scholarly journals N-RasG12D induces features of stepwise transformation in preleukemic human umbilical cord blood cultures expressing the AML1-ETO fusion gene

Blood ◽  
2011 ◽  
Vol 117 (7) ◽  
pp. 2237-2240 ◽  
Author(s):  
Fu-Sheng Chou ◽  
Mark Wunderlich ◽  
Andrea Griesinger ◽  
James C. Mulloy
Keyword(s):  
Myeloid Leukemia ◽  
Fusion Gene ◽  
Blood Cultures ◽  
Fusion Product ◽  
Human Umbilical Cord Blood ◽  
Human Umbilical Cord ◽  
Ras Mutation ◽  
Immunodeficient Mice ◽  
French American British ◽  
Cd34 Positivity

Abstract AML1-ETO (AE) is a fusion product of t(8;21) observed in 40% French-American-British M2 type of acute myeloid leukemia (AML). Clinical data suggest that Ras mutation is a frequent cooperating event in t(8;21) AML. Whether constitutively active Ras promotes leukemogenesis on the t(8;21) background has not been demonstrated experimentally. Here, we retrovirally expressed N-RasG12D in AE-expressing human hematopoieticcells to investigate cooperativity. The AE/N-RasG12D cultures were cytokine-independent, enriched for CD34 positivity, and possessed increased colony-forming and replating abilities. N-RasG12D expression led to Bcl-2 up-regulation and reduced apoptosis. Ectopic Bcl-2 expression also resulted in enhanced colony-forming and replating abilities but was insufficient to sustain cytokine independence. AE/N-RasG12D cells were more sensitive to Bcl-2 inhibition with ABT-737 than parent AE cells. Enhanced engraftment of AE/N-RasG12D cells was observed on intrafemoral injection into immunodeficient mice, presumably because of improved survival in the bone marrow microenvironment. N-RasG12D promotes progression toward transfor-mation in AE-expressing cells, partially through up-regulating Bcl-2.

scholarly journals The neurotransmitter receptor Gabbr1 regulates proliferation and function of hematopoietic stem and progenitor cells

Blood ◽  
2020 ◽  
Author(s):  
Lijian Shao ◽  
Adedamola Elujoba-Bridenstine ◽  
Katherine E Zink ◽  
Laura M Sanchez ◽  
Brian J Cox ◽  
...  
Keyword(s):  
Progenitor Cells ◽  
Ex Vivo ◽  
Human Umbilical Cord Blood ◽  
Human Umbilical Cord ◽  
Direct Role ◽  
Hematopoietic Stem ◽  
Knockout Mouse Model ◽  
Immunodeficient Mice ◽  
Bm Niche

Hematopoietic and nervous systems are linked via innervation of bone marrow (BM) niche cells. Hematopoietic stem/progenitor cells (HSPCs) express neurotransmitter receptors, such as the g-aminobutyric acid (GABA) type B receptor subunit 1 (GABBR1), suggesting that HSPCs could be directly regulated by neurotransmitters like GABA that directly bind to GABBR1. We performed imaging mass spectrometry (IMS) and found that endogenous GABA molecule is regionally localized and concentrated near the endosteum of the BM niche. To better understand the role of GABBR1 in regulating HSPCs, we generated a constitutive Gabbr1 knockout mouse model. Analysis revealed that HSPC numbers were significantly reduced in the BM compared to wild-type littermates. Moreover, Gabbr1 null hematopoietic stem cells (HSCs) had diminished capacity to reconstitute irradiated recipients in a competitive transplantation model. Gabbr1 null HSPCs were less proliferative under steady-state conditions and upon stress. Colony assays demonstrated that almost all Gabbr1 null HSPCs were in a slow or non-cycling state. In vitro differentiation of Gabbr1 null HSPCs in co-cultures, produced fewer overall cell numbers with significant defects in differentiation and expansion of the B cell lineage. To determine if GABBR1 agonist could stimulate human umbilical cord blood (UCB) HSPCs, we performed brief ex vivo treatment prior to transplant into immunodeficient mice, with significant increases in long-term engraftment of HSPCs compared to GABBR1 antagonist or vehicle treatments. Our results indicate a direct role for GABBR1 in HSPC proliferation, and identify a potential target to improve HSPC engraftment in clinical transplantation.

