期刊名称：Journal of Clinical Biochemistry and Nutrition
印刷版ISSN：0912-0009
电子版ISSN：1880-5086
出版年度：1996
卷号：21
期号：1
页码：29-37
DOI：10.3164/jcbn.21.29
出版社：The Society for Free Radical Research Japan
摘要：The mode of cell death in transplanted human cancer tissue following photodynamic therapy (PDT) was investigated from the perspective of apoptosis. Human pancreatic carcinoma transplanted into nude mice was treated by PDT following sensitization with Photofrin. PDT treatment showed significant therapeutic effects at 7 days post treatment as compared with laser irradiation treatment only at each laser energy dose when the mean of each overall split surface of the necrotic area was measured. The characteristic DNA ladder formation indicative of apoptosis was demonstrated 2h after PDT treatment in every group of PDT treatment regardless of the laser energy such as 25, 50, or 100J/cm2. However, no evidence of DNA ladder formation was found in the groups of laser irradiation only. Intense TUNEL signals were demonstrated in nuclei of tumor cells 2h after PDT treatment. In tumor tissues 7 days after PDT treatment, TUNEL signals were also recognized in the peripheral tumor cells close to the necrotic area. On the other hand, tumor cells with TUNEL signals could not be found in the untreated control group or in groups given only laser irradiation either 2h or 7 days after the irradiation. The observation that solid tumors treated by PDT undergo apoptosis implies that cell death in response to PDT is not only a passive phenomenon resulting from massive membrane damage, but is also one that requires the participation of cell metabolism, suggesting new possibilities of modifying the cell death program by modulation with cytokines, growth factors, and certain genes that control apoptosis.
