Abstract
BACKGROUND: For lung adenocarcinoma (LUAD), the competitive endogenous RNA (ceRNA) networks mediated by circular RNAs (circRNAs) have been partially constructed. However, a mass of networks still need to be thoroughly investigated to uncover novel regulatory axes in LUAD. METHODS: Clinical information along with transcriptome data were obtained from open databases. The circRNA-mediated ceRNA subnetworks and a risk score were constructed through layer-by-layer screening and validating. Immune infiltration analysis was performed by CIBERSORT. Quantitative real-time PCR, immunohistochemical analysis, and dual-luciferase reporter assays confirmed the expression and relationships of hub genes. RESULTS: The expression of 9 circRNAs, 81 miRNAs, and 952 mRNAs significantly varied in LUAD tissues. Subsequently, 63 miRNA-mRNA interactions and 3 circRNA-miRNA interactions were employed to generate a ceRNA network. Two prognostic subnetworks mediated by hsa_circ_0072088 and hsa_circ_0049271 were obtained following hub genes screening and survival analysis. Then, a risk score consisting of MMP14 and DCN was successfully constructed and verified using a different dataset. Among the high-risk group, more deaths and poor prognosis occurred. The distribution of immune infiltrating cells varied between high- and low-risk groups, and they were correlated with both the expression of DCN and MMP14 and the risk score. CONCLUSIONS: The two key regulatory axes, hsa_circ_0072088/hsa-miR-532-3p/MMP14 and hsa_circ_0049271/hsa-miR-224-5p/DCN, might be involved in carcinogenesis, prognosis and immune infiltration of LUAD.