Effect of miR-214-3p on Cisplatin Resistance in Oral Squamous Cell Carcinoma by Regulating Ferroptosis Through...

Emerging evidence underscores the potential of ferroptosis as a promising therapeutic target in cancer. However, the role of microRNAs (miRNAs) in modulating ferroptosis sensitivity remains largely unexplored, particularly in the context of oral squamous cell carcinoma (OSCC) chemoresistance. This study was designed to investigate the role of miR-214-3p in regulating ferroptosis by targeting glutathione peroxidase 4 (GPX4) and its influence on cisplatin (DDP) resistance in OSCC.

Patients diagnosed with OSCC and receiving DDP-based chemotherapy between February 2022 and February 2024 at our institution were included in this study. Expression levels of miR-214-3p and GPX4 were quantitatively assessed in DDP-sensitive versus DDP-resistant OSCC tissues and cell lines using qRT-PCR and Western blot. Cell viability, IC50 values, and apoptosis were evaluated using the CCK-8 assay and flow cytometry. Intracellular reactive oxygen species (ROS) and Fe²⁺ levels were measured to determine the status of ferroptosis. Bioinformatics prediction and dual-luciferase reporter assays confirmed the interaction between miR-214-3p and GPX4. In vivo xenograft models were utilized to investigate the impact of miR-214-3p on OSCC tumor growth.

As an initial assessment of clinical relevance, miR-214-3p was significantly downregulated in DDP-resistant OSCC tissues and cells, whereas GPX4 expression was markedly upregulated. Overexpression of miR-214-3p substantially decreased cell viability, reduced the IC₅₀ values of DDP, and promoted apoptosis in resistant cells. In comparison to parental cells, resistant cells demonstrated lower levels of ROS and Fe²⁺. Overexpression of miR-214-3p or treatment with a ferroptosis inducer (Erastin) increased ROS and Fe²⁺ levels, an effect that was effectively reversed by a ferroptosis inhibitor (Ferrostatin-1). Bioinformatics analysis combined with luciferase reporter assays confirmed the direct binding of miR-214-3p to the 3' untranslated region (UTR) of GPX4. The overexpression of miR-214-3p resulted in the downregulation of GPX4, whereas overexpression of GPX4 reversed the effects mediated by miR-214-3p. Additionally, the overexpression of miR-214-3p in xenograft models inhibited tumor growth, which was correlated with decreased GPX4 expression and increased sensitivity to DDP.

Our findings reveal a novel miR-214-3p/GPX4/ferroptosis axis in OSCC DDP resistance. miR-214-3p suppresses GPX4 to promote ferroptosis, thereby reversing DDP resistance. This study identifies miR-214-3p as a potential therapeutic target for overcoming chemoresistance in OSCC by modulating ferroptosis.