Antibody array strategy for human growth factor secretome profiling of GH-secreting adenomas

Purposes: To test if the antibody array strategy could be utilized to simultaneously detect the secretion of multiple growth factors by human pituitary GH-adenomas and to measure octreotide-induced alterations. Methods: Specimens of human pituitary adenomas were cultured and incubated with or without octreotide for 24 h. Conditional media were analyzed by human growth factor antibody array and VEGF concentrations were measured by ELISA. Media were also analyzed for GH concentrations. p21 expression levels were examined by Western blot of the specimens lysates. Results: The antibody arrays successfully identified growth factors secreted by GH-adenomas in vitro. Octreotide treatment induced both elevations and reductions in growth factors secretion. GH response to octreotide was measured, and in this small-sized study resistant and sensitive GH-adenomas presented with no unique secretome pattern of each of the groups. Octreotide-induced VEGF alterations analyzed by the antibody array and by ELISA were not fully matched. Conclusions: This study suggests that the broad proteomic strategy of antibody arrays may be utilized to study the growth factors secretion pattern of GH-adenomas and its regulation by somatostatin analogs or other compounds.