Long non-coding RNA prostate cancer-associated transcript 6 inhibited gefitinib sensitivity of non-small cell lung cancer by serving as a competing endogenous RNA of miR-326 to up-regulate interferon-alpha receptor 2

The critical roles of lncRNAs in drug resistance of malignancies have been widely recognized. This investigation aims to study the function of lncRNA PCAT6 in the resistance of non-small cell lung cancer (NSCLC) to gefitinib. In our study, we demonstrated that prostate cancer-associated transcript 6 (PCAT6) was upregulated in gefitinib-resistant NSCLC. PCAT6 knockdown inhibited gefitinib resistance of NSCLC, as indicated by decreased IC(50) value, proliferation, and metastasis, and increased cell apoptosis. Besides, PCAT6 could directly target miR-326 in gefitinib-resistant NSCLC cells and augment NSCLC resistance to gefitinib by serving as ceRNA of miR-326. Furthermore, interferon-alpha receptor 2 (IFNAR2) was validated as a downstream target of miR-326 and miR-326 reduced resistance to gefitinib by inhibiting IFNAR2 expression. Our investigation identified that PCAT6 enhanced gefitinib resistance of NSCLC via miR-326/IFNAR2 axis, which might offer a new therapeutic strategy against gefitinib resistance of NSCLC patients.