Profile Expression and Validation of Plasma Exosomal miR-320a in Patients with Lung Adenocarcinoma as a Candidate Diagnostic Biomarker: A Study in the Indonesian Population

Lung cancer has the highest incidence rate in Indonesia, with a projected significant increase by 2040. Lung adenocarcinoma, the most common histological subtype, is often diagnosed at advanced stages due to the absence of early symptoms and reliance on invasive biopsy methods. Exosomal microRNAs (exomiRs), owing to their stability and ability to reflect tumor-specific changes, offer promise as non-invasive diagnostic biomarkers. This study aims to map the expression profile and validate exomiRs in Indonesian patients with lung adenocarcinoma so that it can be developed as a diagnostic biomarker. Plasma-derived exosomes were isolated from patients with lung adenocarcinoma and healthy controls. ExomiR profiles were first screened using NanoString analysis, followed by validation of candidate exomiRs with qRT-PCR. Differential expression was analyzed, and diagnostic performance was assessed using ROC curve analysis. The results indicate that in patients with locally advanced lung adenocarcinoma, there is upregulation of exosomal miR-320a, miR-604, miR-1261, and miR-648, as well as downregulation of exosomal miR-301b-3p, miR-605-5p, miR-924, miR-769-5p, miR-373-3p, miR-520h, miR-193a-5p, miR-3150b-3p, miR-3615, miR-4431, miR-6720-3p, miR-1909-3p, miR-574-3p, miR-382-5p, miR-593-3p, miR-572, miR-27a-3p, and miR-411-5p compared to healthy controls. In silico analysis showed that these regulated exomiRs play a role in chromatin structure formation and tumor immune cell infiltration pathways. Validation of exomiR-320a expression showed a 1.9-fold upregulation (p = 0.00032) in lung adenocarcinoma patients compared to healthy controls with an AUC value of 0.781, indicating that this miRNA has moderate potential as a diagnostic biomarker that requires further validation. © 2026, Walailak University. All rights reserved.