2007 Fiscal Year Final Research Report Summary

Antitumor effect of acridine orange under ultrasonic irradiation in vitro

Research Project

Project/Area Number	18591621
Research Category	Grant-in-Aid for Scientific Research (C)
Allocation Type	Single-year Grants
Section	一般
Research Field	Orthopaedic surgery
Research Institution	Akita University
Principal Investigator	OKADA Kyoji Akita University, School of Medicine, Associate professor (10185431)
Project Period (FY)	2006 – 2007
Keywords	Acridine orange / Ultrasound / Sarcoma
Research Abstract	Background: Sonodynamic synergistic antitumor therapy is a promising new methodology for cancer treatment. Materials and Methods: To determine the antitumor effects of ultrasound (US) in the presence of acridine orange (AO), 1.0 μg/ml solution of AO was tested as a sonodynamic compound against sarcoma 180 cells in vitro. Results: After US irradiation at 2.0 W/cm^2 for 60 sec, the survival rate of tumor cells in the presence of AO was significantly lower than in its absence (p<0.001). In the AO-treated group, the tumor cells were mostly fragmented. When D-mannitol or L-histidine was used along with the AO, the survival rate of tumor cells after irradiation was significantly higher than that when AO alone was applied. Conclusion: AO could exhibit useful antitumor activity under US irradiation, and the generation of singlet oxygen and hydroxyl radicals is involved in the processes of tumor cell damage.