title: Ruthenium porphyrin-induced photodamage in bladder cancer cells.
abstract: Photodynamic therapy (PDT) is a noninvasive treatment for solid malignant and flat tumors. Light activated sensitizers catalyze photochemical reactions that produce reactive oxygen species which can cause cancer cell death. In this work we investigated the photophysical properties of the photosensitizer ruthenium(II) porphyrin (RuP), along with its PDT efficiency onto rat bladder cancer cells (AY27). Optical spectroscopy verified that RuP is capable to activate singlet oxygen via blue and red absorption bands and inter system crossing (ISC) to the triplet state. In vitro experiments on AY27 indicated increased photo-toxicity of RuP (20μM, 18h incubation) after cell illumination (at 435nm), as a function of blue light exposure. Cell survival fraction was significantly reduced to 14% after illumination of 20μM RuP with 15.6J/cm(2), whereas the "dark toxicity" of 20μM RuP was 17%. Structural and morphological changes of cells were observed, due to RuP accumulation, as well as light-dependent cell death was recorded by confocal microscopy. Flow cytometry verified that PDT-RuP (50μM) triggered significant photo-induced cellular destruction with a photoxicity of (93%±0.9%). Interestingly, the present investigation of RuP-PDT showed that the dominating mode of cell death is necrosis. RuP "dark toxicity" compared to the conventional chemotherapeutic drug cisplatin was higher, both evaluated by the MTT assay (24h). In conclusion, the present investigation shows that RuP with or without photoactivation induces cell death of bladder cancer cells.
authors: Department Molecular Biology of Cell Cycle, Institute of Molecular Biology, Bulgarian Academy of Sciences, Acad. "G. Bonchev" Str., Bl. 21, Sofia 1113, Bulgaria. Electronic address: vanya.bogoeva@gmail.com.
authors: Vanya
authors: V
authors: Bogoeva
authors: Department of Physics, Norwegian University of Science and Technology, N-7491 Trondheim, Norway.
authors: Monica
authors: M
authors: Siksjø
authors: Department of Physics, Norwegian University of Science and Technology, N-7491 Trondheim, Norway.
authors: Kristin G
authors: KG
authors: Sæterbø
authors: Department of Physics, Norwegian University of Science and Technology, N-7491 Trondheim, Norway.
authors: Thor Bernt
authors: TB
authors: Melø
authors: Department of Physics, Norwegian University of Science and Technology, N-7491 Trondheim, Norway.
authors: Astrid
authors: A
authors: Bjørkøy
authors: Department of Physics, Norwegian University of Science and Technology, N-7491 Trondheim, Norway; Department of Physics, Chemistry and Biology, Linköping University, SE-58183 Linköping, Sweden.
authors: Mikael
authors: M
authors: Lindgren
authors: Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology, N-7491 Trondheim, Norway.
authors: Odrun A
authors: OA
authors: Gederaas
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D002470:Cell Survival; D005434:Flow Cytometry; D018613:Microscopy, Confocal; D010778:Photochemotherapy; D011166:Porphyrins / Q000627:therapeutic use*; D051381:Rats; D012428:Ruthenium / Q000627:therapeutic use*; D001749:Urinary Bladder Neoplasms / Q000628:therapy*
chemical_list: D011166:Porphyrins; D012428:Ruthenium
keywords: Bladder cancer; PDT; Photodynamic therapy; Photophysical characterization; Ruthenium porphyrin; Singlet oxygen