Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Pivot Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Target Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Query: EC:2.7.10.2 (
focal adhesion kinase
)
44,029
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
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
Chronic myelogenous leukemia (CML) is characterized by the presence of the Philadelphia (Ph) chromosome in clonally derived hematopoietic precursors and their progeny. The Ph chromosome arises from a translocation that deregulates the c-ABL protein tyrosine kinase, giving it transforming potential and increased kinase activity. We observed a unique 39-kD tyrosine phosphoprotein (pp39), previously reported in blastic CML cell lines, in neutrophils from 50 cases of
chronic phase CML
. This protein was prominently and constitutively tyrosine-phosphorylated in CML neutrophils and was not phosphorylated in normal neutrophils. Stimulation of normal neutrophils with cytokines and agonists did not induce tyrosine phosphorylation of proteins migrating in the region of pp39, and the phosphorylation state of pp39 in CML neutrophils was not affected by kinase inhibitors known to downregulate the
ABL
kinase. The pp39 was not phosphorylated in hematopoietic cells from healthy donors or from patients with Ph chromosome-negative myeloproliferative disorders. Using micro amino acid sequencing of purified preparations of pp39, we identified pp39 as CRKL protein, which is consistent with recent immunologic studies in the blastic K562 cell line. Immunoblotting with anti-CRKL antibodies showed the presence of CRKL protein in CML cells and cell lines as well as in antiphosphotyrosine immunoprecipitates from CML cells. Our results suggest that pp39 CRKL in CML neutrophils may be stably tyrosine-phosphorylated by the BCR/ABL kinase at an early stage of myeloid differentiation when the
ABL
kinase is active. CRK, CRKL, and other SH2 (
SRC
homology domain)/SH3-containing proteins function as adaptor molecules in nonreceptor tyrosine kinase signalling pathways. Although the CRKL protein is present in normal neutrophils, it is not tyrosine-phosphorylated, and the inability to induce such phosphorylation in normal neutrophils suggests a special role of this phosphoprotein in the pathogenesis of CML. Constitutive phosphorylation of CRKL is unique to CML, indicating that it may be a useful target for therapeutic intervention.
...
PMID:Identification of CRKL as the constitutively phosphorylated 39-kD tyrosine phosphoprotein in chronic myelogenous leukemia cells. 752 58
There is remarkable recent progress in our understanding of the biology of chronic myelogenous leukemia (CML). First, the BCR/ABL rearrangement was identified as the molecular basis of the disease. Second, animal models support the notion that the BCR/ABL gene product causes a syndrome similar to CML. Third, recent advances in understanding the functions of the normal
ABL
protein have given clues to the mechanism(s) of
ABL
-induced leukemias and approaches to blocking this process. Extrapolating these findings to humans seems reasonable. The challenge now is to determine how the BCR/ABL gene product causes
chronic phase CML
. Also unresolved is whether BCR/ABL also plays a role in the acute phase of the disease. Finally, the relationship between the two common forms of BCR/ABL, the P190 and P210 configurations, and different disease phenotypes, like CML and Philadelphia (Ph1)-chromosome positive acute lymphoblastic leukemia (ALL), needs to be clarified. There is also substantial progress in treating CML. Bone marrow transplants have emerged as the preferred therapy. These result in long-term leukemia-free survival in more than one-half of appropriately selected subjects. How transplants cure CML is complex and controversial. Some data suggest high-dose treatment is the dominant factor whereas other data implicate antileukemia effects of the immune system. Interferon treatment has also proven effective in CML. Whether it prolongs survival of persons with CML remains to be determined, as does its mechanism of action. Certainly the most important and difficult challenge in CML therapy is determining how to use knowledge about the causes CML to treat the disease. These and other issues in the biology and therapy of CML were the subject of a recent meeting of basic and clinical scientists. The meeting, third in a series begun in 1987, was held on Martha's Vineyard, Cape Cod, Massachusetts, USA from 4-7 April, 1992. Four major topics were considered in five sessions: molecular biology, cell biology, Ph1-chromosome positive ALL, and therapy of CML. This report summarizes meeting highlights.
