title: [Effects of tetrandrine on enhancing radiosensitivity of human nasopharyngeal carcinoma cells].
abstract: OBJECTIVE
  To study the effect and mechanism of tetrandrine (Tet) on enhancing radiosensitivity of human nasopharyngeal carcinoma cell lines in vitro.
  
  
  METHODS
  CNE1 and CNE2 were exposed to radiation with or without Tet, the DNA damage of the cells were evaluated by neutral comet electrophoresis, and cell cycle and apoptosis were analyzed by flow cytometry.
  
  
  RESULTS
  The mean tail movements (TM) of CNE1 treated with radiation or radiation plus Tet were (7.13 ± 3.70) (X(-) ± s) and (13.61 ± 5.45), respectively (t = 2.784, P < 0.05), and TM of CNE2 treated with radiation or radiation plus Tet were (11.52 ± 4.04) and (18.85 ± 6.18), respectively (t = 3.089, P < 0.05). With the exposure to radiation or radiation plus Tet, the percentages of CNE1 in G2 phases were (42.62 ± 2.07)% and (17.02 ± 1.87)%, respectively (t = 23.173, P < 0.01), and the percentages of CNE2 in G2 phases were (34.82 ± 2.74)% and (19.64 ± 4.82)%, respectively(t = 16.500, P < 0.01). There was no significant difference in the apoptosis rates between the cells treated with radiation or radiation plus Tet regardless of CNE1 (17.24 ± 0.99)% vs (19.11 ± 1.24)%, and CNE2 (16.68 ± 0.27)% vs (18.51 ± 2.41)% (P > 0.05).
  
  
  CONCLUSIONS
  Tet can enhance radiosensitivity of human nasopharyngeal carcinoma cell lines. The mechanism could be related to abrogation of radiation-induced G2/M arrest and reduction of double-strand break repair capacity.
authors.affiliation: Department of Otorhinolaryngology Head and Neck Surgery, Third Affiliated Hospital of SUN Yat-sen University, Guangzhou 510630, China.
authors.forename: Kai
authors.initials: K
authors.lastname: Wang
authors.affiliation: Email: gehuazh@hotmail.com.
authors.forename: Gehua
authors.initials: G
authors.lastname: Zhang
authors.forename: Lihong
authors.initials: L
authors.lastname: Chang
authors.forename: Xifu
authors.initials: X
authors.lastname: Wu
authors.forename: Jingjia
authors.initials: J
authors.lastname: Li
authors.forename: Shimin
authors.initials: S
authors.lastname: Zhuang
authors.forename: Jun
authors.initials: J
authors.lastname: Wang
authors.forename: Li
authors.initials: L
authors.lastname: Daqing
mesh_terms: D017209:Apoptosis / Q000187:drug effects; D044182:Benzylisoquinolines / Q000008:administration & dosage / Q000494:pharmacology* / Q000633:toxicity*; D002277:Carcinoma; D045744:Cell Line, Tumor; D004260:DNA Repair; D006801:Humans; D000077274:Nasopharyngeal Carcinoma; D009303:Nasopharyngeal Neoplasms; D009362:Neoplasm Metastasis; D011836:Radiation Tolerance / Q000187:drug effects*
chemical_list: D044182:Benzylisoquinolines; C009438:tetrandrine