吖啶橙經藍光照射後產生光毒性阻殺人類膀胱癌細胞
林宜佳1#、林致凡2#、蔡德甫1、陳宏恩1、仇光宇1、黃一勝1,3,4
1新光醫院外科部泌尿科、2新光醫院中央研究室、3台北醫學大學醫學院、4輔仁大學醫學院
Acridine orange exhibits phototoxicity against human bladder cancer cells under blue light exposure
Yi-Chia Lin1, Ji-Fan Lin2, Te-Fu Tsai 1,4, Hung-En Chen1, Kuang-Yu Chou1,4, and
Thomas I-Sheng Hwang1,3,4
1Department of Urology, Shin Kong Wu Ho-Su Memorial Hospital, 2Central Laboratory, Shin Kong Wu Ho-Su Memorial Hospital, 3Department of Urology, Taipei Medical University, 4Division of Urology, School of Medicine, Fu-Jen Catholic University, Taipei, Taiwan.
Background: Human bladder cancer (BC) cells exhibited a high basal level of autophagic activity demonstrated by accumulating of acridine orange (AO)-stained acidic vesicular organelles(AVOs) in BC cells. In this study, we aim to investigate the cytotoxicity effects of AO on the human BC cell lines under blue-light exposure.
Materials and methods: To evaluate phtotoxicities of AO toward human bladder cancer cells,we designed and developed a blue-light source equipped with 6 blue-light LED (peak wavelength: 443.7 nm). The AO relocalization in treated-BC cells was recorded using a fluorescence microscopy equipped with a color CCD camerain a real-time fashion. The cell viability was determined using (a) WST-1 reagents (immediately after treatment for 1 hour), (b) continuous quantification with Cytation 5 Cell Imaging Multi-mode reader (Biotek Instruments, Inc., for 24 hours), and (c) time-lapse imaging with a cell imaging recorder (Cytosmart System, Lonza; for 36 hours) in human immortalized uroepithelial (SV-Huc1) and BC cell lines (5637 and T24) treated with indicated concentration of AO with or without blue light exposure.
Results:TheAO relocation was clearly monitored by fluorescent microscopy with decreased red fluorescent intensity over exposure duration within 5-15 secounds in BC cells. Treatment ofAO or blue-light exposure alone did not cause a significant decrease of cell viability in BC cells. However, we found that AO exhibited a dose-dependent increment of cytotoxicity toward BC cells with blue-light exposure (AO-PDT). In addition, this phenomenon was more prominent in human BC cell lines compared to SV-Huc1 cells. These results suggested that AO, as a photosensitizer, disrupts acidic organelles in BC cells under blue light irradiation in BC cells.
Conclusion:Blue light irradiation in BC cell treated with AO causes severe cell death. The photodynamic effect can be applied clinically to an existing instrument, namely narrow band image endoscopic system, to deliver blue light. The AO-PDT may serve as a novel therapeutic strategy to reduce recurrence or against human bladder cancer in the future.