1
|
Luo H, Cortés-López M, Tam CL, Xiao M, Wakiro I, Chu KL, Pierson A, Chan M, Chang K, Yang X, Fecko D, Han G, Ahn EYE, Morris QD, Landau DA, Kharas MG. SON is an essential m 6A target for hematopoietic stem cell fate. Cell Stem Cell 2023; 30:1658-1673.e10. [PMID: 38065069 PMCID: PMC10752439 DOI: 10.1016/j.stem.2023.11.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Revised: 09/23/2023] [Accepted: 11/09/2023] [Indexed: 12/18/2023]
Abstract
Stem cells regulate their self-renewal and differentiation fate outcomes through both symmetric and asymmetric divisions. m6A RNA methylation controls symmetric commitment and inflammation of hematopoietic stem cells (HSCs) through unknown mechanisms. Here, we demonstrate that the nuclear speckle protein SON is an essential m6A target required for murine HSC self-renewal, symmetric commitment, and inflammation control. Global profiling of m6A identified that m6A mRNA methylation of Son increases during HSC commitment. Upon m6A depletion, Son mRNA increases, but its protein is depleted. Reintroduction of SON rescues defects in HSC symmetric commitment divisions and engraftment. Conversely, Son deletion results in a loss of HSC fitness, while overexpression of SON improves mouse and human HSC engraftment potential by increasing quiescence. Mechanistically, we found that SON rescues MYC and suppresses the METTL3-HSC inflammatory gene expression program, including CCL5, through transcriptional regulation. Thus, our findings define a m6A-SON-CCL5 axis that controls inflammation and HSC fate.
Collapse
Affiliation(s)
- Hanzhi Luo
- Molecular Pharmacology Program, Center for Cell Engineering, Center for Stem Cell Biology, Center for Experimental Therapeutics, Center for Hematologic Malignancies, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Mariela Cortés-López
- New York Genome Center, New York, NY, USA; Meyer Cancer Center, Weill Cornell Medicine, New York, NY, USA; Institute of Computational Biomedicine, Weill Cornell Medicine, New York, NY, USA
| | - Cyrus L Tam
- Computational and Systems Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA; Tri-Institutional Training Program in Computational Biology and Medicine, Weill Cornell Medicine, New York, NY, USA
| | - Michael Xiao
- Molecular Pharmacology Program, Center for Cell Engineering, Center for Stem Cell Biology, Center for Experimental Therapeutics, Center for Hematologic Malignancies, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Isaac Wakiro
- Molecular Pharmacology Program, Center for Cell Engineering, Center for Stem Cell Biology, Center for Experimental Therapeutics, Center for Hematologic Malignancies, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Karen L Chu
- Molecular Pharmacology Program, Center for Cell Engineering, Center for Stem Cell Biology, Center for Experimental Therapeutics, Center for Hematologic Malignancies, Memorial Sloan Kettering Cancer Center, New York, NY, USA; Department of Pharmacology, Weill Cornell School of Medical Sciences, New York, NY, USA
| | - Aspen Pierson
- Molecular Pharmacology Program, Center for Cell Engineering, Center for Stem Cell Biology, Center for Experimental Therapeutics, Center for Hematologic Malignancies, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Mandy Chan
- Molecular Pharmacology Program, Center for Cell Engineering, Center for Stem Cell Biology, Center for Experimental Therapeutics, Center for Hematologic Malignancies, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Kathryn Chang
- Molecular Pharmacology Program, Center for Cell Engineering, Center for Stem Cell Biology, Center for Experimental Therapeutics, Center for Hematologic Malignancies, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Xuejing Yang
- Molecular Pharmacology Program, Center for Cell Engineering, Center for Stem Cell Biology, Center for Experimental Therapeutics, Center for Hematologic Malignancies, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Daniel Fecko
- Molecular Pharmacology Program, Center for Cell Engineering, Center for Stem Cell Biology, Center for Experimental Therapeutics, Center for Hematologic Malignancies, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Grace Han
- Molecular Pharmacology Program, Center for Cell Engineering, Center for Stem Cell Biology, Center for Experimental Therapeutics, Center for Hematologic Malignancies, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Eun-Young Erin Ahn
- Department of Pathology, Division of Molecular and Cellular Pathology, University of Alabama at Birmingham, Birmingham, AL, USA; O'Neal Comprehensive Cancer Center, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Quaid D Morris
- Computational and Systems Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA; Tri-Institutional Training Program in Computational Biology and Medicine, Weill Cornell Medicine, New York, NY, USA
| | - Dan A Landau
- New York Genome Center, New York, NY, USA; Meyer Cancer Center, Weill Cornell Medicine, New York, NY, USA; Institute of Computational Biomedicine, Weill Cornell Medicine, New York, NY, USA
| | - Michael G Kharas
- Molecular Pharmacology Program, Center for Cell Engineering, Center for Stem Cell Biology, Center for Experimental Therapeutics, Center for Hematologic Malignancies, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
| |
Collapse
|
2
|
Dassie F, Albiero M, Bettini S, Cappellari R, Milan G, Ciciliot S, Naggert JK, Avogaro A, Vettor R, Maffei P, Fadini GP. Hematopoietic Stem Cells and Metabolic Deterioration in Alström Syndrome, a Rare Genetic Model of the Metabolic Syndrome. Endocrinology 2023; 164:7005410. [PMID: 36702623 DOI: 10.1210/endocr/bqad011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Revised: 01/11/2023] [Accepted: 01/13/2023] [Indexed: 01/28/2023]
Abstract
Alström syndrome (AS) is a rare genetic disease caused by ALMS1 mutations, characterized by short stature, and vision and hearing loss. Patients with AS develop the metabolic syndrome, long-term organ complications, and die prematurely. We explored the association between AS and a shortage of hematopoietic stem/progenitor cells (HSPCs), which is linked to metabolic diseases and predicts diabetic complications. We included patients with AS at a national referral center. We measured HSPCs with flow cytometry at baseline and follow-up. We followed patients up to January 2022 for metabolic worsening and end-organ damage. We evaluated HSPC levels and mobilization as well as bone marrow histology in a murine model of AS. In 23 patients with AS, we found significantly lower circulating HSPCs than in healthy blood donors (-40%; P = .002) and age/sex-matched patients (-25%; P = .022). Longitudinally, HSPCs significantly declined by a further 20% in patients with AS over a median of 36 months (interquartile range 30-44). Patients with AS who displayed metabolic deterioration over 5.3 years had lower levels of HSPCs, both at baseline and at last observation, than those who did not deteriorate. Alms1-mutated mice were obese and insulin resistant and displayed significantly reduced circulating HSPCs, despite no overt hematological abnormality. Contrary to what was observed in diabetic mice, HSPC mobilization and bone marrow structure were unaffected. We found depletion of HSPCs in patients with AS, which was recapitulated in Alms1-mutated mice. Larger and longer studies will be needed to establish HSPCs shortage as a driver of metabolic deterioration leading to end-organ damage in AS.
Collapse
Affiliation(s)
- Francesca Dassie
- Department of Medicine, University of Padova, 35128 Padova, Italy
| | - Mattia Albiero
- Department of Medicine, University of Padova, 35128 Padova, Italy
- Veneto Institute of Molecular Medicine, 35128 Padova, Italy
| | - Silvia Bettini
- Department of Medicine, University of Padova, 35128 Padova, Italy
| | | | - Gabriella Milan
- Department of Medicine, University of Padova, 35128 Padova, Italy
| | | | | | - Angelo Avogaro
- Department of Medicine, University of Padova, 35128 Padova, Italy
| | - Roberto Vettor
- Department of Medicine, University of Padova, 35128 Padova, Italy
| | - Pietro Maffei
- Department of Medicine, University of Padova, 35128 Padova, Italy
| | - Gian Paolo Fadini
- Department of Medicine, University of Padova, 35128 Padova, Italy
- Veneto Institute of Molecular Medicine, 35128 Padova, Italy
| |
Collapse
|
3
|
Growth dynamics of breast cancer stem cells: effects of self-feedback and EMT mechanisms. Theory Biosci 2022; 141:297-311. [PMID: 35921025 DOI: 10.1007/s12064-022-00374-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Accepted: 07/06/2022] [Indexed: 10/16/2022]
Abstract
Breast cancer stem cells (BCSCs) with the ability to self-renew and differentiate have been identified in primary breast cancer tissues and cell lines. The BCSCs are often resistant to traditional radiation and/or chemotherapies. Previous studies have also shown that successful therapy must eradicate cancer stem cells. The purpose of this paper is to develop a mathematical model with self-feedback mechanism to illustrate the issues regarding the difficulties of absolutely eliminating a breast cancer. In addition, we introduce the mechanism of the epithelial-mesenchymal transition (EMT) to investigate the influence of EMT on the effects of breast cancer growth and treatment. Results indicate that the EMT mechanism facilitates the growth of breast cancer and makes breast cancer more difficult to be cured. Therefore, targeting the signals involved in EMT can halt tumor progression in breast cancer. Finally, we apply the experimental data to carry out numerical simulations and validate our theoretical conclusions.
