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

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Query: UMLS:C0023418 (leukemia)
93,477 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

BCR/ABL has a causal role in Philadelphia (Ph)-chromosome positive leukemia. The SH2/SH3 adapter protein CRKL is a major substrate of the deregulated BCR/ABL tyrosine kinase and is aberrantly tyrosine-phosphorylated in Ph-positive leukemia cells. In this study, experiments were pursued to identify and analyse the CRKL phosphorylation site(s). In an in vitro kinase assay, CRKL phosphorylation by the abl kinase was limited to a small region between the two CRKL SH3 domains. Within this region, mutation of tyrosine residue 207 yielded a mutant CRKL which could not be phosphorylated by BCR/ABL. Stable overexpression of CRKL or CRKL-Y207F did not transform NIH3T3 cells, while the Y207F mutation eliminated tyrosine-phosphorylation of CRKL. These studies indicate that Y207 in CRKL represents the major in vivo phosphorylation site. Phosphorylation of Y207 provides a binding site for the CRKL SH2 domain and potentially for other SH2-containing proteins. The Y207F mutation in CRKL did not enhance or decrease association with various target signalling proteins, including SOS or C3G, which interact specifically with the CRKL N-SH3 domain. These findings suggest that complex formation with cellular targets is not modulated by CRKL tyrosine-phosphorylation.
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PMID:Tyrosine 207 in CRKL is the BCR/ABL phosphorylation site. 905 48

Using a reverse transcription-polymerase chain reaction (RT-PCR), we identified a patient with typical clinical features of chronic myelogenous leukaemia (CML) in the chronic phase who showed no amplification of the CML-type BCR/ABL transcript. RT-PCR with primers detecting the acute lymphoid leukaemia (ALL)-type transcript disclosed a novel fragment co-amplified with an ALL-type fragment. Sequencing revealed the novel transcript to be a chimaeric mRNA produced by fusion of a segment of BCR exon 2 (e2) to ABL exon 2 (a2), with a 21 base-pair insertion of ABL intron 1b sequence between them. This transcript has not been reported previously.
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PMID:A novel acute lymphoid leukaemia type BCR/ABL transcript in chronic myelogenous leukaemia. 905 70

The Philadelphia chromosome translocation generates a chimeric oncogene, BCR/ABL, which causes chronic myelogenous leukemia (CML). In primary leukemic neutrophils from patients with CML, the major tyrosine phosphorylated protein is CRKL, an SH2-SH3-SH3 adapter protein which has an overall homology of 60% to CRK, the human homologue of the v-crk oncogene. In cell lines transformed by BCR/ABL, CRKL was tyrosine phosphorylated, while CRK was not. We looked for changes in CRK- and CRKL-binding proteins in Ba/F3 hematopoietic cell lines which were transformed by BCR/ABL. Anti-CRK II or anti-CRKL immunoprecipitates were probed by far Western blotting with CRK II- or CRKL-GST fusion proteins to display CRK- and CRKL-coprecipitating proteins. There was a striking qualitative difference in the proteins coprecipitating with CRKL and CRK II. In untransformed cells, three major proteins coprecipitated with CRKL, identified as C3G, SOS and c-ABL. Each of these proteins was found to interact with the CRKL-SH3 domains, but not the SH2 domain. After BCR/ABL transformation, the CRKL SH3-domain binding proteins did not change, with the exception that BCR/ABL now coprecipitated with CRKL. Compared to CRKL, very few proteins coprecipitated with CRK II in untransformed, quiescent cells. After BCR/ABL transformation, both the CRKL- and CRK-SH2 domains bound to a new complex of proteins of approximate molecular weight 105-120 kDa. The major protein in this complex was identified as p120CBL. Thus, in these hematopoietic cell lines, CRKL is involved to a greater extent than CRK II in normal signaling pathways that involve c-ABL, C3G and SOS. In BCR/ABL-transformed cells, CRKL but not CRK II, appears to form complexes which potentially link BCR/ABL, c-ABL, C3G, and SOS to the protooncoprotein, p120CBL.
Leukemia 1997 Mar
PMID:The BCR/ABL oncogene alters interaction of the adapter proteins CRKL and CRK with cellular proteins. 906 77

