For tumour cells to infiltrate new tissues, they must first clear an escape route from their primary site by remodelling their environment. Michael Olson of the Beatson Institute for Cancer Research in Glasgow, UK, and his colleagues have identified two proteins, LIMK1 and LIMK2, that are active in cells on a tumour's leading edge and seem to pave the way.

The LIMK proteins regulate actin, a key protein in the cellular skeleton. The researchers found that if these proteins were inhibited in cultured breast and skin cancer cells, the cells were still motile on a two-dimensional surface, but became less invasive in three-dimensional assays. Two processes normally associated with remodelling — degradation of nearby proteins and deformation of the matrix surrounding the cancer cells — were also impaired, suggesting that the cells failed to reshape their environment and forge a way out.

J. Cell Biol. doi:10.1083/jcb.201002041 (2010)