Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

---

Query: EC:2.7.10.2 (focal adhesion kinase)
44,029 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Imatinib has revolutionized drug therapy of chronic myeloid leukemia (CML). Preclinical studies were promising but the results of clinical trials by far exceeded expectations. Responses in chronic phase are unprecedented, with rates of complete cytogenetic response (CCR) of more than 40% in patients after failure of interferon-alpha (IFN) and more than 80% in newly diagnosed patients, a level of efficacy that led to regulatory approval in record time. While most of these responses are stable, resistance to treatment after an initial response is common in more advanced phases of the disease. Mutations in the kinase domain (KD) of BCR-ABL that impair imatinib binding have been identified as the leading cause of resistance. Patients with CCR who achieve a profound reduction of BCR-ABL mRNA have a very low risk of disease progression. However, residual disease usually remains detectable with reverse transcription-polymerase chain reaction (RT-PCR), indicating that disease eradication may pose a significant challenge. The mechanisms underlying the persistence of minimal residual disease are unknown. In this manuscript, we review the preclinical and clinical development of imatinib for the therapy of CML, resistance and strategies that may help to eliminate resistant or residual leukemia.
...
PMID:The development of imatinib as a therapeutic agent for chronic myeloid leukemia. 1561 70

We monitored BCR-ABL transcript levels by quantitative real-time PCR in 103 patients treated with imatinib for chronic myeloid leukaemia in chronic phase for a median of 30.3 months (range 5.5-49.9) after they achieved complete cytogenetic remission (CCyR). The patients could be divided into three groups: (1) in 32 patients transcript levels continued to decline during the period of observation (nadir BCR-ABL/ABL ratio 0.015%); in five of these patients BCR-ABL transcripts became undetectable on repeated testing, (2) in 42 patients the transcript levels reached a plateau and (3) in 26 patients transcript numbers increased and the initial CCyR was lost. Three patients were not evaluable. Patients who remained in CCyR for at least 24 months appeared to have a low risk of subsequent cytogenetic relapse. We conclude that the pattern of 'residual' disease after achieving CCyR on imatinib is variable: some patients in CCyR show a progressive reduction in the level of residual disease, some reach a plateau where transcript numbers are relatively stable and others relapse with Ph-positive metaphases.
...
PMID:Monitoring patients in complete cytogenetic remission after treatment of CML in chronic phase with imatinib: patterns of residual leukaemia and prognostic factors for cytogenetic relapse. 1570 81

Philadelphia chromosome-positive (Ph+) acute lymphoblastic leukemia (ALL) has a dismal prognosis. We prospectively evaluated minimal residual disease (MRD) by measuring BCR/ ABL levels with a quantitative real-time PCR procedure after induction and after consolidation in 45 adults with Ph+ ALL who obtained complete hematological remission after a high-dose daunorubicin induction schedule. At diagnosis, the mean BCR-ABL/GUS ratio was 1.55 +/- 1.78. A total of 42 patients evaluable for outcome analysis were operationally divided into two MRD groups: good molecular responders (GMRs; n = 28) with > 2 log reduction of residual disease after induction and > 3 log reduction after consolidation therapy, and poor molecular responders (PMRs; n = 14) who, despite complete hematological remission, had a higher MRD at both time points. In GMR, the actuarial probability of relapse-free, disease-free and overall survival at two years was 38, 27 and 48%, respectively, as compared to 0, 0 and 0% in PMR (P = 0.0035, 0.0076 and 0.0026, respectively). Salvage therapy induced a second sustained complete hematological remission in three GMR patients, but in no PMR patient. Our data indicate that, as already shown in children, adult Ph+ ALL patients have a heterogeneous sensitivity to treatment, and that early quantification of residual disease is a prognostic parameter in this disease.
...
PMID:Significant reduction of the hybrid BCR/ABL transcripts after induction and consolidation therapy is a powerful predictor of treatment response in adult Philadelphia-positive acute lymphoblastic leukemia. 1574 51

