Identification of differentially expressed long non-coding RNAs associated with dilated cardiomyopathy using integrated bioinformatics approaches.

The aim of this study was to identify novel long non-coding RNA (lncRNA) biomarkers associated with dilated cardiomyopathy (DCM) and reveal the potential molecular mechanisms of DCM development using bioinformatics approaches. The array data of GSE5406, including 108 DCM samples and 16 non-failing control samples, were obtained from the Gene Expression Omnibus database. The differentially expressed lncRNAs were identified using limma package in R. Pearson's correlation analyses were performed between the differentially expressed lncRNAs and protein-coding genes based on their expression levels. Pathway enrichment of these lncRNAs was conducted based on the significantly co-expressed genes. From the receiver operating characteristic (ROC) curve, the area under the ROC curve (AUC) value was obtained and used for evaluating discriminatory ability. IDI2-AS1 and XIST were differentially expressed in DCM patients. A total of 510 co-expressed genes were identified. The enriched functions and pathways of the co-expressed genes mainly included NADH dehydrogenase activity, cardiac muscle contraction, and oxidative phosphorylation. The ROC curve analysis indicated that the two lncRNAs have favorable diagnostic values in DCM. The AUC values of XIST, IDI2-AS1, and the combination of XIST and IDI2-AS1 were 0.733 (95% CI: 0.646-0.809), 0.796 (95% CI: 0.715-0.863), and 0.823 (95% CI: 0.745-0.886), respectively. This study identified IDI2-AS1 and XIST lncRNAs and related pathways involved in the pathogenesis of DCM, thus providing potential diagnostic and therapeutic targets for DCM.