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1.
Interferon regulatory factor 4 (IRF-4) is essential for B and T cell development and immune response regulation, and has both nuclear and cytoplasmic functions. IRF-4 was originally identified as a proto-oncogene resulting from a t(6;14) chromosomal translocation in multiple myeloma and its expression was shown to be essential for multiple myeloma cell survival. However, we have previously shown that IRF-4 functions as a tumor suppressor in the myeloid lineage and in early stages of B cell development. In this study, we found that IRF-4 suppresses BCR/ABL transformation of myeloid cells. To gain insight into the molecular pathways that mediate IRF-4 tumor suppressor function, we performed a structure-function analysis of IRF-4 as a suppressor of BCR/ABL transformation. We found that the DNA binding domain deletion mutant of IRF-4, which is localized only in the cytoplasm, is still able to inhibit BCR/ABL transformation of myeloid cells. IRF-4 also functions as a tumor suppressor in bone marrow cells deficient in MyD88, an IRF-4-interacting protein found in the cytoplasm. However, IRF-4 tumor suppressor activity is lost in IRF association domain (IAD) deletion mutants. These results demonstrate that IRF-4 suppresses BCR/ABL transformation by a novel cytoplasmic function involving its IAD domain. 相似文献
2.
BCR sequences essential for transformation by the BCR-ABL oncogene bind to the ABL SH2 regulatory domain in a non-phosphotyrosine-dependent manner. 总被引:40,自引:0,他引:40
BCR-ABL is a chimeric oncogene implicated in the pathogenesis of Philadelphia chromosome-positive human leukemias. BCR first exon sequences specifically activate the tyrosine kinase and transforming potential of BCR-ABL. We have tested the hypothesis that activation of BCR-ABL may involve direct interaction between BCR sequences and the tyrosine kinase regulatory domains of ABL. Full-length c-BCR as well as BCR sequences retained in BCR-ABL bind specifically to the SH2 domain of ABL. The binding domain has been localized within the first exon of BCR and consists of at least two SH2-binding sites. This domain is essential for BCR-ABL-mediated transformation. Phosphoserine/phosphothreonine but not phosphotyrosine residues on BCR are required for interaction with the ABL SH2 domain. These findings extend the range of potential SH2-protein interactions in growth control pathways and suggest a function for SH2 domains in the activation of the BCR-ABL oncogene as well as a role for BCR in cellular signaling pathways. 相似文献
3.
Early pre-B-cell transformation induced by the v-fms oncogene in long-term mouse bone marrow cultures.
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Murine long-term bone marrow cultures that support B-lymphoid-cell development were infected with a helper-free retrovirus containing the v-fms oncogene. Infection of B-lymphoid cultures resulted in the rapid clonal outgrowth of early pre-B cells, which grew to high cell densities on stromal cell feeder layers, expressed v-fms-coded glycoproteins, and underwent immunoglobulin heavy-chain gene rearrangements. Late-passage cultures gave rise to factor-independent variants that proliferated in the absence of feeder layers, developed resistance to hydrocortisone, and became tumorigenic in syngeneic mice. The v-fms oncogene therefore recapitulates known effects of the v-abl and bcr-abl oncogenes on B-lineage cells. The ability of v-fms to induce transformation of early pre-B cells in vitro underscores the capacity of oncogenic mutants of the colony-stimulating factor-1 receptor to function outside the mononuclear phagocyte lineage. 相似文献
4.
Motiwala T Majumder S Ghoshal K Kutay H Datta J Roy S Lucas DM Jacob ST 《The Journal of biological chemistry》2009,284(1):455-464
Chronic myelogenous leukemia is typified by constitutive activation of the c-abl kinase as a result of its fusion to the breakpoint cluster region (BCR). Because the truncated isoform of protein-tyrosine phosphatase receptor-type O (PTPROt) is specifically expressed in hematopoietic cells, we tested the possibility that it could potentially dephosphorylate and inactivate the fusion protein bcr/abl. Ectopic expression of PTPROt in the chronic myelogenous leukemia cell line K562 indeed resulted in hypophosphorylation of bcr/abl and reduced phosphorylation of its downstream targets CrkL and Stat5, confirming that PTPROt could inactivate the function of bcr/abl. Furthermore, the expression of catalytically active PTPROt in K562 cells caused reduced proliferation, delayed transition from G0/G1 to S phase, loss of anchorage independent growth, inhibition of ex vivo tumor growth, and increased their susceptibility to apoptosis, affirming that this tyrosine phosphatase can revert the transformation potential of bcr/abl. Additionally, the catalytically inactive PTPROt acted as a trapping mutant that was also able to inhibit anchorage independence and facilitate apoptosis of K562 cells. The inhibitory action of PTPROt on bcr/abl was also confirmed in a murine myeloid cell line overexpressing bcr/abl. PTPROt expression was suppressed in K562 cells and was relieved upon treatment of the cells with 5-azacytidine, an inhibitor of DNA methyltransferase, with concomitant hypomethylation of the PTPRO CpG island. These data demonstrate that suppression of PTPROt by promoter methylation could contribute to the augmented phosphorylation and constitutive activity of its substrate bcr/abl and provide a potentially significant molecular therapeutic target for bcr/abl-positive leukemia. 相似文献
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6.