Imatinib-refractory chronic myelogenous leukemia (CML) patients can experience long-term disease-free survival with myeloablative therapy and allogeneic hematopoietic cell transplantation; however, associated complications carry a significant risk of mortality. Transplantation of autologous hematopoietic cells has a reduced risk of complications, but residual tumor cells in the autograft may contribute to relapse. Development of methods for purging tumor cells that do not compromise the engraftment potential of the normal hematopoietic cells in the autograft has been a long-standing goal. Since primitive CML cells differentiate more rapidly in vitro than their normal counterparts and are also preferentially killed by mafosfamide and imatinib, we examined the purging effectiveness on CD34(+) CML cells using a strategy that combines a brief exposure to imatinib (0.5-1.0 microM for 72 h) and then mafosfamide (30-90 microg/ml for 30 min) followed by 2 weeks in culture with cytokines (100 ng/ml each of stem cell factor, granulocyte colony-stimulating factor and thrombopoietin). Treatment with 1.0 microM imatinib, 60 microg/ml mafosfamide and 14 days of culture with cytokines eliminated BCR-ABL(+) cells from chronic phase CML patient aphereses, while preserving normal progenitors. This novel purging strategy may offer a new approach to improving the effectiveness of autologous transplantation in imatinib-refractory CML patients.
...
PMID:A novel triple purge strategy for eliminating chronic myelogenous leukemia (CML) cells from autografts. 1643 11

With the development of fluorescence in situ hybridization (FISH), it was possible to detect the BCR-ABL fusion signal in both metaphase spreads and interphase cells of patients with chronic myeloid leukemia (CML). However, the use of FISH to detect residual disease in patients with CML post therapy was limited by the false positive rate using the early single fusion probes. Therefore, dual fusion probes that created a fusion signal on the derivative chromosome 9 in addition to the fusion sifnal on the Philadelphia chromosome or derivative chromosome 22 were developed. Using these second-generation probes, it was discovered that a significant proportion of CML cases has a sub-microscopic deletion at the site of the ABL-BCR fusion. This chapter outlines a testing strategy to identify deleltions of the derivative chromosome 9 and to use combinations of probes to identify residual disease in these cases.
...
PMID:Deletion of the derivative chromosome 9 in chronic myeloid leukemia. 1650 80

Chronic myeloid leukemia (CML) relapse after allogeneic stem cell transplantation (SCT) is a relatively frequent situation, which is correlated to disease status, time from diagnosis to transplant and T-cell depletion. We evaluated the potential for early minimal residual disease (MRD) BCR-ABL quantification to predict relapse of CML patients receiving allogeneic SCT. Minimal residual disease was analyzed by real-time quantitative reverse transcriptase-polymerase chain reaction (RQ-PCR) at day 100 (d100) in 38 patients with >1 year follow-up after conventional non-T-cell-depleted SCT. Normal ABL control values from 1724 follow-up blood samples were used to define an RQ-PCR amplifiability index and the limits of reliable use of BCR-ABL ratios. We then compared the 14 patients with a high-level d100 BCR-ABL/ABL ratio (> or = 10(-4)) to that of the 24 patients with a negative/low-level ratio (<10(-4)). Despite being comparable for all classical parameters, the incidence of relapse was significantly higher in the high MRD group (11/14 (79%)) compared to that of the low/negative MRD group (7/24 (29%)) (P = 0.009), with d100 MRD values representing an independent risk factor of relapse and disease-free survival, but not of overall survival, in multivariate analysis. These data should facilitate risk-adapted post-transplant immunosuppression and/or tyrosine kinase inhibitor therapy based on an early evaluation of MRD.
...
PMID:Prediction of relapse by day 100 BCR-ABL quantification after allogeneic stem cell transplantation for chronic myeloid leukemia. 1654 Nov 40

For immunotherapy of residual disease in patients with Philadelphia-positive leukemias, the BCR-ABL fusion regions are attractive disease-specific T-cell targets. We analyzed these regions for the prevalence of cytotoxic T lymphocyte (CTL) epitopes by an advanced reverse immunology procedure. Seventeen novel BCR-ABL fusion peptides were identified to bind efficiently to the human lymphocyte antigen (HLA)-A68, HLA-B51, HLA-B61 or HLA-Cw4 HLA class I molecules. Comprehensive enzymatic digestion analysis showed that 10 out of the 28 HLA class I binding fusion peptides were efficiently excised after their C-terminus by the proteasome, which is an essential requirement for efficient cell surface expression. Therefore, these peptides are prime vaccine candidates. The other peptides either completely lacked C-terminal liberation or were only inefficiently excised by the proteasome, rendering them inappropriate or less suitable for inclusion in a vaccine. CTL raised against the properly processed HLA-B61 epitope AEALQRPVA from the BCR-ABL e1a2 fusion region, expressed in acute lymphoblastic leukemia (ALL), specifically recognized ALL tumor cells, proving cell surface presentation of this epitope, its applicability for immunotherapy and underlining the accuracy of our epitope identification strategy. Our study provides a reliable basis for the selection of optimal peptides to be included in immunotherapeutic BCR-ABL vaccines against leukemia.
...
PMID:BCR-ABL fusion regions as a source of multiple leukemia-specific CD8+ T-cell epitopes. 1693 47

