AdipoR1-mediated miR-3908 inhibits glioblastoma tumorigenicity through downregulation of STAT2 associated with the AMPK/SIRT1 pathway

The Role of Non-Coding RNAs in Epigenetic Dysregulation in Glioblastoma Development

Glioblastoma (GBM) is a primary brain tumor arising from glial cells. The tumor is highly aggressive, the reason for which it has become the deadliest brain tumor type with the poorest prognosis. Like other cancers, it compromises molecular alteration on genetic and epigenetic levels. Epigenetics refers to changes in gene expression or cellular phenotype without the occurrence of any genetic mutations or DNA sequence alterations in the driver tumor-related genes. These epigenetic changes are reversible, making them convenient targets in cancer therapy. Therefore, we aim to review critical epigenetic dysregulation processes in glioblastoma. We will highlight the significant affected tumor-related pathways and their outcomes, such as regulation of cell cycle progression, cell growth, apoptosis, angiogenesis, cell invasiveness, immune evasion, or acquirement of drug resistance. Examples of molecular changes induced by epigenetic modifications, such as DNA epigenetic alterations, histone post-translational modifications (PTMs), and non-coding RNA (ncRNA) regulation, are highlighted. As understanding the role of epigenetic regulators and underlying molecular mechanisms in the overall pro-tumorigenic landscape of glioblastoma is essential, this literature study will provide valuable insights for establishing the prognostic or diagnostic value of various non-coding transcripts, including miRNAs.

Comprehensive Analysis of CircRNA Expression Profiles in Multiple Tissues of Pigs

Circular RNAs (circRNAs) are a class of non-coding RNAs with diverse functions, and previous studies have reported that circRNAs are involved in the growth and development of pigs. However, studies about porcine circRNAs over the past few years have focused on a limited number of tissues. Based on 215 publicly available RNA sequencing (RNA-seq) samples, we conducted a comprehensive analysis of circRNAs in nine pig tissues, namely, the gallbladder, heart, liver, longissimus dorsi, lung, ovary, pituitary, skeletal muscle, and spleen. Here, we identified a total of 82,528 circRNAs and discovered 3818 novel circRNAs that were not reported in the CircAtlas database. Moreover, we obtained 492 housekeeping circRNAs and 3489 tissue-specific circRNAs. The housekeeping circRNAs were enriched in signaling pathways regulating basic biological tissue activities, such as chromatin remodeling, nuclear-transcribed mRNA catabolic process, and protein methylation. The tissue-specific circRNAs were enriched in signaling pathways related to tissue-specific functions, such as muscle system process in skeletal muscle, cilium organization in pituitary, and cortical cytoskeleton in ovary. Through weighted gene co-expression network analysis, we identified 14 modules comprising 1377 hub circRNAs. Additionally, we explored circRNA-miRNA-mRNA networks to elucidate the interaction relationships between tissue-specific circRNAs and tissue-specific genes. Furthermore, our conservation analysis revealed that 19.29% of circRNAs in pigs shared homologous positions with their counterparts in humans. In summary, this extensive profiling of housekeeping, tissue-specific, and co-expressed circRNAs provides valuable insights into understanding the molecular mechanisms of pig transcriptional expression, ultimately deepening our understanding of genetic and biological processes.

Atractylodes lancea and Magnolia officinalis combination protects against high fructose-impaired insulin signaling in glomerular podocytes through upregulating Sirt1 to inhibit p53-driven miR-221

ETHNOPHARMACOLOGICAL RELEVANCE

In traditional Chinese medicine, a long term of improper diet causes the Dampness and disturbs Zang-Fu's functions including Kidney deficiency. Atractylodes lancea (Atr) and Magnolia officinalis (Mag) as a famous herb pair are commonly used to transform Dampness, with kidney protection.

AIM OF THE STUDY

To explore how Atr and Mag protected against insulin signaling impairment in glomerular podocytes induced by high dietary fructose feeding, a major contributor for insulin resistance in glomerular podocyte dysfunction.

