title: A histone deacetylase inhibitor, trichostatin A, enhances radiosensitivity by abrogating G2/M arrest in human carcinoma cells.
abstract: OBJECTIVE
  Histone deacetylase inhibitors (HDIs) are emerging as potentially useful components in anticancer therapy. In this study, we tried to confirm the radiosensitizing effect of trichostatin A (TSA) on a panel of human carcinoma cell lines and elucidate its mechanism of interaction.
  
  
  METHODS
  A549, HeLa and Caski cells were exposed to TSA for 18 hr prior to irradiation, and the cell survival then measured using a clonogenic assay. Western blot and flow cytometric analyses, for histone acetylation, and cell cycle and apoptosis, respectively, were also performed.
  
  
  RESULTS
  TSA increased the acetylation of histone H3. The pretreatment of TSA consistently radiosensitized all three cell lines. The SF2 (surviving fraction at 2 Gy) of TSA-treated cells was significantly lower than that of mock treated cells. The SER (sensitizer enhancement ratio) increased in all 3 cell lines, in concentration dependent manners. The TSA treated cells showed abrogation of radiation-induced G2/M arrest, in a concentration dependent manner.
  
  
  CONCLUSIONS
  The pretreatment of TSA enhanced the radiosensitivity of a panel of human carcinoma cells, which was attributed, in part, to the abrogation of radiation-induced G2/M arrest.
authors: Department of Radiation Oncology, Seoul National University College of Medicine, Seoul, Korea.
authors: In Ah
authors: IA
authors: Kim
authors: Jin Ho
authors: JH
authors: Kim
authors: Jin Hee
authors: JH
authors: Shin
authors: Il Han
authors: IH
authors: Kim
authors: Jae Sung
authors: JS
authors: Kim
authors: Hong-Gyun
authors: HG
authors: Wu
authors: Eui Kyu
authors: EK
authors: Chie
authors: Yong Ho
authors: YH
authors: Kim
authors: Bo-Kyung
authors: BK
authors: Kim
authors: Semie
authors: S
authors: Hong
authors: Seok Won
authors: SW
authors: Park
authors: Sung Whan
authors: SW
authors: Ha
authors: Charn Il
authors: CI
authors: Park