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Query: UNIPROT:P06889 (Mol)
630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Molecular analyses to determine clonality of T and B cells in malignant lymphoma and leukemia and to detect the (9;22) translocation in chronic myelogenous leukemia are commonly used in clinical molecular biology laboratories. We describe the inclusion of a sensitivity control in each of these assays derived from DNA of well-characterized cell lines. The inclusion of such a sample adds an important quality-control parameter to ensure assay-to-assay reproducibility and to satisfy accreditation and regulatory requirements.
Diagn Mol Pathol 1994 Dec
PMID:Inclusion of a sensitivity control to add a quality-control parameter and improve reproducibility in BCR, immunoglobulin, and T-cell receptor gene-rearrangement studies. 786 38

Cell membrane fluidity (CMF) and transferrin receptor (Tf-R) expression were investigated in K562 cells, a human chronic myelocytic leukemia cell line, treated by gamma-interferon (IFN-gamma). CMF was increased using spin-labeled electron spin resonance techniques, and Tf-R expression was measured by flow cytometric analysis with an EPICS-750 flow cytometer/cell sorter. Treatment of K562 cells in suspension culture with IFN-gamma for as long a time as 6 hr caused an increase in CMF, and then returned to the level of control cells at 12 hr. Conversely, by 24 hr after the beginning of treatment, the rigidity of CMF was increased. Thus, the changes of IFN-gamma-induced CMF was biphasic. While the early change of CMF is related to signal generation and transmission, the later change may reflect changes in lipid compositions and/or cytoskeletal complexes of the plasma cell membrane. A significant increase of Tf-R after 6 hr and 24 hr in number was obtained by treatment of K562 cells with IFN-gamma, but at 12 hr the number of Tf-R did not differ from the control. These results suggested that the early phase of upregulation of Tf-R induced by IFN-gamma was caused by increased CMF, and the late phase of upregulation of Tf-R was due to increased rigidity of CMF. In conclusion, the state of CMF associated with a certain receptor expression in cells is not rigid and can be modulated to some extent by exogenous influences. This may open possibilities of some adjuvant therapeutic measures in malignant diseases by increasing the antigenicity of tumor cells.
Res Commun Mol Pathol Pharmacol 1994 Aug
PMID:Cell membrane fluidity in K562 cells and its relation to receptor expression. 799 58

Southern blotting using radiolabeled probes is a well established technique for the detection of the Philadelphia translocation in the diagnosis of chronic myelogenous leukemia (CML). However, the use of radioisotopes in the clinical setting is often problematic. Because of this we investigated the use of a digoxigenin-labeled probe and chemiluminography in the detection of the Philadelphia translocation. In this study DNA was extracted from 19 bone marrow or blood samples from patients with CML or other malignancies and subjected to Southern blotting with a probe specific for the Philadelphia translocation, Phl/bcr3. The probe was labeled with either 32P or digoxigenin to determine the relative sensitivity and specificity of autoradiography and chemiluminography in the molecular diagnosis of the BCR/abl fusion gene. All 19 samples were tested by both methods. All blots were performed and interpreted by individuals blind to the initial patient diagnosis. In addition, 12 samples (6 positive for CML, 6 negative for CML as determined by Southern blotting with 32P-labeled probe) were subjected to triplicate Southern-blot analyses, with three separate lots of digoxigenin-labeled probe to assay batch to batch variability in the efficacy of the probe. Radiolabeled and digoxigenin-labeled probes resulted in identical diagnoses in all cases. All results obtained by molecular analysis correlated perfectly with the clinical diagnoses of the patients from whom the samples had been obtained. Reanalysis of patient samples with different batches of digoxigenin-labeled probe gave highly reproducible results. With digoxigenin-labeled probe, diagnostic results were obtained after exposure times of less than 1 h at room temperature.(ABSTRACT TRUNCATED AT 250 WORDS)
Diagn Mol Pathol 1994 Jun
PMID:Molecular diagnosis of the Philadelphia chromosome translocation. A comparison of isotopic and chemiluminescent Southern blotting. 806 92

