Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.7.10.2 (focal adhesion kinase)
44,029 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

To determine the source of residual disease detected in patients with chronic myeloid leukaemia (CML) in complete cytogenetic remission (n=8) after treatment with interferon-alpha (IFN-alpha), we have tested CFU-GM colonies grown from bone marrow mononuclear cells or from plastic-adherent (Pdelta) cells for BCR-ABL mRNA using a nested multiplex RT-PCR. We compared our results with those obtained by analysis of colonies from newly diagnosed patients (n=4) and patients achieving no cytogenetic response (n=1) or incomplete cytogenetic response to treatment with IFN-alpha (n=5). A total of 1239 informative colonies were analysed. A small proportion of BCR-ABL-positive colonies was detected in all eight patients in complete cytogenetic remission, suggesting the persistence of leukaemia that could potentially lead to relapse. The overall proportion of BCR-ABL-positive colonies in patients achieving a cytogenetic response to IFN-alpha correlated with the levels of BCR-ABL transcripts detected in the peripheral blood by competitive RT-PCR (P=0.004). We conclude that residual disease detected in the peripheral blood of complete cytogenetic responders to IFN-alpha is at least partly derived from clonogenic myeloid cells. It is probable that the leukaemia clone in CML is only very rarely or never entirely eradicated by treatment with IFN-alpha.
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PMID:BCR-ABL-positive progenitors in chronic myeloid leukaemia patients in complete cytogenetic remission after treatment with interferon-alpha. 975 56

We report a patient with Ph chromosome-positive CML who underwent an HLA-identical T cell-depleted BMT from a sibling donor. DNA polymorphism analysis showed complete donor chimaerism after BMT, followed by mixed chimaerism of granulocytes, natural killer cells and B lymphocytes, with T lymphocytes host-derived at day +120 post BMT. From month +20 haematopoiesis was exclusively of host origin in all cell lineages. RT-PCR was used in order to detect residual disease, but at the time, analysis did not show BCR-ABL transcripts. This case is unusual in that non-malignant stem cells of recipient origin survived the transplant and reconstituted haematopoiesis after BMT. Two years post transplant, no molecular or haematological relapse was documented. The observation that subsequent recipient recovery without molecular relapse implies that, at least in this case, the GVL effect can occur in the absence of donor T cells.
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PMID:Autologous reconstitution with BCR-ABL-negative haematopoiesis after T cell-depleted allogeneic BMT for CML. 975 52

Approximately 2-5% of children with newly diagnosed acute lymphoblastic leukemia (ALL) have a Philadelphia (Ph) chromosome detectable on cytogenetic analysis, which is associated with a poor prognosis. In rare ALL cases the Ph chromosome may appear in leukemic cells during the course of the disease. We report here the case of a 5.5-year-old male patient with T-ALL who was found to have the b2a2 BCR-ABL mRNA transcript by reverse transcriptase-polymerase chain reaction (RT-PCR) at first marrow relapse. At the time of initial diagnosis, no BCR-ABL transcripts had been detected by PCR in the patient's blood and marrow samples. Further studies were performed using a competitive PCR titration assay and the fluorescence in situ hybridization (FISH) method to monitor the leukemic clone. Progression of the disease was associated with a higher BCR-ABL transcript level and an increasing proportion of BCR-ABL-positive cells. Metaphase FISH analysis identified the presence of the BCR-ABL fusion gene on a normal chromosome 22. This study shows that a late-appearing Ph translocation in ALL may be cytogenetically invisible. Quantitative RT-PCR and FISH techniques are appropriate and efficient methods for detecting these rare ALL variants expressing the BCR-ABL fusion gene and for estimating the level of residual disease following treatment.
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PMID:Molecular detection of a late-appearing BCR-ABL gene in a child with T-cell acute lymphoblastic leukemia. 976 Jan 54

The principle aim of residual disease analysis in patients with chronic myeloid leukaemia (CML) is to gauge patient response to treatment and, in patients after allogeneic BMT, to enable early diagnosis of relapse. RT-PCR is by far the most sensitive assay to detect residual disease in CML and can enable a single leukaemia cell to be detected in a background of 10(5)-10(6) normal cells. This is approximately 1000 x greater than the routine detection limit of the other methods. After allogeneic BMT, many CML patients are BCR-ABL positive for prolonged periods of time without subsequently relapsing. Thus the simple presence or absence of residual BCR-ABL transcripts in patients' leukocytes is of little value in the management of individual cases. Quantitative PCR techniques can distinguish between those PCR positive patients who have low or falling BCR-ABL levels on sequential analysis from those who have levels that are increasing. Provided assays are performed frequently enough, rising or persistently high numbers of BCR-ABL transcripts can be detected prior to frank relapse and this information may be used for early therapeutic intervention. Most patients who respond to treatment for relapse by donor lymphocyte infusion (DLI) achieve durable molecular remission. Quantitative PCR is also useful to gauge the response of CML patients to IFN-alpha. We have found that the great majority of patients in complete cytogenetic remission after treatment with IFN-alpha remain PCR positive and harbour a minority population of BCR-ABL positive myeloid precursor cells. It is unlikely therefore this treatment modality completely eliminates the disease in any patient.
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PMID:Minimal residual disease in chronic myeloid leukaemia. 984 16

