Nutritional Regulation of Catalase and Colorectal Cancer

过氧化氢酶与结直肠癌的营养调节

• 批准号: 6524842
• 负责人: SUMIO YANO
• 金额: $ 7.8万
• 依托单位: PONCE SCHOOL OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-09-30 至 2003-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6524842
• 关键词: HeLa cells; SDS polyacrylamide gel electrophoresis; binding sites; biological signal transduction; butyrates; carcinogenesis; catalase; colorectal neoplasms; enzyme activity; enzyme induction /repression; enzyme linked immunosorbent assay; enzyme mechanism; enzyme substrate complex; immunoaffinity chromatography; immunoprecipitation; intermolecular interaction; nutrition aspect of cancer; nutrition related neoplasm /cancer; nutrition related tag; oxidative stress; oxidoreductase; phosphorylation; protein tyrosine kinase; site directed mutagenesis; tissue /cell culture; transfection /expression vector; ultraviolet spectrometry; western blottings

DESCRIPTION (provided by applicant) Susceptibility to cancer is influenced by dietary components. Indeed, diets rich in fat, nitrogen iron cause a high incidence of colorectal cancer, involve oxidative stress that impairs tumor suppressor function. Fiber-rich diets such as grain, vegetable and fruits, on the other hand, produce butyrate in the gut to suppress the incidence. Previous studies have postulated several roles for butyrate in the suppression of tumorigenesis, but it is still unclear how butyrate is linked to the regulation of oxidants and antioxidants. The researchers' preliminary data suggest that, upon its tyrosine phosphorylation, catalase binds Grb2 and Pl3Kp85, regulatory proteins of insulin signaling, and that catalase contains a consensus sequence of "suppressor of cytokine signaling" that enables it to bind elongin c, an essential factor for elongation of RNA synthesis. Importantly, butyrate induces catalase and suppresses its tyrosine phosphorylation and binding. Therefore, it is hypothesized that butyrate induces catalase and regulates an interaction of catalase with Grb2, Pl3Kp85 and elongin c to suppress hydrogen peroxide (H2O2) and its related damage, that would otherwise initiate and stimulate colorectal cancer. Thus, understanding the butyrate-dependent catalase regulation should provide new strategies to control colorectal cancer. To prove this hypothesis, the following aims are proposed: (1) Aim 1 is to determine the mechanisms of catalase binding with Grb2, Pl3Kp85, and elongin c, and the control by butyrate; (2) Aim 2 is to characterize the catalase that butyrate induces in human colorectal cancer cell line. To achieve these goals, the researchers will determine: (a) the binding sites of catalase whose mutation affects the complex formation, (b) the effects of butyrate on protein tyrosine kinase that phosphorylates catalase, (c) the binding-dependent alteration of catalase activity and oxidant-dependent p53 activation, and (d) the identities of catalase that butyrate induces; i.e., peroxisomal or cytosolic catalase. This study postulates a novel and innovative concept that catalase activity is modulated by a cell signaling- and intermolecular association-dependent mechanism. This research will allow the investigators to establish how butyrate regulates the catalase-activity and its binding with signaling molecules, that contribute to control cell mitogenesis and oxidant-dependent tumorigenesis.

描述（由申请人提供） 癌症易感性受到饮食成分的影响。 确实，饮食 富含脂肪、氮铁导致大肠癌高发， 涉及损害肿瘤抑制功能的氧化应激。 富含纤维 另一方面，谷物、蔬菜和水果等饮食会产生丁酸盐 在肠道中抑制发病率。 先前的研究假设 丁酸盐在抑制肿瘤发生方面具有多种作用，但它是 目前尚不清楚丁酸与氧化剂的调节有何关系 抗氧化剂。 研究人员的初步数据表明，根据其 酪氨酸磷酸化，过氧化氢酶结合 Grb2 和 Pl3Kp85，调节蛋白 胰岛素信号传导，并且过氧化氢酶包含以下共有序列 “细胞因子信号传导抑制剂”，使其能够结合 elongin c，一种 RNA合成延长的重要因素。 重要的是，丁酸盐 诱导过氧化氢酶并抑制其酪氨酸磷酸化和结合。 因此，假设丁酸盐诱导过氧化氢酶并调节 过氧化氢酶与 Grb2、Pl3Kp85 和 elongin c 相互作用抑制氢 过氧化物（H2O2）及其相关损害，否则会引发和 刺激大肠癌。 因此，了解丁酸依赖性 过氧化氢酶调节应提供控制结直肠癌的新策略 癌症。 为了证明这一假设，提出以下目标： (1) 目标1 目的是确定过氧化氢酶与 Grb2、Pl3Kp85 和 延长素c，以及丁酸盐对照； (2) 目标 2 是表征 丁酸盐在人结直肠癌细胞系中诱导的过氧化氢酶。 到 为了实现这些目标，研究人员将确定：(a) 的结合位点 过氧化氢酶的突变影响复合物的形成，（b）的影响 磷酸化过氧化氢酶的蛋白酪氨酸激酶上的丁酸盐，(c) 过氧化氢酶活性的结合依赖性改变和氧化剂依赖性p53 激活，以及 (d) 丁酸盐诱导的过氧化氢酶的特性； IE。， 过氧化物酶体或胞质过氧化氢酶。 这项研究假设了一种新颖且 过氧化氢酶活性由细胞信号传导调节的创新概念- 和分子间缔合依赖机制。 这项研究将允许 研究人员确定丁酸盐如何调节过氧化氢酶活性 及其与信号分子的结合，有助于控制细胞 有丝分裂发生和氧化剂依赖性肿瘤发生。