Biological potential of a functional human SNAIL retrogene.

Snail genes encode zinc finger transcription factors required for the development of vertebrate and invertebrate embryos. They trigger epithelial to mesenchymal transitions (EMTs), thereby allowing epithelial cells to emigrate from their place of origin and form tissues such as the mesoderm and the neural crest. Snail genes are also involved in the EMTs responsible for the acquisition of invasiveness during tumor progression. This aspect of their activity is associated with their ability to directly repress E-cadherin transcription. Here we describe the existence of an active human Snail retrogene, inserted within an intron of a novel evolutionarily conserved gene and expressed in different human tissues and cell lines. Functional analyses in cell culture show that this retrogene maintains the potential to induce EMTs, conferring migratory and invasive properties to epithelial cells. In light of this data, we have renamed it SNAIL-like, a new player that must be considered in both physiological and pathological studies of SNAIL function in humans.