Abstract
To activate prodrugs for cancer treatment, an anti-TAG-72 antibody (HuCC49DeltaCH2) was used for delivery of an activation enzyme (beta-galactosidase) to specifically activate a geldanamycin prodrug (17-AG-C2-Gal) against colon cancer. The geldanamycin prodrug 17-AG-C2-Gal was synthesized by coupling a galactose-amine derivative with geldanamycin at the C-17 position. Molecular docking with two different programs (Affinity and Autodock) showed that the prodrug (17-AG-C2-Gal) was unable to bind to Hsp90; however, the product (17-AG-C2), enzymatically cleaved by beta-galactosidase conjugate, bound to Hsp90 in a similar way as geldanamycin and 17-AG. The computational docking results were further confirmed in experimental testing by the tetrazolium [3-(4,5-dimethythiazol-2-yl)]-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium assay and mass spectrometry. HuCC49DeltaCH2 was chemically conjugated to beta-galactosidase. The antibody-enzyme conjugate was able to target tumor antigen TAG-72 with the well-preserved enzymatic activity to activate 17-AG-C2-Gal prodrug. The released active drug 17-AG-C2 was demonstrated to induce up to 70% AKT degradation and enhance anticancer activity by more than 25-fold compared to the prodrug.
Publication types
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Research Support, N.I.H., Extramural
MeSH terms
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Antibodies, Monoclonal / chemistry*
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Antigens, Neoplasm / immunology*
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Antineoplastic Agents / administration & dosage
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Antineoplastic Agents / chemistry*
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Antineoplastic Agents / pharmacology
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Benzoquinones / chemistry*
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Cell Line, Tumor
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Colonic Neoplasms
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Drug Carriers
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Drug Delivery Systems
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Galactosides / administration & dosage
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Galactosides / chemistry*
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Glycoproteins / immunology*
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HSP90 Heat-Shock Proteins / chemistry
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HSP90 Heat-Shock Proteins / metabolism
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Humans
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Indicators and Reagents
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Lactams, Macrocyclic / administration & dosage
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Lactams, Macrocyclic / chemistry*
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Mass Spectrometry
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Models, Molecular
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Prodrugs / administration & dosage
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Prodrugs / chemistry*
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Prodrugs / pharmacology
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Protein Binding
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Proto-Oncogene Proteins c-akt / metabolism
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Tetrazolium Salts
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Thiazoles
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beta-Galactosidase / chemistry*
Substances
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17-amino-17-demethoxygeldanamycin -C2-galactose
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Antibodies, Monoclonal
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Antigens, Neoplasm
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Antineoplastic Agents
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Benzoquinones
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Drug Carriers
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Galactosides
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Glycoproteins
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HSP90 Heat-Shock Proteins
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Indicators and Reagents
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Lactams, Macrocyclic
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Prodrugs
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Tetrazolium Salts
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Thiazoles
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tumor-associated antigen 72
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3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium
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Proto-Oncogene Proteins c-akt
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beta-Galactosidase
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17-aminogeldanamycin
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geldanamycin