Enhanced Susceptibility of Mouse Squamous Cell Carcinoma to Photodynamic Therapy Combined With Low-Dose Administration of Cisplatin
Purpose
We have investigated the antitumor effect of photodynamic therapy (PDT), using Photofrin as the photosensitizer, combined with low-dose cisplatin (CDDP) on NR-S1 mouse squamous cell carcinoma.
Materials and Methods
CDDP (5 mg/kg body weight) was injected intraperitoneally either 1 hour or 3 hours prior to PDT or immediately afterward. Twenty-four hours after each protocol, the antitumor effects were evaluated by percentage area of the tumor necrosis in hematoxylin-eosin stained specimens as well as terminal deoxynucleotidyl transferase-mediated d-UTP nick-end labeling indices. Furthermore, the tumor sizes were evaluated at 3, 7, and 10 days after each protocol.
Results
The antitumor effect of PDT was enhanced by administration of CDDP 3 hours before PDT, whereas the administration of CDDP 1 hour before PDT or immediately after PDT did not potentiate a PDT antitumor effect.
Conclusion
Administration of low-dose CDDP 3 hours before PDT appears to be a useful treatment modality.
Address correspondence and reprint requests to Dr Uehara: Division of Oral and Maxillofacial Surgical Reconstruction and Restoration, Department of Developmental and Reconstructive Medicine, Graduate School of Biomedical Sciences, Nagasaki University, 1-7-1 Sakamoto, Nagasaki 852-8588, Japan
Received from the Division of Oral and Maxillofacial Surgical Reconstruction and Restoration, Department of Developmental and Reconstructive Medicine, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan
ABSTRACT