The Role of Basement Membrane Biomechanics in Cancer Cell Invasion

描述（由申请人提供）：本申请的目的是发展Aron Parekh博士作为癌症侵袭领域独立研究人员的职业生涯。PI和他的导师Alissa M.韦弗医学博士博士，和共同导师维托·夸兰塔医学博士结合了教学和实验室培训，以建立Parekh博士的生物学知识和技能。培训期间的最终目标是将联合收割机PI在力学和机械生物学方面的专业知识与导师在分子生物学和先进成像技术方面的专业知识相结合，使Parekh博士成为专注于癌细胞机械生物学机制的多学科研究人员。拟议的培训机会将为PI提供受保护的时间，以获得获得这些技能的宝贵知识和经验，使其能够在癌症侵袭方面取得成功。下文所述的研究提案是这一五年职业发展计划和未来供资提案的基础。 长期的临床结果取决于癌细胞是否通过上皮和邻近的间质组织迁移和侵入而离开原发肿瘤部位。癌症的侵袭性与体内和体外的组织密度和硬度有关。我们的实验室已经表明，刚性底物的机械传感与细胞外基质（ECM）降解增加相关，这是由于侵入伪足（invadopodia）的活性升高，细胞骨架结构被认为是蛋白水解入侵的关键。因此，这些结果表明，机械因素如张力在驱动恶性表型中起重要作用。然而，生物力学和实际组织的入侵之间的联系仍然是不确定的，由于缺乏在体外模型，模仿真正的组织特性，特别是那些上皮基底膜（BM）和基质。在体内，由肿瘤细胞填塞和促结缔组织增生基质产生的机械力导致乳腺中的刚性或张力增加以及局部ECM（包括BM和邻接基质）的机械负荷增加。因此，施加在局部ECM上的机械力可能在调节侵袭性表型中起重要作用，但目前还没有研究在模拟肿瘤微环境的条件下测试ECM生物力学的作用。目的是确定这些外力在调节癌细胞迁移和通过ECM侵袭中的作用。为实现这一目标，提出了三个具体目标。在具体目标1中，将表征ECM支架膀胱基质-BM（UBM-BM）的化学、物理和机械性质，以将该材料确立为生理学相关的体外ECM模型。在特定目标2中，BM张力激活促进侵袭的恶性表型的假设将通过检查侵袭性癌细胞在张力下UBM-BM的渗透来测试。相比之下，Specific Aim 3将通过利用UBM-BM的结缔组织组分作为基质的模型来测试通过相邻基质组织的侵袭是否独立于蛋白水解降解和/或机械感应而发生。Parekh博士预计，这些研究将对机械激活癌细胞穿透BM和基质的机制产生重要的见解，并可能为干扰这些过程的新型治疗策略打开大门。 公共卫生相关性：起源于乳腺并侵入身体其他部位的癌细胞仍然是一个具有挑战性的临床问题，严重影响患者的长期生存率。机械因素现在被认为在驱动癌细胞离开原发肿瘤部位、侵入邻近组织并最终扩散到全身中起着至关重要的作用。为了开发新的医学疗法来预防癌细胞侵袭并显著影响患者的预后，必须首先阐明机械因素调节癌细胞侵袭的机制。

DESCRIPTION (provided by applicant): The objective of this application is to develop the career of Dr. Aron Parekh as an independent researcher in the field of cancer invasion. The career development plan created by the PI and his mentor Alissa M. Weaver, M.D., Ph.D., and co-mentor Vito Quaranta, M.D., combines both the didactic and laboratory training required to build Dr. Parekh's biological knowledge and skills. The ultimate goal of the training period is to combine the PI's expertise in mechanics and mechanobiology with the mentors' expertise in molecular biology and advanced imaging techniques to equip Dr. Parekh to become a multidisciplinary researcher focused on the mechanisms of cancer cell mechanobiology. The proposed training opportunity would provide the PI protected time to gain valuable knowledge and experience in acquiring these skills to position him for a successful career in cancer invasion. The research proposal, described below, serves as the foundation of this five year career development plan and of future funding proposals. Long-term clinical outcomes are dependent on whether carcinoma cells leave the primary tumor site by migrating and invading through epithelial and adjacent stromal tissues. Cancer aggressiveness has been linked to tissue density and rigidity both in vivo and in vitro. Our laboratory has shown that mechanosensing of rigid substrates is correlated to increased extracellular matrix (ECM) degradation due to elevated activity of invadopodia, the cytoskeletal structures thought to be critical for proteolytic invasion. Therefore, these results suggest that mechanical factors such as tensile forces play an important role in driving a malignant phenotype. However, the link between biomechanics and the invasion of actual tissues remains inconclusive due to the lack of in vitro models that mimic true tissue properties, particularly those of the epithelial basement membrane (BM) and stroma. In vivo, mechanical forces generated by tumor cell packing and the desmoplastic stroma lead to increased rigidity or tension in the mammary gland and mechanical loading of the local ECM including the BM and adjoining stroma. Therefore, mechanical forces exerted on the local ECM may play an important role in regulating the invasive phenotype, but currently no studies have tested the role of ECM biomechanics under conditions that simulate the tumor microenvironment. The goal is to determine the role of these external forces in regulating cancer cell migration and invasion through the ECM. To achieve this goal, three specific aims are proposed. In Specific Aim 1, the chemical, physical, and mechanical properties of the ECM scaffold urinary bladder matrix-BM (UBM-BM) will be characterized to establish this material as a physiologically relevant in vitro ECM model. In Specific Aim 2, the hypothesis that BM tension activates a malignant phenotype that facilitates invasion will be tested by examining the penetration of UBM-BM under tension by invasive cancer cells. In contrast, Specific Aim 3 will test whether invasion through the adjacent stromal tissue occurs independent of proteolytic degradation and/or mechanosensing by utilizing the connective tissue component of UBM-BM as a model for the stroma. Dr. Parekh anticipates that these studies will yield important insight into the mechanism responsible for mechanically activating cancer cells to penetrate the BM and stroma and could open the door for novel therapeutic strategies that interfere with these processes. PUBLIC HEALTH RELEVANCE: Project Narrative Cancer cells that originate in the breast and invade other parts of the body continue to be a challenging clinical problem that severely affects the long-term survival rates of patients. Mechanical factors are now thought to play a crucial role in driving cancer cells to leave the primary tumor site, invade neighboring tissue, and eventually spread throughout the body. In order to develop new medical therapies to prevent cancer cell invasion and significantly impact patient outcomes, the mechanism by which mechanical factors regulate cancer cell invasion must first be elucidated.