title: Caspase-dependent and -independent suppression of apoptosis by monoHER in Doxorubicin treated cells.
abstract: Doxorubicin (DOX) is an antitumour agent for different types of cancer, but the dose-related cardiotoxicity limits its clinical use. To prevent this side effect we have developed the flavonoid monohydroxyethylrutoside (monoHER), a promising protective agent, which did not interfere with the antitumour activity of DOX. To obtain more insight in the mechanism underlying the selective protective effects of monoHER, we investigated whether monoHER (1 mM) affects DOX-induced apoptosis in neonatal rat cardiac myocytes (NeRCaMs), human endothelial cells (HUVECs) and the ovarian cancer cell lines A2780 and OVCAR-3. DOX-induced cell death was effectively reduced by monoHER in heart, endothelial and A2780 cells. OVCAR-3 cells were highly resistant to DOX-induced apoptosis. Experiments with the caspase-inhibitor zVAD-fmk showed that DOX-induced apoptosis was caspase-dependent in HUVECs and A2780 cells, whereas caspase-independent mechanisms seem to be important in NeRCaMs. MonoHER suppressed DOX-dependent activation of the mitochondrial apoptotic pathway in normal and A2780 cells as illustrated by p53 accumulation and activation of caspase-9 and -3 cleavage. Thus, monoHER acts by suppressing the activation of molecular mechanisms that mediate either caspase-dependent or -independent cell death. In light of the current work and our previous studies, the use of clinically achievable concentrations of monoHER has no influence on the antitumour activity of DOX whereas higher concentrations as used in the present study could influence the antitumour activity of DOX.
authors.affiliation: Department of Medical Oncology, VU University Medical Center, 1081 HV, Amsterdam, The Netherlands. ame.bruynzeel@vumc.nl
authors.forename: A M E
authors.initials: AM
authors.lastname: Bruynzeel
authors.forename: M A
authors.initials: MA
authors.lastname: Abou El Hassan
authors.forename: E
authors.initials: E
authors.lastname: Torun
authors.forename: A
authors.initials: A
authors.lastname: Bast
authors.forename: W J F
authors.initials: WJ
authors.lastname: van der Vijgh
authors.forename: F A E
authors.initials: FA
authors.lastname: Kruyt
mesh_terms: D000903:Antibiotics, Antineoplastic / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D020169:Caspases / Q000502:physiology*; D002453:Cell Cycle / Q000187:drug effects; D002460:Cell Line; D019610:Cytoprotection; D004305:Dose-Response Relationship, Drug; D004317:Doxorubicin / Q000494:pharmacology*; D042783:Endothelial Cells / Q000187:drug effects; D004789:Enzyme Activation / Q000187:drug effects; D005419:Flavonoids / Q000494:pharmacology*; D006801:Humans; D032383:Myocytes, Cardiac / Q000187:drug effects; D016159:Tumor Suppressor Protein p53 / Q000032:analysis; D051028:bcl-2-Associated X Protein / Q000032:analysis
chemical_list: D000903:Antibiotics, Antineoplastic; D005419:Flavonoids; D016159:Tumor Suppressor Protein p53; D051028:bcl-2-Associated X Protein; D004317:Doxorubicin; D020169:Caspases