MATERIALS AND METHODS

Liquid chromatography-tandem mass spectrometry (LC-MS/MS) analyze constituents of Atr and Mag. Rat model was induced by 10% fructose drinking water in vivo, and heat-sensitive human podocyte cells (HPCs) were exposed to 5 mM fructose in vitro. Animal or cultured podocyte models were treated with different doses of Atr, Mag or Atr and Mag combination. Western blot, qRT-PCR and immunofluorescence assays as well as other experiments were performed to detect adiponectin receptor protein 1 (AdipoR1), protein kinase B (AKT), Sirt1, p53 and miR-221 levels in rat glomeruli or HPCs, respectively.

RESULTS

Fifty-five components were identified in Atr and Mag combination. Network pharmacology analysis indicated that Atr and Mag combination might affect insulin signaling pathway. This combination significantly improved systemic insulin resistance and prevented glomerulus morphological damage in high fructose-fed rats. Of note, high fructose decreased IRS1, AKT and AdipoR1 in rat glomeruli and cultured podocytes. Further data from cultured podocytes with Sirt1 inhibitor/agonist, p53 agonist/inhibitor, or miR-221 mimic/inhibitor showed that high fructose downregulated Sirt1 to stimulate p53-driven miR-221, resulting in insulin signaling impairment. Atr and Mag combination effectively increased Sirt1, and decreased p53 and miR-221 in in vivo and in vitro models.

CONCLUSIONS

Atr and Mag combination improved insulin signaling in high fructose-stimulated glomerular podocytes possibly through upregulating Sirt1 to inhibit p53-driven miR-221. Thus, the regulation of Sirt1/p53/miR-221 by this combination may be a potential therapeutic approach in podocyte insulin signaling impairment.

Adiponectin, the adiponectin paradox, and Alzheimer's Disease: Is this association biologically plausible?

Dementia, especially Alzheimer's Disease (AD) and vascular dementia, is a major public health problem that continues to expand in both economically emerging and hegemonic countries. In 2017, the World Alzheimer Report estimated that over 50 million people were living with dementia globally. Metabolic dysfunctions of brain structures such as the hippocampus and cerebral cortex have been implicated as risk factors for dementia. Several well-defined metabolic risk factors for AD include visceral obesity, chronic inflammation, peripheral and brain insulin resistance, type 2 diabetes mellitus (T2DM), hypercholesterolemia, and others. In this review, we describe the relationship between the dysmetabolic mechanisms, although still unknown, and dementia, particularly AD. Adiponectin (ADPN), the most abundant circulating adipocytokine, acts as a protagonist in the metabolic dysfunction associated with AD, with unexpected and intriguing dual biological functions. This contradictory role of ADPN has been termed the adiponectin paradox. Some evidence suggests that the adiponectin paradox is important in amyloidogenic evolvability in AD. We present cumulative evidence showing that AD and T2DM share many common features. We also review the mechanistic pathways involving brain insulin resistance. We discuss the importance of the evolvability of amyloidogenic proteins (APs), defined as the capacity of a system for adaptive evolution. Finally, we describe potential therapeutic strategies in AD, based on the adiponectin paradox.

miR-593-3p Promotes Proliferation and Invasion in Prostate Cancer Cells by Targeting ADIPOR1

Background

Accumulating evidence has indicated that dysregulation of microRNAs (miRNAs) contributes to the tumorigenesis of prostate cancer (PCa). Nevertheless, the role of miR-593-3p in the development of PCa remains unclear. The objective of this study was to investigate the role and mechanisms of miR-593-3p in PCa cells.

Methods

RT-PCR was used to detect the expression levels of miR-593-3p. CCK-8, colony formation, spheroid formation and transwell assays were performed to examine the proliferation, migration and invasion of C4-2, DU145 and RWPE-1 cells. And then, transcriptome sequencing, dual-luciferase reporter assay and Western blot were taken to identify the target gene and downstream mechanisms of miR-593-3p.

