异硫氰酸苯乙酯通过上调ROS激活p53诱导MCF-7细胞凋亡机制的研究

Activating p53 by ROS contributes to phenylethyl isothiocyanate-induced apoptosis in MCF-7 cells

目的:研究异硫氰酸苯乙酯(phenethyl isothiocyanate,PEITC)诱导人乳腺癌MCF-7细胞的凋亡的作用及分子机制。方法:采用MTS观察PEITC对MCF-7细胞活力的影响。用Hoechst33342染色法和Annexin V/PI双染法检测细胞凋亡率。细胞内的活性氧水平用DCFH-DA荧光探针标记后检测。同时,p53和Bax蛋白用免疫印记法检测。结果:PEITC对MCF-7细胞生长抑制作用呈现剂量依赖性。用15μmol/L的PEITC处理9 h后可明显地诱导细胞凋亡及凋亡相关蛋白Bax的表达。PEITC处理9 h后可以显著性上调MCF-7细胞内活性氧水平。用N-乙酰半胱氨酸(NAC,活性氧清除剂)处理后可以抑制由PEITC诱导的凋亡。同时,NAC还可以抑制PEITC诱导的细胞凋亡和p53蛋白的表达。结论:PEITC主要是通过凋亡途径抑制MCF-7细胞生长。其作用机制可能是通过上调细胞内氧化应激水平进而激活p53蛋白及其下游凋亡通路促发凋亡。

AIM： To explore the inhibiting effect and its molecular mechanism of phenylethyl isothiocyanate（ PEITC） on human breast MCF-7cells. METHODS： The effect of PEITC on cell proliferation was evaluated by MTS. Flow cytometer with Annexin-V / PI double staining method and Hoechst staining method were utilized to observe the influence upon the rate of cellular apoptosis by PEITC. Intracellular ROS level was analysed with DCFH-DA fluorescence dye. Furthermore,the protein expression of p53 and Bax were examined by Western blotting. RESULTS： PEITC inhibited the proliferation of MCF-7 cells in a dose-dependent manner. The positive expression of Bax was higher than control group after treatment of MCF-7 cells with PEITC（ 15 μmol / L）. Besides,PEITC caused a rapid accumulation of ROS and reached a maximum value at 9 h. And,PEITC-induced apoptosis was prevented by N-acetylcysteine（ NAC,a ROS scavenging agent）. Also, NAC could prevent PEITC-induced p53 protein expression. CONCLUSION： PEITC effectively inhibits the cell growth via apoptosis pathway in MCF-7 cells. The effects might,at least partly,be obtained via ROS mediated p53 activation and its downstream signal pathway.