Enzyme specific activation of benzoquinone ansamycin prodrugs using HuCC49DeltaCH2-beta-galactosidase conjugates.

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.

• Authors: Lanyan Fang, Robert F Battisti, Hao Cheng, Philip Reigan, Yan Xin, Jie Shen, David Ross, Kenneth K Chan, Edward W Martin Jr, Peng George Wang, Duxin Sun
• Journal: Journal of medicinal chemistry (J Med Chem) Vol. 49 Issue 21 Pg. 6290-7 (Oct 19 2006) ISSN: 0022-2623 [Print] United States
• PMID: 17034135 (Publication Type: Journal Article, Research Support, N.I.H., Extramural)

Chemical References

• 17-amino-17-demethoxygeldanamycin -C2-galactose
• Antibodies, Monoclonal
• Antigens, Neoplasm
• Antineoplastic Agents
• Benzoquinones
• Drug Carriers
• Galactosides
• Glycoproteins
• HSP90 Heat-Shock Proteins
• Indicators and Reagents
• Lactams, Macrocyclic
• Prodrugs
• Tetrazolium Salts
• Thiazoles
• tumor-associated antigen 72
• 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium
• Proto-Oncogene Proteins c-akt
• beta-Galactosidase
• 17-aminogeldanamycin
• geldanamycin

Topics

• Antibodies, Monoclonal (chemistry)
• Antigens, Neoplasm (immunology)
• Antineoplastic Agents (administration & dosage, chemistry, pharmacology)
• Benzoquinones (chemistry)
• Cell Line, Tumor
• Colonic Neoplasms
• Drug Carriers
• Drug Delivery Systems
• Galactosides (administration & dosage, chemistry)
• Glycoproteins (immunology)
• HSP90 Heat-Shock Proteins (chemistry, metabolism)
• Humans
• Indicators and Reagents
• Lactams, Macrocyclic (administration & dosage, chemistry)
• Mass Spectrometry
• Models, Molecular
• Prodrugs (administration & dosage, chemistry, pharmacology)
• Protein Binding
• Proto-Oncogene Proteins c-akt (metabolism)
• Tetrazolium Salts
• Thiazoles
• beta-Galactosidase (chemistry)