Expression data from p63 siRNA in squamous cell lines
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ABSTRACT: p63, a homologue of the tumor suppressor p53, is critical for the development and maintenance of squamous epithelia. p63 is specifically expressed in the basal layers of stratified epithelial tissues, and is considered to be a specific marker for cells of this type. The role of p63 in tumorigenesis remains poorly defined. Numerous studies have highlighted the oncogenic potential of the predominant p63 isoform, ΔNp63α; however, data suggests that other p63 proteins can act as tumor suppressors or alter the metastatic potential of tumors. ΔNp63α can act as a transcriptional repressor, but the link between the transcriptional functions of p63 and its biological role is still unclear. In this study, we used a loss-of-function approach to investigate the transcriptional programs controlled by p63. Keywords: cell line panel
Project description:p63, a homologue of the tumor suppressor p53, is critical for the development and maintenance of squamous epithelia. p63 is specifically expressed in the basal layers of stratified epithelial tissues and is considered a specific marker for cells of this type. The role of p63 in tumorigenesis remains poorly defined. Numerous studies have highlighted the oncogenic potential of the predominant p63 isoform DeltaNp63alpha; however, data suggest that other p63 proteins can act as tumor suppressors or alter the metastatic potential of tumors. DeltaNp63alpha can act as a transcriptional repressor, but the link between the transcriptional functions of p63 and its biological role is still unclear. In this study, we used a loss-of-function approach to investigate the transcriptional programs controlled by p63. Disruption of p63 in squamous cell lines resulted in down-regulation of transcripts specifically expressed in squamous tissues and a significant alteration of keratinocyte differentiation. Interestingly, we found that disruption of p63 led to up-regulation of markers of nonepithelial tissues (mesenchyme and neural tissue) in both primary and immortalized squamous cells. Many of these up-regulated genes are associated with increased capacity for invasion and metastasis in tumors. Furthermore, loss of p63 expression was accompanied by a shift toward mesenchymal morphology and an increase in motility in primary keratinocytes and squamous cell lines. We conclude that loss of endogenous p63 expression results in up-regulation of genes associated with invasion and metastasis, and predisposes to a loss of epithelial and acquisition of mesenchymal characteristics. These findings have implications for the role of p63 in both development and tumorigenesis.
Project description:Transcription factor p63 is a key regulator of stratified epithelia. In humans mutations in p63 are associated with developmental disorders that manifest defects in stratified epithelia including the epidermis. We established an epidermal commitment model using human pluripotent stem cells (PSCs) and characterized differentiation defects of PSCs carrying p63 mutations. Transcriptome analyses revealed distinct phases of epidermal commitment, multipotent simple epithelial, basal stratified epithelial and mature epidermal fates. Differentiation defects of p63 mutant PSCs occurred during the specification switch from the simple epithelium to the basal stratified epithelial fate. Single-cell transcriptome and pseudotime analyses identified enhanced mesodermal signatures associated with the deviated commitment route of p63 mutant PSCs. Repressing mesodermal differentiation improved epidermal commitment of PSCs. Our study demonstrate that p63 is required for specification of stratified epithelia but not sufficient for epidermal maturation. It provides insights into disease mechanisms underlying defects of stratified epithelia caused by p63 mutations.
Project description:p63 is essential for the self-renewal of stem cells of all stratified epithelial tissues, including mammary and prostate glands as well as all squamous epithelia. In p63 null embryos, stratified epithelial tissues are lost or eroded several days after stratification due to the loss of regenerative cell populations. Here we show that p63 null embryos rapidly develop intestine-like metaplasia with gene expression profiles similar to Barrett’s metaplasia in a proximal stomach region. Also, we found that deletion of p63 cells in bladder leads to an expansion of columnar epithelial cells along the basement membrane and their rapid transition to a metaplastic phenotype similar to Barrett’s esophagus. It is likely that bladder carcinogens recapitulate this entire metaplastic transition.
Project description:p63 is critical for epithelial development yet little is known about the transcriptional programmes it regulates. The p63 transactivating (TA) isoforms contain an amino-terminal exon that encodes a p53-like transactivation domain, whereas ΔN-isoforms lack this domain but contain the common DNA binding domain (DBD), suggesting that TAp63 and ΔNp63 isoforms may have opposing functions. By characterising transcriptional changes and cellular effects following modulation of p63 expression, we have defined a vital role for p63 in cellular adhesion. Knockdown of p63 expression caused downregulation of cell adhesion-associated genes, cell detachment and anoikis in mammary epithelial cells and keratinocytes. Conversely, overexpression of the TAp63γ or ΔNp63α isoforms of p63 upregulated cell adhesion molecules, increased cellular adhesion and conferred resistance to anoikis.
Project description:While cell fate determination and maintenance are important in establishing and preserving tissue identity and function during development, aberrant cell fate transition leads to cancer cell heterogeneity and resistance to treatment. Here, we report an unexpected role for the transcription factor p63 (Trp63/TP63) in the fate choice of squamous versus neuroendocrine lineage in esophageal development and malignancy. Deletion of p63 results in extensive neuroendocrine differentiation in the developing mouse esophagus and esophageal progenitors derived from human embryonic stem cells. In human esophageal neuroendocrine carcinoma (eNEC) cells, p63 is transcriptionally silenced by EZH2-mediated H3K27 trimethylation (H3K27me3). Upregulation of the major p63 isoform ΔNp63α, through either ectopic expression or EZH2 inhibition, promotes squamous transdifferentiation of eNEC cells. Together these findings uncover p63 as a rheostat in coordinating the transition between squamous and neuroendocrine cell fates during esophageal development and tumor progression.
