P21Waf1/Cip1 Is Differentially Expressed in Epidermal Versus Follicular Melanocytes and Melanoma Cells and Is Phenotypically Regulated by UVB-Mediated Apoptosis
TLDR The protein p21 is more abundant in normal skin cells than in melanoma cells and may help protect against melanoma, with UVB light affecting its levels.
The study investigates the differential expression of the cyclin-dependent kinase inhibitor p21 (p21WAF1/Cip1) in normal melanocytes and melanoma cells, highlighting its role in UVB-mediated apoptosis. Using a multiplex approach, the researchers compared apoptosis markers in primary human epidermal and follicular melanocytes (HEM, HFM) with melanoma cell lines (FM55P, FM55M, SK-MEL-23). They found that p21 is significantly more expressed in normal melanocytes, especially in bulb-derived melanocytes (HFM), than in melanoma cells. UVB exposure increased p21 expression in HEM and primary melanoma cells (FM55P), correlating with decreased Bcl2 expression. This suggests that enhancing p21-mediated cell cycle repair processes in pigment cells could be a strategy to prevent melanoma progression.
