Department of Laboratory Medicine, The First Hospital of China Medical University, Shenyang, Liaoning 110001, PR China.
Mol Med Rep. 2012 May;5(5):1256-60. doi: 10.3892/mmr.2012.798. Epub 2012 Feb 20.
Sinomenine (SIN) is a bioactive component derived from a Chinese medicinal plant. Our previous studies demonstrated that SIN has cytotoxic effects on human lung cancer cells. However, the antitumor molecular mechanisms of SIN have yet to be elucidated in detail. In the present study, we further explored the effects of SIN on NCI-H460 human lung cancer cell viability and apoptosis and investigated the regulation and function of PI3K/Akt and ERK signaling pathways during SIN-induced apoptosis in various lung cancer cell lines. NCI-H460 cells were incubated with 200 µg/ml SIN for the indicated times (0, 24, 48 or 72 h). Cell viability was assessed by MTT assay. Akt, p-Akt, ERK1/2 and p-ERK1/2 protein levels were detected by western blotting, respectively. Two different selective inhibitors (LY294002 for the PI3K pathway; PD98059 for the MEK/ERK pathway) were used to characterize the relative roles of PI3K/Akt and ERK in SIN-induced apoptosis. Apoptosis was determined by flow cytometry. SIN inhibited the proliferation of NCI-H460 cells in a time-dependent manner, which was accompanied with significant activation of pAkt and pERK. LY294002 and PD98059 both significantly increased SIN-induced apoptosis in NCI-H460, NCI-H226 and NCI-H522 cells. Our findings suggest that the activation of the PI3K/Akt and ERK signaling pathways antagonize SIN-induced lung cancer cell apoptosis and molecules that inhibit these pathways should potentiate the effects of SIN. This study represents a significant step forward in our understanding of the signal transduction pathways associated with the apoptosis elicited by SIN.
青藤碱（SIN）是一种从中药植物中提取的生物活性成分。我们之前的研究表明，SIN 对人肺癌细胞具有细胞毒性作用。然而，SIN 的抗肿瘤分子机制尚未得到详细阐明。在本研究中，我们进一步探讨了 SIN 对 NCI-H460 人肺癌细胞活力和凋亡的影响，并研究了在不同肺癌细胞系中 SIN 诱导凋亡过程中 PI3K/Akt 和 ERK 信号通路的调节和功能。将 NCI-H460 细胞用 200μg/ml SIN 孵育不同时间（0、24、48 或 72 h）。通过 MTT 测定法评估细胞活力。通过 Western blot 分别检测 Akt、p-Akt、ERK1/2 和 p-ERK1/2 蛋白水平。使用两种不同的选择性抑制剂（PI3K 通路的 LY294002；MEK/ERK 通路的 PD98059）来表征 PI3K/Akt 和 ERK 在 SIN 诱导凋亡中的相对作用。通过流式细胞术测定凋亡。SIN 呈时间依赖性抑制 NCI-H460 细胞的增殖，同时显著激活 pAkt 和 pERK。LY294002 和 PD98059 均显著增加了 NCI-H460、NCI-H226 和 NCI-H522 细胞中 SIN 诱导的凋亡。我们的研究结果表明，PI3K/Akt 和 ERK 信号通路的激活拮抗 SIN 诱导的肺癌细胞凋亡，抑制这些通路的分子应该增强 SIN 的作用。这项研究代表了我们对 SIN 诱导的细胞凋亡相关信号转导通路理解的重要一步。
