Screening and Bioinformatics Analysis of MicroRNA Biomarkers in Triple-Negative Breast Cancer

<b>Objective:</b> To identify and evaluate the bioinformatics of microRNA (miRNA) biomarkers in triple-negative breast cancer. <b>Methods:</b> The MDA-MB-231 cell line with stable and low expression of c-Myc was created, and the expression patterns of messenger RNA (mRNA) and miRNA were investigated by cluster analysis. The genes regulated by c-Myc were then screened by transcriptome sequencing and miRNA sequencing. The negative binomial distribution of the DESeq software package was used to test for and determine the differential expression of genes. <b>Results:</b> In the c-Myc deletion group, 276 differently expressed mRNAs were screened out by transcriptome sequencing, of which 152 mRNAs were considerably upregulated and 124 were significantly downregulated in comparison to the control group. One-hundred-seventeen (117) differentially expressed miRNAs were found using miRNA sequencing, of which 47 showed a substantial upregulation and 70 a significant downregulation. According to the Miranda algorithm, 1803 mRNAs could be targeted by 117 differently expressed miRNAs. Comparing the two sets of data, a total of 5 miRNAs were differentially expressed after targeted binding with 21 mRNAs, which were subjected to GO and KEGG enrichment analysis. The genes regulated by c-Myc were mainly enriched in signaling pathways such as extracellular matrix receptors and Hippo. <b>Conclusion:</b> Twenty-one target genes and five differential miRNAs in the mRNA-c-Myc-miRNA regulatory network are potential therapeutic targets for triple-negative breast cancer.