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 鱼油及其omega-3脂肪酸衍生物DHA和EPA对CRT的影响是有争议的：一些研究表明， 促进和其他抑制。我们在初步研究中发现，鱼油促进，而EPA抑制 结肠炎相关CRT。这些差异是否适用于偶发CRT尚不清楚。这是临床上 重要的是，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氧化代谢生成消退素的关键酶 和它们的前体（例如，18-HEPE和RvE、17-HDHA和RvE）。15-LOX-1和resolvins抑制IM- 重要途径（例如，TNF-α，IL-1 β），其增强异常Wnt/β-连环蛋白（Wnt/β-连环蛋白）信号传导， 其是CRT的驱动器。15-LOX-1的表达通常在人CRT早期丢失。15-LOX-1是否 表达缺失减少了DHA和EPA的消退素产生，并降低了DHA和EPA对 CRT未知。我们的初步数据显示，在大肠杆菌中，15-LOX-1-Gut表达是一种靶向的15-LOX-1表达。 小鼠）增强消退素的产生，抑制APC突变驱动的B-连环蛋白激活和CRT，减弱 艾德对DHA诱导的CRT促进作用增强，对EPA诱导的CRT抑制作用增强。我们假设15-LOX- 1在结肠上皮细胞中的表达对于DHA和EPA产生消退素和调节Wnt/B-1是至关重要的。 连环蛋白信号传导和CRT。目的1和2将决定15-LOX-1增加（目的1）和功能丧失的影响。 在结肠上皮细胞中对来自DHA和EPA、CRT和B-连环蛋白信号传导的消退素产生的作用（目的2）。 对于目标1，我们将使用15-LOX-1-Gut小鼠。目的二是培育肠道12-S-LOX转基因小鼠 用12/15-LOX敲除小鼠表达12-S-LOX以将12-S-LOX重建靶向肠上皮细胞。无论是 为了达到目的，小鼠将被喂食对照、DHA或EPA饮食并用AOM处理以诱导CRT。团体将在- 对消退素及其前体、CRT、细胞增殖和凋亡、TNF-α、IL-1 β和活化的B- 连环蛋白水平和Wnt/B-连环蛋白靶基因（c-Myc、Cyclin D1、Axin2）mRNA水平。我们还将评估 15-LOX-1在人结肠癌中的功能获得（aim 1）和下调（aim 2）的作用， 从患者的结肠隐窝中分离并与各种浓度的EPA培养的正常类器官， DHA对消退素生成、细胞增殖、细胞分化和Wnt/B-连环蛋白信号传导的影响。目标3将- 确定结肠上皮细胞和白细胞中15-LOX-1表达对消退的时间效应 一代和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的起始或进展阶段（子目的3A）或在 AOM诱导的CRT（子目标3B）。小鼠将被喂食DHA或EPA饮食，并比较针对以下描述的终点： 目标1和2。我们的研究结果将指导努力开发干预措施，以防止CRT的基础上了解 宿主因素（例如，15-LOX-1）影响DHA和EPA对CRT的调节。

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.