Cell-Type-Specific Chromatin States Differentially Prime Squamous Cell Carcinoma Tumor-Initiating Cells for Epithelial to Mesenchymal Transition

The study from February 2017 investigated the role of cell-type-specific chromatin states in priming squamous cell carcinoma (SCC) tumor-initiating cells for epithelial to mesenchymal transition (EMT), a process associated with metastasis, stemness, and resistance to therapy. The researchers found that SCCs originating from the interfollicular epidermis (IFE) typically remain well differentiated, whereas SCCs derived from hair follicle (HF) stem cells often undergo EMT, are more efficient at forming secondary tumors, and have a higher metastatic potential. Through transcriptional and epigenomic profiling, it was discovered that IFE and HF tumor-initiating cells have distinct chromatin landscapes and gene regulatory networks related to tumorigenesis and EMT. These networks are associated with the accessibility of binding sites for key epithelial and EMT transcription factors, suggesting that the chromatin state and transcriptional priming are crucial in determining tumor behavior and the likelihood of undergoing EMT.