Induction of Basal Cell Carcinomas and Trichoepitheliomas in Mice Overexpressing GLI-1

The study demonstrated that mice overexpressing the human Cubitus interruptus homolog GLI-1 in their skin developed tumors similar to human basal cell carcinomas (BCCs) and other hair follicle-derived neoplasias, such as trichoepitheliomas. The research highlighted that the activation of the Sonic hedgehog/Patched signaling pathway, particularly through GLI-1, was crucial for tumor development. Importantly, the tumors exhibited wild-type p53 and Ha ras genes, indicating that GLI-1 overexpression alone was likely sufficient for tumor formation without the need for additional mutations in these genes. This suggested a significant role of GLI-1 in the pathogenesis of BCCs.