title: Enhancing radiosensitivity of TE1, TE8, and TE 11 esophageal squamous carcinoma cell lines by Hdm2-siRNA targeted gene therapy in vitro.
abstract: BACKGROUND
  Human double minute2 (hdm2) level increases in most human malignancies. Therefore, inhibition of tumor growth and also induction of radiosensitivity may be provided by hdm2 inhibitors. The effects of hdm2-siRNA on hdm2 protein expression, cell apoptosis rate, and radiosensitivity of human esophageal squamous cell carcinoma (ESCC) were studied.
  
  
  METHODS
  The hdm2 gene was silenced in TE1, TE8, and TE11 ESCC cell lines using 200nM siRNA by liposomal transfection method followed by irradiation with 0.5, 1, 2, 4, and 6 Gy γ-rays in vitro. The gene expression levels were evaluated by real time PCR and Western Blotting methods. MTT, TUNEL, and also colony forming assays were used to compare the radiosensitivity of the cell lines before and after the treatments.
  
  
  RESULTS
  Hdm2-siRNA reduced the hdm2 protein as compared to the vehicle control and scrambled groups, and also increased the radiation-induced apoptosis especially in TE11 cells. The related dose reduction factors (DRFs) for the silenced TE1, TE8, and TE11 cells calculated to be 1.20, 1.30, and 2.75, respectively.
  
  
  CONCLUSIONS
  Increasing radiosensitivity of tumor cells may be provided by silencing the oncogenes.
authors.affiliation: Department of Medical Physics, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran.
authors.forename: Jalil
authors.initials: J
authors.lastname: Pirayesh Islamian
authors.affiliation: Department of Medical Radiation Science, School of Paramedicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Mohsen
authors.initials: M
authors.lastname: Mohammadi
authors.affiliation: Immunology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.
authors.forename: Behzad
authors.initials: B
authors.lastname: Baradaran
authors.affiliation: Department of Medical Physics, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran.
authors.forename: Alireza
authors.initials: A
authors.lastname: Farajollahi
authors.affiliation: Department of Radiation Medicine, Faculty of Nuclear Engineering, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Seyed Mahmoud Reza
authors.initials: SM
authors.lastname: Aghamiri
authors.affiliation: Department of Statistics and Epidemiology, Tabriz University of Medical Sciences, Tabriz, Iran.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Asghari Jafarabadi
authors.affiliation: Department of Biotechnology, Faculty of Medicine, Arak University of Medical Sciences, Arak, Iran.
authors.forename: Hadi
authors.initials: H
authors.lastname: Karami
authors.affiliation: Department of Hematology, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran.
authors.forename: Amir
authors.initials: A
authors.lastname: Monfaredan
authors.affiliation: Immunology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.
authors.forename: Dariush
authors.initials: D
authors.lastname: Shanehbandi
keywords: Cell line; Esophagus cancer; Hdm2-siRNA; Oncogene; Radiosensitivity; Squamous cell carcinoma