@misc{oai:repo.qst.go.jp:00070929,
 author = {Okayasu, Ryuichi and Hirakawa, Hirokazu and Noguchi, Miho and Hirayama, Ryoichi and Takahashi, Momoko and Fujimori, Akira and 岡安 隆一 and 平川 博一 and 野口 実穂 and 平山 亮一 and 高橋 桃子 and 藤森 亮},
 month = {Oct},
 note = {Due to its high relative biological effectiveness (RBE), heavy ion beams are thought to cause sufficient cellular damage to effectively kill cancer cells. However, even with high linear energy transfer (LET) heavy ion treatment, it may not be able to control all the tumor growth, and recurrence or metastasis might still occur. One strategy to cope with this situation is to combine heavy ion therapy with a chemical which further enhances biological effectiveness for tumor cell killing.  We have studied the combination effect of carbon ions and hsp90 inhibitors in vitro and in vivo. SQ5 lung tumor cells were used to examine cell survival by colony formation assay and also used for mouse xenograft model. Our data indicate that tumor growth was better controlled both in vitro and in vivo with the combination of hsp90 inhibitor 17AAG and carbon ions than the carbon treatment alone. Since 17AAG was previously shown to inhibit the homologous recombination repair (HRR) pathway of DNA double strand breaks (DSBs) in cells exposed to X-rays, HRR was also thought to be affected in cells irradiated with carbon ions. As our preliminary data indicated that this might be the case as DSB rejoining after carbon ion exposure was less efficient with 17AAG pretreatment. We are further studying the mechanism of hsp 90 radiosensitization with heavy ions as well as the effect of other hsp 90 inhibitors if they reveal the similar effect when combined with heavy ions., Radiation Research Society 58th Annual Meeting},
 title = {Hsp90 inhibitor may enhance the effectiveness of heavy ion treatment},
 year = {2012}
}