Objective: To study the expression of vascular endothelial growth factors (VEGFs), placental growth factor (PLGF) and their receptors (VEGFR-1, -2, -3) and their regulators (IL-6, CD147) in normal placenta and gestational trophoblastic disease (GTD) in order to evaluate their potential role in the biology of GTD.
Study design: Paraffin sections of 10 normal, first-trimester placentas, 10 partial moles, 10 complete moles, 5 choriocarcinomas and 5 placental site trophoblastic tumors (PSTTs) were studied immunohistochemically for expression of VEGFR-1, VEGFR-2, VEGFR-3, IL-6, PLGF and CD147. Immunolocalization of VEGF, Angiopoietin-1 and Angiopoietin-2 was performed on 5 choriocarcinomas and 5 PSTTs. The levels of VEGF and VEGFR-2 were determined in supernatants and lysates of normal trophoblast, JEG-3 and JAR choriocarcinoma cells with electrochemiluminescence assays.
Results: The normal placenta had significantly stronger expression of VEGFR-2 than did those of partial and complete mole (p = 0.001, p = 0.003). VEGF, Angiopoietin-1 and Angiopoietin-2 expression in PSTT were significantly higher than those in choriocarcinoma (p = 0.002, p= 0.01, p = 0.038). Choriocarcinoma showed stronger intensity of staining for VEGFR-3 than did normal placenta, partial and complete mole (p = 0.036, p = 0.038, p = 0.05). Choriocarcinoma had significantly stronger staining of CD147 than did partial and complete mole (p<0.01, p<0.01). PSTT exhibited significantly stronger staining for IL-6 than did choriocarcinoma (p = 0.03).
Conclusion: PSTTs exhibited strong staining for VEGF, and choriocarcinoma showed strong staining for VEGFR-3. Agents that inhibit the activity of VEGF and VEGF receptors may prove to be useful in the therapy of gestational trophoblastic neoplasia.