SM－1通过激活前胱天蛋白酶－3诱导人胃腺癌BGC－823细胞凋亡发挥抗肿瘤作用

目的：探讨前胱天蛋白酶（ procaspase）－3激活剂SM－1体内外对人胃癌BGC－823细胞的抗肿瘤作用及初步机制。方法体外MTT法测定SM－1对BGC－823细胞增殖的抑制作用，流式细胞仪分析不同浓度SM－1对BGC－823细胞凋亡率的影响，分别用Western印迹和RT－PCR测定SM－1对胱天蛋白酶（ caspase）－3蛋白和procaspase－3 mRNA表达的影响，采用裸鼠皮下移植瘤模型评价SM－1体内抗肿瘤作用。结果 SM－1体外呈剂量依赖性地抑制BGC－823细胞增殖并诱导其凋亡；SM－1暴露48 h 后， caspase－3蛋白和 procaspase－3 mRNA 表达水平增加；在300 mg／kg剂量下，SM－1对BGC－823皮下移植瘤生长具有明显的抑制作用，其抑制率达到56．3％（ P＜0．05）。结论 SM－1体内外对BGC－823细胞及皮下移植瘤具有较好的抑制作用，其机制主要通过激活procaspase－3诱导肿瘤细胞凋亡发挥抗肿瘤作用。

SM-1 induces apoptosis of BGC-823 cells by activating procaspase-3 and exerts antitumor effect

Objective To investigate the antitumor activity of the procaspase-3 activator SM-1 in BGC-823 cells in vivo and in vitro and the mechanisms.Methods The inhibitory effects of SM-1 on proliferation of BGC-823 cells were evaluated using MTT method, the cell apoptosis rate was detected by flow cytometry, and the expression of caspase-3 protein and procaspase-3 mRNA was detected by Western blotting and RT-PCR, respectively.SM-1 Antitumor activity was evaluated using the xenograft of BGC-823 cells in nude mice.Results SM-1 effectively inhibited the proliferation in vitro and in-duced apoptosis of BGC-823 cells in a dose-dependent manner.After treatment with SM-1 for 48 h, the protein expression levels of caspase-3 and mRNA expression levels of procaspase-3 were increased.SM-1 significantly inhibited growth of BGC-823 xenograft tumor at the 300 mg/kg dose and the inhibition rate was 56.3%(P<0.05).Conclusion SM-1 can significantly inhibit the tumor growth of BGC-823 cells in vivo and in vitro.The mechanism is possibly related to the activation of procaspase-3 and induced apoptosis of tumor cells.