RESUMO
Objective:To detect the expression of miR-106b~25 cluster in glioma cell line and tissues. Methods:Real-time PCR was performed to determine the expression of miR-106b~25 cluster members (miR-106b, miR-93, and miR-25) in different human glio-blastoma cell lines. Different pathological grade glioma specimens were surgically removed. In-situ hybridization was performed to de-tect the expression of miR-106b~25 cluster members in different pathological levels of glioma tissues. Results:In the expression of the benchmark on normal brain tissues, three kinds of miRNAs in all test cell lines have a tendency to increase. Based on the expression of the pathological level I average rate in 43 cases of glioma specimens collected after neurosurgical operations, the real-time PCR results showed that the average expression quantity of the three kinds of miRNAs in each group gradually increase. The increase in tumor path-ological levels results in statistically significant expression differences of miR-106b and miR-93 between the groups (F=4.479, P=0.018 and F=3.493, P=0.040, respectively). However, miR-25 expression differences between the groups have no statistically signifi-cant differences (F=2.766, P=0.075). In situ hybridization results show that the expressions of three miRNAs in high grade gliomas are significantly higher than that in the low-level tumor. Spearman rank correlation analysis results indicate that the expression of these miRNAs signal-intensity distribution is positively correlated with glioma, in accordance with WHO pathology classification. The corre-lation coefficient for miR-106b, miR-93, and miR-25 are 0.617, 0.438, and 0.463, respectively (P<0.001). Conclusion:The expression of miR-106b~25 cluster members is up-regulated in the glioma and is positively correlated with tumor grade.
RESUMO
miR-106b-25 cluster is composed of miR-106b,miR-93 and miR-25,and is a paralogue of miR-17-92 cluster.Some studies have shown that the members in miR-106b-25 cluster abundantly expressed in many cancers.Over-expressions of these miRNAs promote the growth of tumor cells by negatively regulating p21 and p57,and suppress the apoptosis of tumor cells through inhibition of Bim.Moreover,high expression of miR-106b-25 cluster might endue tumor cells with resistance to inhibitory effect of cell growth induced by TGF-β signaling.