Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.7.10.2 (focal adhesion kinase)
 44,029 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The chimeric BCR/ABL protein is characteristic of Philadelphia (Ph)+ leukemia because it is the direct product of the Ph translocation and it has been shown to play a causal role in the genesis of leukemia. The BCR/ABL protein exhibits a deregulated tyrosine-kinase activity capable of phosphorylating different cellular substrates in vivo and in vitro. CRKL, an adaptor protein consisting of SH2 and SH3 domains in the absence of a catalytic domain, is one potential in vivo substrate of BCR/ABL. Previous experiments have shown that CRKL is phosphorylated on tyrosine in the chronic myelogenous leukemia (CML) cell line K562 and that CRKL is a substrate for ABL and for BCR/ABL in COS-1 cells. In the current study, we show that in peripheral blood cells a direct correlation exists between the presence of BCR/ABL and the phosphorylation status of CRKL. In Ph- peripheral blood cells, CRKL is present only in the nonphosphorylated form. In contrast, all BCR/ABL+ CML and acute lymphoblastic leukemia patient samples examined showed clear tyrosine-phosphorylation of CRKL. This result strongly suggests that CRKL is a biologically significant substrate for BCR/ABL and is likely to play a major role in the development of Ph+ leukemia.
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PMID:Tyrosine phosphorylation of CRKL in Philadelphia+ leukemia. 752 85

We have used fluorescence in situ hybridisation (FISH) with a series of yeast artificial chromosome (YAC) clones that map to the long arm of chromosome 6 (6q) to define the region(s) of deletion in seven cases of non-Hodgkin's lymphoma (NHL), in which a deletion of 6q had been detected by conventional cytogenetics. The FISH analysis detected two regions of deletion: (i) A proximal region flanked by M6P1 (6q14-15) and FYN (6q21), containing D6S246, which was missing in all seven cases. This locus was also found to be deleted in all six cases of acute lymphoblastic leukaemia (ALL) studied previously. (ii) A second region of 6q, which was distal to 6q23.1 (D6S238) and included ESR (6q25.1) and D6S281 (6q27), which was shown to be present in all our cases of ALL, was found to be deleted in 4 of the 7 cases of NHL. Our results support the suggestion that tumour suppressor genes, involved in the pathogenesis of lymphoid malignancies, may be present within these regions.
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PMID:Common region of deletion on the long arm of chromosome 6 in non-Hodgkin's lymphoma and acute lymphoblastic leukaemia. 752 44

One of the earliest responses of T and B lymphocytes to stimulation through their antigen receptors is the activation of protein tyrosine kinases and the tyrosine phosphorylation of multiple cellular substrates. Here we describe a tyrosine kinase substrate, fakB, a putative homologue of the focal adhesion kinase pp125FAK. Tyrosine phosphorylation of fakB was rapidly augmented in human T and B cells following antigen receptor cross-linking with antibody, while pp125FAK was nonresponsive. Costimulation of the T-cell antigen receptor (TCR/CD3) with either the CD2 or CD4 costimulatory receptors induced synergistic fakB tyrosine phosphorylation in normal human T cells. Engagement of TCR/CD3 induced the stable association of fakB with ZAP-70, the TCR/CD3 sigma-chain-associated tyrosine kinase involved in antigen receptor-induced T-cell activation. In addition, preformed complexes of fakB and ZAP-70 were observed in T-cell leukemia lines. Phosphorylation of fakB on serine, threonine, and tyrosine residues was observed both in vivo and in vitro, where a functional increase of in vitro kinase activity was observed following TCR/CD3 stimulation. fakB is thus a focal adhesion kinase-related tyrosine kinase substrate that is differentially regulated from that of pp125FAK and likely plays a role in antigen-induced lymphocyte signaling.
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PMID:Lymphocyte antigen receptor activation of a focal adhesion kinase-related tyrosine kinase substrate. 752 94

