Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0023473 (chronic myeloid leukemia)
 18,916 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

This study was aimed to quantitatively detect the expression level of beta-catenin and bcr/abl in different phases of chronic myeloid leukemia (CML) and to analyze their potential relationship and significance in the progression of CML. First, the total RNA isolated from BMMNC of patients with CML and donors was reversely transcribed into cDNA. The real-time quantitative PCR method was used to analyze the expression level of beta-catenin and bcr/abl. The expression level of beta-catenin and bcr/abl in different phases of CML was compared and the correlation was analyzed between the two genes. The results showed that the beta-catenin gene in BMMNC of blast crisis of CML patients was expressed significantly higher than that in chronic phase (p < 0.001) and accelerated phase (p = 0.016) of CML patients and in normal donors (p = 0.004). The expression of bcr/abl in blast crisis of CML was statistically higher than that in chronic phase of CML (p = 0.001). The expression levels of beta-catenin and bcr/abl were correlated with each other in CML patients (r = 0.620, p < 0.001). It is concluded that the beta-catenin gene in blast crisis of CML patients express higher than that in chronic phase and accelerated phase of CML, and its expression level is correlated with the level of bcr/abl expression. The increased expression of beta-catenin may be account partly for the blast crisis of CML.
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PMID:[Expression of beta-Catenin Gene in CML and its relationship with bcr/abl]. 1795 64

A key characteristic of stem cells and cancer cells is their ability to self-renew. To test if Wnt signaling can regulate the self-renewal of both stem cells and cancer cells in the hematopoietic system, we developed mice that lack beta-catenin in their hematopoietic cells. Here we show that beta-catenin-deficient mice can form HSCs, but that these cells are deficient in long-term growth and maintenance. Moreover, beta-catenin deletion causes a profound reduction in the ability of mice to develop BCR-ABL-induced chronic myelogenous leukemia (CML), while allowing progression of acute lymphocytic leukemia (ALL). These studies demonstrate that Wnt signaling is required for the self-renewal of normal and neoplastic stem cells in the hematopoietic system.
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PMID:Loss of beta-catenin impairs the renewal of normal and CML stem cells in vivo. 1806 30

Tumor propagation by cancer stem cells (CSCs) requires their ability to self-renew, and yet the signal pathways involved in this process remain poorly defined. In the December issue of Cancer Cell, Zhao et al. (2007) provide compelling evidence that Wnt/beta-catenin signaling is crucial for the maintenance of chronic myelogenous leukemia (CML) stem cells.
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PMID:Knocking the Wnt out of the sails of leukemia stem cell development. 1837 98

The goal of the current study is to evaluate the role of beta-catenin in chronic myeloproliferative disorders. Expression of beta-catenin was analyzed by immunohistochemistry in formalin-fixed decalcified bone marrow biopsy specimens from 52 chronic myeloproliferative disorder cases and 6 nonchronic myeloproliferative disorder bone marrows as controls. The frequency of moderate to strong beta-catenin staining of megakaryocytes was significantly higher in polycythemia vera cases and in essential thrombocythemia cases than in chronic myelogenous leukemia cases (polycythemia vera versus chronic myelogenous leukemia, P = .002345, Fisher exact; and essential thrombocythemia versus chronic myelogenous leukemia, P = .002288), chronic idiopathic myelofibrosis cases (polycythemia vera versus chronic idiopathic myelofibrosis, P = .006707 and essential thrombocythemia versus chronic idiopathic myelofibrosis, P = .006932) or control cases (polycythemia vera versus control, P = .010489 and essential thrombocythemia versus control, P = .0113120). The erythroid and myeloid lineages showed absent to weak beta-catenin staining in most cases. In conclusion, these results indicate that the Wnt/beta-catenin signaling pathway may have a role in megakaryocytopoiesis in polycythemia vera and essential thrombocythemia. In addition, beta-catenin may be a useful marker for differentiating polycythemia vera and essential thrombocythemia from other types of chronic myeloproliferative disorders.
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PMID:The role of beta-catenin in chronic myeloproliferative disorders. 1861 46

In order to investigate the effect of shRNA targeted to beta-catenin on the growth of K562 cells, plasmid containing beta-catenin specific shRNA sequence was transfected into K562 cells by lipofectamine 2000, and G418 was added to screen the positive cells. Real-time PCR and Western blot were used to detect the expression of beta-catenin. Cell growth curve, MTT and colony forming cell assays were used to evaluate the proliferation potential of cells. The results showed that the mRNA level of beta-catenin was reduced significantly in K562 cells transfected into interfering plasmid as compared with control plasmid, while the protein level failed to demonstrate difference by the time of 72 hours after transfection. After long-term culture with G418, the count of positive cells enhanced in control group while no positive cells survived in the interfering group. Colony-forming cell assays revealed that the K562 cells in interfering group formed colonies with very small size and low forming rate, compared with the control group, though the growth curve and MTT failed to illustrate differences. It is concluded that the beta-catenin-specific shRNA mediated by plasmid can effectively knockdown the expression of beta-catenin gene and inhibit the colony-forming ability in K562 cells, it is a potential target for the therapy of CML, even in blast crisis.
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PMID:[Effect of shRNA targeted to beta-catenin on K562 cell growth]. 1871 47

