Objective: To investigate the effect of solasonine, an active component of Solanum nigrum, on proliferation and apoptosis of non-small cell lung cancer PC9 cells.
Methods: PC9 cells were treated with 2, 5, 10, 15, 20, or 25 μmol/L solasonine, and the changes in cell proliferation were examined using CCK-8 assay. Tetramethyl rhodamine ethyl ester (TMRE) was used to detect the changes in mitochondrial membrane potential, and caspase-3/7 detection kit and GreenNucTM caspase-3/Annexin V-mCherry kit for live cell were used to analyze the changes in caspase-3 of the cells. Annexin V-FITC/PI double staining was employed to analyze the apoptosis rate of the cells. The effect of PTEN inhibitors on solasonine-induced cell apoptosis was examined by detecting apoptosis-related protein expressions using Western blotting.
Results: Solasonine treatment for 24, 48, and 72 h significantly lowered the viability of PC9 cells. The cells treated with solasonine for 24 h showed significantly decreased mitochondrial membrane potential and increased cell apoptosis with enhanced caspase-3/7 and caspase-3 activities and expression of cleaved caspase-3. Solasonine treatment significantly decreased phosphorylation levels of PI3K and Akt, increased the protein expressions of PTEN and Bax, and lowered the expression of Bcl-2 protein in the cells.
Conclusion: Solasonine inhibits proliferation and induces apoptosis of PC9 cells by regulating the Bcl-2/Bax/caspase-3 pathway and its upstream proteins.
目的: 探讨龙葵活性成分澳洲茄碱对非小细胞肺癌细胞PC9增殖、凋亡的影响。
方法: 体外培养PC9细胞，设对照组（0 μmol/L）及澳洲茄碱不同剂量组（0、2、5、10、15、20、25 μmol/L），CCK-8试剂盒检测澳洲茄碱对PC9细胞的增殖抑制作用；TMRE检测线粒膜电位；caspase3/7活性试剂盒联合GreenNuc™ Caspase-3/Annexin V-mCherry染色检测caspase-3活性；Annexin V-FITC/PI双染法检测细胞凋亡率；给药处理或者使用PTEN抑制剂后，Western blot检测细胞中相关蛋白的表达量。
结果: 与对照组相比，经澳洲茄碱干预24、48、72 h后，PC9细胞的活力均明显降低（P<0.05）；经澳洲茄碱干预24 h后，细胞线粒体膜电位明显降低，而细胞凋亡比例明显升高（P<0.05）；caspase-3/7活力、活细胞Caspase-3活性及cleaved caspase-3蛋白表达均显著升高（P<0.01）；PI3K和Akt磷酸化水平降低（P<0.05）；而PTEN、Bax蛋白表达上调（P<0.05）；抗凋亡蛋白Bcl-2蛋白的表达下调（P<0.05）。
结论: 澳洲茄碱可通过调控Bcl-2/Bax/caspase-3通路及其上游蛋白活性而抑制PC9细胞增殖，促进其凋亡。
Keywords: Bcl-2/Bax/caspase-3 signaling pathway; apoptosis; homologous phosphatase tensin protein; lung cancer; solasonine.