Author/Authors :
Kaneko, T. Tokushima University - Graduate School, Institute of Technology and Science - Department of Life System, Japan , Tominaga, M. Tokushima University - Graduate School, Institute of Health Biosciences - Department of Radiological Science, Japan , Endo, H. Tokushima University - Graduate School, Institute of Technology and Science - Department of Life System, Japan , Yaju, K. Tokushima University - Graduate School, Institute of Technology and Science - Department of Life System, Japan , Kouzaki, R. Tokushima University - Graduate School, Institute of Technology and Science - Department of Life System, Japan , Yamada, H. Tokushima University - Graduate School, Institute of Technology and Science - Department of Life System, Japan , Nakanishi, I. National Institute of Radiological Sciences - Research Center for Charged Particle Therapy - Advanced Particle Radiation Biology Research Program, Radio-Redox-Response Research Team, Japan , Matsumoto, K. National Institute of Radiological Sciences - Research Center for Charged Particle Therapy - Advanced Particle RadiationBiology Research Program, Radio-Redox-Response Research Team, Japan , Uto, Y. Tokushima University - Graduate School, Institute of Technology and Science - Department of Life System, Japan
Abstract :
5-Aminolevulinic acid (ALA), a precursor of protoporphyrin IX (PpIX), has been utilized as a potent sensitizer for photodynamic therapy (PDT) of cancer through production of reactive oxygen species (ROS). ALA also has been proposed as a possible radiosensitizer with low linear energy transfer (LET) radiation because antitumor activity of low-LET radiation depends on ROS mainly. In this paper, we investigated the radiosensitizing activity of PpIX in carbon ion irradiation as a high LET radiation. PpIX was detected in an EMT6 mouse mammary breast tumor cells even at 24 h post treatment. The cytotoxicity of PpIX against EMT6 cells was IC50 = 48.0 μm. The combined treatment of 1.0 μm of PpIX with 2 Gy of carbon ion irradiation (290 MeV/nucleon, 85.1 keV/μm) showed a more potent antitumor activity than carbon ion irradiation alone. We demonstrated that PpIX showed a radiosensitizing effect with carbon ion beam against mouse mammary breast tumor cells.
Keywords :
Carbon Ion Beam , Protoporphyrin IX , Aminolevulinic Acid , Radiosensitization