Results

Here, we found that miR-593-3p promoted PCa cell proliferation, colony formation, spheroid formation, migration and invasion. Further mechanistic studies revealed that miR-593-3p possessed binding sites of ADIPOR1 3ʹ-UTR and played an important role in 5ʹ-AMP-activated protein kinase (AMPK) signaling pathway and epithelial–mesenchymal transition (EMT) process. In addition, the transfection of si-ADIPOR1 also enhanced the PCa cell proliferation and invasion.

Conclusion

Our study provides an empirical investigation of miR-593-3p, which exerts oncogenic function through targeting ADIPOR1 in PCa cells.

Transformation of fibroblast-like synoviocytes in rheumatoid arthritis; from a friend to foe

Swelling and the progressive destruction of articular cartilage are major characteristics of rheumatoid arthritis (RA), a systemic autoimmune disease that directly affects the synovial joints and often causes severe disability in the affected positions. Recent studies have shown that type B synoviocytes, which are also called fibroblast-like synoviocytes (FLSs), as the most commonly and chiefly resident cells, play a crucial role in early-onset and disease progression by producing various mediators. During the pathogenesis of RA, the FLSs' phenotype is altered, and represent invasive behavior similar to that observed in tumor conditions. Modified and stressful microenvironment by FLSs leads to the recruitment of other immune cells and, eventually, pannus formation. The origins of this cancerous phenotype stem fundamentally from the significant metabolic changes in glucose, lipids, and oxygen metabolism pathways. Moreover, the genetic abnormalities and epigenetic alterations have recently been implicated in cancer-like behaviors of RA FLSs. In this review, we will focus on the mechanisms underlying the transformation of FLSs to a cancer-like phenotype during RA. A comprehensive understanding of these mechanisms may lead to devising more effective and targeted treatment strategies.

Toxicity of orally administered food-grade titanium dioxide nanoparticles

This year, France banned the application of titanium dioxide nanoparticles as a food additive (hereafter, E171) based on the insufficient oral toxicity data. Here, we investigated the subchronic toxic responses of E171 (0, 10, 100, and 1,000 mg/kg) and tried to elucidate the possible toxic mechanism using AGS cells, a human stomach epithelial cell line. There were no dose-related changes in the Organisation for Economic Cooperation and Development test guideline-related endpoints. Meanwhile, E171 deeply penetrated cells lining the stomach tissues of rats, and the IgM and granulocyte-macrophage colony-stimulating factor levels were significantly lower in the blood from rats exposed to E171 compared with the control. The colonic antioxidant protein level decreased with increasing Ti accumulation. Additionally, after 24-h exposure, E171 located in the perinuclear region of AGS cells and affected expression of endoplasmic reticulum stress-related proteins. However, cell death was not observed up to the used maximum concentration. A gene profile analysis also showed that immune response-related microRNAs were most strongly affected by E171 exposure. Collectively, we concluded that the NOAEL of E171 for 90 days repeated oral administration is between 100 and 1,000 mg/kg for both male and female rats. Additionally, further study is needed to clarify the possible carcinogenesis following the chronic accumulation in the colon.

Identification of a Set of Genes Improving Survival Prediction in Kidney Renal Clear Cell Carcinoma through Integrative Reanalysis of Transcriptomic Data

Background

With an enormous amount of research concerning kidney cancer being conducted, various treatments have been applied to its cure. However, high recurrence and metastasis rates continue to pose a threat to the survival of patients with kidney renal clear cell carcinoma (KIRC).

Methods

Data from The Cancer Genome Atlas were downloaded, and a series of analyses were performed, including differential analysis, Cox analysis, weighted gene coexpression network analysis, least absolute shrinkage and selection operator analysis, multivariate Cox analysis, survival analysis, and receiver operating characteristic curve and functional enrichment analysis.

