NF-κB-induced IL-6 ensures STAT3 activation and tumor aggressiveness in glioblastoma

A systematic approach to decipher crosstalk in the p53 signaling pathway using single cell dynamics

The transcription factors NF-κB and p53 are key regulators in the genotoxic stress response and are critical for tumor development. Although there is ample evidence for interactions between both networks, a comprehensive understanding of the crosstalk is lacking. Here, we developed a systematic approach to identify potential interactions between the pathways. We perturbed NF-κB signaling by inhibiting IKK2, a critical regulator of NF-κB activity, and monitored the altered response of p53 to genotoxic stress using single cell time lapse microscopy. Fitting subpopulation-specific computational p53 models to this time-resolved single cell data allowed to reproduce in a quantitative manner signaling dynamics and cellular heterogeneity for the unperturbed and perturbed conditions. The approach enabled us to untangle the integrated effects of IKK/ NF-κB perturbation on p53 dynamics and thereby derive potential interactions between both networks. Intriguingly, we find that a simultaneous perturbation of multiple processes is necessary to explain the observed changes in the p53 response. Specifically, we show interference with the activation and degradation of p53 as well as the degradation of Mdm2. Our results highlight the importance of the crosstalk and its potential implications in p53-dependent cellular functions.

Cells can respond to external and internal inputs by transducing information to the nucleus where transcription factors initiate corresponding cellular responses. Cellular signaling is mediated by several pathways; molecular networks that can interact with each other, which alters signal processing and modulates cellular responses. As deregulated signaling can lead to the development of tumors it is important to understand not only how signaling pathways function but also the contribution of their interaction on the signaling dynamics. Here, we analyzed the interplay of the IKK/ NF-κB and p53 pathway, which are both critical for the cellular response to DNA damage and have been implicated in tumor development. To systematically identify interaction points between both pathways, we perturbed IKK/ NF-κB signaling and tracked the changes in the response of p53 to DNA damage. Using computational methods, we show that several reactions in the p53 pathway are simultaneously affected by NF-κB signaling and that this combined action is necessary to explain altered behaviour of the p53 pathway. Hence, our results provide new insights into the interplay between the NF-κB and p53 pathway and help to gain a more comprehensive understanding of the crosstalk.

Ascites-derived ALDH+CD44+ tumour cell subsets endow stemness, metastasis and metabolic switch via PDK4-mediated STAT3/AKT/NF-κB/IL-8 signalling in ovarian cancer

Background

Ovarian cancer is characterised by frequent recurrence due to persistent presence of residual cancer stem cells (CSCs). Here, we identify and characterise tumour subsets from ascites-derived tumour cells with stemness, metastasis and metabolic switch properties and to delineate the involvement of pyruvate dehydrogenase kinase 4 (PDK4) in such process.

Methods

Ovarian cancer cells/cell lines derived from ascites were used for tumourspheres/ALDH+CD44+ subset isolation. The functional roles and downstream signalling of PDK4 were explored. Its association with clinical outcome of ovarian cancer was analysed.

Results

We demonstrated enhanced CSC characteristics of tumour cells derived from ovarian cancer ascites, concomitant with ALDH and CD44 subset enrichment and high PDK4 expression, compared to primary tumours. We further showed tumourspheres/ALDH+CD44+ subsets from ascites-derived tumour cells/cell lines with CSC properties and enhanced glycolysis. Clinically, PDK4 expression was correlated with aggressive features. Notably, blockade of PDK4 in tumourspheres/ALDH+CD44+ subsets led to inhibition of CSC characteristics, glycolysis and activation of STAT3/AKT/NF-κB/IL-8 (signal transducer and activator of transcription 3/protein kinases B/nuclear factor-κB/interleukin-8) signalling. Conversely, overexpression of PDK4 in ALDH−CD44– subsets exerted the opposite effects.

Conclusion

Ascites-derived ALDH+CD44+ tumour cell subsets endow stemness, metastatic and metabolic switch properties via PDK4-mediated STAT3/AKT/NF-κB/IL-8 signalling, suggesting PDK4 as a viable therapeutic molecular target for ovarian cancer management.

Dexamethasone suppresses the Th17/1 cell polarization in the CD4+ T cells from patients with primary immune thrombocytopenia

INTRODUCTION

Primary immune thrombocytopenia (ITP) is an acquired autoimmune disease with increased Th17 cells in peripheral blood. Th17/1 cells, which were recently characterized as a new differentiated Th17 lineage secreting IL-17 and IFN-γ, play an important role in the pathogenesis of multiple autoimmune diseases. In this study, we investigated whether Th17/1 cells are involved in the pathogenesis of ITP.

MATERIALS AND METHODS

Peripheral blood was obtained from 44 ITP patients and 50 healthy controls. The percentages of T cell subsets were evaluated. We also detected molecular signature of Th17/1 cells in CD4⁺ T cells. Besides, CD4⁺ T cells from ITP patients were treated with dexamethasone, the inhibitor of NF-κB, or rapamycin to evaluate the impact and mechanism of dexamethasone treatment on Th17/1 cells.

RESULTS

We found an elevated percentage and an enhanced specific molecular signature of Th17/1 cells in CD4⁺ T cells in ITP patients. The percentage of Th17/1 cells was correlated positively with Th17 cells in ITP patients and healthy controls. The percentage of Th17/1 cells was correlated with corticosteroid resistance. Dexamethasone reversed the molecular signature of Th17/1 cells and decreased the percentage of Th17/1 cells in vitro. Treatment of dexamethasone and the inhibitor of NF-κB suppressed the phosphorylation of STAT3, while dexamethasone treatment also inhibited the phosphorylation of NF-κB p65.

CONCLUSIONS

Our data suggested Th17/1 cells may contribute to the pathogenesis of ITP and dexamethasone could inhibit Th17/1 cells through NF-κB/STAT3 pathway. These results may provide a potential therapeutic strategy of correcting the Th17/1 cell deviation in ITP.

The long non-coding RNA DANCR regulates the inflammatory phenotype of breast cancer cells and promotes breast cancer progression via EZH2-dependent suppression of SOCS3 transcription

Long non-coding RNA (lncRNA) is involved in the regulation of tumorigenesis and metastasis. In this study, we focused on the clinical relevance, biological effects, and molecular mechanisms of the lncRNA differentiation antagonizing non-protein coding RNA (DANCR) in breast cancer. We compared the expression of DANCR between breast cancer and normal tissues, and between breast cancer cell lines and normal breast epithelial cells using quantitative real-time PCR (qRT-PCR) analysis. By knocking down and overexpressing DANCR, we assessed its significance in regulating viability (MTT assay), migration/invasion (Transwell assay), epithelial-mesenchymal transition (western blot), stemness (mammosphere formation assay and western blot), and production of inflammatory cytokines (qRT-PCR and ELISA) of breast cancer cells in vitro, as well as xenograft growth in vivo. Furthermore, using ChIP and RNA immunoprecipitation, we examined the reciprocal regulation between DANCR and suppressor of cytokine signaling 3 (SOCS3) in breast cancer. DANCR was significantly up-regulated in tissue samples from patients with breast cancer, as well as in breast cancer cell lines, as compared with normal tissues and breast epithelial cells, respectively. The highest DANCR expression levels were associated with advanced tumor grades or lymph node metastasis. DANCR was necessary and sufficient to control multiple malignant phenotypes of breast cancer cells in vitro and xenograft growth in vivo. Mechanistically, DANCR promoted the binding of enhancer of zeste homolog 2 (EZH2) to the promoter of SOCS3, thereby epigenetically inhibiting SOCS3 expression. Functionally, SOCS3 up-regulation or EZH2 inhibition could rescue multiple malignant phenotypes induced by DANCR. Our data indicate that DANCR is a pleiotropic oncogenic lncRNA in breast cancer. Boosting SOCS3 expression may reverse the oncogenic activities of DANCR and thus provide a therapeutic strategy for breast cancer treatment.

