miR-146a induces apoptosis in neuroblastoma cells by targeting BCL11A

Role of microRNA-146a in cancer development by regulating apoptosis

Despite great advances in diagnostic and treatment options for cancer, like chemotherapy surgery, and radiation therapy it continues to remain a major global health concern. Further research is necessary to find new biomarkers and possible treatment methods for cancer. MicroRNAs (miRNAs), tiny non-coding RNAs found naturally in the body, can influence the activity of several target genes. These genes are often disturbed in diseases like cancer, which perturbs functions like differentiation, cell division, cell cycle, apoptosis and proliferation. MiR-146a is a commonly and widely used miRNA that is often overexpressed in malignant tumors. The expression of miR-146a has been correlated with many pathological and physiological changes in cancer cells, such as the regulation of various cell death paths. It's been established that the control of cell death pathways has a huge influence on cancer progression. To improve our understanding of the interrelationship between miRNAs and cancer cell apoptosis, it's necessary to explore the impact of miRNAs through the alteration in their expression levels. Research has demonstrated that the appearance and spread of cancer can be mitigated by moderating the expression of certain miRNA - a commencement of treatment that presents a hopeful approach in managing cancer. Consequently, it is essential to explore the implications of miR-146a with respect to inducing different forms of tumor cell death, and evaluate its potential to serve as a target for improved chemotherapy outcomes. Through this review, we provide an outline of miR-146a's biogenesis and function, as well as its significant involvement in apoptosis. As well, we investigate the effects of exosomal miR-146a on the promotion of apoptosis in cancer cells and look into how it could possibly help combat chemotherapeutic resistance.

Role of non-coding RNAs in neuroblastoma

Neuroblastoma is known as the most prevalent extracranial malignancy in childhood with a neural crest origin. It has been widely accepted that non-coding RNAs (ncRNAs) play important roles in many types of cancer, including glioma and gastrointestinal cancers. They may regulate the cancer gene network. According to recent sequencing and profiling studies, ncRNAs genes are deregulated in human cancers via deletion, amplification, abnormal epigenetic, or transcriptional regulation. Disturbances in the expression of ncRNAs may act either as oncogenes or as anti-tumor suppressor genes, and can lead to the induction of cancer hallmarks. ncRNAs can be secreted from tumor cells inside exosomes, where they can be transferred to other cells to affect their function. However, these topics still need more study to clarify their exact roles, so the present review addresses different roles and functions of ncRNAs in neuroblastoma.

MiRNA-146a-A Key Player in Immunity and Diseases

miRNA-146a, a single-stranded, non-coding RNA molecule, has emerged as a valuable diagnostic and prognostic biomarker for numerous pathological conditions. Its primary function lies in regulating inflammatory processes, haemopoiesis, allergic responses, and other key aspects of the innate immune system. Several studies have indicated that polymorphisms in miRNA-146a can influence the pathogenesis of various human diseases, including autoimmune disorders and cancer. One of the key mechanisms by which miRNA-146a exerts its effects is by controlling the expression of certain proteins involved in critical pathways. It can modulate the activity of interleukin-1 receptor-associated kinase, IRAK1, IRAK2 adaptor proteins, and tumour necrosis factor (TNF) targeting protein receptor 6, which is a regulator of the TNF signalling pathway. In addition, miRNA-146a affects gene expression through multiple signalling pathways, such as TNF, NF-κB and MEK-1/2, and JNK-1/2. Studies have been carried out to determine the effect of miRNA-146a on cancer pathogenesis, revealing its involvement in the synthesis of stem cells, which contributes to tumourigenesis. In this review, we focus on recent discoveries that highlight the significant role played by miRNA-146a in regulating various defence mechanisms and oncogenesis. The aim of this review article is to systematically examine miRNA-146a's impact on the control of signalling pathways involved in oncopathology, immune system development, and the corresponding response to therapy.