Project description:While cell fate determination and maintenance are important in establishing and preserving tissue identity and function during development, aberrant cell fate transition leads to cancer cell heterogeneity and resistance to treatment. Here, we report an unexpected role for the transcription factor p63 (Trp63/TP63) in the fate choice of squamous versus neuroendocrine lineage in esophageal development and malignancy. Deletion of p63 results in extensive neuroendocrine differentiation in the developing mouse esophagus and esophageal progenitors derived from human embryonic stem cells. In human esophageal neuroendocrine carcinoma (eNEC) cells, p63 is transcriptionally silenced by EZH2-mediated H3K27 trimethylation (H3K27me3). Upregulation of the major p63 isoform ΔNp63α, through either ectopic expression or EZH2 inhibition, promotes squamous transdifferentiation of eNEC cells. Together these findings uncover p63 as a rheostat in coordinating the transition between squamous and neuroendocrine cell fates during esophageal development and tumor progression.
Project description:While cell fate determination and maintenance are important in establishing and preserving tissue identity and function during development, aberrant cell fate transition leads to cancer cell heterogeneity and resistance to treatment. Here, we report an unexpected role for the transcription factor p63 (Trp63/TP63) in the fate choice of squamous versus neuroendocrine lineage in esophageal development and malignancy. Deletion of p63 results in extensive neuroendocrine differentiation in the developing mouse esophagus and esophageal progenitors derived from human embryonic stem cells. In human esophageal neuroendocrine carcinoma (eNEC) cells, p63 is transcriptionally silenced by EZH2-mediated H3K27 trimethylation (H3K27me3). Upregulation of the major p63 isoform ΔNp63α, through either ectopic expression or EZH2 inhibition, promotes squamous transdifferentiation of eNEC cells. Together these findings uncover p63 as a rheostat in coordinating the transition between squamous and neuroendocrine cell fates during esophageal development and tumor progression.
Project description:While cell fate determination and maintenance are important in establishing and preserving tissue identity and function during development, aberrant cell fate transition leads to cancer cell heterogeneity and resistance to treatment. Here, we report an unexpected role for the transcription factor p63 (Trp63/TP63) in the fate choice of squamous versus neuroendocrine lineage in esophageal development and malignancy. Deletion of p63 results in extensive neuroendocrine differentiation in the developing mouse esophagus and esophageal progenitors derived from human embryonic stem cells. In human esophageal neuroendocrine carcinoma (eNEC) cells, p63 is transcriptionally silenced by EZH2-mediated H3K27 trimethylation (H3K27me3). Upregulation of the major p63 isoform ΔNp63α, through either ectopic expression or EZH2 inhibition, promotes squamous transdifferentiation of eNEC cells. Together these findings uncover p63 as a rheostat in coordinating the transition between squamous and neuroendocrine cell fates during esophageal development and tumor progression.
Project description:While cell fate determination and maintenance are important in establishing and preserving tissue identity and function during development, aberrant cell fate transition leads to cancer cell heterogeneity and resistance to treatment. Here, we report an unexpected role for the transcription factor p63 (Trp63/TP63) in the fate choice of squamous versus neuroendocrine lineage in esophageal development and malignancy. Deletion of p63 results in extensive neuroendocrine differentiation in the developing mouse esophagus and esophageal progenitors derived from human embryonic stem cells. In human esophageal neuroendocrine carcinoma (eNEC) cells, p63 is transcriptionally silenced by EZH2-mediated H3K27 trimethylation (H3K27me3). Upregulation of the major p63 isoform ΔNp63α, through either ectopic expression or EZH2 inhibition, promotes squamous transdifferentiation of eNEC cells. Together these findings uncover p63 as a rheostat in coordinating the transition between squamous and neuroendocrine cell fates during esophageal development and tumor progression.
Project description:While cell fate determination and maintenance are important in establishing and preserving tissue identity and function during development, aberrant cell fate transition leads to cancer cell heterogeneity and resistance to treatment. Here, we report an unexpected role for the transcription factor p63 (Trp63/TP63) in the fate choice of squamous versus neuroendocrine lineage in esophageal development and malignancy. Deletion of p63 results in extensive neuroendocrine differentiation in the developing mouse esophagus and esophageal progenitors derived from human embryonic stem cells. In human esophageal neuroendocrine carcinoma (eNEC) cells, p63 is transcriptionally silenced by EZH2-mediated H3K27 trimethylation (H3K27me3). Upregulation of the major p63 isoform ΔNp63α, through either ectopic expression or EZH2 inhibition, promotes squamous transdifferentiation of eNEC cells. Together these findings uncover p63 as a rheostat in coordinating the transition between squamous and neuroendocrine cell fates during esophageal development and tumor progression.