No abstract

It is well known that activating transcription factor 4 (ATF4) expression is closely associated with progression of many cancers. And we found that miR-1283 could directly target the ATF4. However, the precise mechanisms of miR-1283 in glioma have not been well clarified. Our study aimed to explore the interaction between ATF4 and miR-1283 in glioma. In this study, we found that the level of miR-1283 was dramatically decreased in glioma tissues and cell lines, and the expression of ATF4 was significantly increased. And the low level of miR-1283 was closely associated with high expression of ATF4 in glioma tissues. Moreover, introduction of miR-1283 significantly inhibited proliferation and invasion of glioma cells. However, knockdown of miR-1283 promoted the proliferation and invasion in glioma cells. Bioinformatics analysis predicted that the ATF4 was a potential target gene of miR-1283. Luciferase reporter assay demonstrated that miR-1283 could directly target ATF4. In addition, knockdown of ATF4 had the similar effects with miR-1283 overexpression on glioma cells. Up-regulation of ATF4 in glioma cells partially reversed the inhibitory effects of miR-1283 mimic. Overexpression of miR1283 inhibited cell proliferation and invasion of glioma cells by directly down-regulating ATF4 expression.

Background: Ubiquitination-mediated M1/M2 macrophage polarization plays important roles in the pathogenesis of immune disease. However, the regulatory mechanism of ubiquitination during M1/M2 macrophage polarization following intracerebral hemorrhage (ICH) has not been well studied. Methods: In the experiment, macrophages were administered with erythrocyte lysates, and then miR-494-, Nrdp1-, and M1/M2-related markers were analyzed. Brain inflammatory response, brain edema, and neurological functions of ICH mice were also assessed. Results: We found that miR-494 levels increased while Nrdp1 levels decreased in macrophages after ICH. We also demonstrated that miR-494 inhibited Nrdp1 expression by directly binding its 3′-untranslated region. MiR-494 attenuated C/EBP-β activation and downstream proinflammatory factor production. Upregulation of Nrdp1 in macrophages significantly promoted M2 macrophage polarization via ubiquitinating and activating C/EBP-β. Moreover, the results indicated that miR-494 could enhance M1 macrophage polarization, promote brain edema, and impair neurological functions in ICH mice. Conclusions: Taken together, our results demonstrated that Nrdp1 contributed to M1/M2 macrophage polarization and neuroinflammation via ubiquitination and activation of C/EBP-β in ICH. miR-494 may provide a promising therapeutic clue for ICH.

No abstract

Glioma is a malignant brain tumor exhibiting high levels of proliferation and metastasis, and these have been related to its poor prognosis and high mortality rate. MicroRNA (miRNA)-325-3p exhibits tissue-specific expression profiles and is aberrantly expressed in multiple types of malignant tumors. Our research focuses on determining the function and mechanism of action of miR-325-3p in glioma. The relative expression levels of miR-325-3p in glioma tumor tissues and cell lines were verified by qRT-PCR. The effect of 325-3p on glioma tumor cell behavior was assessed using CCK-8 assays, EDU staining, colony formation assays, flow cytometry, transwell invasion assays, and a xenograft model. In addition, we searched for miR-325-3p targets, and their potential mechanism of action was demonstrated using a reporter assay and rescue experiments. Results showed that the expression levels of miR-325-3p in glioma cancer tissues and tumor cell lines were significantly lower than that of normal paired adjacent tissue or normal cell lines. Functional experiments illustrated that tumor proliferation, migration and invasion were suppressed via upregulation of miR-325-3p. To assess whether FOXM1 is a target of miR-325-3p, we examined this hypothesis using a luciferase report assay and then found that miR-325-3p could modulate the expression of FOXM1. Furthermore, the functional role of miR-325-3p was also confirmed in a xenograft model using nude mice. Together, our data demonstrated that in glioma, miR-325-3p may inhibit cancer cell growth through the suppression of FOXM1 and could be a promising new target for treating this type of brain cancer.