Overcoming EMT-driven metastatic castration-resistant prostate cancer

摘要： 前列腺癌(PCA)最初发展于前列腺癌，可通过手术治愈 和放射治疗。前列腺癌的标准治疗选择是雄激素消融。 因为前列腺癌细胞的生存依赖于雄激素的供应。虽然这件事 治疗方法最初是有效的，PCA总是复发，对 激素疗法。然而，当癌症扩散到身体的其他部位时， 这种形式的复发癌症称为转移性去势抵抗前列腺癌 (CRPC)实际上是不治之症和致命的。因此，迫切需要发展 有效和安全的抗癌替代品，如从饮食到 成功控制CRPC。胡椒碱(Piperine，PIP)是一种天然生物碱，广泛存在于 胡椒香料有几种药理作用，包括抗癌活性。我们的 最近发表的文章首次表明，PIP抑制两种激素依赖 荷尔蒙非依赖性前列腺癌裸鼠模型的生长。重要的是，我们 研究表明，PIP下调雄激素受体(AR)的表达，导致 前列腺癌细胞中PSA水平降低。然而，PIP是否具有抗转移作用 CRPC单元格中的属性是未知的。我们随后的初步研究发现 PIP靶向翻译控制的肿瘤蛋白(TCTP)的转录， 一种促进CRPC细胞转移特性的抗凋亡蛋白。 PIP对TCTP的下调也导致肿瘤E-钙粘蛋白的激活 CRPC细胞中的抑制分子通过调节关键上皮细胞因子的表达 间充质转化(EMT)标记物如Snail-1和N-cadherin。基于 这些观察结果，我们的假设是，饮食中服用PIP可以抑制 靶向AR、TCTP和逆转EMT信号在CRPC中的转移进展 细胞。这一假设将在两个具体目标上得到检验。在目标1中，我们将确定 膳食给予PIP能否抑制或阻止C4-2B RFP的转移 和22Rv1 RFP细胞在裸鼠实验性静脉转移模型中。 在这些研究中，肿瘤转移将被用作终点。在研究结束时， 将收集转移性病变和各种器官进行组织病理学分析 确定PIP在肿瘤转移中的作用。TCTP、AR、α-SMA、 转移组织中纤维连接蛋白、蜗牛-1、N-钙粘蛋白、波形蛋白和E-钙粘蛋白的表达 样本也将通过免疫组织化学进行测定。在目标2中，我们将描述 PIP是否干扰AR和TCTP介导的EMT信号以恢复E-钙粘蛋白作为一种 体外模型中靶向转移的CRPC细胞的机制。在这个目标中，我们将使用 各种方法，如基因沉默，功能获得，药理学， 基于启动子和分子基础的检测方法研究其抗转移机制 皮普。在成功完成这些拟议的具体目标后取得的成果将 为开发PIP作为潜在的抗肿瘤转移药物提供有价值的信息 成功控制CRPC。

Summary: Prostate cancer (PCa) that initially develops in the prostate gland is curable by surgery and radiotherapy. The standard choice of treatment for PCa is by androgen ablation since PCa cells survive on the availability of androgen hormone. Although this treatment approach is effective initially, PCa recur invariably and do not respond to hormonal therapy. However when the cancer has spread to other parts of the body and such form of recurrent cancer known as metastatic castration-resistant prostate cancer (CRPC) is practically incurable and lethal. Hence, there is an urgent need to develop effective and safe anti-cancer alternatives such as compounds derived from diet to successfully control CRPC. Piperine (PIP), a natural alkaloid abundantly present in pepper spice has several pharmacological benefits including anti-cancer activity. Our recent publication for the first time showed that PIP inhibits both hormone-dependent and hormone-independent prostate tumor growth in nude mice model. Importantly, we showed that PIP down regulates the expression of androgen receptor (AR) resulting in the reduction of PSA levels in PCa cells. However, whether PIP has anti-metastatic properties in CRPC cells are not known. Our subsequent preliminary studies identified that PIP targets the transcription of Translationally Controlled Tumor Protein (TCTP), an anti-apoptotic protein that promotes the metastatic properties of CRPC cells. Downregulation of TCTP by PIP also results in the activation of E-cadherin, a tumor suppressor molecule in CRPC cells by modulating the expression of key epithelial to mesenchymal transition (EMT) markers such as snail-1 and N-cadherin. Based on these observations, our hypothesis is that dietary administration of PIP can inhibit metastasis development by targeting AR, TCTP and reversing EMT signaling in CRPC cells. This hypothesis will be tested in two specific aims. In Aim 1, we will determine whether dietary administration of PIP can inhibit or prevent metastasis of C4-2B RFP and 22Rv1 RFP cells in an experimental intravenous metastasis model of nude mice. In these studies, tumor metastasis will be used as end points. At the end of the study, metastatic lesions and various organs will be collected for histopathology analyses to determine the effects of PIP on metastasis. Expression of TCTP, AR, α-SMA, fibronectin, snail-1, N-cadherin, vimentin and E-cadherin in the metastatic tissue samples will also be determined by immunohistochemistry. In Aim 2, we will delineate whether PIP disrupts AR and TCTP-mediated EMT signaling to restore E-cadherin as a mechanism to target metastatic CRPC cells in an in vitro model. In this aim, we will use variety of approaches such as gene silencing, gain of function, pharmacological, promoter and molecular based assays to delineate the anti-metastatic mechanisms of PIP. Results obtained upon successful completion of these proposed specific aims will yield valuable information in developing PIP as a potential anti-metastatic agent in successfully controlling CRPC.