RT Journal Article SR Electronic T1 Radiosensitizing Effect of 5-Aminolevulinic Acid and Protoporphyrin IX on Carbon-ion Beam Irradiation JF Anticancer Research JO Anticancer Res FD International Institute of Anticancer Research SP 4313 OP 4317 DO 10.21873/anticanres.12730 VO 38 IS 7 A1 TOMOKO KANEKO A1 MASAHIDE TOMINAGA A1 RISA KOUZAKI A1 AYAKA HANYU A1 KAZUKI UESHIMA A1 HISATSUGU YAMADA A1 MASAKI SUGA A1 TOMOHIRO YAMASHITA A1 TOMOAKI OKIMOTO A1 YOSHIHIRO UTO YR 2018 UL http://ar.iiarjournals.org/content/38/7/4313.abstract AB 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.