Marina Grachtchouk

TL;DR: An obligatory role for the secreted morphogen Sonic hedgehog (Shh) during hair follicle development is reported, where it is required for normal advancement beyond the hair germ stage of development.

TL;DR: Gli2 is established as a potent oncogene in skin and a pivotal role for this transcription factor in the development of human BCC is suggested, suggesting a specific downstream effector in the Shh pathway leading to cancer development is unknown.

TL;DR: The results suggest that Shh-dependent Gli2 activation plays a critical role in epithelial homeostasis by promoting proliferation through the transcriptional control of cell cycle regulators.

TL;DR: The data reveal that continued Hh signaling is required for proliferation and survival of established BCCs, provide compelling support for the concept that these tumors represent an aberrant form of follicle organogenesis, and uncover potential limitations to treating BCCs using Hh pathway inhibitors.

TL;DR: The data show that the cell of origin, tissue context (quiescent versus growing hair follicles), and level of oncogenic signaling can determine the phenotype of Hh/Gli-driven skin tumors, with high-level signaling required for development of superficial BCC-like tumors from interfollicular epidermis and nodular BCC- like tumors from hair follicle stem cells.