Investigation of extrinsic and intrinsic apoptosis pathways of new clerodane diterpenoids in human prostate cancer PC-3 cells
Investigation of extrinsic and intrinsic apoptosis pathways of new clerodane diterpenoids in human prostate cancer PC-3 cells
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DOI：
10.1016/j.ejphar.2004.09.040
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发表时间：
2004-10-25
影响因子：
5
通讯作者：
Guh, JH
中科院分区：
文献类型：
--
作者：
Huang, DM;Shen, YC;Guh, JH
在我们继续寻找从天然产物中发现生物活性化合物的过程中，我们从Casearia membranacea中分离出六种新的clerodane二萜，caseamembrins A至F，并在人类耐药前列腺癌PC-3细胞中检测了它们的抗增殖活性。所有这些化合物显示出有效的抗增殖活性，使用磺酰罗丹明B测定和诱导细胞凋亡的末端脱氧核苷酸转移酶（TdT）dUTP缺口末端标记（TUNEL）反应技术。数据表明，酪蛋白C是这些克罗烷二萜类化合物中最有效的化合物。酪蛋白C诱导Bcl-2和Bcl-xL表达下调，而促凋亡蛋白Mcl-1 S（短链）表达上调，提示这些Bcl-2家族成员蛋白可能在仲裁细胞凋亡中发挥作用。Caseamembrin C还诱导Fas配体（FasL）表达上调，caspase-8和caspase-9的裂解和激活，以及执行体caspase-3的Bid裂解和激活。然而，z-IETD-FMK（Z-Ile-Glu-Thr-Asp-fluoromethyl ketone，一种选择性caspase-8抑制剂）几乎完全抑制酪蛋白C诱导的Bid切割，而不改变caspase-9的活化，表明FasL/caspase-8/Bid级联的外源性途径在凋亡信号传导中仅起次要作用。提示酪蛋白C诱导的细胞凋亡主要是通过下调Bcl-2和Bcl-xL的表达，上调Mcl-IS蛋白的表达，激活caspase-9和caspase-3，激活内源性凋亡途径。(C)2004 Elsevier B. V.保留所有权利。
In our continuing search to discover bioactive compounds from natural products, we isolated six new clerodane diterpenes, caseamembrins A to F, from Casearia membranacea and examined their antiproliferative activities in human hormone-resistant prostate cancer PC-3 cells. All of these compounds displayed effective antiproliferative activity using sulforhodamine B assays and induced cell apoptosis by a terminal deoxynucleotidyl transferase (TdT) dUTP nick-end labeling (TUNEL)-reaction technique. The data demonstrated that caseamembrin C was the most effective compound among these clerodane diterpenoids. Caseamembrin C induced down-regulation of Bcl-2 and Bcl-xL expression, while up-regulation of proapoptotic protein Mcl-1S (short chain), suggesting that these Bcl-2 family member proteins may play a role on arbitrating the apoptotic cell death. Caseamembrin C also induced the up-regulation of Fas ligand (FasL) expression, cleavage and activation of caspase-8 and caspase-9, Bid cleavage and activation of executor caspase-3. However, z-IETD-FMK (Z-Ile-Glu-Thr-Asp-fluoromethyl ketone, a selective caspase-8 inhibitor) almost completely inhibited caseamembrin C-induced Bid cleavage without any modification of caspase-9 activation, indicating that the extrinsic pathway of FasL/caspase-8/Bid cascade only played a minor role in the apoptotic signaling. Taken together, it is suggested that caseamembrin C-induced apoptosis is predominantly through the activation of intrinsic apoptosis pathways by causing the down-regulation of Bcl-2 and Bcl-xL expression, up-regulation of Mcl-IS protein and activation of caspase-9 and caspase-3. (C) 2004 Elsevier B.V. All rights reserved.