Correlation between microRNA-421 expression level and prognosis of gastric cancer

The expression of microRNA-421 (miR-421) is significantly elevated in gastric carcinoma cells, thus may play an important role in tumor occurrence. This study thus aimed to further illustrate the correlation between miR-421 expression level and the progression and prognosis of gastric carcinoma. A total of 96 gastric carcinoma tissue samples were quantified for miR-421 expression level using quantitative PCR (qPCR) method. Kaplan-Meier survival curve was further deployed to analyze the postoperative survival of all patients. No significant correlation existed between miR-421 level and general information of patients such as age, sex, tumor size, location, invasion depth, TNM stage, differentiation stage and metastasis. However, miR-421 was significantly up-regulated in those tumors with lymph node metastasis (P<0.05), while those tumors with no lymph node metastasis had normal miR-421 level as those in control group (P>0.05). These results suggested the correlation between miR-421 up-regulation and lymph node metastasis. Those patients with high miR-421 expression had significantly shorter survival time compared to normal miR-421 patients (median: 37.34 months vs. 54.23 months, P<0.01), suggesting the correlation between miR-421 expression and prognosis of gastric cancer. MiR-421 level is correlated with lymph node metastasis and prognosis of gastric carcinoma, and is worth for further investigations.