miR-146b-5p functions as a tumor suppressor by targeting TRAF6 and predicts the prognosis of human gliomas

TRAF6 enhances PD-L1 expression through YAP1-TFCP2 signaling in melanoma

Immunotherapy represented by programmed cell death protein 1 (PD-1)/programmed death ligand 1 (PD-L1) monoclonal antibodies has led tumor treatment into a new era. However, the low overall response rate and high incidence of drug resistance largely damage the clinical benefits of existing immune checkpoint therapies. Recent studies correlate the response to PD-1/PD-L1 blockade with PD-L1 expression levels in tumor cells. Hence, identifying molecular targets and pathways controlling PD-L1 protein expression and stability in tumor cells is a major priority. In this study, we performed a Stress and Proteostasis CRISPR interference screening to identify PD-L1 positive modulators. Here, we identified TRAF6 as a critical regulator of PD-L1 in melanoma cells. As a non-conventional E3 ubiquitin ligase, TRAF6 is inclined to catalyze the synthesis and linkage of lysine-63 (K63) ubiquitin which is related to the stabilization of substrate proteins. Our results showed that suppression of TRAF6 expression down-regulates PD-L1 expression on the membrane surface of melanoma cells. We then used in vitro and in vivo assays to investigate the biological function and mechanism of TRAF6 and its downstream YAP1/TFCP2 signaling in melanoma. TRAF6 stabilizes YAP1 by K63 poly-ubiquitination modification, subsequently promoting the formation of YAP1/TFCP2 transcriptional complex and PD-L1 transcription. Inhibition of TRAF6 by Bortezomib enhanced cytolytic activity of CD8+ T cells by reduction of endogenous PD-L1. Notably, Bortezomib enhances anti-tumor immunity to an extent comparable to anti-PD-1 therapies with no obvious toxicity. Our findings reveal the potential of inhibiting TRAF6 to stimulate internal anti-tumor immunological effect for TRAF6-PD-L1 overexpressing cancers.

Sevoflurane Suppresses Glioma Cell Proliferation, Migration, and Invasion Both In Vitro and In Vivo Partially Via Regulating KCNQ1OT1/miR-146b-5p/STC1 Axis

Background: Sevoflurane (Sev), a volatile anesthetic agent, is widely used in neurosurgery for anesthesia maintenance, accompanied with antitumor activity postanesthesia in multiple human cancers, including glioma. However, the molecular mechanism of Sev in glioma is largely unclear, including associated informative noncoding RNAs, such as long noncoding RNAs (lncRNA) and microRNAs (miRNAs). Methods: Expression of lncRNA KCNQ1 opposite strand/antisense transcript 1 (KCNQ1OT1), miRNA (miR)-146b-5p, and stanniocalcin-1 (STC1) was measured by real-time quantitative polymerase chain reaction and Western blotting. Cell proliferation, apoptosis, migration, and invasion in vitro were examined by 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay, fluorescence-activated cell sorting method, and transwell assays, respectively. Tumor growth in vivo was determined by xenograft models. The direct interaction between genes was confirmed by dual-luciferase reporter assay. Results: Sev enhanced apoptotic rate, but inhibited cell viability, migration, and invasion abilities of human glioma A172 and U251 cells in vitro, as well as tumor growth inhibition in vivo. The tumor-suppressive role of Sev in glioma was accompanied with downregulated KCNQ1OT1 and STC1, and upregulated miR-146b-5p. Overexpression of KCNQ1OT1 through transfection reversed, while KCNQ1OT1 silencing aggravated the antitumor role of Sev in A172 and U251 cells. Moreover, KCNQ1OT1-mediated tumor-promoting activity in A172 and U251 cells under Sev treatment was abrogated by miR-146b-5p restoration or STC1 deletion. Essentially, KCNQ1OT1 could positively regulate STC1 by acting as miR-146b-5p decoy. Conclusion: KCNQ1OT1 knockdown mediated the role of Sev in glioma cell proliferation, apoptosis, migration, and invasion both in vitro and in vivo through miR-146b-5p/STC1 pathway.

Use of microRNAs as Diagnostic, Prognostic, and Therapeutic Tools for Glioblastoma

Glioblastoma (GB) is the most aggressive and common type of cancer within the central nervous system (CNS). Despite the vast knowledge of its physiopathology and histology, its etiology at the molecular level has not been completely understood. Thus, attaining a cure has not been possible yet and it remains one of the deadliest types of cancer. Usually, GB is diagnosed when some symptoms have already been presented by the patient. This diagnosis is commonly based on a physical exam and imaging studies, such as computed tomography (CT) and magnetic resonance imaging (MRI), together with or followed by a surgical biopsy. As these diagnostic procedures are very invasive and often result only in the confirmation of GB presence, it is necessary to develop less invasive diagnostic and prognostic tools that lead to earlier treatment to increase GB patients' quality of life. Therefore, blood-based biomarkers (BBBs) represent excellent candidates in this context. microRNAs (miRNAs) are small, non-coding RNAs that have been demonstrated to be very stable in almost all body fluids, including saliva, serum, plasma, urine, cerebrospinal fluid (CFS), semen, and breast milk. In addition, serum-circulating and exosome-contained miRNAs have been successfully used to better classify subtypes of cancer at the molecular level and make better choices regarding the best treatment for specific cases. Moreover, as miRNAs regulate multiple target genes and can also act as tumor suppressors and oncogenes, they are involved in the appearance, progression, and even chemoresistance of most tumors. Thus, in this review, we discuss how dysregulated miRNAs in GB can be used as early diagnosis and prognosis biomarkers as well as molecular markers to subclassify GB cases and provide more personalized treatments, which may have a better response against GB. In addition, we discuss the therapeutic potential of miRNAs, the current challenges to their clinical application, and future directions in the field.

Epi-miRNAs: Modern mediators of methylation status in human cancers

Methylation of the fundamental macromolecules, DNA/RNA, and proteins, is remarkably abundant, evolutionarily conserved, and functionally significant in cellular homeostasis and normal tissue/organism development. Disrupted methylation imprinting is strongly linked to loss of the physiological equilibrium and numerous human pathologies, and most importantly to carcinogenesis, tumor heterogeneity, and cancer progression. Mounting recent evidence has documented the active implication of miRNAs in the orchestration of the multicomponent cellular methylation machineries and the deregulation of methylation profile in the epigenetic, epitranscriptomic, and epiproteomic levels during cancer onset and progression. The elucidation of such regulatory networks between the miRNome and the cellular methylation machineries has led to the emergence of a novel subclass of miRNAs, namely "epi-miRNAs" or "epi-miRs." Herein, we have summarized the existing knowledge on the functional role of epi-miRs in the methylation dynamic landscape of human cancers and their clinical utility in modern cancer diagnostics and tailored therapeutics. This article is categorized under: RNA in Disease and Development > RNA in Disease.

Exosomal miR-146b-5p derived from cancer-associated fibroblasts promotes progression of oral squamous cell carcinoma by downregulating HIPK3

OBJECTIVES

Cancer-associated fibroblasts (CAFs) are vital constituents of the tumor microenvironment (TME) and play a predominant role in oral squamous cell carcinoma (OSCC) progression. We aimed to investigate the effect and mechanism of exosomal miR-146b-5p derived from CAFs on the malignant biological behavior of OSCC.

MATERIALS AND METHODS

Illumina small RNA (sRNA) sequencing was conducted to determine the differential expression patterns of microRNAs (miRNAs) in exosomes derived from CAFs and normal fibroblasts (NFs). Transwell and cell counting kit-8 (CCK-8) assays and xenograft tumor models in nude mice were used to investigate the effect of CAF exosomes and miR-146b-p on the malignant biological behavior of OSCC. Reverse transcription quantitative real-time PCR (qRT-PCR), luciferase reporter, western blotting (WB) and immunohistochemistry assays were employed to investigate the underlying mechanisms involved in CAF exosomes that promote OSCC progression.

RESULTS

We demonstrated that CAF-derived exosomes were taken up by OSCC cells and enhanced the proliferation, migration, and invasion ability of OSCC. Compared with NFs, the expression of miR-146b-5p was increased in exosomes and their parent CAFs. Further studies showed that the decreased expression of miR-146b-5p inhibited the proliferation, migration and invasion ability of OSCC cells in vitro and the growth of OSCC cells in vivo. Mechanistically, miR-146b-5p overexpression led to the suppression of HIKP3 by directly targeting the 3'-UTR of HIPK3, as confirmed by luciferase assay. Reciprocally, HIPK3 knockdown partially reversed the inhibitory effect of the miR-146b-5p inhibitor on the proliferation, migration, and invasion ability of OSCC cells and restored their malignant phenotype.

