Immunolocalization and quantitation of transforming growth factor alpha in hydatidiform mole

Complete hydatidiform mole (CHM), a condition related to abnormal gestation, occurs predominantly in the young reproductive age group and has a high prevalence rate in the Trivandrum region, occurring in 1.2% of deliveries. Transforming growth factor alpha (TGF-alpha) is an important growth regulatory molecule, the location and function of which at the human fetomaternal interface in CHM remains to be determined. The present study examined the presence of TGF-alpha in the normal and complete molar placenta and decidua throughout gestation. A total of 149 complete molar placental tissue samples and 96 normal placental tissue samples were evaluated for TGF-alpha expression by immunohistochemistry and 50 each of CHM and normal placental tissue for TGF-alpha concentration by radioimmunoassay. The peptide was localized immunocytochemically with a monoclonal anti-TGF-alpha antibody on paraffin-embedded tissue using the avidin-biotin complex peroxidase technique with aminoethyl carbazole as the chromogen. In molar placenta, villous trophoblast cells (syncytiotrophoblasts and cytotrophoblasts) showed intense cytoplasmic staining at all gestational ages compared to normal placenta of the same gestational age. The tissue concentration of TGF-alpha was highly overexpressed in the molar placenta (10-1000 fold) compared to that in the normal placenta. The results indicate that TGF-alpha is present in trophoblasts throughout human gestation and may provide additional growth advantage to maintenance of the hyperproliferative condition in trophoblastic tumors.