Epithelial to mesenchymal transition (EMT) in cancer cells has been associated with metastasis, stemness and resistance to therapy. The reason why some tumors undergo EMT and other not might reflect intrinsic properties of their cell of origin, although this possibility is largely unexplored. By targeting the same oncogenic mutations to discrete skin compartments, we show cell type-specific chromatin and transcriptional states differentially prime tumors to EMT. Squamous cell carcinomas (SCCs) derived from intrafollicular epidermis (IFE) are generally well-differentiated, while hair follicle (HF) stem cell-derived SCCs frequently exhibit EMT, efficiently form secondary tumors, and possess increased metastatic potential. Transcriptional and epigenomic profiling revealed IFE and HF tumor-initiating cells possess distinct chromatin landscapes and gene regulatory networks associated with tumorigenesis and EMT that correlate with accessibility of key epithelial and EMT transcription factor binding sites. These findings highlight the importance of chromatin states and transcriptional priming in dictating tumor phenotypes and EMT.
Cell-Type-Specific Chromatin States Differentially Prime Squamous Cell Carcinoma Tumor-Initiating Cells for Epithelial to Mesenchymal Transition.
Sex, Specimen part, Treatment
View SamplesEpithelial to mesenchymal transition (EMT) in cancer cells has been associated with metastasis, stemness and resistance to therapy. The reason why some tumors undergo EMT and other not might reflect intrinsic properties of their cell of origin, although this possibility is largely unexplored. By targeting the same oncogenic mutations to discrete skin compartments, we show cell type-specific chromatin and transcriptional states differentially prime tumors to EMT. Squamous cell carcinomas (SCCs) derived from intrafollicular epidermis (IFE) are generally well-differentiated, while hair follicle (HF) stem cell-derived SCCs frequently exhibit EMT, efficiently form secondary tumors, and possess increased metastatic potential. Transcriptional and epigenomic profiling revealed IFE and HF tumor-initiating cells possess distinct chromatin landscapes and gene regulatory networks associated with tumorigenesis and EMT that correlate with accessibility of key epithelial and EMT transcription factor binding sites. These findings highlight the importance of chromatin states and transcriptional priming in dictating tumor phenotypes and EMT.
Cell-Type-Specific Chromatin States Differentially Prime Squamous Cell Carcinoma Tumor-Initiating Cells for Epithelial to Mesenchymal Transition.
Treatment
View SamplesCancer stem cells (CSCs) have been reported in various cancers including skin squamous cell carcinoma (SCC). The molecular mechanisms regulating tumour initiation and stemness are still poorly characterized. Here, we found that Sox2, a transcription factor expressed in various types of embryonic and adult stem cells (SCs), was the most upregulated transcription factor in CSCs of squamous skin tumours. Sox2 is absent in normal epidermis and begins to be expressed in the vast majority of mouse and human pre-neoplastic skin tumours and continues to be expressed in a heterogeneous manner in invasive mouse and human SCCs. In contrast to other SCCs, in which Sox2 is frequently genetically amplified, the expression of Sox2 in mouse and human skin SCCs is transcriptionally regulated. Conditional deletion of Sox2 in the mouse epidermis dramatically decreases skin tumour formation following chemical induced carcinogenesis. Using Sox2-GFP knockin mice, we showed that Sox2 expressing cells in invasive SCC are greatly enriched in tumour propagating cells (TPCs) that further increase upon serial transplantations. Lineage ablation of Sox2 expressing cells within primary benign and malignant SCCs leads to tumour regression, consistent with the critical role of Sox2 expressing cells in tumour maintenance. Conditional Sox2 deletion in pre-existing skin papilloma and SCC leads to their regression and decreases their ability to be propagated upon transplantation into immunodeficient mice, supporting the essential role of Sox2 in regulating CSC functions. Transcriptional profiling of Sox2-GFP expressing CSC and upon Sox2 deletion uncovered a gene network regulated by Sox2 in primary tumour cells in vivo. Chromatin immunoprecipitation identified several direct Sox2 target genes controlling tumour stemness, survival, proliferation, adhesion, invasion, and paraneoplastic syndrome. Altogether, our study demonstrates that Sox2, by marking and regulating the functions of skin tumour initiating cells and CSCs, establishes a continuum between tumour initiation and progression in primary skin tumours.
SOX2 controls tumour initiation and cancer stem-cell functions in squamous-cell carcinoma.
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View SamplesCancer stem cells (CSCs) have been reported in various cancers including skin squamous cell carcinoma (SCC). The molecular mechanisms regulating tumour initiation and stemness are still poorly characterized. Here, we found that Sox2, a transcription factor expressed in various types of embryonic and adult stem cells (SCs), was the most upregulated transcription factor in CSCs of squamous skin tumours. Sox2 is absent in normal epidermis and begins to be expressed in the vast majority of mouse and human pre-neoplastic skin tumours and continues to be expressed in a heterogeneous manner in invasive mouse and human SCCs. In contrast to other SCCs, in which Sox2 is frequently genetically amplified, the expression of Sox2 in mouse and human skin SCCs is transcriptionally regulated. Conditional deletion of Sox2 in the mouse epidermis dramatically decreases skin tumour formation following chemical induced carcinogenesis. Using Sox2-GFP knockin mice, we showed that Sox2 expressing cells in invasive SCC are greatly enriched in tumour propagating cells (TPCs) that further increase upon serial transplantations. Lineage ablation of Sox2 expressing cells within primary benign and malignant SCCs leads to tumour regression, consistent with the critical role of Sox2 expressing cells in tumour maintenance. Conditional Sox2 deletion in pre-existing skin papilloma and SCC leads to their regression and decreases their ability to be propagated upon transplantation into immunodeficient mice, supporting the essential role of Sox2 in regulating CSC functions. Transcriptional profiling of Sox2-GFP expressing CSC and upon Sox2 deletion uncovered a gene network regulated by Sox2 in primary tumour cells in vivo. Chromatin immunoprecipitation identified several direct Sox2 target genes controlling tumour stemness, survival, proliferation, adhesion, invasion, and paraneoplastic syndrome. Altogether, our study demonstrates that Sox2, by marking and regulating the functions of skin tumour initiating cells and CSCs, establishes a continuum between tumour initiation and progression in primary skin tumours.
SOX2 controls tumour initiation and cancer stem-cell functions in squamous-cell carcinoma.
Specimen part
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