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)

The translocation t(3;21)(q26;q22) is a rare recurring clonal abnormality, either preceding or associated with blast crisis in Philadelphia chromosome-positive chronic myeloid leukemia (CML) patients. We previously localized the chromosomal breakpoints at 3q26.2 and 21q22.2, using high resolution chromosomal analysis. Two genes of interest are localized near the breakpoints, the transferrin receptor gene and the ETS2 proto-oncogene. Their chromosomal localizations, determined by in situ hybridization on normal metaphase cells, were 3q29 and 21q22.3, respectively. They underwent a reciprocal translocation in patients with t(3;21). Their structures were not altered by the translocation, and both were expressed to varying levels in t(3;21) patients. Southern blotting investigations showed that the structure of other single-copy genes, including FIM3, localized near the breakpoints, were not affected by the translocation. An analysis of ETS2 expression performed on CML patients without t(3;21) showed the presence of the transcript in 100% of the blast crises, but only in 20% of the chronic-phase patients. Thus ETS2 expression may either be linked to or play a role in CML progression.
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PMID:Expression of the ETS2 and transferrin receptor genes in Philadelphia-positive chronic myeloid leukemia patients with a reciprocal t(3;21). 138 56

The actual significance of the type of BCR-ABL rearrangement in chronic myeloid leukemia (CML) prognosis remains controversial. Also, the molecular events that lead to CML progression are largely unknown. We analyzed the M-BCR breakpoint position in 64 CML patients by Southern blot and correlated the molecular findings with the cytogenetic, hematologic, and clinical data. No statistically significant differences were found with respect to the clinical and hematologic data presented at diagnosis or in the median duration of chronic phase (CP) and survival between the groups of patients with 5' and 3' breakpoints. We also studied by PCR-SSCP and direct sequencing the p53 gene in patients with specimens available in both chronic phase and blast crisis. We identified p53 mutations in 17% of the blast crisis samples analyzed, whereas no abnormalities were found in CP. This finding suggests that only in a minor fraction of cases are lesions in the p53 gene involved in transformation. Given the present findings, along with previous reports, we believe that a novel mechanism to explain the heterogeneity of CML should be postulated and actively pursued, as should the identification of secondary molecular events more consistently involved in progression.
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PMID:Further evidence for the lack of correlation between the breakpoint site within M-BCR and CML prognosis and for the occasional involvement of p53 in transformation. 853 22

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.
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PMID:Molecular events in chronic myeloid leukemia progression. 920 43

The occurrence of acute transformation during the treatment of chronic myeloid leukemia (CML) is still a poorly understood mechanism. In this disease p53, p16INK4A, p15INK4B, p57KIP2 mutations and p15INK4B/p16INK4A homo/hemizygous deletions were analyzed in the initial diagnosis phase and during the treatment phase of twelve CML cases, in order to establish whether there was a consistent molecular genetic alteration in its progression. During the treatment period, four of twelve cases had blastic crisis. All the mutations observed in p53, p16INK4A and p15INK4B cumulated in three out of four CML cases who had blastic crises. In one case, p53 codon 282 mutation (CGG-->TGG; arg-->trp) were observed in initial diagnosis. Seven months later, G-->C transition in the 3' side of p15 cDNA (778. nucleotide) was observed in the accelerated phase with the same p53 codon 282 mutation. Thirteen months later, this patient died as a result of blastic crisis. The patient in blastic crises in the initial diagnosis phase had a mis-sense point mutation in p16 codon 69 (ACT-->AGT; thr-->ser) and a polymorphism in codon 68 (GCC-->GCG). Six months later, this patient also died. In one case, p53 codon 237 mutation (ATG-->ATA; met-->ile) were observed in the initial diagnosis phase. Then months later, the patient died as a result of blastic crises. No p15INK4B/p16INK4A homo/hemizygous deletion and p57KIP2 gene mutation which was described in the same pathway were observed in CML progression. These results indicate that p15INK4B and p16INK4A gene alterations may have an affect on the progression of CML-like p53 mutation. A correlation was found with the progression of CML and p53, p15INK4B and p16INK4A somatic mutations. Finding p15INK4B and p16INK4A gene alteration as well as p53 mutations may be a prognostic marker in patients with CML.
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PMID:P53, p15INK4B, p16INK4A and p57KIP2 mutations during the progression of chronic myeloid leukemia. 1006 44

