MiR-16-5p is frequently down-regulated in astrocytic gliomas and modulates glioma cell proliferation, apoptosis and response to cytotoxic therapy

Immunogenic cell death mediated TLR3/4-activated MSCs in U87 GBM cell line

Background and aims

Glioblastoma (GBM) is an aggressive primary brain cancer with no promising curative therapies. It has been indicated that MSCs can interact with the tumour microenvironment (TME) through the secretion of soluble mediators regulating intercellular signalling within the TME. TLRs are a multigene family of pattern recognition receptors with evolutionarily conserved regions and are widely expressed in immune and other body cells. MSCs by TLRs can recognize conserved molecular components (DAPMPs and PAPMPs) and activate signalling pathways, which regulate immune and inflammatory responses. MSCs may exert immunomodulatory functions through interaction with their expressed toll-like receptors (TLRs) and exert a protective effect against tumour antigens. As an emerging approach, we aimed to monitor the U87 cell line growth, migration and death markers following specific TLR3/4-primed-MSCs-CMs treatment.

Methods and results

We investigated the phenotypic and functional outcomes of primed-CMs and glioma cell line co-culture following short-term, low-dose TLR3/4 priming. The gene expression profile of target genes, including apoptotic markers and related genes, was analyzed by qRT-PCR. MicroRNA-Seq examined the miRNA expression patterns, and flow cytometry evaluated the cell viability and cycle stages. The results showed significant changes in apoptosis and likely necroptosis-related markers following TLR3/4-primed-MSCs-CMs exposure in the glioma cell line. Notably, we observed a considerable induction of selective pro-apoptotic markers and both the early and late stages of apoptosis in treated U87 cell lines. Additionally, the migration rate of glioma cells significantly decreased following MSCs-CM treatment.

Conclusion

Our findings confirmed that the exposure of TLR3/4-activated-MSCs-CMs with glioma tumour cells possibly changes the immunogenicity of the tumour microenvironment and induces immunogenic programmed cell death. Our results can support the idea that TLR3/4-primed-MSCs can lead to innate immune-mediated cell death and modify tumour cell biology in invasive and metastatic cancers.

LncRNA NDUFA6-DT: A Comprehensive Analysis of a Potential LncRNA Biomarker and Its Regulatory Mechanisms in Gliomas

Gliomas are the most prevalent primary malignant tumors affecting the brain, with high recurrence and mortality rates. Accurate diagnoses and effective treatment challenges persist, emphasizing the need for identifying new biomarkers to guide clinical decisions. Long noncoding RNAs (lncRNAs) hold potential as diagnostic and therapeutic biomarkers in cancer. However, only a limited subset of lncRNAs in gliomas have been explored. Therefore, this study aims to identify lncRNA signatures applicable to patients with gliomas across all grades and explore their clinical significance and potential biological mechanisms. Data used in this study were obtained from TCGA, CGGA, and GEO datasets to identify key lncRNA signatures in gliomas through differential and survival analyses and machine learning algorithms. We examined their associations with the clinical characteristics, gene mutations, diagnosis, and prognosis of gliomas. Functional enrichment analysis was employed to elucidate the potential biological mechanisms associated with these significant lncRNA signatures. We explored competing endogenous RNA (ceRNA) regulatory networks. We found that NDUFA6-DT emerged as a significant lncRNA signature in gliomas, with reduced NDUFA6-DT expression associated with a worse prognosis in gliomas. Nomogram analysis incorporating NDUFA6-DT expression levels exhibited excellent prognostic and predictive capabilities. Functional annotation suggested that NDUFA6-DT might influence immunological responses and synaptic transmission, potentially modifying glioma initiation and progression. The associated ceRNA network revealed the possible presence of the NDUFA6-DT-miR-455-3p-YWHAH/YWHAG axis in low-grade glioma (LGG) and glioblastoma multiforme (GBM), regulating the PI3K-AKT signaling pathway and influencing glioma cell survival and apoptosis. We believe that NDUFA6-DT is a novel lncRNA linked to glioma diagnosis and prognosis, potentially becoming a pivotal biomarker for glioma.

