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.

Introduction:Angiogenesis is a complex event mediated by angiogenic factors released from cancer cells and immune cells. It has been reported to be associated with progression, aggressiveness and metastases of various malignant tumors including oral squamous cell carcinoma (OSCC). Similarly, mast cells have also been reported to play a role in tumor progression and metastases by promoting angiogenesis.Objectives:The present study was conducted to compare microvessel density (MVD) and mast cell density (MCD) in different histological grades of OSCC in comparison with normal oral mucosa (NM).Materials and Methods:Comparison of MVD by CD34 and MCD by toluidine blue among different histological grades of OSCC and in NM as controls.Statistical Analysis:The results were analysed using “t” test, ANOVA and Pearson's correlation co-efficient.Results:The mean MVD was higher in different grades as compared to normal mucosa. Intergroup comparison of increase in MVD between different grades of OSCC was not found to be highly statistically significant. Pearson's correlation between MVD and MCD revealed a linear increase in MVD as the MCD increased, suggestive of a positive correlation.Conclusion:There was significant correlation found between MVD and MCD which was in agreement that mast cells promote tumor progression through upregulation of angiogenesis.