Collapse
|
4
|
Ratajczak MZ, Kucia M. Extracellular Adenosine Triphosphate (eATP) and Its Metabolite, Extracellular Adenosine (eAdo), as Opposing "Yin-Yang" Regulators of Nlrp3 Inflammasome in the Trafficking of Hematopoietic Stem/Progenitor Cells. Front Immunol 2021; 11:603942. [PMID: 33584673 PMCID: PMC7878390 DOI: 10.3389/fimmu.2020.603942] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Accepted: 12/14/2020] [Indexed: 12/17/2022] Open
Abstract
Nlrp3 inflammasome plays a pleiotropic role in hematopoietic cells. On the one hand, physiological activation of this intracellular protein complex is crucial to maintaining normal hematopoiesis and the trafficking of hematopoietic stem progenitor cells (HSPCs). On the other hand, its hyperactivation may lead to cell death by pyroptosis, and prolonged activity is associated with sterile inflammation of the BM and, as a consequence, with the HSPCs aging and origination of myelodysplasia and leukemia. Thus, we need to understand better this protein complex’s actions to define the boundaries of its safety window and study the transition from being beneficial to being detrimental. As demonstrated, the Nlrp3 inflammasome is expressed and active both in HSPCs and in the non-hematopoietic cells that are constituents of the bone marrow (BM) microenvironment. Importantly, the Nlrp3 inflammasome responds to mediators of purinergic signaling, and while extracellular adenosine triphosphate (eATP) activates this protein complex, its metabolite extracellular adenosine (eAdo) has the opposite effect. In this review, we will discuss and focus on the physiological consequences of the balance between eATP and eAdo in regulating the trafficking of HSPCs in an Nlrp3 inflammasome-dependent manner, as seen during pharmacological mobilization from BM into peripheral blood (PB) and in the reverse mechanism of homing from PB to BM and engraftment. We propose that both mediators of purinergic signaling and the Nlrp3 inflammasome itself may become important therapeutic targets in optimizing the trafficking of HSPCs in clinical settings.
Collapse
Affiliation(s)
- Mariusz Z Ratajczak
- Stem Cell Institute at Division of Hematology, Department of Medicine and James Graham Brown Cancer Center, University of Louisville, KY, United States.,Center for Preclinical Studies and Technology, Department of Regenerative Medicine Medical University of Warsaw, Warsaw, Poland
| | - Magda Kucia
- Stem Cell Institute at Division of Hematology, Department of Medicine and James Graham Brown Cancer Center, University of Louisville, KY, United States.,Center for Preclinical Studies and Technology, Department of Regenerative Medicine Medical University of Warsaw, Warsaw, Poland
| |
Collapse
|
5
|
Balise VD, Saito-Reis CA, Gillette JM. Tetraspanin Scaffold Proteins Function as Key Regulators of Hematopoietic Stem Cells. Front Cell Dev Biol 2020; 8:598. [PMID: 32754593 PMCID: PMC7381308 DOI: 10.3389/fcell.2020.00598] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Accepted: 06/19/2020] [Indexed: 02/06/2023] Open
Abstract
Hematopoietic stem and progenitor cells (HSPCs) are responsible for the development, maintenance, and regeneration of all the blood forming cells in the body, and as such, are critical for a number of patient therapies. For successful HSPC transplantation, stem cells must traffic through the blood and home to the bone marrow (BM) microenvironment or “niche,” which is composed of soluble factors, matrix proteins, and supportive cells. HSPC adhesion to, and signaling with, cellular and extracellular components of the niche provide instructional cues to balance stem cell self-renewal and differentiation. In this review, we will explore the regulation of these stem cell properties with a focus on the tetraspanin family of membrane proteins. Tetraspanins are molecular scaffolds that uniquely function to distribute proteins into highly organized microdomains comprising adhesion, signaling, and adaptor proteins. As such, tetraspanins contribute to many aspects of cell physiology as mediators of cell adhesion, trafficking, and signaling. We will summarize the many reports that identify tetraspanins as markers of specific HSPC populations. Moreover, we will discuss the various studies establishing the functional importance of tetraspanins in the regulation of essential HSPC processes including quiescence, migration, and niche adhesion. When taken together, studies outlined in this review suggest that several tetraspanins may serve as potential targets to modulate HSPC interactions with the BM niche, ultimately impacting future HSPC therapies.
Collapse
Affiliation(s)
- Victoria D Balise
- Department of Pathology, University of New Mexico Health Sciences Center, Albuquerque, NM, United States
| | - Chelsea A Saito-Reis
- Department of Pathology, University of New Mexico Health Sciences Center, Albuquerque, NM, United States
| | - Jennifer M Gillette
- Department of Pathology, University of New Mexico Health Sciences Center, Albuquerque, NM, United States.,Comprehensive Cancer Center, The University of New Mexico, Albuquerque, NM, United States
| |
Collapse
|
6
|
Wang Y, Tian H, Cai W, Lian Z, Bhavanasi D, Wu C, Sato T, Kurokawa M, Wu D, Fu L, Wang H, Shen H, Liang D, Huang J. Tracking hematopoietic precursor division ex vivo in real time. Stem Cell Res Ther 2018; 9:16. [PMID: 29361987 PMCID: PMC5781326 DOI: 10.1186/s13287-017-0767-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Revised: 12/19/2017] [Accepted: 12/28/2017] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND Deciphering molecular mechanisms underlying the division of hematopoietic stem cells (HSCs) and malignant precursors would improve our understanding of the basis of stem cell-fate decisions and oncogenic transformation. METHODS Using a novel reporter of hematopoietic precursor, Evi1-GFP, we tracked the division of hematopoietic precursors in culture in real time. RESULTS First, we confirmed that Evi1-GFP is a faithful reporter of HSC activity and identified three dividing patterns of HSCs: symmetric renewal, symmetric differentiation, and asymmetric division. Moreover, we found that the cytokine and growth factor combination (STIF) promotes symmetric renewal, whereas OP9 stromal cells balance symmetric renewal and differentiation of HSCs ex vivo. Interestingly, we found that Tet2 knockout HSCs underwent more symmetric differentiation in culture compared with the wild-type control. Intriguingly, OP9 stromal cells reverse the phenotype of Tet2 knockout HSCs ex vivo. Furthermore, we demonstrated that Tet2 -/- ;Flt3ITD acute myeloid leukemia (AML) precursors primarily underwent symmetric renewal divisions in culture. Mechanistically, we demonstrated that inhibiting DNA methylation can reverse the aberrant division phenotypes of Tet2 -/- and Tet2 -/- ;FLT3ITD precursors, suggesting that abnormal DNA methylation plays an important role in controlling (pre-)leukemic precursor fate decision ex vivo. CONCLUSIONS Our study exploited a new system to explore the molecular mechanisms of the regulation of benign and malignant hematopoietic precursor division ex vivo. The knowledge learned from these studies will provide new insights into the molecular mechanisms of HSC fate decision and leukemogenesis.
