The knocking down of the oncoprotein Golgi phosphoprotein 3 in T98G cells of glioblastoma multiforme disrupts cell migration by affecting focal adhesion dynamics in a focal adhesion kinase-dependent manner

PLoS One. 2019 Feb 19;14(2):e0212321. doi: 10.1371/journal.pone.0212321. eCollection 2019.

Abstract

Golgi phosphoprotein 3 (GOLPH3) is a conserved protein of the Golgi apparatus that in humans has been implicated in tumorigenesis. However, the precise function of GOLPH3 in malignant transformation is still unknown. Nevertheless, clinicopathological data shows that in more than a dozen kinds of cancer, including gliomas, GOLPH3 could be found overexpressed, which correlates with poor prognosis. Experimental data shows that overexpression of GOLPH3 leads to transformation of primary cells and to tumor growth enhancement. Conversely, the knocking down of GOLPH3 in GOLPH3-overexpressing tumor cells reduces tumorigenic features, such as cell proliferation and cell migration and invasion. The cumulative evidence indicate that GOLPH3 is an oncoprotein that promotes tumorigenicity by a mechanism that impact at different levels in different types of cells, including the sorting of Golgi glycosyltransferases, signaling pathways, and the actin cytoskeleton. How GOLPH3 connects mechanistically these processes has not been determined yet. Further studies are important to have a more complete understanding of the role of GOLPH3 as oncoprotein. Given the genetic diversity in cancer, a still outstanding aspect is how in this inherent heterogeneity GOLPH3 could possibly exert its oncogenic function. We have aimed to evaluate the contribution of GOLPH3 overexpression in the malignant phenotype of different types of tumor cells. Here, we analyzed the effect on cell migration that resulted from stable, RNAi-mediated knocking down of GOLPH3 in T98G cells of glioblastoma multiforme, a human glioma cell line with unique features. We found that the reduction of GOLPH3 levels produced dramatic changes in cell morphology, involving rearrangements of the actin cytoskeleton and reduction in the number and dynamics of focal adhesions. These effects correlated with decreased cell migration and invasion due to affected persistence and directionality of cell motility. Moreover, the knocking down of GOLPH3 also caused a reduction in autoactivation of focal adhesion kinase (FAK), a cytoplasmic tyrosine kinase that regulates focal adhesions. Our data support a model in which GOLPH3 in T98G cells promotes cell migration by stimulating the activity of FAK.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Brain Neoplasms / metabolism
  • Brain Neoplasms / pathology
  • Cell Line, Tumor
  • Cell Movement
  • Cell Proliferation
  • Focal Adhesion Protein-Tyrosine Kinases / metabolism*
  • Focal Adhesions / physiology*
  • Glioblastoma / metabolism
  • Glioblastoma / pathology
  • Humans
  • Membrane Proteins / antagonists & inhibitors
  • Membrane Proteins / genetics
  • Membrane Proteins / metabolism*
  • Phosphorylation
  • RNA Interference
  • RNA, Small Interfering / metabolism

Substances

  • GOLPH3 protein, human
  • Membrane Proteins
  • RNA, Small Interfering
  • Focal Adhesion Protein-Tyrosine Kinases

Grants and funding

This work was funded by grants 1130710, 1161252 (G.A.M.) and 1171649 (P.V.B.) from Fondo Nacional de Desarrollo Científico y Tecnológico of Chile (FONDECYT; http://www.conicyt.cl/fondecyt), EQM150118 (P.V.B.) from Fondo de Equipamiento Científico y Tecnológico of Chile (FONDEQUIP; http://www.conicyt.cl/fondequip), NC130011 (G.A.) to Nucleo Milenio Biology of Neuropsiquiatric Disorders NuMIND from Iniciativa Científica Milenio del Ministerio de Economía, Fomento y Turismo of Chile (http://www.iniciativamilenio.cl), and from Dirección de Investigación y Desarrollo de la Universidad Austral de Chile (DID-UACh; http://investigacion.uach.cl) (G.A.M. and P.V.B.). C.A. and C.L. were supported by fellowships 21120450 and 21130116, respectively, from Comisión Nacional de Investigación Científica y Tecnológica of Chile (CONICYT; http://www.conicyt.cl). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.