p53 is essential for chemotherapy-induced hair loss

Anticancer drugs stimulate apoptosis in the hair follicles (HF) and cause h air loss, the most common side effect of chemotherapy. In a mouse model for chemotherapy-induced hair loss, we demonstrate that p53 is essential for t his process: in contrast to wild-type mice, p53-deficient mice show neither hair loss nor apoptosis in the HF keratinocytes that maintained active pro liferation after cyclophosphamide treatment. HF in p53 mutants are characte rized by down-regulation of Fas and insulin-like growth factor-binding prot ein 3 and by increased expression of Bcl-2. These observations indicate tha t local pharmacological inhibition of p53 may be useful to prevent chemothe rapy-associated hair loss.