Collapse
Affiliation(s)
- Yuchen Wang
- Department of Physiology & Pathophysiology, School of Basic Medical Science, Peking University, Beijing, People's Republic of China.,Department of Pathology and Laboratory Medicine, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, 19140, USA
| | - Hong Tian
- Department of Pathology and Laboratory Medicine, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, 19140, USA.,Jiangsu Institute of Hematology, The First Affiliated Hospital of Soochow University, Suzhou, People's Republic of China
| | - Wenzhi Cai
- Department of Pathology and Laboratory Medicine, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, 19140, USA.,Jiangsu Institute of Hematology, The First Affiliated Hospital of Soochow University, Suzhou, People's Republic of China
| | - Zhaorui Lian
- Department of Pathology and Laboratory Medicine, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, 19140, USA
| | - Dheeraj Bhavanasi
- Department of Medicine (Hematology-Oncology), University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, USA
| | - Chao Wu
- Department of Pathology and Laboratory Medicine, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, 19140, USA.,Fox Chase Cancer Center, Philadelphia, Pennsylvania, USA
| | - Tomohiko Sato
- Department of Hematology and Oncology, University of Tokyo, Bunkyo-ku, Tokyo, 113-8655, Japan
| | - Mineo Kurokawa
- Department of Hematology and Oncology, University of Tokyo, Bunkyo-ku, Tokyo, 113-8655, Japan
| | - Depei Wu
- Jiangsu Institute of Hematology, The First Affiliated Hospital of Soochow University, Suzhou, People's Republic of China
| | - Li Fu
- Department of Physiology and Pathophysiology, School of Basic Medical Science, Tianjin Medical University, Tianjin, 300070, People's Republic of China
| | - Hong Wang
- Center for Metabolic Disease Research, Department of Pharmacology, Lewis Katz School of Medicine, Temple University, Philadelphia, USA
| | - Hao Shen
- Department of Microbiology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, USA
| | - Dong Liang
- Department of Prenatal Diagnosis, Obstetrics and Gynecology Hospital Affiliated to Nanjing Medical University, Nanjing, 210004, Jiangsu, People's Republic of China
| | - Jian Huang
- Department of Pathology and Laboratory Medicine, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, 19140, USA.
| |
Collapse
|
7
|
Bone Marrow Homing and Engraftment Defects of Human Hematopoietic Stem and Progenitor Cells. Mediterr J Hematol Infect Dis 2017; 9:e2017032. [PMID: 28512561 PMCID: PMC5419183 DOI: 10.4084/mjhid.2017.032] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2017] [Accepted: 03/18/2017] [Indexed: 12/31/2022] Open
Abstract
Homing of hematopoietic stem cells (HSC) to their microenvironment niches in the bone marrow is a complex process with a critical role in repopulation of the bone marrow after transplantation. This active process allows for migration of HSC from peripheral blood and their successful anchoring in bone marrow before proliferation. The process of engraftment starts with the onset of proliferation and must, therefore, be functionally dissociated from the former process. In this overview, we analyze the characteristics of stem cells (SCs) with particular emphasis on their plasticity and ability to find their way home to the bone marrow. We also address the problem of graft failure which remains a significant contributor to morbidity and mortality after allogeneic hematopoietic stem cell transplantation (HSCT). Within this context, we discuss non-malignant and malignant hematological disorders treated with reduced-intensity conditioning regimens or grafts from human leukocyte antigen (HLA)-mismatched donors.
Collapse
|
8
|
Optimal architecture of differentiation cascades with asymmetric and symmetric stem cell division. J Theor Biol 2016; 407:106-117. [DOI: 10.1016/j.jtbi.2016.07.029] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2015] [Revised: 07/02/2016] [Accepted: 07/20/2016] [Indexed: 11/23/2022]
|
9
|
Abstract
Hematopoietic stem cells (HSC) undergo multilineage differentiation or self-renewal to maintain normal hematopoiesis and to sustain the size of the HSC pool throughout life. These processes are determined by a complex interplay of molecular signals between HSC and other cellular components such as osteoblasts (OB), stromal cells, endothelial cells, and a number of extracellular matrix (ECM) proteins. Through changes in its physical properties within the bone marrow (BM) microenvironment, collagen, which is one of the most critical ECM proteins, can modulate HSC function and maintenance of the competence of the hematopoietic niche (HN). At present, there is no consensus as to how different cellular elements of the niche collaborate and interact to promote HSC self-renewal or differentiation to maintain hematopoiesis. Deciphering these interactions and the impact of mechanical properties of the collagen microstructures within the HN has critical clinical implications in the areas of stem cell homing, engraftment, and maintenance of HSC function. In this chapter, we describe several of the in vitro methodologies for establishing and maintaining HSC in vitro including the isolation of OB, stromal cells, and hematopoietic progenitor cells, as well as the establishment of both two-dimensional (2D) and three-dimensional (3D) coculture systems.
Collapse
|
10
|
Shahriyari L, Komarova NL. Symmetric vs. asymmetric stem cell divisions: an adaptation against cancer? PLoS One 2013; 8:e76195. [PMID: 24204602 PMCID: PMC3812169 DOI: 10.1371/journal.pone.0076195] [Citation(s) in RCA: 81] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2013] [Accepted: 08/21/2013] [Indexed: 01/17/2023] Open
Abstract
Traditionally, it has been held that a central characteristic of stem cells is their ability to divide asymmetrically. Recent advances in inducible genetic labeling provided ample evidence that symmetric stem cell divisions play an important role in adult mammalian homeostasis. It is well understood that the two types of cell divisions differ in terms of the stem cells' flexibility to expand when needed. On the contrary, the implications of symmetric and asymmetric divisions for mutation accumulation are still poorly understood. In this paper we study a stochastic model of a renewing tissue, and address the optimization problem of tissue architecture in the context of mutant production. Specifically, we study the process of tumor suppressor gene inactivation which usually takes place as a consequence of two “hits”, and which is one of the most common patterns in carcinogenesis. We compare and contrast symmetric and asymmetric (and mixed) stem cell divisions, and focus on the rate at which double-hit mutants are generated. It turns out that symmetrically-dividing cells generate such mutants at a rate which is significantly lower than that of asymmetrically-dividing cells. This result holds whether single-hit (intermediate) mutants are disadvantageous, neutral, or advantageous. It is also independent on whether the carcinogenic double-hit mutants are produced only among the stem cells or also among more specialized cells. We argue that symmetric stem cell divisions in mammals could be an adaptation which helps delay the onset of cancers. We further investigate the question of the optimal fraction of stem cells in the tissue, and quantify the contribution of non-stem cells in mutant production. Our work provides a hypothesis to explain the observation that in mammalian cells, symmetric patterns of stem cell division seem to be very common.
Collapse
Affiliation(s)
- Leili Shahriyari
- Department of Mathematics, University of California Irvine, Irvine, California, United States of America
| | | |
Collapse
|
11
|
Du W, Amarachintha S, Sipple J, Schick J, Steinbrecher K, Pang Q. Inflammation-mediated notch signaling skews fanconi anemia hematopoietic stem cell differentiation. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2013; 191:2806-17. [PMID: 23926327 PMCID: PMC3773980 DOI: 10.4049/jimmunol.1203474] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Hematopoietic stem cells (HSCs) can either self-renew or differentiate into various types of cells of the blood lineage. Signaling pathways that regulate this choice of self-renewal versus differentiation are currently under extensive investigation. In this study, we report that deregulation of Notch signaling skews HSC differentiation in mouse models of Fanconi anemia (FA), a genetic disorder associated with bone marrow failure and progression to leukemia and other cancers. In mice expressing a transgenic Notch reporter, deletion of the Fanca or Fancc gene enhances Notch signaling in multipotential progenitors (MPPs), which is correlated with decreased phenotypic long-term HSCs and increased formation of MPP1 progenitors. Furthermore, we found an inverse correlation between Notch signaling and self-renewal capacity in FA hematopoietic stem and progenitor cells. Significantly, FA deficiency in MPPs deregulates a complex network of genes in the Notch and canonical NF-κB pathways. Genetic ablation or pharmacologic inhibition of NF-κB reduces Notch signaling in FA MPPs to near wild type level, and blocking either NF-κB or Notch signaling partially restores FA HSC quiescence and self-renewal capacity. These results suggest a functional crosstalk between Notch signaling and NF-κB pathway in regulation of HSC differentiation.
Collapse
Affiliation(s)
- Wei Du
- Division of Experimental Hematology and Cancer Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio 45229
| | - Surya Amarachintha
- Division of Experimental Hematology and Cancer Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio 45229
| | - Jared Sipple
- Division of Experimental Hematology and Cancer Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio 45229
| | - Jonathan Schick
- Division of Experimental Hematology and Cancer Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio 45229
| | - Kris Steinbrecher
- Division of Pediatric Gastroenterology, Hepatology and Nutrition, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio 45229
| | - Qishen Pang
- Division of Experimental Hematology and Cancer Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio 45229
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio 45229
| |
Collapse
|
12
|
Sada A, Tumbar T. New insights into mechanisms of stem cell daughter fate determination in regenerative tissues. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2013; 300:1-50. [PMID: 23273858 DOI: 10.1016/b978-0-12-405210-9.00001-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Stem cells can self-renew and differentiate over extended periods of time. Understanding how stem cells acquire their fates is a central question in stem cell biology. Early work in Drosophila germ line and neuroblast showed that fate choice is achieved by strict asymmetric divisions that can generate each time one stem and one differentiated cell. More recent work suggests that during homeostasis, some stem cells can divide symmetrically to generate two differentiated cells or two identical stem cells to compensate for stem cell loss that occurred by direct differentiation or apoptosis. The interplay of all these factors ensures constant tissue regeneration and the maintenance of stem cell pool size. This interplay can be modeled as a population-deterministic dynamics that, at least in some systems, may be described as stochastic behavior. Here, we overview recent progress made on the characterization of stem cell dynamics in regenerative tissues.
