hsa_circ_0000729, a potential prognostic biomarker in lung adenocarcinoma.

Background: Increasing evidence has demonstrated that circular RNAs (circRNAs) may play an important role in oncogenesis and tumor development; however, their role in lung adenocarcinoma (LUAD) remains unclear. We identified the differentially expressed circRNAs in LUAD and investigated the potential mechanisms for cancer progression.

Methods: We examined differentially expressed circRNAs in LUAD and paired normal tissues using downloaded circRNA microarrays from the Gene Expression Omnibus. We constructed gene co-expression networks based on the degree of Pearson correlation to predict the critical circRNA in LUAD. Gene Ontology analysis was performed on the genes in the network. We observed one novel circRNA upregulated in LUAD, hsa_circ_0000792, as well as its potential sponged microRNA, miR-375. Subsequent real-time quantitative PCR was used to verify the bioinformatics analysis.

Results: Several circRNAs showed significantly different expression levels in LUAD tissues. Real-time quantitative PCR and further co-expression network analysis of 42 matched tissue samples showed a significant difference in expression between LUAD and normal tissues in hsa_circ_0000792 (P < 0.001). We built a network of hsa_circ_0000792-targeted miRNA gene interactions, including miR-375 and the corresponding messenger RNAs. Gene Ontology analysis revealed that hsa_circ_0000792 could participate in signal transduction and cell communication during LUAD development. Larger area under the curve by receiver operating characteristic curve analysis of hsa_circ_0000792 and miR-375 (0.815 and 0.772, respectively) in LUAD indicated greater potential as biomarkers.

Conclusions: We identified hsa_circ_0000792 as a potential LUAD biomarker; however, further studies are required to determine the mechanism of this circRNA in LUAD development.