Moreover, the role of BMP-4 which stimulates prolactinoma development through the Smad signalling cascade is described and its role as putative drug target for the treatment of prolactinomas is discussed.
BMP-4 transcript and protein are differentially expressed and show increase in the majority of prolactinomas relative to normal pituitary, whereas the majority of other adenoma subtypes show reduced expression relative to both prolactinoma and normal pituitaries.
The differential expression and action of BMP-4 in prolactinomas and corticotrophinomas highlights the importance of studying a gene with contrasting actions in two cell lineages of the same organ in order to understand the pituitary transformation process.
Bone morphogenetic protein-4 (BMP-4), a member of the transforming growth factor-Beta(TGF-Beta) family, is overexpressed in different prolactinoma models and induces the development of these lineage adenomas.
BMP-4 stimulates, and noggin blocks, cell proliferation and the expression of c-Myc in human prolactinomas, whereas BMP-4 has no action in other human pituitary tumors.