β-咔啉类生物碱对人胃癌SGC-7901细胞增殖、凋亡及PTEN/Akt表达的影响

Effect of β-carboline alkaloid on proliferation,apoptosis and expression levels of PTEN/Akt in human gastric cancer SGC-7901 cells

目的探讨β-咔啉类生物碱对人胃癌SGC-7901细胞增殖、凋亡及第10号染色体缺失的磷酸酶及张力蛋白同源基因(PTEN)/丝苏氨酸蛋白激酶(Akt)表达的影响。方法采用不同浓度β-咔啉类生物碱(0、10、20、40μg/ml)处理SGC-7901细胞后,应用活细胞计数试剂盒(CCK-8)法检测β-咔啉类生物碱处理24、48 h后的SGC-7901细胞增殖抑制情况,Hoechst 33258染色、琼脂糖凝胶电泳法观察β-咔啉类生物碱处理48 h后的细胞凋亡情况,荧光定量聚合酶链反应和Western blotting分别检测β-咔啉类生物碱(0、10、20、30、40μg/ml)处理48 h后细胞中PTEN、Akt m RNA和蛋白水平。结果β-咔啉类生物碱均能抑制人胃癌SGC-7901细胞的增殖,抑制率呈浓度依赖性(P<0.05);β-咔啉类生物碱可诱导人胃癌SGC-7901细胞凋亡,且伴有凋亡特有的DNA梯形条带;与0μg/ml相比,其余浓度β-咔啉类生物碱处理48 h后的PTEN m RNA和蛋白表达增加,而Akt m RNA和蛋白表达减少,差异均有统计学意义(P<0.05)。结论β-咔啉类生物碱可抑制人胃癌SGC-7901细胞增殖并诱导凋亡,可能与影响PTEN及Akt表达有关。

Objective To explore the effects of β-carboline alkaloid on the proliferation, apoptosis and expression levels of phosphatase and tensin homologue deleted on chromosome 10（ PTEN ）/serine-threonine kinase （Akt） in human gastric cancer SGC- 7901 cells. Methods SGC-7901 cells were treated with different concentrations of β-carboline alkaloid. Cell viability was measured by CCK-8 at 24 and 48 h after the treatment of β-carboline alkaloid（ 0, 10, 20, 40 p,g/ml）. Apoptosis morphological and biochemical changes were detected by Hoechst 33258 staining and agarose gel electroghoresis at 48 h after the treatment of β-carboline alkaloid, re- spectively. The mRNA and protein levels of PTEN and Akt were examined by quantitative reverse-transcription PCR and Western blot- ting at 48 h after the treatment of β-carboline alkaloid（0, 10, 20, 30, 40 p^g/ml）. Results β-carboline alkaloid effectively inhibited the proliferation of SGC-7901 cells in a concentration-dependent manner. β-carboline alkaloid could induce the apoptosis of SGC-7901 cells with the characteristic ladder pattern. Compared with 0 μg/ml, there were increased mRNA and protein levels of PTEN but de- creased mRNA and protein levels of Akt in other concentrations of β-earboline alkaloid with significant difference （P〈0. 05）. Conclu- sion β-earboline alkaloid inhibited the cell proliferation and induced cell apoptosis, with the possible mechanism of up-regulation of anti-apoptotic protein PTEN and down-regulation of apoptotic protein Akt.