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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)
We have tested whether peripheral blood mononuclear cells (PBMNCs) from interferon (IFN)-treated patients may lose residual BCR-
ABL
sequence-positive progenitor cells when long-term cultured for 35 days on allogeneic stromal cells. IFN-treated patients have low white blood cell counts and a fair number of BCR-
ABL
-negative colony-forming cells in the peripheral blood. Particularly, IFN responders show increased numbers of normal hematopoietic cells. We have quantitatively analyzed progenitor cells in PBMNCs of IFN-treated patients by combining the clonogenic assay in semisolid medium with interphase fluorescent in situ hybridization (FISH). Thus, the identification is possible of the BCR-
ABL
status of colony-forming progenitor cells. In IFN-treated patients, the number of BCR-
ABL
-positive CFCs is considerably decreased and BCR-
ABL
-negative CFCs appear in the peripheral blood. We could show that after LTC for 35 days of the same PBMNCs on irradiated allogeneic normal stromal cells residual BCR-
ABL
sequence-positive CFCs were still present. In some cases the relative number of BCR-
ABL
sequence-positive CFCs was found to be increased after LTC. A minor proportion of blood samples from IFN-treated patients did not give rise to CFCs after LTC on allogeneic stromal cells (three of 10 patients). Inter- and intraindividual variations can be found with regard to loss or gain of BCR-
ABL
sequence-positive colonies after LTC. We conclude that early
CML
progenitor cells persist in the peripheral blood of IFN-treated patients and that a certain proportion may survive long-term culture.
...
PMID:Does long-term culture favor normal clonogenic cells from interferon-treated patients with chronic myelogenous leukemia? 1023 67
Quantitative competitive RT-PCR techniques have been developed to detect BCR-ABL fusion transcripts in
CML
but they are hardly reproducible. In this work, we have developed BCR-
ABL
quantification by real time RT-PCR using the ABI PRISM 7700 (Perkin Elmer), a new technique which allows simple and rapid quantification of a target sequence during the extension phase of PCR amplifications. A fluorogenic probe labeled with both a reporter dye at the 5' end and a quencher-dye at the 3' end hybridizes to the target sequence on the third exon of the
ABL
gene. The exonuclease activity of the Taq DNA polymerase cleaves the probe and releases the reporter dye, resulting in an increase in the fluorescence signal. The absolute copy number of the target sequence (BCR-
ABL
) or a control gene (
ABL
) in an unknown sample can then be calculated using a calibration curve prepared from a set of BCR-
ABL
RNA standards, and results are expressed as a BCR-
ABL
/
ABL
ratio. In our hands, the sensitivity of a serial dilution of total RNA from a positive cell line (K562) in a negative cell line (HL60) was 10(-4). Fifteen
CML
patients in cytogenetic CR, including 11 allografted patients, two autografted patients and two patients treated by IFN were studied sequentially by this new real time quantitative RT-PCR technique in parallel with conventional qualitative two round nested RT-PCR. The two autografted patients showed high BCR-
ABL
/
ABL
ratio in all samples. The two patients treated by IFN showed a progressive decrease in the ratio. In the 11 allografted patients, four were sequentially studied 2 years or more after allo-BMT, and all ratios were below 10(-4). The four patients remained in clinical and cytogenetic CR. The seven other allografted patients were studied immediately after the procedure. Three of them showed a progressive decrease in the BCR-
ABL
/
ABL
ratio which reached 10(-4) 7 months after allo-BMT. The three patients remained in hematologic and cytogenetic CR. The remaining four allografted patients had progressive increase of BCR-
ABL
ratio; three developed cytogenetic relapse 9, 11, 28 months after allo-BMT, and the last patient remained in cytogenetic CR in the bone marrow but developed granulocytic sarcoma. Results of real-time quantitative RT-PCR were in agreement with those of qualitative two round nested PCR. However, evolution changes in the results of real-time quantitative RT-PCR often preceded those of the conventional technique: a decrease of the BCR-
ABL
/
ABL
ratio preceded progression from first round to second round positivity and then negativity with the classical technique; conversely, an increase in the ratio preceded evolution with the classical technique. Thus, real-time quantitative RT-PCR may show better correlation with clinical and cytogenetic evolution than conventional qualitative techniques and may help in making early therapeutic decisions in
CML
, especially after molecular relapse.
...
PMID:Detection of BCR-ABL transcripts in chronic myeloid leukemia (CML) using a 'real time' quantitative RT-PCR assay. 1036 Mar 86
Antisense oligodeoxyribonucleotides (ODN) targeted against the breakpoint in BCR-
ABL
mRNA will specifically decrease BCR-
ABL
mRNA, provided cells are first permeabilised with streptolysin-O (SL-O). We used 18-mer chimeric methylphosphonodiester: phosphodiester linked (4-9-4) ODN complementary to 9 bases either side of the BCR-
ABL
junction to purge harvests ex vivo in three
CML
patients who remained completely Ph positive after multiple chemotherapy courses. After CD34+ cell selection and SL-O permeabilisation, harvests were purged with 20 microM ODN. After purging, all individual CFU-GM colonies grown from the two b3a2 breakpoint cases remained positive for BCR-
ABL
mRNA. In contrast, all 24 colonies grown from the b2a2 breakpoint case were BCR-
ABL
mRNA negative. Patients were conditioned with busulphan 16 mg/kg. The initial post-transplant course was uneventful, although the time to return to 0.5 x 10(9)/l neutrophils was slow at 25-51 days. Both chronic phase patients remain in haematological remission at +724 and +610 days, although each has cytogenetic evidence of relapse. The b2a2 accelerated phase patient died of myeloid blast transformation at day +91. The present SL-O-facilitated ODN purging strategy appears to be without significant toxicity, and offers considerable improvements in ODN delivery to the cytosol.