Hemopoiesis in long-term stroma-dependent cultures from lymphoid tissue: Production of cells with myeloid/dendritic characteristics 总被引:3,自引:0,他引:3
Summary A long-term stroma-dependent culture system (LTC) has been developed which continuously produces hemopoietic cells providing
an in vitro system for the study of cell differentiation. These nonadherent cell populations contain a large subpopulation of dendritic
cells (DC). LTC producing DC were easily generated from spleen, but could also be established from bone marrow (BM) and lymph
node with less success. It was difficult to establish DC-producing LTC from thymus. The properties of splenic and thymic stroma
have been compared. Spleen stroma developed more complicated networks of fibroblasts, endothelial cells, macrophages, and
DC. Thymic stromal monolayers were dominated by epithelial cells and fibroblasts, with a lower proportion of macrophages and
endothelial cells. They had a relatively sparse structure of cell networks compared with spleen stroma. Cells with dendritiform
morphology first appeared in cultures by 2–3 wk. The majority of cells produced were large cells which expressed DC-specific
cell surface markers, major histocompatibility complex (MHC) Class II molecules, and the CD80/CD86(B7) costimulator. A high
proportion of cells also expressed myeloid cell markers. No T or B lymphoid cells or granulocytes were present in the cultures.
LTC continued to produce nonadherent cells resembling myeloid/DC for long periods, even after passage of stromal cells and
stem cells at about 3–4 mo. after culture establishment. The LTC system offers potential to study the in vitro differentiation of myeloid/DC. 相似文献
7.
The Src family kinase Hck couples BCR/ABL to STAT5 activation in myeloid leukemia cells 总被引:16,自引:0,他引:16
Klejman A Schreiner SJ Nieborowska-Skorska M Slupianek A Wilson M Smithgall TE Skorski T 《The EMBO journal》2002,21(21):5766-5774
8.
Klymenko SV Misharina ZhA Abramenko IV Bilous NI Bebeshko VH 《T?Sitologii?a i genetika》2005,39(6):55-59
We report the results of BCR/ABL translocation analysis on interphase leukemic cells of 33 acute myeloid leukemia (AML) patients by fluorescence in situ hybridization. Of these, there were 13 persons exposed to ionizing radiation due to the Chernobyl accident with radiation-associated AML and 20 patients with spontaneous disease. BCR/ABL translocation which was detected in 4 and I case respectively may play an important role in radiation-induced leukemigenesis. 相似文献
9.
Bakshi SR Brahmbhatt MM Trivedi PJ Shukla SN Shah PM 《Journal of the Association of Genetic Technologists》2006,32(4):164-167
The Philadelphia (Ph) chromosome, a hallmark chromosomal anomaly observed in 95 percent of chronic myeloid leukemia (CML) cases, is known to involve the Abelson (ABL) proto-oncogene on chromosome 9 and the breakpoint cluster region (BCR) gene on chromosome 22, producing BCR/ABL mRNA encoding an abnormal tyrosine kinase protein. In the process of generating BCR-ABL fusion, the deletion of residual BCR or ABL occurs in 15-30 percent of CML patients. In addition, some rearrangements are complex, and do not yield the ABL/BCR fusion due to the involvement of a third chromosome in the rearrangement. The possible role of these deletions and complex rearrangements in disease outcome is an ongoing topic of research. We report our results of cytogenetic analysis with GTG banding and fluorescence in situ hybridization using dual color dual fusion probe (D-FISH) from Vysis Inc, USA in 169 (109 male and 60 female) CML patients registered at The Gujarat Cancer and Research Institute (GC and RI) from April 2004 to December 2005. GTG banding was carried out in 123 cases having analyzable metaphases. Of these 123 cases, D-FISH revealed atypical signal patterns in 57 patients (46%), and 12 cases revealed additional complex translocations indicative of disease progression. Out of 57 cases with atypical FISH patterns, 22 included metaphase FISH results, and the rest had only interphase FISH performed. In addition to the hallmark Philadelphia chromosome, other chromosomal aberrations in CML revealed heterogeneity of molecular events. Pooling of more data may lead to identification of new CML sub-groups and hence help in the analysis of clinical trials. Patients enrolled in our prospective study of prognostic significance will be followed up for disease free and overall survival in correlation with ABL-BCR deletion status. 相似文献
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11.
