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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)
Various kinds of nonrandom chromosomal aberrations have been reported in hematopoietic malignancies. Since the 1980s, many translocation-associated oncogenes and several suppressor oncogenes have been identified and applied for the clinical diagnosis of these malignancies. The former is of major, clinical importance for specific diagnosis made on the basis of molecular detection of the chromosomal translocation, the deregulated expression, and the chimeric mRNA of those genes. Both BCL-1 and BCL-2 genes, associated with mantle zone lymphoma and follicular lymphoma, respectively, belong to the representative deregulated oncogenes by juxtaposition with an immunoglobulin gene enhancer as well as an MYC gene in Burkitt's lymphoma. On the other hand, the MLL gene, associated with infant
leukemia, acute
monocytic leukemia and secondary leukemia, produces chimeric mRNAs between LTG4, 9, and 19 genes as well as the BCR-
ABL
chimeric gene in chronic myelogenous leukemia. The detection of minimal residual disease (MRD) by either polymerase chain reaction (PCR) or reverse transcriptase (RT)-PCR is becoming an essential test during the course of treatment containing bone marrow transplantation, because positive results of the MRD are closely related to poor prognosis and would have great influence on the choice of treatment plans.
...
PMID:[Molecular diagnosis of leukemia and lymphoma]. 817 45
We used specific antisera and immunohistochemical methods to investigate the subcellular localization and expression of Bcr, Abl, and Bcr-Abl proteins in leukemic cell lines and in fresh human leukemic and normal samples at various stages of myeloid differentiation. Earlier studies of the subcellular localization of transfected murine type IV c-Abl protein in fibroblasts have shown that this molecule resides largely in the nucleus, whereas transforming deletion variants are localized exclusively in the cytoplasm. Here, we demonstrate that the murine type IV c-Abl protein is also found in the nucleus when overexpressed in a mouse hematopoietic cell line. However, in both normal and leukemic human hematopoietic cells, c-Abl is discerned predominantly in the cytoplasm, with nuclear staining present, albeit at a lower level. In contrast, normal endogenous Bcr protein, as well as the aberrant p210BCR-
ABL
and p190BCR-
ABL
proteins consistently localize to the cytoplasm in both cell lines and fresh cells. The results with p210BCR-
ABL
were confirmed in a unique Ph1-positive chronic myelogenous leukemia (CML) cell line, KBM5, which lacks the normal chromosome 9 and hence the normal c-Abl product. Because the p210BCR-
ABL
protein appears cytoplasmic in both chronic phase and blast crisis CML cells, as does the p190BCR-
ABL
in Ph1-positive
acute leukemia
, a change in subcellular location of Bcr-Abl proteins between cytoplasm and nucleus cannot explain the different spectrum of leukemias associated with p210 and p190, nor the transition from the chronic to the
acute leukemia
phenotype seen in CML. Further analysis of fresh CML and normal hematopoietic bone marrow cells reveals that p210BCR-
ABL
, as well as the normal Bcr and Abl proteins, are expressed primarily in the early stages of myeloid maturation, and that levels of expression are reduced significantly as the cells mature to polymorphonuclear leukocytes. Similarly, a decrease in Bcr and Abl levels occurs in HL-60 cells induced by DMSO to undergo granulocytic differentiation. The action of p210BCR-
ABL
and its normal counterparts may, therefore, take place during the earlier stages of myeloid development.
...
