Blocking Angiotensin II Type 1 Receptor Triggers Apoptotic Cell Death in Human Pancreatic Cancer Cells
Blocking Angiotensin II Type 1 Receptor Triggers Apoptotic Cell Death in Human Pancreatic Cancer Cells
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DOI：
10.1097/mpa.0b013e3181c314cd
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发表时间：
2010-07-01
期刊：
影响因子：
2.9
通讯作者：
Arafat, Hwyda A.
中科院分区：
文献类型：
--
作者：
Gong, Qiaoke;Davis, Molly;Arafat, Hwyda A.
目的：胰腺导管腺癌（PDA）是一种侵袭性恶性肿瘤，其年死亡率与其年发病率接近。我们最近证明血管紧张素II (AngII) 1型受体（AT1R）可能参与PDA血管生成。本研究评估了AT1R阻滞剂氯沙坦在不同p53突变状态的PDA细胞中的抗增殖和促凋亡作用。方法：采用流式细胞术分析细胞周期；膜联蛋白v -异硫氰酸荧光素（V-FITC）和末端脱氧转移酶（TdT）介导的dUTP镍端标记染色；实时聚合酶链反应和Western blotting检测信使RNA和蛋白质；比色法测定Caspase-3活性；荧光素酶测定启动子活性。结果：氯沙坦剂量依赖性降低细胞存活率，增加g1前期积累。它还增加了p53、p21、p27和Bax的表达，降低了Bcl-2和Bcl-xl的表达。在wtp53细胞中，氯沙坦增加了两种细胞系中p53的转录并激活了caspase-3。然而，其在mtp53细胞中的促凋亡作用主要依赖于caspase-3。结论：我们的数据描述了AT1R参与PDA细胞凋亡机制，并提供了氯沙坦刺激促凋亡信号通路的第一个证据，无论p53突变状态如何。由于p53功能的丧失在PDA患者中经常观察到，我们的数据表明AT1R阻断是控制PDA生长的一种新的治疗策略。
Objectives: Pancreatic ductal adenocarcinoma (PDA) is an aggressive malignancy with an annual mortality rate close to its annual incidence. We recently demonstrated that angiotensin II (AngII) type 1 receptor (AT1R) might be involved in PDA angiogenesis. This study evaluated the antiproliferative and proapoptotic effects of an AT1R blocker, losartan, in PDA cells with different p53 mutation status.Methods: Cell cycle was analyzed by flow cytometric analysis of DNA content; apoptosis by annexin V-fluorescein isothiocyanate (V-FITC) and terminal deoxytransferase (TdT)-mediated dUTP nick-end labeling staining; messenger RNA and protein by real-time polymerase chain reaction and Western blotting; caspase-3 activity by colorimetric assay; and promoter activity by luciferase assay.Results: Losartan dose-dependently decreased cell survival and increased their preG1 accumulation. It also increased p53, p21, p27, and Bax and reduced Bcl-2 and Bcl-xl expression. In wtp53 cells, losartan increased p53 transcription and activated caspase-3 in both cell lines. However, its proapoptotic effects in mtp53 cells were mainly caspase-3-dependent.Conclusion: Our data describe the involvement of AT1R in PDA cell apoptotic machinery and provide the first evidences that losartan stimulates the proapoptotic signaling pathways regardless of the p53 mutation status. As loss of p53 function is frequently observed in PDA patients, our data suggest AT1R blockade as a novel therapeutic strategy to control PDA growth.