Targets for pituitary tumor therapy

Abstract

Recent advances in understanding the mechanisms underlying pituitary tumorigenesis will allow identification of novel targets for therapy for these common but often incurable tumors. Pituitary tumor initiation and progression are associated with multiple and acquired disorders. The pituitary gland responds to central and peripheral signals by undergoing reversible hormonal secretory changes and plastic cell growth changes. Underlying pituitary hyperplasia, with or without excess hormone production, or, in contrast, involution or hyposecretion in pituitary cells correlates with pituitary tumor development. Transgenic mouse models of tumor suppressor gene inactivation lead largely to the development of intermediate lobe tumors whereas pituitary-directed growth factor activation predisposes to anterior pituitary tumor development. Results of pituitary-directed pituitary tumor transforming gene (PTTG) inactivation or over-expression support the notion that the trophic environment is permissive for pituitary tumor formation. Understanding the mechanisms underlying pituitary plasticity and their relationship to tumor development will provide subcellular targets for treating both the development and growth of these tumors.