title: The radiosensitization effects of Endostar on human lung squamous cancer cells H-520.
abstract: BACKGROUND
  The present study mainly aimed to investigate the direct effects of Endostar (ES) on the proliferation and radiosensitivity of human lung squamous cancer cell line H-520.
  
  
  RESULTS
  ES significantly inhibited H-520 cell proliferation in a time- and dose-dependent manner. According to the colony-forming assays, ES could increase the H-520 cell radiosensitivity. ES induced cell apoptosis, the apoptosis rate increased with the raise of ES concentration. Irradiation induced significantly higher apoptosis rate in ES-treated H-520 cells than non-treated H-520 cells. ES induced cell cycle distribution and G0/G1 arrest in H-520 cells, whereas irradiation induced G2/M arrest. The phospho-p38-MAPK and p-Akt protein levels were decreased in H-520 cells after ES treatment. Furthermore, activated caspase protein level increased and Bcl-2 protein levels decreased after treatment with ES and irradiation.
  
  
  CONCLUSIONS
  ES significantly enhanced the sensitivity of H-520 cells to irradiation by inhibition of cellular proliferation, promotion of cell apoptosis and redistribution of cell cycle, possibly via deactivation of Akt pathway. The present study supports the possibility to use the combination of ES and ionizing irradiation to treat patients with lung squamous cell cancer in clinics.
authors.affiliation: Cancer Center, Department of Radiation Oncology, Peking University Third Hospital, Beijing 100191, China. doctorwangjunjie@yahoo.com.cn.
authors.forename: Zhen Y
authors.initials: ZY
authors.lastname: You
authors.forename: Yong
authors.initials: Y
authors.lastname: Zhao
authors.forename: Feng
authors.initials: F
authors.lastname: Liu
authors.forename: Ying D
authors.initials: YD
authors.lastname: Zhang
authors.forename: Jun J
authors.initials: JJ
authors.lastname: Wang