p63 expression in human tumors and normal tissues: a tissue microarray study on 10,200 tumors

Area of Science:

• Oncology
• Molecular Biology
• Cancer Research

Background:

• Tumor protein 63 (p63) is a transcription factor crucial for differentiation in tissues like squamous epithelium.
• p63 immunohistochemistry is widely used in tumor classification, but existing data on its cancer expression is inconsistent.

Purpose of the Study:

• To systematically analyze and map the expression patterns of p63 across a wide range of human tumors and normal tissues.
• To evaluate the diagnostic utility of p63 immunohistochemistry and its potential as a prognostic marker in various cancers.

Main Methods:

• Utilized tissue microarrays (TMAs) encompassing 12,620 samples from 115 tumor types and 76 normal tissue types.
• Conducted comprehensive p63 immunohistochemical analysis to catalogue expression levels and patterns.

Main Results:

• p63 expression was observed in normal tissues like squamous epithelium and urothelium.
• High p63 positivity was frequent in squamous cell carcinomas (96-100%), thymic tumors (100%), urothelial carcinomas (81-100%), basal cell carcinomas (100%), and salivary gland tumors (81-100%).
• Loss of p63 in urothelial carcinomas correlated with advanced stage, high grade, and poor survival, suggesting dedifferentiation. Aberrant p63 expression in gastric cancer was linked to lymph node metastasis.

Conclusions:

• p63 immunohistochemistry is a reliable diagnostic tool due to its high prevalence in specific tumor types.
• Loss of p63 expression can serve as a potential indicator of aggressive cancer phenotypes and clinical outcomes.