Aggregation kinetics of well and poorly differentiated human prostate cancer cells

Abstract

Aggregation of attachment-dependent animal cells represents a series of motility, collision, and adhesion events applicable to such diverse fields as tissue engineering, bioseparations, and drug testing. Aggregation of human prostate cancer cells in liquid-overlay culture was modeled using Smoluchowski's collision theory. Using well (LNCaP) and poorly differentiated (DU 145 and PC 3) cell lines, the biological relevance of the model was assessed by comparing aggregation rates with diffusive and adhesive properties. Diffusion coefficients ranged from 5 to 90 microm(2)/min for single LNCaP and PC 3 cells, respectively. Similar diffusivities were predicted by the persistent random walk model and Einstein relation, indicating random motion. LNCaP cells were the most adhesive in our study with reduced cell shedding, 100% adhesion probability, and enhanced expression of E-cadherin. There was an increase in DU 145 cells staining positive for E-cadherin from nearly 20% of single cells to uniform staining across the surface of all aggregates; under 30% of PC 3 aggregates stained positive. Aggregation rates were more consistent with adhesive properties than with motilities, suggesting that aggregation in our study was reaction-controlled. Relative to other assays employed here, aggregation rates were more sensitive to phenotypic differences in cell lines and described size-dependent changes in aggregation at a finer resolution. In particular, model results suggest similar aggregation rates for two-dimensional DU 145 and PC 3 aggregates and upwards of 4-fold higher rates for larger three-dimensional DU 145 spheroids, consistent with expression of E-cadherin. The kinetic model has application to spheroid production, to cell flocculation and as an adhesion assay.

Lateral assembly of N-cadherin drives tissue integrity by stabilizing adherens junctions

“…However, in another study comparing well-and poorly differentiated human prostate cancer cells, Enmon et al [18] have observed similar differences in the rates of spheroid formation. They found that the increased rate in spheroid formation was correlated with an increased expression level of E-cadherins.…”

Vesicle traffic through intercellular bridges in DU 145 human prostate cancer cells

“…This study suggests that filopodia have additional roles in culture. Liquid-overlay culture generates spheroids of cancer cells used for drug testing [14]. The cells preferentially attached to each other rather than to the attachment-limiting agar substrate.…”

“…Chambers were either pretreated with an attachment-limiting substrate, agar (liquid-overlay culture), or used without a coating (monolayer culture). For the former, the chambers were covered with a thin layer (1 mm) of 0.25% agar (Invitrogen, Carlsbad, CA) prepared in serum-free GTSF-2 medium [14]. The inoculum for these cultures consisted of 2.0 ×10 4 cells/cm 2 in 2 ml of complete GTSF-2.…”

Immunohistochemical analysis of differentiation in static and mixed prostate cancer spheroids

“…Liquid-overlay cultures were prepared by solidifying a mixture of 1% agar (Invitrogen, Carlsbad, CA) in 8-ml serum-free GTSF-2 medium within 100 mm × 20 mm petri dishes (Becton Dickinson Labware, Franklin Lakes, NJ) as described in Enmon et al [15]. The inoculum for these static cultures consisted of 1.7 × 10 5 cells/ml in 8-ml of complete GTSF-2.…”