Radiosensitivity Of Cervical Carcinoma Cell Lines Studied

Background and objectivesCarcinoma of uterine cervix is a common malignant tumor of the female reproductive system, which ranked third in incidence and fourth in fatality rate according to the latest global cancer statistics. Radiotherapy plays an important role in the treatment of cervical cancer. Especially in recent years, many new irradiation technologies came into practice, such as Intensity Modulation Radiated Therapy (IMRT), Volume Modulation Radiated Therapy (VMRT), and Helical Tomotherapy (HT). Compared with conventional radiotherapy, there is no clear conclusion that the new technology model can significantly increase control rates of cervical cancer. This study was designed to explore the effect of different doses and dose rates on different types of cervical cancer cell lines, in order to provide a theoretical and practical basis for further research and clinical treatment.MethodsWe established three cell radiosensitivity models with three cervical cancer cell lines: Caski, Siha and HeLa cell line. We used clonogenic assay to analyse radiosensitivity differences of the three cell lines. Fitting with "single-hit multi-target model"[SF=1(1-eD/D0) N], cell surviving curves were drawn, from which radiosensitivity parameter Do, Dq, N, and SF2can be calculated. MTT assay was included to draw cell survival curves of different doses. Clonogenic assay was adopted to analyse the radiosensitivity and its difference under different dose rates for each of the three cell lines.Results1. Six-well plates were inoculated with cell density of2.5×102cells, and radiation dose selected was2Gy,4Gy,6Gy,8Gy, and10Gy respectively.2. Radiosensitivity parameters of three cervical cancer cell lines:SF2(survival fraction of2Gy) of Caski of was57.37%, Siha was74.77%, and Hela was70.62%(P=0.001<0.05). MTT results showed that the intergroup difference of cell survival curve was present from120h to168h for the three cell lines (Caski, Siha, and Hela), while no significant difference could be found within96h (P>0.05).3. There was no significant difference regarding the cell survival fraction among the subgroups of different dose rates(200cGy/min,400cGy/min, and600cGy/min) for each of the three cell lines (Caski, Siha and Hela).ConclusionThe radiosensitivity of the three cell lines was ranked from high to low as Caski, The radiosensitivity of the three cell lines was ranked from high to low as Caski, Hela, and Siha, and the sublethal damage repair capacity of Siha was the best, followed by Hela, and then Caski. The changes of dose rates may not affect the survival fraction of each cell line.