...
PMID:Clinical use of streptolysin-O to facilitate antisense oligodeoxyribonucleotide delivery for purging autografts in chronic myeloid leukaemia. 1041 20
The expression of the BCR-ABL fusion oncoprotein in primitive hematopoietic cells results in chronic myeloid leukemia. Over the past decade studies of several in vitro and in vivo cell systems revealed multiple signal transduction pathways activated by BCR-
ABL
. However, the precise function of BCR-
ABL
in the pathogenesis of
CML
is still unclear. The goal of this review is to synthesize data on intracellular signaling in the context of the diverse murine assay systems employed. We emphasize the importance of in vivo assays and assays using primary cells in understanding the biology of
CML
and the molecular mechanisms by which BCR-
ABL
exerts its effects.
...
PMID:Growth factor independence and BCR/ABL transformation: promise and pitfalls of murine model systems and assays. 1045 Jul 47
Patients with
CML
post allogeneic BMT or during treatment with Interferon were monitored in bone marrow and peripheral blood for BCR-
ABL
transcripts by RT-PCR and in the majority of cases also by Southern blotting. Bone marrow and peripheral blood samples were obtained simultaneously and tested by RT-PCR with the objective to determine the usefulness to follow
CML
patients by testing peripheral blood rather than bone marrow samples. For the purpose of this study we have considered the test results obtained from bone marrow samples as the standard. A total of 111
CML
patients were examined who underwent either an allogeneic BMT (n=91) or were treated with Interferon (n=20) amounting to a total of 163 assessments for BCR-
ABL
. Concordance of results was observed in 153 samples (93.9%). 10 samples showed discordance. Seven of these were subjected to repeat testing by RT-PCR. The previously obtained discordant results were confirmed. The sensitivity of peripheral blood assays was calculated to be 96.2% with a specificity of 89.5%. RT-PCR results restricted to Southern blot negative patients showed concordance of bone marrow and peripheral blood in 91.1% of tested samples with a sensitivity of 92.7% and a specificity of 88.6%. The subset of patients in which Southern blot testing was not available showed concordance at a similar level. Complete concordance was seen in all patients that were found to be positive by Southern blotting. We conclude from this study that peripheral blood testing for BCR-
ABL
transcripts by RT-PCR is a test with high sensitivity and specificity and may potentially replace bone marrow testing. This approach will probably result in a high level of acceptance by patients and may permit more frequent monitoring.
...
PMID:Comparative testing of peripheral blood and bone marrow for BCR-ABL transcripts in patients post allogeneic bone marrow transplantation and during interferon treatment for chronic myeloid leukemia. 1049 72
Chronic myelogenous leukemia is characterized by an abnormal 22nd chromosome known as a Philadelphia chromosome, which can be detected in 95% of patients with
CML
. Molecular equivalent of this aberration is a BCR-
ABL
translocation resulting in chimeric gene formation. A BCR-
ABL
chimeric gene plays a key role in the hematopoietic cells proliferation regulation. RT-PCR can be used in diagnosis of
CML
, to detect chimeric BCR-
ABL
gene, and to reveal the type of translocation what could have prognostic importance, and in monitoring of minimal residual disease, confirming the eradication of pathological cells clone after treatment and identifying the group of patients with best prognosis and best overall survival. RT-PCR in monitoring of minimal residual disease after allo- or autologous hemopoietic cells transplantation can early reveal relapse of the disease. Detection of molecular relapse is an important prognostic factor and may implicate induction of treatment which should prevent haematological relapse of the disease.
...
PMID:[Molecular basis of chronic myelogenous leukemia and significance of diagnostic methods based on BCR-ABL gene amplification]. 1049 84
Chronic myelogenous leukemia in more than 90% of patients is associated with the abnormal Philadelphia chromosome, which results in aberrant BCR-
ABL
chimeric gene expression. The mean overall survival on standard chemotherapy (which is not curative) ranges between 54-72 months. Selected patients with
CML
can be cured by allogeneic hemopoietic stem cell transplantation. Only 30% of patients has an optimal HLA-identical sibling donor. It is possible to find well-matched unrelated donor for another 20-30% of patients, however matched-unrelated donor transplantation is still associated with relative high risk of complications and cannot be used in elderly patients. Interferon alpha treatment in monotherapy or in combination with ARA-C can induce a cytogenetical and molecular remission in selected group of patients, which benefits with significantly prolonged survival. Nevertheless the cost of this treatment is high and long period of therapy is required to assess its efficacy. In patients lacking matched related or unrelated donors for allogeneic transplantation, autologous stem cell transplantation could be the alternative method of treatment. Discussed in the paper method of mobilization and transplantation of Philadelphia-negative peripheral-blood progenitor cells collected during early phase of bone marrow regeneration after "mobilizing" chemotherapy (mini-ICE) enables to achieve a complete or major cytogenetical response in about 77% of patients. There is only minimal morbidity and no transplant-related mortality. This procedure and the post-transplant immunotherapy (IFN alpha, interleukin-2) can considerably suppress the pathological clone and significantly prolong the overall survival in
CML
patients not eligible for allogeneic transplantation.
