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)

Acquired constitutive activation of protein tyrosine kinases is a central feature in the pathogenesis of chronic myeloproliferative disorders (CMPDs). The most commonly involved genes are the receptor tyrosine kinases PDGFRA, PDGFRB, FGFR1 or c-KIT and the non-receptor tyrosine kinases JAK2 and ABL. Activation occurs as a consequence of specific point mutations or fusion genes generated by chromosomal translocations, insertions or deletions. Mutant kinases are constitutively active in the absence of the natural ligands resulting in deregulation of haemopoiesis in a manner analogous to BCR-ABL in chronic myeloid leukaemia. With the advent of targeted signal transduction therapy with tyrosine kinase inhibitors, an accurate diagnosis of CMPDs by morphology, karyotyping and molecular genetics has become increasingly important. Imatinib induces high response rates in patients associated with constitutive activation of ABL, PDGFRalpha, PDGFRbeta and some KIT mutants. Other inhibitors under development are promising candidates for effective treatment of patients with constitutive activation of JAK2, FGFR1 and imatinib-resistant KIT mutants.
 ...
PMID:Tyrosine kinases as therapeutic targets in BCR-ABL negative chronic myeloproliferative disorders. 1730 99

Myeloproliferative disorders (MPDs) constitute a group of hematopoietic malignancies that feature enhanced proliferation and survival of one or more myeloid lineage cells. William Dameshek is credited for introducing the term "MPDs" in 1951 when he used it to group chronic myeloid leukemia (CML), polycythemia vera (PV), essential thrombocythemia (ET) and primary myelofibrosis (PMF) under one clinicopathologic category. Since then, other myeloid neoplasms have been added to the MPD member list: chronic neutrophilic (CNL), eosinophilic (CEL) and myelomonocytic (CMML) leukemias; juvenile myelomonocytic leukemia (JMML); hypereosinophilic syndrome (HES); systemic mastocytosis (SM); and others. Collectively, MPDs are stem cell-derived clonal proliferative diseases whose shared and diverse phenotypic characteristics can be attributed to dysregulated signal transduction--a consequence of acquired somatic mutations. The most recognized among the latter is BCR-ABL, the disease-causing mutation in CML. Other mutations of putative pathogenetic relevance in MPDs include: JAK2V617F in PV, ET, and PMF; JAK2 exon 12 mutations in PV; MPLW515L/K in PMF and ET; KITD816V in SM; FIP1L1-PDGFRA in CEL-SM; rearrangements of PDGFRB in CEL-CMML and FGFR1 in stem cell leukemia-lymphoma syndrome; and RAS/PTPN11/NF1 mutations in JMML. This increasing repertoire of mutant molecules has streamlined translational research and molecularly targeted drug development in MPDs.
 ...
PMID:Oncogenes in myeloproliferative disorders. 1735 42

We have investigated the hypothesis that constitutional genetic variation in IL-5 signalling may be associated with the development or severity of FIP1L1-PDGFRA-positive chronic eosinophilic leukaemia (CEL) in humans. We genotyped six single-nucleotide polymorphisms (SNP) within or close to the IL5RA or IL5 genes in 82 patients with FIP1L1-PDGFRA-positive CEL plus, as controls, healthy individuals (n=100), patients with FIP1L1-PDGFRA-negative eosinophilia (n=100) or patients with chronic myeloid leukaemia (CML) (n=100). We found no association between SNP allele frequency between FIP1L1-PDGFRA-positive and control cases. However, for FIP1L1-PDGFRA cases, we found an association between the genotype at rs4054760, an SNP in the 5'-UTR of IL5RA and peripheral blood eosinophil count (P=0.026) as well as the presence or absence of tissue infiltration (P=0.032). Although these associations fell below the level of significance once corrected for multiple testing, no such association was seen in FIP1L1-PDGFRA-negative cases and no difference in allele frequencies for rs4054760 was seen in control populations across Europe. Furthermore, in an analysis of 112 patients with CML, IL5RA expression was strongly related to rs4054760 genotype (P<0.001). These data suggest that the variations in IL5RA expression are linked to constitutional IL5RA genotype and severity of FIP1L1-PDGFRA disease.
 ...
PMID:The severity of FIP1L1-PDGFRA-positive chronic eosinophilic leukaemia is associated with polymorphic variation at the IL5RA locus. 1791 8