Focal adhesion kinase (p125FAK; FAK) is a protein tyrosine kinase that is tyrosine-phosphorylated in response to v-src-mediated transformation, cell adhesion, and stimulation with neuropeptides. To elucidate a possible functional relationship between FAK and BCR-ABL oncoprotein detected in Philadelphia chromosome-positive (Ph+) leukemias, we investigated the tyrosine phosphorylation state of FAK in a murine growth factor-dependent cell line and in its stable human bcr-abl cDNA transfectant. In interleukin-3 (IL-3)-dependent NFS/N1.H7 cells, tyrosine phosphorylation of FAK was not detected after stimulation with either IL-3 or Steel factor (SLF), both of which involve Ras-mediated signaling pathways. However, stable gene transfection with p210bcr-abl cDNA into H7 cells made these cells growth factor-independent for proliferation and resulted in constitutive tyrosine phosphorylation and kinase activation of FAK. Constitutive phosphorylation and activation of FAK was also observed in all Ph+ leukemia cell lines examined--that is, K562, TS9;22, and YS9;22, which express p210BCR-ABL, and NALM-21 and OM9;22, which express p185BCR-ABL. Ph-negative (Ph-) cell lines, such as MO7e and JM, did not show any detectable tyrosine phosphorylation of FAK. FAK phosphorylation in BCR-ABL-expressing cells was inhibited in a dose-dependent manner by cytochalasin D, a reagent that disrupts the intracellular network of actin filaments. However, no suppression of kinase activity or protein expression of BCR-ABL was observed after treatment with cytochalasin D. A physical association between BCR-ABL and FAK was not apparent. These data suggest that BCR-ABL may be involved in the activation of FAK. Moreover, FAK may be distinct from components in Ras-mediated signaling cascades that are activated by stimulation of myeloid cells with various cytokines.
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PMID:Tyrosine phosphorylation and activation of focal adhesion kinase (p125FAK) by BCR-ABL oncoprotein. 755 24

We report two cases of acute lymphoblastic leukemia (ALL) with a late-appearing Philadelphia chromosome (Ph1), confirmed by the expression of BCR-ABL mRNA, using the reverse transcriptase/polymerase chain reaction (RT/PCR) technique. The first patient was a 10-year-old boy with precursor B cell type ALL-L1 (FAB classification). At diagnosis, no metaphase cells were found by chromosome analysis and BCR-ABL mRNA was not observed. At the beginning of relapse, which occurred after 7 months of complete remission, a normal karyotype was observed. At the terminal stage, leukemic cells with Ph1 and BCR-ABL mRNA for the P190 variety were observed. The second patient was a 12-year-old boy with immature T cell type ALL-L1. The metaphase cells showed a 9p- chromosome at diagnosis and Ph1 appeared in addition to 9p- at relapse. Hybrid mRNA for the P210 variety was detected only when Ph1 had developed. The blast cells with Ph1 were derived from the original leukemic clone through clonal evolution, since the same clonal rearrangements of IGH or TCRB were detected in leukemic cells obtained both at diagnosis and relapse in both patients. Thus, in both cases, Ph1 was detected only in the course of ALL along with expression of BCR-ABL mRNA. This observation also confirmed that, as in de novo Ph1-positive ALL, both the P190 and P210 varieties of BCR-ABL mRNA are observed in ALL with late-appearing Ph1.
Leukemia 1995 Oct
PMID:A late-appearing Philadelphia chromosome in acute lymphoblastic leukemia confirmed by expression of BCR-ABL mRNA. 756 11

