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Query: UMLS:C0023473 (chronic myeloid leukemia)
 18,916 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Chronic myelogenous leukaemia is a clonal neoplasm of the pluripotent haematopoietic stem cell which is characterized in most patients by a consistent cytogenetic abnormality known as the Philadelphia chromosome. This chromosome occurs as a consequence of a reciprocal translocation between the long arms of chromosomes 9 and 22 which results in the creation of a new gene comprising sequences from the c-abl gene on chromosome 9 and the bcr gene on chromosome 22. The protein encoded by this structurally altered hybrid gene differs from the normal c-abl gene product in both molecular weight and in tyrosine kinase activity. It is likely that these alterations in the c-abl gene product play a central role in the pathogenesis of this leukaemia.
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PMID:Molecular pathogenesis of chronic myelogenous leukaemia. 130 82

Herbimycin A, a selective inhibitor of tyrosine kinase activity, induced differentiation of leukemia cells isolated from Philadelphia chromosome-positive chronic myelogenous leukemia patients. However, it did not induce differentiation of leukemia cells from acute myelogenous leukemia patients, although these cells could be induced to differentiate by treatment with appropriate compounds. A selective inhibitor of tyrosine kinase might be useful in chemotherapy of Philadelphia chromosome-positive leukemia.
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PMID:Control of growth and differentiation of Philadelphia chromosome-positive leukemia cells by tyrosine kinase inhibitors. 130 24

Overwhelming evidence indicates a role for the deregulated ABL protein tyrosine kinase in the aetiology of CML and Ph-positive acute leukaemia. These disorders are characterized by the generation of BCR/ABL fusion proteins with elevated tyrosine kinase activity. Although much is known concerning the transforming potential of ABL proteins in various systems, very little is understood of the normal function and mode of regulation of ABL activity. The mechanism of oncogenic activation is therefore also obscure. In spite of this, our understanding of the molecular details of these chromosomal translocations allows the design of therapies directed against their unique, leukaemia-specific proteins and RNA products.
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PMID:Philadelphia chromosome-positive leukaemia: the translocated genes and their gene products. 130 69

Current evidence suggests that the expression of the tyrosine kinase p210bcr/abl in chronic myelogenous leukemia (CML) may directly induce the initial phase of granulocytic hyperplasia. However, the dysregulation of additional genes appears to be required for transition to the acute leukemic phase, as inferred by the appearance of recurrent secondary cytogenetic abnormalities in the majority of patients. To determine whether the expression of p210bcr/abl alone is responsible for this genetic instability, we introduced and expressed the bcr/abl gene from a retroviral vector in a clone of the interleukin-3 (IL-3) dependent myeloblastic 32D C13(G) cell line. Clonal and polyclonal cells transformed to IL-3 independent growth were observed for a period extending up to 6 months for changes in the expression of p210bcr/abl, cell proliferation, inhibition by prostaglandin E1 (PGE1), forskolin, and cyclic adenosine monophosphate (cAMP) analogues, regulation of the cell cycle, and karyotype. Whereas the properties of control vector infected 32D C13(G)' cells remained stable over time, cells expressing p210bcr/abl were phenotypically unstable. In cells expressing p210bcr/abl, we observed selective modulation of p210bcr/abl mRNA and protein expression, evolution from partial to full abrogation of IL-3 dependence, reduced serum requirements, increased cell proliferation, decreased inhibition by PGE1 and cAMP analogues, and the appearance of new structural and numerical chromosomal abnormalities with successive cell passages. These results indicate that expression of p210bcr/abl can directly predispose 32D C13(G)' cells to genetic instability, promotes the emergence of clones with an increased proliferative advantage, and may represent an in vitro model suitable for the study of mechanisms underlying progression to the acute leukemic phase in CML.
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PMID:Clonal evolution in a myeloid cell line transformed to interleukin-3 independent growth by retroviral transduction and expression of p210bcr/abl. 132 83