Type I collagen promotes the migration and myogenic differentiation of C2C12 myoblastsviathe release of interleukin-6 mediated by FAK/NF-κB p65 activation

Type I collagen has the potential to promote the migration and differentiation of C₂C₁₂myoblastviaIL-6 release that was mediated by FAK/NF-κB pathway.

Hic-5 deficiency protects cerulein-induced chronic pancreatitis via down-regulation of the NF-κB (p65)/IL-6 signalling pathway

Chronic pancreatitis (CP), characterized by pancreatic fibrosis, is a recurrent, progressive and irreversible disease. Activation of the pancreatic stellate cells (PSCs) is considered a core event in pancreatic fibrosis. In this study, we investigated the role of hydrogen peroxide-inducible clone-5 (Hic-5) in CP. Analysis of the human pancreatic tissue samples revealed that Hic-5 was overexpressed in patients with CP and was extremely low in healthy pancreas. Hic-5 was significant up-regulated in the activated primary PSCs independently from transforming growth factor beta stimulation. CP induced by cerulein injection was ameliorated in Hic-5 knockout (KO) mice, as shown by staining of tissue level. Simultaneously, the activation ability of the primary PSCs from Hic-5 KO mice was significantly attenuated. We also found that the Hic-5 up-regulation by cerulein activated the NF-κB (p65)/IL-6 signalling pathway and regulated the downstream extracellular matrix (ECM) genes such as α-SMA and Col1a1. Therefore, we determined whether suppressing NF-κB/p65 alleviated CP by treating mice with the NF-κB/p65 inhibitor triptolide in the cerulein-induced CP model and found that pancreatic fibrosis was alleviated by NF-κB/p65 inhibition. These findings provide evidence for Hic-5 as a therapeutic target that plays a crucial role in regulating PSCs activation and pancreatic fibrosis.

Increased Six1 expression in macrophages promotes hepatocellular carcinoma growth and invasion by regulating MMP-9

Increased Six1 expression is commonly observed in a variety of cancers and is positively correlated with cancer progression and metastasis. Nevertheless, the mechanism by which Six1 affects the development of hepatocellular carcinoma (HCC) is still unclear. A series of experiments involving cell counting kit-8, colony formation and Transwell assay was used to determine cell proliferation, migration and invasion respectively. Histological examination and immunofluorescence assay were also performed. The messenger RNA and protein expression of interesting genes were determined by real-time reverse transcription-polymerase chain reaction and western blotting respectively. We found that Six1 was up-regulated in HCC and was associated with worse histological grade and poor survival rate. Increased expression of Six1 was shown to be able to boost cell growth, invasion, migration and epithelial-mesenchymal transition (EMT), whereas silencing of Six1 suppressed these malignant phenotypes. Mechanistic investigations revealed that, in macrophages, matrix metalloproteinase 9 (MMP-9) was up-regulated by Six1. Interestingly, Six1 expression in macrophages was also able to trigger MMP-9 induction in HCC cells. Moreover, macrophage Six1 expression was able to induce interleukin-6 (IL-6) up-regulation and increase the activity of signal transducer and activator of transcription 3 (STAT3) in HCC cells, which accounted for the elevated levels of MMP-9 and the higher invasive levels seen in HCC. Increased expression of Six1 in HCC aggravates the malignant behaviour of cancer cells, and we provide novel evidence that macrophage Six1 can stimulate cancer cell invasion by elevating MMP-9 expression.

The Gut-Brain Axis, Paving the Way to Brain Cancer

The gut-brain axis formed by blood and lymphatic vessels paves the way for microbiota to impact the brain. Bacterial populations in the gut are a good candidate for a nongenetic factor contributing substantively to brain tumor development and to the success of therapy. Specifically, suppression of the immune system and induction of inflammation by microbiota sustain proliferative signaling, limit cell death, and induce angiogenesis as well as invasiveness. In addition, altered microbial metabolites and their levels could stimulate cell proliferation. We propose here a novel gear model connecting these complex interdisciplinary fields. Our model may impact mechanistic studies of brain cancer and better treatment outcomes through precision oncology.

Sustained NF-κB-STAT3 signaling promotes resistance to Smac mimetics in Glioma stem-like cells but creates a vulnerability to EZH2 inhibition

Glioblastoma is an incurable and highly aggressive brain tumor. Understanding therapeutic resistance and survival mechanisms driving this tumor type is key to finding effective therapies. Smac mimetics (SM) emerged as attractive cancer therapeutics particularly for tumor populations that are highly resistant to conventional apoptosis-inducing therapies. We evaluated the therapeutic efficacy of SM on Glioma stem-like cells (GSCs) and showed that this family of compounds stimulates an adaptive response triggered by TNFα. Increased expression of TNFα results in a prolonged and sustained activation of NF-κB and STAT3 signaling thus activating several tumor cell resistance mechanisms in GSCs. We show that STAT3 activation is contingent on EZH2 activation and uncover a synergistic lethality between SM and EZH2 inhibitors. Therapeutic inhibition of EZH2 impaired the viability of SM-treated GSCs. Our study outlines the molecular underpinnings of SM resistance in glioblastoma and provides mechanistic insight to overcome this resistance and increase therapeutic efficacy.

Distribution and prognostic impact of microglia/macrophage subpopulations in gliomas

While the central nervous system is considered an immunoprivileged site and brain tumors display immunosuppressive features, both innate and adaptive immune responses affect glioblastoma (GBM) growth and treatment resistance. However, the impact of the major immune cell population in gliomas, represented by glioma‐associated microglia/macrophages (GAMs), on patients’ clinical course is still unclear. Thus, we aimed at assessing the immunohistochemical expression of selected microglia and macrophage markers in 344 gliomas (including gliomas from WHO grade I–IV). Furthermore, we analyzed a cohort of 241 IDH1R132H‐non‐mutant GBM patients for association of GAM subtypes and patient overall survival. Phenotypical properties of GAMs, isolated from high‐grade astrocytomas by CD11b‐based magnetic cell sorting, were analyzed by immunocytochemistry, mRNA microarray, qRT‐PCR and bioinformatic analyses. A higher amount of CD68‐, CD163‐ and CD206‐positive GAMs in the vital tumor core was associated with beneficial patient survival. The mRNA expression profile of GAMs displayed an upregulation of factors that are considered as pro‐inflammatory M1 (eg, CCL2, CCL3L3, CCL4, PTGS2) and anti‐inflammatory M2 polarization markers (eg, MRC1, LGMN, CD163, IL10, MSR1), the latter rather being associated with phagocytic functions in the GBM microenvironment. In summary, we present evidence that human GBMs contain mixed M1/M2‐like polarized GAMs and that the levels of different GAM subpopulations in the tumor core are positively associated with overall survival of patients with IDH1R132H‐non‐mutant GBMs.

Retracted Article: Exosomal miR-25-3p derived from hypoxia tumor mediates IL-6 secretion and stimulates cell viability and migration in breast cancer

Hypoxia is a major hallmark of solid tumors and is associated with malignant phenotypes. Exosomal miRNAs derived from hypoxia tumor cells are implicated in the modulation of cancer progression, whereas, the mechanisms underlying the association between hypoxia and exosomal miR-25-3p during breast cancer progression remain to be further clarified. The present study aimed to investigate the role of exosomal miR-25-3p in regulating breast cancer progression. Herein, we found that miR-25-3p expression was increased in hypoxia tumor-derived exosomes a HIF-1α-dependent manner. Hypoxia exosomes markedly stimulated the viability and migration of normoxia breast cancer cells, which was reversed by miR-25-3p depletion. Inhibition of exosomes miR-25-3p lowered hypoxic-induced the expression of IL-6 and NF-κB from THP-1 and RAW264.7 cells in a TLR7/8-dependent way. Treatment of macrophage supernatant (MS) initially incubated with hypoxic-responsed exosomes accelerated the viability and migration of breast cancer cells, and miR-25-3p depletion relieved the stimulatory effects of hypoxic on cell viability and migration. Moreover, miR-25-3p knockdown dramatically suppressed HIF-1α-induced tumor growth in vivo via inactivation of IL-6/STAT3 signaling pathway, reflected by the abated abundances of IL-6 and p-STAT3. These data suggested that absence of exosomal miR-25-3p rescued breast cancer aggressiveness through inhibiting cell viability and migration by regulation of IL-6 secretion from macrophages, providing a potential biomarker for breast cancer treatment.

