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Aim To investigate the role of auranofin in reversing acquired resistance to osimertinib in non-small cell lung cancer. Methods Osimertinib-sensi-tive NSCLC cell lines HI975 and PC9 were used to establish osimertinib-resistant NSCLC cell lines HI975/OR and PC9/OR. An FDA approved library of 1470 FDA drugs was used to high-throughput screen the reversal agents of acquired resistant of osimertinib by CCK-8. Compusyn was used to calculate the combination index of osimertinib and auranofin to determine the optimal dose of drug combination. CCK-8, EdU, flow cytometry and Transwell experiments were used to detect osimertinib, auranofin and the combination drug effect on proliferation, apoptosis, migration and invasion of osimertinib acquired NSCLC cell lines. RNA-sequencing was applied to screen differentially expressed mRNAs in osimertinib treatment alone and osimertinib combined with auranofin treatment group. qRT-PCR and western blot were employed to validate the selected gene expression and protein expression. Results Compared with osimertinib sensitive cell lines H1975 and PC9, H1975/OR and PC9/OR showed significantly higher cell viability and lower apoptosis rate after osimertinib treatment. The resistance index was 70. 31 and 136. 99, respectively. In FDA approved 1470 drug library, only auranofin could enhance the sensitivity of osimertinib in H1975/OR and PC9/OR. When 1 μmol • L
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OBJECTIVE@#To screen the differentially expressed long non-coding RNAs (lncRNAs) in non-small cell lung cancer (NSCLC) cells with acquired resistance to osimertinib and explore their roles in drug resistance of the cells.@*METHODS@#The cell lines H1975_OR and HCC827_OR with acquired osimertinib resistance were derived from their osimertinib-sensitive parental NSCLC cell lines H1975 and HCC827, respectively, and their sensitivity to osimertinib was assessed with CCK-8 assay, clone formation assay and flow cytometry. RNA sequencing (RNA-seq) and real-time quantitative PCR (qPCR) were used to screen the differentially expressed lncRNAs in osimertinib-resistant cells. The role of the identified lncRNA in osimertinib resistance was explored using CCK-8, clone formation and Transwell assays, and its subcellular localization and downstream targets were analyzed by nucleoplasmic separation, bioinformatics analysis and qPCR.@*RESULTS@#The resistance index of H1975_OR and HCC827_OR cells to osimertinib was 598.70 and 428.82, respectively (P < 0.001), and the two cell lines showed significantly increased proliferation and colony-forming abilities with decreased apoptosis (P < 0.01). RNA-seq identified 34 differentially expressed lncRNAs in osimertinib-resistant cells, and among them lnc-TMEM132D-AS1 showed the highest increase of expression after acquired osimertinib resistance (P < 0.01). Analysis of the TCGA database suggested that the level of lnc-TMEM132D-AS1 was significantly higher in NSCLC than in adjacent tissues (P < 0.001), and its high expression was associated with a poor prognosis of the patients. In osimertinib-sensitive cells, overexpression of Lnc-TMEM132D-AS1 obviously promoted cell proliferation, colony formation and migration (P < 0.05), while Lnc-TMEM132D-AS1 knockdown partially restored osimertinib sensitivity of the resistant cells (P < 0.01). Lnc-TMEM132D-AS1 was localized mainly in the cytoplasm, and bioinformatics analysis suggested that hsa-miR-766-5p was its candidate target, and their expression levels were inversely correlated. The target mRNAs of hsa-miR-766-5p were mainly enriched in the Ras signaling pathway.@*CONCLUSION@#The expression of lnc-TMEM132D-AS1 is significantly upregulated in NSCLC cells with acquired osimertinib resistance, and may serve as a potential biomarker and therapeutic target for osimertinibresistant NSCLC.