...
PMID:Chronic myelogenous leukemia: biology and therapy. 846 45
One hundred and forty-three patients with p210 BCR-
ABL
-positive leukemia were studied for coexpression of p190 BCR-
ABL
mRNA. p190 mRNA was detected in 14 of 16 (88%) patients with chronic-phase chronic myeloid leukemia (CML) at diagnosis, in 10 of 10 (100%) CML patients in blast crisis, in 75 of 107 (70%) CML patients receiving interferon-alpha (IFN-alpha), and 10 of 10 (100%) patients with p210 BCR-
ABL
-positive acute lymphoblastic leukemia (ALL). Neither p210 nor p190 BCR-
ABL
transcripts were detected in normal healthy adults (n = 20). The numbers of p190 transcripts determined by competitive PCR in patients with CML were low compared with the numbers of p210 transcripts. The median numbers of p210 and p190 transcripts per unit volume of cDNA in positive samples were 1.0 x 10(5) (range, 15 to 1.4 x 10(6)) and 10 (range, 10 to 2.9 x 10(3)), respectively. The numbers of p190 and p210 transcripts were significantly correlated in individual samples (r = .65, P < .001). The median number of p210 BCR-
ABL
transcripts was significantly lower in samples negative for p190 BCR-
ABL
transcripts than in samples in which p190 BCR-
ABL
transcripts were identified (3.1 x 10(3)[n = 73] v 1.0 x 10(5)[n = 115]; P < .0001). The median ratio of p190 to p210 BCR-
ABL
mRNA was not significantly different between
chronic phase CML
(1.9 x 10(-4)) and CML in blast crisis (1.7 x 10(-4)). The median ratio in p210 ALL was also low (1.9 x 10(-3)) but significantly higher than that of CML. We conclude that pl90 BCR-
ABL
transcripts are frequently present at a low level in p210 BCR-
ABL
-positive leukemias. p190 mRNA may arise through alternative or missplicing and its presence is probably of no pathogenetic significance.
...
PMID:p190 BCR-ABL mRNA is expressed at low levels in p210-positive chronic myeloid and acute lymphoblastic leukemias. 865 35
Chronic myelogenous leukemia (CML) can sometimes present in lymphoid blast phase (L-BP), and can be difficult to distinguish from Philadelphia chromosome-positive (Ph+) acute lymphoblastic leukemia (ALL). Some have suggested that the determination of cell lineages involved by the Ph chromosome may be used for distinguishing CML presenting in L-BP (presumably multilineage disease) from Ph+ ALL (presumably lymphoid-restricted), although others have suggested the term 'stem cell ALL' for the multilineage process. Because it has been difficult to perform lineage studies of the Ph chromosome, we investigated the use of fluorescence in situ hybridization (FISH) with probes for BCR (on chromosome 22) and
ABL
(on chromosome 9) to study lineage involvement in Ph+ lymphoblastic malignancies. We analyzed routine blood and marrow specimens from eight patients who presented with Ph+ lymphoblastic leukemia and found that FISH recognized the 9;22 translocation, distinguished between the two common molecular variants, and readily identified multilineage vs lymphoblast-restricted disease. In our series, four patients had multilineage and four had lymphoblast-restricted disease. Multilineage disease was associated with morphologic features of CML at diagnosis and/or reversion to
chronic phase CML
after treatment leading us to consider it as CML presenting in L-BP. Patients with lymphoid-restricted disease lacked such findings. The survival of three of our four patients with multilineage disease was prolonged, at 25, 28+, and 126+ months, and when data from our entire series are added to those of 18 previously reported cases that were studied for lineage involvement (reviewed in Leukemia 1993; 7: 147), the difference in overall survival between patients with multilineage and lymphoblast-restricted disease is significant (median overall survival of 47 months vs 8 months, respectively; P=0.013, log rank). Our findings illustrate that FISH analysis can be used to recognize lineage involvement in patients presenting with Ph+ lymphoblastic malignancies, and they provide further support to the notion that multilineage and lymphoblast-restricted disease are distinct clinically as well as biologically.
