Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.1.1.69 (BMT)
 2,655 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The use of bone marrow transplantation is increasing in the management of advanced cancers. In autologous bone marrow transplantation (ABMT), many investigators have attempted to purge the graft of residual tumor cells because of concern that reinfused tumor cells might contribute to relapse. The feasibility of various methods (exposure to chemical agents, monoclonal antibodies (MoAbs), toxins, dye, magnetic microparticles ... ) has been confirmed. In allogeneic bone marrow transplantation, clinical studies have related the prevention of graft-versus-host disease reaction through the partial depletion of T lymphocytes in the donor graft limited to 1 log to maintain a graft-versus-leukemia (GVL) effect. Similarly, the feasibility of different assays (soybean agglutinin, Moabs and magnetic microparticles) have been shown. However, the clinical benefit of BM purging remains to be demonstrated. For ABMT, only recent data on B-cell lymphoma and leukemia strongly support the clinical usefulness of an ex-vivo purging. For allogeneic BMT, one question remains controversial: is T lymphocytes depletion the best method for GVHD prevention?
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PMID:[Ex-vivo treatment of a bone marrow graft]. 160 93

The AML model in the BN rat has contributed considerably to improved understanding of the various aspects of leukaemia growth, responses to chemotherapy, application of BMT as treatment modality and the possibilities and limitations for the detection of residual disease during the remission phase. Obviously, there are restrictions with regard to the extrapolation of the rat data to the human situation. Leukaemia growth in inbred rats is highly reproducible, while in humans it presents a high degree of individual variation. However, several characteristics are shared and the aim should be to identify the similarities as well as the dissimilarities between human and rat leukaemia. In that way progress may be envisaged with respect to reaching the final goal of curing human leukaemia.
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PMID:Minimal residual disease in acute leukaemia: preclinical studies in a relevant rat model (BNML). 195 83

Mafosfamide (ASTA-Z) is a chemotherapeutic agent currently in use for in vitro purging of tumor-bearing human BM cells prior to autologous bone marrow transplantation (ABMT). We tested the efficacy of ASTA-Z against mouse plasmacytoma cells MOPC-315 (MOPC), a model of human multiple myeloma. BALB/c mice were injected intraperitoneally with different doses of MOPC preincubated with ASTA-Z. All control mice receiving > or = 10(4) MOPC intraperitoneally (ip) died within 23 days. All recipients of ASTA-Z pretreated MOPC remained healthy for > 180 days. To simulate the clinical situation, BALB/c mice received lethal doses of 10(3) MOPC ip prior to ABMT. Subsequently, mice were treated with cyclophosphamide 200 mg/kg one day prior to syngeneic BMT with 10(7) BMC containing 10(6) MOPC; 90% of the mice receiving unpurged syngeneic BMC died within 45 days whereas all mice transplanted with ASTA-Z-treated BMC/MOPC mixtures remained disease-free for > 100 days. Our results suggest that a similar approach may be successful in patients with multiple myeloma and residual disease prior to cryopreservation of their BM for ABMT. Bone marrow purging with ASTA-Z is effective and under certain conditions could be critical for prevention of relapse following ABMT, provided that effective elimination of residual disease in the host can be achieved by the conditioning regimen prior to ABMT.
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PMID:Successful purging of murine plasmacytoma by mafosfamide (ASTA-Z). 801 50

Detection of minimal residual disease is one of the major goals in bone marrow transplantation. We used a fluorescence in-situ hybridization technique to detect residual Philadelphia-chromosome positive cells in chronic myelogenous leukemia (CML) patients after sex-mismatch BMT. We analyzed the level of detection using probes for the BCR/ABL fusion product by comparison with results obtained with probes for the Y and X sex chromosomes. Detection of sex-mismatch chromosomes was significantly higher than that of the BCR/ABL translocation. In contrast, a higher specificity of residual tumor cell detection by the BCR/ABL probe was demonstrated because most of the sex-mismatch cells detected by FISH had a normal karyotype. Tumor-specific markers probes are thus superior and more accurate than sex-mismatch probes for detection of MRD in CML patients after BMT.
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PMID:Detection of minimal residual disease after sex-mismatch bone marrow transplantation in chronic myelogenous leukemia by fluorescence in situ hybridization. 817 87

