PU-H71, a novel Hsp90 inhibitor, as a potential cancer-specific sensitizer to carbon-ion beam therapy. (30th September 2016)

• Record Type: Journal Article
• Authors: Li, Huizi Keiko; Matsumoto, Yoshitaka; Furusawa, Yoshiya; Kamada, Tadashi
• Is Part Of: Journal of radiation research. Volume 57:Number 5(2016:Sep.)
• Page Start: 572
• Page End: 575
• Publication Date: 2016-09-30
• Subjects: PU-H71 -- Hsp90 -- carbon ion -- radiosensitizer; Radiology, Medical -- Periodicals; Radiobiology -- Periodicals; Radiation -- Periodicals; 616.0757
• DOI: 10.1093/jrr/rrw054
• Languages: English
• ISSNs: 0449-3060

Abstract

Abstract: PU-H71, a heat shock protein 90 (Hsp90) inhibitor, has yielded therapeutic efficacy in many preclinical models and is currently in clinical trials. Carbon-ion radiotherapy (CIRT) has provided successful tumor control; however, there is still room for improvement, particularly in terms of tumor-specific radiosensitization. The Hsp90 inhibitor PU-H71 has been shown to sensitize tumor cells to X-ray radiation. A murine osteosarcoma cell line (LM8) and a normal human fibroblast cell line (AG01522) were treated with PU-H71 before X-ray, 14- or 50-keV/µm carbon-ion beam (C-ion) irradiation. Cell survival and protein expression were evaluated with colony formation and western blot, respectively. Treatment with PU-H71 alone was shown to be non-toxic to both cell lines; however, PU-H71 was shown to significantly sensitize LM8 cells to not only X-ray, but also to C-ion irradiation, while only a minimal sensitizing effect was observed in AG01522 cells. PU-H71 treatment was found to suppress the protein expression levels of Rad51 and Ku70, which are associated with the homologous recombination pathway and the non-homologous end-joining pathway of double-strand break repair. The findings reported here suggest that PU-H71 could be a promising radiosensitizer for CIRT.