Biomarker identification in clear cell renal cell carcinoma based on miRNA-seq and digital gene expression-seq data

This study aimed to explore the underlying microRNA (miRNA) targets in clear cell renal cell carcinoma (ccRCC). The expression profile with accession number GSE24952 was downloaded from the Gene Expression Omnibus database. Based on the dataset, the differentially expressed genes (DEGs) and miRNAs in ccRCC tissues and matched normal adjacent tissues were analyzed. The target genes of the differentially expressed miRNAs were then predicted. Expression levels of several key miRNAs and genes were detected by quantitative reverse transcription polymerase chain reaction (qRT-PCR). A total of 168 up- and 288 downregulated DEGs, and 26 up- and 54 downregulated differentially expressed miRNAs were identified. The target genes of miRNA-429 (TGFB1, CCND1, EGFR, and LAMC1) and miRNA-206 (CCND1 and EGFR) were upregulated. Based on the tumor suppressor (TS) gene and tumor-associated gene (TAG) databases, miRNA-142-5p was selected from the upregulated miRNAs. miRNA-429, miRNA-422a, miRNA-206, miRNA-132-3p, and miRNA-184 were selected from the downregulated miRNAs. Moreover, the miRNA regulation network revealed that CCND1 was the common target gene of miRNA-429, miRNA-206, and miRNA-184, and ATP1B1 was the common target gene of miRNA-140-3p and miRNA-142-5p. qRT-PCR revealed that the expression levels of miR-140-3p and CCND1 significantly increased, while that of ATP1B1 significantly decreased in 786-O cells compared with those in human renal tubular epithelial cells, which was in accordance with the predicted results of bioinformatic analysis. In conclusion, miRNA-429, miRNA-206, and miRNA-184 and their target gene CCND1, as well as miRNA-140-3p and miRNA-142-5p and their target gene ATP1B1, might play key roles in ccRCC progression and could be useful biomarkers during ccRCC development.