Hypoxia is a major hallmark of solid tumors and is associated with malignant phenotypes.

Effects of alpha lipoic acid and its derivative "andrographolid-lipoic acid-1" on ulcerative colitis: A systematic review with meta-analysis of animal studies

We aimed to review and meta-analyze the inflammatory and oxidative factors following alpha lipoic acid (ALA) and its derivative "andrographolid-lipoic acid-1" (AL-1) in ulcerative colitis (UC). ALA plays an important role in scavenging intracellular radicals and inflammatory elements. AL-1 is found in herbal medicines with potent anti-inflammatory properties. Data were collected from the Google Scholar, PubMed, Scopus, Evidence-based medicine/clinical trials, and Cochrane library database until 2017, which finally resulted in 22 animal studies (70 rats and 162 mice). The beneficial effects of ALA or AL-1 on the most important parameters of UC were reviewed; also, studies were considered separately in mice and rats. Administration of ALA and AL-1 significantly reduced the tumor necrosis factor-α level compared with the controls, while data were not noteworthy in the meta-analysis (mean differences = -18.57 [95% CI = -42.65 to 5.51], P = 0.13). In spite of insignificant decrease in meta-analysis outcomes (differences = 6.92 [95% CI = -39.33 to 53.16], P = 0.77), a significant reduction in myeloperoxidase activity was shown following ALA or AL-1 treatment compared with the controls. Despite significant differences in each study, we had to exclude some studies to homogenize data for meta-analyzing as they showed insignificant results. Interleukin 6, cyclooxygenase-2, glutathione, malondialdehyde, superoxide dismutase, histopathological score, macroscopic and microscopic scores, disease activity index, body weight change, and colon length were also reviewed. Most studies have emphasized on significant positive effects of ALA and AL-1. Comprehensive clinical trials are obligatory to determine the precious position of ALA or AL-1 in the management of UC.

Siji Antiviral Mixture Protects against CA16 Induced Brain Injury through Inhibiting PERK/STAT3/NF-κB Pathway

Coxsackievirus 16 (CA16) causes hand, foot, and mouth disease (HFMD) in young children and infants, and it can lead to fatal neurological complications. This study investigated antiviral effects of Siji Antiviral Mixture (SAM) on CA16 in neonatal mice and the protective effects of SAM on CA16 induced brain injuries. Neonatal BALB/c mice and SH-SY5Y cells were used and injected with CA16 stains to study the efficacy. ELISA and Western blotting were used to measure the cytokines levels and proteins expression. Genes transduction was also used to verify interaction mechanism. As the results shown, SAM could reduce the clinical scores at the beginning and delay disease development in vivo. Treatment with SAM decreased the levels of LDH, CK-MB, caspase 3 and Bax, ER stress, and inflammatory reaction induced by CA16 infection. Further siRNA transfection results showed that CA16 induced ER stress and inflammatory reaction through PERK/STAT3/NF-κB signaling and the protective effects of SAM might be through inhibiting PERK/STAT3/NF-κB signaling. HPLC analysis showed fingerprint profiles of SAM had 42 chromatographic peaks. Collectively, our study highlighted distinct roles of SAM in inhibiting CA16 infection and brain injury. The molecular mechanism of SAM might be through inhibiting PERK/STAT3/NF-κB signaling.

NF-κB upregulation through epigenetic silencing of LDOC1 drives tumor biology and specific immunophenotype in Group A ependymoma

Background

Inflammation has been identified as a hallmark of high-risk Group A (GpA) ependymoma (EPN). Chronic interleukin (IL)-6 secretion from GpA tumors drives an immune suppressive phenotype by polarizing infiltrating monocytes. This study determines the mechanism by which IL-6 is dysregulated in GpA EPN.

Methods

Twenty pediatric GpA and 21 pediatric Group B (GpB) EPN had gene set enrichment analysis for MSigDB Hallmark gene sets performed. Protein and RNA from patients and cell lines were used to validate transcriptomic findings. GpA cell lines 811 and 928 were used for in vitro experiments performed in this study.

Results

The nuclear factor-kappaB (NF-κB) pathway is a master regulator of IL-6 and a signaling pathway enriched in GpA compared with GpB EPN. Knockdown of NF-κB led to significant downregulation of IL-6 in 811 and 928. NF-κB activation was independent of tumor necrosis factor alpha (TNF-α) stimulation in both cell lines, suggesting that NF-κB hyperactivation is mediated through an alternative mechanism. Leucine zipper downregulated in cancer 1 (LDOC1) is a known transcriptional repressor of NF-κB. In many cancers, LDOC1 promoter is methylated, which inhibits gene transcription. We found decreased LDOC1 gene expression in GpA compared with GpB EPN, and in other pediatric brain tumors. EPN cells treated with 5AZA-DC, demethylated LDOC1 regulatory regions, upregulated LDOC1 expression, and concomitantly decreased IL-6 secretion. Stable knockdown of LDOC1 in EPN cell lines resulted in a significant increase in gene transcription of v-rel avian reticuloendotheliosis viral oncogene homolog A, which correlated to an increase in NF-κB target genes.

Conclusion

These results suggest that epigenetic silencing of LDOC1 in GpA EPN regulates tumor biology and drives inflammatory immune phenotype.

Immunostimulatory CpG on Carbon Nanotubes Selectively Inhibits Migration of Brain Tumor Cells

Even when treated with aggressive current therapies, patients with glioblastoma usually survive less than two years and exhibit a high rate of recurrence. CpG is an oligonucleotide that activates the innate immune system via Toll-like receptor 9 (TLR9) activation. Injection of CpG into glioblastoma tumors showed promise as an immunotherapy in mouse models but proved disappointing in human trials. One aspect of glioma that is not addressed by CpG therapy alone is the highly invasive nature of glioma cells, which is associated with resistance to radiation and chemotherapy. Here, we demonstrate that single-walled carbon nanotubes noncovalently functionalized with CpG (SWNT/CpG), which retain the immunostimulatory property of the CpG, selectively inhibit the migration of glioma cells and not macrophages without affecting cell viability or proliferation. SWNT/CpG also selectively decreased NF-κB activation in glioma cells, while activating macrophages by induction of the TLR9/NF-κB pathway, as we have previously reported. The migration inhibition of glioma cells was correlated with selective reduction of intracellular levels of reactive oxygen species (ROS), suggesting that an antioxidant-based mechanism mediates the observed effects. To the best of our knowledge, SWNT/CpG is the first nanomaterial that inhibits the migration of cancer cells while stimulating the immune system.

MicroRNA-31 is required for astrocyte specification

Previously, we determined microRNA-31 (miR-31) is a noncoding tumor suppressive gene frequently deleted in glioblastoma (GBM); miR-31 suppresses tumor growth, in part, by limiting the activity of NF-κB. Herein, we expand our previous studies by characterizing the role of miR-31 during neural precursor cell (NPC) to astrocyte differentiation. We demonstrate that miR-31 expression and activity is suppressed in NPCs by stem cell factors such as Lin28, c-Myc, SOX2 and Oct4. However, during astrocytogenesis, miR-31 is induced by STAT3 and SMAD1/5/8, which mediate astrocyte differentiation. We determined miR-31 is required for terminal astrocyte differentiation, and that the loss of miR-31 impairs this process and/or prevents astrocyte maturation. We demonstrate that miR-31 promotes astrocyte development, in part, by reducing the levels of Lin28, a stem cell factor implicated in NPC renewal. These data suggest that miR-31 deletions may disrupt astrocyte development and/or homeostasis.

