[The expression of c-myc, c-fms, c-sis oncogenes in the trophoblast of normal pregnancy and trophoblastic disease].

Recently it has been suggested that proto-oncogene plays a role not only in cellular proliferation, development and differentiation, but also in neoplastic transformation. We now show the expression and its localization of c-myc, c-fms and c-sis proto-oncogenes in human developing chorionic tissue and fresh surgical specimens of mole and choriocarcinoma with the method of Northern blotting and In-situ hybridization. The 2.4kb c-myc transcript has been localized to the cytotrophoblast in early placenta and also localized to the C and S typed trophoblastic cells in mole and choriocarcinoma. The 4.0kb c-fms transcript has been localized to the syncytiotrophoblast, especially the highly differentiated syncytiotrophoblast in the second and third trimesters and S typed trophoblastic cells in mole and choriocarcinoma. Moreover, the 4.0kb c-sis transcript has been localized to the cytotrophoblast in early placenta, but not detected in mole or choriocarcinoma. First, these results suggest that the stage and site specific expression of c-myc, c-fms and c-sis proto-oncogenes are clearly related to the proliferation, development and differentiation of normal trophoblastic cells. Second, the expression of c-myc, c-fms proto-oncogenes may be of particular importance in the tumorigenesis and progression of trophoblastic disease.