CONCLUSIONS

Our results revealed that CAF-derived exosomes contained higher levels of miR-146b-5p than NFs, and miR-146b-5p overexpression in exosomes promoted the malignant phenotype of OSCC by targeting HIPK3. Therefore, inhibiting exosomal miR-146b-5p secretion may be a promising therapeutic modality for OSCC.

Interfering with the Ubiquitin-Mediated Regulation of Akt as a Strategy for Cancer Treatment

The serine/threonine kinase Akt modulates the functions of numerous substrates, many of them being involved in cell proliferation and growth, metabolism, angiogenesis, resistance to hypoxia and migration. Akt is frequently deregulated in many types of human cancers, its overexpression or abnormal activation being associated with the increased proliferation and survival of cancer cells. A promising avenue for turning off the functionality of Akt is to either interfere with the K63-linked ubiquitination that is necessary for Akt membrane recruitment and activation or increase the K48-linked polyubiquitination that aims to target Akt to the proteasome for its degradation. Recent evidence indicates that targeting the ubiquitin proteasome system is effective for certain cancer treatments. In this review, the functions and roles of Akt in human cancer will be discussed, with a main focus on molecules and compounds that target various elements of the ubiquitination processes that regulate the activation and inactivation of Akt. Moreover, their possible and attractive implications for cancer therapy will be discussed.

Comprehensive analysis of RNA-binding protein SRSF2-dependent alternative splicing signature in malignant proliferation of colorectal carcinoma

Aberrant expression of serine/arginine-rich splicing factor 2 (SRSF2) can lead to tumorigenesis, but its molecular mechanism in colorectal cancer is currently unknown. Herein, we found SRSF2 to be highly expressed in human colorectal cancer (CRC) samples compared with normal tissues. Both in vitro and in vivo, SRSF2 significantly accelerated the proliferation of colon cancer cells. Using RNA-seq, we screened and identified 33 alternative splicing events regulated by SRSF2. Knockdown of SLMAP-L or CETN3-S splice isoform could suppress the growth of colon cancer cells, predicting their role in malignant proliferation of colon cancer cells. Mechanistically, the in vivo crosslinking immunoprecipitation assay demonstrated the direct binding of the RNA recognition motif of SRSF2 protein to SLMAP and CETN3 pre-mRNAs. SRSF2 activated the inclusion of SLMAP alternative exon 24 by binding to constitutive exon 25, while SRSF2 facilitated the exclusion of CETN3 alternative exon 5 by binding to neighboring exon 6. Knockdown of SRSF2, its splicing targets SLMAP-L, or CETN3-S caused colon cancer cells to arrest in G1 phase of the cell cycle. Rescue of SLMAP-L or CETN3-S splice isoform in SRSF2 knockdown colon cancer cells could effectively reverse the inhibition of cell proliferation by SRSF2 knockdown through mediating cell cycle progression. Importantly, the percentage of SLMAP exon 24 inclusion increased and CETN3 exon 5 inclusion decreased in CRC samples compared to paired normal samples. Collectively, our findings identify that SRSF2 dysregulates colorectal carcinoma proliferation at the molecular level of splicing regulation and reveal potential splicing targets in CRC patients.

Mesenchymal stem cell-derived exosomes as new tools for delivery of miRNAs in the treatment of cancer

Although ongoing medical research is working to find a cure for a variety of cancers, it continues to be one of the major causes of death worldwide. Chemotherapy and immunotherapy, as well as surgical intervention and radiation therapy, are critical components of cancer treatment. Most anti-cancer drugs are given systemically and distribute not just to tumor tissues but also to normal tissues, where they may cause side effects. Furthermore, because anti-cancer drugs have a low delivery efficiency, some tumors do not respond to them. As a result, tumor-targeted drug delivery is critical for improving the safety and efficacy of anti-cancer treatment. Exosomes are microscopic extracellular vesicles that cells produce to communicate with one another. MicroRNA (miRNA), long non-coding RNA (lncRNA), small interfering RNA (siRNA), DNA, protein, and lipids are among the therapeutic cargos found in exosomes. Recently, several studies have focused on miRNAs as a potential therapeutic element for the treatment of cancer. Mesenchymal stem cells (MSC) have been known to have angiogenic, anti-apoptotic, anti-inflammatory and immunomodulatory effects. Exosomes derived from MSCs are gaining popularity as a non-cellular alternative to MSC-based therapy, as this method avoids unwanted lineage differentiation. Therefore more research have focused on transferring miRNAs to mesenchymal stem cells (MSC) and targeting miRNA-loaded exosomes to cancer cells. Here, we initially gave an overview of the characteristics and potentials of MSC as well as the use of MSC-derived exosomes in cancer therapy. Finally, we emphasized the utilization of MSC-derived exosomes for miRNA delivery in the treatment of cancer.

Circulating miRNA profiles in mice plasma following flavonoid intake

BACKGROUND

Polyphenols, including flavonoids, have been the focus of numerous studies that have revealed diverse health benefits. MicroRNAs (miRNAs) constitute a class of small non-coding RNAs that function as posttranscriptional regulators of gene expression. miRNAs can be detected in the blood and these so-called circulating miRNAs are potential biomarkers of various diseases. This study aimed to explore circulating miRNAs in plasma as a means to predict the biological effects of functional food ingredients.

METHODS AND RESULTS

We used miRNA microarray analysis to compare plasma miRNA levels in mice orally administered three flavonoids (daidzein, quercetin, and delphinidin). Several miRNAs were differentially expressed in plasma from mice in each treatment group compared with the vehicle-treated group. The plasma levels of miR-25-5p, miR-146b-5p, and miR-501-3p were increased in the flavonoid-treated and the plasma levels of miR-148b-3p, miR-669e-5p, and miR-3962 were decreased.

CONCLUSIONS

Our findings suggested that flavonoids alter miRNA expression in plasma and identified promising plasma miRNAs for assessing the functionality of flavonoids.

The Role of microRNAs in Multidrug Resistance of Glioblastoma

Simple Summary

Glioblastoma (GBM) is one of the most malignant types of central nervous system tumor which accounts for more than 60% of all brain tumors in adults. Owing to poor prognosis and drug resistance of most GBM, it is urged to further develop the diagnosis and treatment strategies. The aim of this article is to highlight the roles of some functional microRNAs in the diagnosis and treatment of drug-resistant GBM. Besides, we suggest effective treatment strategies based on the expression profiles of these effective miRNAs to provide an alternative solution to deal with this cancer.

Abstract

Glioblastoma (GBM) is an aggressive brain tumor that develops from neuroglial stem cells and represents a highly heterogeneous group of neoplasms. These tumors are predominantly correlated with a dismal prognosis and poor quality of life. In spite of major advances in developing novel and effective therapeutic strategies for patients with glioblastoma, multidrug resistance (MDR) is considered to be the major reason for treatment failure. Several mechanisms contribute to MDR in GBM, including upregulation of MDR transporters, alterations in the metabolism of drugs, dysregulation of apoptosis, defects in DNA repair, cancer stem cells, and epithelial–mesenchymal transition. MicroRNAs (miRNAs) are a large class of endogenous RNAs that participate in various cell events, including the mechanisms causing MDR in glioblastoma. In this review, we discuss the role of miRNAs in the regulation of the underlying mechanisms in MDR glioblastoma which will open up new avenues of inquiry for the treatment of glioblastoma.

Enhanced Cognition and Neurogenesis in miR-146b Deficient Mice

The miR-146 family consists of two microRNAs (miRNAs), miR-146a and miR-146b, which are both known to suppress a variety of immune responses. Here in this study, we show that miR-146b is abundantly expressed in neuronal cells, while miR-146a is mainly expressed in microglia and astroglia of adult mice. Accordingly, miR-146b deficient (Mir146b-/-) mice exhibited anxiety-like behaviors and enhanced cognition. Characterization of cellular composition of Mir146b-/- mice using flow cytometry revealed an increased number of neurons and a decreased abundancy of astroglia in the hippocampus and frontal cortex, whereas microglia abundancy remained unchanged. Immunohistochemistry showed a higher density of neurons in the frontal cortex of Mir146b-/- mice, enhanced hippocampal neurogenesis as evidenced by an increased proliferation, and survival of newly generated cells with enhanced maturation into neuronal phenotype. No microglial activation or signs of neuroinflammation were observed in Mir146b-/- mice. Further analysis demonstrated that miR-146b deficiency is associated with elevated expression of glial cell line-derived neurotrophic factor (Gdnf) mRNA in the hippocampus, which might be at least in part responsible for the observed neuronal expansion and the behavioral phenotype. This hypothesis is partially supported by the positive correlation between performance of mice in the object recognition test and Gdnf mRNA expression in Mir146b-/- mice. Together, these results show the distinct function of miR-146b in controlling behaviors and provide new insights in understanding cell-specific function of miR-146b in the neuronal and astroglial organization of the mouse brain.

