Regression of mouse prostatic intraepithelial neoplasia by nonsteroidal anti-inflammatory drugs in the transgenic adenocarcinoma mouse prostate model
Regression of mouse prostatic intraepithelial neoplasia by nonsteroidal anti-inflammatory drugs in the transgenic adenocarcinoma mouse prostate model
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DOI：
10.1158/1078-0432.ccr-04-0732
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发表时间：
2004-11-15
影响因子：
11.5
通讯作者：
Reddy, BS
中科院分区：
文献类型：
--
作者：
Narayanan, BA;Narayanan, NK;Reddy, BS
目的：流行病学研究表明，定期服用环氧化酶（考克斯）-2抑制剂（如阿司匹林或其他非甾体抗炎药（NSAID））的人群患结肠癌的风险降低。尽管选择性考克斯-2抑制剂塞来昔布和舒林酸的代谢产物依昔舒林作为结肠癌和前列腺癌的有效化学预防剂已获得越来越多的关注，但对潜在的分子靶点和机制知之甚少。此外，NSAID的副作用是大规模应用于预防人类癌症的主要障碍;例如，在美国，1998年有16，550人死于NSAID引起的胃肠道并发症。与这些化合物的毒性引起了人们的关注，更多的需要知道他们的作用模式和分子targets.Experimental设计：我们使用的转基因小鼠前列腺（TRAMP）模型，它表现出与人类前列腺癌，包括上皮起源的相似性，从PIN阶段发展到腺癌，转移的转基因，这是由雄激素调控。除了从组织学上分析TRAMP小鼠背外侧前列腺的PIN病变外，我们还描述了塞来昔布和依昔舒林对小鼠PIN病变的分子靶点和机制。我们对来自小鼠PIN病变组织的总蛋白裂解物进行Western印迹分析，以测量雄激素受体、血管内皮生长因子、核因子-κ B p65、Bcl II、AKT（总丝氨酸和磷酸化丝氨酸（473））、p53、细胞周期蛋白依赖性激酶抑制剂p21（WAF 1/CIP 1）、p27、BAX和半胱天冬酶-3来证明塞来昔布和依昔舒林抑制前列腺背外侧PIN病变的考克斯-2非依赖性机制。我们首次发现：（a）塞来昔布和依昔舒林作为膳食补充剂，分别在800和500 ppm剂量下，16周后对前列腺癌产生强烈的抑制作用;（B）治疗2周后背外侧前列腺的组织学分析表明，塞来昔B使PIN病变从75%减少到19%，而依昔舒林使PIN病变减少到16%;（c）更重要的是，塞来昔布或依昔舒林治疗组中的少数PIN和腺癌显示出更多的凋亡细胞、较低水平的增殖细胞核抗原和较低数量的有丝分裂细胞。为了了解参与抑制PIN病变的分子机制，首先，我们检测了参与血管生成和炎症过程的分子靶点的表达。对PIN病变前列腺背外侧组织的总蛋白裂解物进行Western印迹分析，结果清楚表明，塞来昔布更有效地下调了雄激素受体、血管内皮生长因子、核因子-κ B p65和Bcl II的表达。AKT蛋白下调塞来昔布的（总的和在Ser（473）磷酸化的）信号传导清楚地表明抑制存活基因和病理过程，否则可能导致腺癌。总的来说，这项研究的结果清楚地表明，塞来昔布和依昔舒林通过调节参与考克斯-2依赖性和-独立的机制。虽然这些药物已经在临床试验中或用作化学预防剂，但本研究的结果表明它们的作用方式不同，从而帮助我们了解副作用。
Purpose: Epidemiologic studies have revealed a decreased risk of colon cancer among people who have regularly taken cyclooxygenase (COX)-2 inhibitors such as aspirin or other nonsteroidal anti-inflammatory drugs (NSAIDs). Whereas the selective COX-2 inhibitor celecoxib and exisulind, a metabolic product of sulindac, have gained increasing attention as efficacious chemopreventive agents against colon and prostate cancer, not much is known about the underlying molecular targets and mechanisms. Moreover, the side effects of NSAIDs are a major obstacle for large-scale application to the prevention of cancer in humans; for example, in the United States in 1998, there were 16,550 deaths from NSAID-induced gastrointestinal complications. The toxicity associated with these compounds is raising concerns, and more needs to be known about their mode of action and molecular targets.Experimental Design: We used the transgenic mouse prostate (TRAMP) model, which exhibits similarities with human prostate cancer, including epithelial origin, progression from the PIN stage to adenocarcinoma, and metastasis by a transgene that is hormonally regulated by androgens. In addition to histologically analyzing the PIN lesions of the dorsolateral prostate from TRAMP mice, we delineated the molecular targets and mechanisms of celecoxib and exisulind against mouse PIN lesions. We performed Western blot analysis of the total protein lysate from the tissues of mouse PIN lesions to measure the level of expression of androgen receptor, vascular endothelial growth factor, nuclear factor-kappaB p65, BclII, AKT (total and phosphorylated Ser(473)), p53, cyclin-dependent kinase inhibitor p21(WAF1/CIP1), p27, BAX, and caspase-3 to demonstrate the COX-2-independent mechanism involved in the inhibition of PIN lesions of the dorsolateral prostate by both celecoxib and exisulind.Results: We found for the first time that (a) both celecoxib and exisulind as dietary supplements induce strong inhibitory effects against prostate cancer at doses of 800 and 500 ppm, respectively, after 16 weeks; (b) the histologic analysis of the dorsolateral prostate after 2 weeks of treatment indicated a reduction of PIN lesions from 75% to 19% with celecoxib and to 16% with exisulind; (c) more importantly, those few PINs and adenocarcinomas in the groups treated with celecoxib or exisulind showed more apoptotic cells, lower levels of proliferating cell nuclear antigen, and a lower number of mitotic cells. To understand the molecular mechanisms involved in the inhibition of PIN lesions, first, we examined the expression of molecular targets involved in angiogenesis and inflammatory processes. It was clearly evident from Western blot analysis of the total protein lysate derived from the dorsolateral prostate tissues with PIN lesions that expression of androgen receptor, vascular endothelial growth factor, nuclear factor-kappaB p65, and BclII is down-regulated more effectively by celecoxib. Down-regulation of AKT protein (total and phosphorylated at Ser(473)) signaling by celecoxib clearly indicates an inhibition of the survival gene and the pathological process that could otherwise lead to adenocarcinoma.Conclusions: Overall, the findings from this study clearly show the effectiveness of celecoxib and exisulind in reducing the PIN lesions by modulating a cascade of molecular targets involved in COX-2-dependent and -independent mechanisms. Whereas these agents are already in clinical trial or in use as chemopreventive agents, findings from this study demonstrate the difference in their mode of action, thus helping us to understand the side effects.