A non-apoptotic cell death process, entosis, that occurs by cell-in-cell invasion.

TLDR: In this paper, the authors describe a non-apoptotic cell death program in matrix-detached cells, termed entosis, that is initiated by a previously unrecognized and unusual process involving the invasion of one cell into another, leading to a transient state in which a live cell is contained within a neighboring host cell.

Abstract: 1560 Epithelial cells require attachment to extra-cellular matrix (ECM) to suppress an apoptotic cell death program termed anoikis. We describe a non-apoptotic cell death program in matrix-detached cells, termed entosis, that is initiated by a previously unrecognized and unusual process involving the invasion of one cell into another, leading to a transient state in which a live cell is contained within a neighboring host cell. These 9cell-in-cell9 structures closely resemble similar cytological features in human cancers. Although a small percentage of live internalized cells can be released, the majority of internalized cells undergo non-apoptotic cell death by lysosomal acidification. Based on these data, we present evidence for a tumor suppressive role of entosis in human breast cancer. Paradoxically, we have also found that entosis can promote the development of aneuploidy, as live internalized cells can disrupt cytokinesis of host cells leading to multinucleation in vitro and in vivo. Thus, entosis may be tumor suppressive in some contexts and paradoxically tumor promoting in others. Models to investigate the role of entosis in human tumors will be presented.