Loss of SOCS3 in myeloid cells prolongs survival in a syngeneic model of glioma

In glioma, microglia and macrophages are the largest population of tumor-infiltrating cells, referred to as glioma associated macrophages (GAMs). Herein, we sought to determine the role of Suppressor of Cytokine Signaling 3 (SOCS3), a negative regulator of Signal Transducer and Activator of Transcription 3 (STAT3), in GAM functionality in glioma. We utilized a conditional model in which SOCS3 deletion is restricted to the myeloid cell population. We found that SOCS3-deficient bone marrow-derived macrophages display enhanced and prolonged expression of pro-inflammatory M1 cytokines when exposed to glioma tumor cell conditioned medium in vitro. Moreover, we found that deletion of SOCS3 in the myeloid cell population delays intracranial tumor growth and increases survival of mice bearing orthotopic glioma tumors in vivo. Although intracranial tumors from mice with SOCS3-deficient myeloid cells appear histologically similar to control mice, we observed that loss of SOCS3 in myeloid cells results in decreased M2 polarized macrophage infiltration in the tumors. Furthermore, loss of SOCS3 in myeloid cells results in increased CD8+ T-cell and decreased regulatory T-cell infiltration in the tumors. These findings demonstrate a beneficial effect of M1 polarized macrophages on suppressing glioma tumor growth, and highlight the importance of immune cells in the tumor microenvironment.

Musashi-1 regulates AKT-derived IL-6 autocrinal/paracrinal malignancy and chemoresistance in glioblastoma

Glioblastoma multiform (GBM) is one of the most lethal human malignant brain tumors with high risks of recurrence and poor treatment outcomes. The RNA-binding protein Musashi-1 (MSI1) is a marker of neural stem/progenitor cells. Recent study showed that high expression level of MSI1 positively correlates with advanced grade of GBM, where MSI1 increases the growth of GBM. Herein, we explore the roles of MSI1 as well as the underlying mechanisms in the regulation of drug resistance and tumorigenesis of GBM cells. Our results demonstrated that overexpression of MSI1 effectively protected GBM cells from drug-induced apoptosis through down-regulating pro-apoptotic genes; whereas inhibition of AKT withdrew the MSI1-induced anti-apoptosis and cell survival. We further showed that MSI1 robustly promoted the secretion of the pro-inflammatory cytokine IL-6, which was governed by AKT activity. Autonomously, the secreted IL-6 enhanced AKT activity in an autocrine/paracrine manner, forming a positive feedback regulatory loop with the MSI1-AKT pathway. Our results conclusively demonstrated a novel drug resistance mechanism in GBM cells that MSI1 inhibits drug-induced apoptosis through AKT/IL6 regulatory circuit. MSI1 regulates both cellular signaling and tumor-microenvironmental cytokine secretion to create an intra- and intercellular niche for GBM to survive from chemo-drug attack.

Tricyclic Antidepressants Modulate Stressed Mitochondria in Glioblastoma Multiforme Cells

A common feature of solid tumors, including glioblastoma multiforme (GBM), is mitochondrial dysfunction. However, it is reported that the current standard of anti-GBM therapies may potentiate mitochondrial damage and, in effect, support the aggressive character of cancer. As mitochondria are implicated in the modulation of cellular drug sensitivity and chemoresistance mechanisms, activation-stressed mitochondria in GBM cells may represent a new target for anti-GBM therapy that is nontoxic for normal cells.

METHODS

As mitochondria are possible targets for antidepressant drugs used as adjuvant therapy in patients with GBM, we examined their influence on mitochondrial volume and activity, reactive oxygen species level, extracellular lactate concentration, and p65 NF-κB gene expression in GBM cells.

RESULTS

Our investigation showed, for the first time, that tricyclic antidepressants, imipramine and amitriptyline, partially reverse GBM abnormalities.

CONCLUSION

In the light of reported studies, the mitochondrial disturbance observed in glioma cells is a dynamic process that can be reversed or silenced. Moreover, imipramine and amitriptyline are attractive cellular metabolic modulators and can potentially be used to restoring a proper function of mitochondria in GBM cells.

Knockdown of long non-coding RNA H19 inhibits multiple myeloma cell growth via NF-κB pathway

Long non-coding RNAs (lncRNAs) are implicated in the complex network of cancer including Multiple myeloma (MM) and play important roles in tumor development. lncH19 was significantly up-regulated in multiple cancer types, suggesting it is a potential oncogene. However, the exact functions and downstream mechanisms are largely unknown. This study aimed to investigate whether H19 participates in the cell growth of MM and elucidate the underlying mechanism. We found that H19 was abnormally overexpressed in MM cell lines and sorted CD138⁺ MM bone marrow tissues. H19 knockdown induced by shRNA transfection significantly inhibited proliferation, viability and colony formation in MM cells, as well as inactivated NF-κB pathway. Moreover, combination treatment of H19 knockdown and NF-κB suppression (induced by specific inhibitor PDTC) produced synergistically inhibitory effects. Bone marrow expression of H19 was positively associated with circulating IL-6 or IL-8 level in the same MM patients. And patients with high expression of H19 had a lower survival rate. Taken together, we confirmed the abnormal upregulation of a novel lncRNA, H19, in human MM. H19 was involved in MM cell growth. The linkage between H19 and NF-κB pathway may provide a novel interpretation for the mechanism of H19's growth regulation in MM.

NFAT1-regulated IL6 signalling contributes to aggressive phenotypes of glioma

Background

We previously demonstrated that the local immune status correlated with the glioma prognosis. Interleukin-6 (IL6) was identified as an important local immune-related risk marker related to unfavourable prognosis. In this study, we further investigated the role and regulation of IL6 signalling in glioma.

Methods

The expression and prognostic value of IL6 and the IL6 receptor (IL6R) were explored in The Cancer Genome Atlas (TCGA) and REMBRANDT databases and clinical samples. Functional effects of genetic knockdown and overexpression of IL6R or IL6 stimulation were examined in vitro and in tumours in vivo. The effects of the nuclear factor of activated T cells-1 (NFAT1) on the promoter activities of IL6R and IL6 were also examined.

Results

High IL6- and IL6R-expression were significantly associated with mesenchymal subtype and IDH-wildtype gliomas, and were predictors of poor survival. Knockdown of IL6R decreased cell proliferation, invasion and neurosphere formation in vitro, and inhibited tumorigenesis in vivo. IL6R overexpression or IL6 stimulation enhanced the invasion and growth of glioma cells. TCGA database searching revealed that IL6- and IL6R-expression were correlated with that of NFAT1. In glioma cells, NFAT1 enhanced the promoter activities of IL6R and IL6, and upregulated the expression of both IL6R and IL6.

Conclusion

NFAT1-regulated IL6 signalling contributes to aggressive phenotypes of gliomas, emphasizing the role of immunomodulatory factors in glioma malignant progression.

Electronic supplementary material

The online version of this article (10.1186/s12964-017-0210-1) contains supplementary material, which is available to authorized users.

