Combined inhibition of rho-associated protein kinase and EGFR suppresses the invasive phenotype in EGFR-dependent lung cancer cells.
BACKGROUND
Lung cancer remains the leading cause of cancer-related mortality worldwide, with metastatic disease frequently a prominent feature at the time of diagnosis. The role of NSCLC-derived EGFR mutations in cancer cell proliferation and survival has been widely reported, but little is known about the function of these mutations in invasive growth and metastasis. In this study, we sought to evaluate the intrinsic invasive properties of NSCLC cells with differing EGFR status and examine possible therapeutic targets that can abrogate invasive growth.


METHODS
Collagen-based assays and 3D cell cultures were used to assess morphological features, actin cytoskeleton dynamics and the invasive capacity of NSCLC cell lines with differing EGFR status. The role of the RhoA/ROCK/MYPT1 and EGFR/HER pathways in NSCLC-related invasion was investigated by pharmacological inhibition and RNA interference techniques.


RESULTS
We demonstrate a positive correlation between EGFR mutational/amplification status and invasive capacity. Knockdown of wild-type and mutant EGFR leads to depletion of active and total MYPT1 levels. Combined pharmacological inhibition or genetic ablation of ROCK/EGFR suppresses the hallmarks of cancer cells and abrogates the invasive phenotype in EGFR-dependent NSCLC cells.


CONCLUSIONS
These observations suggest that combined targeting of the ROCK and EGFR/HER pathways may be a potential therapeutic approach in limiting invasive growth in NSCLC.
Laboratory of Molecular Oncology and Department of Medical Oncology, Oncologisch Centrum, Universitair Ziekenhuis Brussel, Belgium. Electronic address: iumelo@vub.ac.be.
Ijeoma Adaku
IA
Umelo
Laboratory of Experimental Cancer Research and Department of Radiation Therapy and Experimental Cancer Research, Universitair Ziekenhuis Ghent, Belgium. Electronic address: Olivier.DeWever@UGent.be.
Olivier De
OD
Wever
Laboratory of Molecular Oncology and Department of Medical Oncology, Oncologisch Centrum, Universitair Ziekenhuis Brussel, Belgium; Laboratory for Biotechnology, Department of Healthcare, Erasmushogeschool Brussel, Brussels, Belgium. Electronic address: Peter.kronenberger@vub.ac.be.
Peter
P
Kronenberger
Laboratory of Molecular Oncology and Department of Medical Oncology, Oncologisch Centrum, Universitair Ziekenhuis Brussel, Belgium. Electronic address: alfinoor@vub.ac.be.
Alfiah
A
Noor
Laboratory of Molecular Oncology and Department of Medical Oncology, Oncologisch Centrum, Universitair Ziekenhuis Brussel, Belgium. Electronic address: Erik.Teugels@uzbrussel.be.
Erik
E
Teugels
Laboratory of Molecular Oncology and Department of Medical Oncology, Oncologisch Centrum, Universitair Ziekenhuis Brussel, Belgium. Electronic address: gangchen@vub.ac.be.
Gang
G
Chen
Laboratory of Experimental Cancer Research and Department of Radiation Therapy and Experimental Cancer Research, Universitair Ziekenhuis Ghent, Belgium. Electronic address: Marc1.Bracke@UGent.be.
Marc
M
Bracke
Laboratory of Molecular Oncology and Department of Medical Oncology, Oncologisch Centrum, Universitair Ziekenhuis Brussel, Belgium. Electronic address: Jacques.Degreve@uzbrussel.be.
Jacques De
JD
Grève
D002289:Carcinoma, Non-Small-Cell Lung / Q000188:drug therapy / Q000378:metabolism; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D066246:ErbB Receptors / Q000037:antagonists & inhibitors*; D006801:Humans; D008175:Lung Neoplasms / Q000188:drug therapy* / Q000378:metabolism; D009154:Mutation / Q000187:drug effects; D009361:Neoplasm Invasiveness / Q000517:prevention & control*; D010641:Phenotype; D047428:Protein Kinase Inhibitors / Q000494:pharmacology*; D015398:Signal Transduction / Q000187:drug effects; D054460:rho-Associated Kinases / Q000037:antagonists & inhibitors*
D047428:Protein Kinase Inhibitors; C512478:EGFR protein, human; D066246:ErbB Receptors; D054460:rho-Associated Kinases
Afatinib; EGFR; Invasion; Non-small cell lung cancer; ROCK; Y-27632