Fluorescence in situ hybridization (FISH) and the reverse transcription-polymerase chain reaction (RT-PCR) were used to examine a patient presenting with acute myelogenous leukemia (AML) FAB M2, and a complex t(4;9;22)(p14;q34;q11.2). The patient's clinical course was characterized by an aggressive leukemia, resistant to intensive therapy including allogeneic bone marrow transplantation. FISH analysis, using two chromosome painting probes and a BCR/ABL specific probe, confirmed the cytogenetic observation of a 22q11.2-->4p14 and a 4p14-->9q34 exchange, and revealed the presence of a 9q34-->22q11.2, respectively. In addition, RT-PCR demonstrated the presence of a BCR/ABL transcript derived from the major breakpoint cluster region (M-bcr) of the BCR gene. This transcript has been shown to generate an active 210 kDa tyrosine kinase protein more commonly observed in chronic myelogenous leukemia. Because the presentation of AML with this ABL-->BCR fusion product is a rare event, it would seem likely that the additional complex chromosomal rearrangement involving chromosomes 4, 9, and 22 played a role in the aggressive presentation and clinical behavior of this patient's leukemia.
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PMID:Complex chromosome 4, 9, and 22 rearrangement in a patient presenting with AML-FAB M2. 907 96

Manipulation of autologous bone marrow cells (BM) for transplantation in chronic myeloid leukemia (CML) to enrich for normal cells is a novel approach that may improve survival for patients not suitable for allogeneic transplantation. Limitations of this technique include the reported low frequency of normal stem cells in CML and the difficulties in obtaining sufficient BM for manipulation. To address these problems we compared the apheresis product with the diagnostic bone marrow at diagnosis as a source of primitive BCR/ABL-negative progenitors. We analyzed the CD34+ HLA-DR- and CD34+CD38(-) populations in five CML patients to evaluate the frequency of BCR-ABL-negative progenitors and pre-progenitors in these populations. Progenitor analysis was performed by RT-PCR of individual hemopoietic colonies from a standard CFU-GM assay. Analysis of pre-progenitors involved RT-PCR of secondary colonies derived from a stroma-free pre-CFU assay. Our results show variable levels of BCR-ABL-negative progenitors in the 34+DR- population but very low levels of BCR-ABL-negative progenitors in the 34+38- population in blood. Analysis of pre-progenitors from the 34+DR- fraction of peripheral blood (PB) and BM showed 80-100% and 85-100% of colonies were BCR-ABL negative at days 14 and 28, respectively. Analysis of pre-progenitors from the 34+38- fraction of PB and BM showed 23-100% and 42-100% of colonies were BCR-ABL negative at days 14 and 28, respectively. In summary, pre-progenitors from the 34+DR- and 34+38- populations are predominantly BCR-ABL negative in both marrow and blood at diagnosis. Apheresis product collected at diagnosis is a more abundant sources of BCR-ABL-negative pre-progenitors than BM. Thus, apheresis product could potentially be utilized as a source of BCR-ABL-negative stem cells in CML.
Leukemia 1997 Apr
PMID:Peripheral blood is a source of BCR-ABL-negative pre-progenitors in early chronic phase chronic myeloid leukemia. 909 99

The molecular genetic basis of chronic myeloid leukemia (CML) is well-defined, but until recently therapeutic approaches have been largely empiric. Conventional chemotherapy and interferon offer palliation, but only bone marrow transplantation provides for cure. Because the majority of CML patients are not candidates for allogeneic transplantation, autologous strategies have emerged as an alternative. Data from murine models of CML provide insights into the mechanisms by which autotransplant might be effective in the treatment of CML. Further dissection of the molecular pathways by which the BCR/ABL protein can induce leukemia offers the promise of a more targeted, rationally-designed therapy. When used for remission maintenance therapy following autologous bone marrow transplantation, specific inhibitors of BCR/ABL should provide for long term disease-free survival.
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PMID:Rationalizing autotransplant strategies for chronic myeloid leukemia. 917 99

New treatments which may change the course of a disease, or which have potential carcinogenicity, may result in the development of new cytogenetic or clinical disorders. Three patients with Philadelphia chromosome-positive (Ph-positive) chronic myeloid leukemia (CML) who developed new cytogenetic abnormalities after achieving a cytogenetic complete remission (CR) of their Ph-positive disease with interferon alpha (IFN-alpha) based therapy are described. Patient 1 developed chromosomal abnormalities involving chromosomes 5 (5q13-34) and later 7 (monosomy 7) 60 months after the start of therapy and 20 months after IFN-alpha was discontinued. A myelodysplastic syndrome was noted 83 months from the start of therapy. Patient 2 developed a myeloproliferative syndrome with 18p11 chromosomal abnormalities 90 months after the start of the therapy and 60 months after IFN-alpha was discontinued. Patient 3 developed a chromosome 11 abnormality (11q21-23) 23 months after the start of therapy, without hematological manifestations. All three patients remain in cytogenetic CR of Ph-positive disease with the hypermetaphase fluorescent in situ hybridization and polymerase chain reaction studies for BCR/ABL showing minimal residual disease. The emergence of new cytogenetic or clinical disorders in patients with CML on IFN-alpha therapy needs to be monitored. These findings may be related to changing the natural course of CML, to therapy, or to the emergence of suppressed clones in a stem cell disorder.
Leukemia 1997 May
PMID:Emergence of new clonal abnormalities following interferon-alpha induced complete cytogenetic response in patients with chronic myeloid leukemia: report of three cases. 918 Mar 6

