Molecular Mechanism of microRNA-429 Targeting HMOX1 to Regulate Invasion, Migration, and Ferroptosis in Lung Adenocarcinoma Cells

Objective To investigate the effects of microRNA-429 (miR-429) on the invasion, migration, and ferroptosis of lung adenocarcinoma (LUAD) cells, and to provide new insights into the clinical inhibition of LUAD invasion and migration and the promotion of ferroptosis.

Methods The expression profile of miR-429 in LUAD tissues was analyzed using the starBase database. Quantitative real-time PCR (qRT-PCR) was performed to assess miR-429 expression levels in normal human bronchial epithelial cells (the BEAS-2B cell line) and LUAD cells (the A549 and H1975 cell lines), and to evaluate the plasmid transfection efficiency. The effects of miR-429 on A549 cell proliferation, migration, and invasion were assessed using 5-ethynyl-2^'-deoxyuridine (EdU) incorporation assay, scratch wound healing assay, and Transwell invasion assay, respectively. Potential ferroptosis-related proteins targeted by miR-429 were predicted using bioinformatics databases, and the targeting relationship between miR-429 and heme oxygenase 1 (HMOX1) was validated by a dual-luciferase reporter assay. Further functional experiments were performed to examine the effect of miR-429 targeting HMOX1 on the malignant phenotypes of A549 cells. The levels of reactive oxygen species (ROS) and lipid ROS (L-ROS) were measured to analyze the regulatory effects of miR-429 and HMOX1 on oxidative stress in LUAD cells. The contents of malondialdehyde (MDA), glutathione (GSH), and ferrous ion (Fe²⁺) were measured to evaluate evaluate the effects of miR-429 and HMOX1 on key ferroptosis-associated indicators in LUAD cells.

Results miR-429 expression was significantly higher in LUAD cell lines (A549 and H1975) compared with that in normal cells (BEAS-2B), with the highest expression level observed in A549 cells. Functional experiments demonstrated that miR-429 promoted A549 cell proliferation, migration, and invasion. The dual-luciferase assay confirmed that miR-429 directly targeted HMOX1, and their expression levels were negatively correlated in LUAD cells. HMOX1 overexpression inhibited the proliferation, invasion, and migration of A549 cells, while miR-429 overexpression reversed these inhibitory effects. Mechanistically, miR-429 targeted and inhibited HMOX1, which led to reduced intracellular levels of ROS, L-ROS, MDA, and Fe²⁺ and increased GSH levels in A549 cells, thereby decreasing cellular sensitivity to ferroptosis.

Conclusion miR-429 promotes the invasion and migration of LUAD cells and inhibits ferroptosis by targeting and inhibiting HMOX1.