Expression of the proteins cyclin B1, Rb1, P27, BMP4 and LCA in pyogenic granuloma, peripheral ossifying fibroma and pyogenic granuloma with calcification

Abstract

It was performed an expression analysis of the proteins cyclin B1, Rb1(Retinoblaston Gen 1), P27( Protein 27), BMP4 (Bone Morpho- genetic Protein 4) and LCA (Leu- cocitary Commun Antigen), by the doublestain immunohistochemical method, in 24 cases of proliferative gingival lesions divided into three groups, according to their histopa- thological features: Group I (pyoge- nic granuloma), Group II (periphe- ral ossifying fibroma) and Group III (pyogenic granuloma with calcifica- tion) in consonance with the inclu- sion criteria of this study. LCA was employed as first primary antibody in all specimens. The genes cyclin B1, P27 and Rb have a critical role in the regulation of the transition in phases of cellular cycle, which are often altered in various neoplasic entities. Thus, the aim of this stu- dy was to compare the expression of such proteins among three lesions, in order to provide information on the proliferative activity of cells present in the tissue. The antibody anti-BMP4 was employed with the aim of assessing and comparing its expression in the stroma of lesions which produce mineralized mate- rial. Results showed similarity in relation to the expression of the proteins cyclin B1, Rb1, P27 and LCA, in the lesions of Groups I and III, and distinct expression in rela- tion to lesions of Group II. The ex- pression of the protein BMP4 in the lesions of Group II and III suggests different origins for the mineralized material of such lesions. The ne- gative expression of protein BMP4 in lesions of Group I confirms the absence of osteoprogenitor cells in their stroma. Key words: pyogenic granuloma, peripheral ossifying fibroma, cyclin B1, Rb1, P27, BMP4, LCA.