The skin is maintained by self-renewal, proliferation, and differentiation of tissue-specific stem cells. We have shown previously that the transcription factor p63 plays an essential role in these processes. Expression of p63 serves as a biomarker for the enrichment of epithelial stem cells when it is appropriately monitored. We have found recently that a small molecule compound RepSox stabilizes p63 proteins, allowing us to make the following two challenging tasks possible. First, autologous skin grafts in human have been prepared as epidermal sheets cultivated on top of murine-derived 3T3-J2 feeder cells since 1970. 3T3-J2 cells are indispensable for skin epidermal stem cells to grow while minimizing their spontaneous differentiation in Green method. However, the use of mouse feeder cells has been the debate for decades. We found that the use of RepSox can replace 3T3-J2 cells with human feeder cells such as dermal fibroblasts and adipocyte-derived mesenchyme. Second, despite its importance in basic research of tissue regeneration, it is difficult to grow stem cells of mouse epithelia as they rapidly differentiate and senesce. However, we found that the use of RepSox enables expansion of a variety of primary stem cells of mouse epithelia longterm while avoiding tumorigenesis. We will discuss our ongoing study of “RepSox protocol” at this Conference IDC 2023.
Audience Take Away Points :
• The transcription factor p63 plays an essential role in renewal and differentiation of epithelial.
• RepSox protocol can replace mouse 3T3-J2 cells with human feeder cells.
• RepSox protocol enables stem cells of mouse epithelial to expand long term.