The Direct Effects of Different Irradiation Methods on The Survival of Laryngeal Squamous Carcinoma Hep2 Cells

Abstract Radiotherapy plays an important role in the treatment of laryngeal squamous cell carcinoma. However, radiation resistance is an important cause of radiotherapy failure. To determine the direct effects of different irradiation methods on the survival of Hep2 cells, three different irradiation methods were used in vitro to explore the effects on the colony formation, cycle and apoptosis, showing that different irradiation methods had inhibitory effects on the colony formation of Hep2 cells. Radioactive 125I continuous low dose rate radiation (CLDR) has a stronger inhibitory function, and single dose radiation (SDR) is also superior to fractionated dose radiation (FDR). The G1 phase decreased more significantly, while the G2/M phase ratio also increased significantly in CLDR group. The CLDR group was more significant increase in the early apoptosis and general apoptosis. During these process, the production of higher γ-H2AX, Cyclin D1, Cdc2, NF-κB p21, CyclinB1 and lower p-Cdc25c in CLDR group were observed. Taken together, the continuous low-dose rate irradiation of 125I seeds can significantly increase the apoptosis rate of Hep2 cells, resulting in continuous G2/M phase arrest and significantly inhibiting the proliferation ability of Hep2 cells