1. Human small cell lung cancer NYH cells resistant to the bisdioxopiperazine ICRF-187 exhibit a functional dominant Tyr165Ser mutation in the Walker A ATP binding site of topoisomerase II alpha
- Author
-
John L. Nitiss, Axelle Renodon-Cornière, Irene Wessel, Maxwell Sehested, Peter Buhl Jensen, Tina K. Sorensen, and Lars H. Jensen
- Subjects
Lung Neoplasms ,Genotype ,Mutant ,Biophysics ,Antineoplastic Agents ,Saccharomyces cerevisiae ,Biology ,Biochemistry ,03 medical and health sciences ,0302 clinical medicine ,Adenosine Triphosphate ,Transformation, Genetic ,Structural Biology ,ATP hydrolysis ,Antigens, Neoplasm ,Drug Resistance, Fungal ,Genetics ,Tumor Cells, Cultured ,Humans ,Binding site ,Carcinoma, Small Cell ,Molecular Biology ,030304 developmental biology ,chemistry.chemical_classification ,0303 health sciences ,Binding Sites ,Dose-Response Relationship, Drug ,Topoisomerase ,Walker motifs ,Wild type ,Cell Biology ,Molecular biology ,Topoisomerase II ,DNA-Binding Proteins ,Enzyme ,DNA Topoisomerases, Type II ,chemistry ,Amino Acid Substitution ,Drug Resistance, Neoplasm ,030220 oncology & carcinogenesis ,Drug resistance ,Mutation ,biology.protein ,Pharmacophore ,Bisdioxopiperazine ,Razoxane ,Cell Division ,Protein Binding - Abstract
Bisdioxopiperazine anti-cancer agents are catalytic inhibitors of topoisomerase II which by unknown means lock the enzyme in a closed clamp form and inhibit its ATPase activity. In order to demarcate a putative pharmacophore, we here describe a novel Tyr165Ser mutation in the enzyme’s Walker A ATP binding site leading to specific bisdioxopiperazine resistance when transformed into a temperature-conditional yeast system. The Tyr165Ser mutation differed from a previously described Arg162Gln by being heterozygous and by purified Tyr165Ser enzyme being drug-resistant in a kinetoplast DNA decatenation enzymatic assay. This suggested dominant nature of Tyr165Ser was supported by co-transformation studies in yeast of plasmids carrying wild type and mutant genes. These results enable a model of the bisdioxopiperazine pharmacophore using the proposed asymmetric ATP hydrolysis of the enzyme.
- Published
- 2002