PMID:Subcellular localization of Bcr, Abl, and Bcr-Abl proteins in normal and leukemic cells and correlation of expression with myeloid differentiation. 840 45
The Philadelphia (Ph) translocation [t(9;22)(q34;q11)] is the most common genetic abnormality in human leukemia; a transposition of the
ABL
gene to the major-breakpoint cluster region (M-BCR) is associated with the pathogenesis in Ph+ chronic myelogenous leukemia (Ph+ CML) and in some cases of Ph+
acute leukemia
(Ph+ AL). Our current understanding of the methylation of human genomes allows us to consider the association between the epigenetic phenomenon and the control of differentiation and proliferation in mammalian cells. In order to determine whether the methylation status of the M-BCR is associated with breakpoint-localization in this region and with the lineage of hematopoietic cells, we have examined 28 patients with Ph+ leukemias, including nine with Ph+ AL, six patients with acute myeloblastic leukemia without Ph (Ph- AML), and five patients with Ph- acute lymphoblastic leukemia (Ph- ALL); using the restriction endonuclease isochizomers, MspI and HpaII. In CML patients in the chronic phase, the hypomethylated status within the normal M-BCR allele is heterogeneous. In contrast, patients with Ph+ CML in the lymphoid blast crisis phase exhibited a 2.5/2.7 kb band with a complete disappearance of the germline M-BCR fragment (type L). This pattern is consistently noted in Ph- ALL cells, and the pattern is quite different from that found in myeloid blast crisis or Ph- AML (type M). In patients with M-BCR-nonrearranged Ph+ ALL, it is suggested that the M-BCR methylation patterns are cell-lineage specific but some Ph+ ALL cells had a hypomethylation pattern that was identical to that observed in Ph- AML, suggesting a distinction of genetic diversity of leukemia cells with the Ph chromosome, especially Ph+ AL.
...
PMID:The methylation status of the major breakpoint cluster region in human leukemia cells, including Philadelphia chromosome-positive cells, is linked to the lineage of hematopoietic cells. 850 75
The Philadelphia chromosome translocation generates a chimeric oncogene, BCR/ABL which causes chronic myelogenous leukemia. Two different fusion proteins can be produced, p190BCR/
ABL
and p210BCR/
ABL
, depending on the location of the breakpoint in BCR. Although the
ABL
tyrosine kinase activity of the resulting oncoprotein is essential for transformation, the exact functional contribution of BCR to transformation is unclear. A novel oncogene containing
ABL
is formed by the (9;12) translocation which fuses part of the ets-family member TEL to c-ABL in patients with
acute leukemia
. In an effort to compare the biological effects of various
ABL
oncogenes, we transformed two different factor-dependent murine hematopoietic cell lines with cDNA's encoding p210BCR/
ABL
, p190BCR/
ABL
, or TEL/ABL. Transfection of each of the three activated
ABL
oncogenes resulted in rapid emergence of growth factor-independence, and 2-4 sublines from each cell line with each oncogene were further studied. Each oncogene induced an increase in the tyrosine phosphorylation of cellular proteins and autophosphorylation of the oncoprotein itself. Overall, the pattern of increased tyrosine phosphorylation was similar in the cell lines, suggesting that many of the major substrates were identical. We specifically examined a series of proteins known to be p210BCR/
ABL
substrates, including rasGAP, Shc, SH-PTP2, SH-PTP1, CRK-L, CBL, paxillin, and STATs, and found that each were also tyrosine phosphorylated in response to p190BCR/
ABL
and TEL/ABL. These results suggest that the function of BCR can be largely replaced by the unrelated protein TEL with regards to transformation of murine hematopoietic cell lines to factor-independence, and support the hypothesis that a major contribution of both fusion partners is to activate the
ABL
tyrosine kinase.
...
PMID:p210BCR/ABL, p190BCR/ABL, and TEL/ABL activate similar signal transduction pathways in hematopoietic cell lines. 880 88
Much of our understanding of the molecular anomalies involved in the process of oncogenesis has resulted from research into malignant hematologic diseases, facilitated by the accessibility of hematopoietic cells. For example, in lymphoid tumors, rearrangement of the genomic DNA can lead to the juxtaposition of proto-oncogenes and the highly active sequences regulating synthesis of immunoglobulins or T-cell receptors. The subsequent malignancy results from an uncontrolled overexpression of a normal protein. This type of "quantitative" anomaly occurs in follicular lymphomas where B-cells overexpress the normal BCL2 protein which inhibits apoptosis, contributing to immortalization of the B done. The same type of rearrangement process can approach gene fragments which fusion and lead to production of a highly oncogenic chimerical or truncated abnormal protein. Such "qualitative" anomalies occur in myeloid hemopathies. Both types of anomalies involve genes controlling the cell cycle, cell differentiation or cell death (apoptosis), in particular transcription factors (for example, E2A, RARA, MYC) and molecules involved in signal transduction (for example RAS,
ABL
,
LCK
). A molecular anomaly can be detected in approximately 30% of all cases of
acute leukemia
and in up to 75% of the non-Hodgkin lymphomas. Analysis of the junction fragments of the different heavy chains of the immunoglobulins produced in these cases provides a specific marker for detecting the B or T-cell clone in digestive or skin biopsies. For example, detection of a BCR-
ABL
transcript in a patient with primary thrombocythemia or an atypical myeloproliferative syndrome can be diagnostic and detection of the donal immunoglobulin or T-cell receptor rearrangement can confirm the malignant nature of the lymphoid proliferation. Molecular markers also have prognostic value allowing patient stratification and more adapted therapy. Molecular anomalies detected in malignant hematologic diseases are thus examples of nearly perfect "tumor-specific" markers.
