TY - JOUR
T1 - EGFR-GRB2 protein colocalization is a prognostic factor unrelated to overall EGFR expression or EGFR mutation in lung adenocarcinoma
AU - Toki, Maria I.
AU - Carvajal-Hausdorf, Daniel E.
AU - Altan, Mehmet
AU - McLaughlin, Joseph
AU - Henick, Brian
AU - Schalper, Kurt A.
AU - Syrigos, Konstantinos N.
AU - Rimm, David L.
N1 - Funding Information:
This work was supported by grants from the National Institutes of Health , including Yale SPORE in Lung Cancer Grant P50-CA196530 and Yale Cancer Center Support Grant P30-CA016359 , the OKIBEE support grant (Dr. Syrigos), and support from Gilead Sciences, Inc. The authors also acknowledge the expert assistance of Lori Charette and her staff in the Yale Tissue Microarray Facility division of Yale Pathology Tissue Services for construction of the tissue microarrays used in the study.
Publisher Copyright:
© 2016 International Association for the Study of Lung Cancer. Published by Elsevier Inc. All rights reserved.
PY - 2016/11/13
Y1 - 2016/11/13
N2 - Introduction: EGFR is a therapeutic target in NSCLC for EGFR-mutant patients. Proximity ligation assay (PLA) is a method to detect functional signaling associated protein complexes. Growth factor receptor bound protein 2 (GRB2) is an adaptor protein that binds to the phosphorylated residues of active EGFR. Interaction of EGFR and GRB2 correlates with active EGFR signaling and leads to activation of the MAPK/ERK pathway. Methods: A PLA developed to detect EGFR-GRB2 interaction was measured by quantitative immunofluorescence using Automated Quantitative Analysis technology. EGFR pathway activation was assessed in patients with NSCLC with different mutation status along with overall EGFR expression. Additionally, the PLA to detect EGFR-GRB2 interaction was evaluated as a prognostic marker in two cohorts of patients with lung adenocarcinoma. Results: The PLA to detect EGFR-GRB2 interaction was unrelated to overall EGFR expression or mutation in a series of patients with NSCLC with known mutation status. EGFRmutant (p = 0.04) and EGFR/KRAS wild-type tumors (p = 0.0049) had significantly higher EGFR pathway activation compared with KRAS-mutant cases, with no significant difference shown between mutation sites. In two series of patients with lung adenocarcinoma, the PLA to detect EGFR-GRB2 interaction was independently associated with longer survival (hazard ratio = 0.46, 95% confidence interval: 0.2-0.78, p = 0.0085 and hazard ratio = 0.48, 95% confidence interval: 0.2-0.85, p = 0.017). Total EGFR protein expression alone was not correlated with outcome. Conclusions: EGFR colocalization with GRB2 as assessed by PLA is not correlated with EGFR expression levels or mutation status, defining a patient group that may show EGFR pathway activation, as illustrated by its prognostic value. Future studies may determine whether this group is more likely to respond to EGFR-targeted therapies.
AB - Introduction: EGFR is a therapeutic target in NSCLC for EGFR-mutant patients. Proximity ligation assay (PLA) is a method to detect functional signaling associated protein complexes. Growth factor receptor bound protein 2 (GRB2) is an adaptor protein that binds to the phosphorylated residues of active EGFR. Interaction of EGFR and GRB2 correlates with active EGFR signaling and leads to activation of the MAPK/ERK pathway. Methods: A PLA developed to detect EGFR-GRB2 interaction was measured by quantitative immunofluorescence using Automated Quantitative Analysis technology. EGFR pathway activation was assessed in patients with NSCLC with different mutation status along with overall EGFR expression. Additionally, the PLA to detect EGFR-GRB2 interaction was evaluated as a prognostic marker in two cohorts of patients with lung adenocarcinoma. Results: The PLA to detect EGFR-GRB2 interaction was unrelated to overall EGFR expression or mutation in a series of patients with NSCLC with known mutation status. EGFRmutant (p = 0.04) and EGFR/KRAS wild-type tumors (p = 0.0049) had significantly higher EGFR pathway activation compared with KRAS-mutant cases, with no significant difference shown between mutation sites. In two series of patients with lung adenocarcinoma, the PLA to detect EGFR-GRB2 interaction was independently associated with longer survival (hazard ratio = 0.46, 95% confidence interval: 0.2-0.78, p = 0.0085 and hazard ratio = 0.48, 95% confidence interval: 0.2-0.85, p = 0.017). Total EGFR protein expression alone was not correlated with outcome. Conclusions: EGFR colocalization with GRB2 as assessed by PLA is not correlated with EGFR expression levels or mutation status, defining a patient group that may show EGFR pathway activation, as illustrated by its prognostic value. Future studies may determine whether this group is more likely to respond to EGFR-targeted therapies.
KW - Adenocarcinoma
KW - EGFR
KW - GRB2
KW - NSCLC
KW - Proximity ligation assay
KW - Quantitative immunofluorescence
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U2 - 10.1016/j.jtho.2016.06.025
DO - 10.1016/j.jtho.2016.06.025
M3 - Article
C2 - 27449805
AN - SCOPUS:84995877350
SN - 1556-0864
VL - 11
SP - 1901
EP - 1911
JO - Journal of Thoracic Oncology
JF - Journal of Thoracic Oncology
IS - 11
ER -