Chronic myelogenous leukemia (CML) is characterized by a balanced translocation that leads to the formation of the the BCR-ABL fusion gene. Although autografts can prolong the life of CML patients, patients relapse owing to malignant cells that persist in the graft and the host. This review discusses various experimental strategies that target the BCR-ABL gene or gene products that are downstream of it. Various strategies have been adopted to block BCR-ABL at the gene, mRNA and protein level. One promising strategy involves the cotransduction of a patient's hematopoietic stem cells (HSCs) with anti-BCR-ABL antisense sequences and a drug resistance gene. This might allow for the elimination of any residual disease in the graft or host by chemotherapy while rendering any drug-resistant, malignant CML HSCs functionally normal.
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PMID:Gene therapy for chronic myelogenous leukemia. 1043 Nov 69

We sought to establish a rapid and reliable RT-PCR approach for detection and quantification of BCR-ABL fusion transcripts using the LightCycler technology. This device combines rapid thermocycling with online detection of PCR product formation and is based on the fluorescence resonance energy transfer (FRET) between two adjacent hybridization probes carrying donor and acceptor fluorophores. A pair of probes was designed that was complementary to ABL exon 3, thus enabling detection of all known BCR-ABL variants and also normal ABL as an internal control. Conditions were established to amplify less than 10 target molecules/reaction and to detect one CML cell in 105 cells from healthy donors. To determine the utility of the assay, we quantified BCR-ABL and ABL transcripts in 254 samples (222 peripheral blood, 32 bone marrow) from 120 patients with CML after therapy with IFN-alpha (n = 219), allogeneic BMT (n = 17), chemotherapy (n = 11), or at diagnosis (n = 7). The level of residual disease in the 245 BCR-ABL positive specimens was expressed as the ratio of BCR-ABL/ABL. This ratio was compared to results obtained by three established methods from contemporaneous specimens. A highly significant correlation was seen between the BCR-ABL/ABL ratios determined by the LightCycler and (1) the BCR-ABL/ABL ratios obtained by nested competitive RT-PCR (n = 201, r = 0.90, P < 0. 0001); (2) the proportion of Philadelphia chromosome positive metaphases determined by cytogenetics (n = 81, P < 0.0001); and (3) the BCR ratio determined by Southern blot analysis (n = 122, P < 0. 0001). We conclude that real-time PCR with hybridization probes is a reliable and sensitive method to monitor CML patients after therapy. The major advantages of the methodology are (1) amplification and product analysis are performed in the same reaction vessel, avoiding the risk of contamination; (2) the results are standardized by the quantification of housekeeping genes; and (3) the complete PCR analysis takes less than 60 min.
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PMID:Accurate and rapid analysis of residual disease in patients with CML using specific fluorescent hybridization probes for real time quantitative RT-PCR. 1055 58

A substantial minority of patients with chronic myelogenous leukemia (CML) achieve a complete response (CR) to treatment with interferon-alpha (IFN), defined as the disappearance of Philadelphia chromosome-positive metaphases. Currently it is unclear how long IFN treatment should be continued for such patients. We used a competitive reverse transcriptase-polymerase chain reaction (RT-PCR) to quantify levels of BCR-ABL transcripts in 297 peripheral blood specimens collected from 54 patients who had achieved CR with IFN. The median duration of observation was 1.9 years (range, 0.3-11.0 years). Total ABL transcripts were quantified as internal control and results were expressed as the ratio BCR-ABL/ABL. All 54 patients had molecular evidence of residual disease, although 3 patients were intermittently PCR negative. The median BCR-ABL/ABL ratio at the time of maximal response for each patient was 0.045% (range, 0%-3. 6%). During the period of observation 14 patients relapsed, 11 cytogenetically to chronic phase disease and 3 directly to blastic phase. The median ratio of BCR-ABL/ABL at maximal response was significantly higher in patients who relapsed than in those who remained in CR (0.49% versus 0.021%, P < 0.0001). Our findings show that the level of residual disease falls with time in complete responders to IFN, but molecular evidence of disease is rarely if ever eliminated. The actual level of minimal residual disease correlates with the probability of relapse. We suggest that for patients who reach CR, IFN should be continued at least until relatively low levels of residual leukemia are achieved. (Blood. 2000;95:62-66)
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PMID:Molecular heterogeneity in complete cytogenetic responders after interferon-alpha therapy for chronic myelogenous leukemia: low levels of minimal residual disease are associated with continuing remission. German CML Study Group and the UK MRC CML Study Group. 1060 85

