PROTOONCOGENE EXPRESSION IN OSTEOGENESIS INDUCED BY BONE MORPHOGENETIC PROTEIN

In this study, changes in the expression of protooncogenes c-fos and c -myc messenger ribonucleic acid were investigated in mice after implan tation of bone morphogenetic protein, The expression of c-fos showed a biphasic pattern, The first increase was observed on Day 1 with the a ggregation of round cells, The second increase was observed on Day 7 w ith the appearance of chondroblasts, The amount of c-myc messenger rib onucleic acid showed the sustained high levels from Days 2 to 7, Durin g this period, the proliferation of mesenchymal cells was histological ly evident, After Day 11, the expression of c-fos and c-myc decreased and remained at low levels despite the progress in chondroosteogenesis , The protooncogenes c-fos and c-myc appear to increase before calcifi cation in the process of bone morphogenetic protein induced bone and c artilage development.