Autophagic cell death of human pancreatic tumor cells mediated by oleandrin, a lipid-soluble cardiac glycoside
Autophagic cell death of human pancreatic tumor cells mediated by oleandrin, a lipid-soluble cardiac glycoside
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DOI：
10.1177/1534735407309623
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发表时间：
2007-12-01
影响因子：
2.9
通讯作者：
Yang, Peiying
中科院分区：
文献类型：
--
作者：
Newman, Robert A.;Kondo, Yasuko;Yang, Peiying
脂溶性强心苷如蟾蜍灵、夹竹桃苷和洋地黄毒苷已被认为是可能用作抗癌剂的强效药剂。夹竹桃苷的研究进展。（夹竹桃科），已经显示通过诱导细胞凋亡来诱导细胞死亡。在人胰腺癌细胞系PANC-1细胞中，细胞死亡不是通过凋亡而是通过自噬发生。夹竹桃苷在低纳摩尔浓度下有效地抑制细胞增殖，并诱导深刻的G（2）/M细胞周期停滞。细胞周期的抑制并不伴随着任何显着的亚G1细胞的积累，这表明一个非凋亡机制。夹竹桃苷处理的细胞表现出时间和浓度依赖性染色与吖啶橙子，溶酶体染色。PANC-1细胞内的亚细胞变化包括线粒体浓缩和易位到核周位置伴随空泡。荧光夹竹桃素类似物（BODIPY夹竹桃素）的使用揭示了细胞线粒体内的药物的共定位。在自噬体结构内发现受损的线粒体。自噬体的形成通过电子显微镜和检测绿色荧光蛋白标记的轻链3与自噬体膜的结合来证实。还观察到药物介导的pAkt形成抑制和pERK上调。将Akt转染到PANC-1细胞中或通过MAPK抑制剂抑制pERK活化消除了夹竹桃苷介导的细胞生长抑制，表明pAkt的减少和pERK的增加对于夹竹桃苷抑制肿瘤细胞增殖的能力是重要的。这些数据提供了对一种有效的脂溶性强心苷（夹竹桃苷）在控制人胰腺癌增殖中的机制和作用的深入了解。
Lipid-soluble cardiac glycosides such as bufalin, oleandrin, and digitoxin have been suggested as potent agents that might be useful as anticancer agents. Past research with oleandrin, a principle cardiac glycoside in Nerium oleander L. (Apocynaceae), has been shown to induce cell death through induction of apoptosis. In PANC-1 cells, a human pancreatic cancer cell line, cell death occurs not through apoptosis but rather through autophagy. Oleandrin at low nanomolar concentrations potently inhibited cell proliferation associated with induction of a profound G(2)/M cell cycle arrest. Inhibition of cell cycle was not accompanied by any significant sub G1 accumulation of cells, suggesting a nonapoptotic mechanism. Oleandrin-treated cells exhibited time- and concentration-dependent staining with acridine orange, a lysosomal stain. Subcellular changes within PANC-1 cells included mitochondrial condensation and translocation to a perinuclear position accompanied by vacuoles. Use of a fluorescent oleandrin analog (BODIPY-oleandrin) revealed co-localization of the drug within cell mitochondria. Damaged mitochondria were found within autophagosome structures. Formation of autophagosomes was confirmed through electron microscopy and detection of green fluorescent protein-labeled light chain 3 association with autophagosome membranes. Also observed was a drug-mediated inhibition of pAkt formation and up-regulation of pERK. Transfection of Akt into PANC-1 cells or inhibition of pERK activation by MAPK inhibitor abrogated oleandrin-mediated inhibition of cell growth, suggesting that the reduction of pAkt and increased pERK are important to oleandrin's ability to inhibit tumor cell proliferation. The data provide insight into the mechanisms and role of a potent, lipid-soluble cardiac glycoside (oleandrin) in control of human pancreatic cancer proliferation.