C3G knock-down enhances migration and invasion by increasing Rap1-mediated p38α activation, while it impairs tumor growth through p38α-independent mechanisms.
C3G, a Guanine nucleotide Exchange Factor (GEF) for Rap1 and R-Ras, has been shown to play important roles in development and cancer. Previous studies determined that C3G regulates cell death through down-regulation of p38α MAPK activity. Here, we found that C3G knock-down in MEFs and HCT116 cells promotes migration and invasion through Rap1-mediated p38α hyper-activation. These effects of C3G were inhibited by Rap1 knock-down or inactivation. The enhanced migration observed in C3G depleted HCT116 cells was associated with reduction in E-cadherin expression, internalization of ZO-1, actin cytoskeleton reorganization and decreased adhesion. We also found that matrix metalloproteases MMP2 and MMP9 are involved in the pro-invasive effect of C3G down-regulation. Additionally, our studies revealed that both C3G and p38α collaborate to promote growth of HCT116 cells in vitro and in vivo, possibly by enhancing cell survival. In fact, knocking-down C3G or p38α individually or together promoted cell death in vitro, although only the double C3G-p38α silencing was able to increase cell death within tumors. Notably, we found that the pro-tumorigenic function of C3G does not depend on p38α or Rap1 activation. Altogether, our studies uncover novel mechanisms by which C3G controls key aspects of tumorigenesis.
Departamento de Bioquímica y Biología Molecular II, Facultad de Farmacia, Universidad Complutense de Madrid, Madrid, Spain.|Instituto de Investigación Sanitaria del Hospital Clínico San Carlos (IdISSC), Madrid, Spain.
Neibla
N
Priego
Departamento de Bioquímica y Biología Molecular II, Facultad de Farmacia, Universidad Complutense de Madrid, Madrid, Spain.|Instituto de Investigación Sanitaria del Hospital Clínico San Carlos (IdISSC), Madrid, Spain.
María
M
Arechederra
Departamento de Bioquímica y Biología Molecular II, Facultad de Farmacia, Universidad Complutense de Madrid, Madrid, Spain.|Instituto de Investigación Sanitaria del Hospital Clínico San Carlos (IdISSC), Madrid, Spain.
Celia
C
Sequera
Institut d'Investigacions Biomediques August Pi i Sunyer (IDIBAPS), Barcelona, Spain.
Paloma
P
Bragado
Departamento de Bioquímica y Biología Molecular II, Facultad de Farmacia, Universidad Complutense de Madrid, Madrid, Spain.|Instituto de Investigación Sanitaria del Hospital Clínico San Carlos (IdISSC), Madrid, Spain.
Ana
A
Vázquez-Carballo
Departamento de Bioquímica y Biología Molecular II, Facultad de Farmacia, Universidad Complutense de Madrid, Madrid, Spain.|Present address: Department of Cancer Biology, Biomedical Research Building II/III, School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
Álvaro
Á
Gutiérrez-Uzquiza
Centro de Investigación del Cáncer, IBMCC, Departamento de Medicina, Facultad de Medicina, Universidad de Salamanca, Instituto de Investigaciones Biomédicas de Salamanca (IBSAL), Salamanca, Spain.
Víctor
V
Martín-Granado
Translational Cell and Tissue Research, Department of Imaging and Pathology, Leuven University, Leuven, Belgium.
Juan José
JJ
Ventura
Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
Marcelo G
MG
Kazanietz
Centro de Investigación del Cáncer, IBMCC, Departamento de Medicina, Facultad de Medicina, Universidad de Salamanca, Instituto de Investigaciones Biomédicas de Salamanca (IBSAL), Salamanca, Spain.
Carmen
C
Guerrero
Departamento de Bioquímica y Biología Molecular II, Facultad de Farmacia, Universidad Complutense de Madrid, Madrid, Spain.|Instituto de Investigación Sanitaria del Hospital Clínico San Carlos (IdISSC), Madrid, Spain.
Almudena
A
Porras
D000818:Animals; D063646:Carcinogenesis / Q000378:metabolism*; D002465:Cell Movement / Q000502:physiology; D015179:Colorectal Neoplasms / Q000378:metabolism / Q000473:pathology*; D004789:Enzyme Activation / Q000502:physiology; D005347:Fibroblasts / Q000378:metabolism; D055785:Gene Knockdown Techniques; D020735:Guanine Nucleotide-Releasing Factor 2 / Q000378:metabolism*; D045325:HCT116 Cells; D064593:Heterografts; D006801:Humans; D008297:Male; D051379:Mice; D008819:Mice, Nude; D048308:Mitogen-Activated Protein Kinase 14 / Q000378:metabolism*; D009361:Neoplasm Invasiveness / Q000473:pathology; D020827:rap1 GTP-Binding Proteins / Q000378:metabolism*
D020735:Guanine Nucleotide-Releasing Factor 2; D048308:Mitogen-Activated Protein Kinase 14; D020827:rap1 GTP-Binding Proteins
C3G; Rap1; migration; p38 MAPK; tumorigenesis