Enzyme-assisted photosensitization activates different apoptotic pathways in Rose Bengal acetate treated HeLa cells.
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.
Bottone
Maria Grazia
MG
Dipartimento di Biologia Animale, Università degli Studi di Pavia, Pavia, Italy. bottone@unipv.it
Soldani
Cristiana
C
Fraschini
Annunzia
A
Croce
Anna Cleta
AC
Bottiroli
Giovanni
G
Camboni
Tania
T
Scovassi
Anna Ivana
AI
Pellicciari
Carlo
C
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
D000970:Antineoplastic Agents; D017319:Photosensitizing Agents; C501991:Rose Bengal acetate; D012395:Rose Bengal; D053148:Caspase 3; D053453:Caspase 9; D020169:Caspases