Chromatin and transcription factor profiling in rare stem cell populations using CUT&Tag

Long-lived cancer stem cells (CSCs) with indefinite proliferative potential have been identified in multiple epithelial cancer types. These cells are likely derived from transformed adult stem cells and are thought to share many characteristics with their parental population, including a quiescent slow-cycling phenotype. Various label-retaining techniques have been used to identify normal slow cycling adult stem cell populations and offer a unique methodology to functionally identify and isolate cancer stem cells. The quiescent nature of CSCs represents an inherent mechanism that at least partially explains chemotherapy resistance and recurrence in posttherapy cancer patients. Isolating and understanding the cell cycle regulatory mechanisms of quiescent cancer cells will be a key component to creation of future therapies that better target CSCs and totally eradicate tumors. Here we review the evidence for quiescent CSC populations and explore potential cell cycle regulators that may serve as future targets for elimination of these cells.

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Activation of two distinct Sox9-EGFP-expressing intestinal stem cell populations during crypt regeneration after irradiation

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.00519.2011 ◽

2012 ◽

Vol 302 (10) ◽

pp. G1111-G1132 ◽

Cited By ~ 97

Author(s):

Laurianne Van Landeghem ◽

M. Agostina Santoro ◽

Adrienne E. Krebs ◽

Amanda T. Mah ◽

Jeffrey J. Dehmer ◽

...

Keyword(s):

Stem Cell ◽

Cell Populations ◽

Intestinal Epithelial ◽

P53 Signaling ◽

Reporter Mice ◽

Radiation Induced ◽

Molecular Phenotypes ◽

Stem Cell Populations ◽

Induced Changes

Recent identification of intestinal epithelial stem cell (ISC) markers and development of ISC reporter mice permit visualization and isolation of regenerating ISCs after radiation to define their functional and molecular phenotypes. Previous studies in uninjured intestine of Sox9-EGFP reporter mice demonstrate that ISCs express low levels of Sox9-EGFP (Sox9-EGFP Low), whereas enteroendocrine cells (EEC) express high levels of Sox9-EGFP (Sox9-EGFP High). We hypothesized that Sox9-EGFP Low ISCs would expand after radiation, exhibit enhanced proliferative capacities, and adopt a distinct gene expression profile associated with rapid proliferation. Sox9-EGFP mice were given 14 Gy abdominal radiation and studied between days 3 and 9 postradiation. Radiation-induced changes in number, growth, and transcriptome of the different Sox9-EGFP cell populations were determined by histology, flow cytometry, in vitro culture assays, and microarray. Microarray confirmed that nonirradiated Sox9-EGFP Low cells are enriched for Lgr5 mRNA and mRNAs enriched in Lgr5-ISCs and identified additional putative ISC markers. Sox9-EGFP High cells were enriched for EEC markers, as well as Bmi1 and Hopx, which are putative markers of quiescent ISCs. Irradiation caused complete crypt loss, followed by expansion and hyperproliferation of Sox9-EGFP Low cells. From nonirradiated intestine, only Sox9-EGFP Low cells exhibited ISC characteristics of forming organoids in culture, whereas during regeneration both Sox9-EGFP Low and High cells formed organoids. Microarray demonstrated that regenerating Sox9-EGFP High cells exhibited transcriptomic changes linked to p53-signaling and ISC-like functions including DNA repair and reduced oxidative metabolism. These findings support a model in which Sox9-EGFP Low cells represent active ISCs, Sox9-EGFP High cells contain radiation-activatable cells with ISC characteristics, and both participate in crypt regeneration.

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Abstract 297: Nkx2–5 Transcriptionally Activates C-kit-ligand And Regulates Cardiac Progenitor Cell Populations

Circulation ◽

10.1161/circ.118.suppl_18.s_279-c ◽

2008 ◽

Vol 118 (suppl_18) ◽

Author(s):

Rebecca L Scotland ◽

Xiaozhong Shi ◽

Anwarul Ferdous ◽

Michael Kyba ◽

Daniel J Garry

Keyword(s):

