MiR-200a-5p Is a Potential Prognostic Marker for Lung Adenocarcinoma: Based on Transcriptomics, Bioinformatics, and In Vitro and In Vivo Experiments

Lung adenocarcinoma is a prevalent cancer worldwide. MicroRNAs (miRNAs) are key regulators in various cancers, with miR-200a-5p emerging as a potential candidate due to its possible role in lung adenocarcinoma. However, its exact mechanisms of action remain unclear. We performed transcriptome sequencing of 32 clinical pairs to identify differentially expressed miRNAs. miR-200a-5p expression was validated in tissues and cell lines (H1975, A549) using bioinformatics and RT-qPCR. Biological effects were assessed via CCK8, EdU, Transwell, scratch assays, flow cytometry, and Western blotting (phosphorylated transducer and activator of transcription 3, fibronectin, matrix metallopeptidase 9, proliferating cell nuclear antigen, and Wnt pathway-related proteins). A protein-protein interaction network predicted downstream targets, focusing on the Wnt pathway. In vivo experiments, immunohistochemistry, and Western blotting evaluated tumour growth and Ki-67/Wnt protein expression. We found that miR-200a-5p was significantly up-regulated in lung adenocarcinoma tissues and cells, correlating with poor prognosis. Up-regulation enhanced proliferation, migration and invasion while inhibiting apoptosis in vitro. Down-regulation produced opposite effects. In vivo, miR-200a-5p promoted tumour growth via Wnt pathway activation. We conclude that miR-200a-5p acts as an oncogenic factor in lung adenocarcinoma by facilitating progression through the Wnt pathway. These findings suggest its potential as a therapeutic target and prognostic biomarker.