Par6 family proteins in cancer

The regulatory networks of cell polarization and polarity effector proteins have been subjects of feverish interest in the field of cell and developmental biology but many advances in the polarity research may have flown unnoticed past the radar of mainstream cancer biologist. However, recent findings suggesting important cell cycle gatekeeping functions for polarity proteins may change that. For example, PAR6 proteins interact with classical cancer driver signaling pathways, including MAPK and PI3K and moreover, PAR6 (PARD6) genes are frequently altered in various cancers. Mammalian genomes harbor three different PARD6 genes. Recent studies in breast cancer have suggested that different PARD6 genes are not only important players but may play even opposite roles during tumorigenesis.