Emergence of drug resistance with conventional cytotoxic therapy is a major challenge towards the curability of many cancers, especially in patients undergoing autologous BMT with ex-vivo purged hematopoietic support. We have explored the potential role of photoradiation therapy in purging hematopoietic stem cells of various hematological malignancies. Benzoporphyrin derivative, monoacid ring A (BPD-MA), dihematoporphyrin ether (DHE), and MC-540 were evaluated for the "ex-vivo" purging of residual tumor cells from autologous bone marrow (BM) grafts. BPD-MA and DHE photosensitizing activity was tested against two human large cell lymphoma cell lines and colony forming-unit leukemia (CFU-L) derived from patients with acute myelogenous leukemia (AML). In mixing experiments four log elimination of tumor cell lines was observed after 1 hr of incubation with BPD-MA or DHE followed by white light exposure. By comparison, using the same concentration of BPD-MA or DHE, the mean recovery of normal BM progenitors was 4-5.2% for granulocyte-macrophage colony forming unit (CFU-GM) and 5-9.8% for burst forming unit erythroid (BFU-E). The T lymphoblastic leukemia cell line CEM and its vinblastine (VBL)-resistant subline CEM/VBL100, along with the acute promyelocyte leukemia cell line HL-60 and its vincristine (VCR)-resistant subline HL-60/VCR, were also tested. Our results demonstrated the preferential cytotoxicity of BPD-MA and DHE toward neoplastic cell lines and CFU-L from AML patients. In addition, DHE was slightly more effective in purging tumor cells expressing the p-170 glycoprotein.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Newer options for treating drug-resistant (MDR+) cancer cells using photoradiation therapy. 818 Jun 6

Philadelphia positivity occurs in 20-25% of adult patients with ALL, the incidence increasing with age. 'Lymphoid-type' and 'stem cell-type' subgroups have been identified. Conventional chemotherapy is ineffective in eradicating the disease in the vast majority of patients. Allogeneic BMT is the only treatment currently available which offers a reasonable prospect of cure, with a 2 year actuarial survival of approximately 40% reported for patients transplanted in first remission or after relapse. In the absence of a histocompatible sibling, BMT from an unrelated donor early in first remission may be justified in young patients with 'lymphoid-type' disease which is characterised by a high rate of early relapse. The efficacy of ABMT in unproven; if used, purging should be considered as most harvested marrows have molecular evidence of residual disease. In the absence of BMT, experimental strategies such as therapy with cytokines to enhance differentiation of leukaemic blasts and maintenance interferon early after the attainment of CR should be considered.
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PMID:Approaches to the treatment of Philadelphia-positive acute lymphoblastic leukemia. 829 52

IL-2 has been used after autologous BMT (ABMT) with the aim of inducing graft versus leukemia (GVL) effect. Our studies in mice have shown that IL-2 therapy induces GVL effect when employed after BMT with bone marrow (BM) that has been activated with IL-2 in vitro (ABM). The present study was carried out to define the time of optimal GVL effect after BMT so that the immunomodulatory approaches could be concentrated at the time of maximum GVL effect. Our data show that GVL effect was induced if IL-2 was instituted immediately after BMT with ABM in mice with acute myeloid leukemia; institution of IL-2 1 week after BMT with ABM did not induce GVL effect. IL-2 therapy instituted immediately or 1 week after BMT with fresh bone marrow (FBM) did not induce any GVL effect. A significant increase in the NK activity was noticed whether IL-2 was instituted immediately or 1 week after BMT, either with FBM or with ABM. To evaluate the ability of IL-2 in the eradication of residual disease from the autograft and the host, BM with variable infiltration with leukemia was activated with IL-2 and used for BMT in leukemic mice. The GVL effect of BM with minimal leukemic infiltration (absence of morphologically demonstrable disease) was comparable to the GVL effect of normal BM. These findings suggest that: (a) maximum GVL effect after BMT with ABM is concentrated in the early post-transplant period possibly because of minimal residual disease during this time; (b) an increase in the NK activity induced by IL-2 therapy may not predict for an improved GVL effect; and (c) for optimum GVL effect, BM with minimal leukemic infiltration should be activated with IL-2 before BMT.
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PMID:Graft versus leukemia effect after transplantation with interleukin-2-activated bone marrow. Correlation with eradication of residual disease. 833 64

