β3 integrin expression is required for invadopodia-mediated ECM degradation in lung carcinoma cells

PLoS One. 2017 Aug 2;12(8):e0181579. doi: 10.1371/journal.pone.0181579. eCollection 2017.

Abstract

Cancer related deaths are primarily due to tumor metastasis. To facilitate their dissemination to distant sites, cancer cells develop invadopodia, actin-rich protrusions capable of degrading the surrounding extracellular matrix (ECM). We aimed to determine whether β3 integrin participates in invadopodia formed by lung carcinoma cells, based on our previous findings of specific TGF-β induction of β3 integrin dependent metastasis in animal models of lung carcinoma. In this study, we demonstrate that lung carcinoma cells form invadopodia in response to TGF-β exposure. Invadopodia formation and degradation activity is dependent on β3 integrin expression since β3 integrin deficient cells are not able to degrade gelatin-coated surfaces. Even more, transient over-expression of SRC did not restore invadopodia formation in β3 integrin deficient cells. Finally, we observed that blockade of PLC-dependent signaling leads to more intense labeling for β3 integrin in invadopodia. Our results suggest that β3 integrin function, and location, in lung cancer cells are essential for invadopodia formation, and this integrin regulates the activation of different signal pathways necessary for the invasive structure. β3 integrin has been associated with poor prognosis and increased metastasis in several carcinoma types, including lung cancer. Our findings provide new evidence to support the use of targeted therapies against this integrin to combat the onset of metastases.

MeSH terms

  • A549 Cells
  • Carcinoma, Non-Small-Cell Lung / metabolism*
  • Cell Adhesion
  • Cell Line, Tumor
  • Extracellular Matrix / metabolism*
  • Humans
  • Integrin beta3 / metabolism*
  • Lung Neoplasms / metabolism*
  • Neoplasm Metastasis
  • Podosomes / drug effects
  • Podosomes / metabolism*
  • Signal Transduction
  • Transforming Growth Factor beta / pharmacology*
  • src-Family Kinases / metabolism

Substances

  • Integrin beta3
  • Transforming Growth Factor beta
  • src-Family Kinases

Grants and funding

RP was supported by Spanish Ministry of Economy and Competitiveness /Torres Quevedo program PTQ-11-04778. This work was funded by Institute of Health Carlos III grants [PI10/02131 (AR) and PI13/02313 (AR)] and Spanish Ministry of Economy and Competitiveness grants [DPI2012-38090-C03-02(COS) and DPI2015-64221-C2-2 (COS)]. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.