Photodynamic therapy for human oral squamous cell carcinoma and xenografts using a new photosensitizer, PAD-S31

✍ Scribed by Masataka Date; Isao Sakata; Kazuhide Fukuchi; Kiyoshi Ohura; Yasutaka Azuma; Mitsuko Shinohara; Koichi Matsuzaki; Yoshihisa Namiki; Hiroshi Takahashi

• Publisher: John Wiley and Sons
• Year: 2003
• Tongue: English
• Weight: 236 KB
• Volume: 33
• Category: Article
• ISSN: 0196-8092
• DOI: 10.1002/lsm.10188

✦ Synopsis

Abstract

Background and Objectives

Photodynamic therapy (PDT) is a novel and promising cancer treatment that employs a combination of photosensitizer and visible light. We examined the effect of PDT using a new photosensitizer, PAD‐S31, and the 670‐nm diode laser in human oral squamous cell carcinomas (SCC).

Study Design/Materials and Methods

SAS and HSC‐4 cell lines were used in all the experiments. Cell viability was determined by a modified MTT assay. Two methods were used for the determination of apoptosis in human oral SCC cells: TUNEL assay and detection of fragmented mono‐ and oligo‐nucleosomes by ELISA. Xenografts of human oral SCC cells were generated in KSN S1c nude mice.

Results

In vitro PDT using PAD‐S31 and the 670‐nm diode laser showed cytotoxicity that was a function of laser energy, drug concentration, and time to the SAS and HSC‐4 cell lines. On the other hand, PAD‐S31 without irradiation had no effect on cell viability. The combinated use of PAD‐S31 and the laser irradiation showed excellent anti‐tumor activity against tumor xenografts without severe side effects. PDT‐mediated cell death occurred predominantly by apoptosis in vitro and in vivo.

Conclusions

The present study demonstrates that PAD‐S31 may serve as a potent photosensitizer for PDT. Furthermore, it is expected that this therapy will be clinically useful for the treatment of patients with oral carcinoma. Lasers Surg. Med. 33:57–63, 2003. © 2003 Wiley‐Liss, Inc.