Loss or reduced expression of the fragile histidine triad (FHIT) gene, a tumor suppressor gene localized at chromosome 3p14.2, is common in several solid and hematological cancers and has been associated with tumor progression and worse prognosis. The role of the FHIT gene in the pathogenesis of chronic myelogenous leukemia (CML) or its progression from a chronic phase to the accelerated and blastic phases is not known. The aim of this study was to evaluate whether Fhit protein expression is altered in CML, and whether it plays any role in CML progression, disease responsiveness to therapy, or prognosis. A total of 195 patients with Philadelphia chromosome-positive CML were evaluated, including 129 patients in early chronic phase (time from diagnosis to study, 12 months or less), 30 patients in late chronic phase, and 36 patients in the accelerated and blastic phases. The levels of cellular Fhit protein expression were determined using Western blot analysis and solid-phase RIA and compared to the levels in 31 normal marrows. The median Fhit expression in normal marrows was assigned a value of 1, and the levels in CML samples were normalized to the median of the normal control. Fhit levels in CML samples were evaluated in relation to CML phase and patient characteristics and prognosis in the early chronic phase. The median Fhit value in CML samples was 0.89 (range, 0.34-2.62). Eight of the 195 (4%) CML samples showed Fhit levels <0.5 and lacked detectable Fhit protein by Western blot. There was no difference in the levels of Fhit expression by different CML phases. In early chronic phase, reduced Fhit expression tended to be associated with leukocytosis (P = 0.04) and lower platelet counts (P = 0.01), but not with poorer-risk groups. No differences in response to IFN-alpha therapy or in survival were observed by different Fhit levels. Lack of Fhit protein expression was detected in 4% of CML cases, and reduced expression occurred in a subpopulation of patients. However, reduced Fhit expression is not associated with progression, response to therapy, or prognosis in CML.
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PMID:Significance of FHIT expression in chronic myelogenous leukemia. 1063 40

We used a sensitive, quantitative bisulfite PCR assay, methylation sensitive single nucleotide primer extension (Ms-SNuPE), to measure methylation of the 5' CpG islands of c-abl and p15 in chronic myelogenous leukemia (CML) patients during progression. We found that the Pa promoter of c-abl was methylated in 81% (17/21) of the white blood cells (WBCs) of CML patients, which correlates with previous reports. In contrast, WBCs from healthy donors, acute myelogenous leukemias, acute lymphocytic leukemias, and myelodysplastic syndromes were unmethylated at the c-abl Pa promoter locus. We also observed p15 hypermethylation in 24% (8/34) of CML cases. Methylation of the p15 but not c-abl Pa promoters was associated with CML progression (P = 0.047 vs 0.46), and the two events were independently acquired. We conclude that de novo methylation of c-abl and p15 both occur in CML, and analysis of DNA methylation changes using the bisulfite-based MS-SNuPE assay allows both a sensitive and quantitative assessment of these molecular events compared to other methods currently utilized. (Blood. 2000;95:2990-2992)
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PMID:Quantitative measure of c-abl and p15 methylation in chronic myelogenous leukemia: biological implications. 1077 50

The murine bone marrow retroviral transduction and transplantation model of chronic myelogenous leukemia (CML) imperfectly mimics human CML because the murine CML-like disease causes death of all animals from an overwhelming granulocytosis within 3 to 4 weeks. In this report, mice reconstituted with P210(BCR/ABL)-transduced bone marrow cells received posttransplantation therapy with either the tyrosine kinase inhibitor STI571 or placebo. Compared with the rapidly fatal leukemia of placebo-treated animals, 80% of the STI571-treated mice were alive on day 74, with marked improvement in peripheral white blood counts and splenomegaly. There was decreased tyrosine phosphorylation of STAT5, Shc, and Crk-L in leukemic cells from STI571-treated animals, consistent with STI571-mediated inhibition of the Bcr/Abl tyrosine kinase in vivo. In some STI571-treated animals Bcr/Abl messenger RNA and protein expression were markedly increased. In contrast to the polyclonal leukemia of placebo-treated mice, STI571-treated murine CML was generally oligoclonal, suggesting that STI571 eliminated or severely suppressed certain leukemic clones. None of the STI571-treated mice were cured of the CML-like myeloproliferative disorder, however, and STI571-treated murine CML was transplanted to secondary recipients with high efficiency. These results demonstrate the utility of this murine model of CML in the evaluation of novel therapeutic agents against Bcr/Abl-induced leukemias. This improved murine chronic-phase CML model may be a useful tool for the study of STI571 resistance, CML progression, and the anti-CML immune response.
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PMID:Establishment of a murine model for therapy-treated chronic myelogenous leukemia using the tyrosine kinase inhibitor STI571. 1167 55

