title: A lymphoma cell line resistant to 4-piperidinopiperidine was less sensitive to CPT-11.
abstract: CPT-11 is a promising new anticancer drug in which 4-piperidinopiperidine is a side-chain structure. In the present studies, we examined the role played by 4-piperidinopiperidine in the pharmacological activity of CPT-11. When T-cell lymphoma RVC cells were incubated with 4-piperidinopiperidine at concentrations higher than 50 micrograms/ml, the cells underwent apoptosis with a nucleosomal ladder of chromosomal DNA on agarose gels in a dose-dependent manner. We then established a cell line resistant to 4-piperidinopiperidine (4-pp-R), which was about 20-fold more resistant to 4-piperidinopiperidine than the parent RVC cells. Moreover, 4-pp-R cells showed coresistance to CPT-11. However, the growth rate and cell cycle population of 4-pp-R cells were not different from those of the parent RVC cells, and there were no differences between the two cells lines with regard to their drug transport system. CPT-11-metabolizing activity, their activity and amount of topoisomerase I, or their sensitivity to either SN-38 or etoposide, suggesting that the cytotoxicity of CPT-11 is not a consequence of the activity of its metabolite SN-38. The present studies suggested that resistance to CPT-11 is in part due to insensitivity to 4-piperidinopiperidine and its metabolites, since 4-piperidinopiperidine was cytotoxic and 4-pp-R cells were less sensitive to CPT-11.
authors.affiliation: Department of Bochemistry, Tokyo Dental College, Chiba, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Onishi
authors.forename: M
authors.initials: M
authors.lastname: Oguro
authors.forename: H
authors.initials: H
authors.lastname: Kizaki
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D002166:Camptothecin / Q000031:analogs & derivatives* / Q000494:pharmacology; D002455:Cell Division / Q000187:drug effects; D004264:DNA Topoisomerases, Type I / Q000378:metabolism; D004250:DNA Topoisomerases, Type II / Q000378:metabolism; D019008:Drug Resistance, Neoplasm; D005047:Etoposide / Q000494:pharmacology; D006801:Humans; D000077146:Irinotecan; D016399:Lymphoma, T-Cell / Q000201:enzymology / Q000473:pathology*; D010880:Piperidines / Q000494:pharmacology*; D014407:Tumor Cells, Cultured
chemical_list: C105149:4-(1-piperidino)piperidine; D000970:Antineoplastic Agents; D010880:Piperidines; D005047:Etoposide; D000077146:Irinotecan; D004264:DNA Topoisomerases, Type I; D004250:DNA Topoisomerases, Type II; D002166:Camptothecin