RT info:eu-repo/semantics/article T1 Multifunctional cells in human pituitary adenomas: Implications for paradoxical secretion and tumorigenesis A1 Senovilla González, Laura A1 Núñez Llorente, Lucía A1 Campos, José María de A1 Luis Román, Daniel Antonio de A1 Romero Bobillo, Enrique A1 Sánchez, Ana A1 García-Sancho Martín, Francisco Javier A1 Villalobos Jorge, Carlos K1 Multifunctional cells K1 Células multifuncionales K1 Pituitary Adenomas K1 Adenomas pituitarios K1 Tumorigenesis K1 Tumorigénesis AB Pituitary adenomas are very common in humans. They are of monoclonal origin, very heterogeneous, and produce frequently paradoxical secretion. The normal anterior pituitary (AP) contains some unorthodox multifunctional cells able to store more than one AP hormone (polyhormonal) and/or to express multiple hypothalamic-releasing hormone receptors (multiresponsive). Multifunctional AP cells seem to be involved in plasticity processes such as transdifferentiation or paradoxical secretion. Here, we have characterized the single-cell phenotypes of 15 human pituitary tumors, including prolactinomas, nonfunctioning adenomas, and adenomas from multiple endocrine neoplasia type I (MEN-I) and pituitary Cushing’s disease patients. Individual tumor cells were typed according to expression of AP hormones and hypothalamic-releasing hormone receptors by combination of calcium imaging and multiple sequential immunocytochemistry in the same cells. We found a large heterogeneity among the different tumors. In eight of the 15 tumors studied, more than 80% of the cells presented a multifunctional phenotype. This may explain the occurrence of paradoxical secretion. In addition, our results suggest that human pituitary adenomas might derive from multifunctional cells. This is consistent with the existence of a link between pituitary plasticity and tumorigenesis. PB Oxford University Press SN 1945-7197 YR 2004 FD 2004 LK http://uvadoc.uva.es/handle/10324/45071 UL http://uvadoc.uva.es/handle/10324/45071 LA eng NO The Journal of Clinical Endocrinology & Metabolism, 2004, vol. 89, n. 9. p. 4545-4552 NO Producción Científica DS UVaDOC RD 18-may-2024