Recent years showed significant progress in the molecular characterization of the chronic myeloproliferative disorders (CMPD) which are classified according to the WHO classification of 2001 as polycythemia vera (PV), chronic idiopathic myelofibrosis (CIMF), essential thrombocythemia (ET), CMPD/unclassifiable (CMPD-U), chronic neutrophilic leukemia, and chronic eosinophilic leukemia (CEL)/hypereosinophilic syndrome, all to be delineated from BCR/ABL-positive chronic myeloid leukemia (CML). After 2001, the detection of the high frequency of the JAK2V617F mutation in PV, CIMF, and ET, and of the FIP1L1-PDGFRA fusion gene in CEL further added important information in the diagnosis of CMPD. These findings also enhanced the importance of tyrosine kinase mutations in CMPD and paved the way to a more detailed classification and to an improved definition of prognosis using also novel minimal residual disease (MRD) markers. Simultaneously, the broadening of therapeutic strategies in the CMPD, e.g., due to reduced intensity conditioning in allogeneic hematopoietic stem cell transplantation and the introduction of tyrosine kinase inhibitors in CML, in CEL, and in other ABL and PDGRFB rearrangements, increased the demands to diagnostics. Therefore, today, a multimodal diagnostic approach combining cytomorphology, cytogenetics, and individual molecular methods is needed in BCR/ABL-negative CMPD. A stringent diagnostic algorithm for characterization, choice of treatment, and monitoring of MRD will be proposed in this review.
 ...
PMID:The diagnosis of BCR/ABL-negative chronic myeloproliferative diseases (CMPD): a comprehensive approach based on morphology, cytogenetics, and molecular markers. 1793 25

Chronic myeloid leukaemia (CML) is a molecularly defined disease. The BCR-ABL fusion occurs in all cases of classical CML and leukaemic cells express a constitutively activated BCR-ABL tyrosine kinase. Other fusion oncogenes involving tyrosine kinases, including ABL and PDGFRA/B, have been identified, and are associated with leukaemic syndromes that may resemble CML. The discovery and treatment of these related disorders has been facilitated by our detailed understanding of CML. Imatinib mesylate has significantly improved the outcome of patients with CML, but there remains a significant minority of chronic phase CML patients for whom the response to treatment with standard dose imatinib is suboptimal. Cytogenetic and molecular monitoring of the response to treatment provides important prognostic information. Achievement of a major molecular response (MMR) in chronic phase patients treated de novo with imatinib confers near 100% freedom from progression to advanced phase, and MMR is now an important goal of therapy. Standardisation of BCR-ABL molecular monitoring is under way and should enable the accurate and reproducible identification of MMR in laboratories around the world. Point mutations in the kinase domain of BCR-ABL are the most common cause of acquired resistance to imatinib treatment. The susceptibility of a mutation to imatinib, nilotinib, or dasatinib may help to guide changes in therapy in a patient with resistance. In addition to these established methods of monitoring, there are new tests in development that may assist in determining prognosis and optimising therapy. Among patients receiving the same dose of imatinib, the plasma level of imatinib shows considerable inter-patient variation, and there is emerging evidence that higher levels may be associated with improved response to treatment. The intracellular concentration of imatinib also shows considerable variation, most likely related to differences in influx and efflux transport mechanisms. We discuss how these established and emerging assays might be used to optimise the treatment of CML patients.
 ...
PMID:Current and emerging tests for the laboratory monitoring of chronic myeloid leukaemia and related disorders. 1842 43

Gastrointestinal stromal tumors (GIST) are rare tumors of mesenchymal origin that may arise anywhere along the gastrointestinal tract or in the peritoneum. In most cases, GIST harbor mutations of KIT or PDGFRA. Imatinib mesylate (IM), a small-molecule tyrosine kinase inhibitor developed for the treatment of chronic myeloid leukemia, has been shown to be active against these mutations and has significant activity in patients with metastatic GIST. However, resistance to IM emerges after a median of 24 months of treatment. Sunitinib malate (SU) has been approved for the treatment of patients with IM-resistant advanced GIST, but the median progression-free survival in this setting is only 6 months. This article reviews the current knowledge regarding IM and SU resistance in GIST, as well as the available options for the management of GIST resistant to IM and SU.
 ...
PMID:Novel approaches to gastrointestinal stromal tumors resistant to imatinib and sunitinib. 1900 10

Therapeutically validated oncoproteins in myeloproliferative neoplasms (MPNs) include BCR-ABL in chronic myelogenous leukemia (CML) and a spectrum of PDGFRA/B mutant proteins that are products of intra- (eg, FIP1L1-PDGFRA) or interchromosomal (eg, ETV6-PDGFRB) gene fusions. Other MPN-relevant putative oncogenes that are awaiting therapeutic validation, include JAK2 and MPL mutations in polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (PMF); KITD816V and other KIT mutations in systemic mastocytosis, and FGFR1 rearrangements associated with the 8p11 leukemia/lymphoma syndrome. The current review focuses on mutant molecules of interest in classic MPNs (ie, CML, PV, ET, and PMF) in the context of their value as drug targets.
 ...
PMID:Oncogenic signals as treatment targets in classic myeloproliferative neoplasms. 1914 89