Sevoflurane inhibits the malignant phenotypes of glioma through regulating miR-146b-5p/NFIB axis

PURPOSE

Sevoflurane is a common used inhaled anesthetic that was reported to regulate the progression of multiple cancers. Here, we aimed to investigate the function and regulatory mechanism underlying sevoflurane in glioma cells.

METHODS

A172 and U251 cells were treated with different concentrations of sevoflurane. Colony formation, EdU satining and 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT), flow cytometry, and transwell assays were performed to evaluate cell proliferation, apoptosis, migration and invasion, respectively. Circ_VCAN, microRNA-146b-5p (miR-146b-5p) and nuclear factor I B (NFIB) expression levels were assessed by real-time quantitative PCR (RT-qPCR) or western blot. Bioinformatics analysis and dual-luciferase reporter assay were applied to evaluate the correlation between miR-146b-5p and circ_VCAN or NFIB. A xenograft glioma mice model was established to verify the effect of sevoflurane on tumor growth in vivo.

RESULTS

Sevoflurane (Sev) inhibited proliferation, migration, invasion, and elevated apoptosis of A172 and U251 cells. Sevoflurane treatment inhibited the expression of circ_VCAN and NFIB, but elevated the expression of miR-146b-5p in glioma cells. Overexpression of circ_VCAN alleviated the inhibition effects of sevoflurane on the malignant phenotypes of glioma in vitro and in vivo. Besides, miR-146b-5p is a target of circ_VCAN and negatively regulated NFIB expression. Overexpression of miR-146b-5p partly reversed the effects of circ_VCAN in Sev-treated glioma cells. Furthermore, miR-146b-5p deletion enhanced glioma progression in sevoflurane treated glioma cells by targeting NFIB. Moreover, circ_VCAN could upregulate NFIB expression by sponging miR-146b-5p in Sev-treated glioma cells.

CONCLUSION

Sevoflurane alleviated proliferation, migration and invasion, but enhanced apoptosis of glioma cells through regulating circ_VCAN/miR-146b-5p/NFIB axis.

miR‑146b‑5p promotes colorectal cancer progression by targeting TRAF6

Increasing evidence highlights the multiple roles of microRNAs (miRs) in the tumorigenesis of colorectal cancer (CRC); however, the molecular mechanism, particularly the target of miR-146b-5p in CRC has not been fully elucidated. The present study aimed to elucidate the influence of miR-146b-5p via regulating tumor necrosis factor receptor-associated factor 6 (TRAF6) in CRC. The expression levels of miR-146b-5p and TRAF6 in CRC tissue and cells were determined by reverse transcription quantitative PCR and western blotting. Binding between miR-146b-5p and TRAF6 was examined using a dual luciferase reporter gene assay. The impact of miR-146b-5p and TRAF6 on proliferation and migration of CRC cells was determined using Cell Counting Kit-8 and Transwell assays, respectively. An animal model of CRC was established to determine the carcinogenic effect of the miR-146b-5p-TRAF6 axis. The results demonstrated that miR-146b-5p was highly expressed in CRC tissue samples compared with in normal adjacent tissue samples and in CRC cells compared with in the normal NCM460 cell line, whereas TRAF6 was expressed at low levels. Overexpression of miR-146b-5p decreased TRAF6 expression in CRC HT29 and SW620 cells. miR-146b-5p targeted and inhibited TRAF6 expression in CRC cells. Furthermore, transfection with a miR-146b-5p mimic promoted the proliferation, migration and invasion of CRC cells and tumor growth; however, these effects were abolished by TRAF6 overexpression. Transfection with a miR-146b-5p inhibitor suppressed the proliferation of CRC cells. Taken together, the results from the present study demonstrated that miR-146b-5p could enhance the initiation and tumorigenesis of CRC by targeting TRAF6. These results will help elucidate the mechanisms underlying CRC development and will facilitate the development of targeted therapy for CRC.

Potential role of microRNAs as biomarkers in human glioblastoma: a mini systematic review from 2015 to 2020

Glioblastoma (GBM) is the most common, aggressive and malignant type of glioma, with poor prognosis, despite advances in medical knowledge and technology. It's known that some microRNAs (miRNAs) can be dysregulated and associated with tumors. We aim to investigate miRNAs that may have a role as potential biomarkers in human glioblastoma. A search was performed using PubMed, LILACS and SCIELO databases to find papers from 2015 to 2020, related to human in vitro and ex vivo data. From 99 articles, 10 were eligible and 13 dysregulated miRNAs were found with description of regulation, target(s), pathway(s) and mechanism(s). The miRNAs of interest were found and seem to be involved in development and progression of glioblastoma and used as target therapies. Understanding the mechanisms in which those miRNAs are involved and their role in epigenetic pathways that lead to cancer, as well as their potential in clinical application, may improve GBM clinical outcome (CRD42020182706, 07/10/2020, retrospectively registered).

LncRNA NEAT1 Regulates Infantile Pneumonia by Sponging miR-146b

This study designed to investigate the potential role of lncRNA NEAT1/miR-146b in infantile pneumonia. In this study, 58 children with pneumonia and 58 healthy children collected for routine examination from December 2016 to January 2019. The lncRNA NEAT1 and miR-146b expression levels were detected by qPCR in both groups. The pneumonia model was established by inducing human embryonic lung fibroblasts HFL1 with LPS, and then transfected with lncRNA NEAT1 inhibition and miR-146b over-expression vector to observe the effect on cell viability and apoptosis after induction. Starbase predicted the binding site between lncRNA NEAT1 and miR-146b, and the targeted relationship between them was detected by dual luciferase reporter gene. The relative expression of lncRNA NEAT1 in serum of infantile pneumonia was up-regulated. Knocking down lncRNA NEAT1 promotes cell growth and reduces apoptosis in LPS-induced HFL1 cells. Results showed that the fluorescence activity of lncRNA NEAT1 obviously reduced when combined with miR-146b. In conclusion, the relative expression of miR-146b in serum of infantile pneumonia decreased, and over-expressing it could promote LPS-induced cell viability and reduce apoptosis. Taken together, this study demonstrated that the lncRNA NEAT1 regulates infantile pneumonia by sponging miR-146b.

miR‑146b‑5p inhibits tumorigenesis and metastasis of gallbladder cancer by targeting Toll‑like receptor 4 via the nuclear factor‑κB pathway

Gallbladder cancer (GBC) is a carcinoma of the biliary tract, which is common in developing countries and is associated with a high fatality rate. The aim of the present study was to investigate the mechanisms underlying the occurrence and development of GBC. A decrease in the expression of miR‑146b‑5p and an increase in the expression of its target gene Toll‑like receptor 4 (TLR4) were first observed in GBC tissues. Further study demonstrated that an increase in TLR4 expression caused by a decrease in miR‑146b‑5p expression led to activation of nuclear factor (NF)‑κB signaling. GBC cells were cultured in vitro, and it was observed that overexpression of miR‑146b‑5p effectively inhibited their viability, proliferation, migration and invasion, and increased their apoptosis. Using a BALB/c nude mouse xenograft model, it was demonstrated that overexpression of miR‑146b‑5p was sufficient to reduce tumor volume and alleviate pathological characteristics. Overall, the results of the present study indicated that the decrease in the expression of miR‑146b‑5p increased TLR4 expression and indirectly activated the NF‑κB signaling pathway, thereby regulating the development of GBC.

Versatile knowledge guided network inference method for prioritizing key regulatory factors in multi-omics data

Constantly decreasing costs of high-throughput profiling on many molecular levels generate vast amounts of multi-omics data. Studying one biomedical question on two or more omic levels provides deeper insights into underlying molecular processes or disease pathophysiology. For the majority of multi-omics data projects, the data analysis is performed level-wise, followed by a combined interpretation of results. Hence the full potential of integrated data analysis is not leveraged yet, presumably due to the complexity of the data and the lacking toolsets. We propose a versatile approach, to perform a multi-level fully integrated analysis: The Knowledge guIded Multi-Omics Network inference approach, KiMONo (https://github.com/cellmapslab/kimono). KiMONo performs network inference by using statistical models for combining omics measurements coupled to a powerful knowledge-guided strategy exploiting prior information from existing biological sources. Within the resulting multimodal network, nodes represent features of all input types e.g. variants and genes while edges refer to knowledge-supported and statistically derived associations. In a comprehensive evaluation, we show that our method is robust to noise and exemplify the general applicability to the full spectrum of multi-omics data, demonstrating that KiMONo is a powerful approach towards leveraging the full potential of data sets for detecting biomarker candidates.