The 5' noncoding region of the human leukemia-associated oncogene BCR/ABL is a potent inhibitor of in vitro translation. 总被引:6,自引:1,他引:6
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The mRNA encoding the chimeric BCR/ABL oncogene, which is transcribed from the Philadelphia chromosome in human chronic myelogenous leukemia, has a 5' noncoding sequence greater than 500 bases in length which is highly GC rich and contains a short open reading frame. This untranslated sequence has a dramatic inhibitory effect upon translational efficiency in vitro. However, when BCR/ABL message is expressed in certain cell types such as the NIH 3T3 cell line, the 5' noncoding region has little inhibitory effect on translational efficiency. 相似文献
12.
Transformation of hematopoietic cells by BCR/ABL requires activation of a PI-3k/Akt-dependent pathway. 总被引:33,自引:2,他引:33
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T Skorski A Bellacosa M Nieborowska-Skorska M Majewski R Martinez J K Choi R Trotta P Wlodarski D Perrotti T O Chan M A Wasik P N Tsichlis B Calabretta 《The EMBO journal》1997,16(20):6151-6161
13.
Jingjing Xie Xiaoli Chen Junke Zheng Chunling Li Satomi Stacy Martin Holzenberger Xuemei Hu Cheng Cheng Zhang 《Journal of hematology & oncology》2015,8(1)
Background
The tyrosine kinase receptor insulin-like growth factor 1 receptor (IGF-IR) contributes to the initiation and progression of many types of malignancies. We previously showed that IGF-2, which binds IGF-IR, is an extrinsic factor that supports the ex vivo expansion of hematopoietic stem cells (HSCs). We also demonstrated that IGF-IR is not required for HSC activity in vivo.Methods and results
Here we investigated the role of IGF-IR in chronic myeloid leukemia (CML) using the retroviral BCR/ABL transplantation mouse model. Existing antibodies against IGF-IR are not suitable for flow cytometry; therefore, we generated a fusion of the human IgG Fc fragment with mutant IGF-2 that can bind to IGF-IR. We used this fusion protein to evaluate mouse primary hematopoietic populations. Through transplantation assays with IGF-IR+ and IGF-IR− cells, we demonstrated that IGF-IR is expressed on all mouse HSCs. The expression of IGF-IR is much higher on CML cells than on acute lymphoblastic leukemia (ALL) cells. The depletion of IGF-IR expression in BCR/ABL+ cells led to the development of ALL (mostly T cell ALL) but not CML. Lack of IGF-IR resulted in decreased self-renewal of the BCR/ABL+ CML cells in the serial replating assay.Conclusion
IGF-IR regulates the cell fate determination of BCR/ABL+ leukemia cells and supports the self-renewal of CML cells. 相似文献14.
R. A. Phillips 《Journal of cellular biochemistry》1980,14(1):77-83
Mature, functional lymphocytes rapidly disappear from long-term cultures of mouse bone marrow cells and never reappear. One reason for the loss of B lymphocytes is that the optimal culture conditions for maintenance of myeloid stem cells are suboptimal for lymphocyte survival. However, despite the absence of functional lymphocytes, stem cells from such cultures retain the ability to reconstitute irradiated mice with mitogen-responsive B and T lymphocytes. In fact, in vitro grown stem cells repopulate the lymphoid system better than the myeloid system; the defective myeloid potential does not result from the absence in the cultures of Thy–1 bearing regulatory cells (TSRC). Although the cultures lack mature lymphocytes, they contain putative T cell precursors detectable with an in vitro colony-forming assay (CFU-T). In vitro maintenance of CFU-T requires an appropriate adherent monolayer. Monolyaters from congenitally anemic mice of genotype S1/S1d fail to support either myeloid precursors or CFU-T. 相似文献
15.
