MiRNA-323-5p Promotes U373 Cell Apoptosis by Reducing IGF-1R

Methods of miRNA delivery and possibilities of their application in neuro-oncology

In the current phase of medical progress, practical neuro-oncology faces critical challenges. These include the quest for and development of innovative methodological approaches, as well as the enhancement of conventional therapies to boost their efficacy in treating brain tumors, especially the malignant varieties. Recent strides in molecular and cellular biology, molecular genetics, and immunology have charted the primary research pathways in the development of new anti-cancer medications, with a particular focus on microRNA (miRNA)-based therapy. MiRNAs possess the ability to function as suppressors of tumor growth while also having the potential to act as oncogenes. MiRNAs wield control over numerous processes within the human body, encompassing tumor growth, proliferation, invasion, metastasis, apoptosis, angiogenesis, and immune responses. A significant impediment to enhancing the efficacy of brain tumor treatment lies in the unresolved challenge of traversing the blood-brain barrier (BBB) and blood-tumor barrier (BTB) to deliver therapeutic agents directly to the tumor tissue. Presently, there is a worldwide effort to conduct intricate research and design endeavors aimed at creating miRNA-based dosage forms and delivery systems that can effectively target various structures within the central nervous system (CNS). MiRNA-based therapy stands out as one of the most promising domains in neuro-oncology. Hence, the development of efficient and safe methods for delivering miRNA agents to the specific target cells within brain tumors is of paramount importance. In this study, we will delve into recent findings regarding various methods for delivering miRNA agents to brain tumor cells. We will explore the advantages and disadvantages of different delivery systems and consider some clinical aspects of miRNA-based therapy for brain tumors.

MicroRNAs, Key Regulators in Glioma Progression as Potential Therapeutic Targets for Chinese Medicine

Gliomas are tumors of the primary central nervous system associated with poor prognosis and high mortality. The 5-year survival rate of patients with gliomas received surgery combined with chemotherapy or radiotherapy does not exceed 5%. Although temozolomide is commonly used in the treatment of gliomas, the development of resistance limits its use. MicroRNAs are non-coding RNAs involved in numerous processes of glioma cells, such as proliferation, migration and apoptosis. MicroRNAs regulate cell cycle, PI3K/AKT signal pathway, and target apoptosis-related genes (e.g., BCL6), angiogenesis-related genes (e.g., VEGF) and other related genes to suppress gliomas. Evidence illustrates that microRNAs can regulate the sensitivity of gliomas to temozolomide, cisplatin, and carmustine, thereby enhancing the efficacy of these agents. Moreover, traditional Chinese medicine (e.g., tanshinone IIA, xanthohumol, and curcumin) exert antiglioma effects by regulating the expression of microRNAs, and then microRNAs inhibit gliomas through influencing the process of tumors by targeting certain genes. In this paper, the mechanisms through which microRNAs regulate the sensitivity of gliomas to therapeutic drugs are described, and traditional Chinese medicine that can suppress gliomas through microRNAs are discussed. This review aims to provide new insights into the traditional Chinese medicine treatment of gliomas.

MicroRNA-3200-3p targeting CAMK2A modulates the proliferation and metastasis of glioma in vitro

MicroRNA (miRNA) is strongly interrelated with the pathogenesis of glioma. However, its potential biological effect and underlying mechanism of miR-3200-3p in human glioma remain elusive. In the current study, we checked the level of miR-3200-3p in different glioma cells. Then, its biological functions on glioma cell proliferation metastasis was investigated using the miR-3200-3p mimic and inhibitor. The direct target of miR-3200-3p was tested in these cells. Results demonstrated that miR-3200-3p is remarkably downregulated in human glioma cells. The relative level of miR-3200-3p is strongly associated with biological features, including proliferation, colony formation, and metastasis. Additionally, Ca²⁺/calmodulin dependent kinase 2a (CAMK2A) might be the direct target gene of miR-3200-3p, and CAMK2A overexpression reversed the anticancer roles of miR-3200-3p on glioma cellular function. Importantly, these results further showed that miR-3200-3p downregulated the proliferation and metastasis by suppressing the expression of CAMK2A, thus regulating the Ras/Raf/MEK/ERK pathway. This study provided provided insights into the biological role of miR-3200-3p, which might function as a potential biomarker in glioma therapy.

