ESCRT-dependent novel regulatory mechanism of EMT and tumorigenesis in oral cancer

口腔癌 EMT 和肿瘤发生的 ESCRT 依赖性新调控机制

基本信息

批准号：
10391608
负责人：
Radhika Gudi
金额：
$ 37.75万
依托单位：
MEDICAL UNIVERSITY OF SOUTH CAROLINA
依托单位国家：
美国
项目类别：
财政年份：
2022
资助国家：
美国
起止时间：
2022-09-01 至 2027-05-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10391608
关键词：
ATP phosphohydrolase Binding Biogenesis Biological Carrier Proteins Cell Line Cells Centrioles Centrosome Chemoresistance Clinical Complex Continuous Positive Airway Pressure Data Defect Development Down-Regulation Drug Targeting Endocytic Vesicle Endocytosis Endosomes Epidermal Growth Factor Receptor Epithelial Event Exploratory/Developmental Grant for Diagnostic Cancer Imaging Generations Genetic Models Goals Growth Homeostasis Knock-in Mouse Knock-out Knockout Mice Knowledge Lead Ligands Link Lysosomes Malignant - descriptor Malignant Epithelial Cell Malignant Neoplasms Manuscripts Mediating Mediator of activation protein Mesenchymal Microtubules Molecular Multivesicular Body Mutagenesis Neoplasm Metastasis Nitroquinolines Oral Oxides Pathway interactions Patients Phenotype Physiological Predisposition Prevention Preventive Property Protein Overexpression Proteins Receptor Down-Regulation Receptor Signaling Recurrence Regulation Resistance Role Route Signal Transduction Solid Sorting - Cell Movement Structure Surface Testing Time Tissues Translating Tubulin Tubulin Interaction Tumor Suppressor Proteins Tumorigenicity Unfavorable Clinical Outcome Vesicle base cancer cell cancer stem cell epithelial to mesenchymal transition loss of function malignant mouth neoplasm mouth squamous cell carcinoma novel oral carcinogenesis oral tumorigenesis overexpression prevent protein function receptor receptor expression recruit therapeutic target trafficking tumor tumor progression tumorigenesis tumorigenic vesicle transport

项目摘要

PROJECT DESCRIPTION/ABSTRACT Epidermal growth factor receptor (EGFR) is overexpressed in majority of tumors including oral squamous cell carcinoma (OSCC). The over-expressed/-activated EGFR contributes to epithelial-mesenchymal transition (EMT) and tumor progression by contributing to tumor metastasis and chemo-resistance. Hence, EGFR has become one of the major therapeutic targets for OSCC. Endocytosis is a key biological pathway for internalization of ligand activated EGFR, following which it gets routed for lysosomal degradation by the endosomal sorting complex for recruitment and transport (ESCRT) machinery. ESCRT is a key mediator of endocytic vesicle trafficking (EVT). While vesicle trafficking defects result in the poor downregulation of activated EGFR, persistent surface and cellular EGFR expression and signaling is subsequently linked to the development of cancer. Surprisingly, the molecular events/mechanisms that regulate ESCRT pathway which is critical for maintaining EGFR homeostasis and preventing EMT and tumorigenesis are largely unknown. Here, based on solid preliminary data, we propose to investigate a previously unknown mechanism that regulates ESCRT dependent EVT, EGFR levels and signaling, EMT, and OSCC growth. We found that 1) depletion of CPAP caused the prolonged expression of EGFR and an EMT-like phenotype in oral cancer cells; 2) while depletion of CPAP enhanced the tumorigenicity of an OSCC cell line, overexpression of CPAP in this cell line suppressed its tumor inducing potential; 3) overexpression of CPAP caused the de novo generation of EGFR- positive multivesicular bodies, whose biogenesis requires ESCRT and are essential intermediates that route EGFR to lysosomes for degradation and termination of its signaling; and 4) the absence of CPAP resulted in diminished cellular levels of VPS4 protein, an essential ESCRT associated ATPase that facilitates pinching off of endocytic vesicles. These collective observations suggest that CPAP induced positive regulation of ESCRT pathway and EVT maintains EGFR homeostasis, resulting in prevention of EMT and tumorigenesis in OSCC. This novel hypothesis will be tested systematically under two specific aims. The primary goals of aim 1 will be to define the molecular mechanisms by which CPAP positively regulates EVT and EGFR homeostasis in OSCC. This will be done by using OSCC and normal oral cells with gain-and-loss-of-function of CPAP as well as by studying CPAP-ESCRT interaction in the context of EGFR homeostasis. We will then, under aim 2, determine the role of CPAP in preventing EMT and oral tumorigenesis. This will be achieved by characterizing CPAP gain- and-loss-of-function in OSCC cell lines for EMT features, and growth and tumorigenic properties, and by studying the oral cancer susceptibility using a conditional CPAP-knockout mice. Overall, this study will delineate a novel ESCRT dependent mechanism that prevents OSCC.

