scholarly journals Single-keratinocyte transcriptomic analyses identify different clonal types and proliferative potential mediated by FOXM1 in human epidermal stem cells

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Elena Enzo ◽  
Alessia Secone Seconetti ◽  
Mattia Forcato ◽  
Elena Tenedini ◽  
Maria Pia Polito ◽  
...  
Keyword(s):  
Stem Cells ◽  
Skin Diseases ◽  
Clinical Success ◽  
Essential Feature ◽  
Telomerase Activity ◽  
Proliferative Potential ◽  
Epidermal Stem Cells ◽  
Junctional Epidermolysis Bullosa ◽  
Differentiated Cells ◽  
Cell Transcriptome

AbstractAutologous epidermal cultures restore a functional epidermis on burned patients. Transgenic epidermal grafts do so also in genetic skin diseases such as Junctional Epidermolysis Bullosa. Clinical success strictly requires an adequate number of epidermal stem cells, detected as holoclone-forming cells, which can be only partially distinguished from the other clonogenic keratinocytes and cannot be prospectively isolated. Here we report that single-cell transcriptome analysis of primary human epidermal cultures identifies categories of genes clearly distinguishing the different keratinocyte clonal types, which are hierarchically organized along a continuous, mainly linear trajectory showing that stem cells sequentially generate progenitors producing terminally differentiated cells. Holoclone-forming cells display stem cell hallmarks as genes regulating DNA repair, chromosome segregation, spindle organization and telomerase activity. Finally, we identify FOXM1 as a YAP-dependent key regulator of epidermal stem cells. These findings improve criteria for measuring stem cells in epidermal cultures, which is an essential feature of the graft.

STEM-10. UPSTREAM REGULATORS OF THE GLIOMA STEM CELL PHENOTYPE

2021 ◽  
Vol 23 (Supplement_6) ◽  
pp. vi23-vi23
Author(s):  
Alexandra Calinescu ◽  
Zain Sultan ◽  
McKenzie Kauss ◽  
Wajd Al-Holou ◽  
Jason Heth
Keyword(s):  
Stem Cells ◽  
Tumor Grade ◽  
Telomerase Activity ◽  
Primary Brain Tumor ◽  
Tumor Formation ◽  
High Expression ◽  
Cell Phenotype ◽  
Proliferative Potential ◽  
Loss Of Function ◽  
Significant Enrichment

Abstract Glioblastoma (GBM) is the most common and deadly primary brain tumor in adults. Recurrence of the disease is attributed in part to the presence of Glioma Stem Cells (GSC), which are resistant to chemo- and radiotherapy and can initiate tumor formation. Molecularly, GSCs resemble the mesenchymal subtype that is associated with worse prognosis. GSCs share many characteristics with Neural Stem Cells (NSCs) including proliferative potential, migratory capacity, telomerase activity, diverse progeny and similar gene signature, however differ fundamentally from NSCs in their tumor forming ability. RNA-Seq analysis of GSCs and NSCs illustrates significant enrichment in GSCs of transcription factors (TFs) known to be dysregulated in cancer, chief among them being SIX1, a developmental TF with documented roles in progression of multiple cancers. Overexpression of SIX1 in A172 GBM cells enhances proliferation, promotes resistance to radiotherapy and alters expression of a core set of 4 developmental TFs (POU3F2, SALL2, OLIG2 and SOX2) capable to reprogram differentiated GBM cells into GSCs (Suva et al., 2014). Analysis of SIX1 in surgical samples from glioma patients illustrates that high expression of SIX1 correlates with tumor grade, finding corroborated in the TCGA and CGGA data sets. Surprisingly, primary NSCs, after extended time in culture, increase their proliferation rate, acquire a mesenchymal transcriptional signature akin to GSCs, including high expression of SIX1, and form deadly tumors when implanted into the brains of mice. Comparing the epigenetic landscape of transformed and normal NSCs we identify a significant enrichment of accessible chromatin at promoter and enhancer loci in transformed NSCs, including at regulatory regions of SIX1 and of genes that define mesenchymal GBM. These data suggest that SIX1 may represent an upstream regulator of the GSC phenotype and may drive malignant transformation of NSCs. Genetic and epigenetic loss of function analyses are ongoing to test this hypothesis.

beta-catenin signalling modulates proliferative potential of human epidermal keratinocytes independently of intercellular adhesion

Development ◽  
1999 ◽  
Vol 126 (10) ◽  
pp. 2285-2298 ◽  
Author(s):  
A.J. Zhu ◽  
F.M. Watt
Keyword(s):  
Stem Cells ◽  
Intercellular Adhesion ◽  
Dominant Negative ◽  
Full Length ◽  
Epidermal Keratinocytes ◽  
Dominant Negative Mutant ◽  
Proliferative Potential ◽  
Beta Catenin ◽  
Epidermal Stem Cells ◽  
Armadillo Repeats

We found that cultured human keratinocytes with high proliferative potential, the putative epidermal stem cells, expressed a higher level of noncadherin-associated beta-catenin than populations enriched for keratinocytes of lower proliferative potential. To investigate the physiological significance of this, a series of beta-catenin constructs was introduced into keratinocytes via retroviral infection. Full-length beta-catenin and a mutant containing only nine armadillo repeats had little effect on proliferative potential in culture, the full-length protein being rapidly degraded. However, expression of stabilised, N-terminally truncated beta-catenin increased the proportion of putative stem cells to almost 90% of the proliferative population in vitro without inducing malignant transformation, and relieved the differentiation stimulatory effect of overexpressing the E-cadherin cytoplasmic domain. Conversely, beta-catenin lacking armadillo repeats acted as a dominant negative mutant and stimulated exit from the stem cell compartment in culture. The positive and negative effects of the beta-catenin mutants on proliferative potential were independent of effects on cell-cycle kinetics, overt terminal differentiation or intercellular adhesion, and correlated with stimulation or inhibition of transactivation of a TCF/LEF reporter in basal keratinocytes. We conclude that the elevated level of cytoplasmic beta-catenin in those keratinocytes with characteristics of epidermal stem cells contributes to their high proliferative potential.

scholarly journals Long-Term Stability and Safety of Transgenic Cultured Epidermal Stem Cells in Gene Therapy of Junctional Epidermolysis Bullosa

2014 ◽  
Vol 2 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Laura De Rosa ◽  
Sonia Carulli ◽  
Fabienne Cocchiarella ◽  
Daniela Quaglino ◽  
Elena Enzo ◽  
...  
Keyword(s):  
Stem Cells ◽  
Gene Therapy ◽  
Epidermolysis Bullosa ◽  
Epidermal Stem Cells ◽  
Junctional Epidermolysis Bullosa ◽  
Term Stability ◽  
Long Term Stability
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