P2Y14 receptor activation decreases interleukin-6 production and glioma GL261 cell proliferation in microglial transwell cultures

Gliomas are rich in extracellular nucleotides that modulate glioma cell production of multiple cytokines including interleukin (IL)-6, which strongly contributes to glioma cell proliferation. However, little is known about how nucleotide signaling modulates microglial/macrophage (MG/MP) cytokine production in the context of gliomas, nor how MG/MP purinergic P2 receptor expression changes in the tumor micro-environment. We hypothesized that: (1) expression of key P2Y receptors will be augmented in glioma-derived MG/MP, and (2) selective activation of these receptors in vitro will regulate microglial production of IL-6 and glioma cell proliferation. We tested these hypotheses using the murine GL261 glioma model. Compared to MG/MP isolated from the normal brain tissue, CD11b⁺ cells isolated from GL261 tumors expressed higher levels of several P2 receptors, including P2Y14 receptors. To evaluate microglial P2Y14 receptor function in the context of tumor cells, we first cultured N9 microglia in transwells with GL261 cells and found that microglial P2Y14 mRNA levels were similarly increased in transwell cultures. GL261 cells did not express detectable P2Y14 levels either when they were cultured alone or in transwell cultures with N9 cells. Selective P2Y14 receptor activation with UDP-glucose (UDPG) did not affect IL-6 levels in either cell type cultured alone, but in transwell cultures, UDPG decreased IL-6 protein levels in the medium. Application of conditioned medium from UDPG-treated microglia reduced GL261 cell proliferation. Together, these data suggest that P2Y14 receptors may be a key a receptor involved in glioma cell-MG/MP communication in the tumor environment.

Detailed longitudinal sampling of glioma stem cells in situ reveals Chr7 gain and Chr10 loss as repeated events in primary tumor formation and recurrence

Intratumoral heterogeneity at the genetic, epigenetic, transcriptomic, and morphologic levels is a commonly observed phenomenon in many aggressive cancer types. Clonal evolution during tumor formation and in response to therapeutic intervention can be predicted utilizing reverse engineering approaches on detailed genomic snapshots of heterogeneous patient tumor samples. In this study, we developed an extensive dataset for a GBM case via the generation of polyclonal and monoclonal glioma stem cell lines from initial diagnosis, and from multiple sections of distant tumor locations of the deceased patient's brain following tumor recurrence. Our analyses revealed the tissue-wide expansion of a new clone in the recurrent tumor and chromosome 7 gain and chromosome 10 loss as repeated genomic events in primary and recurrent disease. Moreover, chromosome 7 gain and chromosome 10 loss produced similar alterations in mRNA expression profiles in primary and recurrent tumors despite possessing other highly heterogeneous and divergent genomic alterations between the tumors. We identified ETV1 and CDK6 as putative candidate genes, and NFKB (complex), IL1B, IL6, Akt and VEGF as potential signaling regulators, as potentially central downstream effectors of chr7 gain and chr10 loss. Finally, the differences caused by the transcriptomic shift following gain of chromosome 7 and loss of chromosome 10 were consistent with those generally seen in GBM samples compared to normal brain in large-scale patient-tumor data sets.

TGFβ signaling is associated with changes in inflammatory gene expression and perineuronal net degradation around inhibitory neurons following various neurological insults

Brain damage due to stroke or traumatic brain injury (TBI), both leading causes of serious long-term disability, often leads to the development of epilepsy. Patients who develop post-injury epilepsy tend to have poor functional outcomes. Emerging evidence highlights a potential role for blood-brain barrier (BBB) dysfunction in the development of post-injury epilepsy. However, common mechanisms underlying the pathological hyperexcitability are largely unknown. Here, we show that comparative transcriptome analyses predict remodeling of extracellular matrix (ECM) as a common response to different types of injuries. ECM-related transcriptional changes were induced by the serum protein albumin via TGFβ signaling in primary astrocytes. In accordance with transcriptional responses, we found persistent degradation of protective ECM structures called perineuronal nets (PNNs) around fast-spiking inhibitory interneurons, in a rat model of TBI as well as in brains of human epileptic patients. Exposure of a naïve brain to albumin was sufficient to induce the transcriptional and translational upregulation of molecules related to ECM remodeling and the persistent breakdown of PNNs around fast-spiking inhibitory interneurons, which was contingent on TGFβ signaling activation. Our findings provide insights on how albumin extravasation that occurs upon BBB dysfunction in various brain injuries can predispose neural circuitry to the development of chronic inhibition deficits.

Mast cells modulate proliferation, migration and stemness of glioma cells through downregulation of GSK3β expression and inhibition of STAT3 activation

Glioblastoma (GBM) heterogeneity is the main obstacle to efficient treatment due to the existence of subpopulation of cells with increased tumorigenicity and network of tumor associated parenchymal cells in the tumor microenvironment. We previously demonstrated that mast cells (MCs) infiltrate mouse and human gliomas in response to variety of signals in a glioma grade-dependent manner. However, the role of MCs in glioma development and the mechanisms behind MCs-glioma cells interaction remain unidentified. In the present study, we show that MCs upon activation by glioma cells produce soluble factors including IL-6, which are documented to be involved in cancer-related activities. We observe 'tumor educated' MCs decrease glioma cell proliferation and migration, reduce self-renewal capacity and expression of stemness markers but in turn promote glioma cell differentiation. 'Tumor educated' MC derived mediators exert these effects via inactivation of STAT3 signaling pathway through GSK3β down-regulation. We identified 'tumor educated' MC derived IL-6 as one of the contributors among the complex mixture of MCs mediators, to be partially involved in the observed MC induced biological effect on glioma cells. Thus, MC mediated abolition of STAT3 signaling hampers glioma cell proliferation and migration by suppressing their stemness and inducing differentiation via down-regulation of GSK3β expression. Targeting newly identified inflammatory MC-STAT3 axis could contribute to patient tailored therapy and unveil potential future therapeutic opportunities for patients.

Blocking epithelial-to-mesenchymal transition in glioblastoma with a sextet of repurposed drugs: the EIS regimen

This paper outlines a treatment protocol to run alongside of standard current treatment of glioblastoma- resection, temozolomide and radiation. The epithelial to mesenchymal transition (EMT) inhibiting sextet, EIS Regimen, uses the ancillary attributes of six older medicines to impede EMT during glioblastoma. EMT is an actively motile, therapy-resisting, low proliferation, transient state that is an integral feature of cancers’ lethality generally and of glioblastoma specifically. It is believed to be during the EMT state that glioblastoma’s centrifugal migration occurs. EMT is also a feature of untreated glioblastoma but is enhanced by chemotherapy, by radiation and by surgical trauma. EIS Regimen uses the antifungal drug itraconazole to block Hedgehog signaling, the antidiabetes drug metformin to block AMP kinase (AMPK), the analgesic drug naproxen to block Rac1, the anti-fibrosis drug pirfenidone to block transforming growth factor-beta (TGF-beta), the psychiatric drug quetiapine to block receptor activator NFkB ligand (RANKL) and the antibiotic rifampin to block Wnt- all by their previously established ancillary attributes. All these systems have been identified as triggers of EMT and worthy targets to inhibit. The EIS Regimen drugs have a good safety profile when used individually. They are not expected to have any new side effects when combined. Further studies of the EIS Regimen are needed.

Lactobacillus fermentum IM12 attenuates inflammation in mice by inhibiting NF-κB-STAT3 signalling pathway

In the present study, we isolated Lactobacillus fermentum IM12 from human gut microbiota, which strongly inhibited interleukin (IL)-6 expression and STAT3 activation in lipopolysaccharide (LPS)-stimulated murine peritoneal macrophages, and examined its anti-inflammatory effect in mice with carrageenan-induced hind-paw oedema (CIE) or 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitis (TIC). Oral administration of IM12 (0.2×109, 1×109 or 5×109 cfu/mouse, once a day for 3 days) in mice with CIE significantly suppressed the increase of oedema volume and thickness, as well as myeloperoxidase activity and IL-6, IL-17, NO, and prostaglandin E2 levels in the carrageenan-stimulated paw. Treatment with IM12 (1×109 cfu/mouse, once a day for 3 days) in mice with TIC significantly suppressed colon shortening, and myeloperoxidase activity and IL-6 and IL-17 levels. Treatment with IM12 in mice with CIE or TIC also suppressed the expression of inducible NO synthase (iNOS) and cyclooxygenase (COX)-2, as well as activation of nuclear factor kappa beta (NF-κB) and signal transducer and activator of transcription 3 (STAT3). Furthermore, IM12 significantly inhibited the expression of iNOS, and COX-2, as well as activation of NF-κB in LPS-stimulated mouse peritoneal macrophages. The inflammatory effect of heat-inactivated IM12 was significantly different to that of live IM12 in mice with TIC, although anti-inflammatory effect of IM12 was reduced by heat treatment. Based on these findings, IM12 may attenuate inflammation by inhibiting NF-κB-STAT3 signalling pathway.

