Rapid Molecular and Morphological Responses of Prostate Cell Lines to Cell–Cell Contact

Abstract

Cell-cell adhesion in 2-D PZ-HPV-7 prostate epithelial and DU-145 prostate cancer cell aggregates (monolayers), synchronously and rapidly (within 30 s) formed in suspension in an ultrasound trap has been examined over 60 min. The intracellular distributions of the cadherin/catenin complex components for both cell lines were time-dependent and were clearly identifiable as early as 150 s following cell-cell contact in the trap, while equilibrium positions were reached within 60 min following cell-cell contact. The accumulation of E-cadherin at the cell-cell interface was greater for PZ-HPV-7 than for DU-145 cells over 60 min in the trap, with the apparent formation of adherens junctions over that time scale in PZ-HPV-7 but not in DU-145 cells. The amounts of F-actin, α-, β-, and γ -catenins recruited to the cell-cell interface of PZ-HPV-7 cells were on average 2.4 times higher than those of DU-145 cells. The ability of different cell types to spread along neighboring cells was 1.5-fold greater for the PZ-HPV-7 than for the DU-145 cells. These results, discussed also in the context of earlier studies of cell adhesion in an ultrasound trap, characterize a reduced adhesiveness of DU-145 cells compared to PZ-HPV-7 cells.

NCAM and PSA-NCAM dependent membrane spreading and F-actin reorganization in suspended adhering neural cells

“…We recognize that the NCAM dependence of membrane spreading shown here for the C6 neural cell line cannot be a general model for cell adhesion since cells that do not express NCAM (as for example the prostate epithelial cell line PZ-HPV-7) have exhibited a spreading capacity similar to that reported here for neural cells [33].…”

“…It is appreciated that the cell perimeters are longer than those for perfect circles as cells have surface area in excess of that required to contain a spherical cell volume (a property necessary so that when a cell divides the two resulting smaller volumes are each continuously covered by membrane) [33]. No geometrical allowance can therefore be made for the consequent departure from circular profiles as membrane spreading continues [33]. Within that limitation it will be taken, for a 'cell-cell contact chord' L and cell radius R (Supplementary Figure 1iii), that u .…”

“…The assembly is placed on the top of an epi-fluorescence microscope's stage. (iii) Schematic diagram of an interacting cell doublet; L is the length of the F-actin staining region or 'chord' (drawn here as a straight line), R is the radius of the cells and u is the angle subtended by the 'chord' at the centre of the cell [33].…”

“…is the angle subtended by the chord at the centre of the cell. While the membrane dynamics and micromechanics at the end of contact regions are not known it is reasonable to assume that, for cells, the ability to continue to increase the length of a chord depends, among other things, on both the surface density of the homophilic receptors and the local resistance of the membrane to deformation [33]. Measurements of the angle u of a cellcell interface 'chord' were performed using Cell-P software.…”

“…Estimates of the angle u subtended by the F-actin staining region at the centres of a pair of interacting cells were measured as previously described [33]. A detailed description and a Figure …”