SAHA对骨肉瘤143B细胞的抑制作用及机制研究

Inhibitory effect of SAHA on human osteosarcoma 143B cells and its related mechanism

目的:探讨伏立诺他(suberoylanilide hydroxamic acid,SAHA)对骨肉瘤细胞143B增殖和凋亡的影响及其可能机制。方法:以2~32μmol/L的SAHA作用于体外培养的143B细胞,采用MTT法检测SAHA对细胞活力的影响;选用SAHA作用的最适浓度和时间点进行后续的研究,并以加入最大剂量为1 ml/L的DMSO处理组作为空白对照。流式细胞仪检测细胞周期和凋亡水平变化;real-time PCR检测细胞周期和凋亡相关基因Cyclin D1、Bax、Bcl-2以及组蛋白去乙酰化酶(histone deacetylases,HDACs)的基因表达;化学比色法检测143B细胞中HDACs活性的变化;荧光素酶报告基因筛选SAHA处理后细胞内可能激活的信号通路;Western blot检测143B细胞中Cyclin D1、Bax、Bcl-2、cleaved-Caspase-3、cleaved-PARP及AP1蛋白的表达水平。结果:SAHA在2~32μmol/L浓度范围内可以抑制143B细胞的增殖,并且呈时间和剂量依赖性,48 h引起143B细胞半数抑制的浓度约为8μmol/L。SAHA可将143B细胞周期阻滞在G0/G1期,并且可以引起细胞的早期凋亡及Cyclin D1、Bcl-2、HDAC1、HDAC3的m RNA表达量下调,Bax的m RNA表达量上调;SAHA处理143B细胞后可以降低细胞内HDACs的活性,促进细胞中转录因子AP1的表达,并且能够下调细胞中Cyclin D1、Bcl-2的蛋白表达,促进Bax、cleaved-Caspase-3、cleaved-PARP及AP1的蛋白表达。结论:SAHA可以通过抑制HDACs的活性,激活AP1信号通路从而诱导143B细胞的凋亡及周期阻滞。

Objective:To investigate the effects of vorinostat(suberoylanilide hydroxamic acid,SAHA)on the proliferation and apoptosis of human osteosarcoma 143 B cells in vitro and to explore its underlying mechanisms. Methods:143B cells were treated with SAHA at various concentrations(2-32 μmol/L)and the cell viability was measured by MTT assay. The optimal concentration and time point of SAHA function were chosen for subsequent research,and the group adding the maximum dose of 1 ml/L DMSO was taken as blank control. Flow cytometry(FCM)was used to evaluate the level of cell cycle and apoptosis rate;the expression levels of Cyclin D1,Bax,Bcl-2,and HDACs m RNAs were examined by RT-PCR;the HDACs activity of 143 B cells was measured by chemical colorimetry. The probable signaling pathways activation after SAHA treatment was tested by luciferase reporter assay. Western blot was used to detect the protein expression levels of Cyclin D1,Bax,Bcl-2,cleaved-Caspase-3,cleaved-PARP and AP1. Results:The cell viability of 143 B cells was inhibited by SAHA(2-32 μmol/L)in a dose- and time-dependent manner,and the concentration of IC50 at 48 h was 8 μmol/L. Compared with that of control group,SAHA arrest the cell cycle at G0/G1 phase and induce apoptosis of 143 B cells. SAHA treatment inhibited the expression level of cyclin D1,bax,bcl-2 and HDACs while induced the bax expression,both in m RNA and protein levels. HDAC activity of 143 B cells treated with SAHA was reduced. Luciferase reporter assay indicated that AP1 transcription factor expression can be promoted by SAHA treatment. At the same time,the expression level of cleaved-Caspase-3,cleaved-PARP and AP1 protein were elevated significantly in 143 B cells after SAHA treatment. Conclusion:SAHA can induce apoptosis and cell cycle arrest of 143 B cells in vitro,which may be possibly via inhibition of the activity of HDACs and activation of the AP1 signaling pathways.