...
PMID:[Molecular anomalies in malignant hemopathies]. 923 51
We report here a naturally occurring isoform of the human beta chain common to the receptors for granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin-3 (IL-3), and IL-5 (GMRbetaC) with a truncated intracytoplasmic tail caused by deletion of a 104-bp exon in the membrane-proximal region of the chain. This beta intracytoplasmic truncated chain (betaIT) has a predicted tail of 46 amino acids, instead of 432 for betaC, with 23 amino acids in common with betaC and then a new sequence of 23 amino acids. In primary myeloid cells, betaIT comprised approximately 20% of the total beta chain message, but was increased up to 90% of total in blast cells from a significant proportion of patients with
acute leukemia
. Specific anti-betaIT antibodies demonstrated its presence in primary myeloid cells and cell lines. Coexpression of betaIT converted low-affinity GMRalpha chains (KD 2.5 nmol/L) to higher-affinity alphabeta complexes (KD 200 pmol/L). These could bind
JAK2
that was tyrosine-phosphorylated by stimulation with GM-CSF. betaIT did not support GM-CSF-induced proliferation when cotransfected with GMRalpha into CTLL-2 cells. Therefore, it may interfere with the signal-transducing properties of the betaC chain and play a role in the pathogenesis of leukemia.
...
PMID:A truncated isoform of the human beta chain common to the receptors for granulocyte-macrophage colony-stimulating factor, interleukin-3 (IL-3), and IL-5 with increased mRNA expression in some patients with acute leukemia. 941 69
The ETV6 (TEL) locus at chromosome band 12p 13 is a major site of translocations in
acute leukemia
, particularly in childhood acute lymphoblastic leukemia (ALL). In cases with translocations involving ETV6, the normal ETV6 allele is often deleted. In addition, loss of heterozygosity of ETV6 is frequently observed in childhood'ALL. Thus, it has been suggested that ETV6 may have an anti-oncogenic role to play, in addition to its oncogenic role. We have described an unusual case of ALL in which ETV6 is found fused to the
ABL
gene;
ABL
is normally activated by fusion to the BCR gene in the 9:22 translocation. We expanded the primary cells from this ETV6/
ABL
rearranged case of ALL in SCID animals and analyzed them for expression of both ETV6/
ABL
and the normal ETV6 mRNA. We found that both the rearranged and normal ETV6 mRNAs are expressed in the expanded cell population. Furthermore, sequence analysis of the ETV6 PCR product revealed no point mutations which would influence the amino acid sequence. Thus, deletion of the second ETV6 allele is not necessary for the transformation to leukemia by ETV6/
ABL
.
...
