STEM-14. THE WRAD COMPLEX REPRESENTS A THERAPEUTIC TARGET FOR CANCER STEM CELLS IN GLIOBLASTOMA

2021 ◽  
Vol 23 (Supplement_6) ◽  
pp. vi23-vi24
Author(s):  
Kelly Mitchell ◽  
Joseph Alvarado ◽  
Christopher Goins ◽  
Steven Martinez ◽  
Jonathan Macdonald ◽  
...  
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Transcription Factors ◽  
Cancer Stem Cells ◽  
Molecular Mechanisms ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Self Renewal ◽  
Stem Cell Maintenance ◽  
Cell Maintenance

Abstract Glioblastoma (GBM) progression and resistance to conventional therapies is driven in part by cells within the tumor with stem cell properties including quiescence, self-renewal and drug efflux potential. It is thought that eliminating these cancer stem cells (CSCs) is a key component to successful clinical management of GBM. However, currently, few known molecular mechanisms driving CSCs can be exploited for therapeutic development. Core transcription factors such as SOX2, OLIG2, OCT4 and NANOG maintain the CSC state in GBM. Our laboratory recently uncovered a self-renewal signaling axis involving RBBP5 that is necessary and sufficient for CSC maintenance through driving expression of these core stem cell maintenance transcription factors. RBBP5 is a component of the WRAD complex, which promotes Lys4 methylation of histone H3 to positively regulate transcription. We hypothesized that targeting RBBP5 could be a means to disrupt epigenetic programs that maintain CSCs in stemness transcriptional states. We found that genetic and pharmacologic inhibition of the WRAD complex reduced CSC growth, self-renewal and tumor initiation potential. WRAD inhibitors partially dissembled the WRAD complex and reduced H3K4 trimethylation both globally and at the promoters of key stem cell maintenance transcription factors. Using a CSC reporter system, we demonstrated that WRAD complex inhibition decreased growth of SOX2/OCT4 expressing CSCs in a concentration-dependent manner as quantified by live imaging. Overall, our studies assess the function of the WRAD complex and the effect of WRAD complex inhibitors in preclinical models and specifically on the stem cell state for the first time in GBM. Studying the functions of the WRAD complex in CSCs may improve understanding of GBM pathogenesis and elucidate how CSCs survive despite aggressive chemotherapy and radiation. Our ongoing studies aim to develop brain penetrant inhibitors targeting the WRAD complex as an anti-CSC strategy that could potentially synergize with standard of care treatments.

scholarly journals Wnt5a Signaling in Normal and Cancer Stem Cells

2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
Yan Zhou ◽  
Thomas J. Kipps ◽  
Suping Zhang
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Cancer Progression ◽  
Molecular Mechanisms ◽  
Migration And Invasion ◽  
Target Cells ◽  
Dependent Manner ◽  
Self Renewal ◽  
Surface Receptors ◽  
Canonical Wnt

Wnt5a is involved in activating several noncanonical Wnt signaling pathways, which can inhibit or activate canonical Wnt/β-catenin signaling pathway in a receptor context-dependent manner. Wnt5a signaling is critical for regulating normal developmental processes, including stem cell self-renewal, proliferation, differentiation, migration, adhesion, and polarity. Moreover, the aberrant activation or inhibition of Wnt5a signaling is emerging as an important event in cancer progression, exerting both oncogenic and tumor suppressive effects. Recent studies show the involvement of Wnt5a signaling in regulating normal and cancer stem cell self-renewal, cancer cell proliferation, migration, and invasion. In this article, we review recent findings regarding the molecular mechanisms and roles of Wnt5a signaling in stem cells in embryogenesis and in the normal or neoplastic breast or ovary, highlighting that Wnt5a may have different effects on target cells depending on the surface receptors expressed by the target cell.

