c-myc, c-erbB-2, c-fms and bcl-2 oncoproteins. Expression in normal placenta, partial and complete mole, and choriocarcinoma.
OBJECTIVE
To determine the expression of bcl-2, c-myc, c-fms and c-erbB-2 oncoproteins in normal placentas, partial and complete hydatidiform moles, and choriocarcinomas and to examine the possible presence of mutations in the K-ras gene in complete moles and choriocarcinomas.


METHODS
The expression of the above oncoproteins was determined immunohistochemically by specific antibodies for these proteins on formalin-fixed paraffin sections of 18 normal placentas, 17 partial moles, 25 complete moles and 11 choriocarcinomas. This was followed by polymerase chain reaction analysis (exons 12 and 13) of K-ras gene for possible mutations in complete moles and choriocarcinomas.


RESULTS
Expression of c-fms oncoprotein appeared confined to the cytoplasm of syncytiotrophoblastic cells. The c-fms protein staining intensity of the syncytiotrophoblastic layer showed no significant difference among the four gestational tissues. c-erbB-2 antibody expression was confined to the cellular membrane of the extravillous trophoblast. When compared with normal placenta or partial mole, the expression of c-erbB-2 protein was significantly stronger in complete mole (P < .0001 and P < .0001, respectively) and choriocarcinoma (P < .0001 and P < .0001, respectively). Expression of bcl-2 protein was significantly stronger in the syncytiotrophoblast in complete mole and choriocarcinoma as compared to both normal placenta and partial mole (P < .0001 and P < .0001, respectively). Staining of c-myc of the syncytiotrophoblastic layer was significantly stronger in placenta, complete mole and choriocarcinoma than in partial mole (P < .0001, P < .0001 and P < .0001, respectively). Mutation in K-ras gene was not found in any of the 22 complete moles or 11 choriocarcinomas examined.


CONCLUSIONS
Our data suggest that c-myc, c-erbB-2, c-fms and bcl-2 oncoproteins may be important in the pathogenesis of complete mole and choriocarcinoma. However, while both complete mole and choriocarcinoma were characterized by overexpression of c-myc, c-erbB-2 and bcl-2, partial mole generally did not strongly express these three oncoproteins.
Fulop
V
V
Department of Obstetrics and Gynecology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA.
Mok
S C
SC
Genest
D R
DR
Szigetvari
I
I
Cseh
I
I
Berkowitz
R S
RS
D002462:Cell Membrane / Q000737:chemistry; D002822:Choriocarcinoma / Q000737:chemistry*; D003593:Cytoplasm / Q000737:chemistry; D005260:Female; D011905:Genes, ras / Q000235:genetics; D006801:Humans; D006828:Hydatidiform Mole / Q000737:chemistry*; D007150:Immunohistochemistry; D009154:Mutation; D010920:Placenta / Q000737:chemistry*; D016133:Polymerase Chain Reaction; D011247:Pregnancy; D011518:Proto-Oncogene Proteins / Q000032:analysis*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000032:analysis; D016271:Proto-Oncogene Proteins c-myc / Q000032:analysis; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000032:analysis; D016186:Receptor, Macrophage Colony-Stimulating Factor / Q000032:analysis; D014327:Trophoblasts / Q000737:chemistry; D014594:Uterine Neoplasms / Q000737:chemistry*
D011518:Proto-Oncogene Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D016271:Proto-Oncogene Proteins c-myc; D018719:Erb-b2 Receptor Tyrosine Kinases; D016186:Receptor, Macrophage Colony-Stimulating Factor