Spontaneous tumour regression in keratoacanthomas is driven by Wnt/retinoic acid signalling cross-talk

The study from 10 years ago explored the spontaneous regression of keratoacanthomas (KAs), a type of skin tumor, and found that retinoic acid (RA) signaling plays a crucial role in this process by inhibiting Wnt signaling. The researchers discovered that RA signaling precedes the downregulation of Wnt during the early regression phase of KAs. In mouse models, RA treatment led to decreased nuclear β-catenin, increased Wnt inhibitors, and activation of differentiation programs, resulting in tumor regression. The study also demonstrated that RA signaling could induce regression in squamous cell carcinomas (SCCs), which typically do not regress spontaneously. The findings suggest that targeting RA signaling could be a potential strategy for skin cancer treatment. The sample sizes in the experiments varied, with specific counts such as n=5 for control and mutant mice, n=3 for time points in a time course experiment, and n=5 for qRT-PCR analysis after RA treatment, indicating a moderate number of mice were used in the study.