Establishing the molecular and cellular mechanisms of Lgr5 signaling for controlling cancer stem cell behavior

建立 Lgr5 信号传导控制癌症干细胞行为的分子和细胞机制

• 批准号: 9764146
• 负责人: Joshua Clair Snyder
• 金额: $ 18.94万
• 依托单位: DUKE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-09-01 至 2021-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9764146
• 关键词: Adopted; Alternative Therapies; Attenuated; Automobile Driving; Basic Science; Biochemical; Biochemistry; Biological Assay; Cancer Biology; Cancer Burden; Cancer Control; Cancer Etiology; Cell Differentiation process; Cell Proliferation; Cell membrane; Cells; Cellular biology; Cessation of life; Clinical; Colon; Colon Carcinoma; Critical Pathways; Data; Development Plans; Differentiation Therapy; Disease Outcome; Epithelium; Event; Filopodia; Formulation; Foundations; Funding; Future; G-Protein-Coupled Receptors; Genetic Engineering; Goals; Homeostasis; Homologous Gene; In Vitro; Intervention; Intestinal Cancer; Intestines; Knowledge; LGR5 gene; Leucine; Life Expectancy; Link; Literature; Malignant Neoplasms; Mediating; Membrane Proteins; Mission; Molecular; Molecular Biology; Molecular Chaperones; Molecular Target; Mus; Mutation; Neoplasm Metastasis; Normal Cell; Normal tissue morphology; Outcome; Pathway interactions; Pharmacology; Population; Positioning Attribute; Property; Publications; Publishing; Refractory; Regulation; Research; Research Proposals; Rhodopsin; Role; Route; Science; Signal Pathway; Signal Transduction; Small Intestines; Stem cells; Survival Rate; Technology; Testing; Therapeutic; Training; Translating; Tumor Initiators; Tumor Stem Cells; Undifferentiated; United States; Woman; Work; adult stem cell; anticancer research; base; cancer diagnosis; cancer stem cell; carcinogenesis; career; career development; cell behavior; chemotherapy; drug candidate; high throughput screening; improved; in vivo; inhibitor/antagonist; innovation; member; men; novel; novel therapeutics; outcome forecast; programs; protein transport; receptor; research and development; screening; self-renewal; skills; small molecule; small molecule inhibitor; stem; stem cell biology; stem cell differentiation; stem cell fate; targeted treatment; therapy resistant; trafficking; trans-Golgi Network; tumor growth; ubiquitin ligase

ABSTRACT Colon cancer is the second leading cause of cancer deaths among men and women combined. Therefore, alternative therapies are of critical need. In normal tissue, intestinal stem cells act to enable renewal of the entire epithelium every week. It is now known that the transformation of stem cells into colon cancer stem cells is a major inciting event that underlies carcinogenesis. Cancer stem cells are tumor-initiating cells, are refractory to therapy, and are linked to the very poor prognosis associated with late-stage colon cancer diagnosis. Better therapies may result if colon cancer stem cells could be eliminated. However, eradicating this population of cells is an extremely challenging problem, due to the intrinsic capacity of colon cancer stem cells to be long-lived, self-renewing, and highly proliferative. One proposed solution to this problem is to pharmacologically bias cancer stem cell fate toward a terminally differentiated cell fate. In other words, drive cancer stem cells to adopt a cell fate that does not proliferate, that has a short life expectancy, and that is sensitive to chemotherapy. Realization of this differentiation therapy requires that the identity of the cancer stem cell be known and that a candidate molecular target exists for a therapeutic entry point. To this end, the leucine-rich G protein coupled receptor-5 (Lgr5) has been found to act as a marker for colon cancer stem cells and is a tantalizing pharmacological target. Lgr5, together with its homologue Lgr4, act as modulators for the Wnt/ßcatenin signaling pathway. Wnt/ßcatenin signaling is a critical pathway that regulates stem cell homeostasis in the intestine. Mutations in this pathway result in excessive signaling and strongly bias stem cell behavior toward that of a long-lived and highly proliferative cancer stem cell. Lgr5 is therefore an attractive pharmacological target for counteracting this imbalance and restoring normal cell fate dynamics. However, the mechanisms of Lgr5-signaling and its roles in vivo are still vague and represent a major knowledge gap. Therefore, the objective of this proposal will be to determine how Lgr5-signaling controls stem and cancer stem cell fate. To accomplish this objective, I will test the central hypothesis that inhibition of Lgr5 internalization attenuates Wnt/ßcatenin signaling and promotes cancer stem cell differentiation. Three specific aims have been proposed to test this hypothesis and will in (Aim 1) Clarify the mechanism of Lgr5-mediated Wnt/ßcatenin signaling, (Aim 2) Elucidate Lgr5-dependent signaling mechanisms coordinating stem cell behavior, and (Aim 3) Identify small molecule interventions for driving cancer stem cell differentiation. Key preliminary findings are described in this research plan that enable formulation of the central hypothesis and specific aims. The integration of biochemistry, cell biology, pharmacology, and cancer biology make this an innovative research proposal. This proposal is significant because it will transform Lgr5 from a stem cell marker into a high-value drug candidate that can be pharmacologically targeted to control cancer stem cell fate. My research and career development plan demonstrates the interdisciplinary training that I have received. This spans the biomedical science spectrum and includes stem cell biology, molecular biology, genetic engineering, cancer research, biochemistry, cell-fate analysis, and high-throughput screening. This NCI K22 proposal will solidify the integration of these skills and facilitate my own independent research program, which is my short-term career objective. By completing this proposal I will be in a position to obtain R01 funding and work towards my long-term career objective of making high-impact and foundational discoveries that can be translated into treatments and cures for cancer. In so doing, I will become an instrumental component of the NCI's mission “to accelerate the rate of scientific discovery and reduce the burden of cancer in the United States and around the world.”

