Ramachandran Cheppail, Nair P K Raveendran, Alamo Arturo, Cochrane Curtis Bruce, Escalon Enrique, Melnick Steven J
Division of Hematology/Oncology, Research Institute, Miami Children's Hospital, FL 33155, USA.
Int J Cancer. 2006 Nov 15;119(10):2443-54. doi: 10.1002/ijc.22174.
Amooranin (AMR), a natural triterpenoid drug isolated and characterized from Amoora rohituka stem bark, is cytotoxic to SW620 human colon carcinoma cell line with an IC(50) value of 2.9 microg/ml. This novel compound caused depolarization of mitochondrial membrane and decrease of membrane potential, indicating initial signal of apoptosis induction. The percentage of cells with decreased mitochondrial potential ranged from 7.4% at 1 microg/ml to 60.5% at 100 microg/ml AMR. Flow cytometric analysis of apoptosis using Annexin-V-FITC staining showed that the percentage of apoptotic cells ranged from 7.5% at 1 microg/ml to 59.2% at 100 microg/ml AMR. AMR-induced apoptosis was accompanied by redistribution of cytochrome c from mitochondria to cytosol as well as down regulation of Bcl-2 and Bcl-X(L) proteins in a dose-dependent manner. SW620 human colon carcinoma xenograft mice treated with AMR showed significant reduction in tumor growth rates compared to saline- and doxorubicin-treated groups. The reduction in tumor growth rate was better in xenografts treated with 2 mg/kg AMR than 5 and 10 mg/kg treated mice. The analysis of global gene expression changes induced by AMR in xenograft tumors by microarray hybridization revealed that several genes involved in energy pathways, transport, apoptosis, immune response, nucleic acid metabolism, protein metabolism, cell growth and/or maintenance, signal transduction and cell communication, were affected by this natural cancer drug. These results suggest that the anticancer properties of AMR in SW620 human colon carcinoma cell line are mediated through its effects on functional genomics, targeting the apoptotic process.
阿莫拉宁（AMR）是一种从印度桃花心木茎皮中分离并鉴定出的天然三萜类药物，对SW620人结肠癌细胞系具有细胞毒性，IC（50）值为2.9微克/毫升。这种新型化合物导致线粒体膜去极化并降低膜电位，表明诱导凋亡的初始信号。线粒体电位降低的细胞百分比在1微克/毫升的AMR时为7.4%，在100微克/毫升时为60.5%。使用膜联蛋白-V-异硫氰酸荧光素染色进行凋亡的流式细胞术分析表明，凋亡细胞的百分比在1微克/毫升的AMR时为7.5%，在100微克/毫升时为59.2%。AMR诱导的凋亡伴随着细胞色素c从线粒体向细胞质的重新分布以及Bcl-2和Bcl-X（L）蛋白的剂量依赖性下调。与生理盐水和阿霉素治疗组相比，用AMR治疗的SW620人结肠癌异种移植小鼠的肿瘤生长速率显著降低。用2毫克/千克AMR治疗的异种移植瘤的肿瘤生长速率降低比用5和10毫克/千克治疗的小鼠更好。通过微阵列杂交分析AMR在异种移植瘤中诱导的全局基因表达变化，发现几个参与能量途径、转运、凋亡、免疫反应、核酸代谢、蛋白质代谢、细胞生长和/或维持、信号转导和细胞通讯的基因受到这种天然抗癌药物的影响。这些结果表明，AMR在SW620人结肠癌细胞系中的抗癌特性是通过其对功能基因组学的影响介导的，靶向凋亡过程。
