Loss of Sox10 prevents tumor initiation in vivo and induces luminal-to-basal reprogramming in Neu+ tumor cells

Here, we identify SOX10 as a key regulator of tumor-initiating activity in Neu-driven mammary cancers. Genetic ablation of Sox10 in the luminal compartment of MMTV-Neu (NIC) mice resulted in delayed but normal mammary gland development.

Sox10 deletion conferred a dose-dependent delay in tumor onset, with a complete loss of tumor initiation in Sox10-deficient luminal cells. CRISPR/Cas9-mediated Sox10 inactivation in Neu-transformed tumor cells led to reduced 3D invasion and diminished self-renewal in mammosphere assays. Established Sox10-null cell lines exhibited markedly impaired growth in orthotopic transplant models and failed to colonize lung tissue following tail vein injection, suggesting a loss of tumor-initiating capacity.