in vivo, challenging its assumed oncogenic role and refining therapeutic target prioritization.