In the present study, we address the issue of the discontinuation of imatinib mesylate (Gleevec) in chronic myelogenous leukemia with undetectable residual disease for more than 2 years. Twelve patients were included. The median duration of real-time quantitative-polymerase chain reaction (RTQ-PCR) negativity and imatinib therapy were, respectively, 32 months (range, 24-46 months) and 45 months (range, 32-56 months) before imatinib interruption. Six patients displayed a molecular relapse with a detectable BCR-ABL transcript at 1, 1, 2, 3, 4, and 5 months. Imatinib was then reintroduced and led to a novel molecular response in most patients. Six other patients (50%) still have an undetectable level of BCR-ABL transcript after a median follow-up of 18 months (range, 9-24 months). We hypothesize that relapses observed within 6 months reflect the kinetics of undetectable dividing chronic myelogenous leukemia (CML) cells. Those cells may be eradicated or controlled in long-term nonrelapsing patients, as described in our study.
...
PMID:Imatinib mesylate discontinuation in patients with chronic myelogenous leukemia in complete molecular remission for more than 2 years. 1697 63

The JAK2-V617F mutation occurs in about 50% of patients with myelofibrosis and might be a reliable marker to monitor residual disease after allogeneic stem cell transplantation. We describe a new, highly sensitive (>or= 0.01%) real-time polymerase chain reaction (PCR) to monitor and quantify V617F-JAK2-positive cells after dose-reduced allogeneic stem cell transplantation. After 22 allogeneic stem cell transplantation procedures in 21 JAK2-positive patients with myelofibrosis, 78% became PCR negative. In 15 of 17 patients (88%), JAK2 remained negative after a median follow-up of 20 months. JAK2 negativity was achieved after a median of 89 days after allograft (range, 19-750 days). A significant inverse correlation was seen for JAK2 positivity and donor-cell chimerism (r:-0.91, P<.001). Four of 5 patients who never achieved JAK2 negativity fulfilled during the entire follow-up all criteria for complete remission recently proposed by the International Working Group, suggesting a major role for JAK2 measurement to determine depths of remission. In one case, residual JAK2-positive cells were successfully eliminated by donor lymphocyte infusion. In conclusion, allogeneic stem cell transplantation after dose-reduced conditioning induces high rates of molecular remission in JAK2-positive patients with myelofibrosis, and quantification of V617F-JAK2 mutation by real-time PCR allows the detection of minimal residual disease to guide adoptive immunotherapy.
...
PMID:Monitoring of the JAK2-V617F mutation by highly sensitive quantitative real-time PCR after allogeneic stem cell transplantation in patients with myelofibrosis. 1701 57

Chronic myelogenous leukaemia (CML) is characterised by a t(9;22)(q34;q11) translocation, which produces a fusion BCR-ABL protein with constitutive tyrosine kinase activity that is central to the pathogenesis of CML representing an ideal target for therapeutic intervention. Targeting BCR-ABL by imatinib has revolutionised the clinical course of CML. All patients in early chronic phase treated with imatinib achieve a complete haematological response, with 80-90% achieving a complete cytogenetic response. However, BCR-ABL transcripts remain detectable in the great majority of them, and approximately 16% chronic phase CML patients are resistant to or relapse after imatinib treatment, mainly through pre-existing or acquired point mutations in the binding pocket. Thus, other targeted approaches are being developed to overcome imatinib resistance. These include two novel tyrosine kinase inhibitors (nilotinib and dasatinib) that are producing clinical responses in different clinical settings, while other similar compounds are under evaluation in preclinical studies. Furthermore, additive immunotherapeutic strategies are emerging to synergise with imatinib in the elimination of molecular residual disease. This paper reviews the current details regarding these approaches and their developments.
...
PMID:Emerging drugs in chronic myelogenous leukaemia. 1706 24


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>

---