...
PMID:Lineage involvement by BCR/ABL in Ph+ lymphoblastic leukemias: chronic myelogenous leukemia presenting in lymphoid blast vs Ph+ acute lymphoblastic leukemia. 865 74
The LH2 gene encodes a putative transcription factor containing two N-terminal LIM and one C-terminal HOX domains. The LH2 locus was mapped to 9q33-34.1, centromeric to the
ABL
gene. In a recent report, it was suggested that high levels of LH2 expression are consistently observed in chronic myeloid leukemia (CML) patients, whereas no transcription is detected in normal individuals. This led to the hypothesis that aberrant expression of LH2 may represent an additional mechanism for malignant cell proliferation in CML. We have studied the expression of LH2 in leucocytes from patients with CML or with other chronic myeloproliferative disorders (CMD), and from normal individuals, using an optimised reverse-transcription and polymerase chain reaction (PCR) technique. Twenty-seven out of 29 cDNA samples from normal individuals (93%), 49 out of 51 samples from CML patients (96%) and 20 out of 20 from Philadelphia chromosome-negative CMD showed evidence of LH2 expression. Similarly, LH2 transcription was also detected in leucocytes from CML patients in complete cytogenetic remission after treatment with interferon-alpha. Furthermore, all 36 EBV-induced lymphoblastoid cell lines established from six
chronic phase CML
patients showed unequivocal LH2 expression, regardless of the BCR-
ABL
status of the line (9 BCR-
ABL
positive, 27 BCR-
ABL
negative). We conclude that LH2 expression is not confined to CML cells, and that the t(9;22)(q34;qll) does not promote 'de novo' transcriptional activation of this gene.
...
PMID:Expression of the LH2 gene in chronic myeloid leukaemia cells. 868 90
Chronic myeloid leukaemia (CML) can be treated successfully with allogeneic bone marrow transplantation (BMT) leading to long-term disease-free survival. Leukemia relapse, however, remains a significant clinical problem. Relapse following BMT presumably results from the expansion of small numbers of recipient leukaemic cells which have survived the conditioning therapy. In order to define patients who are at a high risk of leukaemia relapse, a variety of techniques have been employed to detect persistence of host haemopoiesis (mixed chimaerism, MC) or residual leukaemia (minimal residual disease, MRD). However, the precise relationship between the detection of MC and MRD post-BMT is unknown. We have investigated chimaerism and MRD status in 22 patients who were in clinical and haematological remission post-allogeneic BMT for
chronic phase CML
. Chimaerism was assessed using short tandem repeat PCR (STR-PCR) while BCR-
ABL
mRNA detection using reverse transcriptase polymerase chain reaction (RT-PCR) was performed to detect the presence of MRD. Seventeen patients received unmanipulated marrow (non-TCD) while in five patients a T cell-depleted transplant (TCD) was performed as additional GVHD prophylaxis. Chimaerism was evaluated in 18 patients (14 non-TCD, four TCD). Mixed chimaerism was an uncommon finding in recipients of unmanipulated BMT (21%) when compared to TCD BMT (100%). No evidence of MRD, as identified using the BCR-
ABL
mRNA RT-PCR assay, was detected in those patients who were donor chimaeras. Early and transient MC and MRD was detected in four patients (two non-TCD, two TCD) who have subsequently converted to a donor profile. One patient has stable low-level MC but remains MRD negative 4 years post-BMT. Late MC and MRD was observed in two patients who relapsed >6 years after TCD BMT for CML. We conclude that mixed chimaerism is a rare event in recipients of unmanipulated BMT and that donor chimaerism as detected by STR-PCR assay is consistent with disease-free survival and identifies patients with a low risk of leukaemic relapse post-BMT for CML.
