Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0023418 (leukemia)
 93,477 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

Chronic myelogenous leukemia (CML) is characterized by a translocation involving the c-abl protein-tyrosine kinase gene. A chimeric mRNA is formed containing sequences from a chromosome 22 gene (bcr) at its 5' end and all but the variable exon 1 of c-abl sequence. The product of this mRNA, p210bcr-abl, has constitutively high protein-tyrosine kinase activity. We examined K562 cells and other lines established from CML patients for the presence of phosphotyrosine (P-Tyr)-containing proteins which might be p210bcr-abl substrates. Two-dimensional gel separation of 32P-labeled proteins followed by phosphoamino acid analysis of 25 phosphoproteins, which comprised the major alkali-stable phosphoproteins, indicated that three related proteins of 41 kDa are the most prominent P-Tyr-containing proteins detected by this method. The 41-kDa phosphoproteins are found in two other CML lines that we examined but not in lines of similar lineage isolated from patients with distinct leukemic disease. A protein that comigrates with the major form of pp41 (pp41A) and contains P-Tyr is also found in murine fibroblasts and B-lymphoid cells transformed by Abelson murine leukemia virus, which encodes the v-abl protein, and in platelet-derived growth factor-treated fibroblasts, in which it has been described previously. We analyzed three pairs of Epstein-Barr virus-immortalized B-cell lines from individual CML patients and found that only the lines in which active p210bcr-abl was present contained detectable pp41. We also performed immunoblotting with anti-P-Tyr antibodies on the same CML cell lines and detected at least four other putative substrates of p210bcr-abl, which were undetected with use of the two-dimensional gel technique.
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PMID:A 41-kilodalton protein is a potential substrate for the p210bcr-abl protein-tyrosine kinase in chronic myelogenous leukemia cells. 154 12

The Philadelphia chromosome, originally thought to be associated solely with chronic myelogenous leukemia (CML), has since been identified in acute leukemias and in some cases of lymphoma. The Philadelphia chromosome results from reciprocal translocation of genetic material between chromosome 9 and 22 involving the c-abl and BCR genes respectively. Southern blot analysis of the BCR genes was carried out on biopsy specimens from 49 patients presenting with malignant lymphoma without a previously documented CML phase. In two patients, BCR gene rearrangements were detected in the malignant lymph nodes but not in the bone marrow samples. A third patient showed BCR gene rearrangements in the bone marrow but not in the lymph node. From this limited study, it seems that the overall incidence of BCR gene rearrangement in malignant lymphoma is similar to that observed in adult AML.
Leukemia 1992 Jun
PMID:Rearrangement of BCR genes in malignant lymphoma. 160 94

Tyrosine protein kinases (TPK) help regulate cellular growth and differentiation. Several proto-oncogenes encode for protein products with associated tyrosine kinase activity. An assay for TPK activity was performed in cell extracts using a synthetic peptide substrate and [32P] adenosine triphosphate (ATP). TPK activity was elevated in K-562 cells, which possess an amplified c-abl oncogene, compared to normal blood mononuclear cells (K-562 = 9.37 +/- 1.72 [mean +/- standard deviation] pmol ATP/10(6) cells/min; normal = 1.14 +/- 0.46, p less than 0.01). TPK activity was measured in peripheral blood mononuclear cells from patients with hairy cell leukemia (HCL), myelomonocytic leukemia (MOL), acute myeloblastic leukemia (AML), and chronic lymphocytic leukemia (CLL). In patients with clinically active disease, elevated TPK activity was measured in mononuclear cells from five HCL patients (range 3.76-24.15) and from seven MOL patients. These elevated levels appeared to parallel disease activity, as low levels of TPK activity were measured in patients with inactive (treated) disease. Low levels of TPK were measured in mononuclear cells from active AML and CLL patients. Elevated TPK levels in patients with HCL and MOL may reflect the overexpression of a proto-oncogene or increased growth factor activity in immature or rapidly dividing leukemic cells. Serial TPK levels in HCL and MOL patients correlated with change in disease activity.
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PMID:Increased tyrosine protein kinase activity in hairy cell and monocytic leukemias. 160 67