Human T-cell-leukemia virus type I (HTLV-I) is the causative agent of adult T-cell leukemia/lymphoma (ATL) and tropical spastic paraparesis/HTLV-I-associated myelopathy (TSP/HAM). The different disease outcome may be attributable to subtle mutations leading to modification of viral tropism or infectivity. Initial attempts found a very high level of sequence conservation among all HTLV-I strains. However, only one complete proviral DNA sequence is reported from a TSP/HAM patient, with a provirus derived from immortalized lymphocytes, which might be expected to be a leukemogenic variant rather than a neurotropic one. We cloned and sequenced a complete HTLV-I provirus (HTLV-IBoi) derived from the uncultured lymphocytes of a sub-acute post-transfusional TSP/HAM patient with clonal integration of HTLV-I. HTLV-IBoi proviral genome is 9033 bp long, and its overall genetic organization is similar to that of the prototype HTLV-I(ATK), without major deletions or insertions. No premature termination codon was found in the 4 open reading frames of the pX region. Divergence at the nucleotide level of HTLV-IBoi from the reported full-length HTLV-I varies from 1 to 9.4%, and indicates that it corresponds to a cosmopolitan genotype. This study did not identify specific sequences associated with neurotropic strains.
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PMID:Human T-cell-leukemia virus type I in post-transfusional spastic paraparesis: complete proviral sequence from uncultured blood cells. 759 Dec 56

A patient with a chronic myeloproliferative disease associated with a 100% t(5;12) translocation was treated with 3 million U per day of IFN-alpha 2a. Besides being consistently Ph-negative, the search for BCR/ABL hybrid transcripts by means of RT-PCR was also negative. Total cytogenetic conversion to diploid hematopoiesis was obtained, but after discontinuation of IFN a 50% relapse of t(5;21) mitoses was found, and treatment was resumed. There is some degree of consensus that the mechanism by which IFN-alpha suppresses the Ph+ clone in CML consists in the restoration of normal adhesion of CML progenitors to the marrow stroma, by preventing transcription of the BCR/ABL mRNA, and hence expression of the p210 tyrosine kinase. However, if the 'faulty adhesion' hypothesis, and its correction by IFN-alpha, is to be considered correct, this case proves that it must include also Ph-negative, not BCR-ABL rearranged clonal myeloid proliferations.
Leukemia 1995 Jun
PMID:Chronic clonal myeloproliferative disease associated with a t(5;21) translocation. Complete but transient hematologic and cytogenetic remission induced by interferon-alpha. 759 88

We report the molecular cytogenetic analysis of a case of Philadelphia (Ph)-negative, BCR-positive chronic myeloid leukemia (CML) which appeared by conventional cytogenetics to have a t(6;9)(p23;q34) as the sole cytogenetic abnormality. Neither conventional nor pulse-field Southern blots detected any rearrangement of the DEK or CAN genes which are often fused in acute myeloid leukemia (AML) with t(6;9)(p23;q34). However, rearrangements of both BCR and ABL genes were detected. The breakpoint in BCR was located in the major translocation cluster region between exons b1 and b3. ABL rearrangements were detected with an ABL exon 1B probe and with a probe located 5' of the entire ABL gene. Comigration between the rearranged fragments obtained with M-bcr-5' and ABL exon 1B probes was observed, implying that the entire ABL gene was fused to the 5' part of the BCR gene. Fluorescence in situ hybridization (FISH) analyses using BCR and ABL probes showed that in 20% of metaphases BCR and ABL signals were present on one chromosome 6 at 6p23, whilst in 80% of metaphases BCR and ABL signals were identified on both copies of chromosome 6. Furthermore, FISH analysis with a whole-chromosome 22 paint demonstrated that chromosome 22 material was present on both copies of chromosome 6. These data indicate a complex Philadelphia translocation involving chromosome band 6p23 and duplication of the whole aberrant chromosome. The nature of the gene locus on 6p23, involved in this rearrangement, remains unknown. A similar translocation has been previously reported in a case of CML, which also lacked DEK and CAN gene rearrangements implying that abnormalities of 6p23 involving genes other than DEK may be a recurrent abnormality in CML.
Leukemia 1995 Jun
PMID:Molecular cytogenetics of chronic myeloid leukemia with atypical t(6;9) (p23;q34) translocation. 759 89

