title: GH3 tumor pituitary cell cytoskeleton and plasma membrane arrangement are determined by extracellular matrix proteins: implications on motility, proliferation and hormone secretion.
abstract: The extracellular matrix (ECM) influences different physiological and pathophysiological aspects of the cell. The ECM consists in a complex network of macromolecules with characteristic biochemical properties that allow cells to sense their environments inducing different signals and changing cell behavior. The purpose of the present study was to evaluate the participation of different ECM proteins in cell morphology and its implication on motility, proliferation and hormone secretion in GH3 cells, a tumor pituitary cell. GH3 cells were cultured with a defined medium on collagens I/III and IV, fibronectin and laminin. GH3 cells express α2 integrin subunit de novo. The cells responded to the ECM proteins with differentiated cell surface morphologies and membrane protrusions. A rounded shape with small membrane blebs, weak substrate adhesion and high motility was observed in cells on C I/III and fibronectin, while on C IV and laminin cells were viewed elongated and adhered. Differences on actin cytoskeleton, cytoskeletal-associated vinculin and phospho-MLC showed that ECM proteins determine the cytoskeleton organization. Cell proliferation showed dependency on the ECM protein, observing a higher rate in cells on collagen I/III. Prolactin secretion was higher in cells with small blebs, but an unchangeable response to EGF was obtained with the ECM proteins, suggesting is a consequence of cortical actin arrangement. We ascribe the functional differences of the GH3 cells to the cytoskeletal organization. Overall, the data showed that ECM plays a critical role in GH3 cells modulating different cellular comportment and evidenced the importance of the ECM composition of pituitary adenomas.
authors: Department of Physiology, Biophysics and Neuroscience, CINVESTAV-IPN Mexico City, Mexico.
authors: Erika
authors: E
authors: Azorín
authors: Department of Physiology, Biophysics and Neuroscience, CINVESTAV-IPN Mexico City, Mexico.
authors: Beatriz
authors: B
authors: Romero-Pérez
authors: Department of Physiology, Biophysics and Neuroscience, CINVESTAV-IPN Mexico City, Mexico.
authors: Carmen
authors: C
authors: Solano-Agama
authors: Department of Physiology, Biophysics and Neuroscience, CINVESTAV-IPN Mexico City, Mexico.
authors: María T
authors: MT
authors: de la Vega
authors: Department of Physiology, Biophysics and Neuroscience, CINVESTAV-IPN Mexico City, Mexico.
authors: César G
authors: CG
authors: Toriz
authors: Department of Physiology, Biophysics and Neuroscience, CINVESTAV-IPN Mexico City, Mexico.
authors: Blanca
authors: B
authors: Reyes-Márquez
authors: Central Laboratories, CINVESTAV-IPN Mexico City, Mexico.
authors: Sirenia
authors: S
authors: González-Pozos
authors: Central Laboratories, CINVESTAV-IPN Mexico City, Mexico.
authors: Víctor H
authors: VH
authors: Rosales-García
authors: Department of Embryology, Medical Faculty, UNAM Mexico City, Mexico.
authors: Margarita González
authors: MG
authors: Del Pliego
authors: Guanajuato University Guanajuato, Gto., Mexico.
authors: Myrna
authors: M
authors: Sabanero
authors: Department of Physiology, Biophysics and Neuroscience, CINVESTAV-IPN Mexico City, Mexico.
authors: María E
authors: ME
authors: Mendoza-Garrido
keywords: ECM proteins; GH3 cells; Prl secretion; actin cytoskeleton organization; cell membrane organization; proliferation; α2 integrin sub-unit