Cell to cell interactions play an important role in the development and maintenance of the beta cell phenotype. Here, we have investigated whether E-cadherin plays a role in regulating the growth of insulin-secreting MIN6 cells configured as three-dimensional islet-like clusters (pseudoislets). Pseudoislets form by cell aggregation rather than by proliferation from individual cells, and attain the size of primary mouse islets after approximately 7-days maintenance in culture. E-cadherin is known to mediate homotypic cell adhesion between beta cells and has also been implicated in a number of cellular processes, including proliferation, apoptosis and differentiation. E-cadherin and its associated intracellular elements, - and -catenin, were up-regulated in MIN6 pseudoislets. Pseudoislet formation was associated with an increased expression of cyclin-dependent kinase inhibitors and a concomitant down-regulation of Ki67, suggesting an overall reduction in cellular proliferation. However, measurements of 5-bromo-2'-deoxyuridine incorporation revealed that there were no differences in the rate of MIN6 cell proliferation whether they were configured as monolayers or as pseudoislets, which is likely to be a result of their being a transformed cell line. Cells within pseudoislets were not necrotic, but apoptosis appeared to be up-regulated in the islet-like structures. However, no differential expression of Fas and FasL was detected in monolayers and pseudoislets. These results suggest that cell to cell interactions within islet-like structures may initiate anti-proliferative and pro-apoptotic signals.