Mutual Regulation of ncRNAs and Chromatin Remodeling Complexes in Normal and Pathological Conditions

Chromatin remodeling is the one of the main epigenetic mechanisms of gene expression regulation both in normal cells and in pathological conditions. In recent years, a growing number of investigations have confirmed that epigenetic regulators are tightly connected and form a comprehensive network of regulatory pathways and feedback loops. Genes encoding protein subunits of chromatin remodeling complexes are often mutated and change their expression in diseases, as well as non-coding RNAs (ncRNAs). Moreover, different mechanisms of their mutual regulation have already been described. Further understanding of these processes may help apply their clinical potential for establishment of the diagnosis, prognosis, and treatment of the diseases. The therapeutic targeting of the chromatin structure has many limitations because of the complexity of its regulation, with the involvement of a large number of genes, proteins, non-coding transcripts, and other intermediary molecules. However, several successful strategies have been proposed to target subunits of chromatin remodeling complexes and genes encoding them, as well as the ncRNAs that regulate the operation of these complexes and direct them to the target gene regions. In our review, we focus on chromatin remodeling complexes and ncRNAs, their mutual regulation, role in cellular processes and potential clinical application.

MicroRNAs as prospective biomarkers, therapeutic targets and pharmaceuticals in neuroblastoma

Neuroblastomas, the most prevalent malignant solid neoplasms of childhood, originate from progenitor cells of the sympathetic nervous system. Their genetic causation is diverse and involves multiple molecular mechanisms. This review highlights multiple roles of microRNA in neuroblastoma pathogenesis and discusses the prospects of harnessing these important natural regulator molecules as biomarkers, therapeutic targets and pharmaceuticals in neuroblastoma.

MicroRNA-92a-3p-mediated inhibition of BCL11A upregulates γ-globin expression and inhibits oxidative stress and apoptosis in erythroid precursor cells

OBJECTIVE

This study attempted to investigate miR-92a-3p expression in peripheral blood of patients with severe β-thalassemia, and the effect and action mechanism of miR-92a-3p on γ-globin expression and oxidative stress in erythroid precursor cells.

METHODS

CD34⁺ hematopoietic progenitor cells (HPCs) were isolated from peripheral blood of healthy volunteers and patients with severe β-thalassemia. The levels of miR-92a-3p, BCL11A, and γ-globin were measured in erythroid precursor cells. High-performance liquid chromatography (HPLC) was used to analyze hemoglobin F (HbF) content. HPCs were induced with erythroid differentiation and erythroid precursor cells were then obtained. The relevance between miR-92a-3p and BCL11A was studied using dual luciferase reporter gene assay, and the correlation between miR-92a-3p and HbF was assayed by Pearson correlation analysis. Reactive oxygen species (ROS), glutathione (GSH), malondialdehyde (MDA), and superoxide dismutase (SOD) in erythroid precursor cells were tested to evaluate oxidative stress. Cell apoptosis was examined by flow cytometry.

RESULTS

Remarkably higher expression of miR-92a-3p was observed in erythroid precursor cells. Increased expression of miR-92a-3p resulted in elevated levels of γ-globin, GSH, and SOD, reduced expression of ROS and MDA, and decreased cell apoptosis. BCL11A was identified as a target of miR-92a-3p and to be downregulated by miR-92a-3p. Moreover, BCL11A knockdown alone increased the expression of γ-globin, SOD and GSH, and repressed the levels of ROS and MDA and cell apoptosis, and the following inhibition of miR-92a-3p changed these patterns.

CONCLUSIONS

Our data indicated that miR-92a-3p might increase γ-globin level and reduce oxidative stress and apoptosis in erythroid precursor cells by downregulating BCL11A.

BCL11A Facilitates Cell Proliferation and Metastasis in Neuroblastoma via Regulating the PI3K/Akt Signaling Pathway

PURPOSE

The study aims to access the value of B-cell lymphoma/leukemia 11A (BCL11A) in the prognosis of patients with neuroblastoma (NB) and to explore its role and possible mechanism in NB.

METHODS

Tumor specimens from 53 children with neuroblastoma were evaluated for the relationship between BCL11A expression level and prognosis of NB patients. Online datasets like SEQC and Asgharzadeh were analyzed to further check out the suppose.The role of BCL11A in the proliferation and migration of NB cells was studied by functional experiments such as CCK8, colony formation, flow cytometry, transwell and wound healing assay after knocking down BCL11A by small interfering RNA (siRNA) in vitro. The protein makers of the potential pathways were tested by western blot.

