Evaluation of Phosphatase and Tensin (PTEN) Homolog Immunoexpression in Normal Oral Mucosa, Epithelial Dysplasia and Oral Squamous Cell Carcinoma

BACKGROUND: Phosphatase and Tensin Homolog (PTEN) is a tumor suppressor gene located on chromosome 10q23. PTEN plays a major role in cell cycle arrest, programming apoptosis, regulation of cell adhesion, migration and differentiation. Loss of heterozygosity and mutations of PTEN have been detected in many human cancers. Studies have shown that loss of PTEN expression in oral squamous cell carcinoma and in potentially malignant disorders. OBJECTIVE: To evaluate and correlate the expression of Phosphatase and Tensin (PTEN) homolog marker in normal oral mucosa, oral epithelial dysplasia and oral squamous cell carcinoma by immunohistochemistry. METHODS: Immunohistochemical expression of Phosphatase and Tensin Homolog (PTEN) was analyzed in formalin fixed paraffin embedded blocks of hisopathologically confirmed cases of normal oral mucosa (n=10), oral epithelial dysplasia (n=10) and oral squamous cell carcinoma (n=30). RESULTS: There was statistically significant loss of PTEN expression seen in oral epithelial dysplasia and oral squamous cell carcinoma when compared to that in normal oral mucosa based on the intensity of staining as well as positive and negative staining. INTERPRETATION AND CONCLUSION: The results suggested that immunohistochemical expression of PTEN was reduced in dysplasia and in oral squamous cell carcinoma when compared to that in normal oral mucosa.