EGFR antibody radiosensitivity enhancement on CL187 cancer cells after continous low dose rate irradiation

Objective: To investigate the radiosensitivity enhancement on CL187 cancer cell lines after continous low-dose-rate irradiation of 125I seeds blocked by EGFR antibody. Methods: There were control group, the irradiation or plus EGFR antibody group, with 3 samples in each group. Clongenic assay was used to detect the survival of cells. The cell cycle distribution and apoptosis were analyzed by flow cytometry. Results: The survival fraction of CL187 cells were lower after blocked by EGFR antibody at the same dose irradiation. The SER were 1.34, 1.59 and 1.98 when the antibody concentration were 2, 5 and 10 nmol/L, respectively. The irradiation plus antibody led to more apoptosis (39.86% ± 4.38%) of CL187 cells than the irradiation (21.57% ± 2.97%) plused antibody (12.49% ± 1.59%) worked alone. Comparison: of the low dose rate irradiation related to G2/M cell cycle arrest (46.41% ± 4.48%), More G1 cell cycle arrest (84.51% ± 3.42%) walked together along with the EGFR antibody. Conclusions: EGFR antibody could enhance the cell radiosensitivity after continuous low-dose-rate. irradiation. The cell cycle redistribution and apoptosis might be the main mechanism of the radiosensitivity enhancement. (authors)