LINC01446/miR-338-3p/APEX1 Axis Promotes Ferroptosis Defense and Progression in Esophageal Squamous Cell Carcinoma.

BACKGROUND

Esophageal squamous cell carcinoma (ESCC) is an aggressive malignancy with a poor prognosis, highlighting the urgent need to elucidate its molecular mechanisms to develop targeted therapies. Long non-coding RNAs (lncRNAs) play a critical role in cancer progression. However, the majority of lncRNAs involved in ESCC progression remain to be elucidated.

METHODS

We integrated bioinformatic analyses of the TCGA and GEO datasets to identify differentially expressed lncRNAs in ESCC, and the biological functions of the candidate lncRNA LINC01446 were investigated using loss-of-function assays in ESCC cell lines, including colony formation, wound healing, Transwell invasion, C11-BODIPY staining, malondialdehyde (MDA) quantification, and glutathione (GSH) evaluation. A nude mouse xenograft model was established for in vivo validation, and the underlying molecular mechanism was explored through RNA sequencing, fluorescence in situ hybridization (FISH), dual-luciferase reporter assays, AGO2-RIP, and rescue experiments.

RESULTS

LINC01446 was significantly upregulated in ESCC tissues and cell lines. Based on univariate analysis, high expression of LINC01446 was associated with poorer overall survival (OS). Functional studies showed that LINC01446 knockdown suppressed ESCC cell proliferation, migration, and invasion, promoted ferroptosis-related changes in vitro and was associated with increased lipid peroxidation and possible ferroptosis-related changes in vivo. Mechanistic analyses supported a regulatory relationship in which LINC01446 may function as a competing endogenous RNA (ceRNA) for miR-338-3p, thereby contributing to the upregulation of its downstream target, apurinic/apyrimidinic endodeoxyribonuclease 1 (APEX1), in ESCC cells. Moreover, APEX1 was found to be overexpressed in ESCC and associated with poor OS.

CONCLUSIONS

This study suggests that the LINC01446/miR-338-3p/APEX1 regulatory axis may contribute to ESCC progression and ferroptosis-related regulation. Additionally, LINC01446 and APEX1 represent promising prognostic biomarkers and therapeutic targets for ESCC.