RESULTS

High expression of BCL11A in NB patients was closely correlated with high-risk and poor prognosis. The proliferation and migration abilities of NB cell lines SK-N-BE(2) and IMR-32 were significantly impaired by silencing BCL11A. Downregulation of BCL11A expression level in NB cells inhibited the epithelial-mesenchymal transition (EMT) process and affected the PI3K/Akt signaling pathway.

CONCLUSION

As a prognostic indicator of survival in NB patients, BCL11A might serve as a potential therapeutic target. BCL11A played a regulatory role in cell proliferation, invasion, and migration in NB, which may be through the PI3K/AKT signaling pathway and induce EMT.

A 16-miRNA Prognostic Model to Predict Overall Survival in Neuroblastoma

Neuroblastoma is the most malignant childhood tumor. The outcome of neuroblastoma is hard to predict due to the limitation of prognostic markers. In our study, we constructed a 16-miRNA prognostic model to predict the overall survival of neuroblastoma patients for early diagnosis. A total of 205 DE miRNAs were screened using RNA sequencing data from GSE121513. Lasso Cox regression analysis generated a 16-miRNA signature consisting of hsa-let-7c, hsa-miR-135a, hsa-miR-137, hsa-miR-146a, hsa-miR-149, hsa-miR-15a, hsa-miR-195, hsa-miR-197, hsa-miR-200c, hsa-miR-204, hsa-miR-302a, hsa-miR-331, hsa-miR-345, hsa-miR-383, hsa-miR-93, and hsa-miR-9star. The concordance index of multivariate Cox regression analysis was 0.9, and the area under the curve (AUC) values of 3-year and 5-year survival were 0.92 and 0.943, respectively. The mechanism was further investigated using the TCGA and GSE90689 datasets. Two miRNA-gene interaction networks were constructed among DEGs from two datasets. Functional analysis revealed that immune-related processes were involved in the initiation and metastasis of neuroblastoma. CIBERSORT and survival analysis suggested that lower CD8 T-cell proportion and higher SPTA1 expressions were related to a better prognosis. Our study demonstrated that the miRNA signature may be useful in prognosis prediction and management improvement.

Comparison of different protocols of RNA preparation from circulating blood for RNA sequencing

OBJECTIVE

Circulating miRNAs have been extensively used in studies of neurological diseases. Thus, methods to extract high quantity total RNA for RNA sequencing (RNA-seq) and real-time quantitative polymerase chain reaction (RT-qPCR) are needed. However, the extraction of sufficient high-quality nucleic acids from circulating blood is difficult. Differences in eccentricity, cryopreservation conditions and extraction methods may affect RNA quantity and quality. Here, we systematically compared six blood-RNA extraction protocols (protocols 1, 2, 3, 4, 5, and 6; see the methods section for details).

RESULTS

Protocol 1 yielded the highest quality and quantity of RNA; protocol 2, protocol 5 and protocol 6 produced RNA of intermediate quality; and protocols 3 and 4 yielded the lowest quality RNA. The RNA integrity number (RIN) for isolated RNA was > 9.0 when protocol 1 or protocol 2 was used, > 8.0 when protocol 5 was used, and > 7.0 when protocol 6 was used; lower values were obtained when protocol 3 or 4 was used. The RNA extracted from circulating blood using protocol 1 was most intact and suitable for RT-qPCR and RNA-seq.

CONCLUSIONS

The quality of RNA extracted from circulating blood is affected by high-speed centrifugation and cryopreservation. Adding an RNA stabilizer during the cryopreservation of circulating blood significantly improved RNA quality and quantity. The quality of extracted RNA from circulating blood is improved when using TRIzol relative to that attained with a commercial kit.

