Photogem Induces Necrosis in Various Uterine Cervical Cancer Cell Lines by PDT

Abstract

Purpose: In order to elucidate the antitumor effect of photodynamic therapy (PDT), using a derivative of the photosensitizing agent hematoporphyrin (Photogem) and a diode laser, the cell death of uterine cancer cell lines (CaSki, HT3, HeLa, and SKOV-3), and mice transplanted with TC-1 lung cancer cells, were evaluated. Materials and Methods: The morphological changes, MTT assay, flow cytometry, cytotoxicity and tumor growth inhibition study were evaluated at various time intervals after the PDT. Results: The results showed that the survival rates of each cell line decreased with time and dose response after performing the PDT. Also, the PDT-induced damage of cancer cells was almost entirely confined to necrosis of the tumor cells in the early time courses. The irradiation of CaSki cells in the presence of Photogem induced plasma membrane disruption and cell shrinkage, indicating the plasma membrane as the main target for Photogem. In the in vivo experiment, significantly longer survival and a significantly smaller tumor size were seen over the time courses of the Photogem with irradiation compared to the untreated control groups; resorption of the tumor was also observed after the PDT treatment. Conclusion: Collectively, our results indicated that Photogem possesses anti-tumor effects, and necrosis- like death, with plasma membrane damage, was postulated to be the principal mechanism of the antitumor effect of the PDT using Photogem. (Cancer Res Treat. 2003;35:549-556)