Comprehensive Analysis of Correlations in the Expression of miRNA Genes and Immune Checkpoint Genes in Bladder Cancer Cells

Personalised medicine is the future and hope for many patients, including those with cancers. Early detection, as well as rapid, well-selected treatment, are key factors leading to a good prognosis. MicroRNA mediated gene regulation is a promising area of development for new diagnostic and therapeutic methods, crucial for better prospects for patients. Bladder cancer is a frequent neoplasm, with high lethality and lacking modern, advanced therapeutic modalities, such as immunotherapy. MicroRNAs are involved in bladder cancer pathogenesis, proliferation, control and response to treatment, which we summarise in this perspective in response to lack of recent review publications in this field. We further performed a correlation-based analysis of microRNA and gene expression data in bladder cancer (BLCA) TCGA dataset. We identified 27 microRNAs hits with opposite expression profiles to genes involved in immune response in bladder cancer, and 24 microRNAs hits with similar expression profiles. We discuss previous studies linking the functions of these microRNAs to bladder cancer and assess if they are good candidates for personalised medicine therapeutics and diagnostics. The discussed functions include regulation of gene expression, interplay with transcription factors, response to treatment, apoptosis, cell proliferation and angiogenesis, initiation and development of cancer, genome instability and tumour-associated inflammatory reaction.

CASC9 plays a role in salivary adenoid cystic carcinoma in vitro by upregulation of ACLY

OBJECTIVE

The study was designed to explore the role of cancer susceptibility candidate 9 (CASC9) in salivary adenoid cystic carcinoma (SACC) (SACC-83 and SACC-LM) cell malignant phenotypes.

METHODS

Colony formation assay was used to measure cell proliferation. Transwell assay was used to detect cell migration and invasion. Flow cytometry analysis was applied to determine cell cycle distribution and apoptosis. FISH assay revealed the subcellular location of CASC9.

RESULTS

Downregulation of CASC9 inhibited SACC cell proliferation, migration, and invasion, led to cell arrest at G0/G1 phase, and facilitated cell apoptosis. In mechanism, CASC9 bound with microRNA 146b-5p (miR-146b-5p) and negatively modulated miR-146b-5p expression. MiR-146b-5p directly targeted 3' untranslated region of ATP-Citrate Lyase (ACLY) to degrade ACLY in SACC cells. CASC9 upregulated ACLY expression through competitively binding with miR-146b-5p. Furthermore, rescue assays indicated that ACLY overexpression counteracted the effects triggered by CASC9 knockdown on cell proliferation, migration, invasion, and apoptosis in SACC cells.

CONCLUSION

CASC9 facilitated the malignant phenotypes of SACC cells by the regulation of the miR-146b-5p/ACLY axis. These findings might lay foundation for SACC research.

miR-29a-5p Regulates the Proliferation, Invasion, and Migration of Gliomas by Targeting DHRS4

Gliomas are the most common malignant primary brain tumors in adults and exhibit a spectrum of aberrantly aggressive phenotypes. MicroRNAs (miRNAs) play a regulatory role in various cancers, including gliomas; however, their specific roles and mechanisms have not been fully investigated. Studies have indicated that miR-29a is a tumor-suppressive miRNA, but the data are limited. In this study, we investigated the role of miR-29a-5p in glioma and further explored its underlying mechanisms. On the basis of bioinformatics, dehydrogenase/reductase 4 (DHRS4) was considered a potential target of miR-29a-5p and was also found to be highly expressed in gliomas in our experiments. Moreover, with a luciferase reporter assay, DHRS4 was found to be a target gene of miR-29a-5p and to be correlated with glioma proliferation, invasion, and migration in our in vivo and in vitro experiments. Simultaneously, we observed that the knockdown of DHRS4 rescued the downregulation of glioma proliferation, invasion, and migration caused by treatment with a mir-29a-5p inhibitor. The present findings demonstrate that miR-29a-5p suppresses cell proliferation, invasion, and migration by targeting DHRS4, and DHRS4 may be a potential new oncogene and prognostic factor in gliomas.

The relationship between TRAF6 and tumors

Tumor necrosis factor receptor (TNFR)-related factors (TRAFs) are important linker molecules in the tumor necrosis factor superfamily (TNFSF) and the Toll-like/interleukin-1 receptor (TLR/ILR) superfamily. There are seven members: TRAF1-TRAF7, among those members, tumor necrosis factor receptor-associated factor 6 (TRAF6) is upregulated in various tumors, which has been related to tumorigenesis and development. With the in-depth study of the relationship between TRAF6 and different types of tumors, TRAF6 has oncogenic characteristics involved in tumorigenesis, tumor development, invasion, and metastasis through various signaling pathways, therefore, targeting TRAF6 has provided a novel strategy for tumor treatment. This review summarizes and analyzes the role of TRAF6 in tumorigenesis and tumor development in combination with the current research on TRAF6 and tumors.

Molecular and Cellular Complexity of Glioma. Focus on Tumour Microenvironment and the Use of Molecular and Imaging Biomarkers to Overcome Treatment Resistance

This review highlights the importance and the complexity of tumour biology and microenvironment in the progression and therapy resistance of glioma. Specific gene mutations, the possible functions of several non-coding microRNAs and the intra-tumour and inter-tumour heterogeneity of cell types contribute to limit the efficacy of the actual therapeutic options. In this scenario, identification of molecular biomarkers of response and the use of multimodal in vivo imaging and in particular the Positron Emission Tomography (PET) based molecular approach, can help identifying glioma features and the modifications occurring during therapy at a regional level. Indeed, a better understanding of tumor heterogeneity and the development of diagnostic procedures can favor the identification of a cluster of patients for personalized medicine in order to improve the survival and their quality of life.

LncRNA NEAT1 accelerates renal mesangial cell injury via modulating the miR-146b/TRAF6/NF-κB axis in lupus nephritis

Although growing advances have been made in the regulation of lupus nephritis recently, lupus nephritis is still one of the major causes of death in SLE patients and the pathogenesis remains largely unknown. Therefore, exploring the pathological mechanisms is urgently needed for designing and developing novel therapeutic strategies for lupus nephritis. Human renal mesangial cells (HRMCs) were transfected with sh-NEAT1, miR-146b mimic, pcDNA-NEAT1, miR-146b inhibitor, or sh-TRAF6 to modify their expression. Lipopolysaccharide (LPS) was used to induce inflammatory injury. Cell viability was examined with CCK8. Apoptosis was determined by flow cytometry and Hoechst staining. qRT-PCR and western blot were used to analyze gene expression. The secretion of inflammatory cytokines was examined with ELISA. The bindings of NEAT1 with miR-146b and miR-146b with TRAF6 were tested by dual-luciferase reporter assay. NEAT1 was upregulated in LPS-treated HRMCs. Both the knockdown of NEAT1 and TRAF6 suppressed the LPS-induced inflammatory injury in HRMCs. NEAT1 directly targeted miR-146b to control miR-146b-mediated regulation of TRAF6 expression in HRMCs. NEAT1 promoted the expression of TRAF6 via targeting miR-146b to accelerate the LPS-mediated renal mesangial cell injury in HRMCs. Moreover, TRAF6 activated the NF-κB signaling in HRMCs. NEAT1 accelerated renal mesangial cell injury via directly targeting miR-146b, promoting the expression of TRAF6, and activating the NF-κB signaling in lupus nephritis. Our investigation elucidated novel pathological mechanisms and provided potential therapeutic targets for lupus nephritis.