Spectrum of microRNAs and their target genes in cancer: intervention in diagnosis and therapy

Till date, several groups have studied the mechanism of microRNA (miRNA) biogenesis, processing, stability, silencing, and their dysregulation in cancer. The miRNA coding genes recurrently go through abnormal amplification, deletion, transcription, and epigenetic regulation in cancer. Some miRNAs function as tumor promoters while few others are tumor suppressors based on the transcriptional regulation of target genes. A review of miRNAs and their target genes in a wide range of cancers is attempted in this article, which may help in the development of new diagnostic tools and intervention therapies. The contribution of miRNAs for drug sensitivity or resistance in cancer therapy and opportunities of miRNAs in cancer prognosis or diagnosis and therapy is also presented in detail.

Pentose Phosphate Pathway Regulates Tolerogenic Apoptotic Cell Clearance and Immune Tolerance

The efficient removal of apoptotic cells (ACs), a process termed as efferocytosis, is essential for immune homeostasis. While recent work has established an important interplay between efferocytosis and cellular metabolic changing, underlying mechanisms remain poorly known. Here, we discovered that pentose phosphate pathway (PPP) regulates tolerogenic ACs clearance and immune tolerance. ACs decreased levels of PPP-related genes and metabolites in macrophages. AG1, the agonist of PPP, increased the activity of PPP but greatly reduced macrophage phagocytosis of ACs and enhanced the inflammatory response during efferocytosis. miR-323-5p regulated the expression of PPP-related genes and its levels increased during efferocytosis. miR-323-5p inhibitor greatly promoted levels of PPP-related genes, reduced the macrophage phagocytosis of ACs, and increased inflammatory response during efferocytosis, suggesting that miR-323-5p was essential in regulating PPP activity and ACs clearance in macrophages. Correspondingly, the PPP agonist AG1 exacerbated the lupus-like symptoms in the AC-induced systemic lupus erythematosus (SLE) model. Our study reveals that regulating PPP-dependent metabolic reprogramming is critical for tolerogenic ACs phagocytosis and immune tolerance.

miRNA-21 plays an important role in necrotizing enterocolitis

INTRODUCTION

To investigate the role and mechanism of miRNA-21 in necrotizing enterocolitis (NEC).

MATERIAL AND METHODS

Collecting 30 pairs of newborn and NEC children and measuring the miRNA-21 expression in the serum of 30 pairs. Thirty neonatal Wistar rats were randomized to 3 groups: NC, Model and miRNA groups. The rats of model and miRNA groups were based on NEC model groups, after the fabricated NEC model of neonatal rats. The Model group was treated with normal saline and the miRNA group was injected with miRNA-21 from the abdomen. On the 4^th day, all the rats were executed. The intestinal tissue located at the boundary of the ileum and cecum was sampled for histology and cell apoptosis. The relative protein (PTEN, PI3K, AKT and GSK-3β) expression levels of difference groups were evaluated by WB assay.

RESULTS

In the clinical data, the miRNA-21 gene expression of NEC children was significantly up-regulation compared with that of normal newborns (p < 0.05). In the rat experiments, compared with the NC group, the pathology and cell apoptosis of the Model group showed significant deterioration (p < 0.05) and relative protein (PTEN, p-PI3K, p-AKT and p-GSK-3β) expression levels were significantly different (p < 0.05, respectively). However, the pathology and cell apoptosis of colonic tissue were significantly improved (p < 0.05), the PTEN and p-GSK-3β protein expression levels were significantly suppressed (p < 0.05) and p-PI3K and p-AKT protein expression levels were significantly increased (p < 0.05, respectively) with miRNA-21 over-expression compared with the Model group.

CONCLUSIONS

miRNA might be a biological marker and therapeutic target in NEC diagnosis and treatment.

Prognostic and Therapeutic Roles of the Insulin Growth Factor System in Glioblastoma

Glioblastoma multiforme (GBM) is the most common primary brain malignancy and is often resistant to conventional treatments due to its extensive cellular heterogeneity. Thus, the overall survival of GBM patients remains extremely poor. Insulin-like growth factor (IGF) signaling entails a complex system that is a key regulator of cell transformation, growth and cell-cycle progression. Hence, its deregulation is frequently involved in the development of several cancers, including brain malignancies. In GBM, differential expression of several IGF system components and alterations of this signaling axis are linked to significantly worse prognosis and reduced responsiveness to temozolomide, the most commonly used pharmacological agent for the treatment of the disease. In the present review we summarize the biological role of the IGF system in the pathogenesis of GBM and comprehensively discuss its clinical significance and contribution to the development of resistance to standard chemotherapy and experimental treatments.

