关键词: 脑胶质瘤, CYB561D2, miR-216b, 靶向调控

Abstract: Objective To investigate the regulatory relationship and mechanism between microRNA-216b (miR-216b) and its potential target gene Cytochrome b561 domain-containing protein 2 (CYB561D2) in gliomas.Methods Fifty-six pairs of glioma tissues and adjacent normal tissues were collected from Anqing Municipal Hospital.qRT-PCR and immunohistochemistry were used to detect the protein and mRNA expression of CYB561D2,and its correlation with miR-216b was analyzed.Bioinformatics databases were employed to predict miR-216b target genes,and dual-luciferase reporter assays were performed to validate the targeting relationship.Cell transfection,Western blotting,and qRT-PCR were used to investigate the regulatory effect of miR-216b on CYB561D2 expression in U251 and U87 glioma cells.Results Bioinformatics analysis showed that the 3'-UTR region of CYB561D2 contained conserved binding sites for miR-216b.Clinical tissue detection revealed that CYB561D2 mRNA (2.38±0.65 vs.1.00±0.21,P＜0.01) and protein (high expression rate:67.9% vs.14.3%,P＜0.01) levels in glioma tissues were significantly higher than those in adjacent normal tissues,and negatively correlated with miR-216b expression (r=-0.684,P＜0.01).Cell experiments confirmed that CYB561D2 protein was significantly upregulated in U251 and U87 cells compared with normal astrocytes.Transfection with miR-216b mimics significantly reduced CYB561D2 mRNA and protein expression in U251 and U87 cells (P＜0.01).Dual-luciferase reporter assays showed that miR-216b directly bound to the 3'-UTR region of CYB561D2 to inhibit its expression.Conclusion miR-216b directly targets CYB561D2 and inhibits its expression in gliomas,with a negative correlation between the two.The miR-216b/CYB561D2 axis may serve as a new direction for molecular diagnosis and targeted therapy of gliomas,although the in vivo functions and downstream mechanisms of this axis require further investigation.

Key words: Glioma, miR-216b, CYB561D2, Targeted regulation