Oncogenic Ras: A double-edged sword for human epidermal stem and transient amplifying cells

Area of Science:

• Dermatology
• Cancer Biology
• Cell Biology

Background:

• Human epidermal clonal evolution, from stem cells (SCs) to transient amplifying (TA)-cells and post-mitotic cells, maintains skin homeostasis.
• Ras GTPases are crucial for skin homeostasis and tumorigenesis, with mutations found in cutaneous squamous cell carcinomas (cSCCs).

Purpose of the Study:

• To investigate the relationship between Ras signaling outcomes and the clonogenic potential of keratinocytes.
• To elucidate the development of tumor-initiating cells (Cancer Stem Cells - CSCs) from normal SCs or TA-cells in the context of Ras signaling.

Main Methods:

• The study discusses the effects of Ras expression on keratinocyte clonogenicity.
• Analysis of Ras signaling pathways in mouse models of cSCC.

Main Results:

• Ras signaling can induce hyperproliferative phenotypes and cSCC development in mouse models.
• The specific cellular origin of Ras-driven transformation influences cSCC development.

Conclusions:

• Ras signaling plays a significant role in skin homeostasis and the development of cSCC.
• Understanding the link between Ras expression and keratinocyte clonogenic potential is key to understanding cSCC pathogenesis and the origin of CSCs.