miR-124 participates in the proliferation and differentiation of brain glioma stem cells through regulating Nogo/NgR expression

miR-124-3p regulates the proliferation and differentiation of retinal progenitor cells through SEPT10

Retinal degenerative diseases such as glaucoma, retinitis pigmentosa, and age-related macular degeneration pose serious threats to human visual health due to lack of effective therapeutic approaches. In recent years, the transplantation of retinal progenitor cells (RPCs) has shown increasing promise in the treatment of these diseases; however, the application of RPC transplantation is limited by both their poor proliferation and their differentiation capabilities. Previous studies have shown that microRNAs (miRNA) act as essential mediators in the fate determination of stem/progenitor cells. In this study, we hypothesized that miR-124-3p plays a regulatory role in the fate of RPC determination by targeting Septin10 (SEPT10) in vitro. We observed that the overexpression of miR124-3p downregulates SEPT10 expression in RPCs, leading to reduced RPC proliferation and increased differentiation, specifically towards both neurons and ganglion cells. Conversely, antisense knockdown of miR-124-3p was shown to boost SEPT10 expression, enhance RPC proliferation, and attenuate differentiation. Moreover, overexpression of SEPT10 rescued miR-124-3p-caused proliferation deficiency while weakening the enhancement of miR-124-3p-induced-RPC differentiation. Results from this study show that miR-124-3p regulates RPC proliferation and differentiation by targeting SEPT10. Furthermore, our findings enable a more comprehensive understanding into the mechanisms of proliferation and differentiation of RPC fate determination. Ultimately, this study may be useful for helping researchers and clinicians to develop more promising and effective approaches to optimize the use of RPCs in treating retinal degeneration diseases.

Prognostic role of METTL1 in glioma

Background

Current treatment options for glioma are limited, and the prognosis of patients with glioma is poor as the available drugs show low therapeutic efficacy. Furthermore, the molecular mechanisms associated with glioma remain poorly understood. METTL1 mainly catalyzes the formation of N(7)-methylguanine at position 46 of the transfer RNA sequence, thereby regulating the translation process. However, the role of METTL1 in glioma has not been studied to date. The purpose of this study was to analyze the expression and prognosis of METTL1 in glioma, and to explore the potential analysis mechanism.

Methods

Data from five publicly available databases were used to analyze METTL1 expression across different tumor types and its differential expression between carcinoma and adjacent normal tissues. The expression of METTL1 in glioma was further validated using real-time polymerase chain reaction and immunohistochemistry. Meanwhile, siRNA was used to knockdown METTL1 in U87 glioma cells, and the resultant effect on glioma proliferation was verified using the Cell Counting Kit 8 (CCK8) assay. Furthermore, a nomogram was constructed to predict the association between METTL1 expression and the survival rate of patients with glioma.

Results

METTL1 expression increased with increasing glioma grades and was significantly higher in glioma than in adjacent noncancerous tissues. In addition, high expression of METTL1 promoted cell proliferation. Moreover, METTL1 expression was associated with common clinical risk factors and was significantly associated with the prognosis and survival of patients with glioma. Univariate and multivariate Cox regression analyses revealed that METTL1 expression may be used as an independent prognostic risk factor for glioma. Furthermore, results of functional enrichment and pathway analyses indicate that the mechanism of METTL1 in glioma is potentially related to the MAPK signaling pathway.

Conclusions

High METTL1 expression is significantly associated with poor prognosis of patients with glioma and may represent a valuable independent risk factor. In addition, high expression of METTL1 promotes glioma proliferation and may regulate mitogen-activated protein kinase (MAPK) signaling pathway. Thus, METTL1 may be a potential biomarker for glioma. Further investigations are warranted to explore its clinical use.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-021-02346-4.

AKT2 drives cancer progression and is negatively modulated by miR-124 in human lung adenocarcinoma

BACKGROUND

AKT2 is highly expressed in many human cancers, including non-small cell lung cancer (NSCLC). Accumulating evidence has also revealed that AKT2 can promote NSCLC cell proliferation and metastasis. However, the involved mechanism remains unclear. Herein, our study mainly explored the function of AKT2 during cancer progression and uncovered a new post-transcriptional mechanism of AKT2 expression in lung adenocarcinoma (LUAD).

METHODS

Quantitative real-time (qRT-PCR), western blot and immunohistochemistry (IHC) assays were performed to detect the expression of AKT2 and other proteins. Cell counting kit-8 (CCK-8), colony formation and EdU assays were performed to assess cell proliferation. Flow cytometry analysis was used to detect changes in the cell cycle and apoptosis. Transwell assays were used to evaluate cell migration and invasion. Additionally, a luciferase reporter assay and western blotting were employed to assess miR-124 targeting of AKT2. Xenograft mouse model was used to observe the role of miR-124/AKT2 axis on the occurrence and development of LUAD.

RESULTS

We showed that AKT2 was highly expressed in NSCLC tissues and closely related to the poor prognosis of LUAD patients. Moreover, AKT2 affected LUAD cell proliferation, migration and invasion by regulating the cell cycle and promoting the occurrence of epithelial-mesenchymal transition (EMT) and the expression of matrix metalloproteinases (MMPs). In addition, we demonstrated that miR-124 overexpression downregulated AKT2 expression by binding to the 3'-untranslated region (3'- UTR) of AKT2 and thus inhibited the occurrence and development of LUAD in vivo and in vitro.

CONCLUSIONS

Our results suggest that miR-124 overexpression can negatively regulate AKT2 and thus inhibit the progression of LUAD. Therefore, the miR-124/AKT2 axis may serve as a potential target for novel therapies for LUAD.

MicroRNA-448 modulates the progression of neuropathic pain by targeting sirtuin 1

MicroRNAs (miRNAs) play crucial roles in the pathogenesis of neuropathic pain. The present study investigated the effects of miR-448 on the progression of neuropathic pain in a rat model of chronic constriction injury (CCI) of the sciatic nerve. Reverse-transcription quantitative polymerase chain reaction was conducted to detect the gene expression. The paw withdrawal threshold (PWT) and paw withdrawal latency (PWL) were used to assess the pain threshold. The protein expression levels of interleukin (IL)-6, IL-1β and tumor necrosis factor-α (TNF-α) were detected by ELISA. The target of miR-448 was predicted by TargetScan software. The Student's t-test or one-way ANOVA were used to identify statistical differences among groups. miR-448 was persistently upregulated in CCI rats, and both mechanical allodynia and thermal hyperalgesia in CCI rats were decreased following miR-448 downregulation. The expression levels of IL-1β, IL-6 and TNF-α were significantly increased in CCI rats compared with controls, and these effects were reversed following treatment with a miR-448 inhibitor. A luciferase reporter assay revealed that sirtuin 1 (SIRT1) was a target gene of miR-448. SIRT1 was found to abrogate the effect of miR-448 on neuropathic pain development. Collectively, the results of the present study revealed that miR-448 promoted neuropathic pain in CCI rats by regulating neuroinflammation via SIRT1. Therefore, SIRT1 may be considered as a novel biomarker for neuropathic pain.