Transcription Factor ◽

Stem Cell ◽

Progenitor Cell ◽

Transcriptional Regulator ◽

Luciferase Reporter ◽

Transcriptional Networks ◽

Cell Populations ◽

Cardiac Progenitor Cell ◽

Downstream Target ◽

Kit Ligand

C-kit-ligand, also known as stem cell factor, is expressed broadly and has a functional role during hematopoesis, gametogenesis, melanogenesis, mast cell growth and differentiation. Although the receptor for c-kit-ligand, c-kit, has been utilized as a marker to identify cardiac stem cell and progenitor cell populations, the transcriptional regulation and biological function of c-kit-ligand during cardiogenesis has not been defined. Here we demonstrate that c-kit-ligand is a novel downstream target of Nkx2–5. The homeodomain transcription factor, Nkx2–5, is one of the earliest markers of the cardiac lineage and mice lacking this transcription factor are nonviable. To identify potential Nkx2–5 downstream target genes, we utilized ES/EBs that were engineered to overexpress Nkx2–5 and undertook transcriptome analysis of embyroid bodies with and without Nkx2–5 induction. We observed a significant increase in c-kit-ligand expression following Nkx2–5 induction suggesting a role for Nkx2–5 in the activation of c-kit-ligand. Furthermore, analysis of the c-kit-ligand promoter revealed three evolutionarily conserved Nkx2–5 response elements, supporting the notion that Nkx2–5 is a transcriptional regulator of gene expression. We undertook transcriptional assays and transfected the c-kit-ligand promoter-luciferase reporter in the absence and presence of increasing amounts of Nkx2–5. We observed that Nkx2–5, in a dose dependent fashion, was a potent transcriptional activator of c-kit-ligand. These studies enhance our understanding of Nkx2–5 mediated transcriptional networks and further emphasize that Nkx2–5 is an important transcriptional regulator of cardiac progenitor cell populations.

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The Adipose-derived Stem Cell: Looking Back and Looking Ahead

Molecular Biology of the Cell ◽

10.1091/mbc.e09-07-0589 ◽

2010 ◽

Vol 21 (11) ◽

pp. 1783-1787 ◽

Cited By ~ 217

Author(s):

Patricia A. Zuk

Keyword(s):

Stem Cell ◽

Historical Perspective ◽

Es Cells ◽

Adult Stem Cell ◽

Stem Cell Population ◽

Cell Populations ◽

Stem Cell Populations ◽

New Applications ◽

Adipose Derived Stem Cell ◽

Looking Back

In 2002, researchers at UCLA published a manuscript in Molecular Biology of the Cell describing a novel adult stem cell population isolated from adipose tissue—the adipose-derived stem cell (ASC). Since that time, the ASC has gone on to be one of the most popular adult stem cell populations currently being used in the stem cell field. With multilineage mesodermal potential and possible ectodermal and endodermal potentials also, the ASC could conceivably be an alternate to pluripotent ES cells in both the lab and in the clinic. In this retrospective article, a historical perspective on the ASC is given together with exciting new applications for the stem cell being considered today.

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The Use of Endothelial Progenitor Cells for the Regeneration of Musculoskeletal and Neural Tissues

Stem Cells International ◽

10.1155/2017/1960804 ◽

2017 ◽

Vol 2017 ◽

pp. 1-7 ◽

Cited By ~ 12

Author(s):

Naosuke Kamei ◽

Kivanc Atesok ◽

Mitsuo Ochi

Keyword(s):

Bone Marrow ◽

Clinical Trials ◽

Endothelial Cells ◽

Stem Cell ◽

Progenitor Cells ◽

Tissue Repair ◽

Cell Populations ◽

Neural Tissues ◽

Cell Source ◽

Stem Cell Populations

Endothelial progenitor cells (EPCs) derived from bone marrow and blood can differentiate into endothelial cells and promote neovascularization. In addition, EPCs are a promising cell source for the repair of various types of vascularized tissues and have been used in animal experiments and clinical trials for tissue repair. In this review, we focused on the kinetics of endogenous EPCs during tissue repair and the application of EPCs or stem cell populations containing EPCs for tissue regeneration in musculoskeletal and neural tissues including the bone, skeletal muscle, ligaments, spinal cord, and peripheral nerves. EPCs can be mobilized from bone marrow and recruited to injured tissue to contribute to neovascularization and tissue repair. In addition, EPCs or stem cell populations containing EPCs promote neovascularization and tissue repair through their differentiation to endothelial cells or tissue-specific cells, the upregulation of growth factors, and the induction and activation of endogenous stem cells. Human peripheral blood CD34(+) cells containing EPCs have been used in clinical trials of bone repair. Thus, EPCs are a promising cell source for the treatment of musculoskeletal and neural tissue injury.

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