The hallmark of chronic myelogenous leukemia is the translocation of the human c-abl protooncogene (ABL) from chromosome 9 to the specific breakpoint cluster region (bcr) of the BCR gene on chromosome 22. The t(9;22)(q34;q11) translocation results in the formation of a BCR-ABL fusion gene that encodes a 210-kDa chimeric protein with abnormal tyrosine kinase activity. The ABL and BCR genes are expressed by normal cells and thus the encoded proteins are presumably nonimmunogenic. However, the joining-region segment of the p210BCR-ABL chimeric protein is composed of unique sequences of ABL amino acids joined to BCR amino acids that are expressed only by malignant cells. The current study demonstrates that the joining region of BCR-ABL protein is immunogenic to murine T cells. Immunization of mice with synthetic peptides corresponding to the joining region elicited peptide-specific, CD4+, class II major histocompatibility complex-restricted T cells. The BCR-ABL peptide-specific T cells recognized only the combined sequence of BCR-ABL amino acids and not BCR or ABL amino acid sequences alone. Importantly, the BCR-ABL peptide-specific T cells could recognize and proliferate in response to p210BCR-ABL protein. The response of peptide-specific T cells to protein demonstrated that p210BCR-ABL can be processed by antigen-presenting cells so that the joining segment is bound to class II major histocompatibility complex molecules in a configuration similar to that of the immunizing peptide and in a concentration high enough to stimulate the antigen-specific T-cell receptor. Thus, BCR-ABL protein represents a potential tumor-specific antigen related to the transforming event and shared by many individuals with chronic myelogenous leukemia.
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PMID:T-cell immunity to the joining region of p210BCR-ABL protein. 134 32

The BCR/ABL oncogene in chronic myelogenous leukemia produces an activated tyrosine kinase fusion protein (p210). Like other tyrosine kinase oncogenes, BCR/ABL can abrogate the interleukin-3 (IL-3) dependence of lymphoid cell lines. To investigate the ability of BCR/ABL to generate growth factor independence in myeloid cells, the IL-3 dependent myeloid cell line NFS/N1.H7 (H7) was transfected with the p210BCR/ABL-containing plasmid, pGD210. Stable clones A54 and A74 were capable of IL-3 independent growth and tumor formation in syngeneic mice. Relief of growth factor dependence was not mediated by autocrine release of IL-3. The baseline proliferation rate of the BCR/ABL transformed cells was greater than that of the parental H7 cells maximally stimulated by IL-3. Abundant constitutive expression of c-myc, c-jun, and c-fos was observed in the p210BCR/ABL transfectants even in low serum conditions. In contrast, c-myc expression in H7 cells was dependent upon IL-3 stimulation, and neither c-jun nor c-fos was highly expressed following IL-3 stimulation in H7 cells. Thus, BCR/ABL transformation and relief of IL-3 dependence involve not only pathways that can substitute for IL-3 induced growth via tyrosine kinase mediated signals, but also pathways that recruit constitutive c-jun and c-fos expression.
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PMID:BCR/ABL confers growth factor independence upon a murine myeloid cell line. 137 13

The observation made over 30 years ago that the Philadelphia chromosome is present in nearly all patients with CML led to the identification of a novel fusion gene bcr-abl. In the past few years, the biochemical and biological properties of bcr-abl have been extensively explored. Bcr sequences appear to activate c-abl for transformation by binding to the SH2 domain of c-abl in an intramolecular interaction, presumably interfering with the adjacent SH3 regulatory domain. Upon introduction into bone marrow cells, bcr-abl can cause acute or chronic leukaemias in mice and can stimulate the growth of many cell types, including multipotent stem cells, in vitro. Although their growth is stimulated, these cells are not fully malignant blastic leukaemias. The molecular events that occur during the progression to blast crisis of CML remain largely undefined, but existing animal models and in vitro culture systems will be useful for identifying or testing candidate genes. The study of tyrosine kinase oncogenes in general will probably lead to the identification of relevant bcr-abl substrates. The elucidation of these molecules as well as more downstream events in the bcr-abl signalling pathway offers the hope for novel therapeutic interventions to control Philadelphia chromosome leukaemias.
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PMID:The bcr-abl gene in chronic myelogenous leukaemia. 145 Nov 13

