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Cancer 'stemness' is fundamental to cancer existence. It defines the ability of cancer cells to indefinitely perpetuate as well as differentiate. Cancer stem cell populations within a growing tumor also help evade the inhibitory effects of chemo- as well as radiation-therapies, in addition to playing an important role in cancer metastases. NF-κB and STAT-3 are representative transcription factors (TFs) that have long been associated with cancer stemness, thus presenting as attractive targets for cancer therapy. The growing interest in non-coding RNAs (ncRNAs) in the recent years has provided further insight into the mechanisms by which TFs influence cancer stem cell characteristics. There is evidence for a direct regulation of TFs by ncRNAs, such as, microRNAs (miRNAs), long non-coding RNAs (lncRNAs) as well as circular RNAs (circRNAs), and vice versa. Additionally, the TF-ncRNAs regulations are often indirect, involving ncRNA-target genes or the sponging of other ncRNA species by individual ncRNAs. The information is rapidly evolving and this review provides a comprehensive review of TF-ncRNAs interactions with implications on cancer stemness and in response to therapies. Such knowledge will help uncover the many levels of tight regulations that control cancer stemness, providing novel opportunities and targets for therapy in the process. [ABSTRACT FROM AUTHOR]

Differentiation of preadipocyte, also called adipogenesis, leads to the phenotype of mature adipocyte. However, excessive adipogenesis is closely linked to the development of obesity. Artesunate, one of artemisinin-type sesquiterpene lactones from Artemisia annua L., is known for anti-malarial and anti-cancerous activities. In this study, we investigated the effect of artesunate on adipogenesis in 3T3-L1 preadipocytes. Artesunate strongly inhibited lipid accumulation and triglyceride (TG) synthesis during the differentiation of 3T3-L1 preadipocytes into adipocytes at 5 µM concentration. Artesunate at 5 µM also reduced not only the expressions of CCAAT/enhancer-binding protein-a (C/EBP-a), peroxisome proliferator-activated receptor-? (PPAR-?), fatty acid synthase (FAS), and perilipin A but also the phosphorylation levels of signal transducer and activator of transcription-3 (STAT-3) during adipocyte differentiation. Moreover, artesunate at 5 µM reduced leptin, but not adiponectin, mRNA expression during adipocyte differentiation. Taken together, these findings demonstrate that artesunate inhibits adipogenesis in 3T3-L1 preadipoytes through the reduced expression and/or phosphorylation levels of C/EBP-a, PPAR-?, FAS, perilipin A, and STAT-3. [ABSTRACT FROM AUTHOR]

Interleukin (IL)-18 is a cytokine previously demonstrated to participate in neuroinflammatory processes. Since the components of the IL-18 receptor complex are expressed in neurons throughout the brain, IL-18 is also believed to directly influence neuronal function. Here we tested this hypothesis on mouse hippocampal neurons by measuring the effects of IL-18 on three pathways previously shown to be regulated by this cytokine in non-neuronal cells: the MAPK pathways, p38 and ERK1/2 MAPKs, STAT3 and NF-κB. Experiments were carried out in vitro using the immortalized hippocampal neuronal line HT-22 or in vivo following i.c.v. injection with recombinant mouse IL-18. We showed that IL-18 did not activate NF-κB in HT-22 cells whereas it induced a rapid (within 15min) activation of the MAPK pathways. Moreover, we demonstrated that IL-18 treatment enhanced P-STAT3 (Tyr705)/STAT3 ratio in the nucleus of HT-22 cells after 30-60min of exposure. A similar increase in P-STAT3 (Tyr705)/STAT3 ratio was observed in the whole hippocampus one hour after i.c.v. injection. These data demonstrate that IL-18 can act directly on neuronal cells affecting the STAT3 pathway; therefore, possibly regulating the expression of specific genes within the hippocampus. This effect may help to explain some of the IL-18-induced effects on synaptic plasticity and functionality within the hippocampal system. [ABSTRACT FROM AUTHOR]

