Li Lin-Qiang, Li Xue-Lian, Wang Lu, Du Wei-Jie, Guo Rui, Liang Hai-Hai, Liu Xue, Liang De-Sen, Lu Yan-Jie, Shan Hong-Li, Jiang Hong-Chi
Key Laboratory of Hepatosplenic Surgery, Department of General Surgery, The First Affiliated Hospital of Harbin Medical University, Harbin, China.
Cell Physiol Biochem. 2012;30(3):631-41. doi: 10.1159/000341444. Epub 2012 Jul 27.
Matrine is one of the major alkaloids extracted from Sophora flavescens and has been used clinically for breast cancer with notable therapeutic efficacy in China. However, the mechanisms are still largely unknown.
Cell viability was analyzed by MTT assay. After MCF-7 cells were treated with matrine for 48h, apoptosis was detected by flow cytometry, TUNEL assay and transmission electron microscopy, and the cell cycle distribution was also analyzed by flow cytometry. Further, the expression of PTEN, pAkt, Akt, pBad, Bad, p21(/WAF1/CIP1), and p27(/KIP1) was determined by Western blot. Changes of miR-21 level were quantified by real-time RT-PCR. After miR-21 was transfected in MCF-7 cells, PTEN protein level was measured by Western blot.
Matrine inhibited MCF-7 cell growth in a concentration-and time-dependent manner, by inducing apoptosis and cell cycle arrest at G(1)/S phase. Matrine up-regulated PTEN by downregulating miR-21 which in turn dephosphorylated Akt, resulting in accumulation of Bad, p21(/WAF1/CIP1) and p27(/KIP1).
Our study unraveled, for the first time, the ability of matrine to suppress breast cancer growth and elucidated the miR-21/PTEN/Akt pathway as a signaling mechanism for the anti-cancer action of matrine. Our findings also reinforce the notion that miRNAs can act as mediators of the therapeutic efficacy of natural medicines.
苦参碱是从苦参中提取的主要生物碱之一，在中国已被临床用于治疗乳腺癌，具有显著的治疗效果。然而，其作用机制仍 largely 未知。
采用 MTT 法分析细胞活力。MCF-7 细胞经苦参碱处理 48 小时后，通过流式细胞术、TUNEL 法和透射电子显微镜检测细胞凋亡，并通过流式细胞术分析细胞周期分布。此外，通过 Western blot 检测 PTEN、pAkt、Akt、pBad、Bad、p21(/WAF1/CIP1)和 p27(/KIP1)的表达。通过实时 RT-PCR 定量 miR-21 水平的变化。在 MCF-7 细胞中转染 miR-21 后，通过 Western blot 检测 PTEN 蛋白水平。
苦参碱以浓度和时间依赖性方式抑制 MCF-7 细胞生长，通过诱导细胞凋亡和使细胞周期停滞在 G(1)/S 期。苦参碱通过下调 miR-21 上调 PTEN，进而使 Akt 去磷酸化，导致 Bad、p21(/WAF1/CIP1)和 p27(/KIP1)积累。
我们的研究首次揭示了苦参碱抑制乳腺癌生长的能力，并阐明了 miR-21/PTEN/Akt 途径作为苦参碱抗癌作用的信号机制。我们的发现还强化了 miRNA 可作为天然药物治疗效果介质的观点。