Chronic myeloid leukaemia (CML) is a generic term that include five apparently distinct entities. The best known form, the classical Ph-positive subtype, accounts for about 90% of all cases of CML. The morphology of its presentation blood film is highly characteristic but is also seen in about half of the remaining 10% of cases, which are Ph-negative. This classical morphological subtype, whether Ph-positive or Ph-negative I describe as 'chronic granulocytic leukaemia' to refer to the exuberant granulocytic proliferation which is its hallmark. This term is often used indiscriminately and interchangeably with 'chronic myeloid leukaemia' and similar terms, just as 'chronic lymphocytic leukaemia' was, until recently, used to cover the chronic lymphoid leukaemias in general, but is now used in a specific sense. Chronic granulocytic leukaemia (CGL), whether Ph-positive or Ph-negative, is almost always BCR-rearranged and associated with the production of a unique 210-kd protein with enhanced tyrosine kinase activity. Most of the remaining cases of Ph-negative CML are examples of either chronic myelomonocytic leukaemia (CMML), a subtype almost as homogeneous as CGL, and characterized in its presentation blood film by the presence of monocytes and neutrophils but few immature granulocytes, or atypical CML (aCML), distinct from and less homogeneous than either CGL or CMML, in which some cases also share features with CGL while others share some with CMML. CMML and aCML do not show BCR rearrangement and are not associated with the production of p210kd. CGL, CMML, and aCML, though characterized on morphological features differ in their clinical features and behaviour, response to treatment and survival.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Haematological differences between chronic granulocytic leukaemia, atypical chronic myeloid leukaemia, and chronic myelomonocytic leukaemia. 149 35

Herbimycin A, a benzoquinoid ansamycin antibiotic, was demonstrated to decrease intracellular phosphorylation by protein tyrosine kinase (PTK). In Philadelphia chromosome (Ph1)-positive leukemias such as chronic myelogenous leukemia (CML) and Ph1-positive acute lymphoblastic leukemia (ALL), both of which express bcr-abl fused gene products (P210bcr-abl or P190bcr-abl protein kinase) with augmented tyrosine kinase activities, herbimycin A markedly inhibited the in vitro growth of the Ph1-positive ALL cells and the leukemic cells derived from CML blast crisis. However, the same dose of herbimycin A did not inhibit in vitro growth of a broad spectrum of Ph1-negative human leukemia cells, and several other protein kinase antagonists also displayed no preferential inhibition. Furthermore, we demonstrated that herbimycin A has an antagonizing effect on the growth of transformed cells by a transfection of retroviral amphotrophic vector expressing P210bcr/abl into a murine interleukin (IL)-3-dependent myeloid FDC-P2 cell line. This inhibition was abrogated by the addition of sulfhydryl compounds, similar to the reaction previously described for Rous sarcoma virus transformation. The inhibitory effect of herbimycin A on the growth of Ph1-positive cells was associated with decreased bcr/abl tyrosine kinase activity, but no decrease of bcr-abl mRNA and protein, suggesting that the inactivation of bcr-abl tyrosine kinase activity by herbimycin A may be induced by its binding to the bcr-abl protein portion that is rich with sulfhydryl groups. The present study indicates that herbimycin A is a beneficial agent for the investigation of the role of the bcr-abl gene in Ph1-positive leukemias and further suggests that the development of agents inhibiting the bcr-abl gene product may offer a new therapeutic potential for Ph1-positive leukemias.
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PMID:Effect of herbimycin A, an antagonist of tyrosine kinase, on bcr/abl oncoprotein-associated cell proliferations: abrogative effect on the transformation of murine hematopoietic cells by transfection of a retroviral vector expressing oncoprotein P210bcr/abl and preferential inhibition on Ph1-positive leukemia cell growth. 151 46

Herbimycin A, a specific tyrosine kinase inhibitor, induced erythroid differentiation of human myelogenous leukemia K562 cells with a high level of bcr/abl tyrosine kinase. Several derivatives of herbimycin A were synthesized and their effects on cell proliferation and differentiation of K562 cells were examined. Of the compounds tested, 19-allylaminoherbimycin A was the most effective in inducing differentiation of K562 cells. However, the parent compound was the most potent growth inhibitor, suggesting that chemical modification of herbimycin A reduces the growth-inhibiting activity. The sensitivities of K562 cells to herbimycin derivatives were different from those of a rat kidney cell line infected with Rous sarcoma virus (v-src), suggesting that bcr/abl kinase may differ in sensitivity from other tyrosine kinases. These results indicate that a specific inhibitor of bcr/abl kinase could be an effective antitumor agent against chronic myelogenous leukemia.
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PMID:Effects of herbimycin A derivatives on growth and differentiation of K562 human leukemic cells. 156 67


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