Inflammatory factor TNF-α promotes the growth of breast cancer via the positive feedback loop of TNFR1/NF-κB (and/or p38)/p-STAT3/HBXIP/TNFR1

In the connection between inflammation and cancer development, tumor necrosis factor-alpha (TNF-α) contributes to the tumorigenesis. However, the underlying mechanism remains poorly understood. In this study, we report that TNF-α enhances the growth of breast cancer through up-regulation of oncoprotein hepatitis B X-interacting protein (HBXIP). Our data showed that the levels of TNF-α were positively related to those of HBXIP in clinical breast cancer tissues. Moreover, TNF-α could up-regulate HBXIP in breast cancer cells. Interestingly, silencing of TNF-α receptor 1 (TNFR1) blocked the effect of TNF-α on HBXIP. Mechanistically, we revealed that TNF-α could increase the activities of HBXIP promoter through activating transcriptional factor signal transducer and activator of transcription 3 (STAT3). In addition, nuclear factor kappa B (NF-κB) and/or p38 signaling increased the levels of p-STAT3 in the cells. Strikingly, HBXIP could also up-regulate TNFR1, forming a positive feedback loop of TNFR1/NF-κB (and/or p38)/p-STAT3/HBXIP/TNFR1. Notably, TNF-α was able to up-regulate TNFR1 through driving the loop. In function, we demonstrated that the knockdown of HBXIP remarkably abolished the growth of breast cancer mediated by TNF-α in vitro and in vivo. Thus, we conclude that TNF-α promotes the growth of breast cancer through the positive feedback loop of TNFR1/NF-κB (and/or p38)/p-STAT3/HBXIP/TNFR1.Our finding provides new insights into the mechanism by which TNF-α drives oncoprotein HBXIP in the development of breast cancer.

Down-regulation of Forkhead box protein A1 (FOXA1) leads to cancer stem cell-like properties in tamoxifen-resistant breast cancer cells through induction of interleukin-6

The selective estrogen receptor (ER) modulator tamoxifen inhibits ER signaling in breast cancer cells, and it is used for the treatment of ER-positive breast cancer. However, this type of cancer often acquires resistance to tamoxifen, and a better understanding of the molecular mechanisms underlying tamoxifen resistance is required. In this study, we established tamoxifen-resistant (TAM-R) breast cancer cells by long-term tamoxifen treatment of ER-positive breast cancer MCF7 cells. In TAM-R cells, expression of not only ERα, a major form of ER in breast cancer, but also its transcriptional partner forkhead box protein A1 (FOXA1) was found to be reduced. In contrast, activation of the transcription factor nuclear factor-κB (NF-κB) and expression of its target IL6 were increased in these cells. Stable expression of FOXA1, but not ERα, reduced the expression of IL6 in the FOXA1- and ERα-negative breast cancer MDA-MB-231 cells and TAM-R cells, without affecting the activation of the NF-κB signaling pathways. Conversely, FOXA1 knockdown induced IL6 expression in MCF7 cells. Chromatin immunoprecipitation assays revealed that FOXA1 bound to the promoter region of IL6 and repressed recruitment of the NF-κB complex to this region. TAM-R cells were found to have high mammosphere-forming activity, characteristics of cancer stem cells, and this activity was suppressed by NF-κB and IL6 signaling inhibitors. Taken together, these results suggest that FOXA1 suppresses expression of IL6 through inhibition of NF-κB recruitment to the IL6 promoter in an ERα-independent manner and that reduction in FOXA1 expression induces IL6 expression and contributes to cancer stem cell-like properties in TAM-R cells.

Preferential expression of functional IL-17R in glioma stem cells: potential role in self-renewal

Gliomas are the most common primary brain tumor and one of the most lethal solid tumors. Mechanistic studies into identification of novel biomarkers are needed to develop new therapeutic strategies for this deadly disease. The objective for this study was to explore the potential direct impact of IL-17−IL-17R interaction in gliomas. Immunohistochemistry and flow cytometry analysis of 12 tumor samples obtained from patients with high grade gliomas revealed that a considerable population (2–19%) of cells in all malignant gliomas expressed IL-17RA, with remarkable co-expression of the glioma stem cell (GSC) markers CD133, Nestin, and Sox2. IL-17 enhanced the self-renewal of GSCs as determined by proliferation and Matrigel^® colony assays. IL-17 also induced cytokine/chemokine (IL-6, IL-8, interferon-γ-inducible protein [IP-10], and monocyte chemoattractant protein-1 [MCP-1]) secretion in GSCs, which were differentially blocked by antibodies against IL-17R and IL-6R. Western blot analysis showed that IL-17 modulated the activity of signal transducer and activator of transcription 3 (STAT3), nuclear factor κ-light-chain-enhancer of activated B cells (NF-κB), glycogen synthase kinase-3β (GSK-3β) and β-catenin in GSCs. While IL-17R-mediated secretion of IL-6 and IL-8 were significantly blocked by inhibitors of NF-κB and STAT3; NF-κB inhibitor was more potent than STAT3 inhibitor in blocking IL-17-induced MCP-1 secretion. Overall, our results suggest that IL-17–IL-17R interaction in GSCs induces an autocrine/paracrine cytokine feedback loop, which may provide an important signaling component for maintenance/self-renewal of GSCs via constitutive activation of both NF-κB and STAT3. The results also strongly implicate IL-17R as an important functional biomarker for therapeutic targeting of GSCs.

STAT3/NF-κB-Regulated Lentiviral TK/GCV Suicide Gene Therapy for Cisplatin-Resistant Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) represents approximately 20% of all breast cancers and appears resistance to conventional cytotoxic chemotherapy, demonstrating a particularly poor prognosis and a significantly worse clinical outcome than other types of cancer. Suicide gene therapy has been used for the in vivo treatment of various solid tumors in recent clinical trials. In tumor microenvironment, STAT3/NF-κB pathways are constitutively activated in stromal cells as well as in cancer stem cells (CSCs). In this study, we have cloned a novel STAT3/NF-κB-based reporter system to drive the expression of herpes simplex virus thymidine kinase (HSV-TK) against breast cancer. Lentiviral vector expressing HSV-TK under the regulation of STAT3/NF-κB fused response element was developed. In this setting, we exploited the constitutive STAT3/NF-κB activation in tumors to achieve higher transgene expression than that driven by a constitutively active CMV promotor in vivo. An orthotropic MDA-MB-231 triple negative breast cancer mouse model was used for evaluating the feasibility of STAT3-NF-κB-TK/GCV suicide gene therapy system.

The basal promoter activity of Lenti-CMV-TK and Lenti-STAT3-NF-κB-TK in MDA-MB-231 cells was compared by ³H-FEAU uptake assay. The Lenti-CMV-TK showed ~5 fold higher ³H-FEAU uptake then Lenti -STAT3-NF-κB-TK. In clonogenic assay, cells expressing Lenti-CMV-TK were 2-fold more sensitive to GCV than Lenti-STAT3-NF-κB-TK transduced cells. In vitro effect of STAT3-NF-κB-induced transgene expression was determined by 10ng/mL TNF-α induction and confirmed by western blot analysis and DsRedm fluorescent microscopy. In vivo evaluation of therapeutic effect by bioluminescence and [¹⁸F]FHBG microPET imaging indicated that Lenti-STAT3-NF-κB-TK showed more tumor growth retardation than Lenti-CMV-TK when GCV (20 mg/kg) was administered. The invasiveness and expression of cancer stem cell markers were both decreased after STAT3/NF-κB-regulated HSV-TK/GCV therapy. Moreover, STAT3/NF-κB signaling targeting could further sensitize tumor cells to cisplatin. This study successfully established a theranositic approach to treat triple-negative breast cancer via STAT3-NF-κB responsive element-driven suicide gene therapy. This platform may also be an alternative strategy to handle with drug-resistant cancer cells.