Downregulation of miR‑193a‑3p via targeting cyclin D1 in thyroid cancer

Thyroid cancer (TC) is a frequently occurring malignant tumor with a rising steadily incidence. microRNA (miRNA/miR)‑193a‑3p is an miRNA that is associated with tumors, playing a crucial role in the genesis and progression of various cancers. However, the expression levels of miR‑193a‑3p and its molecular mechanisms in TC remain to be elucidated. The present study aimed to probe the expression of miR‑193a‑3p and its clinical significance in TC, including its underlying molecular mechanisms. Microarray and RNA sequencing data gathered from three major databases, specifically Gene Expression Omnibus (GEO), ArrayExpress and The Cancer Genome Atlas (TCGA) databases, and the relevant data from the literature were used to examine miR‑193a‑3p expression. Meta‑analysis was also conducted to evaluate the association between clinicopathological parameters and miR‑193a‑3p in 510 TC and 59 normal samples from the TCGA database. miRWalk 3.0, and the TCGA and GEO databases were used to predict the candidate target genes of miR‑193a‑3p. Gene Ontology, Kyoto Encyclopedia of Genes and Genomes and protein‑protein interaction network enrichment analyses were conducted by using the predicted candidate target genes to investigate the underlying carcinogenic mechanisms. A dual luciferase assay was performed to validate the targeting regulatory association between the most important hub gene cyclin D1 (CCND1) and miR‑193a‑3p. miR‑193a‑3p expression was considerably downregulated in TC compared with in the non‑cancer controls (P<0.001). The area under the curve of the summary receiver operating characteristic was 0.80. Downregulation of miR‑193a‑3p was also significantly associated with age, sex and metastasis (P=0.020, 0.044 and 0.048, respectively). Bioinformatics analysis indicated that a low miR‑193a‑3p expression may augment CCND1 expression to affect the biological processes of TC. In addition, CCND1, as a straightforward target, was validated through a dual luciferase assay. miR‑193a‑3p and CCND1 may serve as prognostic biomarkers of TC. Finally, miR‑193a‑3p may possess a crucial role in the genesis and progression of TC by altering the CCND1 expression.

The novel chromatin architectural regulator SND1 promotes glioma proliferation and invasion and predicts the prognosis of patients

BACKGROUND

Upregulation of staphylococcal nuclease domain-containing protein 1 (SND1) is a common phenomenon in different human malignant tissues. However, little information is available on the underlying mechanisms through which SND1 affects glioma cell proliferation and invasion.

METHODS

SND1, Ras homolog family member A (RhoA), and marker of proliferation Ki-67 (MKI67) were analyzed in 187 gliomas by immunostaining. The correlation between those markers and patients' prognoses was assessed using the Kaplan-Meier estimator. Gene Ontology, chromatin immunoprecipitation, electrophoretic mobility shift assay, and chromosome conformation capture were applied to identify SND1-activated target genes. We also used MTT, colony formation, transwell and orthotopic implantation assays to investigate SND1 function in glioma cell proliferative and invasive activity.

RESULTS

We identified SND1 and RhoA as independent predictors of poor prognosis in glioma patients. SND1 knockdown significantly suppressed the proliferation and invasion of glioma cells. Mechanistically, we discovered that SND1 facilitated malignant glioma phenotypes by epigenetically inducing chromatin topological interaction, which activated downstream RhoA transcription. RhoA sequentially regulated expression of CCND1, CCNE1, CDK4, and CDKN1B and accelerated G1/S phase transition in glioma cell proliferation.

CONCLUSIONS

Our findings identify SND1 as a novel chromatin architectural modifier and promising prognostic indicator for glioma classification and treatment.

Nanoparticle-Based Delivery of Tumor Suppressor microRNA for Cancer Therapy

Improved understanding of microRNA expression and function in cancer has revealed a range of microRNAs that negatively regulate many oncogenic pathways, thus representing potent tumor suppressors. Therapeutic targeting of the expression of these microRNAs to the site of tumors and metastases provides a promising avenue for cancer therapy. To overcome challenges associated with microRNA degradation, transient expression and poor targeting, novel nanoparticles are being developed and employed to shield microRNAs for tumor-targeted delivery. This review focuses on studies describing a variety of both natural and synthetic nanoparticle delivery vehicles that have been engineered for tumor-targeted delivery of tumor suppressor microRNAs in vivo.

The stress-activated protein kinase pathway and the expression of stanniocalcin-1 are regulated by miR-146b-5p in papillary thyroid carcinogenesis

Papillary thyroid cancer (PTC) is the most common type of thyroid cancer. Deciphering the pathophysiological mechanisms that contribute to PTC development is essential to the discovery of optimal diagnostic and therapeutic approaches. MiR-146b-5p has been identified as a cancer-associated microRNA highly up-regulated in PTC. This study explores the hypothesis that miR-146b-5p contributes to papillary thyroid carcinogenesis through regulation of cell signaling pathways in a manner that overcomes the cellular growth suppressive events and provides survival advantage. The effect of miR-146b-5p inhibition on major cancer related signaling pathways and expression of Stanniocalcin-1 (STC1), an emerging molecule associated with stress response and carcinogenesis, was tested in cultured primary thyroid cells using luciferase reporter assays, quantitative real-time PCR, immunofluorescence staining, and flow cytometry. Our results demonstrated that miR-146b-5p inhibits the JNK/AP1 pathway activity and down-regulates the expression of STC-1 in thyroid-cultured cells and in thyroid tissue samples. In the presence of miR-146b-5p, PTC cells were resistant to cell death in response to oxidative stress. This is a novel report that miR-146b-5p directly targets STC1 and regulates the activity of JNK/AP1 pathway. Considering the importance of the JNK/AP1 pathway and STC1 in mediating many physiological and pathological processes like apoptosis, stress response and cellular metabolism, a biological regulator of these pathways would have a great scientific and clinical significance.

Sevoflurane suppresses migration and invasion of glioma cells by regulating miR-146b-5p and MMP16

Background: Glioma is the most common brain tumor with poor prognosis all over the world. Anesthetics have been demonstrated to have important impacts on cell migration and invasion in different cancers. However, the underlying mechanism that allows anesthetics-mediated progression of glioma cells remains elusive. Methods: Sevoflurane (Sev), a class of common anesthetics, was used to expose to U87-MG and U251 cells. The expressions of microRNA-146b-5p (miR-146b-5p) and matrix metallopeptidase 16 (MMP16)were measured by quantitative real-time polymerase chain reaction or western blot. Transfection was performed in glioma cells with miR-146b-5p inhibitor, inhibitor negative control, MMP16 overexpression vector, empty vector, small interfering RNA against MMP16 or scramble. Cell migration and invasion were analyzed by the trans-well assay. The interaction between miR-146b-5p and MMP16 was explored by luciferase activity and RNA immunoprecipitation assays. Results: Sev treatment inhibited migration and invasion of glioma cells. The expression of miR-146b-5p was enhanced and MMP16 protein was decreased in glioma cells after exposure of Sev. Knockdown of miR-146b-5p or overexpression of MMP16 reversed Sev-induced inhibition of migration and invasion of glioma cells. Moreover, MMP16 was indicated as a target of miR-146b-5p and its silencing attenuated the regulatory role of miR-146b-5p abrogationin Sev-treated glioma cells. Conclusion: Sev impeded cell migration and invasion through regulating miR-146b-5p and MMP16 in glioma, indicating a novel theories foundation for the application of anesthetics like Sev in glioma.

Clinical significance of aberrant microRNAs expression in predicting disease relapse/refractoriness to treatment in diffuse large B-cell lymphoma: A meta-analysis

The clinical significance of aberrantly expressed microRNAs in predicting treatment response to chemotherapy in diffuse large B-cell lymphoma patients (DLBCL) remains uncertain. Feasibility of microRNA testing to predict treatment outcome was evaluated. Twenty-two types of aberrantly expressed microRNAs were associated with poor treatment response; pooled hazard ratio (HR) was 2.14 [95%CI:1.78-2.57, P < 0.00001]. DLBCL patients with aberrant expression of miR-155, miR-17/92 clusters, miR-21, miR-224, or miR-146b-5p had a higher risk of treatment resistance or shorter period of disease relapse/progression free survival, with HR = 2.71 (95%CI:1.66-4.42, P < 0.0001), HR = 2.70 (95%CI:1.50-4.85, P = 0.0010), HR = 2.20 (95%CI:1.31-3.69, P = 0.003), HR = 2.07 (95%CI:1.50-2.86, P < 0.00001), HR = 2.26 (95%CI:1.40-3.65, P = 0.0009), respectively. The association between aberrant expression of microRNAs and treatment response appears to be stronger in formalin-fixed-paraffin-embedded tissue (HR = 2.41, 95%CI:1.79-3.25, P < 0.00001) than in fresh-frozen samples (HR = 1.94, 95%CI: 1.22-3.08, P = 0.005) and peripheral blood samples (HR = 1.94, 95%CI:1.53-2.46, P < 0.00001). Mir-155, miR-17/92 clusters, miR-21, miR-224, and mir-146b-5p have value in predicting treatment response to chemotherapy in DLBCL.

