DIET,APOPTOSIS AND COLON CARCINOGENESIS

描述：其他人和我们已经证明鱼油和玉米油是有保护作用的 对抗实验诱导的结肠癌。最近我们报道了这一点， 保护作用是由于FISH具有更高的稳定的细胞凋亡水平 补充石油。此外，我们还展示了一种协同保护作用 鱼油和果胶(一种高度可发酵的纤维)在两种情况下的结合 肿瘤发生率和自发性细胞凋亡的增强。我们现在展示的数据是 鱼油和果胶的结合也增强了体内的靶向细胞凋亡。 在给予致癌物偶氮甲烷(AOM)后的前12小时。 这项提议的总体目标是在机械论层面上理解如何 富含n-3脂肪酸的鱼油可诱导结肠细胞凋亡，从而 防止实验诱导的结肠癌发生。次要目标 是为了确定如何在含鱼油的饲料中添加果胶 与纤维素相比，协同增强对鱼的保护作用 油。假设：观察到鱼油促进细胞凋亡 补充是由于(1)COX-2表达下调，提供了 丁酸盐诱导细胞凋亡的允许环境；和/或(2)改变 线粒体功能，这是允许丁酸诱导的细胞凋亡。 为了验证这些假说，我们有三个具体的目标：1.在体内确定 COX-2表达、细胞凋亡、p21waf1/Cipi p27kip1、Cyclin DL、细胞 增殖和分化与膳食脂肪、丁酸和 在推广阶段给予致癌物。使用3 x 2 x 2 析因设计(鱼油、鱼油乙酯或玉米油补充剂； 加或减丁酸盐；生理盐水或AOM)，我们将使用定量 大鼠结肠连续切片的免疫组织化学研究 环氧合酶-2、细胞凋亡、p21Wafi/Cipi和Cyclin D1、p27Kip1的表达 分化，以及在同一细胞中的凋亡。2.体内测定 与特定目标1相同的标志物的表达，作为饮食的函数 脂肪、丁酸盐和AOM，但在结肠癌初期。3. 在体外系统中确定鱼油是否因此改变线粒体功能 为丁酸诱导的细胞凋亡创造一个宽松的环境。使用3 x 2 析因设计(鱼油；鱼油乙酯或玉米油；生理盐水或AOM)， 在推广阶段，我们将确定对已知指标的影响 线粒体功能、活性氧、心磷脂脂肪酸 组成和丁酸诱导的细胞凋亡。对饮食的理解 影响结肠肿瘤发病率的设计有重要的后果 临床试验和未来的饮食建议。

DESCRIPTION: Others and we have shown that fish oil vs corn oil, is protective against experimentally-induced colon cancer. Recently we reported that this protective effect is due to a higher steady state level of apoptosis with fish oil supplementation. In addition, we show a synergistic protective effect of the combination of fish oil and pectin (a highly fermentable fiber) on both tumor incidence and enhancement of spontaneous apoptosis. We now show data that the combination of fish oil and pectin also enhances targeted apoptosis within the first 12 hours after administration of the carcinogen azoxymethane (AOM). The overall goal of this proposal is to understand, at a mechanistic level, how fish oil, high in n-3 fatty acids, induces apoptosis in colonocytes and thus protects against experimentally-induced colon tumorigenesis. A secondary goal is to determine how supplementing fish oil-containing diets with pectin compared to cellulose synergistically enhances the protective effect of fish oil. Hypotheses: The observed enhancement of apoptosis with fish oil supplementation is due to (1) down regulation of Cox-2 expression providing a permissive environment for butyrate-induced apoptosis; and/or (2) alterations in mitochondrial function which are permissive for butyrate-induced apoptosis. To test these hypotheses we have three specific aims: 1. Determine in vivo expression of Cox-2, apoptosis, p21waf1/CipI p27kip1, Cyclin Dl, cell proliferation and differentiation as a function of dietary lipid, butyrate, and carcinogen administration, during the stage of promotion. Using a 3 x 2 x 2 factorial design (fish oil, fish oil ethyl esters, or corn oil supplementation; plus or minus butyrate; saline or AOM), we will use quantitative immunohistochemistry on serial sections of rat colon to detect patterns of expression of Cox-2, apoptosis, p21 WAFI/CIPI and Cyclin Dl; and p27Kip1 differentiation, and apoptosis in the same cells. 2. Determine in vivo expression of the same markers as in specific aim #1, as a function of dietary lipid, butyrate, and AOM, but during the initiation stage of colon cancer. 3. Determine in an ex vivo system if fish oil alters mitochondrial function thus creating a permissive environment for butyrate-induced apoptosis. Using a 3 x 2 factorial design (fish oil; fish oil ethyl esters or corn oil; saline or AOM), during the stage of promotion we will determine the effect on known indicators of mitochondrial function, reactive oxygen species, cardiolipin fatty acid composition and butyrate-induced apoptosis. An understanding of how diet affects colon tumor incidence has important consequences for the design of clinical trials and for future dietary recommendations.