Long non-coding RNA SNHG7 promotes neuroblastoma progression through sponging miR-323a-5p and miR-342-5p

Dysregulation of long non-coding RNAs (lncRNAs) has been known to be relevant to the progression of human cancers, including neuroblastoma (NB). Small nucleolar RNA host gene 7 (SNHG7) has been identified as an oncogene in a series of human cancers. The purpose of the present study was to investigate the function and underlying mechanism of SNHG7 in NB progression. qRT-PCR was used to determine the levels of SNHG7, cyclin D1 (CCND1), miR-323a-5p and miR-342-5p. Cell migration and invasion abilities were detected by transwell assays. Glucose consumption and lactate production were assessed using the corresponding assay kits. The targeted interaction between SNHG7 and miR-323a-5p or miR-342-5p was verified by dual-luciferase reporter and RNA immunoprecipitation (RIP) assays. Xenograft tumor assays were performed to observe the effect of SNHG7 silencing on tumor growth in vivo. We found that SNHG7 was upregulated in NB tissues and cell lines, and high SNHG7 level was relevant to poor prognosis of NB patients. SNHG7 silencing resulted in the repression of NB cell migration, invasion and glycolysis. SNHG7 directly targeted miR-323a-5p and miR-342-5p and negatively modulated their expression in NB cells. The overexpression of miR-323a-5p or miR-342-5p weakened NB cell migration, invasion and glycolysis. Moreover, miR-323a-5p or miR-342-5p mediated the suppressive effect of SNHG7 silencing on NB cell progression. CCND1 was a direct target of miR-323a-5p and miR-342-5p. Additionally, SNHG7 knockdown repressed tumor growth in vivo. In conclusion, our study suggested that SNHG7 silencing hindered NB progression at least partly though sponging miR-323a-5p and miR-342-5p, illuminating its potential value as a therapeutic target.

MicroRNA-421 improves ischemia/reperfusion injury via regulation toll-like receptor 4 pathway

Objectives

The objective was to investigate the effects of microRNA-421 against myocardial ischemia/reperfusion injury in C57BL/6 mice.

Methods

Male C57BL/6 mice (n = 27) were randomly divided into three groups: normal control (NC) group (sham-treated); I/R model group, which underwent the I_30min/R_24h model (ischemia for 30 minutes followed by reperfusion for 24 hours); and the miRNA group, which were injected with miR-421. Pathology was assessed by hematoxylin and eosin staining and myocardial infarct size was measured by triphenyltetrazolium chloride staining. The apoptosis rate was measured by TUNEL assay, and relative expression of toll-like receptor-4 (TLR4), Janus kinase 2 (JAK2), and signal transducer and activator of translation 3 (STAT3) was evaluated by immunohistochemistry. Interleukin (IL)-6, tumor necrosis factor (TNF)-α, IL-10, and high mobility group protein B1 (HMGB1) serum concentrations were measured by ELISA.

Results

Compared with the NC group, in the model group, the myocardial infarction was large; inflammatory cell infiltration was severe; apoptosis was enhanced; expression of TLR4, JAK2, and STAT3 was increased; and serum concentrations of IL-6, TNF-α, IL-10, and HMGB1 were significantly increased. In the miRNA group, the ischemia/reperfusion injury was significantly improved.

Conclusions

Overexpression of miRNA-421 could reduce ischemia/reperfusion inflammatory response, perhaps via inactivation of TLR4, JAK2, and STAT3.