MicroRNAs in adult high-grade gliomas: Mechanisms of chemotherapeutic resistance and their clinical relevance

Notorious for its high mortality rate, the current standard treatment for high-grade gliomas remains a challenge. This is largely due to the complex heterogeneity of the tumour coupled with dysregulated molecular mechanisms leading to the development of drug resistance. In recent years, microRNAs (miRNAs) have been considered to provide important information about the pathogenesis and prognostication of gliomas. miRNAs have been shown to play a specific role in promoting oncogenesis and regulating resistance to anti-glioma therapeutic agents through diverse cellular mechanisms. These include regulation of apoptosis, alterations in drug efflux pathways, enhanced activation of oncogenic signalling pathways, Epithelial-Mesenchymal Transition-like process (EMT-like) and a few others. With this knowledge, upregulation or inhibition of selected miRNAs can be used to directly affect drug resistance in glioma cells. Moreover, the clinical use of miRNAs in glioma management is becoming increasingly valuable. This comprehensive review delves into the role of miRNAs in drug resistance in high-grade gliomas and underscores their clinical significance. Our analysis has identified a distinct cluster of oncogenic miRNAs (miR-9, miR-21, miR-26a, miR-125b, and miR-221/222) and tumour suppressive miRNAs (miR-29, miR-23, miR-34a-5p, miR 181b-5p, miR-16-5p, and miR-20a) that consistently emerge as key players in regulating drug resistance across various studies. These miRNAs have demonstrated significant clinical relevance in the context of resistance to anti-glioma therapies. Additionally, the clinical significance of miRNA analysis is emphasised, including their potential to serve as clinical biomarkers for diagnosing, staging, evaluating prognosis, and assessing treatment response in gliomas.

Differential microRNA Expression Analysis in Patients with HPV-Infected Ovarian Neoplasms

This study aimed to identify microRNAs (miRNAs) whose expression levels are altered by high-risk human papillomavirus (HR-HPV) infection in women with epithelial ovarian neoplasms. MiRNA expression was quantified by real-time polymerase chain reaction, while HR-HPV DNA was quantified using digital-droplet PCR. Analysis of 11 miRNAs demonstrated significantly lower hsa-miR-25-5p expression in HPV-infected compared to uninfected ovarian tissues (p = 0.0405), while differences in miRNA expression in corresponding serum were statistically insignificant. The expression of hsa-miR-218-5p in ovarian tumors was significantly higher in high-grade serous ovarian carcinoma (HGSOC) cases than in other neoplasms (p = 0.0166). In addition, hsa-miR-218-5p was significantly upregulated, whereas hsa-miR-191-5p was significantly downregulated in tissues with stage III/IV FIGO (p = 0.0009 and p = 0.0305, respectively). Using unsupervised clustering, we identified three unique patient groups with significantly varied frequencies of HPV16/18-positive samples and varied miRNA expression profiles. In multivariate analysis, high expression of hsa-miR-16-5p was an independent prognostic factor for poor overall survival (p = 0.0068). This preliminary analysis showed the changes in miRNA expression in ovarian neoplasms during HPV infection and those collected from HGSOCs or patients with advanced disease. This prospective study can provide new insights into the pathogenesis of ovarian neoplasms and host-virus interactions.

Dissecting the functional significance of HSP90AB1 and other heat shock proteins in countering glioblastomas and ependymomas using omics analysis and drug prediction using virtual screening

Heat shock proteins (HSPs) are the evolutionary family of proteins that are highly conserved and present widely in various organisms and play an array of important roles and cellular functions. Currently, very few or no studies are based on the systematic analysis of the HSPs in Glioblastoma (GBMs) and ependymomas. We performed an integrated omics analysis to predict the mutual regulatory differential HSP signatures that were associated with both glioblastoma and ependymomas. Further, we explored the various common dysregulated biological processes operating in both the tumors, and were analyzed using functional enrichment, gene ontology along with the pathway analysis of the predicted HSPs. We established an interactome network of protein-protein interaction (PPIN) to identify the hub HSPs that were commonly associated with GBMs and ependymoma. To understand the mutual molecular mechanism of the HSPs in both malignancies, transcription factors, and miRNAs overlapping with both diseases were explored. Moreover, a transcription factor-miRNAs-HSPs coregulatory network was constructed along with the prediction of potential candidate drugs that were based on perturbation-induced gene expression analysis. Based on the RNA-sequencing data, HSP90AB1 was identified as the most promising target among other predicted HSPs. Finally, the ranking of the drugs was arranged based on various drug scores. In conclusion, this study gave a spotlight on the mutual targetable HSPs, biological pathways, and regulatory signatures associated with GBMs and ependymoma with an improved understanding of crosstalk involved. Additionally, the role of therapeutics was also explored against HSP90AB1. These findings could potentially be able to explain the interplay of HSP90AB1 and other HSPs within these two malignancies.

MicroRNAs miR-16 and miR-519 control meningioma cell proliferation via overlapping transcriptomic programs shared with the RNA-binding protein HuR

Introduction

Meningiomas are the most common type of primary central nervous system tumors. In about 80% cases, these tumors are benign and grow very slowly, but the remainder 20% can unlock higher proliferation rates and become malignant. In this study we examined two miRs, miR-16 and miR-519, and evaluated their role in tumorigenesis and cell growth in human meningioma.

