Transient Activation of Beta-Catenin Signaling in Adult Mouse Epidermis Induces New Hair Follicles, Continuous Activation Maintains Tumors

The study demonstrated that transient activation of β-catenin signalling in adult mouse epidermis was sufficient to induce new hair follicles, as evidenced by the recruitment of resting hair follicles into the growth cycle and the formation of epithelial outgrowths expressing markers of hair follicle differentiation. This was achieved through the application of 4-hydroxytamoxifen (4OHT) to transgenic mice expressing a modified β-catenin. A single application of 4OHT was as effective as repeated doses. However, continuous activation of β-catenin was necessary to maintain hair follicle tumours, as these benign tumours regressed after the cessation of 4OHT treatment. The findings suggested that adult interfollicular epidermis and sebaceous glands could be reprogrammed, but sustained β-catenin signalling was crucial for maintaining the tumour state.