BCR-ABL is a chimeric oncoprotein that exhibits deregulated tyrosine kinase activity and is implicated in the pathogenesis of Philadelphia chromosome (ph1)-positive leukemia. We have previously shown SH2-containing phosphotyrosine phosphatase SHP-2 forms stable complexes with BCR-ABL and Grb2 in BCR-ABL transformed cells (T., Tauchi, et al. J. Biol. Chem. 269, 15381, 1994). To elucidate the structural requirement of BCR-ABL for the interactions with SH2-containing signaling molecules, we examined a series of BCR-ABL mutants which include the Grb2 binding site deleted BCR-ABL (1-63 BCR/ABL), the tetramerization domain deleted BCR-ABL (64-509 BCR/ABL), and the SH2 domain deleted BCR-ABL (BCR/ABL delta SH2). These BCR-ABL mutants were previously shown to reduce the transforming activity in fibroblasts. We found that the tetramerization domain deleted BCR-ABL did not induce the tyrosine phosphorylation of SHP-2 and the interactions of BCR-ABL, SHP-2, and Grb2. In vitro kinase assays have also shown the tetramerization domain deleted BCR-ABL mutant did not phosphorylate GST-SHP-2 in vitro. SHP-2 was co-immunoprecipitated with P13Kinase in BCR/ABL p210 transformed cells, however this interaction was not observed in the tetramerization domain deleted BCR-ABL mutant. Therefore the tetramerization domain of BCR-ABL is essential for interactions of these downstream molecules.
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PMID:A coiled-coil tetramerization domain of BCR-ABL is essential for the interactions of SH2-containing signal transduction molecules. 918 66

Chronic myelogenous leukemia presents two distinct clinical phases: the chronic phase is characterised by a marked expansion of the myeloid compartment which still retains a normal differentiative capacity, whereas a differentiation block is the clinical hallmark of the acute transformation. The molecular mechanism underlying the CML progression are still poorly understood. The occurrence of additional molecular lesions, involving the p53, the RAS and the p16 genes may complement and fulfil the BCR/ABL transforming potential, finally leading to an acute leukemic phenotype. However, several lines of evidence suggest that also quantitative changes of the BCR/ABL transcript amounts could explain the progression of the leukemic phenotype in the BCR/ABL-positive hematologic malignancies.
Leukemia 1997 Apr
PMID:Molecular events in chronic myeloid leukemia progression. 920 43

A novel human myeloid leukaemia cell line (HNT-34) was established from the peripheral blood of a 45-year-old female patient with acute myelogenous leukaemia (AML) transformed from chronic myelomonocytic leukaemia (CMMoL) with 3q21q26 syndrome. Morphologically, the HNT-34 cells were undifferentiated blasts which were negative for myeloperoxidase. The HNT-34 cells were positive for CD4, CD13, CD33 and CD34, but negative for CD41a and CD42b. The cells actively proliferated in suspension with a doubling time of 26-27h in the absence of any growth factors. Neither proliferative advantage nor differentiation was observed with the addition of G-CSE GM-CSF, IL-3, TPO, DMSO or PMA. Cytogenetic analysis showed 46,XX. t(3;3)(q21;q26), t(9;22)(q34;q11),20q-. Molecular analysis showed expression of EVI1 gene, P210 and P190 BCR/ABL chimaeric transcripts. The chromosomal breakpoint at 3q26 of HNT-34 cell line was located to approximately 200 kb 5' of FIM3 locus and more upstream of the MDS1. which is the same region as that of somatic cell hybrid line H10C. The breakpoint at 3q21 was located within the 390 kb centromeric from the breakpoint cluster region. These results suggest that the HNT-34 cell line may be a useful tool for the elucidation of the mechanisms of leukaemogenesis which involve the 3q21q26 syndrome and Ph1 chromosome.
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PMID:Establishment of a novel human myeloid leukaemia cell line (HNT-34) with t(3;3)(q21;q26), t(9;22)(q34;q11) and the expression of EVI1 gene, P210 and P190 BCR/ABL chimaeric transcripts from a patient with AML after MDS with 3q21q26 syndrome. 926 39


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