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)

Breakpoints on chromosome 22 in the translocation t(9;22) found in Philadelphia positive acute lymphoblastic leukaemia patients fall within two categories. In the first the breakpoint is localized within the breakpoint cluster region of the BCR gene, analogous to the chromosome 22 breakpoint in chronic myeloid leukaemia. The second category has a breakpoint 5' of this area, but still within the BCR gene. We have previously shown that these breakpoints occur within the first intron of the BCR gene and cloned the 9q+ junction from such a patient. We have now determined the sequences around the breakpoints on both translocation partners from this patient as well as the germline regions. The chromosome 9 ABL sequence around the breakpoint shows homology to the consensus Alu sequence whereas the chromosome 22 BCR sequence does not. At the junction there is a 6 bp duplication of the chromosome 22 sequence which is present both in the 9q+ and in the 22q- translocation products. Possible mechanisms for the generation of the translocation are discussed.
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PMID:Nucleotide sequence of both reciprocal translocation junction regions in a patient with Ph positive acute lymphoblastic leukaemia, with a breakpoint within the first intron of the BCR gene. 291 61

A probe derived from the 3' region of the BCR gene (breakpoint cluster region gene) detects four distinct loci in the human genome. One of the loci corresponds to the complete BCR gene, whereas the others contain a 3' segment of the gene. After HindIII cleavage of human DNA, these four loci are detected as 23-, 19-, 13-, and 9-kilobase-pair fragments, designated BCR4, BCR3, BCR2, and BCR1, respectively, with BCR1 deriving from the original complete BCR gene. All four BCR loci segregate 100% concordantly with human chromosome 22 in a rodent-human somatic cell hybrid panel and are located at chromosome region 22q11.2 by chromosomal in situ hybridization. The BCR2 and BCR4 loci are amplified in leukemia cell line K562 cells, indicating that they fall within the amplification unit that includes immunoglobulin lambda light chain locus (IGL) and ABL locus on the K562 Philadelphia chromosome (Ph1); additionally, in chronic myelogenous leukemia-derived mouse-human hybrids retaining a Ph1 chromosome in the absence of the 9q+ and normal chromosome 22, BCR2 and BCR4 loci are retained, whereas the 3' region of BCR1 and the BCR3 locus are lost, indicating that BCR3 is distal to BCR1 on chromosome 22. Similarly, in mouse-human hybrids retaining a Ph1 chromosome derived from an acute lymphoblastic leukemia-in the absence of the 9q+ and 22, only BCR2 and BCR4 loci are retained, indicating that the breakpoint in this acute lymphoblastic leukemia, as in chronic myelogenous leukemia, is proximal to the BCR1 3' region, but distal to the IGLC locus and the BCR2 and BCR4 3' loci. Thus, the order of loci on chromosome 22 is centromere----BCR2, BCR4, and IGL----BCR1----BCR3----SIS, possibly eliminating BCR2 and BCR4 loci as candidate targets for juxtaposition to the ABL gene in the acute lymphoblastic leukemia Ph1 chromosome.
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PMID:Mapping of four distinct BCR-related loci to chromosome region 22q11: order of BCR loci relative to chronic myelogenous leukemia and acute lymphoblastic leukemia breakpoints. 311 59

The Philadelphia (Ph) translocation t(9;22)(q34;q11) occurs frequently in chronic myeloid leukemia (CML) but is less common in acute lymphoblastic leukemia (ALL) and rare in acute myeloid leukemia (AML). In most cases of CML and some cases of Ph+ ALL the protooncogene ABL from 9q34 is translocated to the breakpoint cluster region (bcr) of the BCR gene at 22q11 to form a chimeric gene encoding a novel 210-kd protein (P210 BCR-ABL) with enhanced tyrosine kinase activity. In other patients with Ph+ ALL and Ph+ AML, the breakpoint probably occurs in the first intron of the BCR gene; this results in a smaller chimeric gene which encodes a P190 BCR-ABL. We studied a patient with AML (FAB M6) arising de novo who had a "masked" Ph chromosome in association with extensive karyotypic changes. The leukemic cells initially showed rearrangement of the bcr, presence of a hybrid mRNA, and expression of the P210 BCR-ABL. These changes were absent in remission. These results support the concept that the BCR-ABL chimeric gene plays a crucial role in leukemogenesis but suggest that factors other than the position of the breakpoint in the BCR gene determine the lineage of the target cell for malignant transformation.
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PMID:Rearrangement of the breakpoint cluster region and expression of P210 BCR-ABL in a "masked" Philadelphia chromosome-positive acute myeloid leukemia. 317 49