Non-Coding RNAs Participate in the Pathogenesis of Neuroblastoma

Neuroblastoma is one of the utmost frequent neoplasms during the first year of life. This pediatric cancer is believed to be originated during the embryonic life from the neural crest cells. Previous studies have detected several types of chromosomal aberrations in this tumor. More recent studies have emphasized on expression profiling of neuroblastoma samples to identify the dysregulated genes in this type of cancer. Non-coding RNAs are among the mostly dysregulated genes in this type of cancer. Such dysregulation has been associated with a number of chromosomal aberrations that are frequently detected in neuroblastoma. In this study, we explain the role of non-coding transcripts in the malignant transformation in neuroblastoma and their role as biomarkers for this pediatric cancer.

BCL11A: a potential diagnostic biomarker and therapeutic target in human diseases

Transcription factor B-cell lymphoma/leukemia 11A (BCL11A) gene encodes a zinc-finger protein that is predominantly expressed in brain and hematopoietic tissue. BCL11A functions mainly as a transcriptional repressor that is crucial in brain, hematopoietic system development, as well as fetal-to-adult hemoglobin switching. The expression of this gene is regulated by microRNAs, transcription factors and genetic variations. A number of studies have recently shown that BCL11A is involved in β-hemoglobinopathies, hematological malignancies, malignant solid tumors, 2p15-p16.1 microdeletion syndrome, and Type II diabetes. It has been suggested that BCL11A may be a potential prognostic biomarker and therapeutic target for some diseases. In this review, we summarize the current research state of BCL11A, including its biochemistry, expression, regulation, function, and its possible clinical application in human diseases.

Emerging therapeutic targets for neuroblastoma

INTRODUCTION

Neuroblastoma (NB) is the prime cancer of infancy, and accounts for 9% of pediatric cancer deaths. While children diagnosed with clinically stable NB experience a complete cure, those with high-risk disease (HR-NB) do not recover, despite intensive therapeutic strategies. Development of novel and effective targeted therapies is needed to counter disease progression, and to benefit long-term survival of children with HR-NB.

AREAS COVERED

Recent studies (2017-2020) pertinent to NB evolution are selectively reviewed to recognize novel and effective therapeutic targets. The prospective and promising therapeutic targets/strategies for HR-NB are categorized into (a) targeting oncogene-like and/or reinforcing tumor suppressor (TS)-like lncRNAs; (b) targeting oncogene-like microRNAs (miRs) and/or mimicking TS-miRs; (c) targets for immunotherapy; (d) targeting epithelial-to-mesenchymal transition and cancer stem cells; (e) novel and beneficial combination approaches; and (f) repurposing drugs and other strategies in development.

EXPERT OPINION

It is highly unlikely that agents targeting a single candidate or signaling will be beneficial for an HR-NB cure. We must develop efficient drug deliverables for functional targets, which could be integrated and advance clinical therapy. Fittingly, the looming evidence indicated an aggressive evolution of promising novel and integrative targets, development of efficient drugs, and improvised strategies for HR-NB treatment.

MicroRNA-146a Is a Wide-Reaching Neuroinflammatory Regulator and Potential Treatment Target in Neurological Diseases

Progressive functional deterioration and loss of neurons underlies neurological diseases and constitutes an important cause of disability and death worldwide. The causes of various types of neurological diseases often share several critical nerve-related cellular mechanisms and pathological features, particularly the neuroinflammatory response in the nervous system. A rapidly growing body of evidence indicates that various microRNAs play pivotal roles in these processes in neurological diseases and might be viable therapeutic targets. Among these microRNAs, microRNA-146a (miR-146a) stands out due to the rapid increase in recent literature on its mechanistic involvement in neurological diseases. In this review, we summarize and highlight the critical role of miR-146a in neurological diseases. MiR-146a polymorphisms are associated with the risk of neurological disease. Alterations in miR-146a expression levels are crucial events in the pathogenesis of numerous neurological diseases that are spatially and temporally diverse. Additionally, the target genes of miR-146a are involved in the regulation of pathophysiological processes in neurological diseases, particularly the neuroinflammatory response. In summary, miR-146a mainly plays a critical role in neuroinflammation during the progression of neurological diseases and might be a prospective biomarker and therapeutic target. Understanding the mechanisms by which miR-146a affects the neuroinflammatory response in different neurological injuries, different cell types, and even different stages of certain neurological diseases will pave the way for its use as a therapeutic target in neurodegenerative diseases.

