title: Analysis of inhibition of topoisomerase IIalpha and cancer cell proliferation by ingenolEZ.
abstract: We previously reported that many ingenol compounds derived from Euphorbia kansui exhibit topoisomerase inhibitory activity and/or inhibitory activity of cell proliferation. The inhibitory effects of 20-O-(2'E,4'Z-decadienoyl) ingenol and 3-O-(2'E,4'Z-decadienoyl)-ingenol among these compounds on topoisomerase II activity and on the cell proliferative activity and arrest phase of the cell cycle were studied using a mouse breast cancer (MMT) cell line. Although 20-O-ingenolEZ exerted inhibitory effects on both topoisomerase II activity and cell proliferative activity, 3-O-ingenolEZ exerted inhibitory activity on neither. The 20-O-ingenolEZ-induced cell arrest of MMT-cell proliferation led to a cell cycle arrest in the G2/M phase. Topoisomerase II inhibition can be divided into the poison and catalytic inhibitor types. A checkpoint mechanism is activated when cells are treated with these topoisomerase II inhibitors. Poison-type inhibition occurs via induction of the DNA damage checkpoint and the catalytic-type inhibition occurs via induction of the DNA-decatenation checkpoint, suggestive of distinct checkpoint reactions. 20-O-ingenolEZ inhibited topoisomerase IIalpha activity through inhibition of ATPase, and induced DNA-decatenation checkpoint without signaling for phosphorylation of H2AX.
authors.affiliation: Department of Chemistry, College of Humanities and Sciences, Nihon University, Tokyo, Japan.
authors.forename: Chisato
authors.initials: C
authors.lastname: Yoshida
authors.forename: Kazsuyoshi
authors.initials: K
authors.lastname: Hishiyama
authors.forename: Khosuke
authors.initials: K
authors.lastname: Miyazaki
authors.forename: Manami
authors.initials: M
authors.lastname: Watanabe
authors.forename: Masahiro
authors.initials: M
authors.lastname: Kanbe
authors.forename: Yuta
authors.initials: Y
authors.lastname: Yamada
authors.forename: Keiithi
authors.initials: K
authors.lastname: Matsuzaki
authors.forename: Kiichi
authors.initials: K
authors.lastname: Miyashita
authors.forename: Susumu
authors.initials: S
authors.lastname: Kitanaka
authors.forename: Shohei
authors.initials: S
authors.lastname: Miyata
mesh_terms: D000818:Animals; D000951:Antigens, Neoplasm; D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology*; D002455:Cell Division / Q000187:drug effects; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D004250:DNA Topoisomerases, Type II; D004268:DNA-Binding Proteins / Q000037:antagonists & inhibitors*; D004224:Diterpenes / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D028481:Euphorbia / Q000737:chemistry; D016195:G2 Phase / Q000187:drug effects; D051379:Mice; D059005:Topoisomerase II Inhibitors
chemical_list: D000951:Antigens, Neoplasm; D000972:Antineoplastic Agents, Phytogenic; D004268:DNA-Binding Proteins; D004224:Diterpenes; D004791:Enzyme Inhibitors; D059005:Topoisomerase II Inhibitors; D004250:DNA Topoisomerases, Type II; C008125:ingenol