Functional exploration of progenitor renewal and differentiation in oral epithelial homeostasis and cancer

口腔上皮稳态和癌症中祖细胞更新和分化的功能探索

• 批准号: 10677648
• 负责人: ZHE YING
• 金额: $ 24.56万
• 依托单位: ICAHN SCHOOL OF MEDICINE AT MOUNT SINAI
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-09-02 至 2024-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10677648
• 关键词: Acceleration; Apoptosis; Bar Codes; Binding; Bioinformatics; Biological Assay; Candidate Disease Gene; Cell Cycle; Cell Cycle Arrest; Cell Cycle Regulation; Cell Differentiation process; Cells; Chromosomes; Clonal Expansion; Data; Development; Disadvantaged; Epithelial Cells; Epithelium; Exposure to; Foundations; Future; Gene Expression Profile; Genes; Genetic; Genetic Screening; Genetic Transcription; Goals; Growth; Head and Neck Squamous Cell Carcinoma; Homeostasis; Human papilloma virus infection; Injections; Knowledge; Lentivirus; Lesion; Maintenance; Malignant Neoplasms; Measures; Mediating; Mitotic; Modeling; Molecular; Mus; Mutate; Mutation; Oncogenes; Oncogenic; Oral; PIK3CA gene; PIK3CG gene; Pathway interactions; Patients; Pattern; Phase; Placenta; Population; Publishing; Research; Research Personnel; Signal Induction; Signal Transduction; Stratified Epithelium; Stromal Cells; TP53 gene; Testing; Tissues; Tobacco use; Training; Tumor Promotion; Work; cancer type; craniofacial; epithelial stem cell; genome-wide; improved; in vivo; inflammatory milieu; insight; knockin animal; maxillofacial; multiple omics; mutant; new therapeutic target; novel; novel therapeutic intervention; oral cavity epithelium; oral tumorigenesis; patient prognosis; postmitotic; progenitor; programs; promoter; senescence; stem cell fate; stem cell niche; stem cells; tumor; tumor initiation; tumor microenvironment; tumorigenesis

Project Summary Head and neck squamous cell carcinoma (HNSCC) is the most common cancer type initiated from stratified epithelium of oral and maxillofacial region. Despite great effort to characterize HNSCC via high throughput multi-omics approaches, significant improvements in patient prognosis are yet to be made. This is largely due to incomplete understanding of how cancer-associated lesions reprogram epithelial cells to expand and transform, at cellular and molecular levels. Stratified epithelium is a tissue characterized by (a) highly proliferative basal progenitor cells, (b) progenitor differentiation which is accompanied by complete loss of mitotic potential, and (c) stem cell fate choice between the proliferative progenitor and differentiated postmitotic states. As such, growth rate of stratified epithelia is controlled by balancing rates of renewal and differentiation. In my recently published work, I found that oncogenic activation of Pik3ca, the most commonly mutated oncogene in HNSCC, results in growth disadvantage in stratified epithelia. Using direct measure of cell fate choice in vivo, I found that oncogenic PI3K signaling induces differentiation. This serves to counterbalance accelerated cell cycle independently of senescence or apoptosis, and acts as a dominant cellular mechanism to restrict clonal expansion. Building on that study, my current proposal will test the hypothesis that genetic lesions and niche factors found in PI3K mutant HNSCC promote tumorigenesis by overcoming oncogene- induced differentiation. In my preliminary work I used multiple rounds of genetic screens in vivo to identify renewal promoters among ~500 patient-derived lesions associated with PIK3CA mutations. Through this large- scale effort I identified the minimal combination of lesions required to overcome PI3K induced differentiation and initiate HNSCC formation. Among these lesions, loss of Trp53 acts as a primary renewal promoter. Using a canonical p53 function deficient Trp533KR/3KR knock-in animal, I found that Trp53 loss drives HNSCC by promoting renewal, and independent of cell cycle arrest, senescence and apoptosis. By comparing chromosome accessibility between WT, Trp533KR/3KR and Trp53-/- epithelium I found that p53 can transcriptionally suppress key renewal genes, and I propose to study the importance of these genes for p53- mediated progenitor differentiation. In parallel, I identified secretory factors specifically expressed in HNSCC progenitor niche. I used a genetic screen to test their potential to overcome PI3K induced differentiation. With a novel intra-placenta lentivirus injection strategy, I am able to infect a spectrum of stromal cells present in niche of stratified epithelium. Thus, I will functional test key pro-renewal factors in stromal cells during HNSCC initiation to uncover the underlying molecular pathways mediating epithelial renewal. In summary, my preliminary data identify key genetic lesions and secreted niche factors that may drive HNSCC formation by overcoming PI3K induced differentiation. My proposal will continue to test this model, with the ultimate goal of uncovering molecular mechanism of how PI3K induced differentiation barrier is breached in HNSCCs.

项目摘要 头颈鳞状细胞癌（HNSCC）是从分层开始的最常见的癌症类型 口腔和上颌面区的上皮。尽管竭尽全力通过高通量来表征HNSCC 多词的方法，尚未进行大幅改善患者预后。这主要是由于 为了不完整了解与癌症相关病变如何重新编程上皮细胞扩展和 在细胞和分子水平上转化。分层上皮是（a）高度特征的组织 增殖性基底祖细胞，（b）祖细胞分化，伴随着完全损失 有丝分裂电位，以及（c）增生祖细胞和分化的有丝分裂的干细胞命运选择 国家。因此，分层上皮的生长速率通过平衡更新和分化的速率控制。 在我最近发表的工作中，我发现PIK3CA的致癌激活是最常见的突变 HNSCC中的癌基因导致分层上皮的生长劣势。使用直接测量细胞命运 选择在体内，我发现致癌PI3K信号传导诱导分化。这有助于平衡 加速细胞周期独立于衰老或凋亡，充当主要的细胞机制 限制克隆扩张。在这项研究的基础上，我目前的提议将检验遗传的假设 PI3K突变体HNSCC中发现的病变和利基因子通过克服癌基因 - 诱导的分化。在我的初步工作中，我在体内使用了多个遗传筛选来识别 与PIK3CA突变有关的约500个患者衍生病变中的更新启动子。通过这个大的 比例尺努力我确定了克服PI3K诱导分化所需的病变的最小组合 并启动HNSCC组。在这些病变中，TRP53的损失是主要更新启动子。使用 规范p53功能缺乏TRP533KR/3KR敲击动物，我发现TRP53损失驱动HNSCC 促进更新，独立于细胞周期停滞，衰老和凋亡。通过比较 WT，TRP533KR/3KR和TRP53 - / - 上皮之间的染色体可及性，我发现p53可以 转录抑制关键更新基因，我建议研究这些基因对p53-的重要性 介导的祖细胞分化。同时，我确定了在HNSCC中专门表达的分泌因子 祖细胞利基。我使用遗传筛选来测试其克服PI3K诱导分化的潜力。与 新型的静脉内慢病毒注射策略，我能够感染一系列存在于小众中的基质细胞 分层上皮。因此，我将在HNSCC期间的基质细胞中功能性测试关键启动恢复因子 揭示介导上皮更新的潜在分子途径的启动。总而言之，我的 初步数据确定了关键的遗传病变和分泌的利基因素，这些因素可能会通过 克服PI3K诱导分化。我的建议将继续测试该模型，最终目标是 在HNSCC中漏洞，发现PI3K诱导的分化屏障的分子机制。