Pituitary Gene Signalling Pathway

Abstract

The anterior pituitary contains five trophic hormone‐secreting cells, including adrenocorticotropic hormone (ACTH)‐secreting corticotrophs, luteinising hormone (LH)‐/follicle‐stimulating hormone (FSH)‐secreting gonadotrophs, thyroid‐stimulating hormone (TSH)‐secreting thyrotrophs, growth hormone (GH)‐secreting somatotrophs and prolactin (PRL)‐secreting lactotrophs. Each cell is differentiated from stem cells by intrinsic and extrinsic signals. Pituitary hormone synthesis and secretion is strictly regulated by stimulating hormone, mainly from the hypothalamus, and suppressing hormone, predominantly from peripheral tissues, as a negative feedback system. Pituitary adenomas are the most common pathological state in the anterior pituitary. Several impaired signalling pathways related with pituitary tumourigenesis have been shown in human and animal studies. These include cAMP‐PKA signalling pathway, cell cycle signalling pathway and epigenetic changes. These disruptions could induce not only pituitary cell proliferation but also hormone hypersecretion. Key Concepts The pituitary gland contains five trophic cells. These cells are differentiated from stem cells by intrinsic and extrinsic signallings. Hormone synthesis and secretion is regulated by stimulatory and inhibitory signallings. Pituitary adenomas are the most common pathological state in the anterior pituitary. Human and animal studies identified several genes related to pituitary adenomas. Impaired cAMP‐PKA and/or cell cycle signalling pathway has an important role in pituitary tumourigenesis. Epigenetic changes deregulate gene signallings related to pituitary tumourigenesis.