Photosensitisation of a murine mammary adenocarcinoma with Verteporfin

CASAS A, DI VENOSA G, BATLLE A, FUKUDA H

Leeds, Inglaterra

Workshop; Tetrapyrrole Discussion Group; 2003

Tetrapyrrole Discussion Group

Benzoporphyrin derivative monoacid ring A (BPD-MA) is a second generation hydrophobic photosensitizer for PDT that has been appoved for ocular disease treatment. In that work we report the results of in vivo studies on the photosensitising activity of Verteporfin by LM3 cells, reaching maxima concentration after 5 h exposure to 18 mg Verteporfin/ml. Independently on the concentration, plateaux levels are attained 5 h after exposure to Verteporfin. Exposure of the cells to the photosensitiser appears to be safe in the darkness within a broad range of concentrations. The hydroxyl radical scavenger mannitol, affored the highest protection against PDT, while L-tryptophan, as well known and efficient singlet oxygen quencher was not an effective protector at all, showing scavengering activity only when it was supplemented at concentration as high as 10 mM and when 50% of the cells were affected, showing that in addition to single oxygen, which is considered the primary cytotoxic agent in PDT, other interconvertible reactive oxygen specie, in particular HO are also generated. Verteporfin-PDT, also induced morphological features typical of apoptotic cells. Results show that the LM3 adenocarcinoma cell can be effectively sensitized with Verteporfin-PDT.