By using antisense oligomers the functional role of the c-abl proto-oncogene in the in vitro growth of bone marrow hematopoietic progenitors from normal subjects and patients with chronic myelogenous leukemia (CML) has been evaluated. Light density bone marrow cells (LDBMs) were depleted of adherent cells, pre-incubated for 15 h with the appropriate oligomer at a concentration of 14 microns, and then plated in methylcellulose for the evaluation of colony formation. Both anti-exon Ia and anti-exon Ib antisense oligomers produced a significant inhibition of normal day 14 CFU-GM growth in vitro (n = 5, 41 +/- 11%, and 36 +/- 7%, respectively; p less than 0.01). In contrast, normal BFU-E growth was not significantly influenced by antisense oligomers (n = 5, 14 +/- 21% and 7 +/- 19%, respectively; p less than 0.05). These findings were confirmed by plating CD34 positive progenitors. When interleukin 3 (IL-3) (100 ng/ml) was added to the culture medium during the preincubation of LDBMCs, the inhibitory effects of antisense oligomers on normal CFU-GM growth were abolished. Seven patients with CML were also studied, all of whom had cytogenetic evidence of 100% clonal hematopoiesis. In five patients in the chronic phase, antisense oligomers were inhibitory on in vitro growth of both day 14 CFU-GM (37 +/- 20% and 37 +/- 15%, p less than 0.05) and BFU-E (45 +/- 15% and 41 +/- 11%, p less than 0.05), and this inhibition was not removed by pre-incubation with IL-3. No significant effect was observed on cluster or colony formation in two patients with CML in accelerated or blastic phase, and on in vitro growth of clonogenic cells from the Ph1-positive K-562 cell line. These findings (i) confirm previous observations showing a lineage specific requirement of c-abl function in normal hematopoiesis, and (ii) suggest that the residual c-abl expression has a role in chronic phase CML hematopoiesis, as its inhibition impairs both myeloid and erythroid colony formation in vitro.
Leukemia 1992 Jan
PMID:c-abl function in normal and chronic myelogenous leukemia hematopoiesis: in vitro studies with antisense oligomers. 173 9

The cellular gene c-abl is the normal homologue of the transforming gene (v-abl) within the genome of the Abelson leukaemia virus. The cDNA sequence coding for the cellular form of the murine abl gene (c-abl type IV) has been inserted into the baculovirus transfer vector, pAc36C, so that the c-abl gene is under the control of the polyhedrin promoter of Autographa californica nuclear polyhedrosis virus (AcNPV). Spodoptera frugiperda cells infected with the recombinant transfer vector in the presence of wild type AcNPV DNA yielded recombinant, polyhedrin negative virus that expressed moderate levels of the c-Abl protein (representing approx. 0.5-1% of the stained cellular proteins as determined by densitometric scanning). The insect derived c-Abl protein was compared to the P210-BCR/ABL protein from K562 cells, a cell line derived from a patient with chronic myelogenous leukaemia. Antibodies raised against synthetic peptides based on c-abl encoded peptides react with the insect derived c-Abl. In addition, the baculovirus derived c-Abl protein has a tyrosine kinase activity as demonstrated by phosphorylation of a synthetic polypeptide and also by autophosphorylation. Phosphoamino acid analysis of immunoprecipitated, autophosphorylated baculovirus derived c-Abl protein indicates that the majority of label incorporated is on the tyrosine residues. Immunofluorescence microscopy has been used to show that the majority of the c-Abl protein expressed in cells infected with recombinant virus is located in the nuclear and plasma membranes.
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PMID:Expression of the mouse c-abl type IV proto-oncogene product in the insect cell baculovirus system. 173 71

