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: 9224155
• 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 2020-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9224155
• 关键词: Adopted; Alpha Cell; 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; 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 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.”

抽象的 结肠癌是男性和女性癌症死亡的第二大原因。所以， 替代疗法是至关重要的。在正常组织中，肠道干细胞起作用可更新 现在知道干细胞向结肠癌干细胞的转化 是构成致癌作用的主要煽动性事件。癌症干细胞是肿瘤发射细胞，是 对治疗的难治性，与晚期结肠癌相关的预后非常差。 诊断。如果可以消除结肠癌干细胞，则可能会产生更好的疗法。但是，消除了这个 由于结肠癌干细胞的内在能力，细胞的种群是一个极其挑战的问题 长寿，自我更新和高度增殖。解决此问题的一种建议是 药理学上偏见的癌症干细胞的命运朝着末端分化的细胞命运。换句话说，驱动 癌症干细胞采用不会增殖的细胞命运，预期寿命短，也就是 对化疗敏感。实现这种分化疗法需要癌症的身份 已知干细胞，并且存在用于治疗入口点的候选分子靶标。为此， 富含亮氨酸的G蛋白偶联受体-5（LGR5）已被发现是结肠癌干细胞的标志物 并且是一个诱人的药物目标。 LGR5及其同源LGR4充当调节剂 Wnt/ßCatenin信号通路。 Wnt/ßcatenin信号传导是调节干细胞的关键途径 肠内稳态。该途径中的突变导致过量信号传导和强烈偏置干细胞 对长寿且高度增殖的癌症干细胞的行为。因此，lgr5很有吸引力 抵消这种失衡并恢复正常细胞命运动力学的药理目标。但是， LGR5信号及其在体内角色的机制仍然是投票，代表了一个主要的知识差距。 因此，该提案的目的是确定LGR5信号控制如何茎和癌症 干细胞命运。为了实现这一目标，我将检验抑制LGR5的中心假设 内部化会减轻Wnt/ßcatenin信号传导并促进癌症干细胞分化。三个具体 已经提出了目的来检验这一假设，并将在（AIM 1）阐明LGR5介导的机制 Wnt/ßcatenin信号传导，（AIM 2）阐明LGR5依赖的信号传导机制协调茎 细胞行为和（目标3）确定用于驱动癌症干细胞的小分子干预措施 分化。在本研究计划中描述了关键的初步发现，以实现 中心假设和特定目的。生物化学，细胞生物学，药理学和癌症的整合 生物学使这成为创新的研究建议。该建议很重要，因为它将改变LGR5 从干细胞标记到可以在药理学上针对控制的高价值药物候选者 癌症干细胞命运。我的研究和职业发展计划展示了跨学科培训 我收到的。这跨越了生物医学科学谱，包括干细胞生物学，分子 生物学，基因工程，癌症研究，生物化学，我们细胞分析和高通量筛查。 该NCI K22提案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。通过完成此建议，我将有能力获得 R01资金和朝着我的长期职业目标努力，以使高影响力和基础 可以转化为癌症治疗方法的发现。这样做，我将成为一个 NCI使命的工具组成部分“加速科学发现率并降低 美国和世界各地的癌症负担。”