Extracellular vesicles carry miR-27a-3p to promote drug resistance of glioblastoma to temozolomide by targeting BTG2.

OBJECTIVE: Glioblastoma (GBM) is the most common central nervous system tumor. Temozolomide (TMZ) is a commonly used drug for GBM management. This study explored the mechanism of extracellular vesicles (EVs) regulating TMZ-resistance in GBM. METHODS: LN229 cells were inducted into TMZ-resistant LN229r strain by stepwise induction. After the intervention of miR-27a-3p expression, cell viability of GBM cells treated with different concentrations of TMZ was detected by MTT and IC50 value was calculated. Cell proliferation and apoptosis were detected by colony formation and flow cytometry. EVs extracted from LN18 cells were identified and the internalization of EVs by LN229r cells was evaluated. The 100 µmol/L TMZ-treated LN229r cells were treated with EVs or EVs with downregulated miR-27a-3p to verify the effect of EVs-carried miR-27a-3p on TMZ resistance. The binding relation between BTG2 and miR-27a-3p was verified. miR-27a-3p and BTG2 expressions in GBM cells and EVs were detected by RT-qPCR. The BTG2 effect on TMZ-resistance in GBM was verified. The xenograft tumor nude mouse model was established by injecting LN229r cells and treated with EVs and 100 µmol/L TMZ. RESULTS: miR-27a-3p was highly expressed in LN229r cells. IC50 value and proliferation of LN229r cells with silenced miR-27a-3p were decreased and apoptosis was increased, indicating that miR-27a-3p silencing reduced the drug-resistant cell LN229r resistance to TMZ. LN18-derived EVs could be internalized by LN229r cells, and release its encapsulated miR-27a-3p into LN229r cells and increase miR-27a-3p expression. EV treatment increased LN229r cell proliferation and reduced apoptosis, while EVs with silenced miR-27a-3p showed the opposite trend. miR-27a-3p targeted BTG2. BTG2 overexpression reduced LN229r cell resistance to TMZ. In vivo, after EVs treatment, tumor volume and weight, Ki67-positive rate, and miR-27a-3p were increased, while BTG2 expression was decreased. CONCLUSION: GBM-derived EVs were internalized by GBM cells, released miR-27a-3p into GBM cells, upregulated miR-27a-3p expression, and targeted BTG2, thus promoting TMZ resistance.

Prognostic value of serum pentraxin 3 for intracerebral hemorrhage mortality.

Pentraxin 3 is considered an important inflammatory marker is known to increase in patients with ischemic stroke, but the relationship between pentraxin 3 and intracerebral hemorrhage mortality is unclear. The purpose of this study is to investigate the level of pentraxin 3 in serum and its impact on prognosis in 307 patients with intracerebral hemorrhage. During the 5-year follow-up, the mortality rate of patients with intracerebral hemorrhage was 22.5%. The serum pentraxin 3 level of the brain-dead patients was higher than that of the control group (P < 0.05). Logistic regression analysis indicated a high correlation between the pentraxin 3 level and the mortality rate 95% (hazard ratio: 3.671; confidence interval: 1.558-4.297). The receiver operating characteristic curve showed that pentraxin 3 (Area Under Curve = 0.801) had a higher diagnostic value than C-reactive protein (Area Under Curve = 0.701). The pentraxin 3 level increased significantly after intracerebral hemorrhage and has an important predictive value for a prognosis for intracerebral hemorrhage mortality.

MicroRNA­940 promotes cell proliferation and invasion of glioma by directly targeting Kruppel­like factor 9.

MicroRNA­940 (miR­940) has been extensively studied in the pathogenesis of numerous types of human cancer; however, the expression pattern, roles and molecular mechanisms underlying the regulatory actions of miR­940 in glioma remain unknown. The present study aimed to further investigate miR­940 by studying its expression, roles and mechanisms of action in glioma. Reverse transcription­quantitative polymerase chain reaction (RT­qPCR) was used to detect miR­940 expression in glioma tissues and cell lines. The regulatory effects of miR­940 in glioma cell proliferation and invasion were determined using MTT and cell invasion assays. Bioinformatics analyses was performed to identify the potential target of miR­940, which was further confirmed by luciferase reporter assay, RT­qPCR and western blot analysis. In the present study, significantly increased miR­940 expression levels were observed in glioma tissues and cell lines compared with normal brain tissues and normal human astrocytes, respectively. Decreased miR­940 expression levels attenuated glioma cell proliferation and invasion in vitro. Kruppel­like factor 9 (KLF9) was predicted as a potential target of miR­940. Further assays demonstrated that miR­940 negatively regulated KLF9 expression in glioma cells by directly targeting the 3'­untranslated regions of KLF9. Additionally, KLF9 expression was downregulated in glioma tissues and was inversely correlated with miR­940. Furthermore, KLF9 knockdown was able to rescue the effects of miR­940 on glioma cell proliferation and invasion. The results of the present study suggest that miR­940 may function as an oncogene in glioma by targeting KLF9 and may be a considered a therapeutic target for the treatment of gliomas.