ALOX15 regulation of colon cancer invasiveness via PI3P-linoleic acid metabolism

ALOX15 通过 PI3P-亚油酸代谢调节结肠癌侵袭性

• 批准号: 10545078
• 负责人: Imad Shureiqi
• 金额: $ 63.89万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-01-01 至 2026-12-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10545078
• 关键词: ALOX15 gene; APC mutation; Acids; Adenocarcinoma; Adverse event; Affect; American diet; Animals; Arachidonate 15-Lipoxygenase; Automobile Driving; Azoxymethane; Benign; Biological Assay; Biological Markers; Breeding; CD44 gene; CDX2 gene; Cancer Etiology; Cell membrane; Cellular Membrane; Cessation of life; Chemicals; Chemopreventive Agent; Colon; Colon Carcinoma; Colonic Polyps; Colorectal; Colorectal Cancer; Complex; Consumption; Corn Oil; Cyclin D1; DNA Sequence Alteration; Data; Development; Diet; Disease; Doxycycline; Endosomes; Enzymes; Event; Genes; Goals; Human; Immunodeficient Mouse; In Vitro; Incidence; Induced Mutation; Intake; Integration Host Factors; Intervention; Invaded; KRAS2 gene; KRASG12D; Knowledge; LDL-Receptor Related Protein 1; LGR5 gene; Lentivirus; Linoleic Acids; Lipoxygenase 1; Liquid Chromatography; LoxP-flanked allele; Mass Spectrum Analysis; Metabolism; Mucous Membrane; Mus; Mutation; Omega-6 Fatty Acids; Organoids; Phospholipids; Polyunsaturated Fatty Acids; Prevention strategy; Recycling; Regulation; Reporting; Research; Resected; Resolution; Risk; Rodent; Role; Sampling; Signal Transduction; System; Testing; Tissues; Transfection; Transgenic Organisms; United States; adenoma; aldehyde dehydrogenase 1; beta catenin; c-myc Genes; cancer invasiveness; carcinogenesis; colon cancer risk; colon carcinogenesis; dietary; dietary excess; drinking water; gain of function; in vivo; insight; lipoprotein receptor related protein 5; loss of function; mouse model; novel; novel chemoprevention; organoid transplantation; permissiveness; peroxidation; phosphatidylinositol 3-phosphate; prevent; preventive intervention; receptor; stem cell self renewal; stem cells; stemness; therapy development; tumor; tumorigenesis; villin

Colorectal cancer is the third leading cause of cancer deaths in the United States. The long-term goal of our research is to develop novel interventions to prevent colorectal carcinogenesis (CRC). CRC invasiveness, a critical adverse step during CRC progression, requires a combination of certain genetic mutations (e.g. APC, KRAS and Trp53 mutations), which are the key events to drive CRC. However, CRC progression also requires additional factors which increase aberrant Beta-catenin (B-catenin) activation above levels induced by APC/B- catenin mutations. Linoleic acid (LA), the most commonly consumed omega-6 polyunsaturated fatty acids in humans, increases both chemically (AOM)– and APC mutation– induced CRC tumorigenesis in mice. Nonetheless, human studies have been inconclusive regarding the impact of dietary LA on CRC. Determination of LA's role in CRC is important because American diets are enriched with LA while expression of the main metabolizing enzyme for LA,15-lipoxygenase-1 (ALOX15), is lost in human CRC. Recently, we found that 1) high dietary levels of LA promoted CRC by increasing phosphatidylinositol 3-phosphate (PI3P) containing LA (PI3P_LA), which increases LRP5 membranous recycling and subsequently B-catenin activation; 2) ALOX15- induced conversion of PI3P_LA to PI3P_13-HODE suppresses; LRP5 membranous recycling, B-catenin activation, CRC stemness and LA promotion of CRC, especially formation of large tumors, associated with CRC invasiveness; 3) ALOX15 loss of function (LOF) promotes large CRC tumor formation by azoxymethane in 12/15LOX-KO-12LOX (ALOX15-LOF) mice. Whether loss of ALOX15 expression promotes CRC invasiveness remains unknown. Our preliminary data show that ALOX15-LOF mice increased CRC invasiveness and targeted APC mutation into Lgr5+ colorectal stem cells induced CRC in the mice, which was blocked by transgenic ALOX15 expression. We therefore hypothesize that ALOX15 loss of function promotes CRC invasiveness by increasing PI3P_LA levels, which enhances LRP5 membranous recycling, thus potentiating Wnt/B-catenin signaling and subsequently stemness. Aim 1 will determine the effects of ALOX15 gain of function and ALOX15 LOF on LRP5, B-catenin activation, CRC stemness and invasiveness using CRC mouse models in which CRC invasiveness is promoted by either a combination of APC, KRASG12D and Trp53R172H mutations or Trp53R172H mutation with AOM induced B-catenin and KRAS mutations. Aim 2 will determine the effects of ALOX15 LOF on PI3P-LA, LRP5, B-catenin activation, stemness and invasiveness in human CRCs and examine the effects of ALOX15 re-expression via lentivirus Tet-on inducible system in human CRC-derived organoids on invasiveness in-vitro and in-vivo studies. The proposed studies are expected to provide important mechanistic insights into whether colonic ALOX15 expression as a host factor affects CRC invasiveness risk especially with high dietary LA intake. This gained knowledge could inform subjects with colorectal ALOX15 LOF to avoid high LA intake and spur development of interventions to target ALOX15 for re-expression to prevent invasive CRC.

