Tp63 in oral development, neoplasia, and autoimmunity

The Tp63 gene encodes for multiple isoforms of the p63 transcription factor, a member of the p53 family of proteins. Much like its more famous sibling, the biological role of p63 is quite complex, with wide-ranging effects on development, differentiation, and cellular lineage choices. The crucial function of p63 is epitomized by the striking phenotype of p63 knockout mice. These animals have a profound block in the development of stratified epithelia and aplasia of multiple ectodermal appendages, as well as orofacial clefting and limb defects. Remarkably, a similar spectrum of phenotypic alterations is observed in human syndromes resulting from Tp63 gene mutations. p63 is an important hub in the transcriptional and signaling networks of epithelial cells; thus, it is not surprising that dysregulation of this transcription factor is associated with squamous cell carcinoma. Finally, as a testament to the growing repertoire of p63-associated diseases, autoantibodies to p63 are associated with chronic ulcerative stomatitis, an oral immunologically mediated disease. Over the past decade, our understanding of the broad biologic and pathophysiological roles of p63 has grown significantly. In this review, we discuss the molecular attributes of Tp63 and the clinical consequences of Tp63 dysregulation, particularly as it pertains to oral tissues.