Ablation of miR-146b in mice causes hematopoietic malignancy

Excessive and constitutive activation of nuclear factor-κB (NF-κB) leads to abnormal cell proliferation and differentiation, leading to the development of malignant tumors, including lymphoma. MicroRNA 146a (miR-146a) and miR-146b, both of which carry an identical seed sequence, have been shown to contribute to inflammatory diseases and tumors by suppressing the expression of key molecules required for NF-κB activation. However, the functional and physiological differences between miR-146a and miR-146b in disease onset have not been fully elucidated. In this study, we generated miR-146b-knockout (KO) and miR-146a-KO mice by genome editing and found that both strains developed hematopoietic malignancies such as B-cell lymphoma and acute myeloid leukemia during aging. However, the B-cell lymphomas observed in miR-146a- and miR-146b-KO mice were histologically different in their morphology, and the malignancy rate is lower in miR-146b mice than miR-146a mice. Upon mitogenic stimulation, the expression of miR-146a and miR-146b was increased, but miR-146b expression was lower than that of miR-146a. Using a previously developed screening system for microRNA targets, we observed that miR-146a and miR-146b could target the same mRNAs, including TRAF6, and inhibit subsequent NF-κB activity. Consistent with these findings, both miR-146a- and miR-146b-KO B cells showed a high proliferative capacity. Taken together, sustained NF-κB activation in miR-146b KO mice could lead to the development of hematopoietic malignancy with aging.

MiR-146b accelerates osteoarthritis progression by targeting alpha-2-macroglobulin

Osteoarthritis (OA) is an aging-related chronic degenerative disease characterized by the degradation of chondrocyte extracellular matrix (ECM). Previous studies have suggested that microRNAs (miRNAs) are associated with OA, but the role of miR-146b in OA remains unclear. The aim of this study was to determine the role of miR-146b in OA progression. The effect of miR-146b on ECM degradation were studied in mouse chondrocytes transfected with miRNA and treated with IL-1β. Cell viability and the expression levels of proteolytic enzymes in the transfected cells were assessed by real-time RT-PCR, ELISA and Western blots. We found downregulation of miR-146b expression in chondrocytes dramatically inhibited IL-1β-induced caspase activation and proteolytic enzyme expression via influencing its targeted Alpha-2-macroglobulin (A2M). Luciferase reporter assays confirmed that A2M mRNA was negatively regulated by miR-146b in chondrocytes. Intra-articular injection of antago-miR-146b against miR-146b effectively protected mice from the progression of DMM-induced osteoarthritis by inhibiting cartilage proteoglycan degradation. Our study indicates that miR-146b plays a critical role in the progression of injury-induced osteoarthritis by directly targeting A2M expression to elevate the proteolytic enzyme production and stimulate chondrocytes apoptosis, and miR-146b as well as A2M could be therapeutic targets.

Association between miRNA polymorphisms and susceptibility to brain tumors: A meta-analysis

BACKGROUND

Previous studies have demonstrated that single-nucleotide polymorphisms (SNPs) in miRNAs are related to the susceptibility to brain tumors, but the conclusions remain controversial. This study was to perform a meta-analysis to re-assess the associations between miRNA SNPs and brain tumor risk.

METHODS

Relevant studies were identified in the databases of PubMed and the Cochrane Library databases. Pooled odds ratio (OR) and 95% confidence interval (95% CI) were calculated to assess the relationships between SNPs and the risk of brain tumors under various genetic models by the STATA software.

RESULTS

Five studies, containing 2275 cases, and 2323 controls, were included, 4 of which evaluated miR-196a2 (rs11614913), 3 for miR-146a (rs2910164) and 2 for miR-499 (rs3746444) and miR-149 (rs2292832), respectively. The meta-analysis indicated that the GG genotype carriers of miR-146a were more susceptible to brain tumors compared with GC genotype carriers (OR = 1.19, 95%CI = 1.01-1.41, P = .036). No significant associations were observed between the SNPs of other miRNAs and the risk of brain tumors. Furthermore, all miRNA polymorphisms did not show significant associations with the risk of glioma subgroup in any genetic models, while meta-analysis of non-glioma subgroup could not be performed due to low statistical power and analysis of only 1 study.

CONCLUSION

Our study suggests that miR-146a polymorphism may modify the risk for brain tumors, but which type (glioma or benign non-glioma tumors) should be verified with large sample size.

Extracellular vesicles from T cells overexpress miR-146b-5p in HIV-1 infection and repress endothelial activation

Human immunodeficiency virus type 1 (HIV-1) infection promotes a generalized activation of host responses that involves not only CD4 T cells, but also cells of the microenvironment, which are not directly infected, such as endothelial cells. The mechanisms triggering HIV-1-associated vascular alterations remain poorly understood. Extracellular vesicles (EVs), implicated in cell-to-cell communication, have been recently described as carriers of microRNAs (miRNAs). Here, we show that miR-146b-5p is upregulated in both CD4 T cells, CD4 T cell-derived EVs and circulating EVs obtained from antiretroviral therapy-naive HIV-1-infected patients. We further demonstrate that EVs from T cell line overexpressing miR-146b-5p mimics (miR-146b-EVs): 1) protect their miRNA cargo from RNase degradation, 2) transfer miR-146b-5p mimics into endothelial cells and 3) reduce endothelial inflammatory responses in vitro and in vivo in the lungs of mice through the downregulation of nuclear factor-κB-responsive molecules. These data advance our understanding on chronic inflammatory responses affecting endothelial homeostasis, in infectious and non-infectious diseases and pave the way for potential new anti-inflammatory strategies.

The RNA-binding protein SRSF1 is a key cell cycle regulator via stabilizing NEAT1 in glioma

The relevance of RNA processing has been increasingly recognized in a variety of diseases. We previously identified serine/arginine-rich splicing factor 1 (SRSF1) as an oncodriver in glioma via splicing control. However, its splicing-independent roles and mechanisms are poorly defined in glioma. In this study, by integrating the data mining of SRSF1-co-expressed genes, SRSF1-affected genes and experimental studies, we demonstrated that SRSF1 was the most highly expressed SRSF in the 9 tumor types tested, and it was a crucial cell cycle regulator in glioma. Importantly, we identified nuclear paraspeckle assembly transcript1 (NEAT1), an upregulated long non-coding RNA (lncRNA) in glioma, as a target of SRSF1. Endogenous NEAT1 inhibition resembled the effect of SRSF1 knockdown on glioma cell proliferation by retarding cell cycle. Mechanistically, we proved that SRSF1 bound to NEAT1 and facilitated its RNA stability. The positive correlation between SRSF1 and NEAT1 levels in cancers further supported the positive regulation of NEAT1 by SRSF1. Collectively, our results provide novel insights on the splicing-independent mechanisms of SRSF1 in glioma, and confirm that NEAT1, whose stability maintained by SRSF1, implicates gliomagenesis by regulating cell cycle. Both SRSF1 and NEAT1 may serve as promising targets for antineoplastic therapies.

LncRNA SOX2-OT regulates proliferation and metastasis of nasopharyngeal carcinoma cells through miR-146b-5p/HNRNPA2B1 pathway

Nasopharyngeal carcinoma (NPC) is an aggressive malignancy with a high mortality on account of its frequent metastasis and poor prognosis. An extensive body of investigations has proven that long noncoding RNAs are implicated in a variety of biological processes. Although SOX2-OT has been reported to play an oncogenic role in osteosarcoma, the mechanism of SOX2-OT-driven NPC progression is still obscure. The aim of this study was to elucidate the biological function of SOX2-OT and the related possible mechanism in NPC. In our study, SOX2-OT was notably elevated in NPC samples and cells. Further, a high expression level of SOX2-OT was correlated with poor clinical outcomes of NPC. Results from loss-of-function experiments suggested that knockdown of SOX2-OT repressed cell proliferation, arrested cell cycle, facilitated cell apoptosis, and inhibited cell metastasis of NPC. To further investigate the molecular mechanism of SOX2-OT, miR-146b-5p was found to directly bind to SOX2-OT, which mediated the role of SOX2-OT in NPC tumorigenesis. In addition, HNRNPA2B1 was a target of miR-146b-5p and SOX2-OT modulated the expression of HNRNPA2B1 through competitively binding to miR-146b-5p. At last, we discovered that SOX2-OT regulated NPC progression by targeting miR-146b-5p/HNRNPA2B1 pathway, which may provide more innovative targets for the treatment of patients with NPC.

