›› 2012, Vol. 24 ›› Issue (2): 100-107.doi: 10.3969/j.issn.1004-616x.2012.02.005

• 论著 • Previous Articles     Next Articles

Relationship between characteristics of MnSOD expression and radiosensitivity

SUN Guo-gui，HU Wan-ning，WANG Ya-di，LI Yun-ming，JING Shao-wu，LI Cheng-lin，CUI Da-wei   

  1. 1. Department of Chemoradiotherapy, Tangshan People’s Hospital, Tangshan 063000; 2. Department of Radiotherapy, The Military General Hospital of Beijing PLA, Beijing 100700; 3. Department of Quality Management, The Military General Hospital of Chengdu PLA, Chengdu 610083; 4. Department of Radiotherapy, The Fourth Hospital of Hebei Medical Univercity, Shijiazhuang 050011;
  • Received:2011-08-23 Revised:2011-12-14 Online:2012-03-30 Published:2012-03-30
  • Contact: WANG Ya-di

PDF (PC)

979

Abstract: 【ABSTRACT】 OBJECTIVE: To explore effects of manganese superoxide dismutase (MnSOD) overexpression on radiosensitivity in the esophageal cancer cell line under the action of nitric oxide (NO). METHODS：Overexpression of MnSOD cDNA was obtained by lentivirus to get two stable transfected TE-1 cell lines of MnSOD with moderate to high expression (TE-1Mm，TE-1Mh) and empty vector cell (TE-1Mn). Reverse transcription polymerase chain reaction (RT-PCR)and western blot were then introduced to detect the target genes with respect to its expression in esophageal TE-1 cells. Additionally，colorimetric 3-[4，5-dimethy thiazol-2-yl]-2，5-diphenyltetrazolium bromide (MTT) assay，flow cytometry (FCM) and western blot were also used to assess the influence of the moderate to high overexpression of MnSOD that might be found on proliferation of TE-1 cells treated with sodium nitroprusside and irradiation. RESULTS：RT-PCR and western blot showed that TE-1 cells transfected with MnSOD cDNA contained the target genes at different levels，suggesting that esophageal cancer cell of stable transfection had been successfully constructed. MTT and FCM revealed that moderate overexpression of MnSOD decreased growth rates，increased apoptosis；while high overexpression of MnSOD increased growth rates and decreased apoptosis.When combined with radiation or NO，moderate overexpression of MnSOD reduced growth rates，enhanced cell apoptosis and radiosensitivity of esophageal cancer cells，whereas high MnSOD overexpression had the opposite effect. Western blot and FCM demonstrated that TE-1Mh cells decreased MnSOD protein expression and ROS levels treated with radiation or NO compared with TE-1Mm cell. CONCLUSION：Moderate overexpression of MnSOD increased the radiosensitivity of esophageal cancer cells，whereas high MnSOD overexpression had the opposite effect on cell radiosensitivity. This finding suggests a potential new method to kill certain radioresistant tumors and to provide radioresistance to normal cells.

Key words: manganese superoxide dismutase, nitric oxide, esophageal carcinoma, radiosensitivity