15-LOX-1 regulation of resolving generation to modulate colon cancer

我们的长期目标是开发新的干预措施来预防结直肠肿瘤发生(CRT)。的影响 一些研究表明，CRT上的鱼油及其omega-3脂肪酸衍生物DHA和EPA存在争议 提拔和其他压制。我们在初步研究中发现，鱼油促进作用，而环保局则抑制作用 结肠炎相关性CRT。这些差异是否适用于散发性CRT尚不清楚。这是临床上的 重要的是因为DHA和EPA被广泛用作膳食补充剂和FDA批准的治疗方法。15- 脂氧合酶-1(15-LOX-1)是DHA和EPA氧化代谢生成溶血素的关键酶 及其前体(如18-HEPE和RVE、17-HDHA和RVE)。15-LOX-1和溶血素抑制免疫反应 重要途径(如肿瘤坏死因子-α、白介素1-β)增强异常的WNT/β-连环蛋白(WNT/B-连环蛋白)信号， 它是CRT的驱动因素。15-LOX-1在人CRT中的表达通常在早期丢失。15-LOX-1是否 表达缺失减少DHA和EPA产生的解析素，并降低DHA和EPA对 CRT未知。我们的初步数据显示，肠道靶向15-LOX-1表达(15-LOX-1-Gut 小鼠)增加解析素的产生，抑制APC突变驱动的B-连环蛋白激活和CRT，减弱- ED DHA促进CRT表达，增强EPA诱导的CRT抑制作用。我们假设15-LOX- 1在结肠上皮细胞的表达对DHA和EPA产生解析素和调节Wnt/B-起关键作用。 连环蛋白信号和CRT。目标1和目标2将确定15-LOX-1增益(目标1)和功能损失的效果。 TION(目标2)在结肠上皮细胞从DHA和EPA、CRT和B-连环蛋白信号中产生解析素。 对于目标1，我们将使用15-LOX-1肠道小鼠。对于目标2，我们将培育肠道12-S-LOX转基因小鼠 以12/15-LOX基因敲除小鼠为靶向12-S-LOX重组到肠上皮细胞的表达。在这两个地方 目的：给小鼠饲喂对照组、DHA或EPA饲料，并用AOM处理以诱导CRT。群组将被- 比较溶血素及其前体、CRT、细胞增殖和凋亡、肿瘤坏死因子-α、白介素1-β和活化的B- 连环蛋白水平及Wnt/B-连环蛋白靶基因(c-Myc、Cyclin D1、Axin2)的mRNA水平。我们还将评估 15-LOX-1对人结肠癌和结肠癌细胞功能增强和下调的影响 从患者的结肠隐窝中分离出正常的有机物质，并与不同浓度的EPA和 DHA在分解素生成、细胞增殖、细胞分化和Wnt/B-catenin信号转导中的作用。AIM 3将去- 15-LOX-1在结肠上皮细胞和白细胞中表达的时间效应 产生和CRT。15-LOX-1转基因表达将靶向肠上皮细胞并诱导 在AOM诱导的CRT的启动或进展阶段(SubAim 3A)或在AOM诱导的CRT之前靶向于白细胞 AOM诱导的CRT(SubAim 3B)。小鼠将被喂以DHA或EPA饲料，并比较下列终点 目标1和目标2。我们的发现将指导基于理解开发预防CRT的干预措施 影响CRT的DHA和EPA调制的宿主因素(例如15-LOX-1)。

Our long-term goal is to develop novel interventions to prevent colorectal tumorigenesis (CRT). The effects of fish oil and its omega-3 fatty acid derivatives DHA and EPA on CRT are controversial: some studies show promotion and others suppression. We found in preliminary studies that fish oil promoted while EPA inhibited colitis-associated CRT. Whether these differences are applicable to sporadic CRT is unknown. This is clinically important because DHA and EPA are widely used as dietary supplements and FDA-approved treatments. 15- lipoxygenase-1 (15-LOX-1) is a critical enzyme for DHA and EPA oxidative metabolism to generate resolvins and their precursors (e.g., 18-HEPE and RvEs, 17-HDHA and RvEs). 15-LOX-1 and resolvins suppress im- portant pathways (e.g., TNF-α, IL-1β) that potentiate aberrant Wnt/beta-catenin (Wnt/B-catenin) signaling, which is a driver of CRT. 15-LOX-1 expression is commonly lost early during human CRT. Whether 15-LOX-1 expression loss reduces resolvin production from DHA and EPA and reduces the effects of DHA and EPA on CRT is unknown. Our preliminary data show that intestinally targeted 15-LOX-1 expression (15-LOX-1-Gut mice) enhanced resolvin production, suppressed APC mutation-driven B-catenin activation and CRT, attenuat- ed DHA-induced CRT promotion, and enhanced EPA-induced CRT suppression. We hypothesize that 15-LOX- 1 expression in colonic epithelial cells is critical for DHA and EPA to generate resolvins and modulate Wnt/B- catenin signaling and CRT. Aims 1 and 2 will determine the effects of 15-LOX-1 gain (aim 1) and loss of func- tion (aim 2) in colonic epithelial cells on resolvin generation from DHA and EPA, CRT, and B-catenin signaling. For aim 1, we will use 15-LOX-1-Gut mice. For aim 2, we will breed mice with intestinal 12-S-LOX transgenic expression with 12/15-LOX knockout mice to target 12-S-LOX reconstitution to intestinal epithelial cells. In both aims, mice will be fed control, DHA, or EPA diet and treated with AOM to induce CRT. Groups will be com- pared for resolvins and their precursors, CRT, cell proliferation and apoptosis, TNF-α, IL-1β, and activated B- catenin levels, and Wnt/B-catenin target gene (c-Myc, Cyclin D1, Axin2) mRNA levels. We will also evaluate the effect of 15-LOX-1 gain of function (aim 1) and downregulation (aim 2) in human colonic cancerous and normal organoids isolated from patients' colonic crypts and cultured with various concentrations of EPA and DHA on resolvin generation, cell proliferation, cell differentiation, and Wnt/B-catenin signaling. Aim 3 will de- termine the temporal effects of 15-LOX-1 expression in colonic epithelial cells and in leukocytes on resolvin generation and CRT. 15-LOX-1 transgenic expression will be targeted to intestinal epithelial cells and induced at either initiation or progression phases of AOM-induced CRT (subaim 3A) or targeted to leukocytes prior to AOM-induced CRT (subaim 3B). Mice will be fed DHA or EPA diets and compared for end points described for aims 1 and 2. Our findings will direct efforts to develop interventions to prevent CRT based on understanding of the host factors (e.g., 15-LOX-1) that affect DHA and EPA modulation of CRT.