title: [Analysis of the mechanism of apoptosis induction by PSK].
abstract: Although PSK is an antitumor drug with immunomodulating effects, it has also been shown to have a direct action on cancer cells. This study analyzed the mechanism of the direct action of PSK on cancer cells, focused on the apoptosis-inducing effect. First, the cell growth inhibitory effect of PSK was examined using seven cancer cell lines, and HL60 cells were found to be strongly inhibited. Next, using HL60 cells, the apoptosis-inducing effect of PSK was examined using Annexin-V/Propidium iodide immunostaining and DNA fragmentation. The results indicated that PSK induced the apoptosis of HL60 cells. When the effect of PSK on protein expression of apoptosis-related factors was analyzed using an apoptosis array, over-expression of pro-caspase-3 and under-expression of factors such as cIAP-1, and cIAP-2 were observed. Furthermore, FACS analysis confirmed an increase in percentage of cells expressing activated caspase-3. These findings suggest that PSK induces apoptosis of HL60 cells and inhibits cell proliferation.
authors.affiliation: Dept. of Digestive and General Surgery, Shimane University Faculty of Medicine.
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Hirahara
authors.forename: Masaki
authors.initials: M
authors.lastname: Fujioka
authors.forename: Ayako
authors.initials: A
authors.lastname: Fujieda
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Wada
authors.forename: Tsuneo
authors.initials: T
authors.lastname: Tanaka
mesh_terms: D000903:Antibiotics, Antineoplastic / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D000075747:Baculoviral IAP Repeat-Containing 3 Protein; D053148:Caspase 3 / Q000032:analysis; D045744:Cell Line, Tumor / Q000187:drug effects; D053938:DNA Fragmentation / Q000187:drug effects; D018922:HL-60 Cells; D006801:Humans; D051034:Inhibitor of Apoptosis Proteins / Q000032:analysis; D011509:Proteoglycans / Q000494:pharmacology*; D044767:Ubiquitin-Protein Ligases
chemical_list: D000903:Antibiotics, Antineoplastic; D051034:Inhibitor of Apoptosis Proteins; D011509:Proteoglycans; C010770:polysaccharide-K; C494832:BIRC3 protein, human; D000075747:Baculoviral IAP Repeat-Containing 3 Protein; D044767:Ubiquitin-Protein Ligases; D053148:Caspase 3