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)

A retrospective comparison of WT1 and BCR-ABL1 expression was performed in 40 imatinib-treated chronic myeloid leukaemia patients. The overall correlation of WT1 and BCR-ABL1 was low. In two patients WT1 expression was increasing despite very low BCR-ABL1 levels. As both revealed Ph-negative aberrant clones, a second independent cohort of 20 cases, all with Ph-negative clonal evolution, was analysed. High WT1 expression (5.0-177.0%) was detected in a case with +11 and in four of eight cases with +8, but not in cases with del(20q) or -Y. Thus, increasing WT1 levels in molecular responders may indicate Ph-negative clonal cytogenetic evolution during imatinib treatment.
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PMID:RQ-PCR based WT1 expression in comparison to BCR-ABL quantification can predict Philadelphia negative clonal evolution in patients with imatinib-treated chronic myeloid leukaemia. 1962 38

A subset of patients with chronic myeloid leukemia (CML) who receive imatinib therapy will require alternative therapy at some point owing to safety reasons or lack of efficacy. Achieving an early response with imatinib is protective against treatment failure; second-generation tyrosine kinase inhibitors (TKIs; for example, nilotinib, dasatinib, bosutinib), however, have proven to be efficacious at restoring cytogenetic responses in patients who require subsequent therapy. Response duration, however, is yet to be established and a considerable proportion of patients fail to achieve a clinically meaningful response. A third generation of TKIs is currently undergoing clinical testing for use in patients who fail imatinib and a second-generation TKI. Most of these agents are multikinase inhibitors with activity against a wide variety of BCR-ABL1 mutations, including the highly resistant T315I. The use of second-generation TKIs in the frontline setting seems to provide higher rates of early response compared with imatinib. If these results are confirmed in randomized studies, nilotinib and dasatinib could replace imatinib as standard frontline therapy in CML. Despite the activity of all of the above mentioned agents, curing CML will ultimately depend on the development of agents capable of vanquishing BCR-ABL1-positive CML stem cells. Efforts aimed at achieving this goal are ongoing.
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PMID:Imatinib and beyond--exploring the full potential of targeted therapy for CML. 1965 54

The development of Imatinib Mesylate (IM), the first specific inhibitor of BCR-ABL1, has had a major impact in patients with Chronic Myeloid Leukemia (CML), establishing IM as the standard therapy for CML. Despite the clinical success obtained with the use of IM, primary resistance to IM and molecular evidence of persistent disease has been observed in 20-25% of IM treated patients. The existence of second generation TK inhibitors, which are effective in patients with IM resistance, makes identification of predictors of resistance to IM an important goal in CML. In this study, we have identified a group of 19 miRNAs that may predict clinical resistance to IM in patients with newly diagnosed CML.
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PMID:MicroRNA expression profiling in Imatinib-resistant Chronic Myeloid Leukemia patients without clinically significant ABL1-mutations. 1972 6

Chronic myeloid leukemia (CML) is induced by BCR-ABL1 and can be effectively treated for many years with Imatinib until leukemia cells acquire drug resistance through BCR-ABL1 mutations and progress into fatal B lymphoid blast crisis (LBC). Despite its clinical significance, the mechanism of progression into LBC is unknown. Here, we show that LBC but not CML cells express the B cell-specific mutator enzyme AID. We demonstrate that AID expression in CML cells promotes overall genetic instability by hypermutation of tumor suppressor and DNA repair genes. Importantly, our data uncover a causative role of AID activity in the acquisition of BCR-ABL1 mutations leading to Imatinib resistance, thus providing a rationale for the rapid development of drug resistance and blast crisis progression.
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PMID:The B cell mutator AID promotes B lymphoid blast crisis and drug resistance in chronic myeloid leukemia. 1973 15

The 2008 WHO classification system for hematological malignancies is comprehensive and includes histology and genetic information. Myeloid neoplasms are now classified into five categories: acute myeloid leukemia, myelodysplastic syndromes (MDS), myeloproliferative neoplasms (MPN), MDS/MPN, and myeloid and/or lymphoid malignancies associated with eosinophilia and PDGFR or FGFR1 rearrangements. MPN are subclassified into eight separate entities: chronic myelogenous leukemia, polycythemia vera, essential thrombocythemia, primary myelofibrosis, systemic mastocytosis, chronic eosinophilic leukemia not otherwise specified, chronic neutrophilic leukemia, and unclassifiable MPN. The diagnosis of chronic myelogenous leukemia requires the presence of BCR-ABL1, while its absence is required for all other MPN. Additional MPN-associated molecular markers include mutations of JAK2, MPL, TET2 and KIT. JAK2 V617F is found in most patients with polycythemia vera, essential thrombocythemia, or primary myelofibrosis and is, therefore, useful as a clonal marker in those settings. The diagnostic utility of MPL and TET2 mutations is limited by low mutational frequency. In systemic mastocytosis, presence of KIT D816V is expected but not essential for diagnosis. Chronic eosinophilic leukemia not otherwise specified should be distinguished from both PDGFR-rearranged or FGFR1-rearranged neoplasms and hypereosinophilic syndrome. We discuss histologic, cytogenetic and molecular changes in MPN and illustrate their integration into practical diagnostic algorithms.
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PMID:Myeloproliferative neoplasms: contemporary diagnosis using histology and genetics. 1980 46

