Caspase-2: a possible trigger of apoptosis induced in A-549 tumor cells by ZnPc photodynamic treatment.
Photodynamic therapy applied to cell cultures represents a widely accepted experimental method to investigate molecular mechanisms that lead to apoptotic cell death. In this context the subcellular localization of photosensitizers seems to be a significant factor in order to determine the apoptotic pathway that could be activated. We have characterized the experimental conditions that induce apoptotic cell death in A-549 cells incubated with ZnPc and irrradiated with red light. Previously we have found that in this cell line the drug is localized in the Golgi apparatus after 3-h incubation. Indirect immunofluorescence analysis of the events that lead to apoptosis made possible the detection of caspase-2 activation in the Golgi region immediately after photodynamic treatments. A few minutes later, the morphology of this organelle starts to disrupt and just 6 h after treatment the nuclei appear affected showing the fragmented appearance typical of apoptotic cell death. From this results we assume that following the photodynamic treatment of A-549 cells with ZnPc, the activation of caspase-2 in the Golgi apparatus could begin to initiate immediately the apoptotic process.
Cristóbal
Javier
J
Departamento de Biología, Facultad de Ciencias, Universidad Autónoma de Madrid, Cantoblanco, Madrid, Spain.
Stockert
Juan C
JC
Villanueva
Angeles
A
Rello-Varona
Santiago
S
Juarranz
Angeles
A
Cañete
Magdalena
M
D000230:Adenocarcinoma; D017209:Apoptosis / Q000187:drug effects*; D053143:Caspase 2; D020169:Caspases / Q000378:metabolism*; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D006801:Humans; D007211:Indoles / Q000493:pharmacokinetics / Q000627:therapeutic use*; D054833:Isoindoles; D008175:Lung Neoplasms / Q000188:drug therapy* / Q000473:pathology; D015388:Organelles / Q000378:metabolism; D009942:Organometallic Compounds / Q000493:pharmacokinetics / Q000627:therapeutic use*; D010778:Photochemotherapy; D017319:Photosensitizing Agents / Q000627:therapeutic use; D017967:Zinc Compounds
D007211:Indoles; D054833:Isoindoles; D009942:Organometallic Compounds; D017319:Photosensitizing Agents; D017967:Zinc Compounds; C052159:Zn(II)-phthalocyanine; D053143:Caspase 2; D020169:Caspases