MicroRNA-146b Overexpression Promotes Human Bladder Cancer Invasion via Enhancing ETS2-Mediated mmp2 mRNA Transcription

Although microRNAs have been validated to play prominent roles in the occurrence and development of human bladder cancer (BC), alterations and function of many microRNAs (miRNAs) in bladder cancer invasion are not fully explored yet. miR-146b was reported to be a tumor suppressor or oncomiRNA in various types of cancer. However, its accurate expression, function, and mechanism in bladder cancer remain unclear. Here we discovered that miR-146b was frequently upregulated in bladder cancer tissues compared with adjacent non-cancerous tissues. Inhibition of miR-146b resulted in a significant inhibitory effect on the invasion of bladder cancer cells by reducing mmp2 mRNA transcription and protein expression. We further demonstrated that knockdown of miR-146b attenuated ETS2 expression, which was the transcription factor of matrix metalloproteinase (MMP)2. Moreover, mechanistic studies revealed that miR-146b inhibition stabilized ARE/poly(U)-binding/degradation factor 1 (auf1) mRNA by directly binding to its mRNA 3′ UTR, further reduced ets2 mRNA stability, and finally inhibited mmp2 transcription and attenuated bladder cancer invasion abilities. The identification of the miR-146b/AUF1/ETS2/MMP2 mechanism for promoting bladder cancer invasion provides significant insights into understanding the nature of bladder cancer metastasis. Targeting the pathway described here may be a novel approach for inhibiting invasion and metastasis of bladder cancer.

Tumor necrosis factor receptor-associated factor 6 contributes to malignant behavior of human cancers through promoting AKT ubiquitination and phosphorylation

Tumor necrosis factor receptor-associated factor 6 (TRAF6) has been found to be involved in carcinogenesis in multiple cancers. However, the precise role of TRAF6 in cancer has not been extensively investigated and remains largely unknown. In this study, we aimed to investigate the biological function of TRAF6 and its underlying molecular mechanisms in cancer. A positive correlation between poor tumor differentiation and TRAF6 expression status was observed in both oral cancer and breast cancer. Overexpression of TRAF6 promoted proliferation, migration, and G₀ /G₁ to S phase transition in tumor cells. Tumor necrosis factor receptor-associated factor 6-mediated AKT ubiquitination and subsequent phosphorylation played an essential role in the control of tumor cell malignant behavior. In vivo treatment with TRAF6, but not the E3 ligase deficient TRAF6 mutant, facilitated tumor growth. Our findings indicate that TRAF6 contributes to malignant behavior of human cancers through promoting AKT ubiquitination and phosphorylation. Therefore, TRAF6 could serve as a therapeutic target in cancers.

Inhibition of miR146b-5p suppresses CT-guided renal cell carcinoma by targeting TRAF6

Renal cell carcinoma (RCC) is one of the most common malignancies in the urinary system. Due to the lack of early symptoms, diagnosis of RCC usually occurs at late stages or after cancer metastasis leading to poor prognosis. Therefore, it is crucial to study early molecular mechanisms and biomarkers. Previous studies have suggested that microRNAs are involved in RCC initiation and development, making them a good candidate for early diagnosis and therapy. MiR146b-5P plays important roles in the progression of multiple cancers including thyroid cancer, pancreatic cancer, cervical cancer. However, it is not clear whether and how miR146b-5P is involved in RCC. In this study, we aimed to investigate the function of miR146b-5P in RCC. We examined the expression levels of miR146b-5p in renal cancer tissue and cell lines. We also explored the effects of blocking miR146b-5p in renal tumor growth and inflammatory signaling. Finally, we determined if miR146b-5p regulates tumorigenesis through TRAF6. We found that miR146b-5p levels were significantly increased in renal cancer tissue and renal cancer cells. Blocking miR146b-5p suppressed renal tumor growth and enhanced inflammatory response through increased TRAF6 expression. These effects were eliminated in TRAF6 knockout mice. Our results suggest that enhanced miR146b-5p expression may be a biomarker for RCC and modulating miR146b-5p and TRAF6 levels represent a potential therapeutic strategy for RCC.

Splicing factor SRSF1 promotes gliomagenesis via oncogenic splice-switching of MYO1B

Abnormal alternative splicing (AS) caused by alterations to splicing factors contributes to tumor progression. Serine/arginine splicing factor 1 (SRSF1) has emerged as a key oncodriver in numerous solid tumors, leaving its roles and mechanisms largely obscure in glioma. Here, we demonstrate that SRSF1 is increased in glioma tissues and cell lines. Moreover, its expression was correlated positively with tumor grade and Ki-67 index, but inversely with patient survival. Using RNA-Seq, we comprehensively screened and identified multiple SRSF1-affected AS events. Motif analysis revealed a position-dependent modulation of AS by SRSF1 in glioma. Functionally, we verified that SRSF1 promoted cell proliferation, survival, and invasion by specifically switching the AS of the myosin IB (MYO1B) gene and facilitating the expression of the oncogenic and membrane-localized isoform, MYO1B-fl. Strikingly, MYO1B splicing was dysregulated in parallel with SRSF1 expression in gliomas and predicted the poor prognosis of the patients. Further investigation revealed that SRSF1-guided AS of the MYO1B gene increased the tumorigenic potential of glioma cells through the PDK1/AKT and PAK/LIMK pathways. Taken together, we identify SRSF1 as an important oncodriver that integrates AS control of MYO1B into promotion of gliomagenesis and represents a potential prognostic biomarker and target for glioma therapy.

Role of miR-486-5p in regulating renal cell carcinoma cell proliferation and apoptosis via TGF-β-activated kinase 1

Renal cell carcinoma (RCC) is a common kidney tumor in adults. The role of miR-486-5p in RCC is unknown. The aim of our study was to identify new targets regulated by miR-486-5p in RCC, to obtain a deeper insight into the network and to better understand the role of these microRNAs and their targets in carcinogenesis of RCC. We performed a series of tests and found consistently lower expression levels of miR-486-5p in kidney cancer cells. Restoration of miR-486-5p expression in RCC cells could lead to the suppression of cell proliferation and the increase of cell apoptosis. Further studies demonstrated that TGF-β-activated kinase 1 was a target gene of miR-486-5p in kidney cancer cells. It was also shown that C-C motif chemokine ligand 2 (CCL2) from tumor-associated macrophages downregulated miR-486-5p expression, and miR-486-5p inhibited RCC cell proliferation and apoptosis resistance induced by CCL2. The study demonstrates that there are potential diagnosis and therapy values of miR-486-5p in RCC.

Roles of TRAF6 in Central Nervous System

Tumor necrosis factor receptor-associated factor (TRAF) is an important binding protein of tumor necrosis factor (TNF) superfamily and the toll/IL-1 receptor (TIR) superfamily, which play an important role in innate immunity and ac-quired immunity. TRAFs family have 7 members (TRAF1-7), and TRAF6 has its special facture and biological function. TRAF6 has two special domains: C-terminal domain and N-terminal domain, which could integrate with multiple kinases and regulate signaling pathway function as an E3 ubiquitin ligase. Studies have increasingly found that TRAF6 is closely re-lated to central nervous system diseases, such as stroke, Traumatic brain injury, neurodegenerative diseases and neuropathic pain. Further research on the pathophysiological mechanism may be expected to become the new targets for the treatment of central nervous system diseases

miR-29s function as tumor suppressors in gliomas by targeting TRAF4 and predict patient prognosis

Robust proliferation and apoptosis inhibition of tumor cells are responsible for the high mortality and poor outcome of patients with high-grade gliomas. miR-29a/b/c have been reported to be important suppressors in several human tumor types. However, their exact roles in gliomagenesis and their relevance to patient prognosis remain unclear. In this study, using 187 human glioma specimens and 20 nontumoral brain tissues, we demonstrated that the expression of miR-29a/b/c decreased progressively as the grade of glioma and the Ki-67 index increased. However, the expression of TRAF4, the functional target of miR-29a/b/c, exhibited the inverse trend, and its level was inversely correlated with the levels of miR-29a/b/c. A Kaplan–Meier analysis demonstrated that the miR-29a/b/c and TRAF4 levels were closely associated with patient survival even in patients with the same tumor grade and identical IDH gene status. A functional study verified that miR-29a/b/c induced apoptosis and suppressed the proliferation of glioma cells by directly targeting TRAF4. An investigation of the mechanism revealed that miR-29a/b/c promoted apoptosis through the TRAF4/AKT/MDM2 pathway in a p53-dependent manner, while miR-29a/b/c induced G1 arrest and inhibited tumor cell proliferation by blocking the phosphorylation of AKT and GSK-3β, and the expression of cyclin D1 and c-Myc. Furthermore, TRAF4-knockdown perfectly simulated the anti-glioma effects of miR-29a/b/c. These findings enrich our understanding of gliomagenesis, highlight the prognostic value of miR-29a/b/c and TRAF4, and imply their potential therapeutic roles in malignant gliomas.

