Ishii H, Tamauchi H, Gobe G C
Department of Pathology, School of Medicine, Kitasato University, Sagamihara, Japan.
Int J Exp Pathol. 1997 Jun;78(3):123-31. doi: 10.1046/j.1365-2613.1997.170350.x.
We have shown previously that cycloheximide (CHX), a potent protein synthesis inhibitor, induces high levels of apoptosis in Epstein-Barr virus free (EBV(-)) Burkitt's lymphoma (BJA-B) cells, with comparably reduced levels of apoptosis in the EBV positive (EBV(+)) cells. Modulation of CHX-induced apoptosis in EBV(-) and (+) B cells is reported here using concurrent treatment with phorbol ester (phorbol 12, 13-dibutyrate, PdBu). Cells were collected at 0, 3, 6, 12, 24 and 48 hours after treatment with (i) 1 microgram/ml CHX, (ii) 0.1 microgram/ml PdBu (1 hour pretreatment before 0 h), or (iii) CHX + PdBu (CHX added at 0 h, 1 hour after PdBu). Control cultures were untreated. Apoptotic, necrotic or viable cells were quantified using histological, ultrastructural and biochemical parameters. Protein synthesis was assessed using 35S-methionine incorporation. Intracellular calcium concentrations were measured using flow cytometry. PdBu alone had little effect on cell death: High levels of CHX-induced apoptosis in EBV(-) cells were significantly reduced by concurrent addition of PdBu (P < 0.005). In contrast, low levels of CHX-induced apoptosis in EBV(+) cells were not significantly altered by PdBu treatment. In EBV(-) cells, a negative relationship was observed between levels of apoptosis and calcium concentrations, whereas in EBV(+) cells, there was negligible correlation between these parameters. Thus high levels of CHX-induced apoptosis in EBV(-) cells occur via a PKC-dependent pathway, whereas CHX treatment of EBV(+) cells induces comparatively low levels of apoptosis that occur via a PKC-independent mechanism. The results application in the therapeutic intervention for cancers developing in association with EBV infection.
我们之前已经表明，强力蛋白质合成抑制剂环己酰亚胺（CHX）可诱导无爱泼斯坦 - 巴尔病毒（EBV(-)）的伯基特淋巴瘤（BJA - B）细胞发生高水平凋亡，而EBV阳性（EBV(+)）细胞中的凋亡水平相对降低。本文报道了使用佛波酯（佛波醇12,13 - 二丁酸酯，PdBu）同时处理来调节CHX诱导的EBV(-)和(+) B细胞凋亡。在以下处理后0、3、6、12、24和48小时收集细胞：（i）1微克/毫升CHX，（ii）0.1微克/毫升PdBu（在0小时前预处理1小时），或（iii）CHX + PdBu（在PdBu处理1小时后于0小时添加CHX）。对照培养物未进行处理。使用组织学、超微结构和生化参数对凋亡、坏死或存活细胞进行定量。使用35S - 甲硫氨酸掺入评估蛋白质合成。使用流式细胞术测量细胞内钙浓度。单独的PdBu对细胞死亡影响很小：同时添加PdBu可显著降低CHX诱导的EBV(-)细胞中的高水平凋亡（P < 0.005）。相反，PdBu处理并未显著改变CHX诱导的EBV(+)细胞中的低水平凋亡。在EBV(-)细胞中，观察到凋亡水平与钙浓度之间呈负相关，而在EBV(+)细胞中，这些参数之间的相关性可忽略不计。因此，CHX诱导的EBV(-)细胞中的高水平凋亡通过PKC依赖性途径发生，而CHX处理EBV(+)细胞诱导的凋亡水平相对较低，通过PKC非依赖性机制发生。这些结果可应用于与EBV感染相关的癌症的治疗干预。
