A novel photodynamic therapy for drug-resistant prostate cancer cells using porphyrus envelope as a novel photosensitizer.

Background: In the clinic, it is often very difficult to treat drug-resistant advanced prostate cancer by conventional treatments. Photodynamic therapy (PDT) is a minimally invasive treatment that takes advantage of photochemical reactions between a photosensitizer and light. On the basis of several of its key characteristics, PDT is considered to be a promising novel method for treating drug-resistant prostate cancer.

Objective: For effective treatment of drug-resistant prostate cancer, we developed a novel agent termed porphyrus envelope, which was produced from PpIX lipid and hemagglutinating virus of Japan envelope (HVJ-E).

Methods: We inserted PpIX lipid into HVJ-E by centrifugation, and used the resultant porphyrus envelope in PDT of two drug-resistant prostate cancer cell lines, PC-3 and PC-3-DR.

Results: Porphyrus envelope enhanced uptake of PpIX, and cytotoxicity of PDT, relative to free PpIX lipid or PpIX induced by 5-ALA.

Conclusions: PDT using porphyrus envelope has potential as a method for treating drug-resistant prostate cancer.