Anti-cancer mechanisms of COX/LOX inhibitor licofelone on prostate carcinogenesis

描述(由申请人提供)： 利可酮(ML-3000)是一种新的、最有趣的化合物，是COX和5-LOX酶的平衡和竞争性抑制剂，已被证明具有强大的抗炎活性。最近的研究报道了饮食中的利洛酮作为结肠癌和乳腺癌化学预防的抗癌剂的潜在用途。我们首次证明了地塞米松介导的COX-2和5-LOX抑制诱导了细胞凋亡，并抑制了PCa细胞的增殖。此外，我们还观察到利福酮在转录水平下调了前列腺癌细胞中几个关键的促炎基因靶点，如核因子-：Bp65、血管内皮生长因子和肿瘤坏死因子1。也有报道称，利福酮通过线粒体途径诱导结肠癌细胞凋亡，而不依赖于花生四烯酸。然而，到目前为止，利福酮对前列腺癌的体内抗肿瘤作用或机制尚未被研究。因此，在前列腺癌动物模型中确定利洛酮的疗效并了解其潜在的作用模式，对于促进其作为潜在的化学预防或治疗药物的使用是非常关键的。我们假设，双重COX/LOX抑制剂利福酮通过作用于广泛的抗癌机制来预防PCa，包括调节炎症途径介质，抑制肿瘤血管生成，诱导细胞周期停滞和caspase介导的凋亡，以及COX/LOX酶抑制之外的或不依赖于COX/LOX酶抑制。鉴于审查者表达的具体关切，我们取消了细胞培养研究和异种移植模型。在这个修订的应用中，为了验证我们的假设，我们现在提议使用Noble(NBL)大鼠PCA模型，在该模型中，激素方案的组合治疗导致慢性炎症，导致启动、肿瘤转化和前列腺癌发生，并被广泛用于干预研究。我们还提出了新颖和创新的技术，例如使用激光捕获显微切割(LCM)从恶性病变的特定微观区域获取癌细胞以提取RNA，以及使用路径聚焦微阵列(GEArray)来确定改变的基因和转录因子的表达，这将提供关键信息来支持我们的假设，即利洛酮具有调节多个抗癌机制途径的潜力，以防止前列腺癌的发生。这项拟议的研究与NCI的计划公告#PAR-08-055，癌症预防研究小额资助计划(R03)的范围一致。与传统的非甾体抗炎药相比，利洛酮具有良好的安全性，在癌症化学预防的临床研究中提供了预防干预的巨大潜力，同时将毒性降至最低。

DESCRIPTION (provided by applicant): Licofelone (ML-3000), a new and most interesting compound, is a balanced and competitive inhibitor of both COX and 5-LOX enzymes and has been demonstrated for its potent anti-inflammatory activity. Recent studies have reported on the potential utility of dietary licofelone as an anti-cancer agent for colon and breast cancer chemoprevention. We have demonstrated for the first time that licofelone-mediated COX-2 and 5-LOX inhibition induced apoptosis, and reduced PCa cell proliferation. In addition, we have also observed that licofelone down-regulated several key pro-inflammatory gene targets at the transcription level, such as NF- :Bp65, VEGF and TNF1 in PCa cells. It has also been reported that licofelone induces apoptosis in colon cancer cells through the mitochondrial pathway independent of arachidonic acid. However, to date, the in vivo anti-tumorigenic efficacy or mechanism of licofelone against PCa has not been investigated. Therefore, establishing the efficacy and understanding the underlying mode of action of licofelone in animal models of prostate cancer is very critical for promoting its use as a potential chemopreventive or therapeutic agent. We hypothesize that the dual COX/LOX inhibitor licofelone prevents PCa by acting on a broad- spectrum of anti- cancer mechanisms, including modulation of inflammatory pathway mediators, inhibition of tumor angiogenesis, induction of cell cycle arrest and of caspase-mediated apoptosis, in addition to, or independent of, COX/LOX enzyme inhibition. In view of specific concerns expressed by the reviewers, we have eliminated the cell culture studies and the xenograft model. In this revised application, to test our hypothesis, we now propose to employ a Noble (NBL) rat PCa model in which a combined hormonal regimen treatment that contributes to chronic inflammation leading to initiation, neoplastic conversion and prostate carcinogenesis and is being widely used for intervention studies. We have also proposed novel and innovative technologies, such as use of laser capture microdissection (LCM) for the procurement of cancer cells from specific microscopic regions of malignant lesions for RNA extraction, and pathway-focused microarrays (GEArrays) to determine the expression of altered genes and transcription factors that will provide crucial information to support our hypothesis that licofelone has the potentials to modulate multiple anticancer mechanistic pathways to prevent prostate carcinogenesis. This proposed study is consistent with the scope of the NCI's Program Announcement # PAR-08-055, Cancer Prevention Research Small Grant Program (R03). Considering its excellent safety profile in contrast to the conventional NSAIDs, licofelone offers great potential for preventive interventions in clinical studies for cancer chemoprevention, while minimizing toxicity.