Genetic Alterations of TRAF Proteins in Human Cancers

The tumor necrosis factor receptor (TNF-R)-associated factor (TRAF) family of cytoplasmic adaptor proteins regulate the signal transduction pathways of a variety of receptors, including the TNF-R superfamily, Toll-like receptors (TLRs), NOD-like receptors (NLRs), RIG-I-like receptors (RLRs), and cytokine receptors. TRAF-dependent signaling pathways participate in a diverse array of important cellular processes, including the survival, proliferation, differentiation, and activation of different cell types. Many of these TRAF-dependent signaling pathways have been implicated in cancer pathogenesis. Here we analyze the current evidence of genetic alterations of TRAF molecules available from The Cancer Genome Atlas (TCGA) and the Catalog of Somatic Mutations in Cancer (COSMIC) as well as the published literature, including copy number variations and mutation landscape of TRAFs in various human cancers. Such analyses reveal that both gain- and loss-of-function genetic alterations of different TRAF proteins are commonly present in a number of human cancers. These include pancreatic cancer, meningioma, breast cancer, prostate cancer, lung cancer, liver cancer, head and neck cancer, stomach cancer, colon cancer, bladder cancer, uterine cancer, melanoma, sarcoma, and B cell malignancies, among others. Furthermore, we summarize the key in vivo and in vitro evidence that demonstrates the causal roles of genetic alterations of TRAF proteins in tumorigenesis within different cell types and organs. Taken together, the information presented in this review provides a rationale for the development of therapeutic strategies to manipulate TRAF proteins or TRAF-dependent signaling pathways in different human cancers by precision medicine.

Aberrant miRNAs Regulate the Biological Hallmarks of Glioblastoma

GBM is the highest incidence in primary intracranial malignancy, and it remains poor prognosis even though the patient is gave standard treatment. Despite decades of intense research, the complex biology of GBM remains elusive. In view of eight hallmarks of cancer which were proposed in 2011, studies related to the eight biological capabilities in GBM have made great progress. From these studies, it can be inferred that miRs, as a mode of post-transcriptional regulation, are involved in regulating these malignant biological hallmarks of GBM. Herein, we discuss state-of-the-art research on how aberrant miRs modulate the eight hallmarks of GBM. The upregulation of 'oncomiRs' or the genetic loss of tumor suppressor miRs is associated with these eight biological capabilities acquired during GBM formation. Furthermore, we also discuss the applicable clinical potential of these research results. MiRs may aid in the diagnosis and prognosis of GBM. Moreover, miRs are also therapeutic targets of GBM. These studies will develop and improve precision medicine for GBM in the future.

HOXA11-AS promotes the growth and invasion of renal cancer by sponging miR-146b-5p to upregulate MMP16 expression

Recently, increasing studies showed that long noncoding RNAs (lncRNAs) play critical roles in tumor progression. However, the function and underlying mechanism of HOMEOBOX A11 antisense RNA (HOXA11-AS) on renal cancer remain unclear. In the current study, our data showed that the expression of HOXA11-AS was significantly upregulated in clear cell renal cell carcinoma (ccRCC) tissues and cell lines. High HOXA11-AS expression was associated with the advanced clinical stage, tumor stage, and lymph node metastasis. Function assays showed that HOXA11-AS inhibition significantly suppressed renal cancer cells growth, invasion, and ETM phenotype. In addition, underlying mechanism revealed that HOXA11-AS could act as a competing endogenous RNA (ceRNA) that repressed miR-146b-5p expression, which regulated its downstream target MMP16 in renal cancer. Taken together, our findings suggested that HOXA11-AS could promote renal cancer cells growth and invasion by modulating miR-146b-5p-MMP16 axis. Thus, our findings suggested that HOXA11-AS could serve as potential therapeutic target for the treatment of renal cancer.

The immune-related microRNA miR-146b is upregulated in glioblastoma recurrence

Background

Glioblastoma (GBM) has a high rate of local recurrence despite chemoradiotherapy (CRT). Genome-wide expression profiling was performed on patient tumors before and after chemoradiotherapy to identify genes and gene pathways associated with recurrence.

Results

Median time to recurrence was 8.9 months with median time to second surgery of 9.6 months. The microRNA (miRNA) analysis identified 9 oncologic and immune-related miRNAs to be differentially expressed, including the hypoxia-related miR-210 and the immune-modulatory miR-146b. More than 1200 differentially-expressed genes were identified with RNA-sequencing (RNA-seq). Gene set enrichment analysis (GSEA) identified p53 signaling, Notch, Wnt, VEGF, and MEK gene sets enriched in recurrent GBM. Consistent with the miRNA profiling data, the miR-146b target gene set from GSEA analysis was also associated with recurrence.

Methods

Fourteen patients with GBM recurrence after CRT who had available tumor tissue from the initial diagnosis as well as recurrence were selected. Total RNA was isolated from formalin-fixed paraffin-embedded (FFPE) tumor specimens. Genome-wide expression profiling using RT-PCR for miRNA analysis and RNA-seq for messenger RNA (mRNA) analysis were conducted to identify differentially-expressed genes. GSEA was performed on the differential expression data.

Conclusions

Genome-wide expression profiling identifies multiple oncologic and immune-related gene sets associated with GBM recurrence. In particular, immune-related miR-146b is upregulated in recurrence and deserves further investigation.

Novel Insights in the Metabolic Syndrome-induced Oxidative Stress and Inflammation-mediated Atherosclerosis

Context:

Atherosclerosis is a progressive pathological process and a leading cause of mor-tality worldwide. Clinical research and epidemiological studies state that atherosclerosis is caused by an amalgamation of metabolic and inflammatory deregulation involving three important pathological events including Endothelial Dysfunction (ED), Foam Cell Formation (FCF), and Vascular Smooth Muscle Cells (VSMCs) proliferation and migration.

Objectives:

Research in recent years has identified Metabolic Syndrome (MS), which involves factors such as obesity, insulin resistance, dyslipidemia and diabetes, to be responsible for the pathophysiol-ogy of atherosclerosis. These factors elevate oxidative stress and inflammation-induced key signalling molecules and various microRNAs (miRs). In present study, we have reviewed recently identified molecular targets in the pathophysiology of atherosclerosis.

Methods:

Scientific literature obtained from databases such as university library, PubMed and Google along with evidences from published experimental work in relevant journals has been sum-marized in this review article.

Results:

The molecular events and cell signalling implicated in atherogenic processes of ED, FCF and VSMCs hyperplasia are sequential and progressive, and involve cross talks at many levels. Specific molecules such as transcription factors, inflammatory cytokines and chemokines and miRs have been identified playing crucial role in most of the events leading to atherosclerosis.

Conclusion:

Studies associated with MS induced oxidative stress- and inflammation- mediated sig-nalling pathways along with critical miRs help in better understanding of the pathophysiology of ath-erosclerosis. Several key molecules discussed in this review could be potent target for the prevention and treatment of atherosclerosis.

HMGA2 promotes glioma invasion and poor prognosis via a long-range chromatin interaction

To identify the function and underlying mechanisms of HMGA2 on the prognosis and invasion of gliomas, HMGA2 was detected by immunohistochemistry. The Kaplan‐Meier and Cox's regression analysis results showed that higher HMGA2 level predicted the poorer outcomes of glioma patients. ChIP‐qPCR, DNA electrophoretic mobility shift assay, chromosome conformation capture, and co‐immunoprecipitation were applied to identify HMGA2‐activated target sites, which were further verified by mRNA and protein expression detection. Transwell and orthotopic implantation were used to investigate the roles of HMGA2 in glioma cells. HMGA2 shRNA transfection inhibited glioblastoma invasion. Mechanistically, we first discovered that HMGA2, together with GCN5, facilitated the invasion of glioma cells via inducing chromatin conformational remodeling of the MMP2 gene promoter and epigenetically activating MMP2 gene transcription. Our results indicated that HMGA2, as a novel GCN5 recognition partner and histone acetylation modulator, may be novel prognostic indicator and promising glioma treatment target.