Changes in Expression of miRNA-320a and miRNA-497-5p in Early Stage of Breast Cancer

 Micro-ribonucleic acids (miRNAs) are noncoding small RNA species considered a varying class with a single-stranded structure whose expression is often dysregulated in cancer. The expression of miRNAs has been used as a promising new biomarker for the detection of breast cancer (BC).  

 The purpose of the present case-control study was to investigate the expression levels of miRNA-320a and miRNA-497-5p and their potential role in BC patients in comparison to those of the healthy controls in the Cellular and Molecular Biology Research Center, Health Research Institute, Babol University of Medical Sciences, Babol, Iran, in 2019. 

 The concentrations of miR-320a and miR-497-5p were analyzed in 80 serum samples of 40 patients with a confirmed diagnosis of early-stage BC in comparison to those of 40 age-matched healthy volunteers. Real-time quantitative polymerase chain reaction was carried out for the detection of the expression level of these miRNAs.

 The results of the current study showed that the serum levels of miR-320a and miR-497-5p were down-regulated in the BC patients, compared to those reported for the healthy controls  (P=0.651 and P=0.044, respectively). However, the levels of miR-320a in the early-stage BC samples were not statistically different from those of the healthy volunteers. There was a reduction in the serum miRNA-320a of the premenopausal subjects under 48 years of age. Serum miRNA-497-5p also decreased among the cases under 48 years of age.

 The identification and effectiveness of these miRNAs were demonstrated in the early-stage BC screening. It seems that miRNAs have the potential to be used as biomarkers for the screening and diagnosis of BC.