Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0023473 (chronic myeloid leukemia)
 18,916 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Imatinib mesylate (STI571) is a competitive Bcr-Abl tyrosine kinase inhibitor and has yielded encouraging results in treatment of chronic myelogenous leukemia (CML) and gastrointestinal stroma tumors (GISTs). Apart from inhibition of the Abl protein tyrosine kinases, it also shows activity against platelet-derived growth factor receptor (PDGF-R), c-Kit, Abl-related gene (ARG), and their fusion proteins while sparing other kinases. In vitro studies have revealed that imatinib mesylate can inhibit growth of cell lines and primitive malignant progenitor cells in CML expressing Bcr-Abl. However, little is known about the effects of imatinib mesylate on nonmalignant hematopoietic cells. In the current study we demonstrate that in vitro exposure of mobilized human CD34+ progenitors to therapeutic concentrations of imatinib mesylate (1-5 microM) inhibits their differentiation into dendritic cells (DCs). DCs obtained after 10 to 16 days of culture in the presence of imatinib mesylate showed concentration-dependent reduced expression levels of CD1a and costimulatory molecules such as CD80 and CD40. Furthermore, exposure to imatinib mesylate inhibited the induction of primary cytotoxic T-lymphocyte (CTL) responses. The inhibitory effects of imatinib mesylate were accompanied by down-regulation of nuclear localized RelB protein. Our results demonstrate that imatinib mesylate can act on normal hematopoietic cells and inhibits the differentiation and function of DCs, which is in part mediated via the nuclear factor kappaB signal transduction pathway.
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PMID:Imatinib mesylate affects the development and function of dendritic cells generated from CD34+ peripheral blood progenitor cells. 1497 62

Vaccination with autologous leukaemia-derived dendritic cells (DC) presents an adjuvant treatment option for chronic myeloid leukaemia (CML). Here, we show that high-efficiency CD40-targeted adenoviral gene transfer of GM-CSF to CML-derived DC induces long-lived maturation in the absence of exogenous cytokines and may thus ensure protracted stimulation of CML-specific T cells upon vaccination.
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PMID:CD40-targeted adenoviral GM-CSF gene transfer enhances and prolongs the maturation of human CML-derived dendritic cells upon cytokine deprivation. 1452 Apr 39

The primary granule proteins (PGP) of myeloid cells are a source of multiple antigens with immunotherapeutic potential for myeloid leukemias. Therefore, we developed a method to induce T-cell responses to PGP protein sequences. We found that gene-transfected antigen-presenting cells efficiently expand functionally competent PGP-specific CD4 and CD8 T cells. The system was optimized using T-cell responses to autologous CD40-activated B cells (CD40-B) transfected with a cytomegalovirus pp65-encoding expression vector. To generate leukemia-specific T cells, expression vectors encoding the PGP proteinase 3 (PR3), human neutrophil elastase, and cathepsin-G were transfected into CD40-B cells to stimulate post-allogeneic stem cell transplantation T cells from five patients with myeloid and three with lymphoid leukemias. T-cell responses to PGP proteinase 3 and human neutrophil elastase were observed in CD8+ and CD4+ T cells only in patients with myeloid leukemias. T-cell responses against cathepsin-G occurred in both myeloid and lymphoblastic leukemias. T cells from a patient with chronic myelogenous leukemia (CML) and from a posttransplant CML patient, expanded against PGP, produced IFN-gamma or were cytotoxic to the patient's CML cells, demonstrating specific antileukemic efficacy. This study emphasizes the clinical potential of PGP for expansion and adoptive transfer of polyclonal leukemia antigen-specific T cells to treat leukemia.
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PMID:In vitro induction of myeloid leukemia-specific CD4 and CD8 T cells by CD40 ligand-activated B cells gene modified to express primary granule proteins. 1595 35

To study the influence of IFN-alpha on function of CML-DC cultured in vitro and expression of chemokine and its chemokine receptor, bone marrow mononuclear cells from 13 CML patients were cultured in the fetal calf serum culture system supplemented with rhSCF, rhFlt-3L for expansion system, and adding rhGM-CSF, rhTNF-alpha, rhIL-4, with or without rhIFN-alpha to induce DCs. After incubation for two weeks, the phenotypes of CML-DC were analyzed by direct immunofluorescence and flow cytometry. The concentration of MIP-3beta expressed by CML-DC in the supernatant were analyzed by ELISA. The proliferative ability of T cells from healthy volunteers stimulated by CML-DCs were measured by MTT assay. The results showed that expression of CD86, CD83, CD40, MHC-I class molecules, CCR7, the concentration of MIP-3beta expressed by CML-DC, and the proliferative ability of T cells stimulated by CML-DCs in IFN-alpha group were all significantly higher than that in control group (P < 0.01). It is concluded that the immunophenotype of CML-DCs can be partially changed by IFN-alpha to accelerate the maturation of CML-DCs, enhance the capacity of CML-DCs, and stimulate allogeneic T lymphocyte proliferation.
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PMID:[Influence of IFN-alpha on function of CML-DC in vitro and expression of chemokine with its receptor]. 1597 48

