Immunohistochemical localization of fibroblast growth factors FGF-1 and FGF-2, and receptors FGFR2 and FGFR3 in the epithelium of human odontogenic cysts and tumors

Acidic (FGF-1) and basic (FGF-2) fibroblast growth factors are members of a family of growth factors that function in growth, differentiation and rege neration of a variety of tissues. Their presence in human odontogenic cysts and tumors has not been previously investigated. This study was designed t o detect immunohistochemically the presence of these factors and two fibrob last growth factor receptors (FGFR2 and FGFR3) in a cross section of odonto genic cysts and tumors, to determine if they may be involved in the differe ntiation of odontogenic epithelium or, more specifically, in the developmen t of particular cysts or tumors. Archival formalin fixed paraffin-embedded tissues were used. With some exceptions, FGF-2 and the receptor FGFR2, were found in the cytoplasm and occasionally in the nuclei of cells of odontoge nic epithelium, while FGF-1 and the receptor FGFR3, were absent or only foc ally or weakly detected, using standard immunohistochemical techniques. The data are similar to those published for normal murine odontogenesis, sugge sting that these factors are associated with odontogenic differentiation ra ther than pathogenesis. The presence of significant nuclear staining in odo ntogenic epithelium associated with embryonic mesenchyme in ameloblastic fi bromas and ameloblastic fibro-odontomas suggests that FGF-2 may be involved in directing nuclear activity at the histodifferentiation stage of odontog enesis.