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)

BCR-ABL plays an essential role in the pathogenesis of chronic myeloid leukemia (CML) and some cases of acute lymphocytic leukemia (ALL). Although ABL kinase inhibitors have shown great promise in the treatment of CML, the persistence of residual disease and the occurrence of resistance have prompted investigations into the molecular effectors of BCR-ABL. Here, we show that BCR-ABL stimulates the proteasome-dependent degradation of members of the forkhead family of tumor suppressors in vitro, in an in vivo animal model, and in samples from patients with BCR-ABL-positive CML or ALL. As several downstream mediators of BCR-ABL are regulated by the proteasome degradation pathway, we also show that inhibition of this pathway, using bortezomib, causes regression of CML-like disease. Bortezomib treatment led to inhibition of BCR-ABL-induced suppression of FoxO proteins and their proapoptotic targets, tumor necrosis factor-related apoptosis-inducing ligand and BIM, thereby providing novel insights into the molecular effects of proteasome inhibitor therapy. We additionally show sensitivity of imatinib-resistant BCR-ABL T315I cells to bortezomib. Our data delineate the involvement of FoxO proteins in BCR-ABL-induced evasion of apoptosis and provide evidence that bortezomib is a candidate therapeutic in the treatment of BCR-ABL-induced leukemia.
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PMID:Proteasome inhibition causes regression of leukemia and abrogates BCR-ABL-induced evasion of apoptosis in part through regulation of forkhead tumor suppressors. 1965 5

This study was aimed to investigate the sensitivity and clinical application of interphase-dual-color and dual-fusion fluorescence in situ hybridization (DC-DF-FISH). The bcr/abl fusion gene was detected by FISH with dual-color and dual-fusion bcr/abl DNA probe in interphase cells of bone marrow from 1295 specimens. Retrospective analysis for the cases was performed by the means of conventional cytogenetic analysis (CCA) and FISH. The results indicated that in 1295 specimens from 539 patients, 456 specimens were positive involved in 310 patients, the karyotypes of 18 patients were normal, 5 patients failed to karyotyping analysis. About 75.5% (234/310) of positive patients displayed the typical DC-DF-FISH signal pattern, 76 patients showed atypical DC-DF-FISH signal patterns, 66 cases out of which showed variant signal, 16 patients displayed typical variant signals (1Y2G2R), 50 patients displayed deletion ABL and/or BCR signal. In 213 patients, the negative rate was 60% (128/213) after the treatment, 12 patients were sometimes negative and sometimes positive during the process of the treatment. It is concluded that DC-DF-FISH can be used to detect karyotypes with masked or variant Ph, gene deletion and minor residual disease (MRD) in process of treatment. The dual-color FISH technique is a much more sensitive and accurate tool for monitoring MRD and monitoring relapse, which is a necessary supplement to CCA.
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PMID:[Detection of bcr/abl fusion gene by dual color-dual fusion fluorescence in situ hybridization]. 1969 38

Translocation t(9;22), which produces the BCR-ABL gene, is pathognomonic of chronic myeloid leukemia. For clinical purposes, the amount of chimeric transcript is considered proportional to the leukemic clone; thus, mRNA is commonly used for molecular monitoring of patients. However, there is no consensus regarding the degree of increase in mRNA that should cause concern or whether the absence of transcript indicates a "cure." In this study, we analyzed 57 samples from 10 chronic myeloid leukemia patients undergoing imatinib treatment. For each sample, we compared BCR-ABL mRNA levels with the actual proportion of leukemic cells, which were measured through a novel genomic approach based on the quantitative amplification of DNA breakpoints. The two approaches gave similar patterns of residual disease, and the majority of patients were still positive after an average treatment period of 2 years. Nevertheless, in one of two patients with confirmed undetectable levels of chimeric transcript, DNA still revealed the persistence of leukemic cells at 42 months. These findings appear to justify the clinical practice of maintaining imatinib treatment indefinitely. However, the absence of leukemic DNA (observed in 1 of 10 patients) could be used to identify possible candidates for drug discontinuation. In conclusion, DNA analysis proved to be a reliable index of residual disease with potential applications in the field of clinical diagnostics and research.
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PMID:Molecular monitoring of residual disease in chronic myeloid leukemia by genomic DNA compared with conventional mRNA analysis. 1971 Apr

