Department of Hepatobiliary and Pancreatic Surgery, the First Clinical Hospital, Jilin University, Jilin, China.
Molecules. 2012 Sep 26;17(10):11435-46. doi: 10.3390/molecules171011435.
Researchers have proposed that VAA-I, a specific plant lectin found in Viscum album, has therapeutic effects on cancer and autoimmune diseases. VAA-I has shown some promising treatment results in some types of tumor cell lines, especially SMMC-7721 cells (human hepatocellular carcinoma cells). However, few details are known about the mechanism and process of cell death induced by VAA-I in tumor cells. In this study, the cell morphology results showed that SMMC-7721 cells treated with VAA-I exhibited several features typical of apoptotic cell death, which was confirmed by the Caspase inhibition assay. Fluo-3-acetoxymethyl ester (AM) fluorescence imaging techniques showed that rVAA-I significantly elevated the intracellular calcium level ([Ca2+]i) in SMMC-7721 cells. These findings suggest that apoptosis may play the most important role in SMMC-7721 cell death induced by rVAA-I. Finally, in the SMMC-7721 cells treated with rVAA-I, a series of genes in the p38 mitogen-activated protein kinase (MAPK) signaling pathway were expressed differentially, and further found that PI 3-kinase pathway is involved in rVAA-I signal transduction in SMMC-7721 cells.
研究人员提出，槲寄生中一种特定的植物凝集素 VAA-I 对癌症和自身免疫性疾病具有治疗作用。VAA-I 在某些类型的肿瘤细胞系中显示出一些有希望的治疗结果，特别是 SMMC-7721 细胞（人肝癌细胞）。然而，关于 VAA-I 在肿瘤细胞中诱导细胞死亡的机制和过程知之甚少。在这项研究中，细胞形态学结果表明，用 VAA-I 处理的 SMMC-7721 细胞表现出几种典型的凋亡细胞死亡特征，这通过 Caspase 抑制测定得到了证实。Fluo-3-乙酰氧甲酯（AM）荧光成像技术显示，rVAA-I 显著升高了 SMMC-7721 细胞中的细胞内钙离子水平([Ca2+]i)。这些发现表明，凋亡可能在 rVAA-I 诱导的 SMMC-7721 细胞死亡中起最重要的作用。最后，在用 rVAA-I 处理的 SMMC-7721 细胞中，p38 丝裂原活化蛋白激酶（MAPK）信号通路中的一系列基因表达差异，进一步发现 PI 3-激酶通路参与了 rVAA-I 在 SMMC-7721 细胞中的信号转导。
