Macrophage-lnduced Inflammation in High Fat Diet Enhanced Breast Cancer (Proj 4)

摘要 大多数乳腺癌(Brca)的发展在很大程度上受到非遗传因素的影响，如高脂饮食(HFD)导致的肥胖。高脂诱导的肥胖与BRCA风险相关的病理生理机制包括炎症过程；脂肪组织巨噬细胞(M-Phi-S)是炎症的主要贡献者，但它们在高脂诱导的BRCA中的具体作用尚无系统评估。膳食化合物由于其低毒性和针对炎症的能力而引起人们的兴趣；然而，在高脂饲料增强的BRCA中，对其有效性和作用机制的了解存在着根本的差距(S)。长期目标是开发抗炎的类黄酮胶，作为一种临床可测试的饮食方案，以延迟和/或预防HFD增强的BRCA。这项研究的目的是评估M-Phi-S是否是Quercetin在高脂蛋白增强型BRCA中抗炎作用的靶点，并确定这些作用是否通过sirtuin 1(Sirtuin 1)介导。中心假说是，在HFD增强的BRCA中，Quercetin调节M-Phi诱导的炎症的作用机制是通过SIRTL介导的。这一假说是基于申请人实验室的几条趋同的证据而提出的。这项拟议研究的基本原理是，阐明槲皮素的靶标及其在调节这些靶标中的作用机制将转化为一种更有效的预防/治疗HFD增强型BRCA的方法。这一假说将通过追求三个特定的目标来验证：1)阐明槲皮素对高脂饮食增强型BRCA炎症的阶段性影响；2)评估M-Phi-S是否是Qetetin在HFD增强型BRCA中抗炎作用的靶点；以及3)确定SIRT1是否是Quercetin在调节M-Phi诱导的HFD增强型BRCA炎症反应中的中介作用。在第一个目标下，BRCA的C3(1)SV40Tag小鼠模型将被用来确定Quercetin对炎症、随后的肿瘤形成和总存活率的阶段特异性影响。在第二个目标下，将使用体内M-Phi操纵技术，如将BRCA的C3(1)Tag转基因小鼠模型与MCP-1基因敲除小鼠杂交，以产生M-Phi缺陷的BRCA小鼠模型。这将有助于确定M-Phi-S在高脂饲料增强的BRCA中槲皮素的益处上所起的作用。最后，在目标3下，将使用SIRT1操纵技术来检验SIRT1作为Quercetin在HFD增强的BRCA中M-Phi诱导的炎症反应中的中介作用。这项拟议研究的创新之处在于研究了SIRT1作为生物活性膳食成分槲皮素在调节HFD增强型BRCA中M-Phi诱导的炎症中的益处的中介作用。这项拟议的研究意义重大，因为它通过使用饮食食物成分来靶向炎症，从而预防HFD增强型BRCA的发生和进展，炎症是这种疾病的机制核心。

ABSTRACT The development of the majority of breast cancers (BrCAs) is largely influenced by non-genetic factors such as high fat diet (HFD) induced obesity. The pathophysiological mechanisms that link HFD-induced obesity to BrCA risk include inflammatory processes; adipose tissue macrophages (M-Phi-s) are primary contributors to inflammation however there has been no systematic evaluation of their specific role in HFD-enhanced BrCA. Dietary compounds are of interest given their low toxicity profiles and their ability to target inflammation; however there is a fundamental gap in the understanding of their effectiveness and their mechanism(s) of action in HFD-enhanced BrCA. The long-term goal is to develop the anti-inflammatory flavonoid quercetin as a clinically testable dietary regimen to delay and/or prevent HFD-enhanced BrCA. The objective in this particular investigation is to evaluate whether M-Phi-s are a target for the anti-inflammatory effects of quercetin in HFD-enhanced BrCA and to determine if these effects are mediated through sirtuin 1 (SIRT1). The central hypothesis is that the mechanism of action of quercetin on the regulation of M-Phi-induced inflammation in HFD-enhanced BrCA is mediated through SIRTL This hypothesis has been formulated on the basis of several converging lines of evidence from the applicants' laboratory. The rationale for the proposed research is that elucidating the targets of quercetin and their mechanism of action in the regulation of these targets will translate to a more effective prevention/treatment approach in HFD-enhanced BrCA. This hypothesis will be tested by pursuing three specific aims: 1) Elucidate the stage-specific effects of quercetin on inflammation in HFD-enhanced BrCA; 2) Evaluate whether M-Phi-s are a target for the anti-inflammatory effects of quercetin in HFD-enhanced BrCA; and 3) Determine whether SIRT 1 is a mediator of the effects of quercetin in the regulation of M-Phi-induced inflammation in HFD-enhanced BrCA. Under the first aim, the C3(1)SV40Tag mouse model of BrCA, that will be fed a HFD to induce obesity, will be used to determine the stage-specific effects of quercetin on inflammation and subsequent tumorigenesis and overall survival. Under the second aim, in vivo M-Phi manipulation techniques will be used such as crossing the C3(1)Tag transgenic mouse model of BrCA with a MCP-1 knockout mouse to generate a M-Phi deficient mouse model of BrCA. This will help determine the role of M-Phi-s on the benefits of quercetin in HFD-enhanced BrCA. Finally, under aim 3, SIRT1 manipulation techniques will be used to examine the role of SIRT1 as a mediator of the effects of quercetin on M-Phi-induced inflammation in HFD-enhanced BrCA. The innovation of the proposed investigation is anchored in the examination of SIRT1 as a mediator of the benefits of the bioactive dietary component quercetin in the regulation of M-Phi-induced inflammation in HFD-enhanced BrCA. The proposed investigation is significant as it addresses prevention of incidence and progression of HFD-enhanced BrCA by using a dietary food component to target inflammation that is at the mechanistic core of this disease.