Signalling pathway alterations in pituitary adenomas: involvement of Gsalpha, cAMP and mitogen-activated protein kinases.
Despite extensive research on sporadic pituitary adenomas, it is not yet possible to assign one protein alteration to one specific type of pituitary adenomas. Nevertheless, alterations of the cAMP pathway appear to be molecular hallmarks of most growth hormone (GH)-secreting adenomas. However, these alterations do not confer specific phenotypes to patients carrying these alterations. In this review, we summarise the literature regarding signalling alterations observed in GH-secreting adenomas. We focus on Gsalpha alterations and their possible cross-talk with the extracellular signal-related kinase (ERK)1/2 pathway. In the light of results obtained on human somatotroph adenoma cells in primary culture and on models of murine somatotroph cell lines, we postulate a crucial role for ERK1/2 in GH-secreting adenomas downstream of cAMP pathway alterations that might impact the tumoural phenotype.
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CRN2M, UMR 6231, CNRS, Department of Neuroendocrinology-Neuroimmunology, Institut Fédératif Jean-Roche, Faculté de Médecine Secteur Nord, Université de Méditerranée, Marseille, France.
Barlier
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Enjalbert
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Gérard
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C
D000236:Adenoma / Q000201:enzymology / Q000378:metabolism* / Q000473:pathology; D000242:Cyclic AMP / Q000378:metabolism*; D019205:GTP-Binding Protein alpha Subunits, Gs / Q000378:metabolism*; D013006:Growth Hormone / Q000378:metabolism; D006801:Humans; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D010911:Pituitary Neoplasms / Q000201:enzymology / Q000378:metabolism* / Q000473:pathology; D015398:Signal Transduction
D013006:Growth Hormone; D000242:Cyclic AMP; D020928:Mitogen-Activated Protein Kinases; D019205:GTP-Binding Protein alpha Subunits, Gs