MECHANOSURVEILLANCE IN BREAST CANCER METASTASIS

项目总结/摘要-乳腺癌转移的力学监测 转移性乳腺癌是一种毁灭性的疾病，影响着成千上万的妇女的生活， 年不幸的是，大多数被诊断患有转移性乳腺癌的患者的治疗选择是 姑息治疗目前的治疗策略通常针对癌细胞的遗传和生化异常， 癌细胞在其生物物理性质如细胞硬度方面也经历深刻的变化。靶向 生物物理特性提供了令人兴奋的新的治疗途径，但对关系的基本知识 癌细胞硬度和转移调节之间的关系是不完全的。新出现的证据表明 癌细胞硬度作为一种机械输入，激活细胞毒性淋巴细胞，破坏癌症 细胞因此，僵硬成为癌细胞在转移级联过程中的免疫脆弱性。这 机械输入激活免疫监视的过程称为机械监视， 在癌症中受肌钙蛋白相关转录因子A和B（MRTFA/B）表达的强烈调节 细胞根据已公布的数据和初步数据，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，从而激活了细胞周期中的机械监视。 乳腺癌转移本项目的长期目标是确定MRTFA的分子介质 相关的机械监视，从而告知药理学方法来利用这种癌细胞 更好地治疗转移性乳腺癌患者。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组学和基因组学分析 模型，原子力显微镜对患者来源的异种移植类器官（PDXos）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 该项目的目标是： 1)为了确定MRTFA驱动的钙内流对PDXos中癌细胞硬度的贡献， 体外和原位小鼠模型，通过使用原子力显微镜和共聚焦显微镜。 2)确定MRTFA的细胞毒性淋巴细胞活化程度和相关硬度 通过对来自患者的转移性组织样本使用多路成像和机器学习， 通过使用流式细胞术在同基因小鼠模型中的转移。 3)确定如何利用MRTFA相关的机械监测，通过测试靶向转移， 临床相关免疫检查点阻断治疗对携带转移瘤的小鼠的影响。 这项工作将揭示机械监视的介质，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阻断的直接使用和未来 增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.