qPCR, Western blot, Luciferase reporter assay, Other
plasma, NLCLC tissues and cell lines (A549, NCI-H460, NCI-H1299 and NCI-H358)
EGFR-AS1 was abnormally upregulated in NSCLC tissues compared with adjacent normal lung tissues. Furthermore, patients with NSCLC with increased expression of EGFR-AS1 had a poor prognosis. EGFR-AS1 knockdown significantly inhibited NSCLC malignancy in vitro, including cell proliferation and chemoresistance. Furthermore, the expression levels of EGFR-AS1 were increased in plasma samples from patients with cisplatin-based chemotherapy resistance. Bioinformatics analysis and a luciferase reporter assay confirmed that EGFR-AS1 mediated cell proliferation and chemoresistance through directly binding to microRNA-223. Therefore, EGFR-AS1 overexpression-induced chemoresistance can contribute to poor prognosis in NSCLC.