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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 Ph chromosome was the first specific karyotype abnormality associated with a particular neoplastic disease in humans. For many years it was suspected that chromosome abnormalities might cause cancer by alteration of specific genes or their expression. Significant recent developments in our understanding of the molecular consequences of the Ph translocation strengthen that assumption. The Ph translocation generates a hybrid gene consisting of 5' regulatory, promotor, and exon sequences of the bcr gene on chromosome 22 fused to 3' exons and polyadenylation/termination sequences of the ABL proto-oncogene from chromosome 9. It is well established that fusion of bcr and abl genes plays a crucial role in the pathogenesis of CML and ALL. Molecular methods can therefore be used as diagnostic tools to detect the Ph chromosome. Presently, the model of oncogenesis provided by our knowledge of how the abl proto-oncogene becomes activated as a result of the Ph translocation is one of the clearest models of oncogene activation. Despite the progress made, many areas remain to be explored. One important question is, how the hybrid protein is involved in leukemia. Research aimed at investigating the normal function of abl and bcr may be important in efforts to understand their abnormal functioning in leukemia and to increase our understanding of the disease.
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PMID:Molecular insights into the Philadelphia translocation. 205 Jun

A patient with chronic myeloid leukemia secreted an antibody to blood group glycosyltransferases after ABO-incompatible bone marrow transplantation (B recipient/O donor). Peripheral B lymphocytes from the recipient were transformed with Epstein-Barr virus, and then fused by polyethylene glycol with mouse myeloma cell line P3-X63/Ag8.653. After the cloning of the hybridoma cells, a cell line which produced human IgM antibody to blood group glycosyltransferases was established. The antibody completely neutralized B transferase activity at low concentration, while a larger amount of immunoglobulins was required to neutralize A transferase activity.
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PMID:Monoclonal antibody to blood group glycosyltransferases, produced by hybrids constructed with Epstein-Barr-virus-transformed B lymphocytes from a patient with ABO-incompatible bone marrow transplant and mouse myeloma cells. 217 79

In the majority of Philadelphia (Ph)-positive chronic myeloid leukemia (CML) patients, the c-abl gene is fused to the bcr gene, resulting in the transcription of an 8.5 kb chimeric bcr-abl mRNA, which is translated into a p210bcr-abl fusion protein. In about 50% of the Ph-positive acute lymphoid leukemias (ALL), the bcr-abl gene fusion is identical to CML, while in 50% an alternative fusion between these two genes occurs, in which the central bcr-sequences are absent. This results in transcription of a 7 kb bcr-abl mRNA, encoding a P190bcr-abl fusion protein. Cloning and sequencing of the chimeric part of bcr-abl cDNAs from two Ph-positive CML patients in chronic phase showed that in one patient, as in the Ph-positive ALL, all central bcr sequences are absent, while in the other patient, part of the bcr central sequences are deleted. Therefore, we speculate that the presence of the 7 kb chimeric ALL type mRNA in one of the patients is not sufficient to drive an acute rather than a chronic leukemic process in this case. The deletions of the central bcr-sequences described here define the minimal sequence requirement of the bcr-abl fusion gene in CML patients so far.
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PMID:Chronic myeloid leukemia may be associated with several bcr-abl transcripts including the acute lymphoid leukemia-type 7 kb transcript. 220 36

The Philadelphia (Ph1) chromosome in chronic myelogenous leukemia (CML) involves reciprocal translocation of the bcr gene and the c-abl oncogene. The fused bcr/abl gene is transcribed into two types of chimeric mRNA. By means of a combined method of S1 nuclease protection and polymerase chain reaction, we amplified sequences representative of the chimeric bcr/abl transcripts. Only 5 micrograms of total cellular RNA is needed and the chimeric bcr/abl message can be detected at a dilution of 1:100,000. We also detected residual chimeric bcr/abl transcripts in the remission samples from two Ph1-positive CML patients. This technique has the potential to identify a subpopulation of Ph1-positive CML patients in remission who are at high risk of relapse.
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PMID:Detection of minimal residual bcr/abl transcripts by a modified polymerase chain reaction. 245 51