Collapse
Affiliation(s)
- Aiko Sada
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York, USA
| | | |
Collapse
|
13
|
Abstract
One of the most intriguing questions in stem cell biology is whether pluripotent stem cells exist in adult tissues. Several groups of investigators employing i) various isolation protocols, ii) detection of surface markers, and iii) experimental in vitro and in vivo models, have reported the presence of cells that possess a pluripotent character in adult tissues. Such cells were assigned various operational abbreviations and names in the literature that added confusion to the field and raised the basic question of whether these are truly distinct or overlapping populations of the same primitive stem cells. Unfortunately, these cells were never characterized side-by-side to address this important issue. Nevertheless, taking into consideration their common features described in the literature, it is very likely that various investigators have described overlapping populations of developmentally early stem cells that are closely related. These different populations of stem cells will be reviewed in this paper.
Collapse
|
14
|
Nakaoka S, Aihara K. Mathematical study on kinetics of hematopoietic stem cells--theoretical conditions for successful transplantation. JOURNAL OF BIOLOGICAL DYNAMICS 2011; 6:836-854. [PMID: 22873618 DOI: 10.1080/17513758.2011.588343] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Numerous haematological diseases occur due to dysfunctions during homeostasis processes of blood cell production. Haematopoietic stem cell transplantation (HSCT) is a therapeutic option for the treatment of haematological malignancy and congenital immunodeficiency. Today, HSCT is widely applied as an alternative method to bone marrow transplantation; however, HSCT can be a risky procedure because of potential side effects and complications after transplantations. Although an optimal regimen to achieve successful HSCT while maintaining quality of life is to be developed, even theoretical considerations such as the evaluations of successful engraftments and proposals of clinical management strategies have not been fully discussed yet. In this paper, we construct and investigate mathematical models that describe the kinetics of hematopoietic stem cell self-renewal and granulopoiesis under the influence of growth factors. Moreover, we derive theoretical conditions for successful HSCT, primarily on the basis of the idea that the basic reproduction number R (0) represents a threshold condition for a population to successfully grow in a given steady-state environment. Successful engraftment of transplanted haematopoietic stem cells (HSCs) is subsequently ensured by employing a concept of dynamical systems theory known as 'persistence'. On the basis of the implications from the modelling study, we discuss how the conditions derived for a successful HSCT are used to link to experimental studies.
Collapse
Affiliation(s)
- Shinji Nakaoka
- FIRST, Aihara Innovative Mathematical Modelling Project, Japan Science and Technology Agency, Institute of Industrial Science, University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo, 153-8505, Japan.
| | | |
Collapse
|
15
|
Zhu X, Zhou X, Lewis MT, Xia L, Wong S. Cancer stem cell, niche and EGFR decide tumor development and treatment response: A bio-computational simulation study. J Theor Biol 2010; 269:138-49. [PMID: 20969880 DOI: 10.1016/j.jtbi.2010.10.016] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2009] [Revised: 10/11/2010] [Accepted: 10/11/2010] [Indexed: 12/11/2022]
Abstract
Recent research in cancer biology has suggested the hypothesis that tumors are initiated and driven by a small group of cancer stem cells (CSCs). Furthermore, cancer stem cell niches have been found to be essential in determining fates of CSCs, and several signaling pathways have been proven to play a crucial role in cellular behavior, which could be two important factors in cancer development. To better understand the progression, heterogeneity and treatment response of breast cancer, especially in the context of CSCs, we propose a mathematical model based on the cell compartment method. In this model, three compartments of cellular subpopulations are constructed: CSCs, progenitor cells (PCs), and terminal differentiated cells (TCs). Moreover, (1) the cancer stem cell niche is, considered by modeling its effect on division patterns (symmetric or asymmetric) of CSCs, and (2) the EGFR signaling pathway is integrated by modeling its role in cell proliferation, apoptosis. Our simulation results indicate that (1) a higher probability for symmetric division of CSC may result in a faster expansion of tumor population, and for a larger number of niches, the tumor grows at a slower rate, but the final tumor volume is larger; (2) higher EGFR expression correlates to tumors with larger volumes while a saturation function is observed, and (3) treatments that inhibit tyrosine kinase activity of EGFR may not only repress the tumor volume, but also decrease the CSCs percentages by shifting CSCs from symmetric divisions to asymmetric divisions. These findings suggest that therapies should be designed to effectively control or eliminate the symmetric division of CSCs and to reduce or destroy the CSC niches.
Collapse
Affiliation(s)
- Xiuwei Zhu
- Key Laboratory of Biomedical Engineering of Ministry of Education, Department of Biomedical Engineering, Zhejiang University, Hangzhou 310027, China
| | | | | | | | | |
Collapse
|
16
|
Nteliopoulos G, Marley SB, Gordon MY. Influence of PI-3K/Akt pathway on Wnt signalling in regulating myeloid progenitor cell proliferation. Evidence for a role of autocrine/paracrine Wnt regulation. Br J Haematol 2009; 146:637-51. [DOI: 10.1111/j.1365-2141.2009.07823.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
17
|
Cord blood stem cell expansion is permissive to epigenetic regulation and environmental cues. Exp Hematol 2009; 37:1084-95. [DOI: 10.1016/j.exphem.2009.05.012] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2009] [Revised: 05/15/2009] [Accepted: 05/28/2009] [Indexed: 11/20/2022]
|
18
|
Huang X, Tian E, Xu Y, Zhang H. The C. elegans engrailed homolog ceh-16 regulates the self-renewal expansion division of stem cell-like seam cells. Dev Biol 2009; 333:337-47. [PMID: 19607822 DOI: 10.1016/j.ydbio.2009.07.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2009] [Revised: 06/01/2009] [Accepted: 07/06/2009] [Indexed: 12/24/2022]
Abstract
Stem cells undergo symmetric and asymmetric division to maintain the dynamic equilibrium of the stem cell pool and also to generate a variety of differentiated cells. The homeostatic mechanism controlling the choice between self-renewal and differentiation of stem cells is poorly understood. We show here that ceh-16, encoding the C. elegans ortholog of the transcription factor Engrailed, controls symmetric and asymmetric division of stem cell-like seam cells. Loss of function of ceh-16 causes certain seam cells, which normally undergo symmetric self-renewal expansion division with both daughters adopting the seam cell fate, to divide asymmetrically with only one daughter retaining the seam cell fate. The human engrailed homolog En2 functionally substitutes the role of ceh-16 in promoting self-renewal expansion division of seam cells. Loss of function of apr-1, encoding the C. elegans homolog of the Wnt signaling component APC, results in transformation of self-renewal maintenance seam cell division to self-renewal expansion division, leading to seam cell hyperplasia. The apr-1 mutation suppresses the seam cell division defect in ceh-16 mutants. Our study reveals that ceh-16 interacts with the Wnt signaling pathway to control the choice between self-renewal expansion and maintenance division and also demonstrates an evolutionarily conserved function of engrailed in promoting cell proliferation.
Collapse
Affiliation(s)
- Xinxin Huang
- College of Life Sciences, Beijing Normal University, Beijing, 100875, PR China
| | | | | | | |
Collapse
|
19
|
Abstract
As an archetype of human adult stem cells that can readily be harvested, enriched and expanded in vitro, mesenchymal stromal cells (MSC) have been reported to be of significance for regenerative medicine. The literature is replete with reports on their developmental potentials in pre-clinical model systems. Different preparative protocols have been shown to yield MSC-like cell cultures or even cell lines, from starting materials as diverse as bone marrow, fat tissue, fetal cord blood and peripheral blood. However, MSC are still ill-defined by physical, phenotypic and functional properties. The quality of preparations from different laboratories varies tremendously and the cell products are notoriously heterogeneous. The source and freshness of the starting material, culture media used, presence of animal sera, cytokines, cell density, number of passages upon culture, etc., all have a significant impact on the (1) cell type components and heterogeneity of the initial population, (2) differential expansion of specific subsets, with different potentials of the end products, and (3) long-term functional fate of MSC as well as other types of progenitor cells that are co-cultivated with them. Consequently, there is an urgent need for the development of reliable reagents, common guidelines and standards for MSC preparations and of precise molecular and cellular markers to define subpopulations with diverse pathways of differentiation and divergent potentials.