In recent years, the prognosis of chronic myeloid leukemia (CML) has been greatly improved either with interferon-alpha (IFN-alpha) therapy or allogeneic bone marrow transplantation (BMT). In the present study, minimal residual disease was evaluated in 21 patients in complete cytogenetic response (CCR) after such treatments. Samples from bone marrow aspirates or peripheral blood or both were analyzed by conventional cytogenetics, Southern blot, interphase fluorescent in situ hybridization (FISH), and quantitative reverse transcription-polymerase chain reaction (Q-RT-PCR). In all patients, FISH detected 1% to 12% nuclei with a BCR-ABL fusion gene, whereas Q-RT-PCR experiments were negative or weakly positive. Based on these results, we hypothesize that the BCR-ABL genomic rearrangement persists unexpressed in nonproliferating cells whatever the treatment (IFN-alpha or BMT). These data point to the need for follow-up of CML patients in CCR over an extensive period at the DNA level (FISH) to evaluate the residual disease and at the RNA level (Q-RT-PCR) to estimate the risk of relapse. (Blood. 2000;95:404-408)
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PMID:Persistence of BCR-ABL genomic rearrangement in chronic myeloid leukemia patients in complete and sustained cytogenetic remission after interferon-alpha therapy or allogeneic bone marrow transplantation. 1062 42

The degree of tumor load reduction after therapy is an important prognostic factor for patients with CML. Conventional metaphase analysis has been considered to be the 'gold standard' for evaluating patient response to treatment but this technique normally requires bone marrow aspiration and is therefore invasive. The frequency of cytogenetic analyses can be considerably reduced if patients are also monitored by molecular methods, which can be performed on peripheral blood specimens. Of the various techniques available, most attention has been paid to RT-PCR for BCR-ABL mRNA since this is by far the most sensitive. Simple, non-quantitative RT-PCR analysis gives only limited information on patients after treatment. Quantitative RT-PCR assays have been developed to monitor the kinetics of residual BCR-ABL transcripts over time. Variables in the quantitative PCR assay may be controlled for by quantification of transcripts of a normal gene (eg ABL or glucose-6-phosphate dehydrogenase, G6PD) as an internal standard. After allogeneic stem cell transplantation, most patients become RT-PCR negative, often after a period of low level positivity that may persist for several months. Those patients destined to relapse are characterized by the reappearance and/or rising levels of BCR-ABL transcripts. In contrast, for patients treated with interferon-alpha (IFN) residual disease is rarely, if ever, eliminated. The actual level of minimal residual disease in complete cytogenetic responders to IFN correlates with the probability of relapse. New quantitative real time procedures promise to simplify the protocols that are currently in use, but standardization and the introduction of rigorous, internationally accepted controls are required to enable RT-PCR to become a robust and routine basis for therapeutic decisions.
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PMID:Detection and quantification of residual disease in chronic myelogenous leukemia. 1086 64

The management of chronic myelogenous leukemia (CML) has become complex due to the availability of improved diagnostic procedures and life-prolonging or even curative treatment strategies that are more successful the earlier they are applied in the course of the disease. This is true for allogeneic bone-marrow transplantation, treatment with interferon alpha (IFN) and Philadelphia-negative stem-cell collections for autografting. Outcome differs according to risk profiles of patients at diagnosis. In addition, molecular techniques for the detection of the BCR-ABL fusion gene or its products, such as the reverse-transcriptase polymerase chain reaction (PCR), Southern blot analysis, or fluorescence in situ hybridization, facilitate accurate diagnosis and the monitoring of residual disease. They allow the individualization of treatment such as early infusion of donor lymphocytes if molecular relapse is detected after allografting, or discontinuation of IFN in the presence of very low BCR-ABL transcript levels). The availability of real-time PCR devices further improves and accelerates the diagnosis and monitoring of residual disease. This article addresses recent developments in drug therapy and allografting, including treatment intensification with low-dose ara C or intensive chemotherapy followed by autografting, introduction of new drugs (such as homoharringtonine or tyrosine kinase inhibitor STI571), progress with unrelated donor transplantations, use of peripheral blood stem cells for allografting, and transplantation without myeloablative conditioning. Tradeoffs between the treatment options will be discussed in the context of the evidence-based guidelines for treating CML, as recently published by the American Society of Hematology. Finally, the new competence network on acute and chronic leukemias will be introduced.
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PMID:Current trends in the management of chronic myelogenous leukemia. 1096 82


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