title: CRIPTO1 expression in EGFR-mutant NSCLC elicits intrinsic EGFR-inhibitor resistance.
abstract: The majority of non-small cell lung cancer (NSCLC) patients harbor EGFR-activating mutations that can be therapeutically targeted by EGFR tyrosine kinase inhibitors (EGFR-TKI), such as erlotinib and gefitinib. Unfortunately, a subset of patients with EGFR mutations are refractory to EGFR-TKIs. Resistance to EGFR inhibitors reportedly involves SRC activation and induction of epithelial-to-mesenchymal transition (EMT). Here, we have demonstrated that overexpression of CRIPTO1, an EGF-CFC protein family member, renders EGFR-TKI-sensitive and EGFR-mutated NSCLC cells resistant to erlotinib in culture and in murine xenograft models. Furthermore, tumors from NSCLC patients with EGFR-activating mutations that were intrinsically resistant to EGFR-TKIs expressed higher levels of CRIPTO1 compared with tumors from patients that were sensitive to EGFR-TKIs. Primary NSCLC cells derived from a patient with EGFR-mutated NSCLC that was intrinsically erlotinib resistant were CRIPTO1 positive, but gained erlotinib sensitivity upon loss of CRIPTO1 expression during culture. CRIPTO1 activated SRC and ZEB1 to promote EMT via microRNA-205 (miR-205) downregulation. While miR-205 depletion induced erlotinib resistance, miR-205 overexpression inhibited CRIPTO1-dependent ZEB1 and SRC activation, restoring erlotinib sensitivity. CRIPTO1-induced erlotinib resistance was directly mediated through SRC but not ZEB1; therefore, cotargeting EGFR and SRC synergistically attenuated growth of erlotinib-resistant, CRIPTO1-positive, EGFR-mutated NSCLC cells in vitro and in vivo, suggesting that this combination may overcome intrinsic EGFR-inhibitor resistance in patients with CRIPTO1-positive, EGFR-mutated NSCLC.
authors.forename: Kang-Seo
authors.initials: KS
authors.lastname: Park
authors.forename: Mark
authors.initials: M
authors.lastname: Raffeld
authors.forename: Yong Wha
authors.initials: YW
authors.lastname: Moon
authors.forename: Liqiang
authors.initials: L
authors.lastname: Xi
authors.forename: Caterina
authors.initials: C
authors.lastname: Bianco
authors.forename: Trung
authors.initials: T
authors.lastname: Pham
authors.forename: Liam C
authors.initials: LC
authors.lastname: Lee
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Mitsudomi
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Yatabe
authors.forename: Isamu
authors.initials: I
authors.lastname: Okamoto
authors.forename: Deepa
authors.initials: D
authors.lastname: Subramaniam
authors.forename: Tony
authors.initials: T
authors.lastname: Mok
authors.forename: Rafael
authors.initials: R
authors.lastname: Rosell
authors.forename: Ji
authors.initials: J
authors.lastname: Luo
authors.forename: David S
authors.initials: DS
authors.lastname: Salomon
authors.forename: Yisong
authors.initials: Y
authors.lastname: Wang
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Giaccone
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology; D002289:Carcinoma, Non-Small-Cell Lung / Q000188:drug therapy* / Q000235:genetics* / Q000378:metabolism; D045744:Cell Line, Tumor; D019008:Drug Resistance, Neoplasm / Q000235:genetics; D058750:Epithelial-Mesenchymal Transition; D066246:ErbB Receptors / Q000037:antagonists & inhibitors* / Q000235:genetics*; D000069347:Erlotinib Hydrochloride; D058851:GPI-Linked Proteins / Q000235:genetics* / Q000378:metabolism; D000077156:Gefitinib; D018773:Genes, erbB-1; D018398:Homeodomain Proteins / Q000378:metabolism; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins / Q000235:genetics* / Q000378:metabolism; D008175:Lung Neoplasms / Q000188:drug therapy* / Q000235:genetics* / Q000378:metabolism; D051379:Mice; D008819:Mice, Nude; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism; D009154:Mutation; D009363:Neoplasm Proteins / Q000235:genetics* / Q000378:metabolism; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D011799:Quinazolines / Q000494:pharmacology; D014157:Transcription Factors / Q000378:metabolism; D023041:Xenograft Model Antitumor Assays; D000071799:Zinc Finger E-box-Binding Homeobox 1; D019061:src-Family Kinases / Q000378:metabolism
chemical_list: D000970:Antineoplastic Agents; D066246:ErbB Receptors; D000069347:Erlotinib Hydrochloride; D058851:GPI-Linked Proteins; D000077156:Gefitinib; D018398:Homeodomain Proteins; D036341:Intercellular Signaling Peptides and Proteins; D035683:MicroRNAs; D009363:Neoplasm Proteins; D047428:Protein Kinase Inhibitors; D011799:Quinazolines; D014157:Transcription Factors; D000071799:Zinc Finger E-box-Binding Homeobox 1; D019061:src-Family Kinases; C534425:MIR205, human; C070636:TDGF1 protein, human; C486307:ZEB1 protein, human; C512478:EGFR protein, human