Cytoskeleton Dynamics: Actin in Cell Invasion

Abstract

Basement membrane (BM) is a dense sheet of specialised extracellular matrix that separates epithelial layers of cells from the underlying tissue. The penetration of cells through BM barriers, called ‘invasion’, is an important process during normal tissue development and in cancer metastasis. To enable invasion, the cell adopts different shapes and creates different protrusive structures powered mainly by actin cytoskeleton dynamics. However, the exact cytoskeletal strategy that the cell uses to cross the physical BM barrier depends on the physiological context and the physical environment, as observed by examining actin structures in invading cancer and immune cells, and in cells that invade during developmental processes such as angiogenesis and anchor cell invasion in Caenorhabditis elegans . Key Concepts Actin polymerisation and actomyosin contraction can generate cell shape changes such as protrusions. Different actin‐binding proteins produce protrusions of different architecture and function. Shape changes and protrusions are necessary for cell invasion across basement membrane barriers. Cell invasion is observed in pathological and normal developmental contexts. The actin dynamics strategy employed by an invading cell depends on the environment and the physiological context.