Barbarotto Elisa, Corallini Federica, Rimondi Erika, Fadda Roberto, Mischiati Carlo, Grill Vittorio, Vaccarezza Mauro, Celeghini Claudio
Department of Morphology and Embryology, University of Ferrara, Via Fossato di Mortara 66, 44100 Ferrara, Italy.
J Cell Biochem. 2008 May 15;104(2):595-605. doi: 10.1002/jcb.21649.
We have compared the cytotoxic/cytostatic responses of the SKW6.4 lymphoblastoid B-cells to the alkylating agent chlorambucil, the purine analog fludarabine, the non-genotoxic activator of the p53 pathway, Nutlin-3, used alone or in association with the death-inducing ligand recombinant TRAIL. Exposure to chlorambucil, fludarabine, and Nutlin-3 induced p53 accumulation and variably affected cell cycle progression in SKW6.4 lymphoblastoid cells. In particular, chlorambucil induced cell cycle accumulation at the G2/M checkpoint; Nutlin-3 induced early cell cycle arrest at the G1/S checkpoint, while fludarabine showed an intermediate behavior. On the other hand, recombinant TRAIL alone did not affect cell cycle progression but induced a rapid increase of apoptosis. Analysis of the gene expression profile of the p53-transcriptional targets showed distinct features between chlorambucil, Nutlin-3 and fludarabine, which likely account for their differential effect on cell cycle in SKW6.4 cells. In particular, chlorambucil upregulated the steady-state mRNA expression of SFN/14-3-3sigma, a gene involved in G2/M cell cycle arrest. Of note, all agonists upregulated TRAIL-R2 expression in SKW6.4 cells both at the mRNA and protein levels. Consistently, pretreatment with chlorambucil, fludarabine and Nutlin-3 enhanced SKW6.4 sensitivity to TRAIL-mediated apoptosis.
我们比较了SKW6.4淋巴母细胞样B细胞对烷化剂苯丁酸氮芥、嘌呤类似物氟达拉滨、p53途径的非基因毒性激活剂Nutlin-3单独使用或与死亡诱导配体重组肿瘤坏死因子相关凋亡诱导配体（TRAIL）联合使用时的细胞毒性/细胞生长抑制反应。暴露于苯丁酸氮芥、氟达拉滨和Nutlin-3会诱导p53积累，并对SKW6.4淋巴母细胞样细胞的细胞周期进程产生不同影响。特别是，苯丁酸氮芥诱导细胞周期在G2/M检查点积累；Nutlin-3诱导细胞周期在G1/S检查点早期停滞，而氟达拉滨表现出中间状态。另一方面，单独的重组TRAIL不影响细胞周期进程，但会诱导凋亡迅速增加。对p53转录靶点的基因表达谱分析显示，苯丁酸氮芥、Nutlin-3和氟达拉滨之间存在明显特征，这可能解释了它们对SKW6.4细胞细胞周期的不同影响。特别是，苯丁酸氮芥上调了参与G2/M细胞周期停滞的基因SFN/14-3-3sigma的稳态mRNA表达。值得注意的是，所有激动剂均在mRNA和蛋白质水平上调了SKW6.4细胞中TRAIL-R2的表达。一致地，用苯丁酸氮芥、氟达拉滨和Nutlin-3预处理可增强SKW6.4对TRAIL介导的凋亡的敏感性。