The Philadelphia chromosome (Ph1) of chronic myelogenous leukemia (CML) contains sequences from chromosome 9, including the ABL protooncogene, that have been translocated to the breakpoint cluster region (bcr) of chromosome 22, giving rise to a bcr-ABL fusion gene, whose product has been implicated in the genesis of CML. Although chromosome 22 translocation breakpoints in CML virtually always occur within the 5.8-kilobase (kb) bcr, chromosome 9 breakpoints have been identified within the known limits of ABL in only a few instances. For a better understanding of the variability of the breakpoints on chromosome 9, we studied the CML cell line BV173. Using pulsed-field gel electrophoresis (PFGE), large-scale maps of the t(9;22) junctions were constructed. The chromosome 9 breakpoint was shown to have occurred within an ABL intron, 160 kb upstream of the v-abl homologous sequences, but still 35 kb downstream of the 5'-most ABL exon. bcr-ABL and ABL-bcr fusion genes were demonstrated on the Ph1 and the 9q+ chromosomes, respectively; both of these genes are expressed. These results suggest that the 9;22 translocation breakpoints in CML consistently occur within the limits of the large ABL gene. RNA splicing, sometimes of very large regions, appears to compensate for the variability in breakpoint location. These studies show that PFGE is a powerful new tool for the analysis of chromosomal translocations in human malignancies.
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PMID:Long-range mapping of the Philadelphia chromosome by pulsed-field gel electrophoresis. 342 29

hLH-2, a transcription factor that contains double cysteine rich regions (LIM motifs) and a homeobox (Hox) DNA-binding domain shows aberrant high expression in all cases of chronic myelogenous leukemia (CML). This gene has been mapped to the chromosome 9q33-34.1, the same region as the reciprocal translocation that creates the breakpoint cluster region (BCR)-ABL chimera of the Philadelphia chromosome (Ph'). To investigate the possible involvement between the BCR-ABL fusion gene and hLH-2 in the pathogenesis of CML, an hLH-2-negative CML cell line, JK-1 that carries double Ph' chromosomes, was examined. Like other CML cells, high BCR-ABL fusion mRNA levels are expressed, but no transcript of hLH-2 was detected in JK-1 cells as determined by reverse transcriptase-polymerase chain reaction (RT-PCR). Compared with the CML cell line, K-562, an additional rearrangement of the BCR gene was observed in JK-1 as determined by Southern blot hybridization; however, the hLH-2 gene was normal. These findings raise interesting questions about the possible roles of either the abnormal BCR gene or other genetic events such as the complex chromosomal abnormalities that result in hLH-2 being turned off in JK-1 cells.
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PMID:A structurally abnormal breakpoint cluster region gene in a transcription factor, hLH-2-negative human leukemia cell line. 760 May 33

In chronic myeloid leukemia (CML) the proto-oncogene c-abl from chromosome 9 q34 is translocated to the breakpoint cluster region (bcr) gene on chromosome 22 q11. This translocation results in a BCR-ABL fusion gene, which encodes chimeric fusion oncoproteins p210BCR-ABL. Here we demonstrate that a peptide with joining region sequence ATGFKQSSKALQRPVAS (eight amino acids (aa) encoded by BCR exon 3; one novel lysine, encoded by the fusion codon; eight aa encoded by ABL exon 2) is immunogenic to human T cells. Primary immune response induction with this peptide resulted in a HLA DR2(DRB1*1501) restricted CD4+ BCR-ABL peptide specific T cell line P1. Responses of P1 were negatively affected by individual aa replacement by alanine at eight aa positions within the 17mer peptide (F4, K5, Q6, K9, L11, Q12, R13, P14). These findings were supported by experiments with a panel of overlapping 11mer b3a2 peptides. Only two of these peptides with an aa sequence encompassing all residues which could not be replaced by alanine induced P1 proliferation. Since presentation of cytosolic oncoproteins as peptides by DR molecules has been observed, the present findings provide a possible explanation for post interferon-alpha persisting remissions in spite of the presence of BCR-ABL PCR positive progenitors.
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PMID:Recognition of peptides corresponding to the joining region of p210BCR-ABL protein by human T cells. 764 23

A newly established human leukemia cell line, OM9;22, is reported, with B-precursor immunophenotype (CD10+ CD19+ CD22+ HLA- DR+ C mu-) and CD13 antigen, originated from a 19-year-old female patient with Philadelphia (Ph) chromosome-positive acute lymphoblastic leukemia (ALL). The OM9;22 cells carry a Philadelphia (Ph) translocation and hybrid message detected by a minor-breakpoint cluster region (BCR) exon 1/ABL exon 2 junctional probe using reverse transcriptase polymerase chain reaction. The genetic alterations are consistent with those observed in the donor's leukemia cells, allowing us to conclude that this cell line is a minor-BCR rearranged Ph-positive ALL (Ph+ ALL). Colony formation of the OM9;22 cells in methylcellulose culture is enhanced by the addition of human interleukin 7 (IL-7). In liquid culture, more than 80% of IL-7-treated OM9;22 cells express CD20 antigen but fail to express surface immunoglobulins or cytoplasmic mu-chain, indicating that the cells have a potential of limited maturation by IL-7. By contrast, IL-4 suppresses the colony formation of the OM9;22 cells. These findings suggest that this cell line might be a model of B-precursor human leukemia with proliferative capability by IL-7.
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PMID:Interleukin-7 enhances colony growth and induces CD20 antigen of a Ph+ acute lymphoblastic leukemia cell line, OM9;22. 768 4

