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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 characteristic genetic exchange in chronic myeloid leukemia (CML) is the fusion of the ABL proto-oncogene and a specific part of the BCR or phl gene. Detection of this exchange by cytogenetic or Southern blot analysis is highly diagnostic for CML. The latter approach has not previously been used to quantify the relative proportions of leukemic and non-leukemic cells. We have assessed the feasibility of estimating the relative proportion of leukemic cells present in a sample by densitometric analysis of autoradiographs of Southern blots. In dilution experiments of CML cells with normal cells, a linear relationship could be demonstrated between the relative intensity of the autoradiograph band corresponding bcr rearrangement and the proportion of leukemic cells present. This relationship was found to be largely independent of autoradiograph exposure time. Six patients receiving various therapies have been evaluated for as long as 4.5 years by repeated densitometric and cytogenetic analysis. In general, a declining proportion of Philadelphia (Ph) chromosome positive cells was paralleled by decreasing intensity of the autoradiograph band representing bcr rearrangement. Densitometric changes were often seen prior to the detection of Ph negative cells. This analysis appears to provide a sensitive method for monitoring patients with CML.
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PMID:Densitometric analysis of Southern blot autoradiographs and its application to monitoring patients with chronic myeloid leukemia. 207 39

Chronic myeloid leukaemia (CML) is an excellent model for the study of molecular rearrangements caused by a cytogenetic anomaly associated with a disease. The formation of a Philadelphia chromosome by translocation between chromosomes 9 and 22 provokes the breaking and migration of a cellular oncogen (ABL), located in the 9q34 region, towards chromosome 22 and the 22q11 region where the PHL gene is situated. This gene is broken in the bcr area the rearrangements of which are specific to CML. The ABL and PHL genes fragments fuse together, creating a new hybrid gene which is transcribed into an 8.5 kilobase messenger RNA specific to CML. This RNA is translated into a 210 kilodalton protein whose abnormally high tyrosine kinase activity seems to contribute to the development of the disease. Genetic engineering techniques improve our understanding of CML molecular mechanisms and can be very useful to clinicians as they permit the diagnosis of CML in some cases devoid of chromosomal markers, and the detection of a possible relapse in marrow-grafted patients with a much greater sensitivity (one in 100,000 cells) than that of cytogenetics.
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PMID:[Chronic myeloid leukemia: from cytogenetics to molecular biology]. 209 36

Interferon alfa has been used in the treatment of myeloproliferative disorders, particularly chronic myeloid leukemia, polycythemia vera, and idiopathic thrombocythemia. The effectiveness of interferon alfa in agnogenic myeloid metaplasia needs additional evaluation, although preliminary evidence suggests that it may be more efficacious when used in the cellular (ie, proliferative) phase than when the marrow is fibrotic or osteosclerotic. Cytogenetic and molecular changes after interferon alfa therapy are apparent in patients with chronic myeloid leukemia, as manifested by change in the Philadelphia chromosome and BCR-ABL gene, respectively. The exact role of interferon in prolonging the life of chronic myeloid leukemia patients, however, remains to be determined in larger studies of longer duration. Interferon treatment seems to be well tolerated, and the frequency of treatment-limiting toxicity is low. Data to date suggest that interferon alfa may be a new and effective drug for the treatment of the myeloproliferative disorders.
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PMID:Interferon in the treatment of myeloproliferative diseases. 211 94

In the great majority of patients with chronic myelogenous leukemia (CML) the reciprocal translocation between chromosomes 9 and 22, t(9;22)(q34;q11), resulting in the Philadelphia (Ph) chromosome produces fusion DNA sequences consisting of the 5' part of the major breakpoint cluster region-1 (M-BCR-1) and the ABL protooncogene which encodes for the P210BCR-ABL phosphoprotein with tyrosine kinase activity implicated in the pathogenesis of CML. Molecular analysis was performed on 25 patients with Ph-positive CML using 2 breakpoint cluster region (bcr) probes within the M-BCR-1 DNA sequences, and two of them did not contain either detectable rearranged DNA homologous to the 5' side bcr probe or ABL-related fusion mRNA. The chromosomal in situ hybridization technique revealed that these two Ph-positive CML cases did not carry DNAs homologous to the 5' bcr or ABL probes on the Ph chromosome. Furthermore, one of the two Ph-positive CML cases did not show either rearranged DNA or regions homologous to the 3' bcr probe on a 9q+ chromosome, while the other CML case showed a rearrangement detected by the 3' bcr probe and transposition of the 3' bcr homologous to the 9q+ chromosome. Thus, the possibility is raised that the BCR/ABL fusion DNA has been deleted in rare CML cases, and that the deletion possibly occurred in a stepwise manner following the formation of the Ph chromosome at any stage of the disease.
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PMID:Philadelphia chromosome-positive chronic myelogenous leukemia with deleted fusion of BCR and ABL genes. 215 92