Methods

A cohort of 60 intracranial grade 1 and grade 2 human meningioma plus 20 healthy meningeal tissues was used to quantify miR-16 and miR-519 expressions. Cell growth and dose-response assays were performed in two human meningioma cell lines, Ben-Men-1 (benign) and IOMM-Lee (aggressive). Transcriptomes of IOMM-lee cells were measured after both miR-mimics transfection, followed by integrative bioinformatics to expand on available data.

Results

In tumoral tissues, we detected decreased levels of miR-16 and miR-519 when compared with arachnoid cells of healthy patients (miR-16: P=8.7e-04; miR-519: P=3.5e-07). When individually overexpressing these miRs in Ben-Men-1 and IOMM-Lee, we observed that each showed reduced growth (P<0.001). In IOMM-Lee cell transcriptomes, downregulated genes, among which ELAVL1/HuR (miR-16: P=6.1e-06; miR-519:P=9.38e-03), were linked to biological processes such as mitotic cell cycle regulation, pre-replicative complex, and brain development (FDR<1e-05). Additionally, we uncovered a specific transcriptomic signature of miR-16/miR-519-dysregulated genes which was highly enriched in HuR targets (>6-fold; 79.6% of target genes).

Discussion

These results were confirmed on several public transcriptomic and microRNA datasets of human meningiomas, hinting that the putative tumor suppressor effect of these miRs is mediated, at least in part, via HuR direct or indirect inhibition.

Let-7c-5p Represses Cisplatin Resistance of Lung Adenocarcinoma Cells by Targeting CDC25A

Cisplatin broadly functions as a routine treatment for lung adenocarcinoma (LUAD) patients. However, primary and acquired cisplatin resistances frequently occur in the treatment of LUAD patients, seriously affecting the therapeutic effect of cisplatin in patients. We intended to illustrate the impact of let-7c-5p/cell division cycle 25A (CDC25A) axis on cisplatin resistance in LUAD. Expression of let-7c-5p and CDC25A was analyzed via quantitative real-time polymerase chain reaction. The interaction between the two was verified by dual-luciferase reporter detection. For detecting half-maximal inhibitory concentration value of cisplatin in LUAD cells and cell proliferation, we separately applied Cell Counting Kit-8 and colony formation assays. Furthermore, we measured cell apoptosis and cell cycle distribution via flow cytometry, as well as cell cycle-related protein expression via Western blot. Let-7c-5p was evidently downregulated in LUAD, while CDC25A was remarkably upregulated. Let-7c-5p upregulation arrested LUAD cells to proliferate, stimulated cell apoptosis, and arrested cell cycle in G0/G1 phase, thus enhancing sensitivity of LUAD cells to cisplatin. In terms of mechanism, CDC25A was directly targeted by let-7c-5p, and the influence of let-7c-5p overexpression on LUAD proliferation, apoptosis, cell cycle, and cisplatin resistance could be reversed by CDC25A upregulation. Let-7c-5p improved sensitivity of LUAD cells to cisplatin by modulating CDC25A, and let-7c-5p/CDC25A axis was an underlying target for the intervention of LUAD cisplatin resistance.

The Prospective Application of Melatonin in Treating Epigenetic Dysfunctional Diseases

In the past, different human disorders were described by scientists from the perspective of either environmental factors or just by genetically related mechanisms. The rise in epigenetic studies and its modifications, i.e., heritable alterations in gene expression without changes in DNA sequences, have now been confirmed in diseases. Modifications namely, DNA methylation, posttranslational histone modifications, and non-coding RNAs have led to a better understanding of the coaction between epigenetic alterations and human pathologies. Melatonin is a widely-produced indoleamine regulator molecule that influences numerous biological functions within many cell types. Concerning its broad spectrum of actions, melatonin should be investigated much more for its contribution to the upstream and downstream mechanistic regulation of epigenetic modifications in diseases. It is, therefore, necessary to fill the existing gaps concerning corresponding processes associated with melatonin with the physiological abnormalities brought by epigenetic modifications. This review outlines the findings on melatonin’s action on epigenetic regulation in human diseases including neurodegenerative diseases, diabetes, cancer, and cardiovascular diseases. It summarizes the ability of melatonin to act on molecules such as proteins and RNAs which affect the development and progression of diseases.

Micro RNA-640 Targeting SLIT1 Enhances Glioma Radiosensitivity by Restraining the Activation of Wnt/β-Catenin Signaling Pathway

Purpose: The purpose of this study was to analyze the effects of miR-640–SLIT1 axis and the Wnt/β-catenin signaling pathway on radiosensitivity of glioma cells.

