Project description:The airway mucociliary epithelium is consituted of three main cell types : columnar ciliated plus secretory cells and basal cells. Columnar cells are represented by a great majority of ciliated cells. We used Cell sorting by FACSaria to separate basal cells from ciliated and secreting columnar cells. Then, we performed microRNA high throughput sequencing to investigate the specific signature of microRNA of basal and columnar cells.
Project description:The airway mucociliary epithelium is consituted of three main cell types : columnar ciliated plus secretory cells and basal cells. Columnar cells are represented by a great majority of ciliated cells. We used Cell sorting by FACSaria to separate basal cells from ciliated and secreting columnar cells. Then, we performed microRNA high throughput sequencing to investigate the specific signature of microRNA of basal and columnar cells. miRNAs high throughput sequencing profiling of human nasal mucosa: basals cells (B) and columnars (C) cells for 3 donors.
Project description:Columnar cell hyperplasia (CCH) is the first histologically identifiable lesion in the breast with premalignant potential. Altered miRNA expression in the stroma surrounding CCH compared to normal tissue was discovered. The effect of upregulation of one specific miRNA was investigated by gene expression array in human mammary fibroblasts as well as in epithelial CCH cells coculterd with miR-132 oversexpressing human mammary fibroblasts. We used microarrays to detail the effects of miR-132 in human mammary fibroblasts and identified multiple altered genes and gene pathways both in the fibroblasts and in cocultured human mammary epithelial CCH cells.
Project description:Columnar cell hyperplasia (CCH) is the earliest histologically identifiable breast lesion linked to cancer progression and is characterized by increased proliferation, decreased apoptosis and elevated oestrogen receptor a expression. The mechanisms underlying the initiation of these lesions have not been clarified but might involve early and fundamental changes in cancer progression. MiRNAs are key regulators of several biological processes, acting by influencing the posttranscriptional regulation of numerous targets, thus making miRNAs potential candidates in cancer initiation. Here we have defined novel epithelial as well as stromal miRNA signatures from columnar cell hyperplasia lesions compared to normal terminal duct lobular units by using microdissection and miRNA microarrays. MiR-27a, miR-92a and let-7c were among the identified downregulated epithelial miRNAs and their functions were delineated in unique CCH derived cells suggesting pro-apoptotic and anti-proliferative properties for the selected miRNAs and that downregulation of let-7c in CCH cells potentially increased proliferation via Myb. MiR-132 was upregulated in the stroma surrounding CCH compared to stoma surrounding TDLUs, and overexpression of miR-132 in immortalized fibroblasts and in fibroblasts co-cultured with epithelial CCH cells caused substantial expression changes. Global miRNA expression was also examined both epithelial and stroma of one patient displaying TDLU, CCH and additional invasive breast cancer. The miRNA signatures identified in CCH indicate concordant early changes in the epithelial and stromal compartment of CCH and could represent early key alterations in breast cancer progression that potentially could be targeted in novel prevention or treatment schedules.
Project description:In the precursor pathology for oesophageal adenocarcinoma, Barrett’s oesophagus (BO), the adult stratified squamous epithelium is replaced by a simple columnar phenotype. This has been considered metaplasia; the inappropriate conversion from one adult cell-type to another. In fact, BO could be a reversal of mammalian embryogenesis when the early foregut is first lined by simple columnar epithelium. Exploring this hypothesis has been hampered by inadequate molecular details of human oesophageal development. Here, we adopted single cell transcriptomic and epigenomic approaches to discover and decode the cell types that constitute the initial primitive columnar, transitory and subsequently stratified lower oesophageal epithelium. Each stage is comprised of several previously undefined epithelial sub-populations. HNF4A, a major driver of the Barrett’s phenotype, is a prominent transcriptional regulator in the early foregut columnar cells, but not in the later ciliated or stratified cells, and is central to gene regulatory programmes known to be reactivated in BO. Moreover, GWAS susceptibility SNPs for BO mapped to putative regulatory regions in fetal epithelial cells, which are inaccessible in the corresponding adult epithelial cells. Collectively, these data argue that the path to BO involves de-differentiation to a primitive fetal-like state.
