Role of miR-1 and its potential regulation of signaling pathways in bladder cancer: a comprehensive investigation based on TCGA, GEO, ArrayExpress, and bioinformatics analysis

Objective: To determine miR-1 expression and its potential molecular mechanism in bladder cancer. Methods: We analyzed the correlation between miR-1 expression and different clinicopathological features based on The Cancer Genome Atlas (TCGA). Gene Expression Omnibus (GEO) and ArrayExpress microarray datasets, as well as data from TCGA and the literature, were used to explore miR-1 expression in bladder cancer. A fixed-effects model and a random-effects model were used. We detected the diagnostic value of miR-1 in bladder cancer. Differentially expressed genes in TCGA, genes from predicting tools and upregulated genes in GSE24782 were then cross-referenced. The target genes from the literature were added, and the final genes were considered the promising target genes of miR-1 in bladder cancer. Subsequently, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were carried out. Results: The combined standardized mean difference was -1.29 (95% CI: -1.57, -2.00) and -1.83 (95% CI: -3.08, -0.58) based on the fixed-and random-effects models, respectively. The area under the curve was 0.9660 (Q* = 0.9135) in the summarized receiver operating characteristic curve. The most significantly related GO annotation items were blood vessel development in biological processes, extracellular region in cellular components, and G-protein-activated inward-rectifier potassium channel activity in molecular functions. KEGG pathway analysis demonstrated that the promising target genes of miR-1 in bladder cancer were related to maturity onset diabetes of the young. Conclusion: The miR-1 was downregulated in bladder cancer. It might play an important role via its target genes in bladder cancer.