Methods: Relative expressions of miR-640 and slit guidance ligand 1 (SLIT1) in glioma tissues and glioma cell lines U251 and A172 were detected using RT-qPCR. The cell lines were transfected with si-SLIT1 or miR-640 inhibitor to study the radiosensitivity of glioma cells. We detected cell activity using CCK-8 assay, cell migration using wound healing assay, cell invasion using transwell assay, and apoptosis using caspase-3 assay.

Results: SLIT1 was upregulated in glioma tissues and cell lines, and inversely correlated with radiation sensitivity. Its knockdown reduced radioresistance, migration, and invasion, but increased apoptosis in U251 and A17 cells. Loss of miR-640 activity upregulated SLIT1, Wnt, and β-catenin protein expression, whereas it inhibited p-GSK-3β protein levels in U251 and A17 cells. These results suggest that miR-640 mediates the radiosensitivity of glioma cells through SLIT1 and the Wnt/β-catenin signaling pathway.

Conclusion: The miR-640–SLIT1 axis that regulates the Wnt/β-catenin signaling pathway is a possible therapeutic option for the effective treatment of glioma in combination with radiotherapy.

Plasma MicroRNA Signature Panel Predicts the Immune Response After Antiretroviral Therapy in HIV-Infected Patients

Background

Approximately 10–40% of people with human immunodeficiency virus (HIV) infection are unable to obtain successful improvements in immune function after antiretroviral therapy (ART). These patients are at greater risk of developing non-acquired immunodeficiency syndrome (AIDS)-related conditions, with the accompanying increased morbidity and mortality. Discovering predictive biomarkers can help to identify patients with a poor immune response earlier and provide new insights into the mechanisms of this condition.

Methods

A total of 307 people with HIV were enrolled, including 110 immune non-responders (INRs) and 197 immune responders (IRs). Plasma samples were taken before ART, and quantities of plasma microRNAs (miRNAs) were determined using reverse transcriptase-quantitative polymerase chain reaction (RT-qPCR). Candidate biomarkers were established through four phases: discovery, training, validation, and blinded test. Binary logistic regression was used to analyze the combined predictive capacity of the identified miRNAs. The effect of one miRNA, miR-16-5p, on T cell function was assessed in vitro.

Results

Expression of five miRNAs (miR-580, miR-627, miR-138-5p, miR-16-5p, and miR-323-3p) was upregulated in the plasma of INRs compared with that in IRs. Expression of these miRNAs was negatively correlated with both CD4⁺ T cell counts and the increase in the proportion of CD4⁺ T cells after one year of ART. These five miRNAs were combined in a predictive model, which could effectively identify INRs or IRs. Furthermore, we found that miR-16-5p inhibits CD4⁺ T cell proliferation by regulating calcium flux.

Conclusion

We established a five-miRNA panel in plasma that accurately predicts poor immune response after ART, which could inform strategies to reduce the incidence of this phenomenon and improve the clinical management of these patients.

FIN56, a novel ferroptosis inducer, triggers lysosomal membrane permeabilization in a TFEB-dependent manner in glioblastoma

Objective: To explore the anti-tumor effect of FIN56, a novel ferroptosis inducer, on glioblastoma and its underlying mechanisms. Methods: Two human glioblastoma cell lines, LN229 and U118 were applied in this study. Anti-tumor effect was measured by CCK-8 assay, EdU assay and cell cycle analysis. Fluorescent probes, immunofluorescence, plasmid transfection, shRNA knocking out, reverse transcription PCR, western blot analysis, and transmission electron microscopy were used to study the underlying mechanisms. At last, a subcutaneous nude mice model was used to study the anti-tumor effect of FIN56 in vivo. The GraphPad Prism software program was applied for statistical analysis. Results: FIN56 decreased cell viability, inhibited cell proliferation and caused cell cycle arrest on LN229 and U118 cells. Further study showed that FIN56 induced ferroptosis and induced lysosomal membrane permeabilization in a ferroptosis and transfactor EB dependent manner. Animal study demonstrated that FIN56 inhibited glioma growth and caused ferroptosis in vivo. Conclusion: FIN56 is a promising anti-tumor compound.

MicroRNAs: emerging driver of cancer perineural invasion

The perineural invasion (PNI), which refers to tumor cells encroaching on nerve, is a clinical feature frequently occurred in various malignant tumors, and responsible for postoperative recurrence, metastasis and decreased survival. The pathogenesis of PNI switches from 'low-resistance channel' hypothesis to 'mutual attraction' theory between peripheral nerves and tumor cells in perineural niche. Among various molecules in perineural niche, microRNA (miRNA) as an emerging modulator of PNI through generating RNA-induced silencing complex (RISC) to orchestrate oncogene and anti-oncogene has aroused a wide attention. This article systematically reviewed the role of microRNA in PNI, promising to identify new biomarkers and offer cancer therapeutic targets.

