Basal cell carcinomas in mice arise from hair follicle stem cells and multiple epithelial progenitor populations

This study demonstrated that basal cell carcinomas (BCCs) in mice could originate from hair follicle stem cells and various epithelial progenitor populations, influenced by the level and context of Hedgehog (Hh) signaling. By inducing the GLI2 activator (GLI2ΔN), a key mediator of Hh signaling, in different skin compartments, researchers found that nodular BCCs developed from hair follicle stem cells, particularly in the lower bulge and secondary hair germ compartments, while superficial BCCs arose from the epidermis. The study highlighted that the cell of origin, whether in quiescent or growing hair follicles, and the intensity of oncogenic signaling, determined the type of BCC that developed, with high-level signaling necessary for superficial BCC-like tumors and nodular BCC-like tumors.