A series of DNA vaccines based on the bcr-abl fusion gene were developed and tested in mice. Two mouse (BALB/c) bcr-abl-transformed cell lines, B210 and 12B1, which both expressed p210bcr-abl and were oncogenic for syngeneic animals but differed in some other respects, were used as a model system. In the first series of experiments, plasmids carrying either the complete bcr-abl fusion gene or a fragment thereof coding for a 25-amino acid-long junction zone (bcr-abl25aa) linked with genes coding for a variety of immunostimulatory factors were used as the DNA vaccines. A plasmid carrying the complete bcr-abl gene was capable of inducing protection against challenge with either B210 or 12B1 cells. However, the DNA vaccines based on the gene fragment coding for p25aabcr-abl did not induce significant protection. To localize the immunizing epitopes on the p210bcr-abl protein, the whole fusion gene was split into nine overlapping fragments and these, individually or in various combinations, were used for immunization. Although none of the vaccines based on any single fragment provided potent protection, some combinations of these fragment-based vaccines were capable of eliciting protection comparable to that seen after immunization with the whole-gene vaccine. Surprisingly, a mixture of six fragment-vaccines was more immunogenic than the complete set of fragment DNA vaccines. To analyze this phenomenon, the three fragments missing from the hexavaccine were either individually or in various combinations mixed with the hexavaccine. The results obtained suggested that the product of the fragment coding for 197 amino acids forming the N-terminal of the BCR protein was involved in the decreased immunogenicity. However, further experiments are needed to clarify the point. Additional experiments revealed that all the important epitopes were located in the ABL portion of the p210bcr-abl protein. The livers, spleens and bone marrows of the successfully immunized animals were tested for the presence of bcr-abl-positive cells by RT-PCR. The results were negative, this suggesting that these animals were free of any residual disease.
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PMID:DNA vaccination against bcr-abl-positive cells in mice. 1972 31

Imatinib mesylate induces complete cytogenetic responses in patients with chronic myeloid leukemia (CML), yet many patients have detectable BCR-ABL transcripts in peripheral blood even after prolonged therapy. Bone marrow studies have shown that this residual disease resides within the stem cell compartment. Quiescence of leukemic stem cells has been suggested as a mechanism conferring insensitivity to imatinib, and exposure to the Granulocyte-Colony Stimulating Factor (G-CSF), together with imatinib, has led to a significant reduction in leukemic stem cells in vitro. In this paper, we design a novel mathematical model of stem cell quiescence to investigate the treatment response to imatinib and G-CSF. We find that the addition of G-CSF to an imatinib treatment protocol leads to observable effects only if the majority of leukemic stem cells are quiescent; otherwise it does not modulate the leukemic cell burden. The latter scenario is in agreement with clinical findings in a pilot study administering imatinib continuously or intermittently, with or without G-CSF (GIMI trial). Furthermore, our model predicts that the addition of G-CSF leads to a higher risk of resistance since it increases the production of cycling leukemic stem cells. Although the pilot study did not include enough patients to draw any conclusion with statistical significance, there were more cases of progression in the experimental arms as compared to continuous imatinib. Our results suggest that the additional use of G-CSF may be detrimental to patients in the clinic.
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PMID:Eradication of chronic myeloid leukemia stem cells: a novel mathematical model predicts no therapeutic benefit of adding G-CSF to imatinib. 1974 82

We report a case of a successful mobilization and harvest of the peripheral blood stem cells (PBSCs) in imatinib-pretreated and nilotinib treated 52-year-old woman diagnosed with Philadelphia chromosome-positive and BCR-ABL (b2a2) positive chronic phase CML in 2/2002. She failed interferon-alfa and imatinib treatment. She achieved her first complete molecular remission after 16 months of nilotinib treatment and later on was mobilized with filgrastim at a dose of 10 ug/kg/day applied subcutaneously once daily. The total number of 2.98 x 10(6) CD34+ cells/kg was harvested on the fourth day of the mobilization. The autologous graft of the stem cells was cryopreserved and tested for the residual disease: the FISH revealed negative results and the RT-PCR was positive (BCR-ABL/ABL ratio 0,0017 in RQ-PCR). To our knowledge, this is the first report of successful PBSC harvest in a patient significantly pretreated with imatinib and nilotinib.
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PMID:Successful peripheral blood stem cells collection in imatinib pretreated and nilotinib-treated chronic myeloid leukemia patient. 2022 40

