Interplay between Cdh1 and major regulatory pathways in human cancer

Cdh1 与人类癌症主要调控途径之间的相互作用

• 批准号: 8957724
• 负责人: Wenyi Wei
• 金额: $ 33.5万
• 依托单位: BETH ISRAEL DEACONESS MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-08-06 至 2019-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8957724
• 关键词: Animal Model; Automobile Driving; Biochemical; Biological; Cell Culture Techniques; Cell Cycle; Cell Cycle Progression; Cell Cycle Regulation; Cell physiology; Cells; Complex; Cyclin D1; DNA Repair; Data; Development; Dimerization; Dissociation; Engineering; Family member; G1 Phase; Genetic; Genomic Instability; Human; In Vitro; Laboratories; Lead; MEKs; Malignant Neoplasms; Mediating; Melanoma Cell; Mitosis; Molecular; Mutation; Oncogenic; PTEN gene; Pathologic Processes; Pathway interactions; Phosphorylation; Phosphotransferases; Play; Publishing; Regulation; Regulatory Pathway; Resistance; Role; Signal Pathway; Signal Transduction; Tumor Suppression; Tumor Suppressor Genes; Tumor Suppressor Proteins; Ubiquitin; Ubiquitination; anaphase-promoting complex; base; cancer cell; cancer therapy; carcinogenesis; dimer; genome integrity; in vivo; inhibitor/antagonist; insight; malignant breast neoplasm; melanoma; mouse model; novel; osteoblast differentiation; premature; public health relevance; senescence; therapeutic target; tumor; tumorigenesis; ubiquitin-protein ligase

 DESCRIPTION (provided by applicant): Defective cell cycle regulation leads to genomic instability and ultimately cancer development. The Anaphase Promoting Complex (APC) regulates cell cycle progression by forming two distinct sub-complexes, APCCdh1 and APCCdc20, to promote the timely ubiquitination and degradation of various cell cycle regulators. The APC activator Cdh1 has been implicated in tumorigenesis, while its exact roles in tumor suppression remain largely unclear. Therefore, the primary objective of this proposal will be to continue our previous efforts in examining both in vitro and in vivo how Cdh1 functions to block cancer development and progression by its interplay with multiple major tumor suppressor and oncogenic pathways. We previously published that APC- free Cdh1 could augment the catalytic activity of HECT domain-containing E3 ligase Smurf1 to regulate osteoblast differentiation. Furthermore, we obtained preliminary results showing that in addition to Smurf1, Cdh1 could also modulate the E3 ligase activity of WWP2, another NEDD4 family member, in an APC- independent manner. More importantly, we showed that depletion of Cdh1 enhanced WWP2-mediated degradation of its ubiquitin substrate, PTEN. In Aim #1, we propose to use multiple genetic and biochemical approaches to identify the novel APC-independent molecular mechanism(s) by which Cdh1 controls WWP2 E3 ligase activity to govern timely degradation of PTEN, and to evaluate whether elevation of Akt signaling has a critical role in loss of Cdh1-mediated cancer development in vivo. In Aim #2, we will characterize a multi- mechanistic role for Cdh1 in inhibiting tumorigenesis by suppressing BRaf activity. Our preliminary data reveal Cdh1 as a novel negative regulator of the BRaf/ERK oncogenic signaling through multiple mechanisms in a context-dependent manner. In primary cells, APCCdh1 earmarks BRaf for ubiquitination-mediated destruction, while in cancer cells, Cdh1 inhibits BRaf kinase activity largely by disrupting BRaf dimers in an APC- independent manner. In this Specific Aim, we will further characterize the molecular mechanism by which APCCdh1 targets BRaf for ubiquitination-mediated degradation. We will also examine how APC-free Cdh1 may inhibit BRaf dimerization leading to decreased ERK activity to influence tumorigenesis. Furthermore, we will also identify a possible dual regulatory mechanism in BRafV600E melanoma cells where both elevated activity of ERK and Cdk4/CyclinD1 may inhibit APCCdh1 by directly phosphorylating Cdh1. More importantly, using multiple in vitro cell culture and in vivo engineered animal models, we will further determine the significance of both APC-dependent and -independent regulatory pathways in mediating the tumor suppressive capabilities of Cdh1. Altogether, the proposed studies will not only provide novel mechanistic insights into the role of Cdh1 in tumorigenesis, but will also offer the rationale and molecular basis for the development of targeted therapeutics to inhibit downstream targets of Cdh1 such as WWP2 in modulating PTEN/Akt signaling (Aim #1) in breast cancer setting, and BRaf/ERK signaling (Aim #2) that plays driving roles in melanoma development.

