The role of miR-223 in breast cancer; an integrated analysis

Breast cancer (BRCA) is the most common and leading cause of cancer-related death in women. MicroRNAs (miRNAs) are short non-coding RNA fragments that play a role in regulating gene expression including the cancer-related pathways. Although dysregulation of miR-223 has been demonstrated in recent studies to have prognostic value in various cancers, its diagnostic and prognostic role in BRCA remains unknown.

The expression and the prognostic value of miR-223 were evaluated using the TCGA data and verified by qRT-PCR. Subsequently, potential oncogenic targets of miR-223 were identified by using three different miRNA target prediction tools and the GEPIA database. In addition to these databases, protein-protein interaction network, molecular functions, prognostic value, and the expression level of miR-223 targets were included by using several other bioinformatics tools and databases; such as, UALCAN, GeneMANIA and Metascape.

The bioinformatic results demonstrated that miR-223 downregulated in BRCA and associated with poor prognosis of patients. In vitro experiments validated that miR-223 significantly downregulated in BRCA cells, MCF-7, SK-BR3, MDA-MB-231 and HCC1500, compared to normal breast cell line hTERT-HME1. Furthermore, ANLN, DYNLT1, LRRC59, SLC12A8 and TPM3 genes were identified as the potential oncogenic target genes of miR-223 based on their expression and prognosis in BRCA. Additionally, protein-protein interaction network of these target genes was mainly enriched in dynein intermediate chain binding, cell division, regulation of cell cycle process, and positive regulation of cellular component biogenesis.

The results suggests that miR-223 and its targets, ANLN, DYNLT1, LRRC59, SLC12A8 and TPM3, might be reliable potential prognostic biomarkers in BRCA patients.