Correlation between the Expression Levels of circulating miR-21 and miR-192 and Clinicopathological Features in Plasma of Patients with Gastric Cancer in Iran

Gastric cancer (GC) is the most prevalent malignancy worldwide and a common cause of death in Iran. Studies have proved that a variety of dysregulated microRNAs is involved in the development and progression of gastric cancer. The present study aimed to evaluate the expression levels of plasma circulating oncogenic miR-21 and miR-192 and their association with clinical phenotypes of patients with gastric cancer in the north of Iran.

Clinico-pathological analysis was conducted using a standard protocol and pathological tests. The expression levels of miR-21 and miR-192 were measured using quantitative reverse transcription-polymerase chain reaction in the plasma of twenty pre/post-operative gastric cancer patients and twenty healthy subjects. The receiver operating characteristic (ROC) curve of these microRNAs was analyzed to investigate their diagnosis properties.

The study results indicated that plasma miR-21 expression was significantly associated with tumor stage and helicobacter pylori infection status (P=0.024, P=0.0004, respectively). However, no association was observed between clinic-pathological characteristics and miR-192 expression. The results showed that the plasma levels of miR-21 (P=0.0001) and miR-192 (P=0.0007) were significantly higher in GC patients compared to those in healthy individuals. Furthermore, the ROC analyses yielded the mean ±SD area under the curve (AUC) values of 0.9525±0.03 (P<0.0001) and 0.5925±0.09 (P=0.316) for miR-21 and miR-192, respectively. Pearson regression analysis showed that there was no significant correlation between the expression of miR-21 and miR-192 (P=0.1507).

Based on the obtained results, the expression of the plasma level of miR-21 was significantly higher in gastric cancer patients compared to that in the healthy group. Furthermore, the higher levels of AUC in miR-21 indicated the potential role of miR-21 as a noninvasive biomarker for the prognosis of gastric cancer in the population of the north of Iran.