Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0023473 (chronic myeloid leukemia)
 18,916 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

K562 is a cell line with two acrocentric marker chromosomes containing abnormally banded regions (ABRs), derived from a Ph-positive chronic myelogenous leukemia (CML) patient. Using reverse and forward chromosome painting FISH analysis, we found that 9q34, 13q31, and 22q11 regions co-amplified in the ABRs-bearing acrocentric marker chromosomes of K562. Utilizing the ABRs of the cell line as target DNA for cDNA selection, we established a simple procedure for chromosome region-specific cDNA isolation. After first strand cDNA synthesis from fetal brain mRNAs, short fragment cDNAs (sf-cDNAs) were synthesized with a two-step amplification system by use of our modified Degenerate Oligonucleotide Primed Shuttle Polymerase Chain Reaction (DOP-Shuttle-PCR) method. The sf-cDNAs were hybridized onto RNase A treated metaphases from K562, and the ABRs were microdissected and reamplified with DOP-Shuttle-PCR primer-II. The reamplified sf-cDNAs were cloned into a pBluescript vector. Twenty randomly chosen clones were sequenced and classified into 8 groups. Three out of the 8 grouped clones had been mapped to the long arm of chromosome 22 (22q11), whereas the other 5 were novel cDNAs. Quantitative Southern blot analysis indicated that 7 out of the 8 grouped clones (87.5%) were derived from the co-amplified regions.
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PMID:Microdissection-mediated selection of chromosome region-specific cDNAs. 928 14

Reactive aldehydes derived from reducing sugars and peroxidation of lipids covalently modify proteins and may contribute to oxidative tissue damage. We recently described another mechanism for generating reactive aldehydes from free alpha-amino acids. The pathway begins with myeloperoxidase, a heme enzyme secreted by activated neutrophils. Conversion of alpha-amino acids to aldehydes requires hypochlorous acid (HOCl), formed from H2O2 and chloride by myeloperoxidase. When L-serine is the substrate, HOCl generates high yields of glycolaldehyde. We now demonstrate that a model protein, ribonuclease A (RNase A), exposed to free L-serine and HOCl exhibits the biochemical hallmarks of advanced glycation end (AGE) products -- browning, increased fluorescence, and cross-linking. Furthermore, Nepsilon-(carboxymethyl)lysine (CML), a chemically well-characterized AGE product, was generated on RNase A when it was exposed to reagent HOCl-serine, the myeloperoxidase-H2O2-chloride system plus L-serine, or activated human neutrophils plus L-serine. CML production by neutrophils was inhibited by the H2O2 scavenger catalase and the heme poison azide, implicating myeloperoxidase in the cell-mediated reaction. CML was also generated on RNase A by a myeloperoxidase-dependent pathway when neutrophils were activated in a mixture of amino acids. Under these conditions, we observed both L-serine-dependent and L-serine-independent pathways of CML formation. The in vivo production of glycolaldehyde and other reactive aldehydes by myeloperoxidase may thus play an important pathogenic role by generating AGE products and damaging tissues at sites of inflammation.
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PMID:The myeloperoxidase system of human phagocytes generates Nepsilon-(carboxymethyl)lysine on proteins: a mechanism for producing advanced glycation end products at sites of inflammation. 1039 4

Advanced glycation end products (AGEs) derived from glucose are implicated in the pathogenesis of diabetic vascular disease. However, many lines of evidence suggest that other pathways also promote AGE formation. One potential mechanism involves oxidants produced by the NADPH oxidase of neutrophils, monocytes, and macrophages. In vitro studies have demonstrated that glycolaldehyde, a product of serine oxidation, reacts with proteins to form N(epsilon)-(carboxymethyl)lysine (CML), a chemically well-characterized AGE. We used mice deficient in phagocyte NADPH oxidase (gp91-phox(-/-)) to explore the role of oxidants in AGE production in isolated neutrophils and intact animals. Activated neutrophils harvested from wild-type mice generated CML on ribonuclease A (RNase A), a model protein, by a pathway that required L-serine. CML formation by gp91-phox(-/-) neutrophils was impaired, suggesting that oxidants produced by phagocyte NADPH oxidase contribute to the cellular formation of AGEs. To determine whether these observations are physiologically relevant, we used isotope-dilution gas chromatography/mass spectrometry to quantify levels of protein-bound CML in mice suffering from acute peritoneal inflammation. Phagocytes from the gp91-phox(-/-) mice contained much lower levels of CML than those from the wild-type mice. Therefore, oxidants generated by phagocyte NADPH oxidase may play a role in AGE formation in vivo by a glucose-independent pathway.
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PMID:Production of N(epsilon)-(carboxymethyl)lysine is impaired in mice deficient in NADPH oxidase: a role for phagocyte-derived oxidants in the formation of advanced glycation end products during inflammation. 1288 33

This review summarizes data on ambiguous biological functions of ribonucleases (RNases) at tumor growth. In some cases the raised level of enzyme activity in biological fluids can be regarded as an additional marker of malignant growth (pancreas cancer, chronic myeloid leukemia, etc.). At the same time the activity of RNases is often lowered in tumor tissue. High substrate specificity of particular RNases provides metabolic balance between various kinds of RNAs with various half-time exchange turn. RNases are the important factors of epigenetic regulation of gene activity in cells. The activity of RNases is adjustable by inhibitors and other factors, and defines time of existence of different kinds of RNAs. RNases (the modified variants of RNase A, RNases of semen fluid of the cattle, RNase of amphibia oocytes) can be used as anti-tumor therapeutic agents. On the other hand, some inhibitors of RNases of natural or synthetic origin were demonstrated to be perspective drugs that inhibit tumor growth.
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PMID:Ribonucleases in tumor growth. 1978 70