The Expression And Clinical Significance Of MicroRNA-106b～25in Tissue And Plasma Of Gastric Cancer

Objective:To explore the variation of the expression level of microRNA-106b-25(miRNA-106b-25) cluster between gastric cancer tissue and surgical margin tissue, to investigate the correlation of their expressions and to evaluate the relations of these microRNAs with clinicopathological features. To establish a method to extract microRNAs from plasma, and analysize the expression level of miRNA-106b-25cluster in plasma of gastric cancer patients and healthy controls. Detect miRNA-106b-25cluster in plasma as an indicator of gastric cancer.Methods:Taqman stem-loop real-time qRT-PCR method was used to assess the expression of miRNA-106b-25cluster in the gastric cancer (40resectable cases of gastric cancer tissues and normal adjacent tumor tissues) and that in plasma (including20gastric cancer patients and20healthy controls). The pathologic and clinical data of the patients with gastric cancer were collected from Tianjin cancer hospital. The correlation of miRNA-106b-25expressions in gastric cancer tissues and plasma were analyzed, and the correlation of these miRNAs expressions and clinicopathological features or gastrointestinal tumor markers were also analyzed.Results:1. The expression level of miRNA-106b-25were significantly higher in gastric cancer tissues than that in normal adjacent tumor tissues (P<0.05).2. The expression level of miRNA-106b, miRNA-93and miRNA-25had correlation with tumor size, Borrmann type, depth of invation, lymph node metastasis, distant metastasis and TNM staging (P<0.05), and no correlation with sex, age, tumor location and blood type. And the expression level of miRNA-106b had correlation with pathological type of tumor in gastric cancer tissues (P<0.05).3. The expression level of miRNA-106b-25in plasma of gastric cancer patients were significantly higher than that of health control group (P<0.05).4. The expression level of miRNA-106b, miRNA-93and miRNA-25in plasma had correlation with tumor size, serosal invasion and TNM staging (PO.05), while no correlation with sex, age, tumor location, Borrmann type, blood type and pathological type of tumor (P>0.05). And the expression level of miRNA-93and miRNA-25in plasma had correlation with lymph node metastasis and distant metastasis (P<0.05).5. The expression level of miRNA-106b, miRNA-93and miRNA-25in tumor tissue or in plasma were significantly correlated. And the expression level of miRNA-106b had positive correlation with CA19-9(r2=0.467, P=0.002), miRNA-93and miRNA-25with CA242and CA19-9in gastric cancer tissues (r2=0.341, P=0.032,r2=0.536, P=0.000; r2=0.373, P=0.018, r2=0.565, P=0.000). The expression level of miRNA-106b had positive correlation with CA242(r2=0.490, P=0.028), miRNA-93and miRNA-25with CEA in plasma (r2=0.552, P=0.012,r2=0.504, P=0.024).Conclusion:1. The higher expression level of miRNA-106b-25cluster in gastric cancer tissues and correlation with clinicopathological features indicate that these miRNAs play important roles in the proression of gastric cancer, with some clinical value. MiRNA-106b-25cluster plays an important role in the process of tumorigenesis, and these miRNAs might act as oncogenes. Therefore, targeting these genes may be a new approach to treat gastric cancer.2. The higher expression level of miRNA-106b-25cluster in plasma of gastric cancer patients and the positive correlation with some gastrointestinal tumor markers demonstrate that it can serve as a potential tumor marker. The significant correlation among the expression level of miRNA-106b, miRNA-93and miRNA-25suggest that they may be transcribed synergistically.