What is the function of p63?

The p63 protein functions as a transcription factor, which means it attaches (binds) to certain regions of DNA and controls the activity of particular genes. The p63 protein interacts with other proteins to turn many different genes on and off at different times.

Is p63 a tumor suppressor?

p63 Expression in Cancer Mutations of p63 are extremely rare in human cancers, indicating it is not a canonical tumor suppressor.

What does a positive p63 mean?

P63: scored positive when high intensity staining was present on ≥50% of tumor cells; the remainder was scored negative [10]. TTF-1: scored positive when staining was present on ≥5% of tumor cells; the remainder was scored negative [11].

What is the role of p63 in epithelial cell differentiation?

The p53-related gene p63 is required for epithelial cell establishment and its expression is often altered in tumor cells. Great strides have been made in understanding the pathways and mechanisms that regulate p63 levels, such as the Wnt, Hedgehog, Notch, and EGFR pathways.

What regulates p63 levels?

Great strides have been made in understanding the pathways and mechanisms that regulate p63 levels, such as the Wnt, Hedgehog, Notch, and EGFR pathways. We discuss here the multiple signaling pathways that control p63 expression as well as transcription factors and post-transcriptional mechanisms that regulate p63 levels.

Is p63 directly regulated by the Wnt pathway?

Chromatin immunoprecipitation and reporter genes suggested that p63 is directly regulated by the Wnt pathway through binding of Lef1/Tcf with β-catenin to a region between the TA and ΔNp63 promoters ( 82 ), although another report identified a β-catenin responsive site within the proximal ΔNp63 promoter ( 83 ).

What is the role of p63 in UV-damaged cells?

The reduction of ΔNp63 augmented activation of p53 target genes and may contribute to cell death in UV-damaged cells. NF-κB repression of p63 may also have a role in epithelial cell differentiation, as overexpression of the NF-κB factor p65 in epithelial cells led to p63 downregulation and increased EMT ( 103 ).