Catalytic inhibition of DNA topoisomerase II by N-benzyladriamycin (AD 288)
| Autor: | Trevor W. Sweatman, D. Parker Suttle, J. Brent Roaten, Yoshihiro Koseki, Leonard Lothstein, Mervyn Israel |
|---|---|
| Rok vydání: | 2000 |
| Předmět: |
Biology
Biochemistry Catalysis chemistry.chemical_compound Tumor Cells Cultured medicine Humans Topoisomerase II Inhibitors Drug Interactions Doxorubicin Etoposide Pharmacology Dose-Response Relationship Drug Topoisomerase DNA Antineoplastic Agents Phytogenic Molecular biology DNA binding site DNA Topoisomerases Type II chemistry Aminosugar Drug Resistance Neoplasm Kinetoplast biology.protein Topoisomerase-II Inhibitor medicine.drug |
| Zdroj: | Biochemical Pharmacology. 60:1621-1628 |
| ISSN: | 0006-2952 |
| DOI: | 10.1016/s0006-2952(00)00472-x |
| Popis: | N-Benzyladriamycin (AD 288) is a highly lipophilic, semi-synthetic congener of doxorubicin (DOX). Unlike DOX, which stimulates double-stranded DNA scission by stabilizing topoisomerase II/DNA cleavable complexes, AD 288 is a catalytic inhibitor of topoisomerase II, capable of preventing topoisomerase II activity on DNA. The concentration of AD 288 required to inhibit the topoisomerase II-catalyzed decatenation of linked networks of kinetoplast DNA was comparable to that for DOX. However, AD 288 did not stabilize cleavable complex formation or stimulate topoisomerase II-mediated DNA cleavage. In addition, AD 288 inhibited the formation of cleavable complexes by etoposide in a concentration-dependent manner. Human CCRF-CEM cells and murine J774. 2 cells exhibiting resistance against DOX, teniposide, or 3'-hydroxy-3'-deaminodoxorubicin through reduced topoisomerase II activity remained sensitive to AD 288. These studies suggest that AD 288 inhibits topoisomerase II activity by preventing the initial non-covalent binding of topoisomerase II to DNA. Since AD 288 is a potent DNA intercalator, catalytic inhibition is achieved by prohibiting access of the enzyme to DNA binding sites. These results also demonstrate that specific substitutions on the aminosugar of DOX can alter the mechanism of topoisomerase II inhibition. |
| Databáze: | OpenAIRE |
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