Expression of p63 and Proliferating Cell Nuclear Antigen in Oral Submucous Fibrosis

Abstract

Aim: Oral squamous cell carcinoma (OSCC) may be preceded by potentially malignant disorders such as oral submucous fibrosis (OSMF). p63 can detect genetic changes in OSMF and it facilitates early detection of malignant transformation, whereas proliferating cell nuclear antigen (PCNA) is a marker of proliferation and may prove to be a useful objective indicator of the biological behavior of various tumors. The aim of this study was to investigate the expression and pattern of the intensity of p63 protein and PCNA in normal oral mucosa and OSMF using immunohistochemistry (IHC) and to correlate the expression of these biomarkers. Materials and Methods: A total of 15 archival paraffin-embedded blocks obtained from our department, which were histopathologically diagnosed early OSMF (n = 4), intermediate OSMF (n = 4), and advanced OSMF (n = 2) and normal mucosa (n = 5), were taken as the standard for comparison. p63 and PCNA positivity was analyzed using Kruskall-Wallis test followed by pairwise comparison using Mann-Whitney U test. The pattern of staining and intensity was compared using Chi-Square test for which Statistical Package for the Social Sciences (SPSS, v 22.0, IBM Corporation, Armonk, New York) was used. Results: All samples showed positive staining for p63 and PCNA. A statistically significant difference (P < 0.05) was seen between the frequency of occurrence of p63 and the PCNA pattern of expression among all the groups. The intensity of staining was mild to intense in the basal layer, as there was a progression toward the severity of the disease. Almost 75.4% correlation existed between p63 and PCNA, with high correlation and marked relationship. Conclusions: The OSMF is considered a potentially malignant disorder that has the potential to get transformed into OSCC. The malignant transformation is often associated with changes at the genetic level, and these are reflected by the altered expression of proteins. Our results showed that biomarkers such as p63 and PCNA are significant in predicting the malignant transformation in OSMF, so in future they may serve as a prognostic tool in the early detection of malignancies.