title: Activation of caspase-3 in HL-60 cells treated with pyrithione and zinc.
abstract: The transition metal zinc (Zn) is an endogenous regulator of apoptosis. The ability of Zn to modulate apoptosis is believed to be mediated by the regulation of caspase activity. Previously, we reported that an acute influx of labile Zn induced apoptosis via activation of caspase in human leukemia HL-60 cells treated with a Zn ionophore (Py, pyrithione) and Zn at 1 and 25 microM, respectively. In the present study, we investigated the involvement of caspase-3 in Py (1 microM)/Zn (25 microM)-induced apoptosis in HL-60 cells. Pro-caspase-3 is an inactive form of caspase-3. The processing of pro-caspase-3, a sign of caspase-3 activation, occurred 6 h after treatment with Py/Zn. Proteolysis of poly (ADP-ribose) polymerase (PARP), a substrate of caspase-3, was also observed 6 h after treatment with Py/Zn. We also confirmed the elevation of caspase-3 activity as an index of the cleavage of amino acid sequences recognized by activated caspase-3. An inhibitor of caspase-3 attenuated the appearance of the DNA ladder. Taken together, these results indicate that the activation of caspase-3 is partly responsible for the induction of apoptosis in Py/Zn-treated HL-60 cells.
authors.affiliation: Department of Pharmaceutics and Biopharmaceutics, Showa Pharmaceutical University, Tokyo, Japan.
authors.forename: Masuo
authors.initials: M
authors.lastname: Kondoh
authors.forename: Emi
authors.initials: E
authors.lastname: Tasaki
authors.forename: Masufumi
authors.initials: M
authors.lastname: Takiguchi
authors.forename: Minoru
authors.initials: M
authors.lastname: Higashimoto
authors.forename: Yoshiteru
authors.initials: Y
authors.lastname: Watanabe
authors.forename: Masao
authors.initials: M
authors.lastname: Sato
mesh_terms: D017209:Apoptosis / Q000187:drug effects*; D053148:Caspase 3; D020169:Caspases / Q000378:metabolism*; D004359:Drug Therapy, Combination; D004789:Enzyme Activation / Q000187:drug effects; D018922:HL-60 Cells; D006801:Humans; D011725:Pyridines / Q000494:pharmacology*; D013871:Thiones; D013997:Time Factors; D015032:Zinc / Q000494:pharmacology*
chemical_list: D011725:Pyridines; D013871:Thiones; C008704:pyrithione; C505407:CASP3 protein, human; D053148:Caspase 3; D020169:Caspases; D015032:Zinc