1 徐州医科大学研究生学院临床学院，江苏 徐州 221004
2 徐州市肿瘤医院放射治疗科，江苏 徐州 221004
Antagonism of dexamethasone to radiation bystander effect and its re-transmission
CorrespondingAuthor: ZHANG Xuguang Email: firstname.lastname@example.org
Foundation: This work was supported by the Natural Science Foundation of Jiangsu Province, China (BK20151156).
Objective: To observe the antagonism of dexamethasone on radiation bystander effect and its re-transmission. Methods: 6MV X-ray irradiation of mouse ovarian cancer cell line NUTU19 was used to prepare the first generation conditioned medium. The first-generation effecter cell line NUTU19 and intestinal mucosal epithelial IEC-6 were treated with the second generation conditioned medium from the secretion of the first-generation effecter cells. The second-generation effecter cell line NUTU19, IEC-6 and mice lymphocyte were treated with the second generation conditioned medium. The cell growth activity and apoptotic level were detected. Dexamethasone was used as parallel treatment control in all experimental groups. Results: There was no protective effect on NUTU19 cell lines treated with conditioned medium of the first and second generation conditioned medium, and the intestinal mucosal epithelial IEC-6 cell lines was significantly protected, reaching 23% in the first generation conditioned medium and 33% in the second generation conditioned medium. The conditioned medium of the first and second generation did not show any special damage to the lymphocyte of mice, and dexamethasone did not show the effect of increasing cell viability. After the intervention of dexamethasone, the apoptotic level of ovarian cancer cell lines treated with conditioned medium of the first and second generations decreased by 5.8% and 4.0%, and the epithelial cells of intestinal mucosa decreased by 6% and 3%. The killing effect of conditioned medium and the protective effect of dexamethasone were not observed in mouse lymphocytes. Conclusion: Under certain conditions, dexamethasone can antagonize the injury of intestinal epithelial cells and lymphocyte by radiation bystander effect, and can also antagonize the re-transmission of radiation bystander effect.Keywords： radiation bystander effect; re-transmission; dexamethasone