The Philadelphia chromosome is present in more than 95% of chronic myelogenous leukemia patients and in up to 25% of patients with acute lymphocytic leukemia. The major consequence of the aberration is the fusion of the ABL and BCR genes. The position of the breakpoint on chromosome 22 determines which species of the potential three fused mRNAs and proteins will be synthesized. We have used the polymerase chain reaction (PCR) to detect these mRNAs in 53 patients and cell lines and found that around 20% contain simultaneously two BCR-ABL mRNAs, presumably due to a process of alternative splicing. The results also indicate that most patients in lymphocytic blast crisis of CML contain the mRNA in which bcr exon 2 is linked to ABL exon II. Finally, we identified, cloned, and characterized a BCR-related sequence that originated from mRNA.
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PMID:Analysis of BCR-ABL mRNA in chronic myelogenous leukemia patients and identification of a new BCR-related sequence in human DNA. 248 58

Human chronic myelogenous leukemia is characterized by a reciprocal translocation between chromosomes 9 and 22. This results in the transfer of the c-abl protooncogene from chromosome 9 into the bcr gene on chromosome 22. The purpose of this study was to characterize the bcr and related gene products. Antibodies were raised against a fused trpE-bcr protein induced in a bacterial expression vector. Immunoprecipitation with the monoclonal and polyclonal antibodies of metabolically [35S]methionine labeled leukemic cell lines shows a 210, 160 and 130 Kda protein in Philadelphia positive cells containing the bcr-abl fused transcript. Only the 160 and 130 Kda were present in the Philadelphia negative cells. In vitro kinase assay shows that the 130 Kda protein is a phosphoprotein mainly phosphorylated on serine. Partial proteolysis indicates that the p210 and p130 share common domains. In subcellular fractionation experiments, the p130 is colocalized with the p210 bcr-abl in the cytoplasmic fraction. Together with the mapping of 4 distinct bcr related loci our data suggest that the 130 Kda phosphoprotein belongs to a wider family of bcr related gene products.
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PMID:Identification of a 130 Kda bcr related gene product. 249 32

The bcr gene plays a critical role in the pathogenesis of two human leukemias associated with the Philadelphia chromosome: chronic myelogenous leukemia (CML) and acute lymphoblastic leukemia (ALL). In both instances a chimeric gene, formed between bcr and the abl protooncogene, results in expression of fused bcr-abl proteins with tyrosine kinase activity. There is controversy regarding the normal gene products of bcr. We investigated this problem by several techniques and found proteins of 190/185, 155, 135, 125, 108, 83 and 47 kDa in several human cell lines by immunoprecipitation with two distinct site-directed anti-bcr antibodies termed anti-bcr(738-753) and anti-bcr(898-911). The 190/185, 155, 125 and 108 kDa proteins were consistently detected by anti-bcr(898-911) antibodies by immunoblotting. Antibodies pre-reacted with excess bcr peptide did not detect these proteins. These proteins were labeled with [32P]orthophosphate in vivo and in vitro by [gamma 32P]ATP in immune complex kinase assays performed with anti-bcr antibodies indicating that these proteins are phosphorproteins. Following labeling in kinase assays, phosphoamino acid analyses detected both phosphoserine and phosphothreonine. In structural studies using one dimensional peptide maps derived by partial V8 protease treatment, the 185, 155, 135, 125 and 108 kDa proteins shared several peptide fragments but contained unique fragments as well. Similarly 2-dimensional maps of proteins labeled in the kinase assay exhaustively digested with trypsin, revealed homology between the 155, 135, 125, 108, and 83 kDa proteins. bcr proteins sedimented in glycerol gradients as putative complexes detected in the cytoplasm of the cell. A 47 kDa protein as well as the recently identified Ph-P53 protein appeared to be associated with bcr proteins based on their co-sedimentation in glycerol gradients and co-immunoprecipitation with several different anti-bcr antibodies. None of the proteins exhibited a precursor-product relationship in pulse-chase experiments conducted with [35S]methionine. We conclude that human cells express several different bcr gene products ranging in size from 190 to 83 kDa, and that these proteins can form specific intracellular cytoplasmic complexes with other cellular proteins.
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PMID:Characterization of bcr gene products in hematopoietic cells. 264 52

