TY - JOUR T1 - Radiosensitizing Effect of 5-Aminolevulinic Acid and Protoporphyrin IX on Carbon-ion Beam Irradiation JF - Anticancer Research JO - Anticancer Res SP - 4313 LP - 4317 DO - 10.21873/anticanres.12730 VL - 38 IS - 7 AU - TOMOKO KANEKO AU - MASAHIDE TOMINAGA AU - RISA KOUZAKI AU - AYAKA HANYU AU - KAZUKI UESHIMA AU - HISATSUGU YAMADA AU - MASAKI SUGA AU - TOMOHIRO YAMASHITA AU - TOMOAKI OKIMOTO AU - YOSHIHIRO UTO Y1 - 2018/07/01 UR - http://ar.iiarjournals.org/content/38/7/4313.abstract N2 - Background/Aim: Carbon-ion beam is one of the most advanced radiations used for cancer treatment. However, there are tumors that are difficult to suppress with carbon-ion beam alone, thus necessitating development of drugs that can enhance its therapeutic effect. In this regard, the radiosensitizing effect of 5-aminolevulinic acid (ALA) and protoporphyrin IX (PpIX), that is a metabolic intermediate of ALA, on carbon-ion beam was investigated. Materials and Methods: Radiosensitizing activity, mitochondrial ROS and DNA double-strand break production of ALA and PpIX were evaluated by irradiation with 1.0 or 1.5-Gy carbon-ion beam to mouse mammary EMT6 tumor cells. Results: Combination of carbon-ion beam and ALA or PpIX showed a significant enhancement of its cytotoxic activity through a significant increase in ROS production in mitochondria. Furthermore, the combined activity of carbon-ion beam and ALA resulted in a significant increase in DNA double-strand breakage. Conclusion: ALA selectively accumulates in the mitochondria and PpIX synthesized from ALA reacts with carbon-ion beam to produce ROS that exert antitumor activity. ER -