title: Induction of apoptosis and inhibition of DNA topoisomerase-I in K-562 cells by a marine microalgal polysaccharide.
abstract: We have previously purified an extracellular polysaccharide, D-galactan sulfate associated with L(+)-lactic acid, produced from a marine microalga Dinoflagellate Gymnodinium sp. A3 (GA3). The GA3 polysaccharide, irrespective of presence or absence of lactic acid, exhibited significant cytotoxicity, which is based on an induction of apoptotic cell death, toward human myeloid leukemia K562 cells. Furthermore, we found that the GA3 polysaccharide with or without lactic acid possesses an inhibitory effect on topoisomerase-I (topo-I). The potent cytotoxic effect of GA3 polysaccharide may result from its inhibitory effect on topo-I, because the topo-I inhibition is known to trigger apoptotic cell death.
authors.affiliation: Second Department of Surgery, University of Tokushima School of Medicine, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Sogawa
authors.forename: T
authors.initials: T
authors.lastname: Yamada
authors.forename: T
authors.initials: T
authors.lastname: Sumida
authors.forename: H
authors.initials: H
authors.lastname: Hamakawa
authors.forename: H
authors.initials: H
authors.lastname: Kuwabara
authors.forename: M
authors.initials: M
authors.lastname: Matsuda
authors.forename: Y
authors.initials: Y
authors.lastname: Muramatsu
authors.forename: H
authors.initials: H
authors.lastname: Kose
authors.forename: K
authors.initials: K
authors.lastname: Matsumoto
authors.forename: Y
authors.initials: Y
authors.lastname: Sasaki
authors.forename: K
authors.initials: K
authors.lastname: Okutani
authors.forename: K
authors.initials: K
authors.lastname: Kondo
authors.forename: Y
authors.initials: Y
authors.lastname: Monden
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D004141:Dinoflagellida / Q000737:chemistry*; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D006801:Humans; D020014:K562 Cells; D011134:Polysaccharides / Q000494:pharmacology*; D059004:Topoisomerase I Inhibitors
chemical_list: D004791:Enzyme Inhibitors; D011134:Polysaccharides; D059004:Topoisomerase I Inhibitors