BACKGROUND: High linear energy transfer (LET) radiation such as @entity505 ion particles is successfully used for treatment of solid @entity5 . The reason why high LET radiation accomplishes greater @entity5 -killing than X-rays is still not completely understood. One factor would be the clustered or complex-type DNA damages. We previously reported that complex DNA double-strand breaks produced by high LET radiation enhanced DNA end resection, and this could lead to higher kinase activity of @entity15126 protein recruited to RPA-coated single-stranded DNA. Although the effect of @entity15126 inhibition on cells exposed to low LET gamma-rays has recently been reported, little is known regarding the effect of @entity15126 inhibitor on cells treated with high LET radiation. The purpose of this study is to investigate the effects of the @entity15126 inhibitor @entity68099 in @entity1 @entity5 and normal cells irradiated with high LET @entity505 ions. FINDINGS: HeLa, @entity1 , and 1BR-hTERT (normal) cells were pre-treated with 1   M @entity68099 for 1 hour and irradiated with either high LET @entity505 ions or X-rays. Cell survival, cell cycle distribution, cell growth, and micronuclei formation were evaluated. @entity68099 caused abrogation of G2/M checkpoint and forced irradiated cells to divide into daughter cells. We also found that @entity505 ions caused a higher number of multiple micronuclei than X-rays, leading to decreased cell survival in @entity5 cells when treated with @entity68099 , while the survival of irradiated normal cells were not significantly affected by this inhibitor. CONCLUSIONS: @entity15126 inhibitor would be an effective @entity5 radiosensitizer with @entity505 ion irradiation.

@entity68099 , an @entity15126 inhibitor, causes radiosensitization in XXXX @entity5 cells irradiated with high LET radiation.

@entity1 :: ('9606', 'Species') :: ['U2OS', 'human'] @entity15126 :: ('545', 'Gene') :: ['ATR'] @entity5 :: ('MESH:D009369', 'Disease') :: ['tumor', 'tumors'] @entity68099 :: ('MESH:C560580', 'Chemical') :: ['VE-821'] @entity505 :: ('MESH:D002244', 'Chemical') :: ['carbon']
@entity1 :: (9606,Species) :: ['human']