Constitutive Activation of Rac GTPases Is Induced by Cooperating Mutations in a Human Model of MLL-AF9 Leukemia.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 2959-2959
Author(s):  
Mark Wunderlich ◽  
Kevin A Link ◽  
Fu-Sheng Chou ◽  
James C. Mulloy
Keyword(s):  
Conflicts Of Interest ◽  
Therapeutic Potential ◽  
Culture Media ◽  
Human Model ◽  
Serum Starvation ◽  
Human Umbilical Cord Blood ◽  
Human Umbilical Cord ◽  
Immunodeficient Mice ◽  
Rac Gtpases

Abstract Abstract 2959 Poster Board II-935 Retroviral transduction of primary human umbilical cord blood CD34+ cells with a gene encoding MLL-AF9 (MA9) efficiently promotes immortalization in vitro and development of leukemia in a xenotransplant model. MA9 cells remain cytokine dependent with a strict requirement for Flt3 signaling. Additionally, the cells are hypersensitive to inhibition of the RAC GTPases. In this current study, we have examined a potential link between these pathways. We found that MA9 cells proliferate in culture media containing Flt3 Ligand (FL) as the sole cytokine, indicating that Flt3 signaling is sufficient for growth and survival. Furthermore, introduction of a mutant Flt3-ITD gene in these cells (MA9-ITD cells) not only promotes cytokine independent growth, but also significantly decreases leukemia latency in xenotransplant experiments. Consistent with the persistent requirement for active Rac signaling, we found that MA9 cells stimulated with FL induce the activated form of Rac (Rac-GTP) while MA9-ITD cells contain constitutively high levels of Rac-GTP, even after serum starvation and in the absence of all cytokines. Interestingly, we found that expression of the activated mutant NRas-G12D in MA9 cells (MA9-NRas cells) also leads to constitutive Rac activation, cytokine independent growth, and decreased leukemia latency upon transplantation into immunodeficient mice. Taken together, these results indicate that RAC activation may be a common integrating pathway by which secondary mutations cooperate in the progression towards leukemia. Consistent with this notion, both MA9-ITD and MA9-NRas cells remain sensitive to Rac inhibition with a small molecule Rac inhibitor or shRNA knockdown of Rac1 or Rac2. These data indicate that Rac signaling remains critical for MA9 survival and proliferation even in the context of additional mutations and highlights the therapeutic potential for targeting Rac. Disclosures: No relevant conflicts of interest to declare.

In vivo vasculogenic potential of human blood-derived endothelial progenitor cells

Blood ◽  
2007 ◽  
Vol 109 (11) ◽  
pp. 4761-4768 ◽  
Author(s):  
Juan M. Melero-Martin ◽  
Zia A. Khan ◽  
Arnaud Picard ◽  
Xiao Wu ◽  
Sailaja Paruchuri ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Progenitor Cells ◽  
Endothelial Progenitor Cells ◽  
Umbilical Vein ◽  
Human Umbilical Cord Blood ◽  
Human Umbilical Cord ◽  
Vascular Networks ◽  
Endothelial Progenitor ◽  
Immunodeficient Mice

Abstract Vascularization of tissues is a major challenge of tissue engineering (TE). We hypothesize that blood-derived endothelial progenitor cells (EPCs) have the required proliferative and vasculogenic activity to create vascular networks in vivo. To test this, EPCs isolated from human umbilical cord blood or from adult peripheral blood, and human saphenous vein smooth muscle cells (HSVSMCs) as a source of perivascular cells, were combined in Matrigel and implanted subcutaneously into immunodeficient mice. Evaluation of implants at one week revealed an extensive network of human-specific lumenal structures containing erythrocytes, indicating formation of functional anastomoses with the host vasculature. Quantitative analyses showed the microvessel density was significantly superior to that generated by human dermal microvascular endothelial cells (HDMECs) but similar to that generated by human umbilical vein endothelial cells (HUVECs). We also found that as EPCs were expanded in culture, their morphology, growth kinetics, and proliferative responses toward angiogenic factors progressively resembled those of HDMECs, indicating a process of in vitro maturation. This maturation correlated with a decrease in the degree of vascularization in vivo, which could be compensated for by increasing the number of EPCs seeded into the implants. Our findings strongly support the use of human EPCs to form vascular networks in engineered organs and tissues.