WITHAFERIN A INDUCES APOPTOSIS IN RAT C6 GLIOMA CELLS THROUGH REGULATING NF-KB NUCLEAR TRANSLOCATION AND ACTIVATION OF CASPASE CASCADE

BACKGROUND

The demand for the chemopreventive drug from the plant source is increasing in recent times, owing to its various biological activities without any adverse effect. The intention of this current study was to examine the anti-glioma effect of Withaferin A (WFA) on C6 glioma cell line model.

MATERIALS AND METHODS

C6 glioma cells were administrated with different concentration of WFA (50, 100, 200 and 500 μg/mL) and DMSO (control) group to examine its anti-proliferative, anti-inflammatory and pro-apoptotic activities.

RESULTS

Treatment with WFA showed a significant decline in the glioma cell count in a dose-dependent manner and thus proving its anti-proliferative effect. Similarly, inflammatory markers were also substantially lowered upon treatment with different concentration of WFA. However, DNA fragmentation and apoptotic markers like Caspase-3 and 9 were concomitantly enhanced after co-cultured with different concentration of WFA and thus exhibiting its cytotoxicity efficacy. Furthermore, the protein expression of Bcl2 and Bax were markedly downregulated and upregulated respectively; upon treatment with WFA on C6 glioma cells.

CONCLUSION

The outcome of this study evidently demonstrates that C6 glioma cells co-cultured with increased concentration of WFA, showed an anti-proliferative, anti-inflammatory and pro-apoptotic effect in a dose-dependent fashion.

Inflammatory landscape of human brain tumors reveals an NFκB dependent cytokine pathway associated with mesenchymal glioblastoma

The tumor microenvironment is being increasingly recognized as a key factor in cancer aggressiveness. In this study, we characterized the inflammatory gene signatures altered in glioma cell lines and tumor specimens of differing histological and molecular subtypes. The results showed that glioblastoma multiforme (GBM) shows upregulation of a subset of inflammatory genes when compared to astrocytomas and oligodendrogliomas. With molecular subtypes of GBM, the expression of inflammatory genes is heterogeneous, being enriched in mesenchymal and downregulated in Proneural/GCIMP. Other inflammation-associated processes such as tumor-associated macrophage (TAM) signatures are upregulated in mesenchymal, and a subset of 33 mesenchymal-enriched inflammatory and TAM markers showed correlation with poor survival. We found that various GBM tumor-upregulated genes such as IL6, IL8 and CCL2 are also actively expressed in glioma cell lines, playing differential and cooperative roles in promoting proliferation, invasion, angiogenesis and macrophage polarization in vitro. These genes can be stimulated by pathways typically altered in GBM, including the EGFR, PDGFR, MEK1/2-ERK1/2, PI3K/Akt and NFκB cascades. Taken together, the results presented herein depict some inflammatory pathways altered in gliomas and highlight potentially relevant targets to therapy improvement.

Rifampicin attenuates experimental autoimmune encephalomyelitis by inhibiting pathogenic Th17 cells responses

Rifampicin, a broad‐spectrum antibiotic, has neuroprotective, immunosuppressive, and anti‐inflammatory properties. However, the effect of rifampicin on autoimmune disorders of the nervous system is not clear. In this study, we investigated whether rifampicin was beneficial to myelin oligodendrocyte glycoprotein peptide (MOG_33–35)‐induced female C57BL/6 experimental autoimmune encephalomyelitis (EAE) mice, the well‐established animal model of multiple sclerosis. Rifampicin treatment (daily from the first day after EAE immunization) remarkably attenuated clinical signs and loss of body weight, which are associated with suppression of inflammatory infiltration and demyelination in spinal cords of EAE mice. Furthermore, rifampicin dramatically reduced the disruption of blood–brain barrier integrity, down‐regulated serum concentration of IL‐6 and IL‐17A, inhibited pathological Th17 cell differentiation, and modulated the expression of p‐STAT3 and p‐p65. These results suggest that rifampicin is effective for attenuating the clinical severity of EAE mice, which may be related to its inhibitive ability in differentiation of Th17 cell and secretion of its key effector molecule IL‐17A via regulation of excessive activation of the key signaling molecules of JAK/STAT pathway. Our findings may be helpful for developing therapeutic and preventive strategies for multiple sclerosis.

Withaferin A and its potential role in glioblastoma (GBM)

Within the Ayurvedic medical tradition of India, Ashwagandha (Withania somnifera) is a well-known herb. A large number of withanolides have been isolated from both its roots and its leaves and many have been assessed for their pharmacological activities. Amongst them, Withaferin A is one of its most bioactive phytoconstituents. Due to the lactonal steroid's potential to modulate multiple oncogenic pathways, Withaferin A has gained much attention as a possible anti-neoplastic agent. This review focuses on the use of Withaferin A alone, or in combination with other treatments, as a newer option for therapy against the most aggressive variant of brain tumors, Glioblastoma. We survey the various studies that delineate Withaferin A's anticancer mechanisms, its toxicity profiles, its pharmacokinetics and pharmacodynamics and its immuno-modulating properties.

Activation of GPER suppresses migration and angiogenesis of triple negative breast cancer via inhibition of NF-κB/IL-6 signals

Triple-negative breast cancer (TNBC) is characterized by high vascularity and frequent metastasis. Here, we found that activation of G protein-coupled estrogen receptor (GPER) by its specific agonist G-1 can significantly inhibit interleukin 6 (IL-6) and vascular endothelial growth factor A (VEGF-A). TNBC tissue microarrays from 100 TNBC patients revealed GPER is negatively associated with IL-6 levels and higher grade and stage. Activation of GPER or anti-IL-6 antibody can inhibit both in vitro tube formation of human umbilical vein endothelial cells (HUVECs) and migration of TNBC cells. While recombinant IL-6 supplementary can significantly reverse the inhibitory effects of G-1, suggesting the essential role of IL-6 in G-1 induced suppression of angiogenesis and invasiveness of TNBC cells. G-1 treatment decreased the phosphorylation, nuclear localization, transcriptional activities of NF-κB and suppressed its binding with IL-6 promoter. BAY11-7028, the inhibitor of NF-κB, can mimic the effect of G-1 to suppression of IL-6 and VEGF-A. While over expression of p65 can attenuate the inhibitory effects of G-1 on IL-6 and VEGF expression. The suppression of IL-6 by G-1 can further inhibit HIF-1α and STAT3 signals in TNBC cells by inhibition their expression, phosphorylation and/or nuclear localization. Moreover, G-1 also inhibited the in vivo NF-κB/IL-6 signals and angiogenesis and metastasis of MDA-MB-231 xenograft tumors. In conclusion, our study demonstrated that activation of GPER can suppress migration and angiogenesis of TNBC via inhibition of NF-κB/IL-6 signals, therefore it maybe act as an important target for TNBC treatment.

