DIET,APOPTOSIS AND COLON CARCINOGENESIS

饮食、细胞凋亡和结肠癌发生

• 批准号: 6497572
• 负责人: JOANNE R LUPTON
• 金额: $ 32.74万
• 依托单位: TEXAS A&M UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-02-01 至 2005-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6497572
• 关键词: apoptosis; butyrates; cardiolipins; cell differentiation; cell proliferation; chemical carcinogen; chemical carcinogenesis; colon neoplasms; cyclin dependent kinase; cyclins; dietary lipid; dietary supplements; enzyme activity; enzyme inhibitors; free radical oxygen; immunocytochemistry; laboratory rat; marine animal oil; mitochondria; nutrition aspect of cancer; nutrition related tag; prostaglandin endoperoxide synthase; vegetable oils

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.

描述：其他人和我们已经证明鱼油与玉米油相比，具有保护作用 对抗实验诱发的结肠癌。最近我们报道了这 保护作用是由于鱼细胞凋亡的稳态水平较高 油的补充。此外，我们还表现出协同保护作用 两者均含有鱼油和果胶（一种高度发酵纤维） 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 鱼油和果胶的组合还可以增强细胞内的靶向细胞凋亡 施用致癌物质氧化偶氮甲烷 (AOM) 后的前 12 小时。 该提案的总体目标是在机械层面上理解如何 鱼油富含 n-3 脂肪酸，可诱导结肠细胞凋亡，从而 防止实验诱导的结肠肿瘤发生。次要目标 是确定如何在含鱼油的饮食中补充果胶 与纤维素相比，协同增强对鱼类的保护作用 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宽松环境；和/或 (2) 变更 线粒体功能，允许丁酸盐诱导细胞凋亡。 为了检验这些假设，我们有三个具体目标： 1. 确定体内 Cox-2的表达，细胞凋亡，p21waf1/CipI p27kip1，Cyclin Dl，细胞 增殖和分化与饮食脂质、丁酸和 致癌物管理，推广阶段。使用 3 x 2 x 2 因子设计（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 对大鼠结肠连续切片进行免疫组织化学检测 Cox-2、细胞凋亡、p21 WAFI/CIPI 和 Cyclin D1 的表达；和 p27Kip1 同一细胞中的分化和凋亡。 2. 体内测定 作为饮食的函数，表达与具体目标#1相同的标记 脂质、丁酸盐和 AOM，但在结肠癌的起始阶段。 3. 在离体系统中确定鱼油是否改变线粒体功能 为丁酸盐诱导的细胞凋亡创造宽松的环境。使用 3 x 2 因子设计（鱼油；鱼油乙酯或玉米油；盐水或 AOM）， 在推广阶段我们会判断对已知指标的影响 线粒体功能、活性氧、心磷脂脂肪酸 成分和丁酸盐诱导的细胞凋亡。了解如何饮食 影响结肠肿瘤的发生率对设计具有重要影响 临床试验和未来的饮食建议。