Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.2.1.17 (lysozyme)
 21,489 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Two cases of Ph1-negative chronic myelogenous leukemia (CML) are described, they were 66-year-old female and 73-year-old male. Both patients shared all of the following features: presence of anemia, thrombocytopenia and leukocytosis with every stage of neutrophilic differentiation, hypercellular bone marrow with hyperplasia of the degranulated neutrophilic series, diminished neutrophilic alkaline phosphatase, elevated serum lysozyme and vitamin B12 level, mosaic pattern of trisomy 8 and normal karyotypes in chromosome analysis, and markedly increased number of CFU-GM. In addition, bcr rearrangement by Southern blot hybridization was not demonstrated in these patients. The diagnosis of chronic myelomonocytic leukemia was not verified, however, because of the absence of monocytosis in peripheral blood. The existence of so-called Ph1-negative CML like these two cases as a diagnostic entity must be further studied.
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PMID:[So-called Ph1-negative chronic myelogenous leukemia with a mosaic pattern of trisomy 8 and normal karyotypes--report of 2 cases]. 276 71

A new hematopoietic cell line derived from a patient with Philadelphia chromosome (Ph1)-negative myeloblastic leukemia arising from a form of myelodysplastic syndrome (MDS) is described. This cell line, designated TMM, consists of immature cells with the morphological characteristics of young myeloblasts and grows in suspension culture with a doubling time of about 30 hours. By cytochemical analysis the cultured cells were positive for acid phosphatase. They were free of the Epstein-Barr virus-associated nuclear antigen as well as terminal deoxynucleotidyl transferase. Further phenotypic analysis revealed the expression of the myelomonocytic-specific antigen Leu-M1 and receptors for the Fc portion of IgG. Partial differentiation of these cells could be induced by dimethyl sulfoxide, tetradecanoyl phorbol acetate, or hypoxanthine and resulted in cells of the myeloid series expressing lysozyme and receptors for the C3b complement protein. The karyotype was 46,XY, lacked the Ph1 chromosome, and displayed no abnormalities at the light microscopic level. No rearrangement of the bcr-c-abl gene complex was found. This cell line should be useful for studying an important type of the heterogeneous population constituting Ph1-negative myeloblastic leukemia, arising in this instance from MDS, as well as for studying differentiation and proliferation of human pluripotent stem cells.
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PMID:Establishment and characterization of a human myeloid cell line from Philadelphia chromosome-negative myeloblastic leukemia arising in a patient with myelodysplastic syndrome. 347 6

The protooncogene protein-tyrosine kinase c-fes plays an active role in the induction of terminal myeloid differentiation in myeloid leukemia cells. Although p93c-fes contains two autophosphorylation sites, it is not known what role they play in its catalytic or biological activities. To address this question, the major autophosphorylation site at tyrosine 713 was mutated to phenylalanine (YF713), and the mutated cDNA was expressed in a baculovirus system to assess catalytic activity, as well as in an inducible retrovirus to determine its biological activity. The major phosphopeptide in p93c-fes in vitro contained Y713 and was absent in the YF713 mutant, which exhibited an 85% loss of autophosphorylation activity. The catalytic activity of p93c-fesYF713 with either RCM-lysozyme or poly(Glu,Tyr)4:1 as substrate was reduced by 85 and 78%, respectively, in comparison to p93c-fes. Retroviral infection of K562 cells with the c-fes cDNA under the control of the mouse metallothionein promoter increased superoxide formation, phagocytosis, CD13 and CD33 antigen expression, and doubling time 4-6 days after induction. Cells infected with c-fesYF713 exhibited 40% less superoxide formation but similar levels of phagocytosis, CD13/CD33 antigen, and doubling time in comparison to cells infected with c-fes. The level of phosphotyrosine-containing proteins did not markedly differ between K562 cells expressing either neo, c-fes, or c-fesYF713, with the exception of a reduction in the level of a 210-kDa protein specifically in both c-fes-expressing cell lines. The p210 was tentatively identified as bcr-abl, whose level was also reduced in cells expressing c-fes or c-fesYF713.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Effect of the mutation of tyrosine 713 in p93c-fes on its catalytic activity and ability to promote myeloid differentiation in K562 cells. 833 28