摘要 结肠癌是男性和女性癌症死亡的第二大原因。因此， 替代疗法是迫切需要的。在正常组织中，肠道干细胞的作用是使 每周一次完整的上皮组织。现已知干细胞转化为结肠癌干细胞 是一个重大的煽动事件，是癌症发生的基础。癌症干细胞是启动肿瘤的细胞，是 治疗难治，与晚期结肠癌预后极差有关。 诊断。如果结肠癌干细胞能够被消除，可能会产生更好的治疗方法。然而，根除这一点 由于结肠癌干细胞的内在能力，细胞的数量是一个极具挑战性的问题。 具有长寿、自我更新和高度增殖的能力。对这个问题的一个建议的解决方案是 从药理上讲，癌症干细胞的命运倾向于终末分化的细胞命运。换句话说，开车 癌症干细胞采用一种不会增殖、预期寿命短的细胞命运，那就是 对化疗敏感。这种辨证治疗的实现要求癌症的同一性 干细胞是已知的，并且存在治疗切入点的候选分子靶点。为此， 富含亮氨酸的G蛋白偶联受体-5(Lgr5)被认为是结肠癌干细胞的标志 是一个诱人的药理靶点。LGR5和它的同系物LGR4一起作为调节器 WNT/？连环蛋白信号通路。WNT/？连环蛋白信号通路是调节干细胞的关键途径 肠道内的动态平衡。这一途径的突变导致过度信号传递和强烈偏向干细胞 长寿和高度增殖的癌症干细胞的行为。因此，LG5是一个有吸引力的 对抗这种失衡和恢复正常细胞命运动力学的药理靶点。然而， Lgr5信号转导机制及其在体内的作用仍然不清楚，是一个重大的知识空白。 因此，这项提案的目标将是确定Lgr5信号如何控制干细胞和癌症 干细胞的命运。为了实现这一目标，我将测试Lgr5抑制的中心假设 内化减弱Wnt/？连环蛋白信号转导，促进肿瘤干细胞分化。三个具体的 已经提出了AIMS来检验这一假说，并将在(AIMS 1)中阐明Lgr5介导的机制 WNT/？连环蛋白信号转导，(目标2)阐明Lgr5依赖的信号机制协调茎 细胞行为，以及(目标3)确定用于驱动癌症干细胞的小分子干预 差异化。这项研究计划中描述了主要的初步发现，使制定 中心假设和具体目标。生物化学、细胞生物学、药理学和癌症的结合 生物学使这成为一个创新的研究方案。这项提议意义重大，因为它将使Lgr5 从干细胞标记物转变为高价值的候选药物，可以通过药理学靶向控制 癌症干细胞的命运。我的研究和职业发展计划体现了跨学科的培训 这是我收到的。它跨越了生物医学科学的范围，包括干细胞生物学、分子生物学 生物学、基因工程、癌症研究、生物化学、细胞命运分析和高通量筛选。 这份NCI K22计划将巩固这些技能的整合，并促进我自己的独立研究 计划，这是我的短期职业目标。通过完成这份提案，我将能够获得 R01资金，并朝着我的长期职业目标努力，使其具有高影响力和基础性 可以转化为癌症治疗和治愈的发现。这样做，我将成为一名 NCI使命的重要组成部分“加快科学发现的速度，减少 癌症在美国和世界各地造成的负担。