18 January 2008 mTHPC-photodynamic therapy induced apoptosis in nasopharyngeal carcinoma cells
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In this study, the early apoptotic events of mTHPC-medicated photodynamic therapy (PDT) was explored in two human nasopharyngeal carcinoma (NPC) cell lines - NPC/HK1 cells and NPC/CNE2 cells. Cells (5 x 103) were incubated with mTHPC (0.8 μg/ml) in chamber slides for 20 h and subjected to light irradiation at 2 J/cm2 (LD80). Morphologic changes of treated cells were examined at 0- 4 h after the light irradiation by a light microscopy. The early stage of apoptosis was detected by fluorescein-conjugated Annexin V (Annexin V-FITC) assay. Mitochondrial membrane damage and cytochrome c release were determined by flowcytometric analysis. The Bcl-2 expression was measured by Western blot analysis. One hour after mTHPC-mediated PDT, membrane blebbing and cell shrinkage appeared in both HK1 and CNE2 cells. Annexin V-FITC assay showed that a considerable number of HK1 and CNE2 cells became apoptotic at 1 h after PDT. Flowcytometric analysis showed that the cytochrome c was released at 1 h after PDT. The Bcl-2 expression also declined significantly in both cell lines compared to the control groups. mTHPC-mediated PDT can effectively induce apoptotic responses in NPC cells which might be modulated by mitochondrial damage and Bcl-2 inhibition.
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Christine M. N. Yow, Albert W. N. Leung, Zheng Huang, "mTHPC-photodynamic therapy induced apoptosis in nasopharyngeal carcinoma cells", Proc. SPIE 6826, Optics in Health Care and Biomedical Optics III, 68261P (18 January 2008); doi: 10.1117/12.756807; https://doi.org/10.1117/12.756807

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