In order to understand better the mechanism of translocation between the BCR and ABL genes in CML, we have exploited a 'bubble PCR' technique to clone genomic breakpoints. BCR-ABL junction fragments were successfully amplified and sequenced in 14/32 (43%) patients tested. Breakpoints were dispersed throughout the major breakpoint cluster region without any clustering or hot spots. In three cases Alu sequences were found at or near the breakpoint on the ABL side of the translocation but no other obvious sequence homologies were found either in BCR or ABL. The translocation event was characterized further in three other patients by amplifying the reciprocal ABL-BCR junction on the 9q+ chromosome and also normal ABL around breakpoints. In two of these patients a few nucleotides of BCR and ABL were either duplicated or deleted on translocation, suggesting that staggered cuts had been made in the DNA strand prior to recombination. In the third patient 50 bp of ABL was deleted and 159 bp of M-BCR including exon b3 was duplicated, indicating either that the single-stranded cuts may span a larger distance than previously thought or that another mechanism, perhaps involving gene conversion, may be involved in this instance.
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PMID:Characterization of genomic BCR-ABL breakpoints in chronic myeloid leukaemia by PCR. 778 76

We report cases with a variant BCR/ABL mRNA expression lacking ABL exon a2 sequences. Two of these cases showed major breakpoint cluster region (BCR) exon 3 (b3) and ABL exon 3 (a3) junction (b3/a3), while the other case showed minor BCR exon 1 (e1) and a3 junction (e1/a3). One of the two cases with b3/a3 junction and the case with e1/a3 junction were diagnosed as acute lymphoblastic leukemia, and the remaining case with b3/a3 junction was chronic myeloid leukemia. Two of these cases, however, were found to have a breakpoint in the ABL gene outside of the intron between exons a2 and a3, probably 5' upstream of exon a2, suggesting that the BCR exon was spliced to ABL exon a3. These findings differ from those previously reported, in which the breakpoints in the ABL gene were between exons a2 and a3, and indicate a novel mechanism for the deletion of ABL exon a2 sequences in the formation of a variant BCR/ABL fusion transcript. The significance of the finding that a part of the SH3 region of ABL protein is missing in some Philadelphia chromosome-positive leukemias is discussed in reference to the cases reported previously.
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PMID:Heterogeneity of the breakpoint in the ABL gene in cases with BCR/ABL transcript lacking ABL exon a2. 793 65

Cytogenetic analysis of a pediatric patient with T-cell acute lymphoblastic leukemia (T-ALL) revealed a mosaic karyotype, 47,XX,+17,t(11;14)(p13;q11)/47,XX,+17,t(9;22)(q34;q11),t(11;14) (p13;q11). DNA blot analysis was used to examine the break-point within the BCR gene on chromosome 22 and showed that the breakpoint occurred within the 20-kb minor breakpoint cluster region (m-bcr) located within the first intron of the BCR gene. Immunoprecipitation analysis demonstrated that the leukemic cells expressed the P185 BCR-ABL protein tyrosine kinase. P185 BCR-ABL has previously been shown to be expressed in most cases of Ph+ acute leukemia of myeloid and B-progenitor origin. Here, we demonstrate for the first time that P185 can also be expressed in the T-cell lineage. DNA blot hybridization was also used to characterize the t(11;14) translocation. This showed rearrangement on chromosome 11 within the T-ALLbcr region, upstream of the RBTN-2 gene. Polymerase chain reaction revealed the presence of RBTN-2 transcripts in the leukemic cells. Finally, comparison of the T-ALLbcr, BCR-ABL, IGH, TCR beta and gamma gene rearrangements in leukemic cells obtained at the time of diagnosis and at first relapse showed that relapse occurred in a leukemic clone indistinguishable from the major Ph+ clone involved at diagnosis. Together, these data support a multistep pathogenesis in which the Philadelphia (Ph) chromosome translocation appeared subsequent to the +17 and t(11;14) and imparted a growth advantage over the Ph-negative cells that carried these abnormalities.
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PMID:Simultaneous expression of RBTN-2 and BCR-ABL oncogenes in a T-ALL with a t(11;14)(p13;q11) and a late-appearing Philadelphia chromosome. 803 4


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