Endoplasmic reticulum and Golgi apparatus are the preferential sites of Foscan localisation in cultured tumour cells.
Intracellular photosensitiser localisation significantly influences the mechanism of response to photodynamic therapy (PDT), since the primary sites of damage are closely related to the specific sensitiser distribution. Foscan subcellular localisation in the MCF-7 human adenocarcinoma cell line has been studied by means of confocal microscopy and microspectrofluorometry. The fluorescence topographic profiles recorded after cells costained with Foscan and organelle-specific fluorescent probes revealed that Foscan presents low localisation in lysosomes and a weak accumulation in mitochondria. Alternatively, the Foscan fluorescence topographic profile turned out to colocalise perfectly with that obtained for the endoplasmic reticulum (ER) and the Golgi apparatus. The patterns of fluorescence derived from confocal microscopy studies were consistent with predominant localisation of Foscan in these organelles. Furthermore, evaluation of enzymatic activity of selected organelles immediately after laser light irradiation (650 nm) indicated the Golgi apparatus and ER as the primary damaged sites resulting from Foscan-mediated PDT in the MCF-7 cell line. To our knowledge, this is the first study to demonstrate unambiguously that the ER and the Golgi apparatus are preferential sites of Foscan accumulation.
Teiten
M-H
MH
Unité de Recherche en Thérapie Photodynamique, Centre Alexis Vautrin, F-54511 Vandoeuvre-les-Nancy Cedex, France.
Bezdetnaya
L
L
Morlière
P
P
Santus
R
R
Guillemin
F
F
D000970:Antineoplastic Agents / Q000493:pharmacokinetics*; D004721:Endoplasmic Reticulum / Q000378:metabolism*; D006056:Golgi Apparatus / Q000378:metabolism*; D006801:Humans; D008652:Mesoporphyrins / Q000493:pharmacokinetics*; D018613:Microscopy, Confocal; D010777:Photochemistry; D013050:Spectrometry, Fluorescence; D013347:Subcellular Fractions; D014407:Tumor Cells, Cultured
D000970:Antineoplastic Agents; D008652:Mesoporphyrins; C072269:temoporfin