Inactivation of the Vitamin D Receptor Enhances Susceptibility of Murine Skin to UV-Induced Tumorigenesis

The study concluded that inactivation of the Vitamin D Receptor (VDR) in mice increased their susceptibility to UV-induced skin tumorigenesis. VDR−/− mice developed skin tumors more rapidly and frequently than wildtype controls, showing compromised DNA repair, defective UV-induced growth arrest and apoptosis, and reduced epidermal thickening in response to UV exposure. These findings highlighted the critical protective role of VDR in preventing UV-induced skin damage and tumor formation, independent of its ligand, 1,25(OH)2D3. The study involved various groups of mice with sample sizes ranging from 6 to 23 per group.