Ameloblastoma is an odontogenic
neoplasm characterized by local invasiveness and a tendency toward recurrence, whereas
adenomatoid odontogenic tumor (AOT) is an indolent
neoplasm. The objective of the present study was to immunohistochemically analyze the role of alpha2beta1, alpha3beta1, and alpha5beta1
integrins in the cellular events and cell-matrix interactions that occur in these
tumors and their consequent repercussions on the architectural arrangement and
biologic behavior of these lesions.
Paraffin-embedded specimens from 30
ameloblastomas (20 solid and 10 unicystic
tumors) and 12 AOTs were submitted to immunohistochemistry using the catalyzed signal amplification system. A difference in the pattern of
integrin expression was observed between the various histologic types of
ameloblastoma. No significant difference in labeling intensity was observed between unicystic and solid
ameloblastomas, but comparison between
ameloblastomas and AOT showed a significantly stronger expression of
alpha5beta1 integrin in the former (P < .05). Our findings suggest an important role of the
integrins studied in the architectural characteristics of
ameloblastomas and AOTs and a possible participation of
alpha5beta1 integrin in the mechanism of local invasion of
ameloblastomas.