Abstract. MicroRNAs (miRs) serve a regulatory function in oxidative radical-mediated inflammation and apoptosis during ischemia/reperfusion (IR) injury. Lipocalin 2 (Lcn-2), a target protein of miR-138, is widely involved in the systemic response to IR injury. The aim of the present study was to investigate the association between miR-138 and Lcn-2 in a rat model of cerebral ischemia/reperfusion (CIR) injury and to verify the interaction between miR-138 and Lcn-2 in a PC12 cell model of hypoxia/reoxygenation injury. Reverse transcription-quantitative polymerase chain reaction and western blot analysis were used to detect the mRNA and protein expression levels of miR-138 and Lcn-2. Cell proliferation was determined by MTT assay. The results suggested that the expression of miR-138 was inversely correlated with the expression of Lcn-2 in the CIR rat model and the PC12 cells subjected to hypoxia and reoxygenation. The expression of Lcn-2 was inhibited by miR-138 mimics and enhanced by miR-138 inhibitors, thereby indicating that miR-138 functions as a negative regulator for Lcn-2 expression. This study provides an experimental basis for the further study of miR-138-based therapy for CIR injury.

Introduction: Glioblastoma (GBM) is the most common and malignant variant of intrinsic glial brain tumors. The poor prognosis of GBM has not significantly improved despite the development of innovative diagnostic methods and new therapies. Therefore, further understanding the molecular mechanism that underlies the aggressive behavior of GBM and the identification of appropriate prognostic markers and therapeutic targets is necessary to allow early diagnosis, to develop appropriate therapies and to improve prognoses. Methods: We used a weighted gene co-expression network analysis (WGCNA) to construct a gene co-expression network with 524 glioblastoma samples from The Cancer Genome Atlas (TCGA). A risk score was then constructed based on four module genes and the patients' overall survival (OS) rate. The prognostic and predictive accuracy of the risk score were verified in the GSE16011 cohort and the REMBRANDT cohort. Results: We identified a gene module (the green module) related to prognosis. Then, multivariate Cox analysis was performed on 4 hub genes to construct a Cox proportional hazards regression model from 524 glioblastoma patients. A risk score for predicting survival time was calculated with the following formula based on the top four genes in the green module: risk score = (0.00889 × EXP CLEC5A ) + (0.0681 × EXP FMOD ) + (0.1724 × EXP FKBP9 ) + (0.1557 × EXP LGALS8 ). The 5-year survival rate of the high-risk group (survival rate: 2.7%, 95% CI: 1.2–6.3%) was significantly lower than that of the low-risk group (survival rate: 8.8%, 95% CI: 5.5–14.1%). Conclusions: This study demonstrated the potential application of a WGCNA-based gene prognostic model for predicting the survival outcome of glioblastoma patients.

As one of the natural herbal flavonoids, myricetin has attracted much research interest, mainly owing to its remarkable anticancer properties and negligible side effects. It holds great potential to be developed as an ideal anticancer drug through improving its bioavailability. This study was performed to investigate the effects of Pluronic-based micelle encapsulation on myricetin-induced cytotoxicity and the mechanisms underlying its anticancer properties in human glioblastoma cells. Cell viability was assessed using a methylthiazol tetrazolium assay and a real-time cell analyzer. Immunoblotting and quantitative reverse transcriptase polymerase chain reaction techniques were used for determining the expression levels of related molecules in protein and mRNA. The results indicated that myricetin-induced cytotoxicity was highly potentiated by the encapsulation of myricetin. Mitochondrial apoptotic pathway was demonstrated to be involved in myricetin-induced glioblastoma cell death. The epidermal growth factor receptor (EGFR)/PI3K/Akt pathway located in the plasma membrane and cytosol and the RAS-ERK pathway located in mitochondria served as upstream and downstream targets, respectively, in myricetin-induced apoptosis. MiR-21 inhibitors interrupted the expression of EGFR, p-Akt, and K-Ras in the same fashion as myricetin-loaded mixed micelles (MYR-MCs) and miR-21 expression were dose-dependently inhibited by MYR-MCs, indicating the interaction of miR-21 with MYR-MCs. This study provided evidence supportive of further development of MYR-MC formulation for preferentially targeting mitochondria of glioblastoma cells.