Epithelial to mesenchymal transition in drug-induced gingival overgrowth :

PLEASE NOTE: This work is protected by copyright. Downloading is restricted to the BU community: please click Download and log in with a valid BU account to access. If you are the author of this work and would like to make it publicly available, please contact open-help@bu.edu.Thesis (MSD) --Boston University, Henry M Goldman School of Dental Medicine, 2012 (Department of Periodontology and Oral Biology).Includes bibliographic references: leaves 39-46.Introduction: Gingival overgrowth (GO) is mainly considered as an adverse reaction to medications most notably phenytoin, nifedipine, and cyclosporine-A. Variable degrees of inflammation and fibrosis appear histologically in GO tissue samples. Epithelial to mesenchymal transition (EMT) is the process by which epithelial cells trans-differentiate into motile fibroblast-like cells. Most recently, EMT has been implicated in drug induced gingival overgrowth. We sought to evaluate whether increased degradation of the basement membrane and invasion of the underlying stroma by epithelial cells could be observed in human gingival overgrowth tissues. Methods: Tissues from twenty different human drug induced gingival overgrowth subjects (phenytoin n=6; cyclosporine-A, n=6; nifedipine, n=8), and fifteen non-overgrowth samples were evaluated by histological analyses, and by immunohistochemistry assays of key basement membrane proteins. Three to five serial sections from each subject were evaluated at five different locations per section. Under high power magnification (1000x), lengths of basal lamina were measured using a computerized ruler and numbers of disruptions of the basal lamina were counted. The degree of inflammation was also measured using the number of inflammatory cells per unit area. Finally, collagen IV and laminin-5 immunohistochemical staining was performed. [TRUNCATED