Assessment of cellular damage by comet assay after photodynamic therapy in vitro.
The aim of this study was analysis of DNA damage in the cell line of the human melanoma G361 after photodynamic therapy (PDT) by comet assay. Photodynamic therapy is based on cytotoxic action of sensitizers (10 microM ZnTPPS4 fixed into 1 mM cyclodextrin hpbetaCD) and light with a suitable wavelength. Single-cell gel electrophoresis (SCGE, comet assay) is a rapid and sensitive method for detecting DNA strand breaks at the level of single cells. Great amount of DNA damage was detected with the dose of irradiation of 0.1; 0.5 J and 2.5 J x cm(-2). Only radiation dose of visible light in the presence of sensitizers can induce DNA breaks of tumour cells. Cells with DNA damage appear as fluorescent comets with tails of DNA fragmentation. In contrast, cells with undamage DNA appear as round spots, because their intact DNA does not migrate out of the cell.
Macecek
Jaroslav
J
Palacky University in Olomouc, Department of Medical Biophysics, Faculty of Medicine, Czech Republic. macecele@tunw.upol.cz
Kolárová
Hana
H
Psotová
Jitka
J
Bajgar
Robert
R
Huf
Martin
M
Nevrelová
Pavla
P
Tomeeka
Marek
M
Mosinger
Jirí
J
D045744:Cell Line, Tumor / Q000187:drug effects; D020552:Comet Assay; D004249:DNA Damage; D004273:DNA, Neoplasm / Q000187:drug effects* / Q000528:radiation effects; D006801:Humans; D066298:In Vitro Techniques; D008546:Melanoma, Experimental / Q000188:drug therapy*; D010778:Photochemotherapy; D012878:Skin Neoplasms / Q000188:drug therapy*
D004273:DNA, Neoplasm