Essential Role of Jun Family Transcription Factors in PU.1-Induced Leukemic Stem Cell Transformation.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 463-463 ◽  
Author(s):  
Ulrich Steidl ◽  
Frank Rosenbauer ◽  
Roel G.W Verhaak ◽  
Xuesong Gu ◽  
Hasan H. Otu ◽  
...  
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Transcription Factors ◽  
Malignant Transformation ◽  
Molecular Mechanisms ◽  
Target Cells ◽  
Leukemic Stem Cell ◽  
Self Renewal ◽  
Hematopoietic Stem ◽  
Transcriptional Pattern

Abstract Knockdown of the expression of the myeloid master regulator PU.1 leads to the development of an immature acute myeloid leukemia (AML) in mice. Recent reports suggest that functional inactivation of PU.1 might also play a role in human AML. However, the molecular mechanisms underlying PU.1-mediated malignant transformation are unknown. We examined leukemic PU.1 knockdown mice and found a 3-fold expansion of lin-, c-kit+, Sca1+ (KLS) hematopoietic stem cells (HSC) as compared to wildtype controls, which was not observed during the preleukemic phase. When we transplanted double-sorted leukemic KLS-HSC into NOD-SCID mice the recipients developed AML after 9–12 weeks indicating that the leukemic stem cells derive from the HSC compartment. This finding prompted us to examine the transcriptome of PU.1 knockdown preleukemic HSC to identify early transcriptional changes underlying their malignant transformation. After lineage-depletion and FACS sorting of preleukemic KLS-HSC we performed linear amplification of RNA by 2 cycles of RT-IVT and hybridized the cRNA with Affymetrix Mouse Genome 430 2.0 arrays. Principal component analysis as well as hierarchical cluster analysis clearly distinguished PU.1 knockdown and wildtype HSC. Several in-vitro targets of PU.1 such as c-Fes, BTK, TFEC, CSF2R, and Ebi3 were downregulated demonstrating that those are also affected in HSC in vivo. Differential expression of 16 genes was corroborated by qRT-PCR. Strikingly, several Jun family transcription factors including c-Jun and JunB were downregulated. Retroviral restoration of c-Jun expression in bone marrow cells of preleukemic mice rescued the PU.1-initiated myelomonocytic differentiation block in this early phase. To target cells in the leukemic stage we applied lentiviral vectors expressing c-Jun or JunB. While c-Jun did not affect leukemic proliferation, lentiviral restoration of JunB led to an 80% reduction of clonogenic growth and a loss of leukemic self-renewal capacity in serial replating assays. Expression analysis of 285 patients with AML confirmed the correlation between PU.1 and JunB downregulation and suggests its relevance in human disease. These results delineate a transcriptional pattern that precedes leukemic transformation in PU.1 knockdown HSC and demonstrate that downregulation of c-Jun and JunB contribute to the development of PU.1-induced AML by blocking differentiation (c-Jun) and increasing self-renewal (JunB). Therefore, examination of disturbed gene expression in preleukemic HSC can identify genes whose dysregulation is essential for leukemic stem cell function and are potential targets for therapeutic interventions.

Hematopoietic Stem Cell Maintenance and Differentiation Are Supported by Embryonic Aorta-Gonad-Mesonephros Region–Derived Endothelium

Blood ◽  
1998 ◽  
Vol 92 (3) ◽  
pp. 908-919 ◽  
Author(s):  
Osamu Ohneda ◽  
Christopher Fennie ◽  
Zhong Zheng ◽  
Christopher Donahue ◽  
Hank La ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Stem Cell ◽  
Hematopoietic Stem Cells ◽  
Progenitor Cells ◽  
Fetal Liver ◽  
Self Renewal ◽  
Hematopoietic Stem ◽  
Stem Cell Maintenance ◽  
Cell Maintenance

