High expression of SLC34A2 contributes to chemoresistance of non-small cell lung cancer against gefitinib: The critical role of miR-124-3p.

Gefitinib is a therapeutic agent used to treat lung carcinoma, including non-small cell lung cancer (NSCLC). However, mechanisms underlying NSCLC cell resistance to gefitinib remain largely uncharacterized. In this study, we explored the association between the miR-124-3p/SLC34A2 axis and gefitinib resistance using a series of in vivo and in vitro assays. Data indicated that miR-124-3p is downregulated, while SLC34A2 is upregulated, in gefitinib-resistant NSCLC cells. Overexpression of miR-124-3p reduced NSCLC cell resistance to gefitinib by suppressing cell viability, inducing apoptosis, and decreasing N-cadherin expression. Conversely, inhibiting miR-124-3p in NSCLC cells led to increased cell viability and reduced apoptosis. Overexpression of SLC34A2 in NSCLC cells further heightened gefitinib resistance. In a xenograft mouse model, SLC34A2 overexpression promoted solid tumor growth and metastasis, while miR-124-3p overexpression inhibited these effects. Our results highlight that the interaction between miR-124-3p and SLC34A2 plays an indispensable role in determining gefitinib resistance in NSCLC cells.