在美国，结直肠癌是癌症死亡的第三大原因。我们的长期目标是 研究的目的是开发新的干预措施来预防结直肠癌的发生。CRC入侵，a 在CRC进展过程中的关键不利步骤，需要某些基因突变的组合(例如APC， KRAS和Trp53突变)，这是导致CRC的关键事件。然而，CRC进步也需要 在APC/B诱导的水平上增加异常的β-连环蛋白(B-连环蛋白)激活的其他因素- 连环蛋白突变。亚油酸(LA)，最常消费的omega-6多不饱和脂肪酸 人类，增加化学(AOM)和APC突变诱导的小鼠结直肠癌的发生。 尽管如此，关于饮食中LA对结直肠癌的影响，人类研究一直没有定论。测定法 LA在结直肠癌中的作用很重要，因为美国人的饮食中富含LA，而主要的 人类结直肠癌中LA代谢酶15-脂氧合酶-1(ALOX15)缺失。最近，我们发现1) 高水平的LA通过增加含有LA的磷脂酰肌醇3-磷酸(PI3P)促进结直肠癌 (PI3P_LA)，促进LRP5膜循环，进而激活B-连环蛋白；2)ALOX15- PI3P_LA向PI3P_13-HODE的诱导转化抑制；LRP5膜循环，B-连环蛋白 结直肠癌的激活、结直肠癌干细胞和LA促进，特别是与结直肠癌相关的大肿瘤的形成 侵袭性；3)ALOX15功能丧失(LOF)促进偶氮甲烷在小鼠体内形成大的结直肠癌 12/15LOX-KO-12LOX(ALOX15-LOF)小鼠。ALOX15表达缺失是否促进结直肠癌侵袭性 仍然不为人知。我们的初步数据显示，ALOX15-LOF小鼠增加了结直肠癌的侵袭性和靶向性 APC基因突变Lgr5+结直肠干细胞诱导小鼠结直肠癌的发生 ALOX15表达式。因此，我们假设ALOX15功能丧失通过以下方式促进CRC侵袭性 增加PI3P_LA水平，促进LRP5膜循环，从而增强Wnt/B-连环蛋白 信号和随后的茎。目标1将确定ALOX15的功能增益和ALOX15的影响 LOF对LRP5、B-连环蛋白激活、结直肠癌干性和侵袭性的影响 APC、KrasG12D和Trp53R172H突变或Trp53R172H突变的组合可促进侵袭性 AOM突变可引起B-连环蛋白和KRAS突变。目标2将确定ALOX15 LOF的效果 PI3P-LA、LRP5、B-catenin在人喉癌中的激活、干性和侵袭性及其作用 慢病毒Tet-On诱导系统在人结直肠癌细胞系中的再表达 体外和体内侵袭性研究。拟议中的研究有望提供重要的机制 深入了解作为宿主因素的结肠ALOX15表达是否影响CRC侵袭性风险，尤其是在 膳食中LA摄入量高。这种获得的知识可以通知患有结直肠癌ALOX15 LOF的受试者避免高 LA摄取和刺激针对ALOX15重新表达的干预措施的发展，以防止侵袭性CRC。