Results

A total of 5,777 differentially expressed genes were identified from the differential analysis. The Cox analysis showed 1,853 significant genes (P < 0.01). Weighted gene coexpression network analysis revealed that 226 genes in the module were related to clinical parameters, including Tumor-Node-Metastasis (TNM) staging. Least absolute shrinkage and selection operator and multivariate Cox analyses suggested that four genes (CDKL2, LRFN1, STAT2, and SOWAHB) had a potential function in predicting the survival time of patients with KIRC. Survival analysis uncovered that a high risk of these four genes was associated with an unfavorable prognosis. Receiver operating characteristic curve analysis further confirmed the accuracy of the risk score model. The analysis of clinicopathological parameters of the four identified genes revealed that they were associated with the progression of KIRC.

Conclusion

The gene expression model consisting of CDKL2, LRFN1, STAT2, and SOWAHB is a promising tool for predicting the prognosis of patients with KIRC. The results of this study may provide insights into the diagnosis and treatment of KIRC.

miRNA signature in glioblastoma: Potential biomarkers and therapeutic targets

MicroRNAs (miRNAs) are transcripts with sizes of about 22 nucleotides, which are produced through a multistep process in the nucleus and cytoplasm. These transcripts modulate the expression of their target genes through binding with certain target regions, particularly 3' suntranslated regions. They are involved in the pathogenesis of several kinds of cancers, such as glioblastoma. Several miRNAs, including miR-10b, miR-21, miR-17-92-cluster, and miR-93, have been up-regulated in glioblastoma cell lines and clinical samples. On the other hand, expression of miR-7, miR-29b, miR-32, miR-34, miR-181 family members, and a number of other miRNAs have been decreased in this type of cancer. In the current review, we explain the role of miRNAs in the pathogenesis of glioblastoma through providing a summary of studies that reported dysregulation of these epigenetic effectors in this kind of brain cancer.

LncRNA DLX6-AS1 Promotes the Progression of Neuroblastoma by Activating STAT2 via Targeting miR-506-3p

Background

Neuroblastoma (NB) is a common malignant tumor of the sympathetic nervous system, mainly disturbing children. Long non-coding RNAs (lncRNAs) serving as promising cancer biomarkers have been well recognized. Our study intends to explore the functions of lncRNA X–inactive specific transcript (DLX6-AS1) in NB and provide a potential action mechanism.

Methods

The expression of DLX6-AS1, miR-506-3p and signal transducer and activator of transcription 2 (STAT2) was measured by quantitative real-time polymerase chain reaction (qRT-PCR). Cell proliferation was assessed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and colony formation assay. Cell cycle distribution was determined by flow cytometry assay. The protein level of cell cycle-related markers and STAT2 was detected by Western blot. Glycolysis progress was evaluated according to glucose consumption, lactate production and ATP level. The target genes were predicted by the online database Starbase3.0 and verified by dual-luciferase reporter assay.

Results

DLX6-AS1 expression was highly elevated in NB tissues and cells. DLX6-AS1 deficiency inhibited NB cell proliferation, cell cycle and glycolysis in vitro. MiR-506-3p was a target of DLX6-AS1, and miR-506-3p absence partly reversed the effects of DLX6-AS1 deficiency. Besides, STAT2 was targeted by miR-506-3p, and its expression was regulated by DLX6-AS1 through miR-506-3p. MiR-506-3p restoration also inhibited NB cell malignant behaviors, and STAT2 overexpression partially abolished the role of miR-506-3p restoration. Moreover, DLX6-AS1 deficiency weakened tumor growth in vivo.

Conclusion

DLX6-AS1 regulated cell proliferation, cell cycle and glycolysis in vitro and tumor growth in vivo to promote the development of NB by upregulating STAT2 via targeting miR-506-3p.

