title: Induction of apoptosis by penta-O-galloyl-beta-D-glucose through activation of caspase-3 in human leukemia HL-60 cells.
abstract: Penta-O-galloyl-beta-D-glucose is structurally related to (-)-epigallocatechin gallate and is isolated from hydrolyzed tannin. Penta-O-galloyl-beta-D-glucose can inhibit tumor promotion by teleocidin. We investigated the effects of penta-O-galloyl-beta-D-glucose and various tea polyphenols on cell viability in human leukemia HL-60 cells. In this study, we demonstrated that penta-O-galloyl-beta-D-glucose was able to induce apoptosis in a concentration- and time-dependent manner; however, other polyphenols were less effective. We further investigated the molecular mechanisms of penta-O-galloyl-beta-D-glucose-induced apoptosis. Treatment with penta-O-galloyl-beta-D-glucose caused induction of caspase-3/CPP32 activity in dose- and time-dependent manner, but not caspase-1 activity, and induced the degradation of poly-(ADP-ribose) polymerase. Pretreatment with acetyl-Asp-Glu-Val-Asp-aldehyde (Ac-DEVD-CHO) and Z-Val-Ala-Asp-fluoromethyl-ketone (Z-VAD-FMK) inhibited penta-O-galloyl-beta-D-glucose-induced DNA fragmentation. Furthermore, treatment with penta-O-galloyl-beta-D-glucose (50 microM) caused a rapid loss of mitochondrial transmembrane potential, release of mitochondrial cytochrome c into cytosol, and subsequent induction of procaspase-9 processing. Our results indicate that penta-O-galloyl-beta-D-glucose allows caspase-activated deoxyribonuclease to enter the nucleus and degrade chromosomal DNA, and induces DFF-45 (DNA fragmentation factor) degradation. These results lead to a working hypothesis that penta-O-galloyl-beta-D-glucose-induced apoptosis is triggered by the release of cytochrome c into the cytosol, procaspase-9 processing, activation of caspase-3, degradation of poly-(ADP-ribose) polymerase, and DNA fragmentation caused by the caspase-activated deoxyribonuclease through the digestion of DFF-45. The induction of apoptosis by penta-O-galloyl-beta-D-glucose may provide a pivotal mechanism for its cancer chemopreventive action.
authors.affiliation: Institute of Biochemistry, College of Medicine, National Taiwan University, Taipei.
authors.forename: M H
authors.initials: MH
authors.lastname: Pan
authors.forename: J H
authors.initials: JH
authors.lastname: Lin
authors.forename: S Y
authors.initials: SY
authors.lastname: Lin-Shiau
authors.forename: J K
authors.initials: JK
authors.lastname: Lin
mesh_terms: D000165:Acridine Orange; D017209:Apoptosis / Q000187:drug effects*; D015153:Blotting, Western; D053148:Caspase 3; D020169:Caspases / Q000378:metabolism*; D002455:Cell Division / Q000187:drug effects; D053938:DNA Fragmentation; D004273:DNA, Neoplasm / Q000096:biosynthesis / Q000302:isolation & purification; D004305:Dose-Response Relationship, Drug; D004591:Electrophoresis, Polyacrylamide Gel; D004789:Enzyme Activation / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D005434:Flow Cytometry; D005456:Fluorescent Dyes; D018922:HL-60 Cells; D006801:Humans; D047348:Hydrolyzable Tannins; D008564:Membrane Potentials / Q000187:drug effects; D008928:Mitochondria / Q000187:drug effects; D000254:Sodium-Potassium-Exchanging ATPase / Q000037:antagonists & inhibitors*; D013347:Subcellular Fractions / Q000187:drug effects; D013634:Tannins / Q000494:pharmacology*
chemical_list: D004273:DNA, Neoplasm; D004791:Enzyme Inhibitors; D005456:Fluorescent Dyes; D047348:Hydrolyzable Tannins; D013634:Tannins; C435084:pentagalloylglucose; C505407:CASP3 protein, human; D053148:Caspase 3; D020169:Caspases; D000254:Sodium-Potassium-Exchanging ATPase; D000165:Acridine Orange