Immunohistochemical study on the pathogenesis of drug-induced gingival hyperplasia

Immunohistochemical localization of TGFβ, bFGF and their receptors, c-myc and bcl-2 oncoproteins, and Ki-67 antigen was examined in 9 hyperplastic gingival tissues induced by nifedipine and phenytoin, and 5 non-hyperplastic control tissues to elucidate the pathogenesis of drug-induced gingival hyperplasia. The results of our present study indicate that the overexpression of TGFβ, bFGF is related to the morphogenesis of hyperplastic lamina propria, whereas the intensive immunolocalization of c-myc and bcl-2 oncoprotein contributes to that of hyperplastic gingival epithelia. The tissue growth features of hyperplastic gingivae which were shown by Ki-67 antigen expression seem to reflect the involvement of these ligands in the pathogenesis of drug-induced gingival hyperplasia.