Results of our study on the activation of N-ras oncogene by point mutation in human leukemia and myelodysplastic syndrome have been described in this article. Point mutation was observed mainly on the 12th, 13th and 61st amino acid codon of ras genes. Therefore, oligomers containing mutations at these codons were used as probes for dot blot analysis of DNA derived from patient's bone marrow cells or leukemia cells. Polymerase chain reaction technique was used to amplify the DNA of ras genes containing 12th, 13th and 61st codons. By this technique, sensitivity of the method to detect the point mutations in ras oncogene was remarkably increased. Detection of the mutation in ras gene is considered to be very useful for the diagnosis, determination of remission and finding of relapse at an early stage. Study on the fused gene of bcr-abl, its mRNA and protein in chronic myelogenous leukemia is a good and reliable method to prove the existence of Ph1 positive chromosome by gene technology. Identification of the Ph1 acute lymphoblastic leukemia (ALL) has become possible by studying abl oncogene in Ph1 positive ALL. This method can be used also for the diagnosis of Ph1 ALL.
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PMID:[Oncogenes in human leukemia]. 265 Jun 33

In chronic myeloid leukemia and some cases of acute lymphoblastic leukemia, a 9;22 chromosome translocation has fused most of the c-abl oncogene to a gene designated bcr. To explore in vivo the biological effects of the chimeric gene, we introduced a facsimile of the translocation product, a bcr-v-abl gene, into the mouse germ line under the control of the immunoglobulin heavy-chain enhancer or a retroviral long terminal repeat. Some transgenic mice bearing either construct developed clonal lymphoid tumors. T lymphomas predominated, but some pre-B lymphomas developed. The transgenes were expressed in the tumors but not detectably in the lymphoid tissues of nontumorous transgenic animals, implying that transcription is activated by a low-frequency somatic event. These results demonstrate that bcr-v-abl is tumorigenic in vivo and provide a new animal model for lymphomagenesis.
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PMID:A bcr-v-abl oncogene induces lymphomas in transgenic mice. 278 35

Peripheral blood mononuclear cells from a patient with chronic myelogenous leukemia (CML), in remission, were depleted of CD8-positive T-cells and cultured with Epstein-Barr virus. Four of 20 cultures (20%) secreted human IgG antibodies selectively reactive with the cell surfaces of certain human leukemia cell lines. Three polyclonal, Epstein-Barr virus-transformed, B-cell lines were expanded and fused with the human-mouse myeloma analogue HMMA2.11TG/O. Antibody from secreting clones HL 1.2 (IgG1), HL 2.1 (IgG3), and HL 3.1 (IgG1) have been characterized. All three react with HL-60 (promyelocytic), RWLeu4 (CML promyelocytic), and U937 (monocytic), but not with KG-1 (myeloblastic) or K562 (CML erythroid). There is no reactivity with T-cell lines, Burkitt's cell lines, pre-B-leukemia cell lines, or an undifferentiated CML cell line, BV173. Leukemic cells from two of seven patients with acute myelogenous leukemia and one of five with acute lymphocytic leukemia react with all three antibodies. Normal lymphocytes, monocytes, polymorphonuclear cells, red blood cells, bone marrow cells, and platelets do not react. Samples from patients with other diverse hematopoietic malignancies showed no reactivity. Immunoprecipitations suggest that the reactive antigen(s) is a lactoperoxidase iodinatable series of cell surface proteins with molecular weights of 42,000-54,000 and a noniodinatable protein with a molecular weight of 82,000. Based on these data these human monoclonal antibodies appear to react with myelomonocytic leukemic cells and may detect a leukemia-specific antigen or a highly restricted differentiation antigen.
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PMID:Human monoclonal antibodies reactive with human myelomonocytic leukemia cells. 292 15


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