[Development and functional validation of a nano-delivery system of miR-16/polypeptide targeting ovarian cancer cells]

OBJECTIVE

To develop a nano-delivery system for targeted delivery of miR-16/polypeptide for enhancing cisplatin sensitivity of ovarian cancer.

OBJECTIVE

R9-SS-R9 and cRGD-R9-SS-R9 peptides were synthesized and self-assembled with miR-16 molecules to form a nano-delivery system. The stability, particle size, potential and morphology of the nanoparticles were determined by agarose gel electrophoresis, particle size potentiometer and transmission electron microscopy. CCK-8 assay was used to assess the toxicity of the polypeptides in ovarian cancer cells. Stem loop qRT-PCR and living cell imaging were used to verify the uptake efficiency and intracellular distribution of the nanoparticles. Flow cytometry and Western blotting were performed to verify the effect of the nanoparticles for enhancing cisplatin sensitivity of ovarian cancer cells and explore the possible mechanism.

OBJECTIVE

R9-SS-R9/miR-16 and cRGD-R9-SS-R9/miR-16 nanoparticles were successfully prepared. The nanoparticles, with a particle size below 150 nm, a dispersity index less than 0.1 and a potential of about 40 mV, showed a good serum stability. The polypeptide material had no obvious cytotoxicity. The miR-16/polypeptide nanoparticles could be efficiently absorbed by human ovarian cancer cells and were distributed in the cytoplasm. The nanoparticles significantly increased the intracellular expression level of miR-16 (P < 0.001) and decreased the expression of Bcl-2 and Chk-1 proteins in ovarian cancer cells, thus enabling miR-16 to promote apoptosis and enhance cisplatin sensitivity of the cells.

OBJECTIVE

We successfully prepared a miR-16/polypeptide nano-delivery system for targeted delivery of miR-16 to ovarian cancer cells for enhancing cisplatin sensitivity of the cancer cells.

lncRNA TUG1 inhibits the cancer stem cell‑like properties of temozolomide‑resistant glioma cells by interacting with EZH2

Temozolomide (TMZ) is currently one of the first-line drugs used for the treatment of high-grade gliomas. However, TMZ resistance results in unsatisfactory therapeutic effects in gliomas. Cancer stem cells (CSCs) have recently been determined to serve a pivotal regulatory role in tumor metastasis, recurrence and chemoresistance. In addition, numerous reports have shown that long non-coding RNAs (lncRNAs) exert an essential role in the occurrence and development of tumors, and can be used as biomarkers for tumor diagnosis and treatment. Among them, studies have revealed that taurine upregulated gene 1 (TUG1) exhibits an important regulatory effect on the malignant biological behavior of glioma cells. Moreover, it has been reported that enhancer of Zeste homolog 2 polycomb repressive complex subunit 2 (EZH2) promotes tumorigenesis, including in glioma. However, the underlying mechanism of the interaction of TUG1 and EZH2 with CSCs of glioma remains elusive, and thus requires further clarification. The present study aimed to explore the role of TUG1 and EZH2 in TMZ resistance in glioma. Cell Counting Kit-8, colony formation,sphere formation and Annexin V-FITC/PI assays were used to detect the proliferation, clone formation efficiency, stemness and apoptosis of TMZ-resistant glioma cells. Xenograft tumor assay was used to detect the effect of TUG1 on the tumorigenesis of TMZ-resistant glioma cells. The present findings demonstrated that TUG1 exhibited a low expression in glioma cells, while EZH2 expression was the opposite. Moreover, it was observed that A172/TMZ cells possessed higher CSCs-like properties compared with parent cells, and that TUG1 and EZH2 were abnormally expressed in A172/TMZ cells. Knockdown of TUG1 or overexpression of EZH2 promoted A172/TMZ cell proliferation and CSCs-like properties, as well as inhibited their apoptosis, thereby enhancing the TMZ resistance of A172/TMZ cells. Furthermore, it was found that TUG1 alleviated the TMZ resistance of A172/TMZ cells by inhibiting EZH2 expression. Of note, overexpression of TUG1 inhibited the tumorigenicity of A172/TMZ cells by downregulating EZH2 expression in vivo. Collectively, the present study demonstrated that TUG1 served an essential regulatory role in TMZ resistance of gliomas.

