title: Induction of resistance to etoposide and adriamycin in a human glioma cell line treated with antisense oligodeoxynucleotide complementary to the messenger ribonucleic acid of deoxyribonucleic acid topoisomerase II alpha.
abstract: Acquisition of resistance to anticancer agents is a serious problem for cancer chemotherapy. The present study analyzed the relationship between expression of the alpha isoform of deoxyribonucleic acid (DNA) topoisomerase II (topo II alpha) and chemosensitivity to topo II inhibitors by modulating the level of topo II alpha expression. A phosphorothioate analogue of an 18-nucleotide oligomer which is complementary to the translation initiation site of the human topo II alpha messenger ribonucleic acid sequence was used to suppress the expression of topo II alpha in a human glioma cell line (U373MG). The topo II alpha activity of the treated cells was reduced to 1/3 of untreated cells in a decatenation assay using kinetoplast DNA. Antisense oligoDNA-treated cells showed mild resistance to the topo II inhibitors, etoposide and adriamycin, of about 2.0 fold and 1.5 fold, respectively, compared to control cells. Only partial reduction in the activity of topo II alpha in the glioma cell line can cause a measurable resistance to topo II inhibitors, implying that the degree of topo II expression is correlated with chemosensitivity to topo II inhibitors.
authors.affiliation: Department of Neurological Surgery, Okayama University Medical School.
authors.forename: M
authors.initials: M
authors.lastname: Kuriyama
authors.forename: K
authors.initials: K
authors.lastname: Tsutsui
authors.forename: K
authors.initials: K
authors.lastname: Tsutsui
authors.forename: Y
authors.initials: Y
authors.lastname: Ono
authors.forename: T
authors.initials: T
authors.lastname: Tamiya
authors.forename: K
authors.initials: K
authors.lastname: Matsumoto
authors.forename: T
authors.initials: T
authors.lastname: Furuta
authors.forename: T
authors.initials: T
authors.lastname: Ohmoto
mesh_terms: D000903:Antibiotics, Antineoplastic / Q000494:pharmacology*; D000951:Antigens, Neoplasm; D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology*; D001932:Brain Neoplasms / Q000235:genetics* / Q000473:pathology; D002455:Cell Division / Q000187:drug effects; D002461:Cell Line, Transformed; D002470:Cell Survival / Q000187:drug effects; D004250:DNA Topoisomerases, Type II / Q000235:genetics*; D018076:DNA, Complementary / Q000235:genetics*; D004268:DNA-Binding Proteins; D004305:Dose-Response Relationship, Drug; D004317:Doxorubicin / Q000494:pharmacology*; D018432:Drug Resistance, Multiple / Q000235:genetics*; D019008:Drug Resistance, Neoplasm / Q000235:genetics*; D005047:Etoposide / Q000494:pharmacology*; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D005910:Glioma / Q000235:genetics* / Q000473:pathology; D006801:Humans; D007527:Isoenzymes / Q000037:antagonists & inhibitors / Q000235:genetics*; D016376:Oligonucleotides, Antisense / Q000494:pharmacology*; D012333:RNA, Messenger / Q000235:genetics*; D059005:Topoisomerase II Inhibitors; D014407:Tumor Cells, Cultured / Q000187:drug effects* / Q000473:pathology
chemical_list: D000903:Antibiotics, Antineoplastic; D000951:Antigens, Neoplasm; D000972:Antineoplastic Agents, Phytogenic; D018076:DNA, Complementary; D004268:DNA-Binding Proteins; D007527:Isoenzymes; D016376:Oligonucleotides, Antisense; D012333:RNA, Messenger; D059005:Topoisomerase II Inhibitors; D005047:Etoposide; D004317:Doxorubicin; D004250:DNA Topoisomerases, Type II