Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.25.1 (proteasome)
 28,817 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Rebamipide accelerates healing of gastric ulcers and gastritis but its actions on gastric cancer are not known. Survivin, an anti-apoptosis protein, is overexpressed in stem, progenitor, and cancer cells. In gastric cancer, increased and sustained survivin expression provides survival advantage and facilitates tumor progression and resistance to anti-cancer drugs. Aurora-B kinase is essential for chromosome alignment and mitosis progression but surprisingly its role in gastric cancer has not been explored. We examined in human gastric cancer AGS cells: (1) survivin expression, (2) localization of survivin and Aurora-B, (3) cell proliferation, and (4) effects of specific survivin siRNA and/or rebamipide (free radical scavenging drug) on survivin and Aurora-B expression and cell proliferation. Survivin and Aurora-B are strongly expressed in human AGS gastric cancer cells and co-localize during mitosis. Survivin siRNA significantly reduces AGS cell viability. Rebamipide significantly downregulates in AGS cell survivin expression, its association with Aurora-B and cell proliferation. Rebamipide-induced downregulation of survivin is at the transcription level and does not involve ubiquitin-proteasome pathway.
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PMID:Rebamipide inhibits gastric cancer growth by targeting survivin and Aurora-B. 1599 41

Helicobacter pylori is a recognized cancerogenic bacterial agent in humans, associated with gastritis, peptic ulcer, and gastric cancer. Immunoevasive and immunomodulatory mechanisms underlie the chronic persistence of the bacterium and the active proinflammatory effect of life-long H. pylori infection. In contrast to tumorigenic viruses, which frequently possess factors to influence the host ubiquitin-proteasome system (UPS), nothing is yet known about potential effects of H. pylori in this respect. The majority of H. pylori isolates worldwide possess a pathogenicity island (PAI), the cagPAI, which is involved in IL-8 production and chronic inflammation. We hypothesized that H. pylori and its cagPAI may have an influence on host cell ubiquitin pathways. The effect of H. pylori wild type and isogenic mutants lacking the complete cagPAI (or CagA) on host deubiqutinating enzymes (DUBs) was tested in coincubation experiments with human gastric epithelial cells, using DUB activity profiling. Specific DUBs were identified to be active in gastric cells. Effects on the activity and expression of DUBs were observed in H. pylori-infected cells. In particular, H. pylori caused a strong decrease in the expression and activity of the DUB USP7 which was partially cagPAI- and CagA-dependent. The reduction in USP7 in infected cells at the protein and transcript levels coincided with a decrease in the amounts of the major innate immune hub protein TRAF6 and the tumor suppressor p53. These results are a basis for further investigations into H. pylori modulators of ubiquitin-dependent cellular signaling and their biological function.
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PMID:Helicobacter pylori affects the cellular deubiquitinase USP7 and ubiquitin-regulated components TRAF6 and the tumour suppressor p53. 2113 Dec 31

ANKRD26-related thrombocytopenia (ANKRD26-RT) is an autosomal-dominant thrombocytopenia caused by mutations in the 5'UTR of the ANKRD26 gene. ANKRD26-RT is characterised by dysmegakaryopoiesis and an increased risk of leukaemia. PaCSs are novel particulate cytoplasmic structures with selective immunoreactivity for polyubiquitinated proteins and proteasome that have been detected in a number of solid cancers, in the epithelia of Helicobacter pylori gastritis and related preneoplastic lesions, and in the neutrophils of Schwachman-Diamond syndrome, a genetic disease with neutropenia and increased leukaemia risk. We searched for PaCSs in blood cells from 14 consecutive patients with ANKRD26-RT. Electron microscopy combined with immunogold staining for polyubiquitinated proteins, 20S and 19S proteasome showed PaCSs in most ANKRD26-RT platelets, as in a restricted minority of platelets from healthy controls and from subjects with other inherited or immune thrombocytopenias. In ANKRD26-RT platelets, the PaCS amount exceeded that of control platelets by a factor of 5 (p<0.0001). Immunoblotting showed that the higher PaCS number was associated with increased amounts of polyubiquitinated proteins and proteasome in ANKRD26-RT platelets. PaCSs were also extensively represented in ANKRD26-RT megakaryocytes, but not in healthy control megakaryocytes, and were absent in other ANKRD26-RT and control blood cells. Therefore, large amounts of PaCSs are a characteristic feature of ANKRD26-RT platelets and megakaryocytes, although these novel cell components are also present in a small subpopulation of normal platelets. The widespread presence of PaCSs in inherited diseases with increased leukaemia risk, as well as in solid neoplasms and their preneoplastic lesions, suggests a link of these structures with oncogenesis.
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PMID:Ubiquitin/proteasome-rich particulate cytoplasmic structures (PaCSs) in the platelets and megakaryocytes of ANKRD26-related thrombo-cytopenia. 2332 69