THE CASE VARIANT TRANSLOCATION T(3;9;22)(P24;Q34;Q11) IN CHRONIC MYELOID LEUKEMIA

2018 ◽  
Vol 64 (6) ◽  
pp. 810-814
Author(s):  
Kodirzhon Boboev ◽  
Yuliana Assesorova ◽  
Kh. Karimov ◽  
B. Allanazarova
Keyword(s):  
Adverse Effect ◽  
Chronic Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Fusion Gene ◽  
Genetic Locus ◽  
Philadelphia Chromosome ◽  
Chromosome 9 ◽  
Banding Technique ◽  
Variant Translocation

This paper presents a case of chronic myeloid leukemia with an earlier unknown variant translocation t (3; 9; 22) (p24; q34; q11) detected by cytogenetic research using the GTG-banding technique. Despite the absence of the classical Philadelphia chromosome, the presence of chromosome 9 and 22 derivatives, as well as the BCR-ABL fusion gene, allow this translocation to be considered pathogenetic for CML. A good response of the patient to the treatment with glivec is that there is no adverse effect on the pathogenesis of the disease of an additional genetic locus (3p24) involved in complex restructuring.

Therapeutic Potential of Endothelial Colony Forming Cells Derived from Human Umbilical Cord Blood

2019 ◽  
Vol 14 (6) ◽  
pp. 460-465 ◽  
Author(s):  
Jing Jia ◽  
Baitao Ma ◽  
Shaoshuai Wang ◽  
Ling Feng
Keyword(s):  
Cord Blood ◽  
Umbilical Cord ◽  
Tissue Regeneration ◽  
Umbilical Cord Blood ◽  
Therapeutic Potential ◽  
Human Umbilical Cord Blood ◽  
Proliferative Potential ◽  
Human Umbilical Cord ◽  
Preclinical Studies ◽  
Endothelial Colony Forming Cells

Endothelial progenitor cells (EPCs) are implicated in multiple biologic processes such as vascular homeostasis, neovascularization and tissue regeneration, and tumor angiogenesis. A subtype of EPCs is referred to as endothelial colony-forming cells (ECFCs), which display robust clonal proliferative potential and can form durable and functional blood vessels in animal models. In this review, we provide a brief overview of EPCs’ characteristics, classification and origins, a summary of the progress in preclinical studies with regard to the therapeutic potential of human umbilical cord blood derived ECFCs (CB-ECFCs) for ischemia repair, tissue engineering and tumor, and highlight the necessity to select high proliferative CB-ECFCs and to optimize their recovery and expansion conditions.

Effect of Dasatinib on Genes Related to Mitotic Catastrophe Pathway in Chronic Myeloid Leukemia Cells

2020 ◽  
Vol 20 ◽  
Author(s):  
Sezgi Kipcak ◽  
Buket Ozel ◽  
Cigir B. Avci ◽  
Leila S. Takanlou ◽  
Maryam S. Takanlou ◽  
...  
Keyword(s):  
Chronic Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Kinase Inhibitors ◽  
Fusion Gene ◽  
Philadelphia Chromosome ◽  
K562 Cells ◽  
Mitotic Catastrophe ◽  
Control Group ◽  
Cancer Therapies ◽  
Apoptosis Pathways

