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Query: EC:2.7.10.2 (
focal adhesion kinase
)
44,029
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
The Philadelphia chromosome defines chronic myeloid leukemia, and is mostly based on a translocation t(9;22) with a typical BCR-
ABL
rearrangement which also occurs in so called atypical translocations. The transformation of chronic myeloid leukemia is associated with clonal evolution in 80% of cases. The appearance of an isochromosome 17q unequivocally heralds the onset of a myeloid type of
blast crisis
. Treatment of Ph-positive CML has still to be considered palliative except for allogeneic bone marrow transplantation. The Philadelphia chromosome is also found in about 20% of patients with acute lymphoblastic leukemia and in about 2% of patients with nonlymphoblastic leukemia. It is associated with a poor prognosis. Molecular and cytogenetic findings help differentiating between de novo acute leukemia and
blast crisis
of chronic myeloid leukemia.
...
PMID:[Cytogenetic and clinical features of Philadelphia chromosome positive leukemias]. 170 14
The first consistent karyotypic abnormality found to be associated with neoplastic disease was the Philadelphia (Ph) chromosome (Nowell & Hungerford, 1960). Furthermore, the best-studied example of translocation-mediated gene activation occurs in leukaemia patients bearing this abnormality (reviewed by Kurzrock et al, 1988). In these individuals, the Ph translocation (t(9;22)(q34;q11)) results in transposition of the
ABL
proto-oncogene from chromosome 9q34 to 22q11, where it is fused with part of the BCR gene. It is now known that as a result of the Ph translocation, p160BCR and p145ABL (the normal BCR and
ABL
gene products) are replaced by p210BCR-
ABL
. This aberrant protein constitutes the molecular fingerprint of CML. The enhanced tyrosine phosphokinase enzymatic activity (a property possessed by some growth factor receptors and transformation-inducing oncogenes) of p210BCR-
ABL
implicates a direct role for this molecule in the pathogenesis of CML. Because the Ph translocation is present in the early chronic phase, the union of the BCR and
ABL
genes is probably involved in the initiation of the leukaemic process. The secondary molecular forces driving progression of CML to
blast crisis
are however unknown, and may differ from patient to patient. Approximately 10% of CML patients lack a Ph chromosome. One-half of these individuals have bcr rearrangement and express p210BCR-
ABL
. Ph+ and Ph- bcr+ (p210+) CML are identical and should be treated the same. Molecular follow-up of diploid bcr+ CML patients is essential for detection of persistent malignancy after therapy. The presence of a specific marker--the BCR-
ABL
message--permits the development of new diagnostic approaches for CML. For instance, detection of a BCR-
ABL
message with the use of the highly sensitive polymerase chain reaction, a technique capable of detecting up to one leukaemia cell amongst one million normal cells, yields important information about minimal residual disease. Finally, the use of therapy directed against the BCR-
ABL
product may be a worthwhile strategy which deserves investigation, and may prompt a new era of tumour-specific treatment.
...
PMID:The molecular pathology of chronic myelogenous leukaemia. 193 6
The BCR gene, on chromosome 22, is involved in the Philadelphia (Ph1) chromosome which is a characteristic cytogenetic marker of chronic myeloid leukaemia (CML). Breakpoints in CML occur within the M-bcr region (5.8 kb) which encompasses exons 12-15 (b1-b4), and the M-bcr can be conveniently divided into five zones by restriction mapping. One of these zones (3) contains exon b3 which can be either present or absent from the hybrid mRNA, even if it is present in the chimaeric gene. We have mapped the breakpoints around BCR exon b3 and related this to the type of RNA splice site expressed, in CML patients at diagnosis. Breakpoints within zone 3 were restriction mapped to one of six sub-zones and the site related to the type of RNA splice site. Two clusters of breakpoints within zone 3 were observed. One cluster was located around exon b3 and often resulted in deletion of exon b3 from the chimaeric gene. The majority of this cluster expressed b2-a2 spliced RNA, usually as a consequence of a deletion removing exon b3. The second cluster occurred within two sub-zones that spanned an Alu sequence, and 90% of this cluster exhibited b3-a2 spliced RNA. Furthermore, a greater number of patients had entered
blast crisis
if the RNA contained BCR exon b3 (8 of 10 patients), compared to those with b2-a2 spliced RNA (3 of 12 patients). The high degree of heterogeneity in the site of the breakpoint within zone 3 of the M-bcr, combined with the type of BCR-
ABL
hybrid mRNA expressed, further implicates BCR exon b3 in the pathogenesis of CML.
...
PMID:Mapping of breakpoints, and relationship to BCR-ABL RNA expression, in Philadelphia-chromosome-positive chronic myeloid leukaemia patients with a breakpoint around exon 14 (b3) of the BCR gene. 196 Oct 34
The Philadelphia translocation in chronic myelogenous leukemia (CML) results in the production of a 210 kD BCR-
ABL
protein. In contrast, in 50% of Philadelphia-positive acute leukemias, the translocation results in the production of a 190 kD BCR-
ABL
protein. To investigate the hypothesis that the production of P190 may be associated with the progression from chronic phase to
blast crisis
in CML, we used polymerase chain reaction to analyze blood from 37 patients with accelerated phase/
blast crisis
CML for the transcripts coding for the P210BCR-
ABL
and P190BCR-
ABL
. The mRNA encoding for P210 was detected in all patients. In three patients, mRNA encoding both P210 and P190 was present. In two of these three patients, samples were available from the time of initial diagnosis. Analysis of these samples did not reveal any transcripts for P190. We conclude that in some patients the appearance of P190BCR-
ABL
may correlate with transformation to a more aggressive, terminal phase of CML.
