二氢青蒿素诱导乳腺癌细胞凋亡的分子机制初探

Effects of dihydroartemisinin on proliferation and apoptosis of breast carcinoma cell line T47D

目的:研究二氢青蒿素(DHA)对乳腺癌细胞系T47D的增殖、凋亡作用的影响,初步探讨其抗癌作用的分子机制。方法:以乳腺癌细胞T47D为研究对象,观测不同浓度和作用时间的DHA对T47D细胞的作用,MTT噻唑蓝比色法检测对细胞的增殖抑制作用,分别PI单染及Annexin-V双染法流式细胞术分析细胞周期分布和早期凋亡率的变化,RT-PCR和蛋白质印迹法检测细胞凋亡相关蛋白的表达。结果:DHA对T47D细胞有增殖抑制作用且呈剂量和时间依赖性,DHA作用24、48和72h的IC50值分别为60.03、33.86和17.18μmol/L;流式细胞仪检测细胞阻滞于G0/G1期,随药物剂量增大(20、40和60μmol/L),G0/G1期比例逐渐增高(42.76%、49.71%和63.01%),S期比例降低(48.45%、42.41%和30.98%);Annexin-V双染法示早期细胞凋亡率呈明显剂量依赖性升高〔(20.81±0.68)%、(30.90±0.73)%、(45.32±2.17)%(n=3)〕;RT-PCR检测显示,DHA作用后细胞凋亡诱导因子BimmR-NA的表达量升高;蛋白质印迹法检测DHA作用48h凋亡相关蛋白tbid和Caspase-8表达增强,且呈一定剂量依赖关系。结论:DHA能显著抑制人乳腺癌细胞T47D生长,影响细胞周期,诱导细胞凋亡,其分子机制可能与促使Bim、tbid和Caspase-8表达增强的内源性凋亡途径有关。

OBJECTIVE： To observe the effect of dihydroartemisinin （DHA） on the proliferation and apoptosis in human breast carcinoma cell line T47D in vitro and explore the mechanism. METHODS： The inhibition of proliferation of T47D ceils was determined by MTT assay. The distribution of cell cycle and apoptosis were analyzed by using flow cytometry through PI and AnnexinV/PI double-labeled staining. The expression of Bim mRNA was detected by RT-PCR, and the expression of cell apoptosis-associated gene proteins was detected with Western blot technique. RESULTS： Dihydroartemisinin could inhibit the proliferation of T47D cells and the inhibition was depended on the exposure dose and time. The ICs0 values after treatment by DHA for were 60.03, 33.86 and 17.18 μmol/L. After treated with Dihydroartemisinin for 24,48 and 72 h, the analysis of cell cycle indicated that Dihydroartemisinin blocked ceils at G0/G1 phases, showed an increase of G0/G1 phase （42.76 %, 49.71%, 63.01%） and a decrease of S phase （48.45%, 42.41%, 30.98%）. When treated by 20,40,60 μmol/L of DHA for 48 h, the early apoptosis rates of breast cancer T47D cell were （20.81±0.68）%, （30.90±0.73）% , （45.32±2.17）% （n= 3）, The higher the concentration, the higher the early apoptosis rates. The expression of Bim mRNA was up regulated, and tbid, caspase 8 expressions were up-regulated. CONCLUSIONS： DHA can inhibit the proliferation of the breast carcinoma cell line T47D by regulating the cell cycle through arresting cells at G0/G1 phase and inducing apoptosis. The anti-tumor effects may be related to the up-regulation of the expressions of gene Bim, tbid, and Caspase-8 proteins.