The very rapid development in the last few years of techniques based on use of the polymerase chain reaction (PCR) for characterizing molecular lesions in leukaemia and lymphoma now offers the opportunity for monitoring residual disease at a sensitivity of one malignant cell in 10(5) or 10(6) normal cells. Maximal specificity is presumably achieved when the DNA sequences amplified are truly leukaemia-specific, such as BCR/ABL in chronic myelogenous leukemia, RARA PML/RARA in t(15;17) acute myelogenous leukemia, DEK/CAN in t(6;9) AML, PBX1/E2A in t(1;19) acute lymphoblastic leukemia (ALL), or TAL-1 deletions in other T-ALLs. Comparable sensitivity may be achieved by using immunoglobulin heavy chain (IGH) and T-cell receptor (TCR) gene rearrangements if a clonospecific probe can be generated. However, the presence of similar sequences in IgH genes from normal B lymphocytes may decrease the specificity. For clinical purposes the crucial issues are the following. Can PCR techniques be used for confirmation of diagnosis and evaluation of extent of disease? Can PCR data obtained in remission provide information about the probability of cure or of relapse? Can techniques be developed to quantitate the PCR product and thereby increase its predictive value? These and other issues were addressed at the 4th Workshop of the Molecular Biology/BMT Study Group that took place in Bristol UK on 9-10 May 1992.
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PMID:Molecular evidence of minimal residual disease after treatment for leukaemia and lymphoma: an updated meeting report and review. 835 Jun 33

When allogeneic BMT is used for the treatment of leukemia, depletion of T cells from the donor BM to avoid GVHD may be accompanied by persistence of host cells and post-transplant relapse. In this report, a murine model of MHC-compatible BMT was used to show that delayed infusion of immunocompetent donor cells early after T cell-deficient BMT eliminated residual host cells and provided an antileukemic effect without causing lethal GVHD. AKR (H-2k) recipient mice were pre-conditioned with 9 Gy total body irradiation (LD50) and transplanted with 10(7) BM cells from MHC-matched B10.BR donors. These mice did not develop GVHD and became stable, long-term mixed (donor-host) T cell chimeras. In this model, mixed or incomplete donor T cell chimerism was associated with decreased GVL reactivity. AKR hosts that were transplanted with B10.BR bone marrow admixed with 3 x 10(7) B10.BR spleen cells (as a source of T cells) became complete donor T cell chimeras, but they developed severe and lethal GVHD. However, when the infusion of donor spleen cells was delayed until 21 days after BMT, few mice exhibited any clinical signs of GVHD, and > 95% of the mice became long-term survivors. The infused spleen cells eliminated residual host T cells by 21 days after infusion, and most chimeras were able to resist a supralethal challenge with AKR leukemia/lymphoma cells. Thus, post-transplant adoptive immunotherapy with normal mononuclear cells from the marrow donor may be an effective way to eliminate residual disease or treat leukemia relapse after BMT without causing significant GVHD.
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PMID:Delayed infusion of normal donor cells after MHC-matched bone marrow transplantation provides an antileukemia reaction without graft-versus-host disease. 848 80

The polymerase chain reaction (PCR) was used to amplify the bcr/abl transcript as a marker of minimal residual disease (MRD) in 76 patients with chronic myeloid leukemia (CML) subjected to allogeneic BMT and in complete hematological remission. We examined 56 patients transplanted in chronic phase (CP) and 20 in advanced phase (AD), including 16 in accelerated phase and four in blastic transformation. A total of 135 samples collected between 4 and 105 months from BMT were analyzed and the PCR analysis was positive in 33 (24%) samples from 20 patients. The bcr/abl chimeric transcript was detected in 7/13 (54%) patients analyzed within 1 year and in 21/88 (23%) beyond 1 year from BMT. Fluctuation of the residual disease at the molecular level in individual patients was recorded. The results have been correlated with a number of clinical parameters obtained before and after BMT; among the tested variables only the phase of the disease at BMT was associated with higher frequency of PCR positivity after BMT. The probability of finding persisting disease 1 year beyond BMT was significantly higher (P = 0.00005) in patients allografted in AD (14/26, 54%) as compared to patients grafted in CP (7/62, 11%). At any interval from BMT the difference between the two groups remained statistically significant: the bcr/abl transcript was present in 5/31 patients transplanted in CP compared to 9/15 patients transplanted in AD (P = 0.003) between 12 and 36 months from BMT, and in 2/31 CP vs 5/11 AD patients (P = 0.008) beyond 36 months from BMT.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:bcr/abl chimeric transcript in patients in remission after marrow transplantation for chronic myeloid leukemia: higher frequency of detection and slower clearance in patients grafted in advanced disease as compared to patients grafted in chronic phase. 852 78


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