Kinase

Cell biology

GTPase

Biology

PAK1

RAC1

Cell migration

Signal transduction

Focal adhesion

Cancer research

Biochemistry

Genetics

Actin cytoskeleton

CDC42

Cytoskeleton

Cell

Invadopodia

Cancer

Cancer cell

Frontiers in Cell and Developmental Biology

As key regulators of cytoskeletal dynamics, Rho GTPases coordinate a wide range of cellular processes, including cell polarity, cell migration and cell cycle progression. The adoption of a pro-migratory phenotype enables cancer cells to invade the stroma surrounding the primary tumour and move towards and enter blood or lymphatic vessels. Targeting these early events could reduce the progression to metastatic disease, the leading cause of cancer-related deaths. Rho GTPases play a key role in the formation of dynamic actin-rich membrane protrusions and the turnover of cell-cell and cell-extracellular matrix adhesions required for efficient cancer cell invasion. Here, we discuss the roles of Rho GTPases in cancer, their validation as therapeutic targets and the challenges of developing clinically viable Rho GTPase inhibitors. We review other therapeutic targets in the wider Rho GTPase signalling network and focus on the four best characterised effector families: p21-activated kinases (PAKs), Rho-associated protein kinases (ROCKs), atypical protein kinase Cs (aPKCs) and myotonic dystrophy kinase-related Cdc42-binding kinases (MRCKs).

Targeting Rho GTPase Signaling Networks in Cancer