The reliability of histopathological diagnosis in bone marrow specimens from patients with chronic myeloproliferative disorders (CMPD) was evaluated by correlating the histological findings with molecular genetic and cytogenetic analyses of the Ph1-translocation. A rearrangement of m-bcr was detected only in patients (28/30) diagnosed histologically as chronic myeloid leukemia (CML). This finding was supported by the presence of a Ph1-chromosome in 24/26 patients with CML examined. All the patients with other types of CMPD, including polycythemia vera (PV), primary thrombocythemia (PTH) and chronic megakaryocytic-granulocytic myelosis (CMGM), as well as those with unclassifiable CMPD (CMPD.UC) were Ph1-negative (n = 38). The histopathological discrimination of CML from Ph1-negative varieties of CMPD was also reliable for patients with myelofibrosis complicating CML, CMGM and CMPD.UC. The results demonstrate that bone marrow histopathology allows a reliable diagnosis of CML. This is in contrast with hematological data such as high platelet counts which show considerable overlapping in the various forms of CMPD.
Virchows Arch B Cell Pathol Incl Mol Pathol 1993
PMID:Evidence from molecular genetic and cytogenetic analyses that bone marrow histopathology is reliable in the diagnosis of chronic myeloproliferative disorders. 809 57

Human granulocyte-macrophage colony-stimulating factor (GM-CSF) stimulates the proliferation and maturation of normal myeloid progenitor cells and can also stimulate the growth of acute myelogenous leukemia (AML) blasts. GM-CSF is not normally produced by resting cells but is expressed by a variety of activated cells including T lymphocytes, macrophages, and certain cytokine-stimulated fibroblasts and endothelial cells. Production of GM-CSF by cultured AML cells has been demonstrated, and GM-CSF expression by normal myeloid progenitors has been postulated to play a role in myelopoiesis. We have investigated the regulation of expression of GM-CSF in AML cell lines, and our results demonstrate the presence of a strong constitutive promoter element contained within 53 bp upstream of the cap site. We have also identified a negative regulatory element located immediately upstream of the positive regulatory element (within 69 bp of the cap site) that is active in AML cell lines but not T cells or K562 CML cells. Competition transfection and mobility shift studies demonstrate that this activity correlates with binding of a 45-kDa protein.
Mol Cell Biol 1994 Mar
PMID:Characterization of a cell-type-restricted negative regulatory activity of the human granulocyte-macrophage colony-stimulating factor gene. 811 51

P210 BCR/ABL is a chimeric oncogene implicated in the pathogenesis of chronic myelogenous leukemia. BCR sequences have been shown to be required for activation of the tyrosine kinase and transforming functions of BCR/ABL. In this work, we show that two other structural requirements for full transforming activity of P210 BCR/ABL include a functional tyrosine kinase and the presence of tyrosine 1294, a site of autophosphorylation within the tyrosine kinase domain. Replacement of tyrosine 1294 with phenylalanine (1294F) greatly diminishes the transforming activity of BCR/ABL without affecting the specific activity of the protein tyrosine kinase. Expression of an exogenous myc gene in fibroblasts partially complements the transforming capacity of mutant P210 BCR/ABL (1294F). Surprisingly, tyrosine 1294 is not required for efficient induction of growth factor-independence in hematopoietic cell lines by P210 BCR/ABL. These results suggest that autophosphorylation at tyrosine 1294 may be important for recognition and phosphorylation of cellular substrates in the pathway of transformation, but it is not critical for mediating the events which lead to growth factor independence.
Mol Cell Biol 1993 Mar
PMID:SH1 domain autophosphorylation of P210 BCR/ABL is required for transformation but not growth factor independence. 844 9

The cellular homologs of the v-Crk oncogene product are composed exclusively of Src homology region 2 (SH2) and SH3 domains. v-Crk overexpression in fibroblasts causes cell transformation and elevated tyrosine phosphorylation of specific cellular proteins. Among these proteins is a 130-kDa protein, identified as p130cas, that forms a stable complex in vivo with v-Crk. We have explored the role of endogenous Crk proteins in Bcr-Abl-transformed cells. In the K562 human chronic myelogenous leukemia cell line, p130cas is not tyrosine phosphorylated or bound to Crk. Instead, Crk proteins predominantly associate with the tyrosine-phosphorylated proto-oncogene product of Cbl. In vitro analysis showed that this interaction is mediated by the SH2 domain of Crk and can be inhibited with a phosphopeptide containing the Crk-SH2 binding motif. In NIH 3T3 cells transformed by Bcr-Abl, c-Cbl becomes strongly tyrosine phosphorylated and associates with c-Crk. The complex between c-Crk and c-Cbl is also seen upon T-cell receptor cross-linking or with the transforming, tyrosine-phosphorylated c-Cbl. These results indicate that Crk binds to c-Cbl in a tyrosine phosphorylation-dependent manner, suggesting a physiological role for the Crk-c-Cbl complex in Bcr-Abl tyrosine phosphorylation-mediated transformation.
Mol Cell Biol 1996 Jan
PMID:The product of the cbl oncogene forms stable complexes in vivo with endogenous Crk in a tyrosine phosphorylation-dependent manner. 852 28

