Biological effects of low-dose-rate irradiation of pancreatic carcinoma cells in vitro using 125I seeds

• Published in: World journal of gastroenterology : WJG 2015-02, Vol.21 (8), p.2336-2342
• Main Authors: Wang, Zhong-Min, Lu, Jian, Zhang, Li-Yun, Lin, Xiao-Zhu, Chen, Ke-Min, Chen, Zhi-Jin, Liu, Fen-Ju, Yan, Fu-Hua, Teng, Gao-Jun, Mao, Ai-Wu
• Format: Article
• Language: English
• Subjects: Apoptosis - radiation effects; Basic Study; Brachytherapy - methods; Carcinoma, Pancreatic Ductal - pathology; Carcinoma, Pancreatic Ductal - radiotherapy; Cell Line, Tumor; Cell Survival - radiation effects; Dose-Response Relationship, Radiation; G2 Phase Cell Cycle Checkpoints - radiation effects; Humans; Iodine Radioisotopes; Pancreatic Neoplasms - pathology; Pancreatic Neoplasms - radiotherapy
• ISSN: 1007-9327; 2219-2840
• DOI: 10.3748/wjg.v21.i8.2336

To determine the mechanism of the radiation-induced biological effects of 125I seeds on pancreatic carcinoma cells in vitro. SW1990 and PANC-1 pancreatic cancer cell lines were cultured in DMEM in a suitable environment. Gray's model of iodine-125 (125I) seed irradiation was used. In vitro, exponential phase SW1990, and PANC-1 cells were exposed to 0, 2, 4, 6, and 8 Gy using 125I radioactive seeds, with an initial dose rate of 12.13 cGy/h. A clonogenic survival experiment was performed to observe the ability of the cells to maintain their clonogenic capacity and to form colonies. Cell-cycle and apoptosis analyses were conducted to detect the apoptosis percentage in the SW1990 and PANC-1 cells. DNA synthesis was measured via a tritiated thymidine (3H-TdR) incorporation experiment. After continuous low-dose-rate irradiation with 125I radioactive seeds, the survival fractions at 2 Gy (SF2), percentage apoptosis, and cell cycle phases of the SW1990 and PANC-1 pancreatic cancer cell lines were calculated and compared. The survival fractions of the PANC-1 and SW1990 cells irradiated with 125I seeds decreased exponentially as the dose increased. No significant difference in SF2 was observed between SW1990 and PANC-1 cells (0.766±0.063 vs 0.729±0.045, P