Leukemic bcr-abl positive dendritic cells (DCs) are likely to be present in vivo in chronic myelogenous leukemia (CML) patients, but no data are available on their functional qualities. We analyzed the circulating BDCA-1+ myeloid DC compartment in 15 chronic phase CML patients. Phenotypic features of CML DCs were comparable with that of normal DCs, except for the CD80 and CD40 antigens, significantly under-represented in CML patients. Nonetheless, no differences were found between normal samples and leukemic DCs in the allostimulatory ability, as well as in the production of cytokines and polarization of T cell responses. CML DCs were analyzed by fluorescence in situ hybridization (FISH) and found positive for the bcr-abl translocation. However, when bcr-abl+ DCs were tested for their ability to stimulate an autologous T-cell response in vitro, we could not detect a specific recognition. We conclude that an apparently normal circulating DC compartment carrying the Ph+ chromosome can be identified in CML patients; however, these cells appear unable to trigger a protective anti-leukemic immune response in autologous T cells.
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PMID:Circulating myeloid dendritic cell directly isolated from patients with chronic myelogenous leukemia are functional and carry the bcr-abl translocation. 1652 50

Specific immunotherapies for patients with chronic myeloid leukemia (CML) might eliminate residual CML cells after therapy with imatinib or chemotherapy and might enhance a specific graft-versus-leukemia effect after allogeneic stem cell transplantation. Here, we investigated the mRNA expression and T-cell recognition of tumor-associated antigens or leukemia-associated antigens (LAAs) in 34 patients with CML. Several LAAs are expressed in CML and therefore are candidate structures for specific immunotherapies: bcr-abl (100%), G250 (24%), hTERT (53%), MPP11 (91%), NEWREN60 (94%), PRAME (62%), Proteinase3 (71%), RHAMM/CD168 (83%), and WT1 (53%), but not BAGE, MAGE-A1, SSX2, or NY-ESO-1. The frequency of mRNA expression of RHAMM/CD168, Proteinase3, and PRAME was higher in acceleration phase and blast crisis. In flow cytometry, CD34+ progenitor cells typed positive for HLA molecules but were deficient for CD40, CD80, CD83, and CD86. However, RHAMM/CD168 R3-peptide (ILSLELMKL)-specific T-cell responses in CML patients were demonstrated by ELISPOT analysis and specific lysis of RHAMM/CD168 R3-pulsed T2 cells and CD34+ CML cells in chromium-51 release assays. RHAMM-R3-specific T cells could be phenotyped as CD8+R3*tetramer+CD45RA+CCR7-CD27- early effector T cells by tetramer staining. Therefore, vaccination strategies inducing such RHAMM-R3-directed effector T cells might be a promising approach to enhance specific immune responses against CML cells.
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PMID:Chronic myeloid leukemia cells express tumor-associated antigens eliciting specific CD8+ T-cell responses and are lacking costimulatory molecules. 1715 68

This study was aimed to investigate the influences of interferonalpha (IFN-alpha) on expressions of CCR7, interleukin10 (IL-10) and IL-12p70 in dendritic cells (DCs) from patients with chronic myeloid leukemia (CML). In addition to stem cell factor (SCF), granulocyte-macrophage colony stimulating factor (GM-CSF), tumor necrosis factor-alpha (TNF-alpha) and IL-4, IFN-alpha was added to the serum-free medium of DCs. After culture for 10-14 days, phenotypes and function of CML-DCs were evaluated respectively by flow cytometry and methyl thiazolyl tetrazolium (MTT) assay. Chromosome of DCs was analyzed by displaying G banding assay. The concentrations of IL-10 and IL-12P70 in supernatants were evaluated by enzyme-linked immunosorbent assay (ELISA). The results showed that the expressions of CD40, CD83, CD86 and CCR7 and the OD value in allogeneic mixed-lymphocyte reaction (MLR) in group with IFN-alpha (300 U/ml) were twice as high as those in group without IFN-alpha. The percentage of Ph1 positive cells and concentrations of IL-10 and IL-12 P70 were reduced in group with IFN-alpha. It is concluded that the defective phenotypes and functions of CML-DCs can be recruited partly by IFN-alpha. The mechanism may lie in the facts that expression of CCR7 and co-stimulatory molecules is promoted and the inhibitory effect of IL-10 on CML-DCs is relieved partly through the regulation of IFN-alpha.
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PMID:Influences of interferon-alpha on expression of Th cytokines and CCR7 in dendritic cells from patients with chronic myeloid leukemia in vitro. 1842 74