Long intergenic non-coding RNA 00473 promotes proliferation and migration of gastric cancer via the miR-16-5p/CCND2 axis and by regulating AQP3

Gastric cancer (GC) is one of the most common malignancies worldwide, but its molecular mechanisms remain unclear. Increasing evidence indicates that long non-coding RNAs (LncRNAs) play a pivotal role in various cancers recently. Our present study focused on exploring the function of long intergenic non-coding RNA 00473 (LINC00473) in GC. In this study, we found that LINC00473 expression was aberrantly increased in tumor tissues compared with the paired para-cancerous tissues. The expression of high LINC00473 in GC was notably correlated with a higher risk of lymphatic metastasis, a higher incidence of vascular cancer embolus, and advanced TNM stage. Further experiments showed that the overexpression of LINC00473 could promote the proliferation and metastasis of GC cells both in vitro and in vivo. The apoptosis of GC cells increased significantly by the decrease of LINC00473. Mechanistically, LINC00473 could sponge miR-16-5p in the cytoplasm and relieve its suppression of CCND2. Moreover, AQP3 was found to be a significant downstream target gene for LINC00473 through RNA transcriptome sequencing, as demonstrated by qRT-PCR and western blot. Overexpression of LINC00473 can partially reverse the effects of AQP3 decrease on GC proliferation and metastasis. LINC00473 regulated AQP3 expression through CREB was confirmed by western blot. Our research indicates that LINC00473/miR-16-5p/CCND2 axis plays a role in the proliferation of GC and modulates AQP3 to influence GC cell metastasis, making it a potential therapeutic target for GC.

LINC00649 Facilitates the Cellular Process of Bladder Cancer Cells via Signaling Axis miR-16-5p/JARID2

Bladder cancer (BC), as one of the most common cancers around the world, begins in the inner side of the bladder and is inclined to spread to the remaining parts of the body. Extensive documents have shown that long noncoding RNAs function as stimuli in various cancer types. With regard to LINC00649, there is limited investigation on its role previously. In our research, we discovered that LINC00649 was considerably highly expressed in BC cells and the lack of LINC00649 would cause inactivity in cellular proliferation, migration, and invasion. miR-16-5p turned out to be competitively incorporated by LINC00649 in the upstream or JARID2 downstream. In BC cells, LINC00649 was found to bind with miR-16-5p to increase the expression of JARID2. Overly expressed JARID2 was found to reverse the LINC00649 shortage-mediated suppressive impacts on the cellular process of BC cells. Concisely, it was the first study on the molecular mechanism of LINC00649 in BC. This work detected that LINC00649 enhanced cell proliferation, migration, and invasion of BC cells by acting as a sponge of miR-16-5p and upregulating JARID2, providing novel insight into understating BC.

microRNAs Mediated Regulation of the Ribosomal Proteins and its Consequences on the Global Translation of Proteins

Ribosomal proteins (RPs) are mostly derived from the energy-consuming enzyme families such as ATP-dependent RNA helicases, AAA-ATPases, GTPases and kinases, and are important structural components of the ribosome, which is a supramolecular ribonucleoprotein complex, composed of Ribosomal RNA (rRNA) and RPs, coordinates the translation and synthesis of proteins with the help of transfer RNA (tRNA) and other factors. Not all RPs are indispensable; in other words, the ribosome could be functional and could continue the translation of proteins instead of lacking in some of the RPs. However, the lack of many RPs could result in severe defects in the biogenesis of ribosomes, which could directly influence the overall translation processes and global expression of the proteins leading to the emergence of different diseases including cancer. While microRNAs (miRNAs) are small non-coding RNAs and one of the potent regulators of the post-transcriptional gene expression, miRNAs regulate gene expression by targeting the 3' untranslated region and/or coding region of the messenger RNAs (mRNAs), and by interacting with the 5' untranslated region, and eventually finetune the expression of approximately one-third of all mammalian genes. Herein, we highlighted the significance of miRNAs mediated regulation of RPs coding mRNAs in the global protein translation.

Tanshinone IIA Suppresses Glioma Cell Proliferation, Migration and Invasion Both in vitro and in vivo Partially Through miR-16-5p/Talin-1 (TLN1) Axis

Background

Tanshinone IIA (TIIA) is one of the active constituents derived from the rhizome of Danshen, a traditional Chinese herbal. Recently, microRNAs (miRNAs) have been suggested to be associated with the anticancer role of TIIA. However, it remains vague of the interaction between miRNAs and TIIA in glioma, a common aggressive brain tumor in humans.

Methods

Expression of miRNA (miR)-16-5p and talin-1 (TLN1) was detected using reverse transcription-quantitative polymerase chain reaction and Western blotting. Cell proliferation, migration and invasion were assessed with cell viability assay, transwell assay, Western blotting, and xenograft tumor experiment. The target binding between miR-16-5p and TLN1 was confirmed by dual-luciferase reporter assay and RNA pull-down assay.

