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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
1-2
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pubmed:dateCreated |
1997-2-21
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pubmed:abstractText |
GL331 is a semisynthetic topoisomerase II inhibitor derived from a plant toxin podophyllotoxin. In 72-h exposure assays, LD50 values of GL331 range from 0.5 to 2 microM, which are three- to ten-fold lower than those of its homologous compound etoposide (VP-16), depending on different cancer cell lines including nasopharyngeal, hepatocellular, gastric, cervical and colon cancer types. Apoptotic DNA ladders could be detected when cancer cells were treated with GL331 for 24 h even if the Bcl-2 and Bax protein levels were not altered during the period. Besides acting as topoisomerase II inhibitors, both GL331 and VP-16 decrease the cellular protein tyrosine kinase (PTK) activities in cancer cells. The activities of protein tyrosine phosphatase (PTP) are significantly increased after GL331 treatment but are not affected by VP-16. GL331-induced internucleosomal cleavage can be efficiently prevented by two inhibitors of PTP, sodium orthovanadate and zinc chloride, but not by okadaic acid, which inhibits serine/threonine phosphatase activity. These results indicate that GL331 may induce apoptotic cell death, and that activation of protein tyrosine phosphatases may be involved in this process.
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pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/Antineoplastic Agents, Phytogenic,
http://linkedlifedata.com/resource/pubmed/chemical/DNA, Neoplasm,
http://linkedlifedata.com/resource/pubmed/chemical/Etoposide,
http://linkedlifedata.com/resource/pubmed/chemical/Podophyllotoxin,
http://linkedlifedata.com/resource/pubmed/chemical/Protein Tyrosine Phosphatases,
http://linkedlifedata.com/resource/pubmed/chemical/Protein-Tyrosine Kinases,
http://linkedlifedata.com/resource/pubmed/chemical/Topoisomerase II Inhibitors
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pubmed:status |
MEDLINE
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pubmed:month |
Dec
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pubmed:issn |
0304-3835
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:day |
20
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pubmed:volume |
110
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
77-85
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pubmed:dateRevised |
2010-11-18
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pubmed:meshHeading |
pubmed-meshheading:9018084-Antineoplastic Agents, Phytogenic,
pubmed-meshheading:9018084-Apoptosis,
pubmed-meshheading:9018084-DNA, Neoplasm,
pubmed-meshheading:9018084-DNA Fragmentation,
pubmed-meshheading:9018084-Drug Screening Assays, Antitumor,
pubmed-meshheading:9018084-Etoposide,
pubmed-meshheading:9018084-Lethal Dose 50,
pubmed-meshheading:9018084-Podophyllotoxin,
pubmed-meshheading:9018084-Protein Tyrosine Phosphatases,
pubmed-meshheading:9018084-Protein-Tyrosine Kinases,
pubmed-meshheading:9018084-Topoisomerase II Inhibitors,
pubmed-meshheading:9018084-Tumor Cells, Cultured
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pubmed:year |
1996
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pubmed:articleTitle |
Protein tyrosine phosphatase activities are involved in apoptotic cancer cell death induced by GL331, a new homolog of etoposide.
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pubmed:affiliation |
National Health Research Institutes and Cooperative Clinical Research Laboratory at VGH-Taipei, Taiwan, ROC. tshuang@gate.sinica.edu.tw
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pubmed:publicationType |
Journal Article
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