T Otsuka R K Humphries D E Hogge A C Eaves C J Eaves 《Journal of cellular physiology》1991,148(3):370-379
Human hematopoietic cells can be maintained in vitro for many weeks in the absence of exogenously provided hematopoietic growth factors if an adequate stromal cell containing adherent layer is present. We have now extended the use of this type of long-term culture (LTC) system to create a model of perturbed hematopoiesis in which human tumor cells that constitutively produce a variety of factors are co-cultured together with normal human marrow cells. In the present study, we used the human bladder carcinoma cell line (5637) because these cells were known to produce not only a variety of factors active directly on hematopoietic cells but also factors that can stimulate hematopoietic growth factor production by human marrow stromal cells. Analysis of mRNA extracted from the adherent layer and measurement of growth factor bioactivity in the medium of established LTC of human marrow containing irradiated 5637 cells, showed increased levels of interleukin-1 and -6, as well as granulocyte and granulocyte-macrophage colony-stimulating factor production by comparison to control cultures. As in normal cultures, high proliferative potential clonogenic hematopoietic cells were found almost exclusively in the adherent layer of these co-cultures, but these primitive cells were maintained in a state of continuous turnover, in contrast to control cultures where the same cell types showed the expected oscillation between a quiescent and a proliferating state following each weekly change of the medium. A similar perturbation of primitive progenitor cycling was achieved by adding medium conditioned by 5637 cells twice a week to otherwise normal LTC. The presence of irradiated 5637 cells in the LTC or the addition of 5637 conditioned medium also resulted in modest (2- to 3-fold) but sustained increases in the total hematopoietic progenitor population, as well as in the final output of terminally differentiated granulocytes and macrophages. These findings indicate that primitive hematopoietic cells in LTC can be kept in a state of continuous activation for many weeks by appropriate endogenous or exogenous hematopoietic growth factor provision and that this does not necessarily lead either to their rapid exhaustion or to a large amplification in output of mature progeny. 相似文献
16.
BCR/ABL modifies the kinetics and fidelity of DNA double-strand breaks repair in hematopoietic cells
The oncogenic BCR/ABL tyrosine kinase facilitates the repair of DNA double-strand breaks (DSBs). We find that after gamma-irradiation BCR/ABL-positive leukemia cells accumulate more DSBs in comparison to normal cells. These lesions are efficiently repaired in a time-dependent fashion by BCR/ABL-stimulated non-homologous end-joining (NHEJ) followed by homologous recombination repair (HRR) mechanisms. However, mutations and large deletions were detected in HRR and NHEJ products, respectively, in BCR/ABL-positive leukemia cells. We propose that unfaithful repair of DSBs may contribute to genomic instability in the Philadelphia chromosome-positive leukemias. 相似文献
17.
Tyrosine phosphorylation of p95Vav in myeloid cells is regulated by GM-CSF, IL-3 and steel factor and is constitutively increased by p210BCR/ABL. 总被引:3,自引:0,他引:3
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Vav is a recently described proto-oncogene expressed only in hematopoietic cells which contains an SH2 and two SH3 domains and shares homology with the Dbl GDP-GTP exchange factor and BCR. p95Vav is phosphorylated on tyrosine residues in response to stimulation of the T cell antigen receptor, cross-linking of IgE or IgM receptors and stimulation of immature hematopoietic cells by Steel factor. Monoclonal antibodies to human Vav were generated and used to examine the events which regulate tyrosine phosphorylation of p95Vav in myeloid cells. In the factor-dependent MO7e cell line, p95Vav was rapidly phosphorylated on tyrosine residues in a dose- and time-dependent manner by GM-CSF, IL-3 and Steel factor. Introduction of the BCR/ABL oncogene into this cell line resulted in factor-independent proliferation and constitutive phosphorylation of p95Vav. Tyrosine phosphorylation of p95Vav was also substantially increased by treatment of cytokine-deprived cells with the tyrosine phosphatase inhibitor sodium vanadate. Since many of the cytokines known to induce tyrosine phosphorylation of p95Vav are also known to activate JAK family tyrosine kinases, we looked for an interaction of p95Vav with JAK kinases. p95Vav co-precipitated with JAK2 in MO7e cells stimulated with GM-CSF, but not in unstimulated cells. Also, JAK2 was found to be constitutively associated with p95Vav in vivo when expressed at high levels in insect cells using baculovirus vectors. A fusion protein consisting of glutathione-S-transferase and the SH2 domain of p95Vav (GST-Vav-SH2) precipitated JAK2, suggesting that this interaction is mediated by the SH2 domain of p95Vav.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
18.