Background: Chronic myeloid leukemia (CML), is characterized by a reciprocal translocation t(9;22) and forms the BCR/ABL1 fusion gene, which is called the Philadelphia chromosome. The therapeutic targets for CML patients which are mediated with BCR/ABL1 oncogenic are tyrosine kinase inhibitors such as imatinib, dasatinib, and nilotinib. The latter two of which have been approved for the treatment of imatinib-resistant or intolerance CML patients. Mitotic catastrophe (MC) is one of the non-apoptotic mechanisms which frequently initiated in types of cancer cells in response to anti-cancer therapies; pharmacological inhibitors of G2 checkpoint members or genetic suppression of PLK1, PLK2, ATR, ATM, CHK1, and CHK2 can trigger DNA-damage-stimulated mitotic catastrophe. PLK1, AURKA/B anomalously expressed in CML cells, that phosphorylation and activation of PLK1 occur by AURKB at centromeres and kinetochores. Objective: The purpose of this study was to investigate the effect of dasatinib on the expression of genes in MC and apoptosis pathways in K562 cells. Methods: Total RNA was isolated from K-562 cells treated with the IC50 value of dasatinib and untreated cells as a control group. The expression of MC and apoptosis-related genes were analyzed by the qRT-PCR system. Results: The array-data demonstrated that dasatinib-treated K562 cells significantly caused the decrease of several genes (AURKA, AURKB, PLK, CHEK1, MYC, XPC, BCL2, and XRCC2). Conclusion: The evidence supply a basis to support clinical researches for the suppression of oncogenes such as PLKs with AURKs in the treatment of types of cancer especially chronic myeloid leukemia.

scholarly journals Programmed cell death 4 and BCR-ABL fusion gene expression are negatively correlated in chronic myeloid leukemia

2016 ◽  
Vol 12 (4) ◽  
pp. 2976-2981 ◽  
Author(s):  
Xia Zhang ◽  
Riming Liu ◽  
Baohua Huang ◽  
Xiaolu Zhang ◽  
Weijuan Yu ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cell Death ◽  
Chronic Myeloid Leukemia ◽  
Programmed Cell Death ◽  
Myeloid Leukemia ◽  
Fusion Gene ◽  
Programmed Cell Death 4

Hoechst dye efflux reveals a novel CD7+CD34− lymphoid progenitor in human umbilical cord blood

Blood ◽  
2000 ◽  
Vol 96 (6) ◽  
pp. 2125-2133 ◽  
Author(s):  
Robert W. Storms ◽  
Margaret A. Goodell ◽  
Alan Fisher ◽  
Richard C. Mulligan ◽  
Clay Smith
Keyword(s):  
Stem Cells ◽  
Cord Blood ◽  
Umbilical Cord ◽  
Umbilical Cord Blood ◽  
Large Population ◽  
Lymphoid Cells ◽  
Human Umbilical Cord Blood ◽  
Human Umbilical Cord ◽  
Hematopoietic Stem ◽  
Cd34 Cells

Abstract A novel Hoechst 33342 dye efflux assay was recently developed that identifies a population of hematopoietic cells termed side population (SP) cells. In the bone marrow of multiple species, including mice and primates, the SP is composed primarily of CD34−cells, yet has many of the functional properties of hematopoietic stem cells (HSCs). This report characterizes SP cells from human umbilical cord blood (UCB). The SP in unfractionated UCB was enriched for CD34+ cells but also contained a large population of CD34− cells, many of which were mature lymphocytes. SP cells isolated from UCB that had been depleted of lineage-committed cells (Lin− UCB) contained CD34+ and CD34− cells in approximately equivalent proportions. Similar to previous descriptions of human HSCs, the CD34+Lin− SP cells were CD38dimHLA-DRdimThy-1dimCD45RA−CD71−and were enriched for myelo-erythroid precursors. In contrast, the CD34−Lin− SP cells were CD38−HLA-DR−Thy-1−CD71−and failed to generate myelo-erythroid progeny in vitro. The majority of these cells were CD7+CD11b+CD45RA+, as might be expected of early lymphoid cells, but did not express other lymphoid markers. The CD7+CD34−Lin− UCB SP cells did not proliferate in simple suspension cultures but did differentiate into natural killer cells when cultured on stroma with various cytokines. In conclusion, the human Lin− UCB SP contains both CD34+ multipotential stem cells and a novel CD7+CD34−Lin− lymphoid progenitor. This observation adds to the growing body of evidence that CD34− progenitors exist in humans.

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