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

描述（由申请人提供）： Licofelone（ML-3000）是一种新的和最令人感兴趣的化合物，是考克斯和5-LOX酶的平衡和竞争性抑制剂，并已被证明具有有效的抗炎活性。最近的研究报道了饮食中的利克非龙作为结肠癌和乳腺癌化学预防的抗癌剂的潜在效用。我们首次证明了甘草黄酮介导的考克斯-2和5-LOX抑制可诱导细胞凋亡，并降低PCa细胞增殖。此外，我们还观察到利卡非隆在转录水平下调了几个关键的促炎基因靶点，如PCa细胞中的NF-：Bp 65、VEGF和TNF 1。也有报道称，甘草非隆通过不依赖于花生四烯酸的线粒体途径诱导结肠癌细胞凋亡。然而，迄今为止，尚未研究利卡非龙对PCa的体内抗肿瘤发生功效或机制。因此，在前列腺癌动物模型中建立利可非龙的疗效和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剂的使用是非常关键的。我们假设双重考克斯/LOX抑制剂licofelone通过作用于广谱抗癌机制来预防PCa，除了或独立于考克斯/LOX酶抑制，所述抗癌机制包括调节炎性途径介质、抑制肿瘤血管生成、诱导细胞周期停滞和半胱天冬酶介导的细胞凋亡。鉴于审查者表达的具体问题，我们取消了细胞培养研究和异种移植模型。在本修订申请中，为了验证我们的假设，我们现在建议采用Noble（NBL）大鼠PCa模型，其中联合激素方案治疗有助于慢性炎症，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）从恶性病变的特定显微区域获取癌细胞用于RNA提取，和聚焦于通路的微阵列（GEArrays）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，即甘草黄酮具有调节多种抗癌药物的潜力。预防前列腺癌发生的机制途径。这项拟议的研究与NCI计划公告# PAR-08-055，癌症预防研究小额资助计划（R 03）的范围一致。考虑到其与传统NSAID相比具有优异的安全性，licofelone在癌症化学预防的临床研究中为预防性干预提供了巨大的潜力，同时最大限度地减少了毒性。

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.