Suppressor of cytokine signaling 3 plays an important role in porcine circovirus type 2 subclinical infection by downregulating proinflammatory responses

Porcine circovirus type 2 (PCV2) causes porcine circovirus-associated diseases and usually evokes a subclinical infection, without any obvious symptoms, in pigs. It remains unclear how PCV2 leads to a subclinical infection. In this study, we found that peripheral blood mononuclear cells (PBMCs) from PCV2-challenged piglets with no significant clinical symptoms exhibited increased expression of suppressor of cytokine signaling (SOCS) 3, but no significant changes in the expression of the proinflammatory cytokines interleukin (IL)-6 and tumor necrosis factor (TNF)-α; this differed from piglets that displayed significant clinical symptoms. IL-6- and TNF-α-mediated signalings were inhibited in PBMCs from subclinical piglets. Elevated SOCS3 levels inhibited IL-6- and TNF-α-mediated NF-kappa-B inhibitor alpha degradation in PBMCs and PK-15 cells. SOCS3 production was also increased in PCV2-infected PK-15 porcine kidney cells, and IL-6 and TNF-α production that was induced by PCV2 in PK-15 cells was significantly increased when SOCS3 was silenced by a small interfering RNA. SOCS3 interacted with signal transducer and activator of transcription 3 and TNF-associated receptor-associated factor 2, suggesting mechanisms by which SOCS3 inhibits IL-6 and TNF-α signaling. We conclude that SOCS3 plays an important role in PCV2 subclinical infection by suppressing inflammatory responses in primary immune cells.

Loss of tumor suppressive microRNA-31 enhances TRADD/NF-κB signaling in glioblastoma

Glioblastomas (GBMs) are deadly tumors of the central nervous system. Most GBM exhibit homozygous deletions of the CDKN2A and CDKN2B tumor suppressors at 9p21.3, although loss of CDKN2A/B alone is insufficient to drive gliomagenesis. MIR31HG, which encodes microRNA-31 (miR-31), is a novel non-coding tumor suppressor positioned adjacent to CDKN2A/B at 9p21.3. We have determined that miR-31 expression is compromised in >72% of all GBM, and for patients, this predicts significantly shortened survival times independent of CDKN2A/B status. We show that miR-31 inhibits NF-κB signaling by targeting TRADD, its upstream activator. Moreover, upon reintroduction, miR-31 significantly reduces tumor burden and lengthens survival times in animal models. As such, our work identifies loss of miR-31 as a novel non-coding tumor-driving event in GBM.

Deletion and low expression of NFKBIA are associated with poor prognosis in lower-grade glioma patients

Lower-grade gliomas (LGGs), which are uniformly fatal in young adults, are classified as grades II-III tumors according to their histological features. The NFκB transcription factor, a crucial player in cancer initiation and progression, is inactivated in the cytoplasm by inhibitory proteins (IκBs) that have been shown to exert tumor-suppressor activity. Therefore, using The Cancer Genome Atlas copy number alteration and RNA-Seq data from 398 patients, we evaluated the association between the expression and dosage of NFKBIA, which encodes IκBα, and the overall malignancy of LGGs. Deletion and low expression of NFKBIA were associated with enhanced tumor aggressiveness and poor prognosis in LGGs. Accordingly, the dosage and expression of NFKBIA were independent prognostic factors for 5-year survival (dosage: P = 0.016; expression: P = 0.002) and 5-year recurrence-free survival (dosage: P = 0.009; expression: P = 0.005). Moreover, gene set enrichment analyses and co-expression network analyses indicated a role for NFKBIA in the negative regulation of cell proliferation, possibly through the modulation of downstream NFκB activation. Overall, the present findings reveal the prognostic value of NFKBIA in LGGs, reinforcing the relevance of NFκB signaling in the development and progression of gliomas.

Insulin-like growth factor binding protein-2 regulates β-catenin signaling pathway in glioma cells and contributes to poor patient prognosis

BACKGROUND

Upregulation of insulin-like growth factor binding protein 2 (IGFBP-2) is often associated with aggressiveness of glioblastoma (GBM) and contributes to poor prognosis for GBM patients. In view of the regulation of β-catenin by IGFBP-2 in breast cancer and the crucial role of β-catenin pathway in glioma invasion, proliferation and maintenance of glioma stem cells, the mechanism of regulation of β-catenin by IGFBP-2, and its role in GBM prognosis was studied.

METHODS

Regulation of the β-catenin pathway was studied by immunocytochemistry, Western blot analysis, luciferase assays, and real-time RT-PCR. The role of IGFBP-2 was studied by subcutaneous tumor xenografts in immunocompromised mice using glioma cells engineered to express IGFBP-2 and its domains. GBM patient tumor tissues (n = 112) were analyzed for expression of IGFBP-2 and β-catenin by immunohistochemistry. Survival analysis was performed employing Cox regression and Kaplan-Meier survival analyses.

RESULTS

IGFBP-2 knockdown in U251, T98G, and U373 or overexpression in LN229 and U87 cells revealed a role for IGFBP-2 in stabilization of β-catenin and regulation of its nuclear functions involving integrin-mediated inactivation of GSK3β. Similar results were obtained upon overexpression of the C-terminal domain of IGFBP-2 but not the N-terminal domain. Subcutaneous xenograft tumors overexpressing either full-length or the C-terminal domain of IGFBP-2 showed larger volume as compared with controls. Coexpression of high levels of IGFBP-2 and β-catenin was associated with worse prognosis (P = .001) in GBM patients.

CONCLUSION

IGFBP-2 potentiates GBM tumor growth by the activation of the β-catenin pathway through its C-terminal domain, and their coexpression possibly contributes to worse patient prognosis.

Cancer development, chemoresistance, epithelial to mesenchymal transition and stem cells: A snapshot of IL-6 mediated involvement

Interleukin-6 (IL-6) is a cytokine present in tumor microenvironment. Elevated level of IL-6 is associated with cancer cell proliferation, angiogenesis and metastasis through fueling STAT3, MAPK and Akt signaling. It promotes epithelial to mesenchymal transition (EMT) through altered expression of N-cadherin, vimentin, snail, twist and E-cadherin leading to cancer metastasis. IL-6 boosts mammosphere formation, self-renewal of stem cells, stemness properties of cancer cells and recruitment of mesenchymal stem cells. IL-6 is also a contributing factor for multidrug resistance in cancer due to gp130/MAPK/STAT3 mediated activation of transcription factors C/EBPβ/δ, overexpression of p-glycoprotein, EMT transition and expansion of stem cells. The in-depth investigation of IL-6 mediated cellular effects and its signaling pathway can provide the new window for future research and clinical development of IL-6 targeted therapy in cancer. Thus, an overview is delivered in this review deciphering the emerging aspect of the predominant influence of IL-6 in malignant transformation, EMT, cancer-associated stem cells and chemoresistance.

Therapeutic CK2 inhibition attenuates diverse prosurvival signaling cascades and decreases cell viability in human breast cancer cells

Breast cancer is the most common malignancy in women worldwide and remains a major cause of mortality, thus necessitating further therapeutic advancements. In breast cancer, numerous cell signaling pathways are aberrantly activated to produce the myriad phenotypes associated with malignancy; such pathways include the PI3K/Akt/mTOR, NF-κB and JAK/STAT cascades. These pathways are highly interconnected, but one prominent lateral enhancer of each is the remarkably promiscuous kinase CK2. CK2 expression has been shown to be elevated in cancer, thus implicating it in tumorigenesis through its effects on oncogenic signaling cascades. In this study, we identify aberrant expression of CK2 subunits in human breast samples from The Cancer Genome Atlas dataset. Additionally, two specific small molecule inhibitors of CK2, CX-4945 and TBB, were used to examine the role of CK2 in two human breast cancer cell lines, MDA-MB-231 and MCF-7 cells. We show that CK2 inhibition attenuates constitutive PI3K/Akt/mTOR, NF-κB and STAT3 activation and inducible NF-κB and JAK/STAT activation and downstream transcriptional activity. CX-4945 treatment caused a range of phenotypic changes in these cell lines, including decreased viability, cell cycle arrest, apoptosis and loss of migratory capacity. Overall, these results demonstrate the tremendous potential of CK2 as a clinical target in breast cancer.