...
PMID:Persistent donor chimaerism is consistent with disease-free survival following BMT for chronic myeloid leukaemia. 925 92
Philadelphia chromosome-positive (Ph+) hemopoietic cells predominate in patients with chronic myeloid leukemia (CML) in chronic phase, but some Ph presumably normal stem cells persist in most patients. Ph cells are relatively frequent, compared to mature cell populations, in primitive hemopoietic cell populations from CML patients. We have purified CD34+ cells from
chronic phase CML
blood and separated them into two fractions on the basis of adherence or non-adherence to tissue culture plastic. We also separated CD34+ CML cell populations into HLA-DR(hi) and HLA-DR(lo) fractions and CD38(hi) and CD38(lo) fractions by flow cytometry. The CD34+ cells that adhered to plastic were predominantly CD33-, CD38- and HLA(-)-DR; cells with these phenotypic properties were significantly rarer in the CD34+ non-adherent cell population (P = 0.008-0.02). Expression of p210 BCR/ABL mRNA by adherent, non-adherent, HLA-DR(hi) and HLA-DR(lo)CD34+ cell subpopulations was demonstrated by RT-PCR. Using fluorescence in situ hybridization (FISH) in conjunction with BCR and
ABL
probes we detected Ph+ and Ph- cells in both adherent and non-adherent CD34+ cell fractions of 15/15 patients studied and in the HLA-DR(lo) or CD38(lo) sorted CD34+ cell fractions. The concentration of Ph- cells in the adherent CD34+ cell fraction was three-fold higher than in the non-adherent fraction (P = 0.001). Ph- adherent cells were detected in untreated CML patients and as late as 6 years after diagnosis of CML in patients treated with hydroxyurea (HU) or interferon-alpha (IFN-alpha). We conclude that whilst appreciable numbers of Ph- primitive hemopoietic progenitors are present in the circulation in untreated patients and also in treated patients in late chronic phase, the majority of cells expressing CD34 but not CD33, CD38 or HLA-DR antigens, are part of the CML clone.
...
PMID:BCR/ABL-negative progenitors are enriched in the adherent fraction of CD34+ cells circulating in the blood of chronic phase chronic myeloid leukemia patients. 930 2
CML, characterized by the BCR/ABL gene rearrangement has been more extensively studied than any other malignancy. Over the last decade, significant progress has been made in our understanding of BCR-
ABL
-induced alterations in intracellular signaling. Unfortunately, we still only poorly understand the correlation between the clinical symptoms of
chronic phase CML
and the BCR-
ABL
oncoprotein. This is in part due to lack of a good in vivo animal model of
chronic phase CML
. In vivo and in vitro studies from the Clarkson group, recently reviewed in this journal (Leukemia 1997; 11: 1404-1428), have significantly enhanced our understanding of the pathophysiology of CML. However, further characterization of the effect of the BCR-
ABL
oncoprotein on signal molecules involved with cell differentiation, cell proliferation, cell survival and cell adhesion in primary Ph+ CML progenitors or in vivo models of CML will be needed to provide a full understanding of the pathophysiology of
chronic phase CML
.
...
PMID:Chronic myelogenous leukemia: too much or too little growth, or both? 930 92
This article reviews the biology of chronic myelogenous leukemia (CML) and its effect on the process of hematopoiesis. The relevance of the BCR-ABL fusion protein as well as murine models are also discussed. CML has been studied more extensively than any other malignancy, yet the correlation between the clinical symptoms of
chronic phase CML
and the BCR-
ABL
oncoprotein is poorly understood. Insights from recent efforts both to develop a good in vivo animal model and to characterize the effect of the BCR-
ABL
oncoprotein on relevant signal molecules may lead to a better understanding of the pathophysiology of
chronic phase CML
and, thereby, to the development of targeted therapeutic approaches.
...
PMID:Biology of chronic myelogenous leukemia. 952 24
1
2
3
4
5
6
7
8
9
10
Next >>