The Role of Basement Membrane Biomechanics in Cancer Cell Invasion

描述(由申请人提供)：本申请的目标是发展Aron Parekh博士作为癌症侵袭领域的独立研究员的职业生涯。这项职业发展计划由PI和他的导师Alissa M.Weaver医学博士和共同导师Vito Quaranta医学博士创建，结合了建立Parekh博士的生物学知识和技能所需的教学和实验室培训。培训的最终目标是将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结合起来，使Parekh博士成为一名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，以便在获得这些技能方面获得宝贵的知识和经验，为他在癌症侵袭领域的成功职业生涯奠定基础。下文所述的研究提案是这项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间质组织的迁移和侵袭离开原发肿瘤部位。在体内和体外，肿瘤的侵袭性都与组织密度和硬度有关。我们的实验室已经证明，刚性底物的机械传感与细胞外基质(ECM)降解的增加有关，这是由于内生孢子的活性增加，这种细胞骨架结构被认为是蛋白质分解入侵的关键。因此，这些结果表明，机械因素，如拉力，在驱动恶性表型方面起着重要作用。然而，生物力学和实际组织侵袭之间的联系仍然不确定，因为缺乏模拟真实组织特性的体外模型，特别是上皮基底膜和基质的特性。在体内，肿瘤细胞堆积和促结缔组织间质产生的机械力导致乳腺刚性或张力增加，局部ECM包括BM和邻近间质的机械负荷增加。因此，施加在局部ECM上的机械力可能在调节侵袭表型方面发挥重要作用，但目前还没有研究在模拟肿瘤微环境的条件下测试ECM的生物力学作用。我们的目标是确定这些外力在通过ECM调节癌细胞迁移和侵袭中的作用。为了实现这一目标，提出了三个具体目标。在具体目标1中，对细胞外基质支架-膀胱基质-BM(UBM-BM)的化学、物理和力学性能进行表征，以建立该材料作为一种生理相关的体外ECM模型。在具体目标2中，将通过检测侵袭性癌细胞在张力下对UBM-BM的穿透来检验BM张力激活促进侵袭的恶性表型的假设。相比之下，特殊目标3将利用UBM-BM的结缔组织成分作为基质的模型，测试是否通过邻近基质组织的侵袭独立于蛋白降解和/或机械感知。帕雷克博士预计，这些研究将为机械激活癌细胞穿透骨髓和基质的机制提供重要的见解，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：项目叙述起源于乳房并侵袭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存活率。机械因素现在被认为在驱使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的过程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.