Chronic myeloid leukemia (CML) is a paradigm for neoplasias that are defined by a unique genetic aberration, the BCR-ABL1 fusion gene. CML is also the best example for molecular target therapy. The development of protein tyrosine kinase inhibitor, imatinib, has entirely changed the strategy of therapy for CML. Nonetheless, many fields of pathogenesis for CML have not been elucidated, such as the mechanisms of blastic crisis, the causes of genetic instability including the inactivation of tumor suppressor genes, and oncogenic signaling pathways downstreams of the BCR-ABL1 fusion gene product. Herein, we review current knowledge on the molecular pathogenesis of CML.
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PMID:[Molecular pathogenesis of chronic myeloid leukemia]. 1986 Jan 86

The discovery of molecularly targeted agents that selectively inhibit bcr-abl tyrosine kinase activity, such as imatinib, has revolutionized the treatment and natural history of chronic myelogenous leukemia (CML). Treatment of chronic-phase CML with imatinib showed complete cytogenetic response rates of more than 40% in patients after failure of interferon-alpha, and more than 80% in patients with newly diagnosed CML. Patients with CML can now expect excellent long-term survival, often without major side effects. In most patients, however, residual leukemic burden remains detectable using a sensitive reverse transcription-polymerase chain reaction method. In addition, many patients undergoing imatinib therapy will either not respond or lose their response over time because of resistance or intolerance. The introduction of second-generation tyrosine kinase inhibitors (TKIs) re-establishes response in approximately half of these patients. Several agents are being developed for treating patients who experience suboptimal response to second-generation TKIs and for those who develop resistance caused by the emergence of highly resistant BCR-ABL1 mutations. This article provides an overview of novel targeted agents available for CML.
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PMID:New agents in the treatment of chronic myelogenous leukemia. 1987 42

Little important progress was made in terms of prolongation of life for patients with chronic myeloid leukaemia (CML) until the advent of interferon-alpha and allogeneic stem cell transplantation in the 1980s. However, in 1998 the introduction of imatinib, the first tyrosine kinase inhibitor (TKI) that specifically targets the BCR-ABL1 oncoprotein, has fundamentally altered treatment strategies for patients in all phases of CML. Imatinib is now recommended as initial treatment for all patients who present in chronic phase (CP) and about two-thirds of patients so treated will be in continuing complete cytogenetic response 7 or more years after starting therapy. A small proportion of these patients can stop the drug without molecular evidence of relapse. For the minority of patients who are judged to have failed initial treatment with imatinib at standard dosage or increased dosage, the use of second-generation TKI or allogeneic stem cell transplantation must be considered.
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PMID:Treatment strategies for CML. 1995 82

To elucidate whether tyrosine kinase inhibitor (TKI) resistance in chronic myeloid leukemia is associated with characteristic genomic alterations, we analyzed DNA samples from 45 TKI-resistant chronic myeloid leukemia patients with 250K single nucleotide polymorphism arrays. From 20 patients, matched serial samples of pretreatment and TKI resistance time points were available. Eleven of the 45 TKI-resistant patients had mutations of BCR-ABL1, including 2 T315I mutations. Besides known TKI resistance-associated genomic lesions, such as duplication of the BCR-ABL1 gene (n = 8) and trisomy 8 (n = 3), recurrent submicroscopic alterations, including acquired uniparental disomy, were detectable on chromosomes 1, 8, 9, 17, 19, and 22. On chromosome 22, newly acquired and recurrent deletions of the IGLC1 locus were detected in 3 patients, who had previously presented with lymphoid or myeloid blast crisis. This may support a hypothesis of TKI-induced selection of subclones differentiating into immature B-cell progenitors as a mechanism of disease progression and evasion of TKI sensitivity.
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PMID:SNP array analysis of tyrosine kinase inhibitor-resistant chronic myeloid leukemia identifies heterogeneous secondary genomic alterations. 1996 45

Molecular monitoring of the BCR-ABL1 transcript in chronic myelogenous leukemia (CML) using quantitative real-time PCR (RQ-PCR) can be performed using either bone marrow (BM) or peripheral blood (PB). However, a recent report by Stock et al. [International Journal of Oncology 28 (2006) 1099] questioned the reliability of PB samples for BCR-ABL1 detection as performed by RQ-PCR. We report a study on 114 CML patients who received allogeneic stem cell transplantation (ASCT), and who were monitored by RQ-PCR using paired samples of BM and PB: the total number of determinations was 428, with a median follow-up after transplant of 8 years. BCR-ABL1 transcript was undetectable or <0.1%, in 106 (49.57%) and 62 (29%) paired determinations, respectively. BCR-ABL1 was >0.1% in 36 (16.8%) paired determinations and was discordant in 10 (4.7%). Agreement between PB and BM results was quantified by the kappa test (k = 0.85; 95% CI 0.76-0.94). This study shows that BCR-ABL1 RQ-PCR monitoring of CML patients after ASCT with PB is concordant with BM in 95.3% of cases, and thus may be used to monitor the disease. This may be relevant when discussing both quality of life issues and the need for post-transplant monitoring with the patient.
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PMID:Peripheral blood vs. bone marrow for molecular monitoring of BCR-ABL1 levels in chronic myelogenous leukemia, a retrospective analysis in allogeneic bone marrow recipients. 1996 20


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