scholarly journals Dose-dependent role of Gfi1 in murine hematopoietic stem cell self-renewal and differentiation

2019 ◽  
Author(s):  
Judith Schütte ◽  
Aniththa Thivakaran ◽  
Yahya Al-Matary ◽  
Pradeep Kumar Patnana ◽  
Daria Frank ◽  
...  
Keyword(s):  
Stem Cell ◽  
Myeloid Leukemia ◽  
Cell Types ◽  
Severe Neutropenia ◽  
Hematopoietic Stem ◽  
Lymphoid Lineage ◽  
Murine Hematopoietic Stem Cell ◽  
Dose Dependent ◽  
Poor Patient Survival

AbstractGfi1 (Growth factor independence 1) is a transcription factor that influences the stem cell capacity of hematopoietic stem cells (HSCs) as well as their differentiation into the myeloid and lymphoid lineage. Loss of Gfi1 impedes the repopulation capacity of HSCs and leads to a block in granulocyte generation causing severe neutropenia and monocytosis. Competitive transplantation assays showed that Gfi1-deficient cells were not able to reconstitute myeloid and lymphoid hematopoiesis in competition with Gfi1-wildtype (GFI1-36S) cells. Low Gfi1 levels (GFI1-knockdown = GFI1-KD) in blasts of myelodysplastic neoplasms, acute and chronic myeloid leukemia patients are associated with poor patient survival. To understand how reduced levels or loss of Gfi1 contribute to hematopoiesis, we analyzed the effect of GFI1-KD and Gfi1-KO on HSCs and more mature cell types in mice. GFI1-KD and Gfi1-KO led to strong decrease in HSC numbers, while the numbers of early progenitors (Lin− Sca1+cKit+ cells) were slightly increased. Competitive transplantation assays showed that GFI1-KD and Gfi1-KO HSCs can still engraft and expand, but they cannot contribute to myeloid and lymphoid differentiation.

scholarly journals Extreme disruption of heterochromatin is required for accelerated hematopoietic aging

Blood ◽  
2020 ◽  
Vol 135 (23) ◽  
pp. 2049-2058 ◽  
Author(s):  
Christine R. Keenan ◽  
Nadia Iannarella ◽  
Gaetano Naselli ◽  
Naiara G. Bediaga ◽  
Timothy M. Johanson ◽  
...  
Keyword(s):  
T Cells ◽  
Stem Cell ◽  
Hematopoietic Stem Cell ◽  
Cell Function ◽  
Cell Types ◽  
Premature Aging ◽  
Thymic Involution ◽  
Hematopoietic Stem ◽  
Hematopoietic System

Abstract Loss of heterochromatin has been proposed as a universal mechanism of aging across different species and cell types. However, a comprehensive analysis of hematopoietic changes caused by heterochromatin loss is lacking. Moreover, there is conflict in the literature around the role of the major heterochromatic histone methyltransferase Suv39h1 in the aging process. Here, we use individual and dual deletion of Suv39h1 and Suv39h2 enzymes to examine the causal role of heterochromatin loss in hematopoietic cell development. Loss of neither Suv39h1 nor Suv39h2 individually had any effect on hematopoietic stem cell function or the development of mature lymphoid or myeloid lineages. However, deletion of both enzymes resulted in characteristic changes associated with aging such as reduced hematopoietic stem cell function, thymic involution and decreased lymphoid output with a skewing toward myeloid development, and increased memory T cells at the expense of naive T cells. These cellular changes were accompanied by molecular changes consistent with aging, including alterations in nuclear shape and increased nucleolar size. Together, our results indicate that the hematopoietic system has a remarkable tolerance for major disruptions in chromatin structure and reveal a role for Suv39h2 in depositing sufficient H3K9me3 to protect the entire hematopoietic system from changes associated with premature aging.

scholarly journals CXCR4 Antagonists as Stem Cell Mobilizers and Therapy Sensitizers for Acute Myeloid Leukemia and Glioblastoma?

Biology ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 31 ◽  
Author(s):  
Vashendriya V.V. Hira ◽  
Cornelis J.F. Van Noorden ◽  
Remco J. Molenaar
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Acute Myeloid Leukemia ◽  
Stem Cell ◽  
Myeloid Leukemia ◽  
Patient Survival ◽  
Hematopoietic Stem ◽  
Poor Patient ◽  
Acute Myeloid ◽  
Poor Patient Survival

