Immunohistochemical expression of Twist, E-cadherin and N-cadherin in ameloblastoma

Background: Ameloblastoma is a benign, locally invasive odontogenic neoplasm with a high rate of recurrence, and as these cells organize for migration they should go through epithelial-mesenchymal transition (EMT). The relative change during EMT can be quantified by E-cadherin to N-cadherin ratio. Objective: We investigate the expression and relative distribution of twist, E-cadherin/N-cadherin in ameloblastoma. Methods: Forty-six ameloblastoma formalin-fixed paraffin embedded blocks were cut into 5μm sections and immunostained for Anti-Twist, Anti-E-Cadherin and Anti-N-Cadherin antibody. Cytoplasmic/membrane staining was taken as positive for E-Cadherin and N-Cadherin while nuclear/cytoplasmic brown staining was positive for Twist. Result: Forty-six cases of ameloblastoma were studied. Twist, N-cadherin and E-cadherin staining were localized in ameloblast-like cells and stellate reticulum-like cells. For stellate reticulum cells, 16 (34.8%) cases expressed strong N-cadherin as against 8 (17.4%) cases that expressed strong E-cadherin. Ameloblastic carcinoma displayed EMT in ameloblasts in 50% of cases and cadherin switching was not seen here, however the stellate reticulum-like cells displayed EMT in 25% of cases and active cadherin switching in 50% of cases. Conclusion: Twist is expressed in ameloblastoma but the ratio of N to E-cadherin in these areas suggests stellate reticulum has higher metastatic potential. Although there are other mediators of EMT, in this study, EMT was recognized as completed only when E-cadherin was negative in both ameloblast and stellate reticulum-like cells while twist and N-cadherin were positive.