Results

TIIA treatment inhibited cell viability, migration and invasion, and decreased Cyclin D1, matrix metalloproteinase (MMP)-9 and Vimentin expression in glioma T98G and A172 cells both in vitro and in vivo. Thus, TIIA induced anti-glioma role, wherein miR-16-5p was upregulated and TLN1 was downregulated. Moreover, silencing miR-16-5p could abate TIIA-mediated suppression on glioma cell proliferation, migration and invasion in vitro and in vivo. TLN1 overexpression also exerted tumor-promoting effect in TIIA-treated T98G and A172 cells. Mechanically, miR-16-5p could regulate TLN1 expression via target binding, and depleting TLN1 could counteract the inhibitory effect of miR-16-5p knockdown on the curative effect of TIIA in T98G and A172 cells.

Conclusion

TIIA exerted the anti-proliferation, anti-migration and anti-invasion role in glioma cells both in vitro and in vivo partially through regulating miR-16-5p/TLN1 axis.

The lncRNA MEG3/miR-16-5p/VGLL4 regulatory axis is involved in etoposide-induced senescence of tumor cells

BACKGROUND

The senescence of tumor cells is an important tumor suppressor mechanism. The present study aimed to investigate the role of long non-coding RNA (lncRNA) MEG3 (maternally expressed gene 3) in the senescence process of tumor cells and its potential molecular mechanism by competitively binding with microRNA miR-16-5p to regulate the expression of VGLL4 (encoding vestigial like family member 4).

METHODS

We used etoposide to construct senescence models of tumor cells. The degree of cellular senescence was detected by senescence-associated β-galactosidase, cell cycle and senescence-associated secretory phenotype. The expression of lncRNA MEG3, miR-16-5p and VGLL4 in senescent or non-senescent cells was evaluated using a quantitative real-time reverse transcriptase-PCR (qRT-PCR) or western blotting. Dual luciferase reporter assays were used to detect the binding of miR-16-5p to lncRNA MEG3 and VGLL4. The mRNA and protein expression levels of senescence-related markers (p53, p21 and p16) were detected using qRT-PCR or western blotting.

RESULTS

Compared to the control group, the expression of lncRNA MEG3 and VGLL4 was significantly up-regulated in senescent cells. Knockdown of lncRNA MEG3 and VGLL4 reduced the degree of senescence and the expression of p21 and p16. lncRNA MEG3 interfered with the expression of miR-16-5p in senescent A549 and MCF-7 cells. The expression of VGLL4 was regulated by miR-16-5p in senescent A549 and MCF-7 cells. lncRNA MEG3 participated in the senescent progress of tumor cells induced by etoposide via the miR-16-5p/VGLL4 axis.

CONCLUSIONS

The present study has confirmed the regulatory role of the lncRNA MEG3/miR-16-5p/VGLL4 axis in the low-dose etoposide-induced tumor cell senescence model, which has potential clinical application with respect to treating malignant tumors.

Comprehensive analysis of a long non-coding RNA-associated competing endogenous RNA network in glioma

Long non-coding RNAs (lncRNAs) can act as competing endogenous RNAs (ceRNAs), interacting with microRNAs (miRNAs) and playing an important role in tumor progression. However, the role of lncRNA-mediated ceRNAs in glioma remains largely unknown. The present study aimed to identify novel lncRNAs and their associated function in glioma. RNA sequencing and corresponding clinical data from patients with glioma were obtained from The Cancer Genome Atlas. A total of 598 glioma tissues and 5 normal brain tissues were analyzed in the present study. The differentially expressed (DE) lncRNAs, mRNAs and miRNAs were identified using R packages and were used to construct a ceRNA network. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses were performed to investigate the biological functions of the DEmRNAs. Kaplan-Meier curve analysis was performed to investigate the association between DElncRNA expression and patient outcome. A total of 752 DElncRNAs, 2,079 DEmRNAs and 113 DEmiRNAs were identified between glioma and normal tissues. A lncRNA-miRNA-mRNA ceRNA network consisting of 61 lncRNAs, 12 miRNAs and 92 mRNAs was constructed. Survival analysis indicated that 36 DElncRNAs, 72 DEmRNAs and 3 DEmiRNAs were associated with overall survival in patients with glioma. The present study identified novel lncRNAs associated with survival prognosis and may facilitate further investigation of lncRNA-mediated ceRNA regulatory mechanisms in glioma.