Abstract: Veratric acid, a simple benzoic acid derived from plants and fruits, has been reported to have anti-oxidant, anti-inflammation, and blood pressure-lowering effects. This study was designed to evaluate the inhibitory effects of veratric acid on nitric oxide (NO) production in LPS-stimulated RAW264.7 cells. It was found that veratric acid inhibited NO production and inducible nitric oxide synthase (iNOS) expression in LPS-stimulated RAW264.7 cells. The inhibitory effects of veratric acid on the generation of interleukin-6 (IL-6) and interferon-γ (IFN-γ) was determined. Furthermore, veratric acid facilitated the inactivation of glycogen synthase kinase-3β (GSK-3β), STAT-1, and STAT-3 in dose-dependent manner. Notably, NF-κB and members of the mitogen activated protein kinase (MAPK) family including p38, ERK, and JNK were dephosphorylated by veratric acid. These findings suggest that the treatment of veratric acid might be effective in neutralizing the over-expression of NO in inflammatory disorders. [Copyright &y& Elsevier]

Abstract: Increased microvessel density in atherosclerotic plaques plays a major role in promoting plaque destabilization resulting in increased risk of stroke and myocardial infarction. Previously we have shown that expression of the inflammatory cytokine, Oncostatin-M (OSM), in human atherosclerotic plaques correlated with increased microvessel density, indicating a role for OSM in promoting plaque angiogenesis. The purpose of this study was to determine the mechanism by which OSM regulates Vascular Endothelial Growth Factor (VEGF) expression in human coronary artery smooth muscle cells. Using shRNA and overexpression studies, we have shown that the transcription factor, STAT-1 inhibited VEGF expression, while STAT-3 promoted the expression of VEGF. We further show that the mechanism by which STAT-1 and STAT-3 regulates VEGF expression is through modulation of Hypoxia Inducible Factor-1α (HIF-1α). STAT-1 suppresses HIF-1α expression, whereas STAT-3 positively regulates HIF-1α expression. These results provide evidence that activated STAT-1 and STAT-3 regulate VEGF expression indirectly, by modulating HIF-1α activity. [Copyright &y& Elsevier]

Abstract: Purpose: Based upon promising preclinical and phase 1 trial results, combined flavopiridol and cisplatin therapy was evaluated in patients with ovarian and primary peritoneal cancers. Methods: A two cohort phase 2 trial of cisplatin (60mg/m2 IV) immediately followed by flavopiridol (100mg/m2 IV, 24h infusion; 21day cycles) was undertaken in patients with recurrent platin-sensitive or platin-resistant disease (progression>vs. ≤6months following prior platin-based therapy). Measurable disease (RECIST) - or evaluable disease plus CA125 >2X post-treatment nadir - and ECOG performance ≤2 were required. Results: Forty-five patients were enrolled between December 23, 2004 and February 25, 2010: 40 platin-resistant (Group 1), and 5 platin-sensitive (Group 2). In Group 1 , the median number of treatment cycles was 3 (range 2–12). Only 10% of patients incurred grade 4 toxicities, but grade 3 toxicities were common (65%): neutropenia (17.5%); nausea (12.5%); vomiting, fatigue, thrombosis, anemia (10% each). Seven patients (17.5%) achieved a confirmed response (1 CR, 6 PR; median duration 118days); ten additional patients (25%) attained maintained stable disease. Median time to progression was 4.3months; overall survival was 16.1months. Pilot translational studies assessed ascites flavopiridol level; surrogate marker studies were uninformative. In Group 2 , although 4 of 5 patients responded (2 confirmed PRs with median time to progression, 10.8months and median overall survival 20.6months) the cohort was closed due to poor accrual. Conclusions: The assessed flavopiridol and cisplatin regimen displayed clinical activity in platin resistant and sensitive ovarian/primary peritoneal cancers, meriting further study. [Copyright &y& Elsevier]

Abstract: Several epidemiological studies have indicated that abundant consumption of foods from plant origin is associated with a reduced risk of developing several types of cancers. This chemopreventive effect is related to the high content of these foods in phytochemicals, such as polyphenols, that interfere with several processes involved in cancer progression including tumor cell growth, survival and angiogenesis. In addition to the low intake of plant-based foods, increased body mass and physical inactivity have recently emerged as other important lifestyle factors influencing cancer risk, leading to the generation of low-grade chronic inflammatory conditions which are a key process involved in tumor progression. The objectives of the current study are to investigate the inhibitory effects of these polyphenols on angiogenesis triggered by an inflammatory cytokine (IL-6) and to determine the mechanisms underlying this action. We found that, among the tested polyphenols, apigenin and luteolin were the most potent angiogenesis inhibitors through their inhibitory effect on the inflammatory cytokine IL-6/STAT3 pathway. These effects resulted in modulation of the activation of extracellular signal-regulated kinase-1/2 signaling triggered by IL-6, as well as in a marked reduction in the proliferation, migration and morphogenic differentiation of endothelial cells. Interestingly, these polyphenols also modulated the expression of IL-6 signal transducing receptor (IL-6Rα) and the secretion of the extracellular matrix degrading enzyme MMP-2 as well as the expression of suppressor of cytokine signaling (SOCS3) protein. Overall, these results may provide important new information on the role of diet in cancer prevention. [Copyright &y& Elsevier]

