Breast Cancer Resistance Protein Identifies Clonogenic Keratinocytes in Human Interfollicular Epidermis

The study identified the breast cancer resistance protein (ABCG2) as a marker for clonogenic keratinocyte progenitor cells in human interfollicular epidermis. ABCG2 was expressed in about 2-3% of keratinocytes and these ABCG2-positive cells demonstrated higher colony-forming efficiency and long-term proliferation capacity compared to ABCG2-negative cells. The research involved human skin samples from 6 neonatal foreskin donors and 4 adult scalp skin donors. ABCG2-positive keratinocytes showed high expression of stem cell markers and low expression of differentiation markers, indicating their potential as progenitor cells. The study suggested that ABCG2 could be used to enrich keratinocyte stem cells, which could have implications for cell and gene therapy applications, particularly in wound healing and skin replacement therapies.