We investigated the effect of gamma-interferon (gamma-IFN) on three cellular parameters: cell membrane fluidity and expression of two antigens that have been associated with cell proliferation, namely transferrin receptor (Tf-R: a cell surface protein) and Ki-67 antigen (Ki-67: a nuclear protein). We observed small, yet significant changes in the first two parameters, but not the third parameter. These were investigated in K562 cells, a human chronic myelocytic leukemia cell line. These results suggest that the microviscosity changes and the surface Tf-R density were closely associated, and that gamma-IFN was involved in increasing proliferative activity of the cells by decreasing membrane fluidity and upregulating Tf-R expression.
Res Commun Mol Pathol Pharmacol 1996 May
PMID:Gamma-interferon upregulates transferrin receptors and decreases membrane microviscosity in K562 cells. 877 72

We have developed a reverse transcriptase-polymerase chain reaction (RT-PCR) assay to identify breast carcinoma cells in bone marrow aspirates with high sensitivity and specificity. This assay relies on the detection of cytokeratin 19 (K19) RNA by nested primer PCR followed by annealing to a (32P)-labeled internal sequence probe and autoradiography. In reconstitution experiments, this assay is capable of detecting 10 fg of admixed mammary tumor RNA in 1 microgram of normal marrow RNA (a dilution of 1:10(7)). Thirty of 30 primary breast tumor specimens, 19 of 19 cytologically positive bone marrow aspirate specimens, and three of 11 aspirate negative/biopsy positive specimens showed detectable K19 transcript. This assay shows high specificity, with 50 of 52 negative control aspirates showing no detectable amplification product. False-positive amplification was noted in two of 18 aspirates obtained from patients with active chronic myelogenous leukemia. Of stage II and III postsurgical breast carcinoma patients with histologically negative bone marrows and no radiographic bone disease, 14 of 30 were K19 positive by PCR. RT-PCR analysis of K19 transcript is a highly sensitive and specific method of detecting and monitoring low-level metastatic disease in patients with primary carcinoma of the breast. The presence of K19 RNA in histologically negative bone marrows suggests that this assay may prove a powerful monitor for patients undergoing curative therapy as well as a novel prognostic indicator.
Diagn Mol Pathol 1996 Sep
PMID:High-sensitivity detection of minimal residual breast carcinoma using the polymerase chain reaction and primers for cytokeratin 19. 886 30

Acquired von Willebrand disease (vWD) has been described in a few patients with chronic myelocytic leukemia (CML). We present here acquired type 2 vWD associated with CML and provide characterization of an inhibitor to von Willebrand factor (vWF) from this patient. His bleeding time was prolonged. Ristocetin-induced platelet agglutination was abolished whereas botrocetin-mediated aggregation was normal. Multimeric analysis of vWF from patient's plasma showed that larger sizes of multimers were reduced. His past and family histories were negative for bleeding tendency. These results suggested that acquired type 2 vWD was present during his clinical course. The inhibitor was purified by Staphylococcal protein A, suggesting an IgG antibody. Both binding of 125I-vWF to GPIb and platelet agglutination by ristocetin were inhibited by the patient IgG with the concentrations of competing substances necessary to inhibit specific binding by 50% (IC50s) of 260 micrograms/ml and 420 micrograms/ml, respectively. However, the IgG had no effect on these studies mediated by botrocetin. The IgG only reacted with intact vWF and a 39/34 kDa fragment of vWF. These results indicate that the recognition of GPIb binding site(s) on vWF by the IgG is a central pathogenesis of acquired type 2 vWD in this case.
Hematopathol Mol Hematol 1996
PMID:Acquired type 2A von Willebrand disease in chronic myelocytic leukemia. 887 31


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