Abstract Hematopoietic stem cells are capable of extensive self-renewal and expansion, particularly during embryonic growth. Although the molecular mechanisms involved with stem cell maintenance remain mysterious, it is now clear that an intraembryonic location, the aorta-gonad-mesonephros (AGM) region, is a site of residence and, potentially, amplification of the definitive hematopoietic stem cells that eventually seed the fetal liver and adult bone marrow. Because several studies suggested that morphologically defined hematopoietic stem/progenitor cells in the AGM region appeared to be attached in clusters to the ventrally located endothelium of the dorsal aorta, we derived cell lines from this intraembryonic site using an anti-CD34 antibody to select endothelial cells. Analysis of two different AGM-derived CD34+ cell lines revealed that one, DAS 104-8, efficiently induced fetal-liver hematopoietic stem cells to differentiate down erythroid, myeloid, and B-lymphoid pathways, but it did not mediate self-renewal of these pluripotent cells. In contrast, a second cell line, DAS 104-4, was relatively inefficient at the induction of hematopoietic differentiation. Instead, this line provoked the expansion of early hematopoietic progenitor cells of the lin−CD34+Sca-1+c-Kit+phenotype and was proficient at maintaining fetal liver–derived hematopoietic stem cells able to competitively repopulate the bone marrow of lethally irradiated mice. These data bolster the hypothesis that the endothelium of the AGM region acts to mediate the support and differentiation of hematopoietic stem cells in vivo. © 1998 by The American Society of Hematology.

scholarly journals G protein-coupled receptors in stem cell maintenance and somatic reprogramming to pluripotent or cancer stem cells

BMB Reports ◽  
2015 ◽  
Vol 48 (2) ◽  
pp. 68-80 ◽  
Author(s):  
Hye Yeon Choi ◽  
Subbroto Kumar Saha ◽  
Kyeongseok Kim ◽  
Sangsu Kim ◽  
Gwang-Mo Yang ◽  
...  
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Cancer Stem Cells ◽  
G Protein ◽  
G Protein Coupled Receptors ◽  
Stem Cell Maintenance ◽  
G Protein Coupled ◽  
Cell Maintenance

scholarly journals Oxygenation level as a factor in stem cell maintenance

2006 ◽  
Vol 134 (Suppl. 1) ◽  
pp. 57-63
Author(s):  
Zoran Ivanovic
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Ex Vivo ◽  
Biomedical Literature ◽  
Low Oxygen ◽  
Self Renewal ◽  
Stem Cell Maintenance ◽  
Oxygenation Level ◽  
Cell Maintenance ◽  
Oxygen Concentrations

This article will describe the decade-long genesis of a research project and review its main results. These results point to oxygenation level being a physiological regulator of haematopoietic stem cell maintenance because: (1) very low oxygen concentrations (~0.1%) enable the preservation of the quiescent (G0) stem cell pool; (2) low oxygen concentrations (~1%) are compatible with the proliferation of primitive stem cells but inhibit their differentiation, i.e. enable their self-renewal; (3) moderately low oxygen concentrations (~3%) allow a balance between differentiation and self-renewal, permitting the simultaneous amplification of progenitors and the maintenance of stem cell activity; and (4) very high oxygen concentrations, like those in the air (20-21%), enhance the differentiation of primitive stem cells, abrogating their self-renewal capacity. In spite of the fact that these oxygen concentrations do not exist in tissues in vivo, they are usually used for in vitro cell growth. These results represent a new insight into the regulatory mechanisms of haematopoiesis. In that light they are cited in top biomedical literature and accepted as being relevant to the development of tissue and cell engineering. In that respect, we are working on the adaptation of culture oxygenation to improve existent ex vivo expansion techniques. We are also trying to improve the techniques of ex vivo production of red blood cells in the same manner. Our other ongoing research projects are directed at improving the conservation of stem cells at low temperatures (but above freezing point) within a liquid medium, by decreasing oxygen and increasing CO2 concentrations.

scholarly journals Exogenous Cripto-1 Suppresses Self-Renewal of Cancer Stem Cell Model

2018 ◽  
Vol 19 (11) ◽  
pp. 3345 ◽  
Author(s):  
Md Alam ◽  
Ryota Takahashi ◽  
Said Afify ◽  
Aung Oo ◽  
Kazuki Kumon ◽  
...  
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Cancer Stem Cells ◽  
Cancer Stem Cell ◽  
Stop Codon ◽  
Site Directed Mutagenesis ◽  
Soluble Form ◽  
Dependent Manner ◽  
Self Renewal ◽  
Mesenchymal Transition

