Department of Immunology, Umeå University, SE-90185 Umeå, Sweden.
Anticancer Res. 2009 Nov;29(11):4361-6.
The apoptotic signalling pathways involved in the delayed type of apoptosis occurring in HeLa Hep2 cells following radiation were investigated.
HeLa Hep2 cells were exposed to 5 Gy of cobalt-60 radiation. The activation of caspase-2, caspase-8, caspase-9 and effector caspase-3 was investigated by caspase assay plates and Western blots. Cleavage of poly (ADP-ribose) polymerase (PARP) was analysed on Western blots. HeLa Hep2 cells were irradiated with or without preincubation with inhibitors of protein synthesis (cycloheximide, CHX) and caspases, followed by TUNEL staining and caspase assay plate evaluation.
Initiator caspases-2, -8, -9, and effector caspase-3, were found to be activated and PARP cleaved following irradiation. CHX completely inhibited the caspase activation and the associated apoptosis. Pretreatment with caspase-2 inhibitor indicated that caspase-2 was involved in the execution of the apoptosis.
Activation of the apoptotic signalling pathways following irradiation of HeLa Hep2 cells includes components from the intrinsic as well as the extrinsic pathways and seems to require de novo protein synthesis.
研究了钴-60 辐射后 HeLa Hep2 细胞中迟发性细胞凋亡涉及的凋亡信号通路。
用钴-60 辐射暴露 HeLa Hep2 细胞。通过 caspase 测定板和 Western blot 研究 caspase-2、caspase-8、caspase-9 和效应 caspase-3 的激活。Western blot 分析聚（ADP-核糖）聚合酶（PARP）的切割。用或不用蛋白合成抑制剂（环己酰亚胺，CHX）和半胱天冬酶预处理后，对 HeLa Hep2 细胞进行照射，然后进行 TUNEL 染色和 caspase 测定板评估。
发现照射后起始半胱天冬酶-2、-8、-9 和效应半胱天冬酶-3 被激活，PARP 被切割。CHX 完全抑制了半胱天冬酶的激活和相关的凋亡。用半胱天冬酶-2 抑制剂预处理表明半胱天冬酶-2 参与了细胞凋亡的执行。
HeLa Hep2 细胞照射后凋亡信号通路的激活包括内源性和外源性途径的成分，似乎需要新的蛋白质合成。