Sequence specificity of inhibitory effects of various BCR-ABL anti-sense oligodeoxynucleoside phosphorothioates (AS PS-ODN) on the proliferation of the chronic myeloid-leukemia cell line BV173 was examined. We confirmed that 26, 18, and 16mer B2A2 AS PS-ODN had strong inhibitory effects on the proliferation of BV173 cells with B2A2 mRNA expression, and that B3A2 AS PS-ODN were equally inhibitory when cultures were initiated at lower cell concentrations. However, at higher cell concentrations, the inhibitory effects by B3A2 AS PS-ODN were reduced and B2A2 AS PS-ODNs could suppress the proliferation of BV173 cells with much more relative sequence specificity. The 26mer B2A2 AS PS-ODN induced apoptosis of BV173 cells following reduction of BCR-ABL mRNA expression and p210 protein synthesis. Various sense (S), reverse order, and random sequences had no inhibitory effects except 16mer B2A2 S and B3A2 S that revealed significant suppressive effects. Furthermore, 26mer B3A2 AS also reduced B2A2 mRNA expression and p210 protein synthesis, while 16mer S sequences did not. These results suggest that B2A2 AS may be cross-reactive with B3A2 AS on the growth suppression of CML cells under certain culture conditions, possibly due to their partial hybridization to the ABL portion of the target mRNA, although other non-sequence-specific mechanisms are also possible.
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PMID:Sequence specificity on the growth suppression and induction of apoptosis of chronic myeloid leukemia cells by BCR-ABL anti-sense oligodeoxynucleoside phosphorothioates. 760 69

Infusions of large numbers (> 10(8)/kg) of donor leukocytes can induce remissions in patients with chronic myeloid leukemia (CML) who relapse after marrow transplantation. We wanted to determine if substantially lower numbers of donor leukocytes could induce remissions and, if so, whether this would reduce the 90% incidence of graft-versus-host disease (GVHD) associated with this therapy. Twenty-two patients with relapsed CML were studied: 2 in molecular relapse, 6 in cytogenetic relapse, 10 in chronic phase, and 4 in accelerated phase. Each patient received escalating doses of donor leukocytes at 4- to 33-week intervals. Leukocyte doses were calculated as T cells per kilogram of recipient weight. There were 8 dose levels between 1 x 10(5) and 5 x 10(8). Lineage-specific chimerism and residual leukemia detection were assessed using sensitive polymerase chain reaction (PCR) methodologies. Nineteen of the 22 patients achieved remission. Remissions were achieved at the following T-cell doses: 1 x 10(7) (n = 8), 5 x 10(7) (n = 4), 1 x 10(8) (n = 3), and 5 x 10(8) (n = 4). To date, 15 of the 17 evaluable patients have become BCR-ABL negative by PCR. The incidence of GVHD was correlated with the dose of T cells administered. Only 1 of the 8 patients who achieved remission at a T-cell dose of 1 x 10(7)/kg developed GVHD, whereas this complication developed in 8 of the 11 responders who received a T-cell dose of > or = 5 x 10(7)/kg. Three patients died in remission, 1 secondary to marrow aplasia, 1 of respiratory failure and 1 of complications of chronic GVHD. Sixteen patients who were mixed T-cell chimeras before treatment became full donor T-cell chimeras at the time of remission. Donor leukocytes with a T-cell content as low as 1 x 10(7)/kg can result in complete donor chimerism together with a potent graft-versus-leukemia (GVL) effect. The dose of donor leukocytes or T cells used may be important in determining both the GVL response and the incidence of GVHD. In many patients, this potent GVL effect can occur in the absence of clinical GVHD.
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PMID:Adoptive immunotherapy evaluating escalating doses of donor leukocytes for relapse of chronic myeloid leukemia after bone marrow transplantation: separation of graft-versus-leukemia responses from graft-versus-host disease. 763 30


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