Extracellular matrix mechanics regulate cell signaling and migratory potential in cancer
The objective of the presented research is to examine the relationship between the cellular microenvironment and biochemical response of metastatic cells. Clinically recognized as a trait of cancer progression, the cellular microenvironment can have variable and distinct mechanical properties that are processed via cellular mechanosensing, resulting in a cellular biochemical response. A range of studies investigating the interactions between the cellular micromechanical environment and the cell's molecular response during disease progression have been made, yet remain absent of quantitative characterization of many of these coordinated responses. The fundamental inquiry that drives the following research attempts to elucidate how a cell perceives the physical microenvironment and converts that signal to a biochemical response. With the goal of providing insight to such responses, the presented research seeks to elucidate the following questions: (1) What are the integrated effects of ECM stiffness, ECM architecture, and breast cancer cell metastatic potential on cell migration? (2) How does endogenous tissue transglutaminase (tTG) cross-linking of the ECM scaffold effect ECM mechanical properties? (3) How does the architecture and stiffness of the extracellular matrix (ECM) effect the systems-level cellular migration and signaling response? (4) What are the integrated effects of ECM architecture and the targeted knockdown of integrin [beta]1 and MT1-MMP on cellular metastatic potential? The presented research utilizes an interdisciplinary approach, integrating experimental mechanics, biochemical analysis, cellular biology techniques, covalent chemistry, and various microscopy techniques, to investigate these events. In short, cancerous cells are cultured atop or within synthetic collagen type I ECMs of varying mechanical stiffness and structure. These cells are subsequently analyzed by molecular analysis and immunoassays, including quantitative PCR, Western blotting, and gelatin zymography, to acquire measures of the cellular response to perturbations of micromechanical environment. Time-lapse microscopy experiments and subsequent image analyses enable observations of cellular migratory potential through synthetic ECMs. Results indicate that cooperative synergy between ECM properties, cell-matrix adhesion, and pericellular proteolysis drive cell migratory potential of highly invasive tumorigenic cell populations. Collectively, these findings contribute to the cancer biology and mechanobiology fields by systematically extending current insights of matrix mechanics, cellular signaling, and cellular migratory potential in cancer.