Radiation therapy is one of the most promising therapeutic strategies in unresectable @entity1721 ( @entity1721 ). The histone deacetylase (HDAC) inhibitor has been shown to enhance radiosensitivity. @entity1092 ( @entity3262 ) is a well-known drug used to treat @entity302 and @entity302 , and has been shown to inhibit HDACs. We recently reported that a clinically safe dose of @entity3262 enhances radiation  -induced @entity137 in @entity1 @entity1721 cells. However, the mechanism of radiosensitizing effect of @entity3262 has not yet been confirmed. The present study examined the effect of @entity3262 on DNA double-strand break (DSB) repair after radiation in the @entity1 @entity1721 cell lines KES, TE9 and TE11 by examining @entity6714 phosphorylation (yH2AX) levels as a marker of radiation  -induced DSBs. The present study also examined whether @entity3262 inhibited radiation-induced DNA DSB repair by suppressing non-homologous end joining (NHEJ), focusing particularly on the acetylation of @entity10320 . @entity3262 was shown to prolong yH2AX levels after irradiation in all three @entity1721 cell lines. Moreover, prolonged yH2AX foci formation after irradiation was also observed by immunocytochemistry following @entity3262 pretreatment in KES and TE9 cells. @entity3262 was shown to induce @entity10320 acetylation after irradiation in all three @entity1721 cell lines. Our results suggest that @entity3262 prolonged radiation  -induced DSBs by inhibiting NHEJ in DSB repair pathways in @entity1721 . @entity3262 could therefore be used as an effective radiosensitizer in @entity1721 radiotherapy.

Inhibitory effects of XXXX in DNA double-strand break repair after irradiation in esophageal squamous carcinoma cells.

@entity1 :: ('9606', 'Species') :: ['human'] @entity137 :: ('MESH:D064420', 'Disease') :: ['cytotoxicity'] @entity3262 :: ('D014635', 'Chemical') :: ['VPA'] @entity1092 :: ('MESH:D014635', 'Chemical') :: ['Valproic acid'] @entity1721 :: ('MESH:C562729', 'Disease') :: ['ESCC', 'esophageal squamous cell carcinoma'] @entity10320 :: ('2547', 'Gene') :: ['Ku70'] @entity302 :: ('MESH:D004827', 'Disease') :: ['seizure disorders', 'epilepsy'] @entity6714 :: ('3014', 'Gene') :: ['H2AX']
@entity1092 :: (MESH:D014635,Chemical) :: ['valproic acid']
