title: Enhanced invasion of metastatic cancer cells via extracellular matrix interface.
abstract: Cancer cell invasion is a major component of metastasis and is responsible for extensive cell diffusion into and major destruction of tissues. Cells exhibit complex invasion modes, including a variety of collective behaviors. This phenomenon results in the structural heterogeneity of the extracellular matrix (ECM) in tissues. Here, we systematically investigated the environmental heterogeneity facilitating tumor cell invasion via a combination of in vitro cell migration experiments and computer simulations. Specifically, we constructed an ECM microenvironment in a microfabricated biochip and successfully created a three-dimensional (3D) funnel-like matrigel interface inside. Scanning electron microscopy demonstrated that the interface was at the interior defects of the nano-scale molecular anisotropic orientation and the localized structural density variations in the matrigel. Our results, particularly the correlation of the collective migration pattern with the geometric features of the funnel-like interface, indicate that this heterogeneous in vitro ECM structure strongly guides and promotes aggressive cell invasion in the rigid matrigel space. A cellular automaton model was proposed based on our experimental observations, and the associated quantitative analysis indicated that cell invasion was initiated and controlled by several mechanisms, including microenvironment heterogeneity, long-range cell-cell homotype and gradient-driven directional cellular migration. Our work shows the feasibility of constructing a complex and heterogeneous in vitro 3D ECM microenvironment that mimics the in vivo environment. Moreover, our results indicate that ECM heterogeneity is essential in controlling collective cell invasive behaviors and therefore determining metastasis efficiency.
authors.affiliation: Key Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, China.
authors.forename: Jiangrui
authors.initials: J
authors.lastname: Zhu
authors.affiliation: Department of Physics, Arizona State University, Tempe, Arizona, United States of America.
authors.forename: Long
authors.initials: L
authors.lastname: Liang
authors.affiliation: Department of Physics, Arizona State University, Tempe, Arizona, United States of America; Materials Science and Engineering, Arizona State University, Tempe, Arizona, United States of America.
authors.forename: Yang
authors.initials: Y
authors.lastname: Jiao
authors.affiliation: Key Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, China.
authors.forename: Liyu
authors.initials: L
authors.lastname: Liu
mesh_terms: D045744:Cell Line, Tumor; D002465:Cell Movement / Q000502:physiology*; D003094:Collagen / Q000378:metabolism; D004338:Drug Combinations; D005109:Extracellular Matrix / Q000378:metabolism* / Q000473:pathology*; D006801:Humans; D007797:Laminin / Q000378:metabolism; D009361:Neoplasm Invasiveness / Q000473:pathology*; D009362:Neoplasm Metastasis / Q000473:pathology*; D016609:Neoplasms, Second Primary / Q000378:metabolism / Q000473:pathology; D011509:Proteoglycans / Q000378:metabolism; D059016:Tumor Microenvironment / Q000502:physiology
chemical_list: D004338:Drug Combinations; D007797:Laminin; D011509:Proteoglycans; C059485:matrigel; D003094:Collagen