Rainaldi Gabriella, Ferrante Antonella, Indovina Pietro Luigi, Santini Maria Teresa
Laboratorio di Ultrastrutture, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Rome, Italy.
Anticancer Res. 2003 May-Jun;23(3B):2505-18.
This study investigates cell growth and death (apoptosis and necrosis) in actively proliferating MG-63 osteosarcoma spheroids in response to two doses of ionizing radiation (5 and 30 Gy). Cell growth was examined by growth curves and by cell cycle analyses utilizing flow cytometry. Death was examined in both disaggregated and whole spheroids by the chromatin dye Hoechst and by Western blot analysis of the bcl-2 family of proteins known to be involved in the apoptotic process. The results indicate that after exposure to 5 Gy MG-63 spheroids die by apoptosis, while after exposure to 30 Gy they die by necrosis. The analysis of the bcl-2 family of proteins demonstrates that bcl-2, bax and bcl-XL are involved in triggering apoptosis in spheroids exposed to 5 Gy. The possibility of studying the mechanisms responsible for radiation-induced cell death in three-dimensional spheroids (which represent much more closely in vivo tumors) is extremely important if the foundations for more selective and controllable clinical radiotherapeutic protocols are to be laid.
本研究调查了处于活跃增殖状态的MG-63骨肉瘤球体在接受两剂电离辐射（5 Gy和30 Gy）后细胞的生长与死亡情况（凋亡和坏死）。通过生长曲线以及利用流式细胞术进行细胞周期分析来检测细胞生长。通过染色质染料Hoechst以及对已知参与凋亡过程的bcl-2蛋白家族进行蛋白质免疫印迹分析，在解离的和完整的球体中检测细胞死亡情况。结果表明，暴露于5 Gy后，MG-63球体通过凋亡死亡，而暴露于30 Gy后，它们通过坏死死亡。对bcl-2蛋白家族的分析表明，bcl-2、bax和bcl-XL参与了暴露于5 Gy的球体中凋亡的触发过程。如果要为更具选择性和可控性的临床放射治疗方案奠定基础，那么研究三维球体（其更接近体内肿瘤）中辐射诱导细胞死亡机制的可能性极为重要。