Abstract: Enhancing natural killer (NK) cell activation has been associated with protection from human immunodeficiency virus-1 (HIV-1) infections and slowed onset of immunodeficiency. However, soluble HIV-1 envelope protein, gp120, has been shown to impair NK cell cytokine secretion and cell-mediated cytotoxicity. Here we show that gp120 suppressed IFN-γ production and cytotoxic function of a human NK cell line NK-92MI. We furthermore demonstrated that an anti-inflammatory cytokine interleukin-11 can restore effector functions to repressed NK-92MI cells. These studies support the notion that IL-11 administration may reduce HIV-1-mediated immune activation and exhaustion while achieving elimination of virally-infected cells through restored NK cell function. [Copyright &y& Elsevier]

Abstract: Previous studies have shown that erythropoietin (EPO) is neuroprotective in both in vivo and in vitro models of hypoxia ischemia. However these studies hold limited clinical translations because the underlying mechanism remains unclear and the key molecules involved in EPO-induced neuroprotection are still to be determined. This study investigated if tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) and its upstream regulator signaling molecule Janus kinase-2 (JAK-2) are critical in EPO-induced neuroprotection. Hypoxia ischemia (HI) was modeled in-vitro by oxygen and glucose deprivation (OGD) and in-vivo by a modified version of Rice–Vannucci model of HI in 10-day-old rat pups. EPO treated cells were exposed to AG490, an inhibitor of JAK-2 or TIMP-1 neutralizing antibody for 2h with OGD. Cell death, phosphorylation of JAK-2 and signal transducers and activators of transcription protein-3 (STAT-3), TIMP-1 expression, and matrix metalloproteinase-9 (MMP-9) activity were measured and compared with normoxic group. Hypoxic ischemic animals were treated one hour following HI and evaluated 48h after. Our data showed that EPO significantly increased cell survival, associated with increased TIMP-1 activity, phosphorylation of JAK-2and STAT-3, and decreased MMP-9 activity in vivo and in vitro. EPO''s protective effects were reversed by inhibition of JAK-2 or TIMP-1 in both models. We concluded that JAK-2, STAT-3 and TIMP-1 are key mediators of EPO-induced neuroprotection during hypoxia ischemia injury. [Copyright &y& Elsevier]

Abstract: Malignant astrocytomas are highly vascular neoplasms characterized by a potent angiogenic and immunosuppressive phenotype. Th2-cytokines (IL-6/IL-8) are implicated as major regulators of glioma cell growth and invasiveness. STAT-3, a downstream transducer of cytokine signaling is positively associated with tumor angiogenesis. The present study aimed to investigate the expression of IL-8 and p-STAT-3 in 97 diffusely infiltrating astrocytomas of various grades, in relation to IL-6, VEGF, clinicopathological features, microvascular characteristics and patients’ survival. IL-8 expression was localized in neoplastic cells, being associated with p-STAT-3 (p =0.0013), IL-6 (p =0.0004) and VEGF (p <0.0001) around areas of necrosis as well as in perivascular inflammatory and endothelial cells. All the molecules under study correlated with tumor grade and degree of necrosis (p <0.05, respectively). p-STAT-3, IL-8 and VEGF expression was positively associated with microvessel density (p =0.0491, p <0.0001 and p =0.0118, respectively). Univariate analysis indicated that overexpression of IL-8 and IL-6 adversely affected survival in the entire cohort whereas increased p-STAT-3 expression was predictive of improved survival in high grade (III/IV) astrocytomas (p =0.0032). In multivariate analysis only IL-8 expression (p =0.043) retained its significance. The prognostic significance of IL-8 expression and its correlation with p-STAT-3 and VEGF implicates this novel signaling pathway in astroglial tumors progression providing new targets for effective immunotherapy. [Copyright &y& Elsevier]