Imatinib has revolutionized the treatment of chronic myelogenous leukemia (CML). Given the high rates of complete cytogenetic remission achieved with imatinib therapy, molecular monitoring of BCR-ABL transcript levels by real-time quantitative polymerase chain reaction has become the method of choice to assess the amount of residual disease below the cytogenetic threshold. BCR-ABL transcript levels measured at specific times during therapy may predict durable cytogenetic remission and prolonged progression-free survival or, on the contrary, failure and suboptimal response, thus directing clinical decisions. Recently, recommendations have been established for harmonizing the methodologies used to measure BCR-ABL transcripts in patients with CML, allowing results to be expressed on a standardized comparable international scale. Rising levels of BCR-ABL transcripts indicate the need for an analysis of kinase mutations, the major mechanism of imatinib resistance. The early detection and the characterization of these mutations may allow timely and appropriate treatment to overcome resistance.
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PMID:Molecular monitoring in patients with chronic myelogenous leukemia. 2042 49

It is not clear if absence of BCR-ABL transcripts--complete molecular response (CMR)--is synonymous with, or required for, cure of chronic myeloid leukemia (CML). Some patients achieve CMR with imatinib (IM), but most relapse shortly after treatment discontinuation. Furthermore, most patients in long-term remission (LTR) post-stem cell transplantation (SCT) are considered functionally cured, although some remain occasionally positive for low-level BCR-ABL mRNA. Interpretation of the latter is complicated because it has been observed in healthy subjects. We designed a patient-specific, highly sensitive, DNA quantitative polymerase chain reaction to test follow-up samples for the original leukemic clone, identified by its unique genomic BCR-ABL fusion (gBCR-ABL). In 5 IM-treated patients in CMR, gBCR-ABL was detected in transcript-negative samples; 4 patients became gBCR-ABL-negative with continuing IM therapy. In contrast, of 9 patients in LTR (13-27 years) post-SCT, gBCR-ABL was detected in only 1, despite occasional transcript-positive samples in 8 of them. In conclusion, in IM-treated patients, absence of transcripts should not be interpreted as absence of the leukemic clone, although continuing IM after achievement of CMR may lead to further reduction of residual disease. Post-SCT, we found little evidence that the transcripts occasionally detected originate from the leukemic clone.
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PMID:In search of the original leukemic clone in chronic myeloid leukemia patients in complete molecular remission after stem cell transplantation or imatinib. 2079 40

Chronic Myeloid Leukemia (CML) is a clonal disease characterized by the presence of the Philadelphia (Ph+) chromosome and its oncogenic product, BCR-ABL, a constitutively active tyrosine kinase, that is present in >90% of the patients. Epidemiologic data indicates that almost 5000 new cases are reported every year and 10% of these patients eventually succumb to the disease. The treatment of CML was revolutionized by the introduction of imatinib mesylate (IM, Gleevec), a BCR-ABL tyrosine kinase inhibitor (TKI). The clinical use of specific BCR-ABL inhibitors has resulted in a significantly improved prognosis, response rate, overall survival, and patient outcome in CML patients compared to previous therapeutic regimens. However, the complete eradication of CML in patients receiving imatinib was limited by the emergence of resistance mostly due to mutations in the ABL kinase domain and to a lesser extent by molecular residual disease after treatment. The second-generation BCR-ABL TKIs nilotinib (Tasigna) and dasatinib (Sprycel), showed significant activity in clinical trials in patients intolerant or resistant to imatinib therapy, except in those patients with the T315I BCR-ABL mutation. Identifying key components involved in the CML pathogenesis may lead to the exploration of new approaches that might eventually overcome resistance mediated to the BCR-ABL TKIs. Here, we present an overview about the current treatment of Ph+ CML patients with the TKIs and the obstacles to successful treatment with these drugs.
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PMID:BCR-ABL tyrosine kinase inhibitors in the treatment of Philadelphia chromosome positive chronic myeloid leukemia: a review. 2053 86

How to treat CML patients who are resistant to inhibitors of BCR-ABL tyrosine kinase such as Imatinib is a very important and urgent issue in clinical hematology. Here, we report a case of Imatinib-treated CML in which intradermally administered WT1 peptide vaccine elicited WT1-specific immune responses and the resultant reduction in the persistent residual disease in co-administration of Imatinib. BCR-ABL mRNA levels were being maintained under the detection limit for 8 months since week 77 of vaccination. No adverse effects except local erythema at the injection sites were observed. The tetramer assay revealed that the decrease in BCR-ABL mRNA levels was associated with the increase in frequency of WT1-specific cytotoxic T lymphocytes, notably effector-memory type of that, in the patient's peripheral blood. The case presented here indicates that WT1 peptide vaccine may become a safe and cure-oriented therapy for CML patients who have residual disease regardless of the treatment with Imatinib.
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PMID:WT1 peptide vaccine induces reduction in minimal residual disease in an Imatinib-treated CML patient. 2063 41


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