Long Noncoding RNA LINC01116 Contributes to Gefitinib Resistance in Non-small Cell Lung Cancer through Regulating IFI44

Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs), such as gefitinib, have been established as first-line treatments for non-small cell lung cancer (NSCLC) patients and have exhibited notable clinical efficacy. However, resistance to TKIs has become one of the major obstacles in improving the therapeutic efficacy of patients with NSCLC. This study aims to investigate the role of the long non-coding RNA (lncRNA) LINC01116 in gefitinib resistance of NSCLC and explore its underlying mechanism. In this study, we found that LINC01116 is upregulated in the gefitinib-resistant NSCLC cells and tissues. Loss- and gain-of-function assays uncovered that LINC01116 downregulation sensitized gefitinib resistance, whereas the overexpression of LINC01116 conferred PC9/R cells to gefitinib treatment. Moreover, LINC01116 silencing increased IFI44 expression. Overexpression of IFI44 reversed the resistance to gefitinib in PC9/R cells, and rescue experiments confirmed that LINC01116 affects the gefitinib resistance of PC9/R cells partly dependent on regulating IFI44 expression. Moreover, downregulation of LINC01116 increased the sensitivity of PC9/R cells to gefitinib in vivo. Our study demonstrates that LINC01116 plays a critical role in gefitinib resistance of NSCLC cells by affecting IFI44 expression, providing a novel therapeutic target to overcome TKI resistance in NSCLC.