title: Enzyme-assisted photosensitization activates different apoptotic pathways in Rose Bengal acetate treated HeLa cells.
abstract: Photosensitization of tumor cells after incubation with Rose Bengal acetate (RB-Ac) induces multiple organelle photodamage followed by apoptotic cell death. We used immunocytochemical techniques in multicolor fluorescence microscopy to elucidate whether this occurs through the simultaneous activation of different apoptotic pathways, in HeLa cells. We detected in situ the activated forms of caspases 9 and 3, and the translocation from the mitochondria to the nucleus of the apoptosis inducing factor; DNA electrophoretic techniques were also used to assess the occurrence of nuclear DNA cleavage into either high- or low-molecular-weight fragments. Both the caspase-dependent and caspase-independent apoptotic pathways are activated. The genomic DNA is degraded into high molecular weight molecules only, without the formation of oligonucleosome-sized fragments. The ability of RB-Ac to induce the simultaneous release of apoptogenic signals from different photodamaged organelles makes it an especially powerful cytotoxic agent.
authors.affiliation: Dipartimento di Biologia Animale, Università degli Studi di Pavia, Pavia, Italy. bottone@unipv.it
authors.forename: Maria Grazia
authors.initials: MG
authors.lastname: Bottone
authors.forename: Cristiana
authors.initials: C
authors.lastname: Soldani
authors.forename: Annunzia
authors.initials: A
authors.lastname: Fraschini
authors.forename: Anna Cleta
authors.initials: AC
authors.lastname: Croce
authors.forename: Giovanni
authors.initials: G
authors.lastname: Bottiroli
authors.forename: Tania
authors.initials: T
authors.lastname: Camboni
authors.forename: Anna Ivana
authors.initials: AI
authors.lastname: Scovassi
authors.forename: Carlo
authors.initials: C
authors.lastname: Pellicciari
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects*; D053148:Caspase 3; D053453:Caspase 9; D020169:Caspases / Q000378:metabolism*; D053938:DNA Fragmentation; D006367:HeLa Cells; D006801:Humans; D007150:Immunohistochemistry; D008856:Microscopy, Fluorescence; D017319:Photosensitizing Agents; D012395:Rose Bengal / Q000031:analogs & derivatives* / Q000494:pharmacology; D015398:Signal Transduction
chemical_list: D000970:Antineoplastic Agents; D017319:Photosensitizing Agents; C501991:Rose Bengal acetate; D012395:Rose Bengal; D053148:Caspase 3; D053453:Caspase 9; D020169:Caspases