Alexandria Engineering Journal (Oct 2023)
Experimental and clinical validation of diagnostic and prognostic biomarkers identified by integrated study of microRNA and mRNA expression patterns in lung cancer
Abstract
Lung cancer remains a leading cause of cancer-related mortality worldwide, with a complex molecular pathogenesis that is still not fully understood. Given the challenging task of distinguishing between subtypes of lung cancer (LUAD and LUSC), this study aimed to evaluate the potential of microRNAs (miRNAs) as biomarkers for differentiating these subtypes, by leveraging cancer genomics data. We used bioinformatics analysis for miRNA target prediction. In this regard, a miRNA-mRNA interaction network was defined and pathway analysis was subsequently established. To verify the results of the bioinformatic analysis, we conducted clinical and pre-clinical experiments. We carried out survival analysis, comparing gene expression and mortality rates between two major subtypes of lung cancer, LUSC and LUAD, from 45 lung cancer patients. Additionally, in vitro and in vivo studies were performed using human lung cancer cell lines to alter the expression of miR-21 and miR-326 using plasmid models. Finally, we conducted numerous assays to evaluate cell viability, cell migration and invasion, apoptosis, and cell cycle detection. We observed 102 miRNAs and 1,974 mRNAs as having differential expression in LUAD, whereas 143 miRNAs and 2,821 mRNAs were shown to have such an effect in LUSC. We found that hsa-mir-375 might significantly distinguish LUAD from LUSC, and our clinical validation demonstrated that the level of hsa-mir-375 was significantly higher in LUAD than in LUSC. In terms of finding a diagnostic marker, we discovered that a high level of hsa-mir-21 and/or hsa-mir-326 correlated with a worse prognosis. Our subsequent pre-clinical experiment showed that high expression of hsa-mir-21 and/or hsa-mir-326 significantly increased the aggressiveness of lung cancer and that inhibition of these miRNAs could potentially decrease the tumorigenic behavior of lung cancer cell lines. In conclusion, hsa-mir-21 and hsa-mir-326 might be potential diagnostic biomarkers for lung cancer and hsa-mir-375 might be a potential LUAD and LUSC distinguishing biomarker.
