We aimed to evaluate aromatase, estrogen receptor α (ERα), estrogen receptor β (ERβ), pituitary tumor transforming gene (PTTG), and fibroblast growth factor 2 (FGF2) expressions in GH-secreting adenomas, and investigate their correlation with clinical, pathologic, and radiologic parameters.
Immunohistochemistry of the excised tumor revealed strong immunoreactivity for VEGF and FGF-2, two potent angiogenic factors, and CD31 (an endothelial marker) indicating high vascularization of the adenoma.
While normal pituitary expresses GFG but not FGF-2, pituitary adenomas express FGF-2 and have reduced levels of GFG; aggressive and recurrent adenomas expressed more FGF than GFG mRNA.
The functional significance of these changes was assessed by affinity co-electrophoresis, which showed that the affinity of adenoma HS for bFGF was 10-fold greater than that of the carcinoma HS (Kd 220 nM vs. 2493 nM, respectively).