Twist expression in dentigerous cyst, odontogenic keratocyst, and ameloblastoma.

Epithelial-mesenchymal transition (EMT) is a process which is associated with a loss of intercellular adhesion, acquired mesenchymal shape, and increased motility by epithelial cells. Twist is one of the key regulators of EMT.In view of the distinct clinical behavior of odontogenic lesions, the objective of the present study was to investigate the immunohistochemical expression of Twist in these lesions. In this study, 70 formalin-fixed, paraffin-embedded tissue blocks of odontogenic lesion consisting of 16 unicystic ameloblastomas (UA), 17 solid ameloblastomas (SA), 18 odontogenic keratocysts (OKC), and 19 dentigerous cysts (DC) were reviewed using immunohistochemistry for Twist staining. In this study, Twist immunostaining was evident in all groups of the specimens except the dentigerous cyst group. Twist expression was seen in 58.8 % (10/17) of SA, 50 % (8/16) of UA, and 44.4 % (8/18) of OKCs. 23.5 % of SA, 18.8 % of UA, and 16.7 % of OKCs showed Twist expression in more than 50 % of cells. Statistical analysis showed that Twist expression levels were significantly higher in ameloblastomas (SA and UA) and OKCs than dentigerous cysts (P = 0.002). There were no significant differences between Twist expression in SAs, UAs, and OKCs (P > 0.05). The results of this study propose that the high expression rate of Twist plays a role in the pathogenesis of ameloblastomas and OKCs and might be one of the reasons for the aggressive behavior of ameloblastomas and high recurrence of OKCs and could reinforce the classification of OKC as an odontogenic tumor.