...
PMID:Appearance of acute leukemia-associated P190BCR-ABL in chronic myelogenous leukemia may correlate with disease progression. 201 78
More than 95% of patients with chronic myelogenous leukemia (CML) contain an abnormal chromosome termed the Philadelphia chromosome (Ph1). Ph1 and the resulting BCR-
ABL
fused genes are markers for this type of leukemia. The product of the fused BCR-
ABL
genes is a protein of about 2000 amino acids termed P210 BCR-
ABL
. Although the BCR-
ABL
protein can be routinely detected in blood cells from
blast crisis
CML patients by assaying for its activated tyrosine kinase activity, detection of P210 BCR-
ABL
in early stage CML patients (chronic phase) has not yet been possible (S. A. Maxwell et al., Cancer Res., 47: 1731, 1987). A procedure involving Western blotting with an anti-
ABL
monoclonal antibody was developed that allows detection of P210 BCR-
ABL
and P145
ABL
in cells from chronic phase and
blast crisis
CML patients, but as expected only P145
ABL
was found in normal white blood cells. Most chronic phase patients also contained one to two
ABL
proteins with a molecular weight of about 190,000. Interestingly, the ratio of BCR-
ABL
to
ABL
proteins increased in four
blast crisis
patients compared to 18 chronic phase patients. Also, one chronic phase patient analyzed on three separate occasions lacked P210 BCR-
ABL
and exhibited only the Mr 190,000 form. This assay should also be useful in other leukemias that express altered forms of the
ABL
protein.
...
PMID:Detection of BCR-ABL proteins in blood cells of benign phase chronic myelogenous leukemia patients. 203 43
Cytogenetic and molecular aspects of Ph-positive leukemia are described in comparison with those of Ph-positive CML. Chromosomal characteristics of Ph+AL are; 1) mixture of a normal karyotype at diagnosis, 2) frequent combination with +Ph, +21, +6, +8, or -7, 3) recovery of a normal karyotype at remission. Additional chromosome changes at myeloid
blast crisis
(BC) of CML are characterized by +Ph, i(17q), +8, or +19. Meanwhile, lymphoid BC exhibits +Ph, +21, but not i(17q) or +19. There seems no cytogenetic difference between Ph+AL and lymphoid BC of CML, but i(17q) may be specific for CML BC. Eight patients with Ph+AL were studied with pulsed-field gel electrophoresis (PFGE) to examine the break site within
ABL
and BCR genes. One case had a M-BCR rearrangement and the remainder a rearrangement upstream of M-BCR. Minor-BCR rearrangement occurs seldom in CML but is detected in approximately a half of the reported cases of Ph+AL.
ABL
was rearranged within 1st or 2nd intron in all 8 cases.
ABL
breakpoints appear randomly distributed between exons 1b and 2 in both Ph+AL and CML.
...
PMID:[Cytogenetic and molecular aspects of Ph-positive leukemia]. 206 72
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.
...
PMID:Molecular pathology of chronic myelogenous leukemia. 224 53
A patient who was diagnosed with chronic myeloid leukemia remained in chronic phase for 14 years before progressing into a lymphoid
blast crisis
in 1983. The acute phase was successfully treated, and the patient has remained in an indolent chronic phase to date. Cytogenetic and molecular analysis during this second chronic phase confirm the presence of the Philadelphia chromosome and its transcribed BCR-
ABL
mRNA. The breakpoint within M-bcr occurred in the 3' portion of the region and expressed a hybrid joining the b3 exon of BCR to the a2 exon of
ABL
.
...
PMID:Molecular analysis of a CML patient with a long duration of chronic phase before and after lymphoid blast crisis. 235 47
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.
...
PMID:Analysis of BCR-ABL mRNA in chronic myelogenous leukemia patients and identification of a new BCR-related sequence in human DNA. 248 58
The monoclonal antibody (MoAb) Bsp-1 was used to purify basophilic cells from leukemic blood of five patients with Philadelphia chromosome (Ph') positive chronic myeloid leukemia (CML) and two patients with acute myeloid leukemia (AML) characterized by the chromosomal translocation t(6;9)(p23;q34). When cultured, Bsp-1 positive cells from all CML and AML patients showed the same clonal karyotype changes observed in diagnostic buffy coat preparations, indicating that the basophilic cells were of leukemic origin. In contrast, T lymphocytes from four of five CML patients cultured in the presence of interleukin-2 (IL-2) showed a normal karyotype and were therefore not derived from the leukemic clone. Bsp-1 staining correlated with toluidine blue-positive basophils in chronic phase CML and with toluidine blue-negative blast cells expressing an immature myeloid phenotype in
blast crisis
CML and AML. Chromosome in situ hybridization showed that the
ABL
oncogene was translocated from chromosome 9 to chromosome 22 in the CML patients but remained on chromosome 9 in the AML patients. These results indicate that the breakpoint at 9q34 in CML is 5' of
ABL
, whereas the breakpoint at 9q34 in AML is 3' of
ABL
. Field inversion gel electrophoresis showed that the 9q34 breakpoint was not within 200 kb 3' of
ABL
in one of the AML patients, nor was there any rearrangement of the PIM oncogene locus at 6p21.
...
PMID:Basophils (Bsp-1+) derive from the leukemic clone in human myeloid leukemias involving the chromosome breakpoint 9q34. 264 88
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