Probing mechanical properties to study cancer cell migration

T Technology (General)

Chim, Ya Hua ; Engineering & Physical Sciences Research Council (EPSRC) ; Yin, Huabing

University:University of Glasgow

Department:School of Engineering

关键词: cell mechanics, cell migration, ROCK pathway, AFM, microfluidics.;   

Others  :  http://theses.gla.ac.uk/7901/1/2016chimphd.pdf

来源: University of Glasgow

【 摘 要 】

To best comprehend cellular behaviour and how it determines cell migration in metastatic cancer, the research described here has focused on cell mechanics. The signalling pathway involving Rho-associated kinase (ROCK) has emerged as being the main regulator for the cellular cytoskeleton and actomyosin contractility that play key roles in metastatic cancer formation. In this thesis, an examination is made of how the cellular properties intertwine as ROCK is overexpressed. In research towards being able to measure and describe the viscoelastic properties of a cell that are associated with cell mechanics, over a wide range of timescales, a novel AFM force indentation data analysis method was applied.In particular, as part of this study, pancreatic ductal adenocarcinoma (PDAC) cells were overexpressed with ROCK, and the influence of ROCK activity on cell’s elastic and viscoelastic properties were quantified. It was found that when ROCK activity was overexpressed in cells, their elasticity decreased while their viscosity remained unchanged. These properties had a direct correlation with the activity of ADF/cofilin - the proteins downstream of ROCK. This meant that with overexpression, more stable actin bundles were present along with their inward stresses generated by the actomyosin contraction. This is consistent with an increased level of compressive forces within cells. Collective compressive forces between cell-cell are associated with the packing of cells that decreases cellular response.To further understand the role of ROCK activity in cancer invasion, a microfluidic device was created to mimic cell migration through tissue. The device consists of precisely defined microchannels with dimensions chosen to hinder and confine the cells in a manner similar to that found in a physiological environment. It was found that overexpressed ROCK1 cells in the confinement had notable decrease in cell size and motility. Along with this decrease in mechanical properties, observations also gave rise to questions about the connection between these properties that remain to be answered.