SIX3 (F1I1S) Rabbit mAb #62173

Sine oculis homeobox (SIX) proteins belong to a family of evolutionarily conserved transcription factors discovered in Drosophila mutant screens for embryonic eye development genes (1-3). The prototypical family member (sine oculis, so) was named for eyeless embryos carrying mutations in a gene highly conserved among vertebrates, including humans (SIX1) (4). A total of six family members (SIX1-6) have been identified in vertebrates. Each SIX protein contains a homeobox nucleic acid recognition domain (HD) with a DNA-binding helix-turn-helix motif and an adjacent SIX domain, which may be involved in regulating protein-protein interactions (5). In addition to their critical functions during embryonic organogenesis, research studies suggest that SIX proteins play additional roles in postnatal cell cycle regulation, with potentially important implications in tumorigenesis (6,7). In addition to its well-established role within gene networks regulating neural patterning and brain development (8,9), SIX3 was more recently reported to regulate postnatal pancreatic β cell maturation, in part by suppressing the expression of genes associate with fetal β cells and various non-β cell types (10,11). Dysregulated expression of SIX3 has also been linked with tumor development. For example, in a study of cell free DNA isolated from plasma, SIX3 was identified as a differentially methylated gene that was diagnostically relevant for patients with pancreatic ductal adenocarcinoma (12). This finding was consistent with earlier reports supporting a role for SIX3 as a tumor suppressor (13-15).