Intratumoral Heterogeneity in EGFR-Mutant NSCLC Results in Divergent Resistance Mechanisms in Response to EGFR Tyrosine Kinase Inhibition.
Non-small cell lung cancers (NSCLC) that have developed resistance to EGF receptor (EGFR) tyrosine kinase inhibitor (TKI), including gefitinib and erlotinib, are clinically linked to an epithelial-to-mesenchymal transition (EMT) phenotype. Here, we examined whether modulating EMT maintains the responsiveness of EGFR-mutated NSCLCs to EGFR TKI therapy. Using human NSCLC cell lines harboring mutated EGFR and a transgenic mouse model of lung cancer driven by mutant EGFR (EGFR-Del19-T790M), we demonstrate that EGFR inhibition induces TGFβ secretion followed by SMAD pathway activation, an event that promotes EMT. Chronic exposure of EGFR-mutated NSCLC cells to TGFβ was sufficient to induce EMT and resistance to EGFR TKI treatment. Furthermore, NSCLC HCC4006 cells with acquired resistance to gefitinib were characterized by a mesenchymal phenotype and displayed a higher prevalence of the EGFR T790M mutated allele. Notably, combined inhibition of EGFR and the TGFβ receptor in HCC4006 cells prevented EMT but was not sufficient to prevent acquired gefitinib resistance because of an increased emergence of the EGFR T790M allele compared with cells treated with gefitinib alone. Conversely, another independent NSCLC cell line, PC9, reproducibly developed EGFR T790M mutations as the primary mechanism underlying EGFR TKI resistance, even though the prevalence of the mutant allele was lower than that in HCC4006 cells. Thus, our findings underscore heterogeneity within NSCLC cells lines harboring EGFR kinase domain mutations that give rise to divergent resistance mechanisms in response to treatment and anticipate the complexity of EMT suppression as a therapeutic strategy.
Department of Molecular Pharmacology and Therapeutics, Oncology Research Institute, Loyola University Chicago, Stritch School of Medicine, Maywood, Illinois.
Margaret
M
Soucheray
Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts. Belfer Institute for Applied Cancer Science, Dana-Farber Cancer Institute, Boston, Massachusetts. Lowe Center for Thoracic Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts.
Marzia
M
Capelletti
Departament de Fisiologia, Facultat de Farmacia, Universitat de Valencia, Burjassot, Spain.
Inés
I
Pulido
Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts. Belfer Institute for Applied Cancer Science, Dana-Farber Cancer Institute, Boston, Massachusetts.
Yanan
Y
Kuang
Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts. Belfer Institute for Applied Cancer Science, Dana-Farber Cancer Institute, Boston, Massachusetts.
Cloud P
CP
Paweletz
Department of Molecular Pharmacology and Therapeutics, Oncology Research Institute, Loyola University Chicago, Stritch School of Medicine, Maywood, Illinois.
Jeffrey H
JH
Becker
First department of Medicine, Hokkaido University Hospital, Sapporo, Hokkaido, Japan.
Eiki
E
Kikuchi
Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts.
Chunxiao
C
Xu
Department of Molecular Pharmacology and Therapeutics, Oncology Research Institute, Loyola University Chicago, Stritch School of Medicine, Maywood, Illinois.
Tarun B
TB
Patel
Translational Bioinformatics Unit, Clinical Research Programme, Spanish National Cancer Research Centre, Madrid, Spain.
Fatima
F
Al-Shahrour
Departament de Fisiologia, Facultat de Farmacia, Universitat de Valencia, Burjassot, Spain.
Julián
J
Carretero
Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts. Belfer Institute for Applied Cancer Science, Dana-Farber Cancer Institute, Boston, Massachusetts. Lowe Center for Thoracic Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts. Ludwig Center at Dana-Farber/Harvard Cancer Center, Dana-Farber Cancer Institute, Boston, Massachusetts.
Kwok-Kin
KK
Wong
Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts. Belfer Institute for Applied Cancer Science, Dana-Farber Cancer Institute, Boston, Massachusetts. Lowe Center for Thoracic Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts.
Pasi A
PA
Jänne
Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts. Early Drug Development Center; Dana-Farber Cancer Institute, Boston, Massachusetts.
Geoffrey I
GI
Shapiro
Department of Molecular Pharmacology and Therapeutics, Oncology Research Institute, Loyola University Chicago, Stritch School of Medicine, Maywood, Illinois. tashimamura@luc.edu.
Takeshi
T
Shimamura
D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology*; D002289:Carcinoma, Non-Small-Cell Lung / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D045744:Cell Line, Tumor; D016000:Cluster Analysis; D019008:Drug Resistance, Neoplasm / Q000235:genetics*; D058750:Epithelial-Mesenchymal Transition / Q000187:drug effects / Q000235:genetics; D000077156:Gefitinib; D020869:Gene Expression Profiling; D006801:Humans; D008175:Lung Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D051379:Mice; D009154:Mutation; D010641:Phenotype; D047428:Protein Kinase Inhibitors / Q000494:pharmacology*; D011799:Quinazolines / Q000494:pharmacology; D018125:Receptors, Transforming Growth Factor beta / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D051785:Smad Proteins / Q000378:metabolism; D053773:Transforming Growth Factor beta1 / Q000378:metabolism / Q000494:pharmacology
D000970:Antineoplastic Agents; D047428:Protein Kinase Inhibitors; D011799:Quinazolines; D018125:Receptors, Transforming Growth Factor beta; D051785:Smad Proteins; D053773:Transforming Growth Factor beta1; D000077156:Gefitinib