Immunohistochemical expression of phosphatase and tensin homolog in histologic gradings of oral squamous cell carcinoma

CONTEXT: Phosphatase and tensin homolog (PTEN) is a tumor suppressor gene located on chromosome 10q23. PTEN has its major function in the regulation of cell adhesion, cell cycle arrest, migration, apoptosis programming, and differentiation. This genomic region suffers loss of heterozygosity in many human cancers. AIMS: The aim of this study was to compare the immunohistochemical expression of PTEN in normal oral mucosa and oral squamous cell carcinoma (OSCC) and to correlate the PTEN expression in gradings of OSCC. MATERIALS AND METHODS: Thirty cases of paraffin tissue sections of previously diagnosed OSCC were taken. Of thirty cases, ten were well differentiated, ten were moderately differentiated, and ten were poorly differentiated. As a control, ten paraffin sections of oral normal mucosa tissue specimens were taken from patients undergoing extractions. The sections were stained for immunohistochemical expression of PTEN. The cells stained by PTEN antibody were counted, and an immunohistochemical score was obtained. STATISTICAL ANALYSIS USED: Statistical analysis was done using Mann-Whitney's test and Kruskal-Wallis test. RESULTS: Statistical analysis revealed that there was a significant difference between normal mucosa and OSCC in immunohistochemistry staining. However, there was no significant difference in PTEN expression among gradings of OSCC. CONCLUSIONS: The study concluded that there was a decrease in PTEN expression in OSCC than normal mucosa. It also concluded that PTEN is a tumor suppressor gene which has a wide role in oral carcinogenesis.