Investigating L1CAM-dependent stem cell regeneration in metastasis

项目概要 由于能够自我修复的耐药亚克隆的出现，转移性癌症总是会复发。 更新、缓慢的细胞周期、肿瘤重新启动和治疗抵抗，称为转移干细胞（MetSC）。 然而，人们对 MetSC 生存和再生的分子机制知之甚少。初步 该提案中描述的数据将细胞粘附分子细胞粘附分子 L1 (L1CAM) 识别为 抑制转移复发的关键目标。采用新颖的源自患者的类器官治疗模型 抗性结直肠癌 (CRC) 肝转移，患者肿瘤中的 L1CAM 细胞被证明选择性地 离体再生类器官。 L1CAM 是体外类器官再生所必需的，而小鼠 体内结肠炎损伤后的结肠上皮。完整上皮结构中细胞与细胞接触的破坏是 L1CAM 诱导是必要且充分的，随着上皮细胞的生长，表达会随着时间的推移而减少 再生了。我们假设上皮不完整会诱导 L1CAM 表达，这是 癌细胞在侵袭、转移和治疗后的存活和再生。的机制 将使用源自患者的类器官模型定义 (1) 在肿瘤进展过程中诱导 L1CAM 依赖性 转移性 CRC 的研究确定上皮连接下游 L1CAM 的转录调控 解离和（2）使用基因工程小鼠模型，尖端的类器官衍生的原位 直肠移植以及体内原位肝和肺转移模型以确定 L1CAM 在 肿瘤发生、局部侵袭、转移定植和维持。拟议的调查将 描绘肿瘤传播诱导表型可塑性和出现的信号通路 转移特征，并将为抑制转移再生的 L1CAM 靶向药物铺平道路。的 申请人，Karuna Ganesh 博士，纪念斯隆凯特林胃肠肿瘤服务讲师 癌症中心 (MSKCC) 制定了一个基于她在以下领域的研究背景的 5 年职业计划： 肿瘤内科的生物化学和临床培训。该项目将为 Ganesh 博士提供理想的培训 使用具有临床代表性、最先进的患者来源的类器官和小鼠模型来剖析 转移的转录和表观遗传调控。 Ganesh 博士将接受 Joan Massagué 博士的指导，Joan Massagué 博士是一位 国际知名转移专家，拥有成功独立培训的良好记录 医师科学家。候选人的职业发展计划包括课程、研讨会、指导 由杰出的基础科学家和医学肿瘤学家组成的跨学科咨询委员会，以及 MSKCC 卓越的机构环境中的研究经验 转化癌症研究。该研究项目的成功完成将带来新的方法 治疗转移性癌症患者，将为 Ganesh 博士的过渡奠定基础 作为一名独立调查员，拥有自己的实验室和 R01 资助。

PROJECT SUMMARY Metastatic cancers invariably relapse due to the emergence of resistant subclones that are capable of self- renewal, slow cell-cycling, tumor re-initiation and therapy resistance, termed metastasis stem cells (MetSCs). Yet the molecular mechanisms MetSCs employ for survival and regrowth are poorly understood. Preliminary data described in this proposal identify the cell-adhesion molecule cell adhesion molecule L1 (L1CAM) as a critical target for suppressing metastatic relapse. Employing novel patient-derived organoid models of therapy- resistant colorectal cancer (CRC) liver metastases, L1CAM+ cells in patient tumors are shown to selectively regenerate organoids ex vivo. L1CAM is required for the regeneration of organoids in vitro, and the mouse colon epithelium after colitis injury in vivo. Disruption of cell-cell contact in intact epithelial structures is necessary and sufficient for L1CAM induction, with expression diminishing over time as the epithelium is regenerated. We hypothesize that epithelial disintegrity induces L1CAM expression, which is required for the survival and regrowth of cancer cells during invasion, metastasis and following therapy. The mechanisms that induce L1CAM dependency during tumor progression will be defined (1) using patient-derived organoid models of metastatic CRC to define the transcriptional regulation of L1CAM downstream of epithelial junction dissociation and (2) using genetically engineered mouse models, cutting-edge organoid-derived orthotopic rectal transplantation, and orthotopic liver and lung metastatic models in vivo to determine the role of L1CAM in tumor initiation, local invasion, metastatic colonization and maintenance. The proposed investigations will delineate signaling pathways by which tumor dissemination induces phenotypic plasticity and the emergence of metastatic traits, and will pave the way for L1CAM-targeting drugs that inhibit metastasis regeneration. The applicant, Dr. Karuna Ganesh, an Instructor in the Gastrointestinal Oncology Service at Memorial Sloan Kettering Cancer Center (MSKCC), has delineated a 5-year career plan that builds upon her research background in biochemistry and clinical training in medical oncology. This project will provide the ideal training for Dr. Ganesh in using clinically representative, state-of-the-art patient-derived organoid and mouse models to dissect the transcriptional and epigenetic regulation of metastasis. Dr. Ganesh will be mentored by Dr. Joan Massagué, an internationally renowned expert in metastasis with a strong track record of training successful independent physician scientists. The candidate's career development plan includes coursework, workshops, mentoring from an interdisciplinary advisory committee comprising distinguished basic scientists and medical oncologists, and research experience in the outstanding institutional environment of MSKCC, a center of excellence in translational cancer research. Successful completion of the research project will lead to new approaches for treating patients with metastatic cancer and will provide the foundation for Dr. Ganesh to transition to a position as an independent investigator with her own laboratory and R01 funding.