A female patient with precursor B-cell acute lymphoblastic leukemia (precursor B-ALL) was analyzed cytogenetically. Karyotyping of the leukemic cells showed a Philadelphia chromosome (Ph1), and also showed a translocation between 2p13 and 14q32, which is thought to be specific for children with B-cell chronic lymphocytic leukemia. DNA analysis with both conventional and pulsed-field gel electrophoresis revealed the rearrangement of the c-abl gene, the BCR gene outside the 5.8 kb breakpoint cluster region (bcr or M-BCR), and the comigration of an abnormal Not I pHabl 5' and 3'-bcr fragment, indicating the presence of BCR/c-abl recombination. The JH gene was rearranged, but the JK gene showed a germline configuration, as with previously reported cases with a t(2;14). This case is the first report of a patient with Ph1-positive precursor B-ALL, in whom a specific translocation t(2;14)(p13;q32) is found simultaneously.
Leukemia 1991 Aug
PMID:Philadelphia chromosome positive precursor B-cell acute lymphoblastic leukemia with a translocation t(2;14)(p13;q32). 188 25

Using the polymerase chain reaction and Southern blot analysis the expression was detected of a bcr-abl mRNA lacking abl exon a2. This was due to a corresponding unusual localization of the breakpoint in the c-abl gene and was seen in a patient with Philadelphia (Ph) chromosome positive chronic myelogeneous leukemia in chronic phase. This type of mRNA has been described only once before in two Ph-positive acute lymphoblastic leukemia patients, by Soekarman et al. (1). The abl exon a2 sequences, which are missing in the three reported patients, code for a part of the SH3 region of the abl protein, which is supposed to be involved in negative regulation of the kinase domain. The clinical significance of this finding is discussed.
Leukemia 1991 Jun
PMID:bcr-abl mRNA lacking abl exon a2 detected by polymerase chain reaction in a chronic myelogeneous leukemia patient. 793 77

The c-abl gene, originally identified as the cellular homolog of the transforming gene of the Abelson murine leukemia virus, encodes a protein-tyrosine kinase of unknown function that is expressed in all mammalian tissues. We have previously described the introduction of a mutation in the c-abl gene into the mouse germline via targeted gene disruption of embryonic stem cells. We now show that mice homozygous for this mutation are severely affected, displaying increased perinatal mortality, runtedness, and abnormal spleen, head, and eye development. We have examined components of the immune system and have found major reductions in B cell progenitors in the adult bone marrow, with less dramatic reductions in developing T cell compartments.
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PMID:Mice homozygous for the ablm1 mutation show poor viability and depletion of selected B and T cell populations. 206 53

The Philadelphia (Ph) chromosome translocation, t(9:22) (q34;q11) is found in some acute lymphoid leukaemias (ALL) and acute myeloid leukaemias (AML). Although cytogenetically all pH chromosomes appear similar, the 22q11 breakpoints found in acute leukaemias are of two kinds, those within the major breakpoint cluster region (Mbcr-1) of the BCR gene as found in chronic myelogenous leukaemia (CML), and those within the first intron of this gene. In the former group the molecular events are the same as those found in CML, p210 bcr-abl, encoded by 8.5 kb mRNA; however, a new aberrant protein, p190 bcr-abl, is found in the latter group. Ph translocation is also found in a few cases with malignant lymphoma, but it has not been characterized at the molecular level. We describe here a non-Hodgkin's lymphoma case with primary splenic presentation, which showed a complex Ph translocation. Neoplastic cells were of a B-cell origin (HLA-DR+, sIgM+, sIg lambda +, CALLA-). Molecular studies revealed the expression of p190 bcr-abl with no Mbcr-1 rearrangement. Our case indicates that the same Ph translocation as seen in acute leukaemias can be found in haematologic disorders other than leukaemias, suggesting that a c-abl gene activating mechanism may be involved in the pathogenesis of wide spectrum of haematologic malignancies.
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PMID:Philadelphia chromosome positive B-cell type malignant lymphoma expressing an aberrant 190 kDa bcr-abl protein. 209 24


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