Epstein-Barr virus-derived circular RNA LMP2A induces stemness in EBV-associated gastric cancer

Cancer stem cells (CSCs) are cancer-initiating cells that are not only a source of tumorigenesis but also the cause of tumour progression, metastasis and therapy resistance. EBV-associated gastric cancer (EBVaGC) is a distinct subtype of gastric cancer with unique clinicopathological and molecular features. However, whether CSCs exist in EBVaGC, and the tumorigenic mechanism of EBV, remains unclear. Here, NOD/SCID mice were injected subcutaneously with the EBVaGC cell line SNU719 and treated with 5-fluorouracil weekly. Successive generations of xenografts yielded a highly malignant EBVaGC cell line, SNU-4th, which displays properties of CSCs and mainly consists of CD44⁺ CD24^- cells. In SNU-4th cells, an EBV-encoded circRNA, ebv-circLMP2A, expression increased and plays crucial roles in inducing and maintaining stemness phenotypes through targeting miR-3908/TRIM59/p53 axis. Additionally, high expression of ebv-circLMP2A is significantly associated with metastasis and poor prognosis in patients with EBVaGC. These findings not only provide evidence for the existence of CSCs in EBVaGC and elucidate the pathogenic mechanism of ebv-circLMP2A in EBVaGC, but also provide a promising therapeutic target for EBVaGC.

[High expression of STAT2 in ovarian cancer and its effect on metastasis of ovarian cancer cells]

OBJECTIVE

To investigate the expression of signal transduction and activator of transcription 2 (STAT2) in ovarian cancer and its correlation with the prognosis of ovarian cancer patients and explore the role of STAT2 inregulating metastasis of ovarian cancer cells.

METHODS

RT-qPCR was performed to detect the expression of STAT2 mRNA in 62 fresh frozen ovarian cancer tissues and 62 normal ovarian tissues; immunohistochemistry was used to detect STAT2 protein expressions in 95 paraffin-embedded ovarian cancer samples and 33 normal ovarian tissues. Kaplan-Meier method was used to analyze the correlation between the expression of STAT2 and the prognosis of the patients. We also examined the relationship between STAT2 and the patients' prognosis by analyzing the data in Kaplan-Meier Plotter database. Western blotting was performed to detect the expression of STAT2 in different ovarian cancer cell lines. In A2780 cells with the highest STAT2 expression, we examined the effects of STAT2 interference on cell migration and invasiveness using Transwell migration assay and on the expressions of the downstream molecule epidermal growth factor receptor (EGFR).

RESULTS

Ovarian cancer tissues expressed significantly higher levels of STAT2 mRNA than normal ovarian tissue. A high STAT2 mRNA expression was correlated with an advanced FIGO stage. Immunohistochemistry showed that 67.4% of the ovarian cancer samples, as compared with 28.3% of normal ovarian tissues, showed high STAT2 expressions. In ovarian cancer patients, a high expression of STAT2 protein was associated with ascites volume, distant metastasis and FIGO stage (P < 0.05). Survival analysis showed that ovarian cancer patients with a high expression of STAT2 protein had poor overall survival (P=0.021) and progression-free survival (P=0.018). STAT2 was overexpressed in all the ovarian cancer cell lines tested, and A2780 cell lines showed the highest expression. Interference of STAT2 significantly suppressed the migration and invasiveness (P < 0.01) and lowered the expression level of EGFR in A2780 cells.

CONCLUSIONS

STAT2 is overexpressed in ovarian cancer. A high expression of STAT2 is associated with a poor prognosis of ovarian cancer patients. STAT2 may promote the metastasis of ovarian cancer by enhancing the expression of EGFR.

Noninvasive quantification of SIRT1 expression-activity and pharmacologic inhibition in a rat model of intracerebral glioma using 2-[18F]BzAHA PET/CT/MRI

Background

Several studies demonstrated that glioblastoma multiforme progression and recurrence is linked to epigenetic regulatory mechanisms. Sirtuin 1 (SIRT1) plays an important role in glioma progression, invasion, and treatment response and is a potential therapeutic target. The aim of this study is to test the feasibility of 2-[¹⁸F]BzAHA for quantitative imaging of SIRT1 expression–activity and monitoring pharmacologic inhibition in a rat model of intracerebral glioma.