Natural killer (NK) cells decrease in function during chronic myelogenous leukemia (CML) progression from chronic phase to blast crisis, and they can become BCR/ABL(+) late in the disease course. To study this altered function, NK92 cells were transduced with the BCR/ABL oncogene. In contrast to the parental cells, which died when deprived of interleukin 2 (IL-2), p210(+) NK92 cells proliferated and survived indefinitely in the absence of IL-2. BCR/ABL also decreased the natural cytotoxicity of NK92 cells against K562 targets, without affecting IL-2, interferon gamma (IFN-gamma), or tumor necrosis factor alpha (TNF-alpha) production. Although the ABL-specific tyrosine kinase inhibitor imatinib mesylate (STI-571) had no effect on parental NK92 cells, it markedly decreased the growth and survival of IL-2-independent p210(+) NK92 cells. In contrast to the parental cell line, serial analysis of p210(+) NK92 cells detected small populations that clonally expressed one or more killer immunoglobulin-like receptors (KIRs). Unlike the decreased natural cytotoxicity, the function of the activating CD158j receptor remained intact. Southern blotting and hybridization with an enhanced green fluorescence protein (eGFP) probe showed that KIR(-) and KIR(+) NK92 cells were all derived from the same clone, suggesting that KIR acquisition remains dynamic at the maturational stage represented by the NK92 cell line. When tested in primary CD56(+bright) NK cells, p210 induced partial IL-2-independent growth and increased KIR expression similar to findings in NK92 cells. This is the first study to show that BCR/ABL, well known for its effects on the myeloid lineage, can alter the function of lymphoid cells, which may be associated with the defect in innate immunity associated with CML progression.
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PMID:BCR/ABL alters the function of NK cells and the acquisition of killer immunoglobulin-like receptors (KIRs). 1251 22

The expression of the suppressor of cytokine signalling-1 (SOCS1) protein is induced in response to stimulation by several cytokines. The induced SOCS1 inhibits the signalling pathway through the association with a variety of tyrosine kinase proteins. In this study, the mutation analyses, CpG island methylation status, and the expression of the SOCS1 gene in 112 chronic myeloid leukaemia (CML) samples, five leukaemia cell lines, and 30 normal controls were analysed. No genetic mutations of SOCS1 gene were noted in the CML samples. The SOCS1 gene was hypermethylated in 67% and 46% of the blastic and chronic phase CML samples respectively (P < 0.0001). However, there was no methylation of the SOCS1 gene in normal controls or CML in molecular remission. The methylation status of the SOCS1 gene is consistent with the results of the real-time quantitative reverse transcription polymerase chain reaction and immunocytochemistry staining. Our results demonstrate that the SOCS1 gene silencing is caused by the methylation of CpG islands in CML and is reversed to an unmethylated status in molecular remission. As SOCS1 has universal activity to negatively regulate several cytokine signalling pathways, the loss of the negative regulation of cytokine signalling by the SOCS1 may play a role in the pathogenesis of CML progression.
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PMID:Epigenetic alteration of the SOCS1 gene in chronic myeloid leukaemia. 1461 69

In the present work we study the HOXA9 expression in sequential samples of patients with CML using RT-PCR. To obtain a semi-quantitative value, the HOXA9 expression was referred to the ABL gene in the same sample. The relative HOXA9 expression was higher in patients in the accelerated phase of the disease (p<0.005). Interestingly, a patient with poorer prognosis (high Sokal's score), showing the highest HOXA9/ABL ratio, quickly entered a blast crisis and died 5 months later. These first results could be considered as an evidence of an actual biological phenomenon that could provide additional information about the HOXA9 role in the CML progression.
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PMID:HOXA9 gene expression in the chronic myeloid leukemia progression. 1663 Jun 59


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