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）引起的肥胖。将HFD诱导的肥胖与BrCA风险联系起来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，但尚未对其在HFD增强的BrCA中的特定作用进行系统评价。鉴于其低毒性特征和靶向炎症的能力，膳食化合物是令人感兴趣的;然而，在理解其有效性及其在HFD增强的BrCA中的作用机制方面存在根本性差距。长期目标是开发抗炎类黄酮槲皮素作为临床可测试的饮食方案，以延迟和/或预防HFD增强的BrCA。本研究的目的是评估M-Phi-s是否是HFD增强BrCA中槲皮素抗炎作用的靶点，并确定这些作用是否通过sirtuin 1（SIRT 1）介导。中心假设是，槲皮素对HFD增强的BrCA中M-Phi诱导的炎症的调节的作用机制是通过SIRTL介导的。拟议研究的基本原理是阐明槲皮素的靶点及其在调节这些靶点中的作用机制将转化为HFD增强的BrCA中更有效的预防/治疗方法。将通过追求三个具体目标来测试该假设：1）阐明槲皮素对HFD增强的BrCA中的炎症的阶段特异性作用; 2）评估M-Phi-s是否是HFD增强的BrCA中槲皮素的抗炎作用的靶标;以及3）确定SIRT 1是否是槲皮素在HFD增强的BrCA中调节M-Phi诱导的炎症的作用的介体。在第一个目标下，将喂食HFD以诱导肥胖的BrCA的C3（1）SV 40 Tag小鼠模型将用于确定槲皮素对炎症和随后的肿瘤发生和总生存的阶段特异性作用。在第二个目标下，将使用体内M-Phi操作技术，例如将BrCA的C3（1）Tag转基因小鼠模型与MCP-1敲除小鼠杂交，以产生BrCA的M-Phi缺陷小鼠模型。这将有助于确定M-Phi-s对槲皮素在HFD增强的BrCA中的益处的作用。最后，在目标3下，将使用SIRT 1操作技术来检查SIRT 1作为槲皮素对HFD增强的BrCA中M-Phi诱导的炎症的影响的介体的作用。所提出的研究的创新在于将SIRT 1作为生物活性膳食组分槲皮素在HFD增强的BrCA中调节M-Phi诱导的炎症中的益处的介导剂。拟议的研究是重要的，因为它解决了预防HFD增强的BrCA的发病率和进展，通过使用膳食食物成分靶向炎症，这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.