scholarly journals A Novel Platform to Test In Vivo Single Gene Dependencies in t(8,21) and t(15,17) AML Confirms Zeb2 as Leukemia Target

Cancers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3768
Author(s):  
Giulia De Conti ◽  
Alicja M. Gruszka ◽  
Debora Valli ◽  
Andrea Umberto Cammarata ◽  
Matteo Righi ◽  
...  
Keyword(s):  
Transgenic Mice ◽  
Fluorescent Protein ◽  
Constitutive Expression ◽  
Model Systems ◽  
Leukemic Cells ◽  
Tamoxifen Treatment ◽  
Selection Marker ◽  
In Vivo Model ◽  
Hematopoietic Stem

The increased usage of high-throughput technologies in cancer research, including genetic and drug screens, generates large sets of candidate targets that need to be functionally validated for their roles in tumor development. Thus, reliable and robust in vivo model systems are needed to perform reverse genetic experiments. Ideally, these models should allow for a conditional silencing of the target and an unambiguous identification of engineered cancer cells. Here, we present a platform consisting of: (i) t(8;21) and t(15;17) driven acute myeloid leukemia (AML) transgenic mice with constitutive expression of green fluorescent protein (GFP) and inducible expression of Cre recombinase, and (ii) REX, a modified pSico lentiviral vector for inducible shRNA expression and red fluorescent protein (RFP) as a selection marker. In this system, leukemic cells from transgenic mice are transduced with REX, flow sorted, and transplanted into syngeneic hosts. Gene interference is induced in established tumors by tamoxifen treatment. Dual-color cell fluorescence guides the in vivo identification of shRNA interfered AML cells, monitoring engraftment and disease progression. We tested the platform by inducing knockdown of Zeb2, a gene upregulated by AML1-ETO and PML-RARα oncogenes in pre-leukemic hematopoietic stem cell compartment, and observed a significant delay in leukemia onset. This proves the power and utility of the platform and confirms Zeb2 contribution to the pathogenesis of AML.

Evidence for a positive role of SHIP in the BCR-ABL–mediated transformation of primitive murine hematopoietic cells and in human chronic myeloid leukemia

Blood ◽  
2003 ◽  
Vol 102 (8) ◽  
pp. 2976-2984 ◽  
Author(s):  
Xiaoyan Jiang ◽  
Matthew Stuible ◽  
Yves Chalandon ◽  
Andra Li ◽  
Wing Yiu Chan ◽  
...  
Keyword(s):  
Chronic Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Fluorescent Protein ◽  
Chronic Phase ◽  
Leukemic Cells ◽  
Mouse Bone Marrow ◽  
Positive Role ◽  
Hematopoietic Stem

Abstract Previous studies suggested that the SH2-containing inositol-5-phosphatase (SHIP) may play a tumor suppressor-like function in BCR-ABL–mediated leukemogenesis. To investigate this possibility, we first developed a new assay for quantitating transplantable multilineage leukemia-initiating cells (L-ICs) in hematopoietic stem cell (HSC)–enriched mouse bone marrow (BM) cells transduced with a BCR-ABL–GFP (green fluorescent protein) retrovirus. The frequency of L-ICs (1 of 430 Sca-1+lin– cells) was 7-fold lower than the frequency of HSCs in the Sca-1+lin– subset transduced with a control virus (1 of 65 cells). Forced BCRABL expression was also accompanied by a loss of regular HSC activity consistent with the acquisition of an increased probability of differentiation. Interestingly, the frequency and in vivo behavior of wild-type (+/+) and SHIP–/– L-ICs were indistinguishable, and in vitro, Sca-1+lin– BCR-ABL–transduced SHIP–/– cells showed a modestly reduced factor independence. Comparison of different populations of cells from patients with chronic myeloid leukemia (CML) in chronic phase and normal human BM showed that the reduced expression of full-length SHIP proteins seen in the more mature (CD34–lin+) leukemic cells is not mirrored in the more primitive (CD34+lin–) leukemic cells. Thus, SHIP expression appears to be differently altered in the early and late stages of differentiation of BCR-ABL–transformed cells, underscoring the importance of the cellular context in which its mechanistic effects are analyzed.

scholarly journals Development of an in vivo model to study clonal lineage relationships in hematopoietic cells using Brainbow2.1/Confetti mice

2019 ◽  
Vol 5 (10) ◽  
pp. FSO427 ◽  
Author(s):  
Jolanda JD de Roo ◽  
Sandra A Vloemans ◽  
Hans Vrolijk ◽  
Edwin FE de Haas ◽  
Frank JT Staal
Keyword(s):  
Fluorescent Protein ◽  
T Cell Development ◽  
Low Complexity ◽  
In Vivo Model ◽  
Special Focus ◽  
Hematopoietic Progenitor ◽  
Hematopoietic Stem ◽  
Cell Clones ◽  
Protein Cell