The dual role of mir-146a in metastasis and disease progression

OBJECTIVE

MicroRNAs are ribonucleic acids that are single-stranded and endogenous non-coding acids that regulate gene expression in later stages of the translation process by binding to genomic regulatory sites. miR146a is mostly involved in the regulation of inflammatory systems and another process that role in the innate immune system. In the present review, we have focused on the recent acquisitions about the main role played by mir146a in the control of the immune system and tumorigenesis. The main purpose of this review article is to systematically investigate the mir146a and its role in regulating signaling pathways involved in cancer and the immune system as well as its involved therapeutic methods.

METHODS

Systematic search of MEDLINE, Web of Science and Cochrane Library was conducted for all comparative studies from 2000 to 2019 with the limitations of the English language.

RESULTS

For a notable period of time, researchers have mainly focused on the therapeutic mechanisms of mir146a involved in the modulation of inflammatory and anti-inflammatory genes. We found that levels of mir146a expression were associated with cancer cell metastasis as a dual role (Inhibitory and stimulatory roles). The results of various studies also showed that this microRNA has a therapeutic role through its effects on other gene expressions such as NF-kB, SIRT1, TNF- α and IL-1β and leads to disease control.

CONCLUSION

Knowledge about alterations in mir146a regulation will give a better understanding of the molecular basis for various chronic inflammatory diseases and cancers.

MicroRNAs in neuroblastoma tumorigenesis, therapy resistance, and disease evolution

Neuroblastoma (NB) deriving from neural crest cells is the most common extra-cranial solid cancer at infancy. NB originates within the peripheral sympathetic ganglia in adrenal medulla and along the midline of the body. Clinically, NB exhibits significant heterogeneity stretching from spontaneous regression to rapid progression to therapy resistance. MicroRNAs (miRNAs, miRs) are small (19-22 nt in length) non-coding RNAs that regulate human gene expression at the post-transcriptional level and are known to regulate cellular signaling, growth, differentiation, death, stemness, and maintenance. Consequently, the function of miRs in tumorigenesis, progression and resistance is of utmost importance for the understanding of dysfunctional cellular pathways that lead to disease evolution, therapy resistance, and poor clinical outcomes. Over the last two decades, much attention has been devoted to understanding the functional roles of miRs in NB biology. This review focuses on highlighting the important implications of miRs within the context of NB disease progression, particularly miRs’ influences on NB disease evolution and therapy resistance. In this review, we discuss the functions of both the “oncomiRs” and “tumor suppressor miRs” in NB progression/therapy resistance. These are the critical components to be considered during the development of novel miR-based therapeutic strategies to counter therapy resistance.

MicroRNAs in Microglia: How do MicroRNAs Affect Activation, Inflammation, Polarization of Microglia and Mediate the Interaction Between Microglia and Glioma?

The essential roles of microglia in maintaining homeostasis in the healthy brain and contributing to neuropathology are well documented. Emerging evidence suggests that epigenetic modulation regulates microglial behavior in both physiological and pathological conditions. MicroRNAs (miRNAs) are short, non-coding epigenetic regulators that repress target gene expression mostly via binding to 3'-untranslated region (3'-UTR) of mRNA in a Dicer-dependent manner. Dysregulation of certain miRNAs can contribute to microglial hyper-activation, persistent neuroinflammation, and abnormal macrophage polarization in the brain. These abnormal conditions can support the pathogenesis of neurological disorders such as glioma, Alzheimer's disease (AD), amyotrophic lateral sclerosis (ALS), stroke, ischemia, and spinal cord injury (SCI). However, the roles of miRNAs in microglia in health and neurological disease have not been systematically summarized. This review will first report the role of Dicer, a key endoribonulease that is responsible for most miRNA biogenesis in microglia. Second, we will focus on recent research about the function of miRNAs in activation, inflammation and polarization of microglia, respectively. In addition, potential crosstalk between microglia and glioma cells via miRNAs will be discussed in this part. Finally, the role of two essential miRNAs, miR-124, and miR-155, in microglia will be highlighted.