项目描述/摘要表皮生长因子受体（EGFR）在包括口腔鳞状细胞在内的大多数肿瘤中过度表达癌（OSCC）。过度表达/激活的 EGFR 有助于上皮间质转化（EMT）和肿瘤进展通过促进肿瘤转移和化疗耐药性。因此，EGFR 成为OSCC的主要治疗靶点之一。内吞作用是内化的关键生物学途径配体激活 EGFR，随后通过内体分选被路由至溶酶体降解招募和运输（ESCRT）机械综合体。 ESCRT 是内吞囊泡的关键介质贩运（EVT）。虽然囊泡运输缺陷导致激活的 EGFR 下调不佳，但持续存在表面和细胞 EGFR 表达和信号转导随后与癌症的发展相关。令人惊讶的是，调节 ESCRT 途径的分子事件/机制对于维持 EGFR 稳态以及预防 EMT 和肿瘤发生在很大程度上尚不清楚。在这里，基于可靠的初步数据，我们建议研究一种以前未知的调节机制 ESCRT 依赖性 EVT、EGFR 水平和信号传导、EMT 和 OSCC 生长。我们发现 1) 耗尽 CPAP 导致口腔癌细胞中 EGFR 表达延长并出现 EMT 样表型； 2）同时 CPAP 的耗竭增强了 OSCC 细胞系的致瘤性，该细胞系中 CPAP 的过度表达抑制其诱发肿瘤的潜力； 3）CPAP的过度表达导致EGFR-的从头生成阳性多泡体，其生物发生需要 ESCRT，并且是路线的重要中间体 EGFR 进入溶酶体，降解并终止其信号传导； 4) 缺乏 CPAP 导致 VPS4 蛋白的细胞水平降低，VPS4 蛋白是一种重要的 ESCRT 相关 ATP 酶，有助于夹断内吞囊泡。这些集体观察结果表明 CPAP 诱导 ESRT 的正向调节途径和 EVT 维持 EGFR 稳态，从而预防 OSCC 中的 EMT 和肿瘤发生。这一新颖的假设将在两个特定目标下进行系统测试。目标 1 的主要目标是定义了 CPAP 积极调节 OSCC 中 EVT 和 EGFR 稳态的分子机制。这将通过使用 OSCC 和具有 CPAP 功能获得和丧失功能的正常口腔细胞以及通过研究 EGFR 稳态背景下 CPAP-ESCRT 相互作用。然后，我们将在目标 2 下确定 CPAP 在预防 EMT 和口腔肿瘤发生中的作用。这将通过表征 CPAP 增益来实现 OSCC 细胞系中 EMT 特征、生长和致瘤特性的功能丧失，并通过研究使用条件性 CPAP 基因敲除小鼠研究口腔癌的易感性。总的来说，这项研究将描绘一部小说防止 OSCC 的 ESCRT 依赖机制。