Anti-promoting effects of Triterpenes alone or combined with other phytochemicals

描述(申请人提供)：这项建议侧重于识别天然化合物和天然化合物的组合，这些化合物的作用类似于卡路里限制(CR)模拟。熊果酸(UA)，一种存在于迷迭香、苹果、浆果、紫苏和其他来源中的五环三萜类化合物，以及其他几种相关的三萜类化合物，在其他研究中已被证明可以抑制TPA促进皮肤肿瘤的发生，并阻断Akt信号和NFkB信号。有证据表明，尿酸也可能调节糖皮质激素受体(GR)的活性。在初步研究中，包括在这一应用中增加的新数据，我们发现UA对TPA诱导的表皮Akt、NFkB、p38MAPK和JNK的激活具有抑制作用。UA还能抑制TPA诱导的表皮过度增殖。值得注意的是，当UA与白藜芦醇(RES)联合给予时，似乎产生了对这些信号通路的协同抑制，以及TPA诱导的表皮过度增殖。此外，联合使用UA和Res可显著诱导TPA治疗后表皮AMPK的激活。初步实验表明，尿酸对人角质形成细胞系中的GR有调节作用。更多的新数据表明，RAPA、UA、Res和UA+Res的组合抑制了毛囊隆起区域可能的干细胞的增殖。我们在合成/制备另外的五环三萜类化合物方面取得了重大进展。我们建议使用描述良好的两阶段皮肤癌发生模型来探索UA和一系列相关的五环三萜类化合物的化学预防作用的机制。此外，我们将探索当UA(或在P.Frutescens中发现的更有效的三萜)与其他植物化学物质如RES、姜黄素(Curc)、6-shogaol(6Sho)或RAPA相结合时，将产生相加或可能协同的化学预防作用的可能性。我们将测试这一假设，即UA单独或与其他植物化学物质联合作用，通过调节生长因子信号、炎症信号和可能的其他信号途径来抑制启动的角质形成细胞的增殖。三萜类化合物(如尿酸)与其他化学预防化学品/植物化学物质的组合将产生相加或协同的CR模拟活性的假设也将得到检验。具体目的是：i)检测UA及一系列相关五环三萜对TPA诱导的表皮信号通路的影响；ii)检测UA及一系列相关五环三萜在促癌过程中调节表皮GR功能的能力；iii)检测UA及一系列相关三萜对角质形成细胞(包括隆起区KSCS)和皮肤炎症的影响，以及它们抑制TPA促皮肤肿瘤的能力；iv)检测UA与其他抗炎化学物质联合是否能对TPA促皮肤肿瘤起到协同抑制作用。

DESCRIPTION (provided by applicant): This proposal focuses on identifying natural compounds and combinations of natural compounds that behave as calorie restriction (CR) mimetics. Ursolic acid (UA), a pentacyclic triterpene compound found in rosemary, apples, berries, Perilla frutescens (P. frutescens) and other sources, as well as several other related triterpenoids have been shown to inhibit skin tumor promotion by TPA and to block both Akt signaling as well as NFkB signaling in other studies. Evidence exists that UA may also modulate activity of the glucocorticoid receptor (GR). In preliminary studies, including new data added to this application, we have found that UA had inhibitory effects on epidermal Akt, NFkB, p38 MAPK and JNK activation induced by TPA treatment. UA also inhibited TPA-induced epidermal hyperproliferation. Notably, UA, when given in combination with resveratrol (Res), appeared to produce synergistic inhibition of these signaling pathways, as well as TPA-induced epidermal hyperproliferation. Furthermore, combinations of UA and Res dramatically induced activation of epidermal AMPK following treatment with TPA. Preliminary experiments suggest that UA modulates the GR in a human keratinocyte cell line. Additional new data demonstrates that Rapa, UA, Res and the combination of UA+RES suppress the proliferation of putative stem cells from the bulge region of hair follicles. We have made significant progress in the synthesis/preparation of additional pentacyclic triterpenes found in P. frutescens. We propose to use the well-characterized two-stage skin carcinogenesis model to explore the mechanisms that underlie the chemopreventive properties of UA and a series of related pentacyclic triterpenes. In addition, we will explore the possibility that UA (or a more potent triterpene found in P. frutescens) when combined with other phytochemicals such as Res, curcumin (Curc), 6-shogaol (6Sho) or Rapa will produce either additive or possibly synergistic chemopreventive effects. We will test the hypothesis that UA alone or in combination with other phytochemicals acts as a CR mimetic by modulating growth factor signaling, inflammatory signaling and possibly other signaling pathways to suppress proliferation of initiated keratinocytes. The hypothesis that combinations of triterpenoid compounds (such as UA) together with other chemo- preventive chemicals/phytochemicals will produce additive or synergistic CR mimetic activity will also be tested. The specific aims are: i) Examine the effect of UA and a series of related pentacyclic triterpenes on epidermal signaling pathways induced by TPA; ii) Examine the ability of UA and a series of related pentacyclic triterpenes to modulate epidermal GR function during tumor promotion; iii) Examine the effect of UA and a series of related triterpenes on keratinocyte proliferation (including bulge region KSCs) and skin inflammation in relation to their ability to inhibit skin tumor promotion by TPA; iv) Examine whether UA combined with other anti-inflammatory chemicals can achieve synergistic inhibitory effects toward skin tumor promotion by TPA.