Apicobasal polarity

Overexpression of isoform δ of phosphoinositide 3-kinase (PI3Kδ) promotes stemness in hepatocellular carcinoma cell lines and mouse liver, whereas its inhibition promotes EMT, suggesting a key role for PI3Kδ in epithelial plasticity.

Apical–basal polarity is essential for epithelial cell form and function. Elucidating how distinct apical and basolateral compartments are established and maintained is essential to better understand the roles of apical–basal cell polarization in morphogenesis and how defects in polarity contribute to diseases such as cancer.

The early embryo maintains its structure in the face of large mechanical stresses during morphogenesis. Here they show that ASPP2 acts to preserve epithelial integrity in regions of high apical tension during early development.

The polarity of gastrointestinal organoids is reversed to study epithelial biology and host–microbe interactions. Access to the apical surface of the epithelium is increased while preserving epithelial integrity and secretory and absorptive functions.

Epithelial cells that organise into structures that contain a lumen are polarised. Here, the authors show that the short intracellular domain of transmembrane protein CD13 is required to capture endosomes at the apical site and is required for the polarisation of cells.