Hematopoietic stem cells maintain the homeostasis of all blood cell progeny during development and repopulation-demanding events. To study the lineage relationships during hematopoiesis, increasingly complex cell tracing models are being developed. In this study, we describe adaptations to the original R26R-Confetti mouse model, which subsequently offers a relatively easy approach to study low complexity clonality during hematopoiesis, with special focus on B and T lymphocyte development. This protocol employs spatiotemporal Cre expression controlled by gammaretroviral transduction for efficient fluorescent protein cell marking. Transplantation of fluorescently marked Lin- cKit+ hematopoietic progenitor cells into Rag1-/- mice, resulted in the visualization of differentially contributing stem cell clones to various lineages. Our methodology is useful to study questions in fundamental and preclinical hematopoietic research and in vivo B- and T-cell development.

scholarly journals In vivo transduction of primitive mobilized hematopoietic stem cells after intravenous injection of integrating adenovirus vectors

Blood ◽  
2016 ◽  
Vol 128 (18) ◽  
pp. 2206-2217 ◽  
Author(s):  
Maximilian Richter ◽  
Kamola Saydaminova ◽  
Roma Yumul ◽  
Rohini Krishnan ◽  
Jing Liu ◽  
...  
Keyword(s):  
Gene Therapy ◽  
Transgenic Mice ◽  
Fluorescent Protein ◽  
Ex Vivo ◽  
Genetically Modify ◽  
Blood Stream ◽  
Vector System ◽  
Hematopoietic Stem ◽  
Immunodeficient Mice

Abstract Current protocols for hematopoietic stem/progenitor cell (HSPC) gene therapy, involving the transplantation of ex vivo genetically modified HSPCs are complex and not without risk for the patient. We developed a new approach for in vivo HSPC transduction that does not require myeloablation and transplantation. It involves subcutaneous injections of granulocyte-colony-stimulating factor/AMD3100 to mobilize HSPCs from the bone marrow (BM) into the peripheral blood stream and the IV injection of an integrating, helper-dependent adenovirus (HD-Ad5/35++) vector system. These vectors target CD46, a receptor that is uniformly expressed on HSPCs. We demonstrated in human CD46 transgenic mice and immunodeficient mice with engrafted human CD34+ cells that HSPCs transduced in the periphery home back to the BM where they stably express the transgene. In hCD46 transgenic mice, we showed that our in vivo HSPC transduction approach allows for the stable transduction of primitive HSPCs. Twenty weeks after in vivo transduction, green fluorescent protein (GFP) marking in BM HSPCs (Lin−Sca1+Kit− cells) in most of the mice was in the range of 5% to 10%. The percentage of GFP-expressing primitive HSPCs capable of forming multilineage progenitor colonies (colony-forming units [CFUs]) increased from 4% of all CFUs at week 4 to 16% at week 12, indicating transduction and expansion of long-term surviving HSPCs. Our approach was well tolerated, did not result in significant transduction of nonhematopoietic tissues, and was not associated with genotoxicty. The ability to stably genetically modify HSPCs without the need of myeloablative conditioning is relevant for a broader clinical application of gene therapy.

The First Fully Experimental In Vivo Model of Human Leukemogenesis: Human Hematopoietic Stem Cells Infected with MLL-ENL Induce Pro-B Acute Lymphoblastic Leukemia in NOD/SCID Mice.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 238-238
Author(s):  
Frederic Barabe ◽  
James A. Kennedy ◽  
John E. Dick
Keyword(s):  
Bone Marrow ◽  
Acute Lymphoblastic Leukemia ◽  
Lymphoblastic Leukemia ◽  
Scid Mice ◽  
Leukemic Cells ◽  
In Vivo Model ◽  
Self Renewal ◽  
Genetic Event ◽  
Hematopoietic Stem

Abstract Identification of genes and translocations involved in human leukemia, as well as classification and clustering by gene arrays, have greatly evolved in the past years. However, the mechanisms of human leukemogenesis remain to be elucidated and the failure to develop an in vivo model where primary human hematopoietic cells are transformed into leukemic cells represents a significant limitation. Using a retrovirus encoding the oncogene MLL-ENL resulting from the t(11;19)(q23;p13.3) translocation found in acute myeloid leukemias (AML) as well as in acute lymphoblastic leukemias (ALL) of B or T cell origin, we infected lineage-negative cord blood cells and injected those cells into sub-lethally irradiated NOD/SCID mice. 15 to 20 weeks after injection, all the mice developed an aggressive pro-B acute lymphoblastic leukemia characterized by immature B cells (CD10+, CD19+, CD20−, IgD−, IgM−) involving more than 90% of bone marrow. Spleen and thymus were increased in size and infiltrated with >90% leukemic cells. Furthermore, analysis of the lungs and liver showed significant infiltration of these organs. Transplantation of leukemic cells from primary mice to secondary recipients was able to recapitulate the disease with the same phenotype and the same organ involvement in a shorter period of time. If MLL-ENL transduced cells are grown in suspension culture with IL-3 and SCF, there is massive proliferation of cells blocked in differentiation along the monocytic lineage. In contrast to untransduced cells, colony-forming progenitors were maintained long term in these cultures and could be serially replated, suggestive of an enhanced capacity for self-renewal. After 50 to 70 days in culture, these cells were injected in NOD/SCID mice and mice were analyzed after 12 to 15 weeks. Monoblastic cells were engrafted in the bone marrow and spleen with the same phenotype of the cultured cells (CD33+, CD11b+, CD15+, HLA DR+). These cells were able to engraft secondary and tertiary recipients formally demostrating increased self-renewal capacity of the transformed stem cell. In a limited number of primary mice, transplanted with high cell doses, AML developed at 15 weeks post-transplant. To our knowledge, these results provide the first in vivo model where human hematopietic stem/progenitor cells are transformed into leukemia. Remarkably, depending on the cellular environment, MLL-ENL can induce ALL or AML in primary cells as a sole genetic event, although we cannot rule out the spontaneous acquistion of additional co-operating genetic or epigenetic abnormalities. This model provides a significant step forward to understand the mechanisms involved in human leukemogenesis.

