OBJECTIVES: To investigate the mechanism by which circ_EPHB4 regulates temozolomide (TMZ) sensitivity of glioma cells through the miR-424-5p/Wnt3 signal axis. METHODS: We detected the expression levels of circ_EPHB4, miR-424-5p and Wnt3 mRNA in glioma specimens from 25 patients with primary glioma and 25 patients experiencing relapse following temozolomide-based chemotherapy and in TMZ-sensitive and -resistant glioma A172 and SHG44 cells with circ_EPHB4 knockdown using qRT-PCR, and Wnt3 protein expression level was detected with Western blotting. Cell viability, colony-forming ability, and apoptosis of the cells with circ_EPHB4 knockdown were assessed, and the targeted regulation relationship between circ_EPHB4, miR-424-5p, and Wnt3 was verified by dual luciferase reporter assay and RNA immunoprecipitation (RIP) experiments. The effect of circ_EPHB4 knockdown on tumorigenesis of glioma cells was evaluated in subcutaneous tumor-bearing nude mouse models. RESULTS: The expression of circ_EPHB4 was significantly increased in glioma tissues and cells as compared with normal neural tissues and astrocytes (P=0.014). In TMZ-resistant glioma cells, circ_EPHB4 knockdown resulted in an obvious reduction of IC50 value of TMZ, inhibited cell colony formation, and promoted cell apoptosis, and these effects were reversed by miR-424-5p knockdown. The expressions of miR-424-5p and circ_EPHB4 were negatively correlated in glioma tissues (P=0.011). MiR-424-5p knockdown also attenuated the effect of circ_EPHB4 knockdown on expressions of PCNA, P-gp, MRP1 and bax. CONCLUSIONS Circ_EPHB4 regulates Wnt3 expression through "sponge adsorption" of miR-424-5p, thereby modulating TMZ-resistant glioblastoma cell clonogenesis, apoptosis, and TMZ sensitivity, suggesting the potential of circ_EPHB4 as a therapeutic target for reversing drug resistance of gliomas.
MicroRNAs/genetics* ; Humans ; Temozolomide ; Glioma/genetics* ; Animals ; Mice, Nude ; Cell Line, Tumor ; Wnt3 Protein/metabolism* ; Mice ; Apoptosis ; RNA, Circular ; Drug Resistance, Neoplasm ; Brain Neoplasms/pathology* ; Signal Transduction

OBJECTIVES: To investigate the oncogenic role of circular RNA circ_EPHB4 in glioma and its molecular mechanism. METHODS: Microarray analysis was performed to identify the differentially expressed circRNAs in glioma tissues. The effects of circ_EPHB4 on glioma cell migration, invasion and epithelial-mesenchymal transition (EMT) in vitro and tumorigenicity in vivo were assessed using scratch wound healing assay, Transwell invasion assay and nude mouse models bearing subcutaneous tumors. RNA immunoprecipitation (RIP), RNA stability assays, and gene overexpression and silencing techniques were employed to validate the synergistic regulatory effect of circ_EPHB4 and the N6-methyladenosine (m⁶A) reader protein YTHDF3 on Wnt3 expression. RESULTS: Circ_EPHB4 was significantly overexpressed by 2.3 folds (|log2FC|=1.2, P<0.01) in glioma tissues compared to the adjacent tissues, and by 2.5 folds in glioma cell line U373 compared to normal cells (P<0.001). Overexpression of circ_EPHB4 significantly enhanced migration and invasion of glioma cells, and promoted the expressions of EMT markers N-cadherin and vimentin. In the tumor-bearing mouse models, the tumor volume in circ_EPHB4 overexpression group was significantly greater than that in the control group, and the lung metastatic foci increased by 4.2 folds. Overexpression of circ_EPHB4 promoted oncogenesis by upregulating Wnt3 expression, while YTHDF3 extended the half-life of Wnt3 mRNA in an m⁶A-dependent manner. Simultaneous knockdown of circ_EPHB4 and YTHDF3 resulted in an obvious reduction of Wnt3 mRNA expression by up to 47% compared to its level following knocking down either circ_EPHB4 or YTHDF3 alone. CONCLUSIONS Circ_EPHB4 and YTHDF3 promote glioma progression by jointly targeting the Wnt3 signaling pathway, which may provide a new therapeutic strategy for gliomas.
Glioma/genetics* ; Humans ; Animals ; Cell Line, Tumor ; RNA-Binding Proteins/genetics* ; RNA, Circular ; Epithelial-Mesenchymal Transition ; Mice, Nude ; Cell Movement ; Wnt3 Protein/genetics* ; Mice ; Disease Progression ; Adenosine/metabolism* ; Brain Neoplasms/metabolism* ; Gene Expression Regulation, Neoplastic

Objective:To explore the application value of microsurgical tethered cord release in children with tethered cord syndrome under perioperative electro-neurophysiology monitoring.Methods:Ninety-six patients with tethered cord syndrome accepted tethered cord release in our hospital from January 2015 to December 2019 were chosen in our study; perioperative electro-neurophysiology monitoring was performed to evaluate whether there was neurological impairment. The surgical results, neuroelectrophysiological monitoring results, and follow-up results were retrospectively analyzed.Results:In these 96 patients, symptoms disappeared in 45 patients, improved in 34, not improved in 10, worsened in 3, and tethered again in 4 patients, with a total effective rate of 82.6%. No death was noted. Preoperative neuroelectrophysiological monitoring showed abnormal sensory and motor functions of lower limbs in 40 patients, and postoperative monitoring showed abnormal sensory and motor functions of lower limbs in 6 patients. Follow up was performed for an average of 13 months; symptoms improved in 79 patients, stabilized in 10 patients, and aggravated in 7 patients.Conclusion:In children with tethered cord syndrome, tethered cord release should be performed as soon as possible regardless of early neurological injury; perioperative electro-neurophysiology monitoring can protect spinal cord function, prevent nerve function injury, improve the surgical safety and improve the prognosis of these children.

CD146 Antigen ; immunology ; Fibroblasts ; immunology ; pathology ; Humans ; Scleroderma, Systemic ; drug therapy ; immunology ; pathology