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rdf:type | |
lifeskim:mentions | |
pubmed:dateCreated |
1997-11-10
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pubmed:abstractText |
Selective delivery of lethal concentrations of drugs to tumors, allowing the latter to be eradicated without damage to other tissues, continues to be a major goal in cancer chemotherapy. Prodrugs (i.e. drugs that have been derivatized to prevent uptake into cells or interaction with targets), activated by enzyme-monoclonal antibody conjugates positioned at tumor sites, offer promise for achieving this objective. Methotrexate alpha-peptides (derivatives in which an amino acid is linked to the alpha-carboxyl group of the glutamate moiety) are ideal prodrugs, since they are not transported into cells and can be converted to the parent drug by carboxypeptidases. The L,L-diastereomer of MTX-alpha-Phe, synthesized in good yield by treatment of the p-nitrophenyl ester of 4-amino-4-deoxy-10-methylpteroic acid with Glu-alpha-Phe, was hydrolyzed readily by carboxypeptidase A (CP-A). Conjugate was prepared by derivatizing the enzyme and monoclonal antibody KS1/4 with linkers containing maleimide and sulfhydryl groups, respectively; interaction of these groups to form a stable thioether bond joined the proteins. When administered in vitro to UCLA-P3 human lung adenocarcinoma cells (ca. 5 x 10(4) antibody binding sites/cell) that had been pre-treated with the conjugate (whose antibody KS1/4 is targeted to these cells), and excess conjugate removed by extensive washing, MTX-Phe (ID50 = 6.3 x 10(-8) M) approached the toxicity of MTX (ID50 = 4.5 x 10(-8) M). In the absence of conjugate, MTX-Phe was much less toxic (ID50 = 2.2 x 10(-6) M).
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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,
http://linkedlifedata.com/resource/pubmed/chemical/Carboxypeptidases,
http://linkedlifedata.com/resource/pubmed/chemical/Immunoconjugates,
http://linkedlifedata.com/resource/pubmed/chemical/Methotrexate,
http://linkedlifedata.com/resource/pubmed/chemical/Phenylalanine,
http://linkedlifedata.com/resource/pubmed/chemical/Prodrugs,
http://linkedlifedata.com/resource/pubmed/chemical/methotrexate-alpha-alanine,
http://linkedlifedata.com/resource/pubmed/chemical/methotrexate-alpha-phenylalanine
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pubmed:status |
MEDLINE
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pubmed:issn |
0065-2571
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:volume |
37
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
77-92
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pubmed:dateRevised |
2004-11-17
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pubmed:meshHeading |
pubmed-meshheading:9381987-Animals,
pubmed-meshheading:9381987-Antineoplastic Agents,
pubmed-meshheading:9381987-Biotransformation,
pubmed-meshheading:9381987-Carboxypeptidases,
pubmed-meshheading:9381987-Drug Resistance, Neoplasm,
pubmed-meshheading:9381987-Humans,
pubmed-meshheading:9381987-Hydrolysis,
pubmed-meshheading:9381987-Immunoconjugates,
pubmed-meshheading:9381987-Methotrexate,
pubmed-meshheading:9381987-Phenylalanine,
pubmed-meshheading:9381987-Prodrugs,
pubmed-meshheading:9381987-Tumor Cells, Cultured
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pubmed:year |
1997
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pubmed:articleTitle |
Development of methotrexate alpha-peptides as prodrugs for activation by enzyme-monoclonal antibody conjugates.
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pubmed:affiliation |
Department of Molecular and Experimental Medicine, Scripps Research Institute, La Jolla, CA 92037, USA.
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pubmed:publicationType |
Journal Article
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