关键词: 辐射, 电离, 前列腺肿瘤, PC-3细胞

Abstract: Objective To study the effects of IL-24 gene combined with ionizing radiation on apoptosis in PC-3 cell line in order to prepare the ground for combined therapy of IL-24 gene and ionzing raditaion for tumor.Methods The 　experiment was divided into sham irradiation group and irradiation groups with different irradiation doses,which were 2,4,6,8,12 and 18 Gy, respectively.To detect the expression of IL-24 gene,three groups were included,which were control group (1×PBS),vector group and IL-24 gene group.To detect the apoptotic effect of IL-24 gene combined with ionization radiation on PC-3 cell line,the experiment was divided into control group,vector group,IL-24 gene group,irradiation group (6 Gy),vector combined with irradiation group and IL-24 gene combined with irradiation group.Alkaline lysis assay was used to extract and purify the plasmid.Plasmids were transfected into PC-3 cell line by polyethyleneimine（PEI）in vitro.The expression of the interest gene was detected by RT-PCR.The changes of apoptosis in PC-3 cell line were detected by flow cytometry（FCM）using the staining of Annexin-V and PI.Results Compared with sham-irradiation group,the apoptotic percentage of PC-3 cell line did not show marked change after 2 and 4 Gy X-rays irradiation for 48 h（P>0.05）.The apoptotic percentage was increased significantly after X-rays irradiation with the dose of 6 Gy（P<0.01），and the mean apoptotic percentage of PC-3 cell line was increased by a factor of 1.6 to 3.0 compared with sham-irradiation group.The expression of IL-24 gene could be observed in PC-3 cell line transfected by IL-24 gene except in control group and vector group，and all of them showed the expression of GAPDH gene.As compared with the other groups,the number of early apoptotic cells of PC-3 cell line in the IL-24 gene combined with irradiation group was increased significantly （P<0.05） except in irradiation roup.The number of late apoptotic and necrotic cells of PC-3 cell line in the IL-24 gene combined with irradiation group was increased significantly compared with control group,irradiation group and vector combined with irradiation group（P<0.05,P<0.01）.As compared with the other groups,the total number of apoptotic and necrotic cells in the IL-24 gene combined with irradiation group was increased significantly （P<0.05，P<0.01） except in IL-24 gene group.Conclusion IL-24 gene combined with X-rays irradiation could induce effective apoptosis in PC-3 cell line.

Key words: irradiation, ionizing, prostatic neoplasms, PC-3 cell line