The Study On The Radiosensitivity Of Human Cancer Cells By Comet Assay

I The study on the radiosensitivity and repair of radiation-induced initial DNA damage detected in two human tumor cell lines by comet assayPurpose To discuss the correlation between radiosensitivity and radiation-induced initial DNA damage and repair ability detected by comet assay in two human tumor cell lines. Materials and Methods The radiation-induced initial DNA damage and repair were detected in both CNE-1 and 973 cell lines by the alkaline comet assay, optimized and standardized by Yang Weizhi research group, radiation biology department, CAMS &PUMC. The tail moment (TM) was used as the end point, to quantify the initial DNA damage (DNA single stand breaks) and subsequent repair ability. The cell-survival curve was plotted by classical colony assay, as the standard methodology. The results from the above two assays were compared, in the purpose of studying the correlation between initial DNA damage and radiosesitivity in two human tumor cell lines. The doses were given OGy, 2Gy, 5Gy, 10Gy and 15Gy to the cell lines to detect the initial DNA damage by comet assay; The dose 6Gy was given to detect the reparation of the initial DNA damage, and OGy, 1Gy, 2Gy, 3Gy, 5Gy, 7Gy and 10Gy to detect the radiosensitivity by colony assay, using 6MV-X ray, respectively. Result â‘  The initial DNA damage detected by comet assay before irradiation in CNE-1 and 973 cell lines demonstrated: The TM value of the two cell lines was very small in the control groups, and the shapes of DNA were described as roundness under the fluorescence microscope. With the increment of irradiation doses, the irradiation-induced initial DNA damage were...