title: Nested PCR for mtDNA-4977-bp deletion and comet assay for DNA damage - a combined method for radiosensitivity evaluation of tumor cells.
abstract: To identify an effective method of evaluating the radiosensitivity of human tumor cell linesin vitro, the present study adopted mtDNA-4977-bp deletion coupled with comet assay. The three human tumor cell lines applied were HepG2, EC-9706 and MCF-7. The surviving fraction (SF), ratio of the mtDNA-4977-bp deletion and DNA damage were detected by MTT assay, nested polymerase chain reaction (PCR) technique and comet assay, respectively. Clearly, lower SFs were found for the HepG2and EC-9706 cells as compared with the MCF-7 cells following irradiation at doses of 2, 4 and 8 Gy, indicating a higher radiosensitivity for the HepG2and EC-9706 cells. Additionally, no significant differences were identified in the mtDNA-4977-bp deletions found among HepG2, EC-9706 and MCF-7 cells by PCR following 1- or 4-Gy γ-ray irradiation, while increased deletion ratios of mtDNA-4977 bp were observed in HepG2and EC-9706 cells following 8-Gy irradiation, in contrast to decreases in MCF-7 cells. The most notable differences among these three tumor cell lines were observed by comet assay following 8-Gy γ-ray irradiation. A combined method of nested PCR and comet assay, therefore, is the most effective and accurate method in evaluating the radiosensitivity of tumor cells.
authors.affiliation: Institute of Radiation Medicine, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin Key Laboratory of Molecular Nuclear Medicine, Tianjin 300192, P.R. China ; Department of Human Anatomy, The Medical School of Inner Mongolia University for the Nationalities, Tongliao, Neimenggu 028041, P.R. China.
authors.forename: Jianguo
authors.initials: J
authors.lastname: Li
authors.affiliation: Institute of Radiation Medicine, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin Key Laboratory of Molecular Nuclear Medicine, Tianjin 300192, P.R. China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Institute of Radiation Medicine, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin Key Laboratory of Molecular Nuclear Medicine, Tianjin 300192, P.R. China.
authors.forename: Liqing
authors.initials: L
authors.lastname: DU
authors.affiliation: Institute of Radiation Medicine, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin Key Laboratory of Molecular Nuclear Medicine, Tianjin 300192, P.R. China.
authors.forename: Chang
authors.initials: C
authors.lastname: Xu
authors.affiliation: Institute of Radiation Medicine, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin Key Laboratory of Molecular Nuclear Medicine, Tianjin 300192, P.R. China.
authors.forename: Jia
authors.initials: J
authors.lastname: Cao
authors.affiliation: Institute of Radiation Medicine, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin Key Laboratory of Molecular Nuclear Medicine, Tianjin 300192, P.R. China.
authors.forename: Qin
authors.initials: Q
authors.lastname: Wang
authors.affiliation: Institute of Radiation Medicine, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin Key Laboratory of Molecular Nuclear Medicine, Tianjin 300192, P.R. China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Liu
authors.affiliation: Institute of Radiation Medicine, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin Key Laboratory of Molecular Nuclear Medicine, Tianjin 300192, P.R. China.
authors.forename: Feiyue
authors.initials: F
authors.lastname: Fan
keywords: DNA damage; comet assay; mitochondrial DNA; nested PCR; radiosensitivity