 描述（由申请人提供）：细胞周期调节缺陷导致基因组不稳定并最终导致癌症发展。后期促进复合物 (APC) 通过形成两个不同的子复合物 APCCdh1 和 APCCdc20 来调节细胞周期进程，以促进各种细胞周期调节因子的及时泛素化和降解。 APC 激活剂 Cdh1 与肿瘤发生有关，但其在肿瘤抑制中的确切作用仍不清楚。因此，本提案的主要目标是继续我们之前的努力，在体外和体内检查 Cdh1 如何通过其与多种主要肿瘤抑制因子和致癌途径的相互作用来阻止癌症的发生和进展。我们之前发表过，不含 APC 的 Cdh1 可以增强含有 HECT 结构域的 E3 连接酶 Smurf1 的催化活性，从而调节成骨细胞分化。此外，我们获得的初步结果表明，除了Smurf1之外，Cdh1还可以以不依赖于APC的方式调节另一个NEDD4家族成员WWP2的E3连接酶活性。更重要的是，我们发现 Cdh1 的耗竭增强了 WWP2 介导的泛素底物 PTEN 的降解。在目标#1中，我们建议使用多种遗传和生化方法来鉴定新的独立于APC的分子机制，Cdh1通过该机制控制WWP2 E3连接酶活性以控制PTEN的及时降解，并评估Akt信号传导的升高是否在体内Cdh1介导的癌症发展的丧失中具有关键作用。在目标#2中，我们将描述 Cdh1 通过抑制 BRaf 活性来抑制肿瘤发生的多重机制作用。我们的初步数据表明，Cdh1 通过多种机制以上下文相关的方式作为 BRaf/ERK 致癌信号传导的新型负调节因子。在原代细胞中，APCCdh1 标记 BRaf 进行泛素化介导的破坏，而在癌细胞中，Cdh1 主要通过以不依赖于 APC 的方式破坏 BRaf 二聚体来抑制 BRaf 激酶活性。在这个具体目标中，我们将进一步描述 APCCdh1 靶向 BRaf 进行泛素化介导降解的分子机制。我们还将研究不含 APC 的 Cdh1 如何抑制 BRaf 二聚化，导致 ERK 活性降低，从而影响肿瘤发生。此外，我们还将确定 BRafV600E 黑色素瘤细胞中可能的双重调节机制，其中 ERK 和 Cdk4/CyclinD1 活性的升高可能通过直接磷酸化 Cdh1 来抑制 APCCdh1。更重要的是，利用多种体外细胞培养和体内工程动物模型，我们将进一步确定APC依赖性和非依赖性调节途径在介导Cdh1肿瘤抑制能力中的重要性。总而言之，拟议的研究不仅将为 Cdh1 在肿瘤发生中的作用提供新的机制见解，而且还将为开发靶向治疗方法提供基本原理和分子基础，以抑制 Cdh1 的下游靶标，例如在乳腺癌环境中调节 PTEN/Akt 信号传导（目标 #1）的 WWP2，以及在乳腺癌中发挥驱动作用的 BRaf/ERK 信号传导（目标 #2）。 黑色素瘤的发展。