Glioblastoma is the most aggressive and malignant primary brain tumor in adults and has a poor patient survival of only 20 months after diagnosis. This poor patient survival is at least partly caused by glioblastoma stem cells (GSCs), which are slowly-dividing and therefore therapy-resistant. GSCs are localized in protective hypoxic peri-arteriolar niches where these aforementioned stemness properties are maintained. We previously showed that hypoxic peri-arteriolar GSC niches in human glioblastoma are functionally similar to hypoxic peri-arteriolar hematopoietic stem cell (HSC) niches in human bone marrow. GSCs and HSCs express the receptor C-X-C receptor type 4 (CXCR4), which binds to the chemoattractant stromal-derived factor-1α (SDF-1α), which is highly expressed in GSC niches in glioblastoma and HSC niches in bone marrow. This receptor–ligand interaction retains the GSCs/HSCs in their niches and thereby maintains their slowly-dividing state. In acute myeloid leukemia (AML), leukemic cells use the SDF-1α–CXCR4 interaction to migrate to HSC niches and become slowly-dividing and therapy-resistant leukemic stem cells (LSCs). In this communication, we aim to elucidate how disruption of the SDF-1α–CXCR4 interaction using the FDA-approved CXCR4 inhibitor plerixafor (AMD3100) may be used to force slowly-dividing cancer stem cells out of their niches in glioblastoma and AML. Ultimately, this strategy aims to induce GSC and LSC differentiation and their sensitization to therapy.

Role of Gene Mutations in Adult Acute Myeloid Leukemia Patients Receiving Allogeneic Hematopoietic Stem Cell Transplantation.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 3373-3373
Author(s):  
Sheng-Chieh Chou ◽  
Jih-Luh Tang ◽  
Liang-In Lin ◽  
Hsin-An Hou ◽  
Chien-Yuan Chen ◽  
...  
Keyword(s):  
Acute Myeloid Leukemia ◽  
Stem Cell ◽  
Myeloid Leukemia ◽  
Gene Mutations ◽  
Genetic Alterations ◽  
Prognostic Impact ◽  
Hematopoietic Stem ◽  
Wbc Count ◽  
Acute Myeloid

Abstract Abstract 3373 Poster Board III-261 Purpose Several gene mutations had been found to have clinical implications in patients with acute myeloid leukemia (AML), especially in those with normal karyotype. However, the role of such gene mutations for AML patients receiving allogeneic hematopoietic stem cell transplantation (allo-HSCT) was unclear and inconclusive. We retrospectively evaluated the prognostic impact of 8 gene mutations in adult AML patients undergoing allo-HSCT. Materials & Methods From 1995 to 2007, a total of 463 consecutive adult patients with de novo non-M3 AML had comprehensive gene mutation analyses at the National Taiwan University Hospital. Three hundred and twenty five patients who received conventional induction chemotherapy were enrolled in this study. Those who received only low dose chemotherapy or palliative treatment were excluded. The genetic alterations analyzed included NPM1, FLT3/ITD, FLT3/TKD, CEBPA, AML1/RUNX1, RAS, MLL/PTD, and WT1. The clinical implication of these genetic alterations in the patients receiving allo-HSCT was analyzed, and the result was compared with that in patients without allo-HSCT. Results The clinical characteristics in the patients receiving allo-HSCT (n=100) and those without (n=225) were similar with the exception of age, being younger in the former group (35.4 years vs. 49.5 years p<0.001). In univariate analysis, older age (Age > 45 years), higher initial WBC count (WBC>50K/μL), elevated LDH level, unfavorable karyotype, FLT3/ITD, mutations of AML1/RUNX1 were significantly associated with poorer overall survival (OS) in patients not receiving allo-HSCT; While NPM1mut/FLT3ITDneg and CEBPA mutations served as significantly good prognostic indicators. In multivariate analysis, age, WBC count, karyotype, FLT3/ITD, AML1/RUNX1, CEBPA and NPM1mut/FLT3ITDneg remained to be independent prognostic factors in non-allo-HSCT patients. However, in patients receiving allo-HSCT, only unfavorable karyotype and disease status (refractory or remission) at the time of transplantation were associated with poorer OS both in univariate and multivariate analyses. The similar prognostic impact of FLT3/ITD, CEBPA, AML1/RUNX1 and NPM1 on OS was not seen in patients receiving allo-HSCT. Furthermore, in contrast to its poor prognostic impact in non-allo-HSCT patients, mutation of AML1/RUNX1 was a significant good prognostic factor for relapse free survival (p=0.046), although not for OS, in allo-HSCT group. Conclusion FLT3/ITD, mutations of AML1/RUNX1, CEBPA and NPM1 have great prognostic implication for OS in AML patients not receiving allo-HSCT. However, their impact on OS is ameliorated in patients receiving allo-HSCT. The results need to be confirmed by further studies on more patients. Disclosures: No relevant conflicts of interest to declare.

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