[MiR-26b inhibits proliferation, invasion, and migration of glioma by targeting cyclooxygenase-2].

ABSTRACT

OBJECTIVE: To explore the expressions of miR-26b and cyclooxygenase (COX)-2 in different grades of gliomas and the effect of miR-26b on glioma cell proliferation, invasion and migration.
 Methods: Western blot and Real-time quantitative PCR (qRT-PCR) were used to detect the expression levels of miR-26b and COX-2 in different grades of gliomas. Human glioma cells were transfected with miR-26b mimics. qRT-PCR was employed to detect the mRNA expressions of miR-26b and COX-2 after miR-26b mimics transfection, while dual-luciferase reporter assay was used to investigate the regulatory effect of miR-26b on COX-2. Cell counting kit-8 (CCK8), trans-well invasion assay and scratch assay were used to detect the proliferation, invasion and migration of human U87 glioma cells after miR-26b mimic transfection, respectively. The antitumor effect of miR-26b was verified by evaluating the volume and weight of tumor in nude mice.
 Results: With the increase in tumor grades, the expression of miR-26b was significantly decreased (P<0.05), while COX-2 expression was increased (P<0.001). Dual luciferase assay confirmed that miR-26b could directly regulate the protein expression of COX-2. MiR-26b mimics could significantly reduce the expression of COX-2 (P<0.05) and suppress the proliferation, invasion and migration of glioma cell (P<0.05). The volume and weight of tumor in MiR-26b mimics transfection group were smaller than those in the control group.
 Conclusion: Overexpression of miR-26b may inhibit proliferation, invasion, and migration of glioma by suppressing the expression of COX-2. Therefore, the miR-26b/COX-2 pathway might be a therapeutic target in glioma.