Calvaruso G, Carabillò M, Giuliano M, Lauricella M, D'Anneo A, Vento R, Tesoriere G
Department of Cell and Developmental Biology, Section of Biochemistry, University of Palermo, Policlinico, Palermo, Italy.
Int J Oncol. 2001 Jun;18(6):1233-7. doi: 10.3892/ijo.18.6.1233.
Our results demonstrate that sodium phenylbutyrate, a compound with a low degree of toxicity, exerted a cytotoxic effect on human retinoblastoma Y79 cells in a time- and dose-dependent manner. Treatment of Y79 cells for 72 h with phenylbutyrate reduced cell viability by 63% at 2 mM and 90% at 4 mM. Cell death caused by phenylbutyrate exhibited the typical features of apoptosis, as shown by light and fluorescent microscopy. Western blot analysis demonstrated that exposure of Y79 cells to phenylbutyrate decreased the level of the antiapoptotic factor Bcl-2 and induced the activation of caspase-3, a key enzyme in the execution phase of apoptosis. Moreover, treatment with phenylbutyrate markedly increased the level of acetylated histone-H3. Combined treatment with phenylbutyrate and topotecan, a topoisomerase I-inhibitor, resulted in a clear synergistic effect. We suggest that the effects exerted by phenylbutyrate on Y79 cells essentially depend on modifications of gene expression consequent to histone hyperacetylation.
我们的结果表明，苯丁酸钠作为一种低毒化合物，对人视网膜母细胞瘤Y79细胞具有时间和剂量依赖性的细胞毒性作用。用苯丁酸盐处理Y79细胞72小时，在2 mM时细胞活力降低63%，在4 mM时降低90%。苯丁酸盐引起的细胞死亡表现出典型的凋亡特征，这通过光学显微镜和荧光显微镜观察得以证实。蛋白质免疫印迹分析表明，Y79细胞暴露于苯丁酸盐会降低抗凋亡因子Bcl-2的水平，并诱导caspase-3的激活，caspase-3是凋亡执行阶段的关键酶。此外，用苯丁酸盐处理显著增加了乙酰化组蛋白-H3的水平。苯丁酸盐与拓扑异构酶I抑制剂拓扑替康联合治疗产生了明显的协同效应。我们认为，苯丁酸盐对Y79细胞的作用主要取决于组蛋白高度乙酰化导致的基因表达修饰。