The tyrosine kinase (TK) inhibitor, imatinib, has revolutionized therapy of malignancies that are addicted to one of its target kinases, c-abl, c-kit and PDGF-R. This addiction is generally dependent on the acquisition of an activating kinase mutation, e.g., the bcr-abl fusion gene in chronic myeloid leukemia, or point mutations of KIT or PDGFRA in gastrointestinal stroma tumors (GIST). Other types of sarcomas are generally considered to be insensitive to imatinib. We have observed a striking and durable remission of an advanced angiosarcoma to imatinib that can only be explained by TK addiction. Unexpectedly, GIST-type KIT and PDGFRA mutations were absent in this case. This case illustrates the diagnostic challenges in identifying individual candidate patients for TK inhibitor therapy.
 ...
PMID:Dramatic and durable efficacy of imatinib in an advanced angiosarcoma without detectable KIT and PDGFRA mutations. 1918 35

Eosinophilia is a recurrent feature and diagnostic clue in several hematologic malignancies. In stem cell- and myelopoietic neoplasms, eosinophils are derived from the malignant clone, whereas in lymphoid neoplasms and reactive states, eosinophilia is usually triggered by eosinopoietic cytokines. Myeloid neoplasms typically presenting with eosinophilia include chronic myeloid leukemia, chronic eosinophilic leukemia (CEL), other myeloproliferative neoplasms, some acute leukemias, advanced mast cell disorders, and rare forms of myelodysplastic syndromes. Diagnostic evaluations in unexplained eosinophilia have to take these diagnoses into account. In such patients, a thorough hematologic work-up including bone marrow histology and immunohistochemistry, cytogenetics, molecular markers, and a complete staging of potentially affected organ systems has to be initiated. Endomyocardial fibrosis, the most dangerous cardiovascular complication of the hypereosinophilic state, is frequently detected in PDGFR-mutated neoplasms, specifically in FIP1L1/PDGFRA+ CEL, but is usually not seen in other myeloid neoplasms or reactive eosinophilia, even if eosinophilia is recorded for many years. Treatment of hypereosinophilic patients depends on the variant of disease, presence of end organ damage, molecular targets, and the overall situation in each case. In a group of patients, oncogenic tyrosine kinases (TK) such as FIP1L1/PDGFRA, can be employed as therapeutic targets by using imatinib or other TK-blocking agents.
 ...
PMID:Pathogenesis, classification, and therapy of eosinophilia and eosinophil disorders. 1924 39

Platelet-derived growth factor (PDGF) receptors (PDGFR) and their ligands play critical roles in several human malignancies. Sunitinib is a clinically approved multitargeted tyrosine kinase inhibitor that inhibits vascular endothelial growth factor receptor, c-KIT, and PDGFR, and has shown clinical activity in various solid tumors. Activation of PDGFR signaling has been described in gastrointestinal stromal tumors (PDGFRA mutations) as well as in chronic myeloid leukemia (BCR-PDGFRA translocation), and sunitinib can yield clinical benefit in both settings. However, the discovery of PDGFR activating mutations or gene rearrangements in other tumor types could reveal additional patient populations who might benefit from treatment with anti-PDGFR therapies, such as sunitinib. Using a high-throughput cancer cell line screening platform, we found that only 2 of 637 tested human tumor-derived cell lines show significant sensitivity to single-agent sunitinib exposure. These two cell lines [a non-small-cell lung cancer (NSCLC) and a rhabdomyosarcoma] showed expression of highly phosphorylated PDGFRA. In the sunitinib-sensitive adenosquamous NSCLC cell line, PDGFRA expression was associated with focal PFGRA gene amplification, which was similarly detected in a small fraction of squamous cell NSCLC primary tumor specimens. Moreover, in this NSCLC cell line, focal amplification of the gene encoding the PDGFR ligand PDGFC was also detected, and silencing PDGFRA or PDGFC expression by RNA interference inhibited proliferation. A similar codependency on PDGFRA and PDGFC was observed in the sunitinib-sensitive rhabdomyosarcoma cell line. These findings suggest that, in addition to gastrointestinal stromal tumors, rare tumors that show PDGFC-mediated PDGFRA activation may also be clinically responsive to pharmacologic PDGFRA or PDGFC inhibition.
 ...
PMID:Ligand-dependent platelet-derived growth factor receptor (PDGFR)-alpha activation sensitizes rare lung cancer and sarcoma cells to PDGFR kinase inhibitors. 1936 96


<< Previous 1 2 3 4 5 Next >>