Project description:In the precursor pathology for oesophageal adenocarcinoma, Barrett’s oesophagus (BO), the adult stratified squamous epithelium is replaced by a simple columnar phenotype. This has been considered metaplasia; the inappropriate conversion from one adult cell-type to another. In fact, BO could be a reversal of mammalian embryogenesis when the early foregut is first lined by simple columnar epithelium. Exploring this hypothesis has been hampered by inadequate molecular details of human oesophageal development. Here, we adopted single cell transcriptomic and epigenomic approaches to discover and decode the cell types that constitute the initial primitive columnar, transitory and subsequently stratified lower oesophageal epithelium. Each stage is comprised of several previously undefined epithelial sub-populations. HNF4A, a major driver of the Barrett’s phenotype, is a prominent transcriptional regulator in the early foregut columnar cells, but not in the later ciliated or stratified cells, and is central to gene regulatory programmes known to be reactivated in BO. Moreover, GWAS susceptibility SNPs for BO mapped to putative regulatory regions in fetal epithelial cells, which are inaccessible in the corresponding adult epithelial cells. Collectively, these data argue that the path to BO involves de-differentiation to a primitive fetal-like state.
Project description:In the precursor pathology for oesophageal adenocarcinoma, Barrett’s oesophagus (BO), the adult stratified squamous epithelium is replaced by a simple columnar phenotype. This has been considered metaplasia; the inappropriate conversion from one adult cell-type to another. In fact, BO could be a reversal of mammalian embryogenesis when the early foregut is first lined by simple columnar epithelium. Exploring this hypothesis has been hampered by inadequate molecular details of human oesophageal development. Here, we adopted single cell transcriptomic and epigenomic approaches to discover and decode the cell types that constitute the initial primitive columnar, transitory and subsequently stratified lower oesophageal epithelium. Each stage is comprised of several previously undefined epithelial sub-populations. HNF4A, a major driver of the Barrett’s phenotype, is a prominent transcriptional regulator in the early foregut columnar cells, but not in the later ciliated or stratified cells, and is central to gene regulatory programmes known to be reactivated in BO. Moreover, GWAS susceptibility SNPs for BO mapped to putative regulatory regions in fetal epithelial cells, which are inaccessible in the corresponding adult epithelial cells. Collectively, these data argue that the path to BO involves de-differentiation to a primitive fetal-like state.
Project description:The small intestinal epithelium is the most rapidly self-renewing tissue of mammals. Proliferative cells are confined to crypts, while differentiated cell types predominantly occupy the villi. We recently demonstrated the existence of a long-lived pool of cycling stem cells defined by Lgr5 expression and intermingled with post-mitotic Paneth cells at crypt bottoms. We have now determined a gene signature for these so called Crypt Base Columnar (CBC) cells. One of the genes within this stem cell signature is the Wnt target Ascl2. Transgenic expression of the Ascl2 transcription factor throughout the intestinal epithelium induces crypt hyperplasia and de novo crypt formation on villi. Induced deletion of the Ascl2 gene in adult small intestine leads to disappearance of the CBC stem cells within days. The combined results from these gain- and loss-of-function experiments imply that Ascl2 controls intestinal stem cell fate. Keywords: expression profiling
Project description:Enlargement of normal terminal duct lobular units (TDLUs) by hyperplastic columnar epithelial cells is one of the most common abnormalities of growth in the adult female human breast. These hyperplastic enlarged lobular units (HELUs) are important clinically as the earliest histologically identifiable potential precursor of breast cancer. The causes of the hyperplasia are unknown but may include estrogen-simulated growth mediated by estrogen receptor alpha, which is highly elevated in HELUs and may be fundamental to their development. This study used DNA microarray technology and RNA from microdissected pure epithelial cells to learn more about changes in gene expression and molecular pathways associated with the development of HELUs from TDLUs Keywords: Identification of early cancer precursors