title: Differential effects of procaspase-3 activating compounds in the induction of cancer cell death.
abstract: The evasion of apoptosis is a key characteristic of cancer, and thus strategies to selectively induce apoptosis in cancer cells hold considerable promise in personalized anticancer therapy. Structurally similar procaspase activating compounds PAC-1 and S-PAC-1 restore procaspase-3 activity through the chelation of inhibitory zinc ions in vitro, induce apoptotic death of cancer cells in culture, and reduce tumor burden in vivo. Ip or iv administrations of high doses of PAC-1 are transiently neurotoxic in vivo, while S-PAC-1 is safe even at very high doses and has been evaluated in a phase I clinical trial of pet dogs with spontaneously occurring lymphoma. Here we show that PAC-1 and S-PAC-1 have similar mechanisms of cell death induction at low concentrations (less than 50 μM), but at high concentrations PAC-1 displays unique cell death induction features. Cells treated with a high concentration of PAC-1 have a distinctive gene expression profile, unusual cellular and mitochondrial morphology, and an altered intracellular Ca(2+) concentration, indicative of endoplasmic reticulum (ER) stress-induced apoptosis. These studies suggest strategies for anticancer clinical development, specifically bolus dosing for PAC-1 and continuous rate infusion for S-PAC-1.
authors.affiliation: Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States.
authors.forename: Diana C
authors.initials: DC
authors.lastname: West
authors.forename: Yan
authors.initials: Y
authors.lastname: Qin
authors.forename: Quinn P
authors.initials: QP
authors.lastname: Peterson
authors.forename: Diana L
authors.initials: DL
authors.lastname: Thomas
authors.forename: Rahul
authors.initials: R
authors.lastname: Palchaudhuri
authors.forename: Karen C
authors.initials: KC
authors.lastname: Morrison
authors.forename: Pamela W
authors.initials: PW
authors.lastname: Lucas
authors.forename: Amy E
authors.initials: AE
authors.lastname: Palmer
authors.forename: Timothy M
authors.initials: TM
authors.lastname: Fan
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Hergenrother
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D001812:Blood-Brain Barrier / Q000187:drug effects / Q000378:metabolism; D002118:Calcium / Q000378:metabolism; D053148:Caspase 3 / Q000378:metabolism*; D016923:Cell Death / Q000187:drug effects*; D045744:Cell Line, Tumor; D004285:Dogs; D005260:Female; D018922:HL-60 Cells; D006367:HeLa Cells; D006801:Humans; D006835:Hydrazones / Q000494:pharmacology; D051379:Mice; D018613:Microscopy, Confocal; D046529:Microscopy, Electron, Transmission; D010879:Piperazines / Q000494:pharmacology; D015032:Zinc / Q000378:metabolism
chemical_list: C514579:(4-benzylpiperazin-1-yl)acetic acid (3-allyl-2-hydroxybenzylidene)hydrazine; D006835:Hydrazones; D010879:Piperazines; D053148:Caspase 3; D015032:Zinc; D002118:Calcium