PMID:The second ETV6 allele is not necessarily deleted in acute leukemias with a ETV6/ABL fusion. 952 2
In
acute leukemia
(AL) with a late-appearing Philadelphia (la-Ph) translocation, it is unclear whether these translocations arise from the same molecular event as classical Ph translocations. In order to elucidate the molecular events of la-Ph and subsequent translocations of la-Ph leukemia, we performed molecular analysis on the complex rearrangements, in a cell line, MY, which was established from bone marrow mononuclear cells of a patient with a la-Ph acute biphenotypic leukemia. This la-Ph, expressing an acute lymphoblastic leukemia (ALL)-type BCR/ABL transcript, produces a novel P180BCR/
ABL
fusion protein reflecting deletion of 174 bases (58 amino acids) encoded by the a2 exon of the
ABL
gene. An immune complex kinase assay showed that this protein had autophosphorylation activity. Fluorescence in situ hybridization (FISH) in conjunction with G-banding analysis revealed that the initial der(9)t(9;22)(q34;q11) progressed to a der(9)(9pter-->9q34::22q11-->22q13::5q11.2 -->5q15:: 10q23-->10qter) by, first, a three-way translocation among the der(9)t(9;22)(q34;q11), chromosome 5, and the normal chromosome 22, and then a subsequent translocation with chromosome 10. Moreover, both the end-stage leukemic cells of the patient and the MY cell line had another translocation, t(X;12)(p11.2;p13). The 12p breakpoint was located near the ETV6 gene by analysis of pulsed-field gel electrophoresis, but transcription of ETV6 was unaffected. Tumorigenicity analysis indicated that an additional translocation, t(2;3)(p16;q29), may have caused a more malignant clone, because only MY cells with the t(2;3)(p16;q29) were capable of growing subcutaneously in nude mice within 40 days. The molecular events of leukemogenesis and leukemic progression in the present la-Ph AL occurred by accumulation of unique translocations. This cell line, MY, expressing a novel variant P180BCR/
ABL
protein with a deletion of the a2 exon of the
ABL
gene, may be useful for elucidating the pathophysiology of this fusion protein and for studying ETV6-related leukemogenesis and t(2;3), as well as the molecular mechanisms of the complex translocations.
...
PMID:Establishment of a cell line with variant BCR/ABL breakpoint expressing P180BCR/ABL from late-appearing Philadelphia-positive acute biphenotypic leukemia. 979 May 3
We report a patient with Philadelphia (Ph)-positive, BCR-
ABL
rearrangement positive, chronic myeloid leukemia (CML) with a prolonged chronic phase of 24 years who was first prescribed alpha-2 interferon 22 years after initial diagnosis. This therapy was tolerated poorly on account of thrombocytopenia, but an eventual major cytogenetic response was followed soon afterwards by transformation to terminal acute myeloid leukemia (AML). Cytogenetic studies indicated that the transformed myeloblasts were karyotypically normal and Ph negative. Although polymerase chain reaction (PCR) analysis of total leukemic mRNA remained BCR-
ABL
positive, other molecular studies, including Southern blotting and fluorescent in situ hybridization (FISH) analyses, showed that myeloblasts were BCR-
ABL
rearrangement negative. PCR-based clonality studies using an X-chromosome-linked restriction fragment polymorphism within the phosphoglycerate kinase gene (PGK1) further showed that the Ph-negative blast cells had a different clonal origin from the Ph-positive clone of chronic phase. We suggest that cases of underlying Ph-negative leukemic transformation in Ph-positive CML warrant further study and should be considered for trial of intensive remission induction therapy as appropriate for
acute leukemia
.
...
PMID:Clonally unrelated BCR-ABL-negative acute myeloblastic leukemia masquerading as blast crisis after busulphan and interferon therapy for BCR-ABL-positive chronic myeloid leukemia. 1004 47
The Philadelphia chromosome is present in a heterogeneous group of leukemias. It is most commonly associated with chronic myelogenous leukemia (CML) and B-lineage acute lymphoblastic leukemia (ALL) being found in more than 95% and 15-25% of cases respectively. We undertook a study to determine the morphologic, phenotypic and molecular diversity of Philadelphia positive de novo
acute leukemia
patients seen at our institution over the past 3 1/2 years. Twenty-one patients with de novo
acute leukemia
were found to have the Philadelphia chromosome by cytogenetic studies. They consisted of 3 patients with acute myelogenous leukemia (AML), 1 biphenotypic leukemia and 17 ALL patients. Of the patients with ALL, 16 were of B-lineage while 1 had a T-cell phenotype. Ten patients expressed the p210 BCR-
ABL
transcript alone and 10 expressed only the p190 BCR-
ABL
transcript. One patient had co-expression of p190 and p210 b3a2 BCR-
ABL
transcripts. Thus the Philadelphia chromosome can be found in a diverse cohort of morphologic and immunologic subtypes of de novo
acute leukemia
reflecting the heterogeneity of lineage involvement in this disease.
...
PMID:Molecular and phenotypic spectrum of de novo Philadelphia positive acute leukemia. 1056 81
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