The purpose of this study is to investigate whether hematopoiesis capacity, immunomodulatory effect and ex vivo expansion potential of mesenchymal stem cells (MSCs) are affected by cryopreservation. Chronic myeloid leukemia (CML) patients' bone marrow MSCs cryopreserved for 3 months, 6 months, and 1 year were thawed and analyzed. Cryopreserved CML-MSCs have more than 90% viability. Cell-doubling time of cryopreserved CML-MSCs is 42 to 54 hours. Cells have been expanded in culture for more than 30 passages. Under suitable conditions, cryopreserved CML-MSCs have the ability of multiple lineages differentiation, including bone, endothelial, fat and nerve. Furthermore, cryopreserved CML-MSCs express hematopoietic cytokines, and possess hematopoietic supportive ability. The growth of normal long-term culture-initiating cell (LTC-IC) on CML-MSCs (including noncryopreserved and cryopreserved CML-MSCs) was similar to that of normal derived MSCs. Cryopreserved CML-MSCs did not express costimulatory molecules CD40, CD80, and CD86. They can inhibit T lymphocyte proliferation induced by mitogens. The immunosuppressive effect of cryopreserved CML-MSCs on T-cell proliferation was dose dependent. These findings indicate that cryopreserved CML derived MSCs may be a useful tool for clinical application.
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PMID:Hematopoiesis capacity, immunomodulatory effect and ex vivo expansion potential of mesenchymal stem cells are not impaired by cryopreservation. 1844 60

In lymph node (LN) proliferation centers in chronic lymphocytic leukemia (CLL), the environment protects from apoptotic and cytotoxic triggers. Here, we aimed to define the molecular basis for the increased drug resistance and searched for novel strategies to circumvent it. The situation in CLL LN could be mimicked by prolonged in vitro CD40 stimulation, which resulted in up-regulation of antiapoptotic Bcl-xL, A1/Bfl-1, and Mcl-1 proteins, and afforded resistance to various classes of drugs (fludarabine, bortezomib, roscovitine). CD40 stimulation also caused ERK-dependent reduction of Bim-EL protein, but ERK inhibition did not prevent drug resistance. Drugs combined with sublethal doses of the BH3-mimetic ABT-737 displayed partial and variable effects per individual CD40-stimulated CLL. The antiapoptotic profile of CD40-triggered CLL resembled BCR-Abl-dependent changes seen in chronic myeloid leukemia (CML), which prompted application of c-Abl inhibitors imatinib or dasatinib. Both compounds, but especially dasatinib, prevented the entire antiapoptotic CD40 program in CLL cells, and restored drug sensitivity. These effects also occurred in CLL samples with dysfunctional p53. Importantly, ex vivo CLL LN samples also displayed strong ERK activation together with high Bcl-xL and Mcl-1 but low Bim levels. These data indicate that CLL cells in chemoresistant niches may be sensitive to therapeutic strategies that include c-Abl inhibitors.
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PMID:c-Abl kinase inhibitors overcome CD40-mediated drug resistance in CLL: implications for therapeutic targeting of chemoresistant niches. 1906 35

Mesenchymal stem cells (MSCs) have emerged as excellent candidates for clinical application because of their capabilities of differentiating into multiple mesenchymal lineages and supporting hematopoiesis. Recently, MSCs have gained further interests after the demonstration of an immunosuppressive role. However, it is still unclear whether the immunosuppressive capability of MSCs will be altered with disease state. In this study, we obtained and expanded MSCs from bone marrow of patients with chronic myeloid leukemia (CML). Our results showed that MSCs derived from CML do not express costimulatory molecules CD40, CD80, and CD86. When MSCs derived from CML were added back to T cells stimulated by mitogens, a significant inhibition of T-cell proliferation was evident. MSCs differentiated into various mesenchymal lineages did not alter their immunosuppressive effect on T-cell proliferation. A significant T-cell inhibition was found in a transwell system, in which cell-cell contact between MSCs and effector cells was prevented. Furthermore, we found that transforming growth factor beta1 (TGF beta1) and hepatocyte growth factor (HGF) were major mediators of T-cell suppression by MSCs derived from CML. These results demonstrated that autologous MSCs derived from CML could effectively suppress T-cell proliferation.
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PMID:Immunosuppressive properties of mesenchymal stem cells derived from bone marrow of patients with chronic myeloid leukemia. 1882 Dec 19


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