Evaluation of the Expression of Circulating miR-16 and miR-26a in the plasma of Gastric Cancer Patients in Guilan province, North of Iran

Gastric cancer (GC) is a global health problem and the second deadly type of cancer worldwide with 1000 deaths per year. Poor prognosis in the early stages is one of the burdens in the treatment of GC. MicroRNAs are 18-22 nucleotide non-coding RNAs which play critical roles in the regulation of gene expression. Nowadays, miRNAs are widely known as non-invasive biomarkers for various kinds of cancers. This study aimed to evaluate the expression level of circulating miR-16 and miR-26a in GC patients and investigate the potential prognostic role of these miRNAs.

Initially, 20 plasma samples were obtained from pre-and post-operative GC patients, and the expression of miR-16 and -26a were compared with that of 20 healthy controls. The miRNAs expression was investigated using Real-Time quantitative PCR. The association between the expression levels of these miRNAs and clinicopathological features was also investigated in this study.

MiR-16 was down-regulated in GC patients; however, miR-26a expression revealed no significant difference between patients and controls in this regard. Furthermore, the expression of two miRNAs showed no association with the grade, TNM stage, and smoking status of the patients. Eventually, decreased expression of miR-16 was not correlated with the expression level of miR-26a.

The downregulation of circulating miR-16 introduces this microRNA as a candidate biomarker for the non-invasive early prognosis of GC.