A novel ATX-S10(Na) photodynamic therapy for human skin tumors and benign hyperproliferative skin.

Background/purpose: Photodynamic therapy (PDT) is a promising treatment for various skin tumors and other skin diseases. We investigated the potential therapeutic effects of PDT using ATX-S10(Na) ointment and a diode laser in mouse skin models of experimental skin tumors as well as transplanted human samples of superficial skin tumors and lesional psoriatic skin. Methods: ATX-S10(Na) ointment (1% w/v) was introduced into tape-stripped mouse skin, transplanted squamous cell carcinoma (SCC) samples and human skin diseases after topical application, then PDT was performed. Results: ATX-S10(Na) ointment (1% w/v) was introduced effectively into tape-stripped mouse skin and transplanted SCC samples after topical application, but was not detected after 48 h, as assessed by fluorescence microscopy. PDT, using 1% ATX-S10(Na) ointment and diode laser (50 J/cm2), was found to decrease epidermal thickness in 12-0-tetradecanoylphorbol-13-acetate (TPA)-treated mouse skin by 6 days. PDT with 1% ATX-S10(Na) ointment and diode laser (150 J/cm2) was also effective for transplanted SCC, and tumors were eliminated by 6 weeks. PDT against Bowen disease, basal-cell carcinoma, and psoriasis xenografts onto SCID mice also showed marked suppression of tumor growth and cell proliferation, respectively. Conclusion: Our results indicate that ATX-S10(Na)-PDT is an effective treatment for various skin tumors and psoriasis in experimental mouse models.