title: Increased activity of cell surface peptidases in HeLa cells undergoing UV-induced apoptosis is not mediated by caspase 3.
abstract: We have previously shown that in HeLa cells treated with a variety of agents there is an increase in cell surface peptidase (CSP) activity in those cells undergoing apoptosis. The increase in CSP activity observed in UVB-irradiated cells undergoing apoptosis was unaffected when the cultures were treated with the aminopeptidase inhibitor bestatin, and matrix metalloprotease inhibitor BB3103, but greatly enhanced when treated with the caspase 3 inhibitor-DEVD, and reduced in the presence of the poly(ADP-ribose) polymerase (PARP) inhibitor-3-aminobenzamide (3AB). Neither 3AB nor DEVD had an effect on the gross morphology of the apoptotic cells observed under electron microscopy, nor did they have an effect on phosphatidylserine eversion on the cell membrane, or that of PARP cleavage. All the agents except for DEVD had no effect on the level of caspase 3 activity in the cells. The results suggest that other caspases may cleave PARP in these cells. Both 3AB and DEVD treatment reduced the level of actin cleavage seen in the apoptotic cells. The increase in CSP activity observed in cells undergoing UVB-induced apoptosis appears to involve PARP but not caspase 3.
authors.affiliation: School of Medical Sciences, RMIT University, Bundoora 3083, Victoria, Australia.|QCF Cancer Research Unit, Queensland Institute of Medical Research, Herston, Queensland 4006, Australia.
authors.forename: Terrence J
authors.initials: TJ
authors.lastname: Piva
authors.affiliation: QCF Cancer Research Unit, Queensland Institute of Medical Research, Herston, Queensland 4006, Australia.
authors.forename: Catherine M
authors.initials: CM
authors.lastname: Davern
authors.affiliation: QCF Cancer Research Unit, Queensland Institute of Medical Research, Herston, Queensland 4006, Australia.
authors.forename: Paula M
authors.initials: PM
authors.lastname: Hall
authors.affiliation: QCF Cancer Research Unit, Queensland Institute of Medical Research, Herston, Queensland 4006, Australia.
authors.forename: Clay M
authors.initials: CM
authors.lastname: Winterford
authors.affiliation: QCF Cancer Research Unit, Queensland Institute of Medical Research, Herston, Queensland 4006, Australia.
authors.forename: Kay A O
authors.initials: KAO
authors.lastname: Ellem
mesh_terms: D000199:Actins / Q000378:metabolism; D017304:Annexin A5 / Q000378:metabolism; D017209:Apoptosis / Q000187:drug effects / Q000528:radiation effects*; D053148:Caspase 3 / Q000378:metabolism*; D002462:Cell Membrane / Q000201:enzymology*; D048430:Cell Shape / Q000187:drug effects / Q000528:radiation effects; D005434:Flow Cytometry; D006367:HeLa Cells; D006801:Humans; D008854:Microscopy, Electron; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism; D011480:Protease Inhibitors / Q000494:pharmacology; D013194:Staining and Labeling; D014466:Ultraviolet Rays
chemical_list: D000199:Actins; D017304:Annexin A5; D011480:Protease Inhibitors; D011065:Poly(ADP-ribose) Polymerases; D053148:Caspase 3