A Novel DNA Methylation-Based Signature Can Predict the Responses of MGMT Promoter Unmethylated Glioblastomas to Temozolomide

Glioblastoma (GBM) is the most malignant glioma, with a median overall survival (OS) of 14–16 months. Temozolomide (TMZ) is the first-line chemotherapy drug for glioma, but whether TMZ should be withheld from patients with GBMs that lack O6-methylguanine-DNA methyltransferase (MGMT) promoter methylation is still under debate. DNA methylation profiling holds great promise for further stratifying the responses of MGMT promoter unmethylated GBMs to TMZ. In this study, we studied 147 TMZ-treated MGMT promoter unmethylated GBM, whose methylation information was obtained from the HumanMethylation27 (HM-27K) BeadChips (n = 107) and the HumanMethylation450 (HM-450K) BeadChips (n = 40) for training and validation, respectively. In the training set, we performed univariate Cox regression and identified that 3,565 CpGs were significantly associated with the OS of the TMZ-treated MGMT promoter unmethylated GBMs. Functional analysis indicated that the genes corresponding to these CpGs were enriched in the biological processes or pathways of mitochondrial translation, cell cycle, and DNA repair. Based on these CpGs, we developed a 31-CpGs methylation signature utilizing the least absolute shrinkage and selection operator (LASSO) Cox regression algorithm. In both training and validation datasets, the signature identified the TMZ-sensitive GBMs in the MGMT promoter unmethylated GBMs, and only the patients in the low-risk group appear to benefit from the TMZ treatment. Furthermore, these identified TMZ-sensitive MGMT promoter unmethylated GBMs have a similar OS when compared with the MGMT promoter methylated GBMs after TMZ treatment in both two datasets. Multivariate Cox regression demonstrated the independent prognostic value of the signature in TMZ-treated MGMT promoter unmethylated GBMs. Moreover, we also noticed that the hallmark of epithelial–mesenchymal transition, ECM related biological processes and pathways were highly enriched in the MGMT unmethylated GBMs with the high-risk score, indicating that enhanced ECM activities could be involved in the TMZ-resistance of GBM. In conclusion, our findings promote our understanding of the roles of DNA methylation in MGMT umethylated GBMs and offer a very promising TMZ-sensitivity predictive signature for these GBMs that could be tested prospectively.

Inhibition of miR-16 enhances the sensitivity of fibroblast-like synovial cells to methotrexate by restraining MDR1/P-gp expression via NF-κB pathway

MicroRNAs (miRNAs) are demonstrated to contribute to the regulation of drug resistance in a number of diseases. Nevertheless, little is known about the role and the underlying mechanism of miR-16 in rheumatoid arthritis (RA) methotrexate resistance. In this study, we firstly examined the miR-16 expression in the serum and synovial fluid from RA patients who were unresponsive to methotrexate monotherapy (UR-MTX patients) and responsive RA patients (R-MTX patients). Secondly, the miR-16 expression was measured in both fibroblast-like synovial cells (FLS) and methotrexate resistance RA-FLS cells (FLS-MTX). FLS cells used in this study were isolated from synovial tissue specimens obtained from patients with RA who underwent total joint replacement. FLS-MTX cells were conducted by gradually increasing the concentration of methotrexate in the medium. The construction of FLS-MTX cells was confirmed by 3-(4,5)-dimethylthiahiazo(-z-y1)-3,5-di-phenytetrazoliumromide (MTT) assay. Thirdly, in order to further investigate the role of miR-16 in FLS-MTX cells, we introduced miR-16 inhibitor into FLS-MTX cells to knockdown the expression of miR-16, used fluorescence quantitative PCR to detect the inhibition efficiency. The effects of miR-16 inhibition on cell viability, cell cycle arrest and apoptosis in FLS-MTX cells were monitored with MTT and flow cytometry analysis, respectively. And the regulation of miR-16 on P-glycoprotein (P-gp) was performed using qRT-PCR, western blotting, and immunofluorescence staining. Fourthly, ammonium pyrrolidinedithiocarbamate (PDTC), a NF-κB pathway inhibitor, was applied to verify the mechanism by which miR-16 involved in to regulate the P-gp expression, and thus contributing to the methotrexate resistance in FLS-MTX cells. MiR-16 was upregulated in the in serum and synovial fluid from UR-MTX patients as well as in FLS-MTX cells. Inhibition of miR-16 re-sensitized the FLS-MTX cells to methotrexate by suppressing the cell viability, cell promoting cycle arrest at G0/G1 phase and enhancing apoptosis. Knockdown of miR-16 significantly reduced MDR1 mRNA expression and P-gp protein expression in FLS-MTX cells. Furthermore, inhibition of NF-κB pathway by PDTC reinforced the effect of miR-16 knockdown on P-gp expression, cell viability, cell cycle arrest and apoptosis. In conclusion, our study illustrated that inhibition of miR-16 in FLS-MTX cells alleviated methotrexate resistance by inhibiting MDR1/P-gp expression through inactivation of the NF-κB pathway.

MicroRNAs (miRNAs) are demonstrated to contribute to the regulation of drug resistance in a number of diseases.