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Photodynamic activities
of benzochlorin and porphycene derivatives on nasopharyngeal carcinoma
cells
Mak, N1,
Lee, Y1, Leung, W1,
Huang, D2 and Chang, C3
Hong Kong Baptist University1
Chinese University of Hong Kong2
Hong Kong University of Science & Technology3
Abstract-
Nasopharyngeal carcinoma (NPC) is the third leading cause of cancer
deaths in Hong Kong. The purpose of this study was to evaluate the photocytotoxicity
of nine synthetic sensitizers, belonging to the families of benzochlorins
(BC) and porphycenes (PC), on two NPC cell lines. By comparing the LC50
of the photosensitizers, we found that the side chains of the compounds
determined the levels of toxicity on the CNE-2 and the HK-1 NPC cells.
One of the most potent compounds PS6A (PC-C6-Me3-I+) was selected in
this study. Uptake kinetics study indicates a steady increase in fluorescence
in the first 18 hours of incubation. Results from flow cytometric analysis
showed that over 99 % of CNE-2 NPC cells were strongly sensitized with
PS6A at 24 hours after drug treatment. At the light dose of 80 kJ/m2
(500 - 900nm), the LC50 of PS6A was 0.6 ug/ml for both CNE-2 and HK-1
NPC cells. Confocal microscopy revealed that PS6A was localized in the
cytoplasm of NPC cells. The results suggested that PS6A might be a candidate
in the photodynamic treatment of the NPC. Acknowledgement: This work
is supported by the Research Grants Council of Hong Kong, PRC. Project
no. CA99/00.SC02
Keywords: Nasopharyngeal
carcinoma, PDT, benzochlorins, porphycenes
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