Radiation-induced autophagy in colon cancer cells and its effect in radiation responses / 中华放射医学与防护杂志

ABSTRACT

Objective To observe the autophagy induced by heavy ion and X-ray radiations in SW480 cells and its effect in radiation responses.Methods The cellular ultrastructure was observed with a transmission electron microscope (TEM).The autophagy vesicles were labeled by monodansylcadaverin (MDC) fluorescence.The levels of LC3 which were induced by radiation and rapamycin were measured by Western blot assay.Cell proliferation was detected by MTT assay.The invasion of SW480 colon cells was measured with a Transwell.Cell wound healing assay was used to observe the migration of SW480 colon cells.Results Heavy ion and X-ray radiation could induce autophagy in SW480 cells in a dose dependent manner i.e., the autophagy level increased along with irradiation dose (F =458.526, P ＜ 0.05) , but this induction of autophagy was inhibited by chloroquine.Rapamycin could also induce autophagy in SW480 cells and it had a synergistic effect with irradiation (F =189.393, P ＜ 0.05).The abilities of invasion, migration and proliferation of SW480 cells were reduced by irradiation and the combination treatment of irradiation and rapamycin (F =194.692, 629.917, 302.903, P ＜ 0.05) , but they were enhanced by chloroquine (F =194.692, 629.917, 302.903, P ＜ 0.05).Conclusions Ionization radiation causes cell death by inducing autophagy.