title: Immunohistochemical expression of Rho GTPases in ameloblastomas.
abstract: Rho GTPases are proteins that regulate cell cycle, shape, polarization, invasion, migration, and apoptosis, which are important characteristics of normal and neoplastic cells. Rho GTPases expression has been reported in normal tooth germ and several pathologies; however, it has not been evaluated in ameloblastomas. The aim of this study was to analyze the expression and distribution of RhoA, RhoB, Rac1, and Cdc42 Rho GTPases in solid and unicystic ameloblastomas. Three-micrometer sections from paraffin-embedded specimens were evaluated by using an avidin-biotin immunohistochemical method with antibodies against the proteins mentioned above. RhoA and RhoB staining was observed in a high number of cells (P < 0.05) and greater intensity in non-polarized ones. Rac1 was not observed, and Cdc42 did not show any statistical differences between the number of non-polarized and basal positive cells (P > 0.05). Upon comparing the studied ameloblastomas, a higher number of positive cells in the unicystic variant was observed than that in the solid one (P < 0,05). The results obtained suggest that these GTPases could play a role in the ameloblastoma neoplastic epithelial cell phenotype determination (polarized or non-polarized), as well as in variant (solid or unicystic) and subtype (follicular or plexiform) determination. Furthermore, they could participate in solid ameloblastoma invasion mechanisms.
authors.affiliation: Pathology Department, Federal University of Santa Catarina, Florianopolis, SC, Brazil. modolo@ccs.ufsc.br
authors.forename: Filipe
authors.initials: F
authors.lastname: Modolo
authors.forename: Michelle Tillmann
authors.initials: MT
authors.lastname: Biz
authors.forename: Suzana Machado
authors.initials: SM
authors.lastname: de Sousa
authors.forename: Rodolfo de Lima
authors.initials: Rde L
authors.lastname: Fachinelli
authors.forename: Virgínia Oliveira
authors.initials: VO
authors.lastname: Crema
mesh_terms: D000564:Ameloblastoma / Q000201:enzymology* / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry; D007573:Jaw Neoplasms / Q000201:enzymology* / Q000473:pathology; D014018:Tissue Distribution; D020764:cdc42 GTP-Binding Protein / Q000378:metabolism; D020830:rac1 GTP-Binding Protein / Q000378:metabolism; D020741:rho GTP-Binding Proteins / Q000378:metabolism*; D020742:rhoA GTP-Binding Protein / Q000378:metabolism; D020743:rhoB GTP-Binding Protein / Q000378:metabolism
chemical_list: D020764:cdc42 GTP-Binding Protein; D020830:rac1 GTP-Binding Protein; D020741:rho GTP-Binding Proteins; D020742:rhoA GTP-Binding Protein; D020743:rhoB GTP-Binding Protein