...
PMID:[Autologous hemopoietic stem cell transplantation in treatment of chronic myelogenous leukemia]. 1049 85
CML
is the myeloproliferative disorder connected with the specific chromosome translocation (9;22) and occurrence of the fusion gene/protein BCR-
ABL
. BCR-
ABL
protein is believed to inhibit apoptosis and to cause drug resistance. We investigated the correlation of two different forms of BCR-
ABL
mRNA in 94 pts with their overall survival. It was found that b2a2 (but not b2a3) mRNA expression correlates with longer survival of patients treated with chemotherapy. We did not find an influence of different types of BCR/ABL mRNA on the survival of pts treated with interferon-alpha. FAS/APO-1 antigen was expressed by the cells of 34% of the pts in
CML
blast crisis (BC) and directly correlated with the the expression of CD34, CD13 and CD14 differentiation antigens. FAS/APO-1 non-expression correlated with higher rate of remissions in BC. We investigated P-glyco-protein (Pgp) expression and functional activity in 40 BC
CML
pts. 2-fold shorter survival was found in the pts with Pgp expression. Pgp expression strongly correlated with CD13 antigen. Consecutive studies of pts in BC
CML
show that Pgp expressing cells often do not multiply in the course of BC
CML
. We postulate that Pgp may be regarded as differentiation marker of the cells and the unfavorable prognostic factor in BC
CML
.
...
PMID:Studies of some mechanisms of drug resistance in chronic myeloid leukemia (CML). 1050 Aug 25
We report a chronic myeloid leukemia patient without evidence of a Philadelphia (Ph) chromosome in whom RT-PCR analysis performed in blast crisis demonstrated the existence of both common b3a2 and b2a2 BCR/ABL fusion transcripts. In situ hybridization studies with BCR- and
ABL
-specific probes showed location of the BCR/ABL fusion gene on chromosome 9, band q34, instead of at chromosome 22q11, and that it resulted from an insertion of the 5' side of BCR within the
ABL
gene on chromosome 9. The vast majority of cells showed a BCR/ABL fusion gene on both chromosomes 9, which is equivalent to a double Ph chromosome, thus reinforcing the notion that the critical event in
CML
is the formation of a functional BCR/ABL fusion gene.
...
PMID:Insertion of the 5' part of BCR within the ABL gene at 9q34 in a Philadelphia-negative chronic myeloid leukemia. 1052 30
We sought to establish a rapid and reliable RT-PCR approach for detection and quantification of BCR-ABL fusion transcripts using the LightCycler technology. This device combines rapid thermocycling with online detection of PCR product formation and is based on the fluorescence resonance energy transfer (FRET) between two adjacent hybridization probes carrying donor and acceptor fluorophores. A pair of probes was designed that was complementary to
ABL
exon 3, thus enabling detection of all known BCR-
ABL
variants and also normal
ABL
as an internal control. Conditions were established to amplify less than 10 target molecules/reaction and to detect one
CML
cell in 105 cells from healthy donors. To determine the utility of the assay, we quantified BCR-
ABL
and
ABL
transcripts in 254 samples (222 peripheral blood, 32 bone marrow) from 120 patients with
CML
after therapy with IFN-alpha (n = 219), allogeneic BMT (n = 17), chemotherapy (n = 11), or at diagnosis (n = 7). The level of residual disease in the 245 BCR-
ABL
positive specimens was expressed as the ratio of BCR-
ABL
/
ABL
. This ratio was compared to results obtained by three established methods from contemporaneous specimens. A highly significant correlation was seen between the BCR-
ABL
/
ABL
ratios determined by the LightCycler and (1) the BCR-
ABL
/
ABL
ratios obtained by nested competitive RT-PCR (n = 201, r = 0.90, P < 0. 0001); (2) the proportion of Philadelphia chromosome positive metaphases determined by cytogenetics (n = 81, P < 0.0001); and (3) the BCR ratio determined by Southern blot analysis (n = 122, P < 0. 0001). We conclude that real-time PCR with hybridization probes is a reliable and sensitive method to monitor
CML
patients after therapy. The major advantages of the methodology are (1) amplification and product analysis are performed in the same reaction vessel, avoiding the risk of contamination; (2) the results are standardized by the quantification of housekeeping genes; and (3) the complete PCR analysis takes less than 60 min.
...
PMID:Accurate and rapid analysis of residual disease in patients with CML using specific fluorescent hybridization probes for real time quantitative RT-PCR. 1055 58
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