Cripto-1 is a glycophosphatidylinositol (GPI) anchored signaling protein of epidermal growth factor (EGF)-Cripto-1-FRL1-Cryptic (CFC) family and plays a significant role in the early developmental stages and in the different types of cancer cells, epithelial to mesenchymal transition and tumor angiogenesis. Previously, we have developed cancer stem cells (miPS-LLCcm) from mouse iPSCs by culturing them in the presence of conditioned medium of Lewis Lung Carcinoma (LLC) cells for four weeks. Nodal and Cripto-1 were confirmed to be expressed in miPS-LLCcm cells by quantitative reverse transcription PCR (rt-qPCR) implying that Cr-1 was required in maintaining stemness. To investigate the biological effect of adding exogenous soluble CR-1 to the cancer stem cells, we have prepared a C-terminally truncated soluble form of recombinant human CR-1 protein (rhsfCR-1), in which the GPI anchored moiety was removed by substitution of a stop codon through site-directed mutagenesis. rhsfCR-1 effectively suppressed the proliferation and sphere forming ability of miPS-LLCcm cells in a dose-dependent manner in the range of 0 to 5 µg/mL, due to the suppression of Nodal-Cripto-1/ALK4/Smad2 signaling pathway. Frequency of sphere-forming cells was dropped from 1/40 to 1/69 by rhsfCR-1 at 1 µg/mL. Moreover, rhsfCR-1 in the range of 0 to 1 µg/mL also limited the differentiation of miPS-LLCcm cells into vascular endothelial cells probably due to the suppression of self-renewal, which should reduce the number of cells with stemness property. As demonstrated by a soluble form of exogenous Cripto-1 in this study, the efficient blockade would be an attractive way to study Cripto-1 dependent cancer stem cell properties for therapeutic application.

Hematopoietic Stem Cell Maintenance and Differentiation Are Supported by Embryonic Aorta-Gonad-Mesonephros Region–Derived Endothelium

Blood ◽  
1998 ◽  
Vol 92 (3) ◽  
pp. 908-919 ◽  
Author(s):  
Osamu Ohneda ◽  
Christopher Fennie ◽  
Zhong Zheng ◽  
Christopher Donahue ◽  
Hank La ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Stem Cell ◽  
Hematopoietic Stem Cells ◽  
Progenitor Cells ◽  
Fetal Liver ◽  
Self Renewal ◽  
Hematopoietic Stem ◽  
Stem Cell Maintenance ◽  
Cell Maintenance

Hematopoietic stem cells are capable of extensive self-renewal and expansion, particularly during embryonic growth. Although the molecular mechanisms involved with stem cell maintenance remain mysterious, it is now clear that an intraembryonic location, the aorta-gonad-mesonephros (AGM) region, is a site of residence and, potentially, amplification of the definitive hematopoietic stem cells that eventually seed the fetal liver and adult bone marrow. Because several studies suggested that morphologically defined hematopoietic stem/progenitor cells in the AGM region appeared to be attached in clusters to the ventrally located endothelium of the dorsal aorta, we derived cell lines from this intraembryonic site using an anti-CD34 antibody to select endothelial cells. Analysis of two different AGM-derived CD34+ cell lines revealed that one, DAS 104-8, efficiently induced fetal-liver hematopoietic stem cells to differentiate down erythroid, myeloid, and B-lymphoid pathways, but it did not mediate self-renewal of these pluripotent cells. In contrast, a second cell line, DAS 104-4, was relatively inefficient at the induction of hematopoietic differentiation. Instead, this line provoked the expansion of early hematopoietic progenitor cells of the lin−CD34+Sca-1+c-Kit+phenotype and was proficient at maintaining fetal liver–derived hematopoietic stem cells able to competitively repopulate the bone marrow of lethally irradiated mice. These data bolster the hypothesis that the endothelium of the AGM region acts to mediate the support and differentiation of hematopoietic stem cells in vivo. © 1998 by The American Society of Hematology.

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