Scientists at the University of Sheffield have identified a protein which causes cells to eat their dying neighbours, helping to prevent inflammation – something which is vital in the fight to stop cancer spreading.
Researchers discovered the Pac-Man like Rac1 protein switches cell function and causes cells to respond to ‘eat me’ signals omitted from their dying neighbouring cells and clears them away efficiently to minimise damaging inflammation which is linked to a variety of diseases including cancer.
Rac1 Controls Both the Secretory Function of the Mammary Gland and Its Remodeling for Successive Gestations, Developmental Cell, 12 September 2016.
An important feature of the mammary gland is its ability to undergo repeated morphological changes during each reproductive cycle with profound tissue expansion in pregnancy and regression in involution. However, the mechanisms that determine the tissue’s cyclic regenerative capacity remain elusive.
Pac-Man like protein which eats dead cells could help in the fight against cancer, University of Sheffield, 09 September 2016.
We have now discovered that Cre-Lox ablation of Rac1 in mammary epithelia causes gross enlargement of the epithelial tree and defective alveolar regeneration in a second pregnancy. Architectural defects arise because loss of Rac1 disrupts clearance in involution following the first lactation.
We show that Rac1 is crucial for mammary alveolar epithelia to switch from secretion to a phagocytic mode and rapidly remove dying neighbors. Moreover, Rac1 restricts the extrusion of dying cells into the lumen, thus promoting their eradication by live phagocytic neighbors while within the epithelium. Without Rac1, residual milk and cell corpses flood the ductal network, causing gross dilation, chronic inflammation, and defective future regeneration.