Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.26.9 (ribonuclease)
 6,589 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A clone, YS-T22, of cells from Yoshida sarcoma cell line, YSSF-212T, grown in "serum-free" culture medium produced factors stimulating differentiation of mouse myeloid leukemia cells (M1) to macrophages and granulocytes. The formation of macrophages and granulocytes was accompanied by induction of phagocytosis, locomotive activity, and lysosomal enzyme activities. The rates of induction of these differentiated phenotypes were proportional to the concentration of the factor added and the period of treatment. The factor stimulating differentiation of M1 cells was a heat-labile, nondialyzable proteinaceous substance that was inactivated by trypsin but not by ribonuclease or glycosidases. On diethylaminoethyl cellulose chromatography, the factor stimulating differentiation of M1 cells from conditioned medium of YS-T22 cells was eluted in various fractions with or without activity of the colony-stimulating factor.
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PMID:Characterization of factors stimulating differentiation of mouse myeloid leukemia cells from a Yoshida sarcoma cell line cultured in serum-free medium. 31 74

Expression of the 93-kd tyrosine kinase encoded by the human c-fes proto-oncogene (also known as FES) is restricted to mature hematopoietic cells of the granulocytic and monocytic lineages, suggestive of a function essential to normal myeloid differentiation. However, recent studies have shown that c-fes can transform fibroblasts if sufficient levels of gene expression are achieved. These findings indicate that strict regulation of the c-fes gene is critical to normal myeloid development, whereas elevated c-fes expression may contribute to malignant transformation. In the present study, we compared the c-fes messenger RNA (mRNA) levels in leukemia blasts from patients with myeloid or lymphoid leukemia with those of peripheral monocytes from a normal donor with the use of a quantitative ribonuclease protection assay. The presence of c-fes mRNA was readily detected in both acute myeloid leukemia (AML) and chronic myeloid leukemia (CML) cells, but c-fes mRNA was present in low levels or was absent in lymphoid leukemia cells. The leukemia cells of two of five AML patients and four of four CML patients expressed more c-fes mRNA than monocytes from a normal donor, with more than a threefold elevation in the cells of one CML patient. No evidence of amplification or rearrangement of the c-fes gene was detectable by Southern blot analysis of myeloid leukemia DNA, suggesting that the variation in c-fes mRNA levels are related to differences in transcriptional activity and/or message stability. These results indicate that elevated c-fes expression is a common feature of myeloid leukemia cells that could potentially contribute to the leukemia phenotype.
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PMID:Elevated expression of the c-fes proto-oncogene in adult human myeloid leukemia cells in the absence of gene amplification. 198 16

Using the oxazine dye rhodanile blue, large typical megakaryocytes and small megakaryocytes (micromegakaryocytes) from the bone marrows of normal persons, and from patients with a variety of preleukemic disorders, acute lymphoblastic and nonlymphoblastic leukemia, chronic granulocytic leukemia, and idiopathic thrombocytopenic purpura as an example of nonmalignant but abnormal megakaryocytopoiesis, showed intense pink staining of the cytoplasm. This pink metachromasia was not obliterated by prior digestion with either diastase or ribonuclease, but was markedly diminished or obliterated by preincubation with hyaluronidase, suggesting that the stain may detect a high content of acid mucopolysaccharides in megakaryocytes. Since the stain is simple, direct, and reproducible, it may represent a useful addition to the cytochemistry of megakaryocytes and complement the more complex immunologic techniques available currently.
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PMID:Identification of human megakaryocytes with rhodanile blue. 258 May 2

The activities of serum acid ribonuclease (RNase) were determined in patients with malignant neoplasm or with renal failure. The levels were markedly increased in myelogenous leukemia and renal failure, and only slightly increased in solid cancers, lymphoid malignancies and multiple myeloma. These increases correlated significantly with serum LDH activity in myelogenous leukemia and with creatinine levels in other malignancies or renal failure. The acid RNase content of granulocytes was 22.7-fold higher than that of lymphocytes. The increase of serum acid RNase may suggest an increased granulocyte destruction in myelogenous leukemia and a reduced glomerular filtration in other malignant neoplasms and renal failure.
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PMID:Activities of serum acid ribonuclease in patients with malignant neoplasms or with renal failure. 658 Sep 78

Mouse myeloid leukemia M1 cells were induced to differentiate in vitro into macrophages and granulocytes by various inducers, including dexamethasone. Prostaglandin F2 alpha inhibited the inductions by dexamethasone of phagocytic and lysozyme activities in M1 cells. Prostaglandin F2 alpha stimulated the production of differentiation-inhibiting activity (I-activity) in M1 cells. I-activity production by prostaglandin F2 alpha was decreased by simultaneous treatment with actinomycin D (5 ng/ml) but not with 5-fluoro-2'-deoxyuridine (10 ng/ml). The I-activity was inactivated by heating (70 degrees, 20 min) or by treatment with trypsin but not with mixed glycosidases or ribonuclease, suggesting that I-activity was due to a proteinous substance(s). B-Type prostaglandins also stimulated I-activity production, whereas A-, E- and D-type ones did not. Induction of prostaglandin E2. Retinoic acid stimulated the synthesis and release of prostaglandin F2 alpha and production of I-activity in M1 cells. Indomethacin completely inhibited induction of I-activity by retinoic acid. On the basis of these results, the relationship between I-activity production and prostaglandin F2 alpha production is discussed.
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PMID:Mechanisms of inhibition of mouse myeloid leukemic cell differentiation by prostaglandin F2 alpha. 695 29

By using ribonuclease-gold (RNase-G) probes, ultrastructural localization of ribonucleic acid (RNA) was performed in inflammatory cells from gastric mucosa biopsies of gastric cancer and gastritis, and in peripheral leukocytes from normal subjects as well as from granulocytic leukemia patients. Electron microscopically, the azurophilic granules of monocytes and lymphocytes in gastric mucosa were not labeled by RNase-G, while various cytoplasmic granules of neutrophils, eosinophils and basophils were all positively labeled. Labeling of the peripheral leukocytes from normal subjects was the same as above. It is important to find in the present study that the cytoplasmic granules of the peripheral leukemic cells from granulocytic leukemia patients were not labeled by RNase-G. The significance of the afore-mentioned findings lies on one hand in the fact that it could make a revision of the conventional views of the granular composition. On the other hand, the data indicate that the RNase-G technique is potentially explorable for future clinical utilization.
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PMID:[Labeling of granulocytic granules with RNase-gold probes]. 751 38