MECHANOSURVEILLANCE IN BREAST CANCER METASTASIS

项目摘要/摘要-乳腺癌转移的机制研究 转移性乳腺癌是一种毁灭性的疾病，影响着数以万计的女性的生活。 年。不幸的是，被诊断为转移性乳腺癌的患者的大多数治疗方案是 治标不治本。目前的治疗策略通常针对癌细胞的遗传和生化异常，但 癌细胞的生物物理性质也发生了深刻的变化，如细胞僵硬。瞄准 生物物理特性提供了令人兴奋的新治疗途径，但关于这种关系的基本知识 癌细胞僵硬和转移调控之间的关系是不完整的。新出现的证据表明 癌细胞的僵硬作用是激活细胞毒性淋巴细胞的机械输入，而细胞毒性淋巴细胞可以摧毁癌症 细胞。因此，僵硬成为癌细胞在转移级联过程中的一种免疫脆弱性。这 机械输入激活免疫监视的过程称为机械监视，它是 肌钙蛋白相关转录因子A和B(MRTFA/B)在肿瘤中的表达 细胞。根据已公布的和初步的数据，该项目的总体假设是 MRTFA驱动的钙内流增加了癌细胞的硬度，从而激活了 乳腺癌转移。该项目的长期目标是确定MRTFA的分子介体。 相关的机械监视，从而为利用这种癌细胞的药理学方法提供信息 更好地治疗转移性乳腺癌患者的脆弱性。研究设计包括一套 跨学科的方法，如患者样本和癌症的转录和基因组分析 患者来源的异种移植有机物(PDXos)的模型、原子力显微镜和免疫活性 转移定植模型和人乳腺癌转移的组织学分析。具体的 该项目的目标是： 1)确定MRTFA驱动的钙内流对PDXos癌细胞硬度的贡献。 用原子力显微镜和共聚焦显微镜建立小鼠体外模型和原位模型。 2)用MRTFA测定细胞毒性淋巴细胞的活化程度及其相关的僵硬 在活体中，使用多路成像和机器学习对来自患者和 用流式细胞术检测同基因小鼠模型中的转移瘤。 3)通过试验确定如何利用MRTFA相关的机械监测来靶向转移 临床相关免疫检查点阻断治疗对荷瘤小鼠的影响。 这项工作将揭示机械监测的媒介，并证明其在人类癌症中的流行。 因此，这项工作的结果将影响免疫检查点封锁的立即使用和未来 加强转移性乳腺癌患者机械监测的策略。

PROJECT SUMMARY/ABSTRACT - MECHANOSURVEILLANCE IN BREAST CANCER METASTASIS Metastatic breast cancer is a devastating disease that impacts the lives of tens of thousands of women each year. Unfortunately, the majority of treatment options for patients diagnosed with metastatic breast cancer are palliative. Current treatment strategies often target cancer cells’ genetic and biochemical abnormalities, but cancer cells also undergo profound changes in their biophysical properties such as cellular stiffness. Targeting biophysical properties offers exciting new therapeutic avenues, but the basic knowledge on the relationship between cancer cell stiffness and regulation of metastasis is incomplete. Emerging evidence suggests that cancer cell stiffness acts as a mechanical input for activation of cytotoxic lymphocytes that destroy cancer cells. Thereby, stiffness becomes an immune vulnerability of cancer cells during the metastatic cascade. This process, where mechanical inputs activate the immune surveillance, is termed mechanosurveillance and it is strongly regulated by the expression of Myocardin related transcription factors A and B (MRTFA/B) in cancer cells. Based on the published and the preliminary data, the overarching hypothesis of this project is that MRTFA driven calcium influx increases cancer cell stiffness and thereby activates mechanosurveillance during breast cancer metastasis. The long-term goal of this project is to determine the molecular mediators of MRTFA associated mechanosurveillance and thereby inform pharmacological methods to exploit this cancer cell vulnerability for better treatment of patients with metastatic breast cancer. The research design includes a set of interdisciplinary approaches, such as transcriptomic and genomic analyses of patient samples and cancer models, atomic force microscopy on patient derived xenograft organoids (PDXos) and on immunocompetent models of metastatic colonization, and histological analyses of human breast cancer metastases. The specific aims of this project are: 1) to determine the contribution of MRTFA driven calcium influx on cancer cell stiffness in PDXos, in vitro, and in situ mouse models by using atomic force microscopy and confocal microscopy. 2) to determine the degree of cytotoxic lymphocyte activation by MRTFA and the associated stiffness in vivo by using multiplexed imaging and machine learning on metastatic tissue samples from patients and by using flow cytometry in metastases in syngeneic mouse models. 3) to determine how to exploit MRTFA associated mechanosurveillance to target metastases by testing the impact of clinically relevant immune checkpoint blockade treatments on metastasis bearing mice. This work will uncover mediators of mechanosurveillance and demonstrate its prevalence in human cancer. Thus, results of this work will impact the immediate use of immune checkpoint blockade and the future strategies to enhance mechanosurveillance in patients with metastatic breast cancer.