p53 expression in odontogenic keratocyst epithelium

Area of Science:

• Oral Pathology
• Molecular Biology
• Oncology

Background:

• Odontogenic keratocysts (OKC) exhibit aggressive behavior.
• The role of p53 protein in OKC development is not fully understood.
• p53 protein expression can indicate cellular abnormalities.

Purpose of the Study:

• To investigate p53 protein expression in OKC, radicular cysts (RC), and dentigerous cysts (DC).
• To determine if p53 gene mutations correlate with p53 protein overexpression in OKC.
• To analyze the distribution and significance of p53 protein in different cyst types.

Main Methods:

• Immunohistochemistry using three distinct p53 antibodies (BP53-12, 1801, CM1) on paraffin-embedded cyst sections.
• Quantitative analysis of p53-positive cells using TV image analysis.
• Polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) and direct sequencing to detect p53 gene mutations in exons 5-10.

Main Results:

• Clone BP53-12 demonstrated consistent nuclear p53 staining in all cyst types, with significantly higher expression in OKC compared to RC and DC.
• p53-positive cells in OKC were predominantly suprabasal, differing from RC and DC.
• No p53 gene mutations were detected in exons 5-10 of OKC, RC, or normal oral mucosa samples.
• A significant correlation was observed between p53 and Ki67 labeling in OKC when NBCCS-related cysts were excluded.

Conclusions:

• Overexpression of p53 protein in OKC epithelium, detected via immunocytochemistry, is not linked to p53 gene mutations.
• The observed p53 protein overexpression likely results from stabilization or overproduction of the normal p53 protein.
• These findings contribute to understanding the molecular mechanisms underlying OKC pathogenesis.