alpha 6 beta 1-Integrin, a major cell surface carrier of beta 1-6-branched oligosaccharides, mediates migration of EJ-ras-transformed fibroblasts on laminin-1 independently of its glycosylation state

• Autor(a) principal: Jasiulionis,Miriam Galvonas [UNIFESP]
• Data de Publicação: 1996
• Outros Autores: Chammas, Roger, Ventura, Armando M., Travassos, Luiz Rodolpho [UNIFESP], Brentani, Ricardo Renzo [UNIFESP]
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UNIFESP
• Texto Completo: http://cancerres.aacrjournals.org/content/56/7/1682; http://repositorio.unifesp.br/handle/11600/43246

EJ-ras oncogene-induced malignant transformation is characterized by a series of changes in cell surface carbohydrates and cell-cell and cell-matrix interactions, Here, we show that EJ-ras-transformed NIH-3T3 fibroblasts acquired a migratory phenotype on laminin-1 surfaces, Such a phenotype was accompanied by overexpression of: (a) functional alpha 6 beta 1, but not other laminin binding beta 1-integrins; and (b) glycoconjugates on the cell surface bearing large oligosaccharides recognized by leukoagglutinin from Phaseolus vulgar is (L-PHA). The internal pool of pre-beta 1-integrins was differently regulated in EJ-ras-transformed cells compared with non-transfected fibroblasts. Conversion of pre-beta 1- into mature beta 1-integrins was faster in EJ-ras-transformed cells, a process associated with the overexpression of the alpha 6-chain, Overexpression of L-PHA-reactive oligosaccharides is dependent on the activity of N-acetylglucosaminyltransferase V, which is increased in transformed cells [J. W. Dennis et al., Science (Washington DC), 236: 582-585, 1987], We show that beta 1-integrins were the major carriers of L-PHA-reactive oligosaccharides on the cell surface, This glycosylation pattern, however, was not necessary for either the cell surface expression of beta 1-integrins or their functional activity in the migratory response to laminin-1, Moreover, EJ-ras-transformed fibroblasts aggregated spontaneously, These effects were not observed in c-jun-transfected fibroblasts, which were unable to migrate on laminin, did not overexpress either beta 1-integrins or L-PHA-reactive oligosaccharides, and did not self-aggregate.