Collapse
Affiliation(s)
- A D Ho
- Department of Medicine V, University of Heidelberg, Heidelberg, Germany.
| | | | | |
Collapse
|
20
|
Yang HY, Jeong DK, Kim SH, Chung KJ, Cho EJ, Jin CH, Yang U, Lee SR, Lee DS, Lee TH. Gene expression profiling related to the enhanced erythropoiesis in mouse bone marrow cells. J Cell Biochem 2008; 104:295-303. [PMID: 17990289 DOI: 10.1002/jcb.21620] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Peroxiredoxin II knockout (Prdx II(-/-)) mice had a spontaneous phenotype of hemolytic anemia. In this study, we found that Ter-119(+)CD71(+) cells increased in Prdx II(-/-) mice bone marrow (BM) at 8 weeks of age. We examined the differential expression profiles to bone marrow cells (BMCs) between Prdx II(+/+) and Prdx II(-/-) mice using a cDNA microarray. We identified the 136 candidates were differentially expressed a greater twofold increase or decrease than EPO receptor. In this study, we focused on the up-regulated NBPs during erythropoietic differentiation. According to cDNA microarray results, six NBPs except zfp-127 were up-regulated during erythropoiesis in Prdx II(-/-) mice. Among the six candidates, eIF3-p44, hnRNPH1, G3bp, and Zfpm-1 were dramatically increased at day 7 of the in vitro erythropoietic differentiation of human CD34(+) cells. However, DJ-1 and Rbm3 were slightly increased only at day 12. Our results suggest that up-regulated NBPs might be involved during erythropoietic differentiation.
Collapse
Affiliation(s)
- Hee-Young Yang
- Department of Molecular Medicine, Chonnam National University, Gwangju, South Korea
| | | | | | | | | | | | | | | | | | | |
Collapse
|
21
|
Congdon KL, Reya T. Divide and conquer: how asymmetric division shapes cell fate in the hematopoietic system. Curr Opin Immunol 2008; 20:302-7. [PMID: 18554882 DOI: 10.1016/j.coi.2008.05.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2008] [Revised: 05/08/2008] [Accepted: 05/11/2008] [Indexed: 10/22/2022]
Abstract
A fundamental mechanism by which cells can give rise to daughters with different fates is via asymmetric division. During asymmetric division, a mother cell generates daughter cells that go on to adopt different fates because of differential segregation of cell fate determinants. Although originally characterized in invertebrates, asymmetric division has recently been shown to regulate cell fate decisions in the mammalian hematopoietic system, playing crucial roles in stem cell renewal, lymphocyte activation, and leukemogenesis. These discoveries have opened new doors to understanding how regulation of division pattern contributes to the normal development and function of the immune system as well as how its dysregulation can lead to cancer.
Collapse
Affiliation(s)
- Kendra L Congdon
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC 27710, USA
| | | |
Collapse
|
22
|
Wagner W, Saffrich R, Ho AD. The Stromal Activity of Mesenchymal Stromal Cells. Transfus Med Hemother 2008; 35:185-193. [PMID: 21547116 PMCID: PMC3083286 DOI: 10.1159/000128956] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2007] [Accepted: 12/06/2007] [Indexed: 12/29/2022] Open
Abstract
SUMMARY: The mechanism that regulates self-renewal and differentiation of hematopoietic stem cells (HSC) is a central question in stem cell biology that might ultimately lead to reliable protocols for in vitro expansion of HSC. Cellular fate is governed by cell-cell interaction with the microenvironment in the bone marrow, the stem cell niche. Mesenchymal stromal cells (MSC) are precursors of the cellular components, and they secrete extracellular matrix proteins of the bone marrow stroma. Therefore, MSC feeder layer might provide a suitable in vitro model system for the stem cell niche. In vitro assays demonstrate that MSC maintain the stem cell function of HSC and that MSC from bone marrow have a higher hematopoiesis supportive activity than MSC from adipose tissue. Co-cultivation with MSC might pave the way for expansion of long-term repopulating HSC, and various clinical trials indicate that co-transplantation of HSC and MSC might enhance engraftment. Thus, MSC are promising tools to elucidate the underlying mechanism of the cellular microenvironment. The large variety of preparative protocols for isolation and cultivation of MSC affects their stromal activity. Standardized isolation methods and molecular characterization of MSC are of utmost importance for reproducible isolation of hematopoiesis supportive stromal cells and for their potential clinical application.
Collapse
Affiliation(s)
- Wolfgang Wagner
- Department of Medicine V, University of Heidelberg, Germany
- Department of Physiology and Pathophysiology, University of Heidelberg, Germany
| | | | - Anthony D. Ho
- Department of Medicine V, University of Heidelberg, Germany
| |
Collapse
|
23
|
Abstract
Mesenchymal stem cells (MSC) represent a type of adult stem cells that can easily be isolated from various tissues and expanded in vitro. Past reports on their pluripotency and possible clinical applications have raised hopes and interest in MSC. Multiple designations have been given to different MSC preparations. So far MSC are poorly defined by a combination of physical, phenotypical and functional properties. As MSC could be derived from different tissues as starting material, by diverse isolation protocols, cultured and expanded in different media and conditions, the MSC preparations from different laboratories are highly heterogeneous. All of these variables might have implications (1) on the selection of cell types and the composition of heterogeneous subpopulations; (2) they can selectively favor expansion of different cell populations with totally different potentials; or (3) they might alter the long term fate of adult stem cells upon in vitro culture. The recent controversy on the multilineage differentiation potentials of some specific MSC preparations might be attributed to this lack of common standards. More precise molecular and cellular markers to define subsets of MSC and to standardize the protocols for expansion of MSC are urgently needed.
Collapse
|
24
|
Rajasimha HK, Chinnery PF, Samuels DC. Selection against pathogenic mtDNA mutations in a stem cell population leads to the loss of the 3243A-->G mutation in blood. Am J Hum Genet 2008; 82:333-43. [PMID: 18252214 PMCID: PMC2427290 DOI: 10.1016/j.ajhg.2007.10.007] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2007] [Revised: 09/18/2007] [Accepted: 10/03/2007] [Indexed: 12/30/2022] Open
Abstract
The mutation 3243A-->G is the most common heteroplasmic pathogenic mitochondrial DNA (mtDNA) mutation in humans, but it is not understood why the proportion of this mutation decreases in blood during life. Changing levels of mtDNA heteroplasmy are fundamentally related to the pathophysiology of the mitochondrial disease and correlate with clinical progression. To understand this process, we simulated the segregation of mtDNA in hematopoietic stem cells and leukocyte precursors. Our observations show that the percentage of mutant mtDNA in blood decreases exponentially over time. This is consistent with the existence of a selective process acting at the stem cell level and explains why the level of mutant mtDNA in blood is almost invariably lower than in nondividing (postmitotic) tissues such as skeletal muscle. By using this approach, we derived a formula from human data to correct for the change in heteroplasmy over time. A comparison of age-corrected blood heteroplasmy levels with skeletal muscle, an embryologically distinct postmitotic tissue, provides independent confirmation of the model. These findings indicate that selection against pathogenic mtDNA mutations occurs in a stem cell population.
Collapse
Affiliation(s)
- Harsha Karur Rajasimha
- Virginia Bioinformatics Institute, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061 USA
| | - Patrick F. Chinnery
- Mitochondrial Research Group and Institute of Human Genetics, Newcastle University, The Medical School, Newcastle-upon-Tyne NE2 4HH, UK
| | - David C. Samuels
- Virginia Bioinformatics Institute, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061 USA
| |
Collapse
|
25
|
Chumsri S, Matsui W, Burger AM. Therapeutic implications of leukemic stem cell pathways. Clin Cancer Res 2008; 13:6549-54. [PMID: 18006753 DOI: 10.1158/1078-0432.ccr-07-1088] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
An emerging concept in cancer biology is that a rare population of cancer stem cells exists among the heterogeneous cell mass that constitutes a tumor. This concept is best understood in human myeloid leukemia. Normal and malignant hematopoietic stem cell functions are defined by a common set of critical stemness genes that regulate self-renewal and developmental pathways. Several stemness factors, such as Notch or telomerase, show differential activation in normal hematopoietic versus leukemia stem cells. These differences could be exploited therapeutically even with drugs that are already in clinical use for the treatment of leukemia. The translation of novel and existing leukemic stem cell-directed therapies into clinical practice, however, will require changes in clinical trial design and the inclusion of stem cell biomarkers as correlative end points.
