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Int J Clin Exp Pathol 2013;6(3):458-468

Original Article
Expression of Eag1 K+ channel and ErbBs in human pituitary adeno-mas: cytoskeleton
arrangement patterns in cultured cells

Margarita González del Pliego, Elsa Aguirre-Benítez, Karina Paisano-Cerón, Irene Valdovinos-Ramírez, Carlos Rangel-Morales, Verónica
Rodríguez-Mata, Carmen Solano-Agama, Dolores Martín-Tapia, María Teresa de la Vega, Miguel Saldoval-Balanzario, Javier Camacho, María
Eugenia Mendoza-Garrido

Department of Embryology and Department of Histology, Medical Faculty, Autonomous National University of Mexico, Department of Physiol-
ogy, Biophysics and Neurosciences and Department of Pharmacology, Center for Research and Advanced Studies, I.P.N., Neurosurgery Ser-
vice, Medical Center “La Raza”, Social Security Medical Institute, México D.F., México

Received December 10, 2012; Accepted January 15, 2013; Epub February 15, 2013; Published March 1, 2013

Abstract: Pituitary adenomas can invade surrounded tissue, but the mechanism remains elusive. Ether à go-go-1 (Eag1) potassium channel
and epidermal growth factor receptors (ErbB1 and ErbB2) have been associated to invasive phenotypes or poor prognosis in cancer patients.
However, cells arrange their cytoskeleton in order to acquire a successful migration pattern. We have studied ErbBs and Eag1 expression, and
cytoskeleton arrangements in 11 human pituitary adenomas. Eag1, ErbB1 and ErbB2 expression were studied by immunochemistry in tissue
and cultured cells. The cytoskeleton arrangement was analyzed in cultured cells by immunofluorescence. Normal pituitary tissue showed
ErbB2 expression and Eag1 only in few cells. However, Eag1 and ErbB2 were expressed in all the tumors analyzed. ErbB1 expression was
observed variable and did not show specificity for a tumor characteristic. Cultured cells from micro- and macro-adenomas clinically functional
organize their cytoskeleton suggesting a mesenchymal pattern, and a round leucocyte/amoeboid pattern from invasive clinically silent
adenoma. Pituitary tumors over-express EGF receptors and the ErbB2 repeated expression suggests is a characteristic of adenomas. Eag 1
was express, in different extent, and could be a therapeutic target. The cytoskeleton arrangements observed suggest that pituitary tumor cells
acquire different patterns: mesenchymal, and leucocyte/amoeboid, the last observed in the invasive adenomas. Amoeboid migration pattern
has been associated with high invasion capacity. (IJCEP1212015).

Keywords: Pituitary adenomas, ErbBs, Eag1, cytoskeleton, invasion, cell culture

Address correspondence to: Dr. María Eugenia Mendoza-Garrido, Department of Physiology, Biophysics and Neuroscience, Center for
Research and Advanced Studies, National Polytechnic Institute, Av. IPN No. 2508, Col. San Pedro Zacatenco, Mexico City, Mexico 07360. Tel:
(25) 55-5747-3800, Ext. 5122; Fax: (25) 55-5747-3754; E-mail: mmendoza@fisio.cinvestav.mx