低剂量辐射对肿瘤细胞凋亡、细胞周期以及凋亡相关蛋白bcl-2的影响

Effects of low dose radiation on tumor apoptosis,cell cycle progression and changes of apoptosis-related protein bcl-2 in tumor-bearing mice

目的 探讨低剂量辐射对小鼠移植肿瘤细胞的凋亡、细胞周期以及相关蛋白bcl 2表达的影响。方法 昆明种雄性小鼠左后肢腹股沟皮下接种S1 80肉瘤细胞 ,接种后 7dγ射线全身照射 75mGy,照射后 2 4 ,48h分别处死 ,直接测量肿瘤大小变化 ,并取肿瘤组织分别进行流式细胞仪分析凋亡、细胞周期 ,以免疫组化染色半定量分析凋亡相关蛋白bcl 2表达的变化。结果 与直接荷瘤组相比 ,低剂量照射组肿瘤生长缓慢 (P <0 0 5) ,2 4h后肿瘤细胞阻滞于G1 期 ,bcl 2蛋白表达下降 ,48h后肿瘤细胞凋亡增加 (P <0 0 0 1 )。结论 低剂量辐射可使机体肿瘤细胞阻滞于G1 期 ,并通过凋亡相关蛋白表达变化导致肿瘤细胞凋亡增加 ,明显提高机体抗肿瘤的作用 。

Objective\ To study the effect of low dose radiation (LDR) on tumor apoptosis,cell cycle progression and changes of apoptosis\|related protein bcl\|2 in tumor\|bearing mice. Methods\ Kunming stain male mice were implanted with S180 sarcoma cells in the left inguen subcutaneously as an in situ experimental animal model.Seven days after implantation,the mice were given 75 mGy whole\|body γ\|ir radiation.At 24 and 48 h after irradiation,all mice were sacrificed to measure the tumor volume,and tumor cell apoptosis,cell cycle progression were analyzed by flow cytometry.The expression of apoptosis\|related protein bcl\|2 and the apoptotic rate of tumor cells were observed by immunohistochemistry and electron microscopy. Results\ Tumor growth was significantly slowed down after LDR( P <0 05).The tumor cells were arrested in G 1 phase and the expression of bcl\|2 protein decreased at 24 h.Apoptotic rate of tumor cells increased significantly at 48 h after LDR. Conclusion\ LDR could cause a G 1\|phase arrest and increase the apoptosis of tumor cells through the low level of apoptosis\|related protein bcl\|2 in the tumor\|bearing mice.The organized immune function and anti\|tumor ability are markedly increased after LDR.Our study provides practical evidence of clinical application to cancer treatment.\;