Methods

Sprague Dawley rats bearing 9L (N = 12) intracerebral gliomas were injected with 2-[¹⁸F]BzAHA (300–500 µCi/animal i.v.) and dynamic positron-emission tomography (PET) imaging was performed for 60 min. Then, SIRT1 expression in 9L tumors (N = 6) was studied by immunofluorescence microscopy (IF). Two days later, rats with 9L gliomas were treated either with SIRT1 specific inhibitor EX-527 (5 mg/kg, i.p.; N = 3) or with histone deacetylases class IIa specific inhibitor MC1568 (30 mg/kg, i.p.; N = 3) and 30 min later were injected i.v. with 2-[¹⁸F]BzAHA. PET-computerized tomography-magnetic resonance (PET/CT/MR) images acquired after EX-527 and MC1568 treatments were co-registered with baseline images.

Results

Standard uptake values (SUVs) of 2-[¹⁸F]BzAHA in 9L tumors measured at 20 min post-radiotracer administration were 1.11 ± 0.058 and had a tumor-to-brainstem SUV ratio of 2.73 ± 0.141. IF of 9L gliomas revealed heterogeneous upregulation of SIRT1, especially in hypoxic and peri-necrotic regions. Significant reduction in 2-[¹⁸F]BzAHA SUV and distribution volume in 9L tumors was observed after administration of EX-527, but not MC1568.

Conclusions

PET/CT/MRI with 2-[¹⁸F]BzAHA can facilitate studies to elucidate the roles of SIRT1 in gliomagenesis and progression, as well as to optimize therapeutic doses of novel SIRT1 inhibitors.

The cross-talk between adipokines and miRNAs in health and obesity-mediated diseases

BACKGROUND

Multiple studies have revealed a direct correlation between obesity and the development of multiple comorbidities, including metabolic diseases, cardiovascular disorders, chronic inflammatory disease, and cancers. However, the molecular mechanism underlying the link between obesity and the progression of these diseases is not completely understood. Adipokines are factors that are secreted by adipocytes and play a key role in whole body homeostasis. Collaboratively, miRNAs are suggested to have key functions in the development of obesity and obesity-related disorders. Based on recently emerging evidence, obesity leads to the dysregulation of both adipokines and obesity-related miRNAs. In the present study, we described the correlations between obesity and its related diseases that are mediated by the mutual regulatory effects of adipokines and miRNAs.

METHODS

We reviewed current knowledge of the modulatory effects of adipokines on miRNAs activity and their relevant functions in pathological conditions and vice versa.

RESULTS

Our research reveals the ability of adipokines and miRNAs to control the expression and activity of the other class of molecules, and their effects on obesity-related diseases.

CONCLUSIONS

This study may help researchers develop a roadmap for future investigations and provide opportunities to develop new therapeutic and diagnostic methods for treating obesity-related diseases.

Comprehensive epigenetic landscape of rheumatoid arthritis fibroblast-like synoviocytes

Epigenetics contributes to the pathogenesis of immune-mediated diseases like rheumatoid arthritis (RA). Here we show the first comprehensive epigenomic characterization of RA fibroblast-like synoviocytes (FLS), including histone modifications (H3K27ac, H3K4me1, H3K4me3, H3K36me3, H3K27me3, and H3K9me3), open chromatin, RNA expression and whole-genome DNA methylation. To address complex multidimensional relationship and reveal epigenetic regulation of RA, we perform integrative analyses using a novel unbiased method to identify genomic regions with similar profiles. Epigenomically similar regions exist in RA cells and are associated with active enhancers and promoters and specific transcription factor binding motifs. Differentially marked genes are enriched for immunological and unexpected pathways, with “Huntington’s Disease Signaling” identified as particularly prominent. We validate the relevance of this pathway to RA by showing that Huntingtin-interacting protein-1 regulates FLS invasion into matrix. This work establishes a high-resolution epigenomic landscape of RA and demonstrates the potential for integrative analyses to identify unanticipated therapeutic targets.

Fibroblast-like synoviocytes (FLS) in the intimal layer of the synovium can become invasive and destroy cartilage in patients with rheumatoid arthritis (RA). Here the authors integrate a variety of epigenomic data to map the epigenome of FLS in RA and identify potential therapeutic targets.