Collapse
Affiliation(s)
- Saranya Chumsri
- Department of Medicine, University of Maryland Marlene and Stewart Greenebaum Cancer Center, Baltimore, MD, USA
| | | | | |
Collapse
|
26
|
Wagner W, Roderburg C, Wein F, Diehlmann A, Frankhauser M, Schubert R, Eckstein V, Ho AD. Molecular and secretory profiles of human mesenchymal stromal cells and their abilities to maintain primitive hematopoietic progenitors. Stem Cells 2007; 25:2638-47. [PMID: 17615262 DOI: 10.1634/stemcells.2007-0280] [Citation(s) in RCA: 178] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Mesenchymal stromal cells (MSC) provide a supportive cellular microenvironment and are able to maintain the self-renewal capacity of hematopoietic progenitor cells (HPC). Isolation procedures for MSC vary extensively, and this may influence their biologic properties. In this study, we have compared human MSC isolated from bone marrow (BM) using two culture conditions, from cord blood (CB), and from adipose tissue (AT). The ability to maintain long-term culture-initiating cell frequency and a primitive CD34(+)CD38(-) immunophenotype was significantly higher for MSC derived from BM and CB compared with those from AT. These results were in line with a significantly higher adhesion of HPC to MSC from BM and CB versus MSC from AT. We have compared the cytokine production of MSC by cytokine antibody arrays, enzyme-linked immunosorbent assay, and a cytometric bead array. There were reproducible differences in the chemokine secretion profiles of various MSC preparations, but there was no clear concordance with differences in their potential to maintain primitive function of HPC. Global gene expression profiles of MSC preparations were analyzed and showed that adhesion proteins including cadherin-11, N-cadherin, vascular cell adhesion molecule 1, neural cell adhesion molecule 1, and integrins were highly expressed in MSC preparations derived from BM and CB. Thus, MSC from BM and CB are superior to MSC from AT for maintenance of primitive HPC. The latter property is associated with specific molecular profiles indicating the significance of cell-cell junctions but not with secretory profiles. Disclosure of potential conflicts of interest is found at the end of this article.
Collapse
Affiliation(s)
- Wolfgang Wagner
- Department of Medicine V, University of Heidelberg, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany.
| | | | | | | | | | | | | | | |
Collapse
|
27
|
Ho AD, Wagner W. The beauty of asymmetry: asymmetric divisions and self-renewal in the haematopoietic system. Curr Opin Hematol 2007; 14:330-6. [PMID: 17534157 DOI: 10.1097/moh.0b013e3281900f12] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
PURPOSE OF REVIEW The hallmark of stem cells is their dual abilities to self-renew and to differentiate into multiple lineages. To fulfill these functions they must undergo asymmetric division. A central question in developmental biology is how can a single cell divide to produce two progeny cells that adopt different fates? We provided evidence of the significance of asymmetric division in human haematopoietic stem cells. RECENT FINDINGS By monitoring the symmetry of divisions of haematopoietic stem cells and following their subsequent developmental potentials at the single cell level, we established a relationship between divisional kinetics and self-renewal capacity. Direct cell-cell contact with cellular determinants in the niche has been shown to play an essential role in maintaining stemness. The creation of in-vitro models for the niche, such as human mesenchymal stromal cells, has provided a controlled laboratory environment in which the relative significance of chemokines and adhesion molecules can be studied. SUMMARY Identification of the molecular interactions between stem cells and their niche has led to an understanding of the mechanisms that control the self-renewal of stem cells. Ultimately, molecular signals triggered by adhesion and junction complexes are responsible for the adoption of specific cell fate.
Collapse
Affiliation(s)
- Anthony D Ho
- Department of Medicine V, University of Heidelberg, Heidelberg, Germany.
| | | |
Collapse
|
28
|
Glauche I, Cross M, Loeffler M, Roeder I. Lineage specification of hematopoietic stem cells: mathematical modeling and biological implications. Stem Cells 2007; 25:1791-9. [PMID: 17412891 DOI: 10.1634/stemcells.2007-0025] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Lineage specification of hematopoietic stem cells is considered a progressive restriction in lineage potential. This view is consistent with observations that differentiation and lineage specification is preceded by a low-level coexpression of lineage specific, potentially antagonistic genes in early progenitor cells. This coexistence, commonly referred to as priming, disappears in the course of differentiation when certain lineage-restricted genes are upregulated while others are downregulated. Based on this phenomenological description, we propose a quantitative model that describes lineage specification as a competition process between different interacting lineage propensities. The competition is governed by environmental stimuli promoting a drift from a multipotent coexpression to the dominance of one lineage. The assumption of a context-dependent intracellular differentiation control is consistently embedded into our previously proposed model of hematopoietic stem cell organization. The extended model, which comprises self-renewal and lineage specification, is verified using available data on the lineage specification potential of primary hematopoietic stem cells and on the differentiation kinetics of the FDCP-mix cell line. The model provides a number of experimentally testable predictions. From our results, we conclude that lineage specification is best described as a flexible and temporally extended process in which lineage commitment emerges as the result of a sequence of small decision steps. The proposed model provides a novel systems biological view on the functioning of lineage specification in adult tissue stem cells and its connections to the self-renewal properties of these cells. Disclosure of potential conflicts of interest is found at the end of this article.
Collapse
Affiliation(s)
- Ingmar Glauche
- Institute for Medical Informatics, Statistics and Epidemiology, University of Leipzig, Leipzig, Germany.
| | | | | | | |
Collapse
|
29
|
Yang HY, Kim SH, Kim SH, Kim DJ, Kim SU, Yu DY, Yeom YI, Lee DS, Kim YJ, Park BJ, Lee TH. The suppression of zfpm-1 accelerates the erythropoietic differentiation of human CD34+ cells. Biochem Biophys Res Commun 2006; 353:978-84. [PMID: 17207461 DOI: 10.1016/j.bbrc.2006.12.155] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2006] [Accepted: 12/17/2006] [Indexed: 11/24/2022]
Abstract
Erythropoiesis is a complex multistage process for the differentiation of mature erythrocytes from hematopoietic stem cells. The function of several transcription factors has been reported in hematopoietic stem cell differentiation. However, the molecular basis governing its functional behavior is unclear. In this study, we characterized the role of Zfpm-1 during the erythropoietic differentiation of human hematopoietic stem cells. To verify the function of Zfpm-1 during erythropoietic differentiation, we established human CD34+ cell culture system by using human umbilical cord blood. At day 7 of the human CD34+ cell differentiation process to proerythocytes, Zfpm-1 was initially up-regulated and then dramatically down-regulated at day 9. The Zfpm-1 siRNA transfected HSCs contained 20% more GPA+ cells than the mock transfected cells, and showed repressed expression of the hematopoietic transcription factors, c-myc and c-myb, but increased expression of GATA-1. In contrast, the Zfpm-1 gain-of-function is the opposite of loss-of-function results above.
Collapse
Affiliation(s)
- Hee-Young Yang
- Department of Molecular Medicine, Chonnam National University, Gwangju, Republic of Korea
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
30
|
Araki H, Yoshinaga K, Boccuni P, Zhao Y, Hoffman R, Mahmud N. Chromatin-modifying agents permit human hematopoietic stem cells to undergo multiple cell divisions while retaining their repopulating potential. Blood 2006; 109:3570-8. [PMID: 17185465 DOI: 10.1182/blood-2006-07-035287] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Abstract
Human hematopoietic stem cells (HSCs) exposed to cytokines in vitro rapidly divide and lose their characteristic functional properties presumably due to the alteration of a genetic program that determines the properties of an HSC. We have attempted to reverse the silencing of this HSC genetic program by the sequential treatment of human cord blood CD34+ cells with the chromatin-modifying agents, 5-aza-2′-deoxycytidine (5azaD) and trichostatin A (TSA). We determined that all CD34+CD90+ cells treated with 5azaD/TSA and cytokines after 9 days of incubation divide, but to a lesser degree than cells exposed to only cytokines. When CD34+CD90+ cells that have undergone extensive number of cell divisions (5-10) in the presence of cytokines alone were transplanted into immunodeficient mice, donor cell chimerism was not detectable. By contrast, 5azaD/TSA-treated cells that have undergone similar numbers of cell divisions retained their marrow repopulating potential. The expression of several genes and their products previously implicated in HSC self-renewal were up-regulated in the cells treated with 5azaD/TSA as compared to cells exposed to cytokines alone. These data indicate that HSC treated with chromatin-modifying agents are capable of undergoing repeated cell divisions in vitro while retaining their marrow-repopulating potential.