Philadelphia chromosome-positive (Ph(+)) chronic myeloid leukemia (CML) induced by the BCR-ABL oncogene is believed to be developed from leukemic stem cells (LSCs), and we have previously shown in mice that LSCs for CML express the same cell surface markers that are also expressed on normal hematopoietic stem cells (HSCs). Although the inhibition of BCR-ABL kinase activity by imatinib is highly effective in treating human Ph(+) CML in chronic phase, it is difficult to achieve molecular remission of the disease, suggesting that LSCs remain in patients. In this study, we find that following imatinib treatment, LSCs not only remained but also accumulated increasingly in bone marrow of CML mice. This insensitivity of LSCs to imatinib was not because of the lack of BCR-ABL kinase inhibition by imatinib, and proliferating leukemic cells derived from LSCs were still sensitive to growth inhibition by imatinib. These results identify an LSC survival pathway that is not inhibited by imatinib. Furthermore, we show that beta-catenin in the Wnt signaling pathway is essential for survival and self-renewal of LSCs, providing a new strategy for targeting these cells.
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PMID:beta-Catenin is essential for survival of leukemic stem cells insensitive to kinase inhibition in mice with BCR-ABL-induced chronic myeloid leukemia. 1881 3

During blast crisis of chronic myelogenous leukemia (CML), abnormal granulocyte macrophage progenitors (GMP) with nuclear beta-catenin acquire self-renewal potential and may function as leukemic stem cells (Jamieson et al. N Engl J Med, 2004). To develop a mouse model for CML-initiating GMP, we expressed p210(BCR-ABL) in an established line of E2A-knockout mouse BM cells that retain pluripotency in ex vivo culture. Expression of BCR-ABL in these cells reproducibly stimulated myeloid expansion in culture and generated leukemia-initiating cells specifically in the GMP compartment. The leukemogenic GMP displayed higher levels of beta-catenin activity than either the nontransformed GMP or the transformed nonGMP, both in culture and in transplanted mouse BM. Although E2A-deficiency may have contributed to the formation of leukemogenic GMP, restoration of E2A-function did not reverse BCR-ABL-induced transformation. These results provide further evidence that BCR-ABL-transformed GMP with abnormal beta-catenin activity can function as leukemic stem cells.
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PMID:BCR-ABL-transformed GMP as myeloid leukemic stem cells. 1900 99

Wnt/beta-catenin is the most important and more understanding pathway in Wnt pathways, which is closely related to pathogenesis and development of many solid tumors. Recently, researches discovered that Wnt/beta-catenin signal pathway may be involved in malignant hematopoiesis, and abnormally activated in many hematological-malignancies. This article reviews the newest studies on relationship between Wnt/beta-catenin signal pathway and hematological malignancies (multiple myeloma, chronic myeloid leukemia, chronic lymphocytic leukemia, acute leukemia and so on) in order to reveal the related pathogenesis of hematological malignancies and provide new opinions for target therapy of these diseases.
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PMID:[Wnt/beta-catenin signal pathway and malignant hematological disease -- review]. 1923 87

Recent evidence suggests that a rare population of self-renewing cancer stem cells (CSC) is responsible for cancer progression and therapeutic resistance. Chronic myeloid leukemia (CML) represents an important paradigm for understanding the genetic and epigenetic events involved in CSC production. CML progresses from a chronic phase (CP) in hematopoietic stem cells (HSC) that harbor the BCR-ABL translocation, to blast crisis (BC), characterized by aberrant activation of beta-catenin within granulocyte-macrophage progenitors (GMP). A major barrier to predicting and inhibiting blast crisis transformation has been the identification of mechanisms driving beta-catenin activation. Here we show that BC CML myeloid progenitors, in particular GMP, serially transplant leukemia in immunocompromised mice and thus are enriched for leukemia stem cells (LSC). Notably, cDNA sequencing of Wnt/beta-catenin pathway regulatory genes, including adenomatous polyposis coli, GSK3beta, axin 1, beta-catenin, lymphoid enhancer factor-1, cyclin D1, and c-myc, revealed a novel in-frame splice deletion of the GSK3beta kinase domain in the GMP of BC samples that was not detectable by sequencing in blasts or normal progenitors. Moreover, BC CML progenitors with misspliced GSK3beta have enhanced beta-catenin expression as well as serial engraftment potential while reintroduction of full-length GSK3beta reduces both in vitro replating and leukemic engraftment. We propose that CP CML is initiated by BCR-ABL expression in an HSC clone but that progression to BC may include missplicing of GSK3beta in GMP LSC, enabling unphosphorylated beta-catenin to participate in LSC self-renewal. Missplicing of GSK3beta represents a unique mechanism for the emergence of BC CML LSC and might provide a novel diagnostic and therapeutic target.
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PMID:Glycogen synthase kinase 3beta missplicing contributes to leukemia stem cell generation. 1923 56

Bcr-Abl causes chronic myelogenous leukemia, a myeloproliferative disorder characterized by clonal expansion of hematopoietic progenitor cells. In this study, inducible expression of Bcr-Abl in TonB.210 cells is associated with increased production of intracellular reactive oxygen species (ROS), which is thought to play a role in survival signaling when generated at specific levels. Elevated ROS in Bcr-Abl-expressing cells were found to activate PI3k/Akt pathway members such as Akt and GSK3beta as well as downstream targets beta-catenin and Mcl-1. The activation of these proteins was inhibited by the flavoprotein inhibitor diphenyleneiodonium, which is commonly used to inhibit NADPH oxidase (Nox). This indicated that increased ROS might be related to increased activity of one member of the Nox family. Knock-down experiments using siRNA suggest that Nox-4 is the main source of increased ROS following Bcr-Abl expression. We showed that Bcr-Abl-induced ROS could also increase survival pathway signaling through redox inhibition of PP1alpha, a serine threonine phosphatase that negatively regulates the PI3k/Akt pathway. Overall our results demonstrate that Bcr-Abl expression increases Nox-4-generated ROS, which in turn increases survival signaling through PI3k/Akt pathway by inhibition of PP1alpha, thus contributing to the high level of resistance to apoptosis seen in these Bcr-Abl-expressing cells.
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PMID:Bcr-Abl-mediated redox regulation of the PI3K/AKT pathway. 1929 48


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