Poster

Glass transition in model cellular systems for the understanding cancer cell

Kiwamu Yoshii¹, Nen Saito², Kunimasa Miyazaki¹, Takeshi Kawasaki¹

Contact:  | Website

Heterogeneous cell migration plays an important physiological role in both healthy and inflammatory cellular systems[1,2]. This behavior is similar to the dynamic heterogeneity generally observed in glassy systems, so glassy behavior in cellular systems has been of great interest to many researchers. Notably, heterogeneous cell migration is observed in the actual cancer cells, and the larger the activated area of this heterogeneous cell migration, the higher the likelihood of future cancer metastasis. Therefore, it is crucial to elucidate the relationship between the dynamic heterogeneity of cancer cells and metastasis.
In many previous studies of cellular systems with the physical model, the vertex model[3] and Voronoi model [4], which divide the whole space and consider each of the divided regions as a cell, have been adopted. However, in such models, the cell shape is approximated by a polygon and the system density is fixed at 1. Therefore, it is not possible to consider the effects of particle density and free volume, which are important parameters in the glass transition. In this study, we introduce a deformable particle model expressed using the Fourier series[5] and clarify the effects of density, voids, stiffness, and deformability of the cellular particles on the glassy behavior.
First, we investigated the glassy behavior of a passive system where the particles have no self-propulsion. We mainly focus on the sensitivity of the dynamics to changes in the packing fraction, known as fragility, for varying particle deformability and stiffness. As a result, we find that the stiffer the particles, the more sensitively the viscosity tends to change. This trend is qualitatively consistent with experimental results of microgel particles[6]. On the other hand, in the active system where the particles have self-propulsion, we observed the opposite trend in the relationship between particle stiffness and fragility. This change in fragility behavior due to the introduction of activity is likely related to the heterogeneous migration of cellular particles. In my presentation, I will also discuss the relationship between heterogeneous migration and fragility.