N-乙酰半胱氨酸萝卜硫素通过上调Bak和下调Bcl-2蛋白表达诱导前列腺癌细胞凋亡

D,L-sulforaphane N-Acetyl-L-cysteine induces apoptosis by upregulating Bak and downregulating Bcl-2 in human prostate cancer cells

目的探究N-乙酰半胱氨酸萝卜硫素(D,L-sulforaphane N-Acetyl-L-cysteine,SFN-NAC)诱导前列腺癌细胞凋亡的分子机制。方法将前列腺癌细胞DU145和PC-3分别培养在6孔板中,当细胞密度达到70%-80%时,分别随机分为对照组(不加SFN-NAC)和加药组(加入终浓度为30μmol/L的SFN-NAC),继续在37℃培养24 h。利用AnnexinⅤ异硫氰酸荧光素/碘化丙啶(FITC/PI)双染流式细胞术检测细胞凋亡程度;利用Western blot检测Bak、Bax、Bcl-2和cleaved Caspase-3蛋白表达水平。结果与对照组相比,加药组的细胞凋亡率增高(P<0.01)。加药组细胞Bak蛋白表达较对照组升高(P<0.05);Bax蛋白表达也有少量增加,但与对照组相比,无统计学差异(P>0.05);Bcl-2蛋白表达下降(P<0.05);Bax/Bcl-2比值增加(P<0.01);细胞cleaved Caspase-3表达水平升高(P<0.01)。结论 N-乙酰半胱氨酸萝卜硫素通过上调Bak、下调Bcl-2蛋白表达,活化Caspase-3,诱导前列腺癌细胞凋亡,说明N-乙酰半胱氨酸萝卜硫素通过线粒体途径发挥抗癌作用。

Objective To investigate the mechanisms of apoptosis caused by D,L-sulforaphane N-Acetyl-L-cysteine（ SFN-NAC） in human prostate cancer cells. Methods Human prostate cancer cells DU145 or PC-3 were seeded in six-well plates. When the cell confluency reached 70%- 80%,they were randomly divided into control group（ no SFN-NAC treatment） and treatment group（ treated with 30 μmol / L SFN-NAC）. After 24 h incubation at 37 ℃,the apoptosis was assessed by FITC-Annexin Ⅴ / PI staining,the expression levels of Bak,Bax,Bcl-2 and cleaved Caspase-3 were detected by Western blot. Results The rate of apoptosis in treatment group was significantly higher than that in control group（ P〈0. 01）. Compared with control group,the expression of Bak significantly increased in treatment group（ P〈0. 05）,and the expression of Bax increased slightly,but there was no statistical difference（ P〉0. 05）. The expression of Bcl-2 in treatment group significantly reduced（ P〈0. 05）,while the rate of Bax / Bcl-2 and the expression of cleaved Caspase-3 were significantly increased（ P〈0. 01）. Conclusion SFN-NAC could induce the apoptosis by upregulating Bak and downregulating Bcl-2 in human prostate cancer cells,indicating that SFN-NAC play a role in anti-cancer through the mitochondriamediated pathway.