Elevated expression of Fn14 in non-small cell lung cancer correlates with activated EGFR and promotes tumor cell migration and invasion.
Lung cancer is the leading cause of cancer deaths worldwide; approximately 85% of these cancers are non-small cell lung cancer (NSCLC). Patients with NSCLC frequently have tumors harboring somatic mutations in the epidermal growth factor receptor (EGFR) gene that cause constitutive receptor activation. These patients have the best clinical response to EGFR tyrosine kinase inhibitors (TKIs). Herein, we show that fibroblast growth factor-inducible 14 (Fn14; TNFRSF12A) is frequently overexpressed in NSCLC tumors, and Fn14 levels correlate with p-EGFR expression. We also report that NSCLC cell lines that contain EGFR-activating mutations show high levels of Fn14 protein expression. EGFR TKI treatment of EGFR-mutant HCC827 cells decreased Fn14 protein levels, whereas EGF stimulation of EGFR wild-type A549 cells transiently increased Fn14 expression. Furthermore, Fn14 is highly expressed in EGFR-mutant H1975 cells that also contain an EGFR TKI-resistance mutation, and high TKI doses are necessary to reduce Fn14 levels. Constructs encoding EGFRs with activating mutations induced Fn14 expression when expressed in rat lung epithelial cells. We also report that short hairpin RNA-mediated Fn14 knockdown reduced NSCLC cell migration and invasion in vitro. Finally, Fn14 overexpression enhanced NSCLC cell migration and invasion in vitro and increased experimental lung metastases in vivo. Thus, Fn14 may be a novel therapeutic target for patients with NSCLC, in particular for those with EGFR-driven tumors who have either primary or acquired resistance to EGFR TKIs.
Division of Cancer and Cell Biology, The Translational Genomics Research Institute, Phoenix, AZ 85004, USA.
Timothy G
TG
Whitsett
Emily
E
Cheng
Landon
L
Inge
Kaushal
K
Asrani
Nathan M
NM
Jameson
Galen
G
Hostetter
Glen J
GJ
Weiss
Christopher B
CB
Kingsley
Joseph C
JC
Loftus
Ross
R
Bremner
Nhan L
NL
Tran
Jeffrey A
JA
Winkles
D000818:Animals; D002289:Carcinoma, Non-Small-Cell Lung / Q000235:genetics / Q000378:metabolism* / Q000473:pathology / Q000556:secondary; D002465:Cell Movement / Q000502:physiology; D066246:ErbB Receptors / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D000069347:Erlotinib Hydrochloride; D055785:Gene Knockdown Techniques; D011905:Genes, ras / Q000235:genetics; D006801:Humans; D008175:Lung Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D051379:Mice; D016513:Mice, SCID; D009154:Mutation; D009361:Neoplasm Invasiveness; D009363:Neoplasm Proteins / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology; D009368:Neoplasm Transplantation; D010766:Phosphorylation; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D011799:Quinazolines / Q000494:pharmacology; D051381:Rats; D018124:Receptors, Tumor Necrosis Factor / Q000096:biosynthesis / Q000172:deficiency / Q000235:genetics / Q000502:physiology*; D015398:Signal Transduction / Q000502:physiology; D000074050:TWEAK Receptor; D014407:Tumor Cells, Cultured
D009363:Neoplasm Proteins; D047428:Protein Kinase Inhibitors; D011799:Quinazolines; D018124:Receptors, Tumor Necrosis Factor; C000613297:TNFRSF12A protein, human; D000074050:TWEAK Receptor; C000613299:Tnfrsf12a protein, mouse; C000613300:Tnfrsf12a protein, rat; D000069347:Erlotinib Hydrochloride; D066246:ErbB Receptors