19.
The BCR/ABL tyrosine kinase induces production of reactive oxygen species in hematopoietic cells 总被引:18,自引:0,他引:18
Sattler M Verma S Shrikhande G Byrne CH Pride YB Winkler T Greenfield EA Salgia R Griffin JD 《The Journal of biological chemistry》2000,275(32):24273-24278
The BCR/ABL oncogene causes chronic myelogenous leukemia, a myeloproliferative disorder characterized by clonal expansion of hematopoietic progenitor cells and myeloid cells. It is shown here that transformation of the hematopoietic cell lines Ba/F3, 32Dcl3, and MO7e with BCR/ABL results in an increase in reactive oxygen species (ROS) compared with quiescent, untransformed cells. The increase in ROS was directly due to BCR/ABL because it was blocked by the ABL-specific tyrosine kinase inhibitor STI571. Oxidative stress through ROS is believed to have many biochemical effects, including the potential ability to inhibit protein-tyrosine phosphatases (PTPases). To understand the significance of increased production of ROS, a model system was established in which hydrogen peroxide (H(2)O(2)) was added to untransformed cells to mimic the increase in ROS induced constitutively by BCR/ABL. H(2)O(2) substantially reduced total cellular PTPase activity to a degree approximately equivalent to that of pervanadate, a well known PTPase inhibitor. Further, stimulation of untransformed cells with H(2)O(2) or pervanadate increased tyrosine phosphorylation of each of the most prominent known substrates of BCR/ABL, including c-ABL, c-CBL, SHC, and SHP-2. Treatment of the BCR/ABL-expressing cell line MO7/p210 with the reducing agents pyrrolidine dithiocarbamate or N-acetylcysteine reduced the accumulation of ROS and also decreased tyrosine phosphorylation of cellular proteins. Further, treatment of MO7e cells with H(2)O(2) or pervanadate increased the tyrosine kinase activity of c-ABL. Drugs that alter ROS metabolism or reactivate PTPases may antagonize BCR/ABL transformation. 相似文献
20.
Majsterek I Sliwinski T Poplawski T Pytel D Kowalski M Slupianek A Skorski T Blasiak J 《Mutation research》2006,603(1):74-82
Imatinib mesylate (STI571), a specific inhibitor of BCR/ABL tyrosine kinase, exhibits potent antileukemic effects in the treatment of chronic myelogenous leukemia (CML). However, the precise mechanism by which inhibition of BCR/ABL activity results in pharmacological responses remains unknown. BCR/ABL-positive human K562 CML cells resistant to doxorubicin (K562DoxR) and their sensitive counterparts (K562DoxS) were used to determine the mechanism by which the STI571 inhibitor may overcome drug resistance. K562 wild type cells and CCRF-CEM lymphoblastic leukemia cells without BCR/ABL were used as controls. The STI571 specificity was examined by use of murine pro-B lymphoid Baf3 cells with or without BCR/ABL kinase expression. We examined kinetics of DNA repair after cell treatment with doxorubicin in the presence or absence of STI571 by the alkaline comet assay. The MTT assay was used to estimate resistance against doxorubicin and Western blot analysis with Crk-L antibody was performed to evaluate BCR/ABL kinase inhibition by STI571. We provide evidence that treatment of CML-derived BCR/ABL-expressing leukemia K562 cells with STI571 results in the inhibition of DNA repair and abrogation of the resistance of these cells to doxorubicin. We found that doxorubicin-resistant K562DoxR cells exhibited accelerated kinetics of DNA repair compared with doxorubicin-sensitive K562DoxS cells. Inhibition of BCR/ABL kinase in K562DoxR cells with 1 microM STI571 decreased the kinetics of DNA repair and abrogated drug resistance. The results suggest that STI571-mediated inhibition of BCR/ABL kinase activity can affect the effectiveness of the DNA-repair pathways, which in turn may enhance drug sensitivity of leukemia cells. 相似文献