Collaborative Research: Heterogeneous Cancer Cell Mechanics Differentially Drives Mechanosensing and Migration

实体瘤中的癌细胞必须分离、迁移和侵袭周围组织才能转移。这一过程由细胞外基质的性质调节，包括它的硬度和它与肿瘤细胞的粘附力。但肿瘤并不是同质的，这些肿瘤细胞对环境的反应可能会有所不同。这个项目将研究细胞黏附特性的变化如何影响细胞的命运，特别是它们是否会迁移、增殖、分化或死亡--这些都是细胞行为的关键部分。这个项目将加强对细胞机械特性变化如何影响广泛的细胞行为的基本理解。一旦这些知识被扩展，它就可以用来影响组织水平上的细胞行为，这可以对从病理(如癌症生长和转移)到有益(如组织工程和再生医学)的理解过程产生积极影响。除了科学的社会影响，合作研究团队寻求通过双管齐下的方法增加STEM中代表性不足的学生的参与。首先，将在高中课堂上引入基于问题的学习，让经济困难的学生接触到研究项目，并有望激发他们对STEM的兴趣。其次，利用圣地亚哥州立大学作为少数群体服务机构的角色和加州大学圣地亚哥分校作为一所排名较高的研究型大学的背景，本科生将通过多机构教学和研究计划接受尖端、计算和实验机械生物学技术方面的培训。我们已经建立了两个研究目标，以解决在2D和3D环境中细胞粘附力调节力传递的不同假设。首先，肌球蛋白在肿瘤细胞定向2D迁移过程中的收缩能力将通过不稳定的焦点粘连进行研究。其次，将研究癌细胞在3D细胞外基质中的力敏机制，以探讨为什么强黏附细胞和弱黏附细胞在肿瘤细胞分裂和侵袭方面存在差异。为了研究这些目标，将使用微流控系统，根据粘附性分离特征良好的上皮性癌细胞株。将研究三种类型的内皮癌细胞(肺、前列腺和乳腺)，以确保力感应机制在不同类型的肿瘤中是一致的。牵引力显微镜将被用来研究分子和细胞水平的力学。细胞还将被功能阻断或功能增强抗体处理，这些抗体将分别减弱或增强粘附力。实验研究将与计算模型相结合，以清楚地阐明观察到的行为的潜在机制。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Cancer cells in solid tumors must detach, migrate, and invade surrounding tissues in order to metastasize. This process is regulated by properties of the extracellular matrix, including its stiffness and the its adhesion force with the tumor cells. But tumors are not homogeneous, and these tumor cells can respond differently to their environment. This project will investigate how changes in cellular adhesion properties affect the fate of cells and, in particular, whether they will migrate, proliferate, differentiate, or die -- all key parts of cellular behavior. This project will enhance fundamental understanding of how changes in cellular mechanical properties affect a broad range of cell behaviors. Once this knowledge is expanded, it can be used to influence cellular behavior at the tissue level, which can have a positive impact on understanding process that vary from the pathological (such as cancer growth and metastasis) to the beneficial (such as tissue engineering an regenerative medicine). In addition to the societal impact of the science, the collaborative research team seeks to increase the involvement of underrepresented students in STEM through a 2-pronged approach. First, problem-based learning will be introduced in high school classrooms to expose economically disadvantaged students to research projects and, hopefully, excite them about STEM. Second, leveraging San Diego State University's role as a minority-serving institution and UCSD's background as a highly ranked research university, undergraduate students will be trained in cutting edge, computational and experimental mechanobiology techniques through a multi-institutional instructional and research program.Two research objectives have been established to address the hypothesis that adhesion strength modulates force transduction differently for cells in 2D and 3D environments. First, myosin contractility during directed, 2D migration of tumor cells will be investigated through labile focal adhesions. Second, the force-sensing mechanisms of cancer cells in 3D extracellular matrix will be studied to investigate why there is a difference in tumor cell division and invasion between strongly and weakly adherent cells. In order to investigate these aims, a microfluidic system will be used that can separate well-characterized epithelial cancer cell lines by their adhesive properties. Three types of endothelial cancer cells will be investigated (lung, prostate, and mammary) to insure that the force-sensing mechanisms are consistent across the tumor types. Traction-force microscopy will be employed to study the molecular and cellular-level mechanics. Cells will also be treated with function-blocking or function-enhancing antibodies that will weaken or strengthen the adhesion strength, respectively. The experimental studies will be combined with computational modeling in order to clearly elucidate the underlying mechanisms of the observed behavior.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.