Fearful symmetry: subversion of asymmetric division in cancer development and progression.

Asymmetric division is an evolutionarily conserved process that generates daughter cells with different fates through the unequal partitioning of fate determinants. While asymmetric division is critically important in generating diversity during development, its dysregulation can also promote oncogenesis. In particular, signals that shift the normal balance of symmetric and asymmetric division can lead to a differentiation arrest and trigger cancer progression. Here, we discuss the studies that have provided increasing support for this idea. Beginning with original work carried out in Drosophila, we trace more recent work in mammalian systems that suggest that the subversion of asymmetric division can contribute significantly to the development and progression of both hematologic malignancies and solid cancers.