Immunohistochemical expression of E-Cadherin and Cyclin D1 in different grades of oral squamous cell carcinoma.

Abstract

Oral squamous cell carcinoma (OSCC) is the most common oral malignancy, representing up to 80-90% of all malignant neoplasms of the oral cavity. It results from the multistep accumulation of heterogeneous genetic changes. Important risk factors for OSCC include the use of tobacco or betel quid chewing, alcohol consumption, human papillomavirus and poor nutrition. E-Cadherin as a tumour suppressor gene sets a threshold for Wnt/β-catenin signalling. When expression of E-Cadherin is lost, potentiation of Wnt signalling pathway occurs leading to loss of cell-cell adhesion. The cyclin D1 gene (CCND1) located on chromosome 11q13 encodes a nuclear protein that is the regulatory subunit of Cdk-4 and Cdk-6. Cyclin D1 plays a major role in cell cycle transition from G1 to S phase by contributing to inactivation of the retinoblastoma gene product, and overexpression of CCND1 has been reported in 35-40% cases of OSCC. Considering this, we decided to evaluate and compare the expression of CE-Cadherin and Cyclin D1 in different grades of OSCC. A retrospective study was carried out on 60 formalin-fixed paraffin embedded tissue blocks comprising of 20 cases of well-differentiated OSCC, 20 cases of moderately differentiated OSCC and 20 cases of poorly differentiated OSCC. Diagnosed (using H and E), with oral mucosa taken as control. There was downregulation of E-Cadherin and overexpression of Cyclin D1 in increasing grades of OSCC and the difference was statistically significant. E-Cadherin was localised to membranous and shifted to cytoplasm as the grade worsened. Cyclin D1 was localised to nuclei of cells and the expression was seen more at the peripheral portions of tumour islands depicting the proliferative activity of tumour front. The study revealed a good prognostic role of both E-Cadherin and Cyclin D1 in OSCC. The markers can be used for prognostic as well as therapeutic purposes.