Functional high-throughput screening reveals miR-323a-5p and miR-342-5p as new tumor-suppressive microRNA for neuroblastoma

Current therapies for most non-infectious diseases are directed at or affect functionality of the human translated genome, barely 2% of all genetic information. By contrast, the therapeutic potential of targeting the transcriptome, ~ 70% of the genome, remains largely unexplored. RNA therapeutics is an emerging field that widens the range of druggable targets and includes elements such as microRNA. Here, we sought to screen for microRNA with tumor-suppressive functions in neuroblastoma, an aggressive pediatric tumor of the sympathetic nervous system that requires the development of new therapies. We found miR-323a-5p and miR-342-5p to be capable of reducing cell proliferation in multiple neuroblastoma cell lines in vitro and in vivo, thereby providing a proof of concept for miRNA-based therapies for neuroblastoma. Furthermore, the combined inhibition of the direct identified targets such as CCND1, CHAF1A, INCENP and BCL-XL could reveal new vulnerabilities of high-risk neuroblastoma.

Combined Blockade of T Cell Immunoglobulin and Mucin Domain 3 and Carcinoembryonic Antigen-Related Cell Adhesion Molecule 1 Results in Durable Therapeutic Efficacy in Mice with Intracranial Gliomas

Background

Glioblastoma multiforme (GBM) evades immune surveillance by inducing immunosuppression via receptor-ligand interactions between immune checkpoint molecules. T cell immunoglobulin and mucin domain 3 (Tim-3) is a key checkpoint receptor responsible for exhaustion and dysfunction of T cells and plays a critical role in immunosuppression. Carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1) has been recently identified as a heterophilic ligand for Tim-3.

Material/Methods

We established an intracranial GBM model using C57BL/6 mice and GL261 cells, and treated the mice with single or combined monoclonal antibodies (mAbs) against Tim-3/CEACAM1. The CD4⁺, CD8⁺, and regulatory T cells in brain-infiltrating lymphocytes were analyzed using flow cytometry, and the effector function of T cells was assessed using ELISA. We performed a rechallenge by subcutaneous injection of GL261 cells in the “cured” (>90 days post-orthotopic tumor implantation) and naïve mice.

Results

The mean survival time in the control, anti-Tim-3, anti-CEACAM1, and combined treatment groups was 29.8, 43.4, 42.3, and 86.0 days, respectively, with 80% of the mice in the combined group becoming long-term survivors showing immune memory against glioma cells. Infiltrating CD4⁺ and CD8⁺ T cells increased and immunosuppressive Tregs decreased with the combined therapy, which resulted in a markedly elevated ratio of CD4⁺ and CD8⁺ cells to Tregs. Additionally, plasma IFN-γ and TGF-β levels were upregulated and downregulated, respectively.

Conclusions

Our data indicate that combined blockade of Tim-3 and CEACAM1 generates robust therapeutic efficacy in mice with intracranial tumors, and provides a promising option for GBM immunotherapy.

Identification of IGF-1-enhanced cytokine expressions targeted by miR-181d in glioblastomas via an integrative miRNA/mRNA regulatory network analysis

The insulin-like growth factor (IGF)-1 signaling is relevant in regulating cell growth and cytokine secretions by glioblastomas. MicroRNAs determine the cell fate in glioblastomas. However, relationships between IGF-1 signaling and miRNAs in glioblastoma pathogenesis are still unclear. Our aim was to validate the IGF-1-mediated mRNA/miRNA regulatory network in glioblastomas. Using in silico analyses of mRNA array and RNA sequencing data from The Cancer Genome Atlas (TCGA), we identified 32 core enrichment genes that were highly associated with IGF-1-promoted cytokine-cytokine receptor interactions. To investigate the IGF-1-downregulated miRNA signature, microarray-based approaches with IGF-1-treated U87-MG cells and array data in TCGA were used. Four miRNAs, including microRNA (miR)-9-5p, miR-9-3p, miR-181d, and miR-130b, exhibited an inverse correlation with IGF-1 levels. The miR-181d, that targeted the most IGF-1-related cytokine genes, was significantly reduced in IGF-1-treated glioma cells. Statistical models incorporating both high-IGF-1 and low-miR-181d statuses better predicted poor patient survival, and can be used as an independent prognostic factor in glioblastomas. The C-C chemokine receptor type 1 (CCR1) and interleukin (IL)-1b demonstrated inverse correlations with miR-181d levels and associations with patient survival. miR-181d significantly attenuated IGF-1-upregulated CCR1 and IL-1b gene expressions. These findings demonstrate a distinct role for IGF-1 signaling in glioma progression via miR-181d/cytokine networks.