Collapse
Affiliation(s)
- Hiroto Araki
- Section of Hematology/Oncology, Department of Medicine, University of Illinois at Chicago, 909 S. Wolcott Avenue, Chicago, IL 60612, USA
| | | | | | | | | | | |
Collapse
|
31
|
Arata Y, Kouike H, Zhang Y, Herman MA, Okano H, Sawa H. Wnt signaling and a Hox protein cooperatively regulate psa-3/Meis to determine daughter cell fate after asymmetric cell division in C. elegans. Dev Cell 2006; 11:105-15. [PMID: 16824957 DOI: 10.1016/j.devcel.2006.04.020] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2005] [Revised: 03/14/2006] [Accepted: 04/11/2006] [Indexed: 12/20/2022]
Abstract
Asymmetric cell division is a mechanism for achieving cellular diversity. In C. elegans, many asymmetric cell divisions are controlled by the Wnt-MAPK pathway through POP-1/TCF. It is poorly understood, however, how POP-1 determines the specific fates of daughter cells. We found that nob-1/Hox, ceh-20/Pbx, and a Meis-related gene, psa-3, are required for asymmetric division of the T hypodermal cell. psa-3 expression was asymmetric between the T cell daughters, and it was regulated by POP-1 through a POP-1 binding site in the psa-3 gene. psa-3 expression was also regulated by NOB-1 and CEH-20 through a NOB-1 binding sequence in a psa-3 intron. PSA-3 can bind CEH-20 and function after the T cell division to promote the proper fate of the daughter cell. These results indicate that cooperation between Wnt signaling and a Hox protein functions to determine the specific fate of a daughter cell.
Collapse
Affiliation(s)
- Yukinobu Arata
- Laboratory for Cell Fate Decision, RIKEN, Center for Developmental Biology, Kobe 650-0047, Japan
| | | | | | | | | | | |
Collapse
|
32
|
Ricci C, Onida F, Ghidoni R. Sphingolipid players in the leukemia arena. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2006; 1758:2121-32. [PMID: 16904628 DOI: 10.1016/j.bbamem.2006.06.016] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2005] [Revised: 06/12/2006] [Accepted: 06/19/2006] [Indexed: 01/21/2023]
Abstract
Sphingolipids function as bioactive mediators of different cellular processes, mostly proliferation, survival, differentiation and apoptosis, besides being structural components of cellular membranes. Involvement of sphingolipid metabolism in cancerogenesis was demonstrated in solid tumors as well as in hematological malignancies. Herein, we describe the main biological and clinical aspects of leukemias and summarize data regarding sphingolipids as mediators of apoptosis triggered in response to anti-leukemic agents and synthetic analogs as inducers of cell death as well. We also report the contribution of molecules that modulate sphingolipid metabolism to development of encouraging strategies for leukemia treatment. Finally we address how deregulation of sphingolipid metabolism is associated to occurrence of therapy resistance both in vitro and in vivo. Sphingolipids can be considered promising therapeutic tools alone or in combination with other compounds, as well as valid targets in the attempt to eradicate leukemia and overcome drug resistance.
Collapse
Affiliation(s)
- Clara Ricci
- Laboratory of Biochemistry and Molecular Biology, San Paolo University Hospital, Medical School, University of Milan, 20142 via A. di Rudinì, 8-Milan, Italy
| | | | | |
Collapse
|
33
|
Murray PE, García-Godoy F. The outlook for implants and endodontics: a review of the tissue engineering strategies to create replacement teeth for patients. Dent Clin North Am 2006; 50:299-315, x. [PMID: 16530064 DOI: 10.1016/j.cden.2005.11.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Ideally, root canal therapy involves the removal of diseased pulp tissues and permanent replacement with healthy pulp to revitalize teeth. Rather than placing implants, the ideal solution is to grow new replacement teeth. Success rates of implants and endodontic treatments can exceed 90%, which presents a formidable challenge to tissue engineering researchers to ensure that future dental treatments are even more successful. The purpose of this article is to explain how tissue engineering can be used to create replacement teeth. The science of tissue engineering has evolved from growing simple tissues in cell culture incubators to a multistep process. Although the problems of introducing tissue engineering therapies as part of routine dental treatments are substantial, the potential benefits are equally ground breaking.
Collapse
Affiliation(s)
- Peter E Murray
- College of Dental Medicine, Nova Southeastern University, 3200 South University Drive, Fort Lauderdale, FL 33328, USA.
| | | |
Collapse
|
34
|
Araki H, Mahmud N, Milhem M, Nunez R, Xu M, Beam CA, Hoffman R. Expansion of human umbilical cord blood SCID-repopulating cells using chromatin-modifying agents. Exp Hematol 2006; 34:140-9. [PMID: 16459182 DOI: 10.1016/j.exphem.2005.10.002] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2005] [Revised: 10/13/2005] [Accepted: 10/13/2005] [Indexed: 11/29/2022]
Abstract
OBJECTIVE We investigated whether the addition of two chromatin-modifying agents, 5-aza-2'-deoxycytidine (5azaD) and trichostatin A (TSA), to cord blood (CB) CD34(+) cells in culture results in expansion of the numbers of severe combined immunodeficient (SCID) repopulating cells (SRC). MATERIALS AND METHODS Human CB CD34(+) cells were cultured with cytokines in the presence or absence of 5azaD/TSA. After 9 days of culture, the fold expansion of CD34(+) and CD34(+)CD90(+) cell numbers, colony-forming unit (CFU)-mix, cobblestone area-forming cell (CAFC), and SRC numbers were determined. RESULTS A 12.5-fold expansion of CD34(+)CD90(+) cells was observed in the 5azaD/TSA-treated cultures in comparison to the input cell numbers. Expansion of CD34(+)CD90(+) cells was associated with a 9.8-fold increase in the numbers of CFU-mix and 11.5-fold increase in CAFC. 5azaD/TSA treatment of the CB CD34(+) cells resulted in a 9.6-fold expansion of the absolute number of SRC following 9 days of culture as determined by limiting dilution analysis. Expansion of cells maintaining CD34(+)CD90(+) phenotype was not due to the retention of a quiescent population of cells because all of the CD34(+)CD90(+) cells in the culture had undergone cellular division. 5azaD/TSA-treated CD34(+)CD90(+) cells, but not CD34(+)CD90(-) cells were responsible for in vivo hematopoietic repopulation potential of nonobese diabetic/SCID mice. CONCLUSION Ex vivo expansion strategy using chromatin-modifying agents provides a potential avenue by which to expand the number of hematopoietic stem cells (HSC) with a single CB unit for use as an alternative source of HSC grafts for adult recipients.
Collapse
Affiliation(s)
- Hiroto Araki
- Section of Hematology/Oncology, Department of Medicine, University of Illinois at Chicago, 60607, USA
| | | | | | | | | | | | | |
Collapse
|
35
|
Abstract
Adult stem cells hold many promises for future clinical applications and regenerative medicine. The haematopoietic stem cell (HSC) is the best-characterized somatic stem cell so far, but in vitro expansion has been unsuccessful, limiting the future therapeutic potential of these cells. Here we review recent progress in characterizing the composition of the HSC bone-marrow microenvironment, known as the HSC niche. During homeostasis, HSCs, and therefore putative bone-marrow HSC niches, are located near bone surfaces or are associated with the sinusoidal endothelium. The molecular crosstalk between HSCs and the cellular constituents of these niches is thought to control the balance between HSC self-renewal and differentiation, indicating that future successful expansion of HSCs for therapeutic use will require three-dimensional reconstruction of a stem-cell-niche unit.
