EGF-stimulated activation of Rab35 regulates RUSC2-GIT2 complex formation to stabilize GIT2 during directional lung cancer cell migration

Cancer Lett. 2016 Aug 28;379(1):70-83. doi: 10.1016/j.canlet.2016.05.027. Epub 2016 May 26.

Abstract

Non-small cell lung cancer (NSCLC) remains one of the most metastasizing tumors, and directional cell migration is critical for targeting tumor metastasis. GIT2 has been known to bind to Paxillin to control cell polarization and directional migration. However, the molecular mechanisms underlying roles of GIT2 in controlling cell polarization and directional migration remain elusive. Here we demonstrated GIT2 control cell polarization and direction dependent on the regulation of Golgi through RUSC2. RUSC2 interacts with SHD of GIT2 in various lung cancer cells, and stabilizes GIT2 (Mazaki et al., 2006; Yu et al., 2009) by decreasing degradation and increasing its phosphorylation. Silencing of RUSC2 showed reduced stability of GIT2, defective Golgi reorientation toward the wound edge and decreased directional migration. Moreover, short-term EGF stimulation can increase the interaction between RUSC2 and GIT2, prolonged stimulation leads to a decrease of their interaction through activating Rab35. Silencing of Rab35 also reduced stability and phosphorylation of GIT2 and decreased cell migration. Taken together, our study indicated that RUSC2 participates in EGFR signaling and regulates lung cancer progression, and may be a new therapeutic target against lung cancer metastasis.

Keywords: Directional migration; GIT2; Non-small cell lung cancer; Protein degradation; RUSC2.

MeSH terms

  • A549 Cells
  • Carcinoma, Non-Small-Cell Lung / enzymology*
  • Carcinoma, Non-Small-Cell Lung / genetics
  • Carcinoma, Non-Small-Cell Lung / pathology
  • Carrier Proteins / genetics
  • Carrier Proteins / metabolism*
  • Cell Movement / drug effects*
  • Enzyme Activation
  • Epidermal Growth Factor / pharmacology*
  • ErbB Receptors / agonists
  • ErbB Receptors / metabolism
  • GTPase-Activating Proteins / genetics
  • GTPase-Activating Proteins / metabolism*
  • Golgi Apparatus / drug effects
  • Golgi Apparatus / metabolism
  • HEK293 Cells
  • Humans
  • Lung Neoplasms / enzymology*
  • Lung Neoplasms / genetics
  • Lung Neoplasms / pathology
  • Phosphorylation
  • Protein Binding
  • Protein Interaction Domains and Motifs
  • Protein Stability
  • Protein Transport
  • RNA Interference
  • Signal Transduction / drug effects
  • Time Factors
  • Transfection
  • rab GTP-Binding Proteins / genetics
  • rab GTP-Binding Proteins / metabolism*
  • src Homology Domains

Substances

  • Carrier Proteins
  • GIT2 protein, human
  • GTPase-Activating Proteins
  • RUSC2 protein, human
  • Epidermal Growth Factor
  • EGFR protein, human
  • ErbB Receptors
  • RAB35 protein, human
  • rab GTP-Binding Proteins