p63 – The Master Key to Epithelial Biology

Abstract

p63 gene is a key regulator of cell differentiation as well as cell proliferation in epithelial cells. It is involved in multiple functions in stratified squamous epithelium. It is seen to be overexpressed in more than 80% of the epithelial tumours. p63 is involved in regulating a number of critical processes including development, stem cell properties, tumourigenesis, apoptosis and senescence. Functions of p63 are not only varied, but also show antagonistic roles with respect to the isoforms. Its 2 isoforms, TAp63 and ΔNp63 have complex multi-dimensional functions. TAp63 acts purely as a tumor suppressor gene similar to p53, while ΔNp63 has major oncogenic functions. Newer studies are elucidating the role of p63 in a more clear light. Deciphering the multiple facets of p63 in its entirety could be the key to developing tailormade molecular therapies in epithelial malignancies. This review article is an effort to present a holistic view of p63, its isoforms and its varied interactions with other genes.