In Vitro and In Vivo Model Systems for the Study of Allergic and Inflammatory Disorders in Man

CHEST Journal ◽  
1985 ◽  
Vol 87 (5) ◽  
pp. 162S-164S ◽  
Author(s):  
Stephen P. Peters ◽  
Robert M. Naclerio ◽  
Alkis Togias ◽  
Robert P. Schleimer ◽  
Donald W. MacGlashan ◽  
...  
Keyword(s):  
Model Systems ◽  
In Vivo Model ◽  
Inflammatory Disorders

Live imaging of Runx1 expression in the dorsal aorta tracks the emergence of blood progenitors from endothelial cells

Blood ◽  
2010 ◽  
Vol 116 (6) ◽  
pp. 909-914 ◽  
Author(s):  
Enid Yi Ni Lam ◽  
Christopher J. Hall ◽  
Philip S. Crosier ◽  
Kathryn E. Crosier ◽  
Maria Vega Flores
Keyword(s):  
Endothelial Cells ◽  
Transcription Factor ◽  
Fluorescent Protein ◽  
Living Organism ◽  
Time Lapse ◽  
Dorsal Aorta ◽  
Transgenic Zebrafish ◽  
Hematopoietic Stem ◽  
Green Fluorescent

Abstract Blood cells of an adult vertebrate are continuously generated by hematopoietic stem cells (HSCs) that originate during embryonic life within the aorta-gonad-mesonephros region. There is now compelling in vivo evidence that HSCs are generated from aortic endothelial cells and that this process is critically regulated by the transcription factor Runx1. By time-lapse microscopy of Runx1-enhanced green fluorescent protein transgenic zebrafish embryos, we were able to capture a subset of cells within the ventral endothelium of the dorsal aorta, as they acquire hemogenic properties and directly emerge as presumptive HSCs. These nascent hematopoietic cells assume a rounded morphology, transiently occupy the subaortic space, and eventually enter the circulation via the caudal vein. Cell tracing showed that these cells subsequently populated the sites of definitive hematopoiesis (thymus and kidney), consistent with an HSC identity. HSC numbers depended on activity of the transcription factor Runx1, on blood flow, and on proper development of the dorsal aorta (features in common with mammals). This study captures the earliest events of the transition of endothelial cells to a hemogenic endothelium and demonstrates that embryonic hematopoietic progenitors directly differentiate from endothelial cells within a living organism.

scholarly journals The c-myc proto-oncogene regulates cardiac development in transgenic mice.

1990 ◽  
Vol 10 (7) ◽  
pp. 3709-3716 ◽  
Author(s):  
T Jackson ◽  
M F Allard ◽  
C M Sreenan ◽  
L K Doss ◽  
S P Bishop ◽  
...  
Keyword(s):  
Transgenic Mice ◽  
Mrna Expression ◽  
Cardiac Myocyte ◽  
Cellular Proliferation ◽  
Cardiac Development ◽  
Constitutive Expression ◽  
Transgenic Animals ◽  
Hypertrophic Growth ◽  
Myocyte Proliferation

During the maturation of the cardiac myocyte, a transition occurs from hyperplastic to hypertrophic growth. The factors that control this transition in the developing heart are unknown. Proto-oncogenes such as c-myc have been implicated in the regulation of cellular proliferation and differentiation, and in the heart the switch from myocyte proliferation to terminal differentiation is synchronous with a decrease in c-myc mRNA abundance. To determine whether c-myc can influence myocyte proliferation or differentiation, we examined the in vivo effect of increasing c-myc expression during embryogenesis and of preventing the decrease in c-myc mRNA expression that normally occurs during cardiac development. The model system used was a strain of transgenic mice exhibiting constitutive expression of c-myc mRNA in cardiac myocytes throughout development. In these transgenic mice, increased c-myc mRNA expression was found to be associated with both atrial and ventricular enlargement. This increase in cardiac mass was secondary to myocyte hyperplasia, with the transgenic hearts containing more than twice as many myocytes as did nontransgenic hearts. The results suggest that in the transgenic animals there is additional hyperplastic growth during fetal development. However, this additional proliferative growth is not reflected in abnormal myocyte maturation, as assessed by the expression of the cardiac and skeletal isoforms of alpha-actin. The results of this study indicate that constitutive expression of c-myc mRNA in the heart during development results in enhanced hyperplastic growth and suggest a regulatory role for this proto-oncogene in cardiac myogenesis.

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