We studied the cells from three selected patients with Ph-chromosome-negative chronic myeloid leukemia (CML) by Southern blotting, polymerase chain reaction, and in situ hybridization of informative probes to metaphase chromosomes. All three patients had rearrangement of M-BCR sequences in the BCR gene and expression of one or other of the mRNA species characteristic of Ph-positive CML. Leukemic metaphases studied after trypsin-Giemsa banding were indistinguishable from normal. The ABL probe localized both to chromosome 9 and 22 in each case. A probe containing 3' M-BCR sequences localized only to chromosome 22, and not to chromosome 9 as would be expected in Ph-positive CML. Two new probes that recognize different polymorphic regions distal to the ABL gene on chromosome 9 in normal subjects localized exclusively to chromosome 9 in two patients and to both chromosomes 9 and 22 in one patient. These results show that Ph-negative CML with BCR rearrangement is associated with insertion of a variable quantity of chromosome 9 derived material into chromosome 22q11; there is no evidence for reciprocal translocation of material from chromosome 22 to chromosome 9.
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PMID:Interstitial insertion of varying amounts of ABL-containing genetic material into chromosome 22 in Ph-negative CML. 216 19

Leukemic cells from a patient with Ph-negative chronic myeloid leukemia (CML) had a normal karyotype. M-BCR was rearranged and chromosome in situ hybridization showed an ABL insertion between 5' and 3' M-BCR on an apparently normal chromosome 22. The association of 5' BCR and 3' ABL at the 5' junction of the chromosome 9 insert was typical of that found for the BCR-ABL fusion gene in other patients with the standard t(9;22) and CML. With an M-bcr-3' probe, we cloned and characterized a 3' junction fragment. Field inversion gel electrophoresis and chromosome in situ hybridization studies using a probe isolated from genomic DNA 5' of the junction showed that 3' M-BCR was joined to a region of chromosome 9q34 rich in repetitive sequences and lying some distance 3' of ABL. The chromosome 9 insert was at least 329 kilobases long and included 3' ABL and a larger portion of chromosome 9q34. Our results allowed us to exclude transposon- or retroviral-mediated insertion of ABL into chromosome 22. Instead, we favored a two-translocation model in which a second translocation reconstituted a standard t(9;22)(q34;q11) but left the chromosome 9 insert, including 3' ABL, in chromosome 22.
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PMID:Ph-negative chronic myeloid leukemia: molecular analysis of ABL insertion into M-BCR on chromosome 22. 217 2

Bone marrow cells from 37 patients with chronic myelogenous leukemia (CML), who had the characteristic Philadelphia chromosome in their leukemic cells, were examined for ABL gene rearrangement by pulsed-field gel electrophoresis. By using several probes from the ABL gene, we found that in 33 of 37 (89%) patients studied, the translocation breakpoints in ABL fell within the 175-kilobase (kb) intron between exons 1b and 1a. Furthermore, breakpoints in this intron clustered in three regions, approximately 30 +/- 5, 100 +/- 13, and 135 +/- 8 kb downstream from exon 1b. These findings suggest that there may be specific sequences in this intron that facilitate the processes of chromosomal translocation.
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PMID:Chromosomal breakpoints within the first intron of the ABL gene are nonrandom in patients with chronic myelogenous leukemia. 219 62

We studied two cases of chronic myelogenous leukemia (CML) with unusual variant Philadelphia (Ph) translocation (22;22)(q11;q13). Southern blot analysis showed a chromosomal break in the BCR gene within the 5.8-kilobase (kb) breakpoint cluster region (bcr), between bcr exons 2 and 3 and between bcr exons 3 and 4, respectively. Chimeric bcr-abl mRNA was detected using polymerase chain reaction (PCR) which amplified, according to the respective bcr breakpoints, bcr exon 2-abl exon II and bcr exon 3-abl exon II junction products. These results further support the involvement, even when not cytogenetically detectable, of the 9q34 chromosomal region in all variant Ph translocations and that BCR-ABL gene fusion products are causally involved in the development of Ph positive CML.
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PMID:Chronic myeloid leukemia with unusual variant Ph translocation (22;22)(q11;q13). Two cases with chimeric BCR-ABL transcripts. 220 77

The presence of Philadelphia chromosome t(9:22) is a hallmark of 95% of clinical cases of chronic myelogenous leukemia (CML) as well as 20% of adult acute lymphoblastic leukemia (ALL) and 5% of acute myeloid leukemia (AML). The product of t(9;22) is a fusion protein BCR-ABL. The fusion proteins of CML, ALL and AML have increased tyrosine kinase activity and show a transforming potential in vitro and in animal models. The shorter p190 protein is associated almost only with ALL and AML, while the protein p210 is present in both chronic phase and blast crisis of CML and also in 50% of Philadelphia-positive (Ph1+) ALL. In CML the transition from chronic phase to blast crisis is usually accompanied by additional genetic events, e.g. additional chromosomal abnormalities, and oncogene activation(s). The detailed understanding of molecular basis of CML, and Ph1+ ALL and AML provides highly sensitive molecular and serological methods to complement classical cytogenetics. The advantages and limitations of these techniques are described and discussed below.
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PMID:Molecular pathology of chronic myelogenous leukemia. 224 53

Double fluorescence in situ hybridization was used to detect Philadelphia (Ph) chromosomes in interphase nuclei and metaphases of patients with chronic myeloid leukemia. Application of cosmid probes for 3' ABL and 5' BCR sequences gave better results than libraries for chromosomes 9 and 22. The present approach may provide an alternative method for monitoring minimal residual disease in Ph+ CML patients.
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PMID:Detection of the Philadelphia chromosome in interphase nuclei. 226 53


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