Collapse
Affiliation(s)
- Anne Wilson
- Ludwig Institute for Cancer Research, Lausanne Branch, University of Lausanne, Chemin des Boveresses 155, 1066 Epalinges, Switzerland
| | | |
Collapse
|
36
|
Giebel B, Zhang T, Beckmann J, Spanholtz J, Wernet P, Ho AD, Punzel M. Primitive human hematopoietic cells give rise to differentially specified daughter cells upon their initial cell division. Blood 2006; 107:2146-52. [PMID: 16249381 DOI: 10.1182/blood-2005-08-3139] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
It is often predicted that stem cells divide asymmetrically, creating a daughter cell that maintains the stem-cell capacity, and 1 daughter cell committed to differentiation. While asymmetric stem-cell divisions have been proven to occur in model organisms (eg, in Drosophila), it remains illusive whether primitive hematopoietic cells in mammals actually can divide asymmetrically. In our experiments we have challenged this question and analyzed the developmental capacity of separated offspring of primitive human hematopoietic cells at a single-cell level. We show for the first time that the vast majority of the most primitive, in vitro–detectable human hematopoietic cells give rise to daughter cells adopting different cell fates; 1 inheriting the developmental capacity of the mother cell, and 1 becoming more specified. In contrast, approximately half of the committed progenitor cells studied gave rise to daughter cells, both of which adopted the cell fate of their mother. Although our data are compatible with the model of asymmetric cell division, other mechanisms of cell fate specification are discussed. In addition, we describe a novel human hematopoietic progenitor cell that has the capacity to form natural killer (NK) cells as well as macrophages, but not cells of other myeloid lineages.
Collapse
Affiliation(s)
- Bernd Giebel
- Institute for Transplantation Diagnostics and Cell Therapeutics, Heinrich-Heine-University Düsseldorf, D-40225 Düsseldorf, Germany
| | | | | | | | | | | | | |
Collapse
|
37
|
Abstract
Hematopoietic stem cells (HSCs) balance self-renewal and differentiation in order to sustain lifelong blood production and simultaneously maintain the HSC pool. However, there is clear evidence that HSCs are subject to quantitative and qualitative exhaustion. In this review, we briefly discuss several known aspects of the stem cell aging process, including DNA damage, telomere shortening, and oxidative stress. Besides these known players, there is increasing evidence that higher order chromatin structure, largely defined by the histone code and affecting transcriptional activity, is important. A model is suggested which describes how epigenetic regulation of gene transcription by modulation of the chromatin structure in stem cells can account for regulation of the aging program.
Collapse
Affiliation(s)
- Leonie M Kamminga
- Department of Cell Biology, Section Stem Cell Biology, University Medical Center Groningen, University of Groningen, 9713 AV Groningen, The Netherlands
| | | |
Collapse
|
38
|
Ho AD, Wagner W. Bone marrow niche and leukemia. ERNST SCHERING FOUNDATION SYMPOSIUM PROCEEDINGS 2006:125-139. [PMID: 17939299 DOI: 10.1007/2789_2007_048] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Mounting evidence indicates that human cancers may originate from malignant transformation of stem cells. The most convincing proof is found in acute myeloid leukemia, where only a small subset of slowly dividing cells was able to induce transplantable acute myeloid leukemia. Normal hematopoietic stem cells (HSC) are characterized by their unlimited ability to self-renew, give rise to a multitude of cells that exhibit more differentiated features, and show slow division kinetics. Using human HSC and mesenchymal stromal cells (MSC) as models, we and others have demonstrated the vital role of the cellular niche in maintaining the self-renewing capacity, that is, "stemness" of HSC. Without direct contact with the cellular niche, HSC tend to differentiate and lose their stemness. Similar to their normal counterparts, leukemia stem cells divide slowly and maintain their self-renewal capacity through interaction with the niche. As a consequence, they are resistant to conventional chemotherapy strategies that target rapidly dividing cells. Thus it is of utmost importance to understand the interaction between cellular niche and normal HSC as well as between leukemia stem cells and the niche to provide a basis for more efficient treatment strategies.
Collapse
Affiliation(s)
- A D Ho
- Department of Medicine V, University of Heidelberg, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany.
| | | |
Collapse
|
39
|
Abstract
The blood-related cancer leukaemia was the first disease where human CSCs (cancer stem cells), or LSCs (leukaemic stem cells), were isolated. The haematopoietic system is one of the best tissues for investigating CSCs, since the developmental hierarchy of normal blood formation is well defined. Leukaemia can now be viewed as aberrant haematopoietic processes initiated by rare LSCs that have maintained or reacquired the capacity for indefinite proliferation through accumulated mutations and/or epigenetic changes. Yet, despite their critical importance, much remains to be learned about the developmental origin of LSCs and the mechanisms responsible for their emergence in the course of the disease. This report will review our current knowledge on LSC development and finally demonstrate how these discoveries provide a paradigm for identification of CSCs from solid tumours.
Collapse
|
40
|
Wagner W, Saffrich R, Wirkner U, Eckstein V, Blake J, Ansorge A, Schwager C, Wein F, Miesala K, Ansorge W, Ho AD. Hematopoietic Progenitor Cells and Cellular Microenvironment: Behavioral and Molecular Changes upon Interaction. Stem Cells 2005; 23:1180-91. [PMID: 15955826 DOI: 10.1634/stemcells.2004-0361] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Cell-cell contact between stem cells and cellular determinants of the microenvironment plays an essential role in controlling cell division. Using human hematopoietic progenitor cells (CD34+/CD38-) and a stroma cell line (AFT024) as a model, we have studied the initial behavioral and molecular sequel of this interaction. Time-lapse microscopy showed that CD34+/CD38- cells actively migrated toward and sought contact with stroma cells and 30% of them adhered firmly to AFT024 stroma through the uropod. CD44 and CD34 are colocalized at the site of contact. Gene expression profiles of CD34+/CD38- cells upon cultivation with or without stroma for 16, 20, 48, or 72 hours were analyzed using our human genome cDNA microarray. Chk1, egr1, and cxcl2 were among the first genes upregulated within 16 hours. Genes with the highest upregulation throughout the time course included tubulin genes, ezrin, c1qr1, fos, pcna, mcm6, ung, and dnmt1, genes that play an essential role in reorganization of the cytoskeleton system, stabilization of DNA, and methylation patterns. Our results demonstrate directed migration of CD34+/CD38- cells toward AFT024 and adhesion through the uropod and that upon interaction with supportive stroma, reorganization of the cytoskeleton system, regulation of cell division, and maintenance of genetic stability represent the most essential steps.
Collapse
Affiliation(s)
- Wolfgang Wagner
- Department of Medicine V, University of Heidelberg, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
41
|
Abstract
The blood-related cancer leukaemias were the first diseases where human cancer stem cells, or leukaemic stem cells (LSC), were isolated. The haematopoietic system is one of the best tissues for investigating cancer stem cells, because the developmental hierarchy of normal blood formation is well defined. Leukaemias can now be viewed as aberrant haematopoietic processes initiated by rare LSC that have maintained or reacquired the capacity for indefinite proliferation through accumulated mutations and/or epigenetic changes. Yet, despite their critical importance, much remains to be learned about the developmental origin of LSC and the mechanisms responsible for their emergence in the course of the disease. This report will review our current knowledge on normal and LSC development and examine the impact of these discoveries may have clinically and in our understanding of the leukaemogenic process.
Collapse
Affiliation(s)
- Dominique Bonnet
- Haematopoietic Stem Cell Laboratory, Cancer Research UK, London Research Institute, London, UK.
| |
Collapse
|
42
|
Abstract
Stem cell transplantation, whether autologous or allogeneic, improves the outcome of patients with a number of hematologic malignancies or solid tumors. A relevant proportion of these patients are excluded from this treatment because sufficient numbers of hematopoietic stem cells cannot be obtained by standard cytokine-assisted mobilization. In this article we review the physiology of peripheral blood progenitor cell (PBPC) mobilization and discuss the role of adhesion molecules, such as integrins and selectins, chemokines and their ligands, such as SDF-1alpha and CXCR4, and proteolytic enzymes. Based on this knowledge, several innovative pharmacologic approaches have been proposed to boost the stem cell harvest. Some of them (CTCE, C3a receptor agonist and GrobetaT) are still subject of pre-clinical development, others, such as chemokine receptor ligand AMD3100, have recently been introduced in clinical trials and already deliver promising results. It appears possible to harvest PBPC successfully in poor mobilizers and to cut down the number of collections required in the remaining PBPC donors.
Collapse
Affiliation(s)
- S Fruehauf
- Department of Internal Medicine V, University of Heidelberg, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany
| | | | | |
Collapse
|