Abstract: Autosomal dominant HIES (AD-HIES) is a primary immunodeficiency caused by dominant negative mutations in STAT3 clustered in the DNA binding and SH2 domains. Although in vitro differences in mutational constructs are observed, clinical phenotypic correlates of these genetic changes have not been described. We reviewed the charts of 65 AD-HIES patients (DNA binding n=35; SH2 n=30), recorded the components of the NIH HIES clinical scoring system as well as brain and coronary artery abnormalities and analyzed data by mutation region in adults and children. Patients with SH2 domain mutations had increased frequency of high palate, broad inter-alar distance, upper respiratory tract infections and, in the pediatric sub-group, significant scoliosis. There was suggestion of increased mortality for patients with DNA binding mutations. Although subtle differences in phenotype were observed to depend on the STAT3 genotype, overall the clinical phenotypes were similar between individuals with DNA binding and SH2 domain mutations. [Copyright &y& Elsevier]

Proliferative vitreoretinopathy (PVR) involves retinal pigment epithelium (RPE) cell proliferation and migration and leads to tractional retinal detachment. Demethoxycurcumin (DMC), a curcuminoid, has anti-inflammatory and anti-tumour properties. However, whether DMC affects the migration of RPE cells and the molecular mechanism of human PVR remains unclear. The aim of the current study was to investigate the effects of DMC on the inhibition of migration and proteinase expression of human ARPE-19 cells. Herein, we provided molecular evidence associated with PVR prevention through DMC by inhibiting ARPE-19 cell migration. We performed gelatin zymography, Western blot and RT-PCR and respectively found that DMC is sufficient to reduce matrix metalloproteinase-2 (MMP-2) activity, protein level and mRNA expression. DMC suppressed the nuclear levels of transcriptional factors specificity protein 1 and c-Fos, which are involved in the modulation of the transcriptional activation of the MMP-2 gene. DMC also inhibited STAT-3 phosphorylation in ARPE-19 cells. Selective STAT-3 induction by a STAT-3 activator, colivelin, reverted MMP activity and protein expression and cell migration, which were reduced in response to DMC. The results proved the inhibitory effect of DMC on RPE cell migration and MMP-2 expression by the down-regulation of the STAT-3 signalling pathway. • DMC affects the migration of RPE cells and the molecular mechanism of human PVR remains unclear. • DMC reduces SP-1, c-Fos transcriptional factors and MMP-2 expression. • DMC inhibited STAT-3 phosphorylation in ARPE-19 cells. • DMC may be used as a template to develop a therapeutic agent for PVR. [ABSTRACT FROM AUTHOR]

Abstract: Dominant-negative mutations in STAT-3 have recently been found in the majority of patients with sporadic or autosomal-dominant hyper IgE syndrome (HIES). Since STAT-3 plays a role in B cell development and differentiation, we analyzed memory B cells in 20 patients with HIES, 17 of which had STAT-3 mutations. All but four patients had reduced non-switched and/or class-switched memory B cells. No reduction in these B cell populations was found in 16 atopic dermatitis patients with IgE levels above 1000 KU/L. There was no correlation between the reduction of memory B cells and the ability to produce specific antibodies. Moreover, there was no correlation between the percentage of memory B cells and the infection history. Analysis of memory B cells can be useful in distinguishing patients with suspected HIES from patients with atopic disease, but probably fails to identify patients who are at high risk of infection. [Copyright &y& Elsevier]

Abstract: Hepcidin, a liver peptide, systemically inhibits iron utilization and is downregulated under hypoxic conditions. However, little is known about the mechanism underlying the hypoxic suppression of hepcidin. Here, we tested the possibility that HIF-1 and ROS are involved in hepcidin regulation. Hepcidin mRNA, pre-mRNA, and protein levels were reduced in mouse livers and in HepG2 cells after hypoxic incubation, and HIF-1 overexpression and knock-down studies showed that hepcidin regulation is independent of HIF-1. On the other hand, ROS levels were significantly elevated in hypoxic HepG2 cells, and anti-oxidants prevented the hypoxic down-regulation of hepcidin. Conversely, a prooxidant, H2O2, suppressed hepcidin expression in these cells even in normoxia. Of the various transcription factors examined, C/EBPα and STAT-3 were found to dissociate from hepcidin promoter under hypoxia, but to become fully engaged after anti-oxidant treatment. These results suggest that ROS repress the hepcidin gene by preventing C/EBPα and STAT-3 binding to hepcidin promoter during hypoxia. [Copyright &y& Elsevier]

Cyclooxygenase (COX)-2 expression and prostaglandin E2 (PGE2) secretion are increased in prostatic intraepithelial neoplasia (PIN) and prostate cancer. PGE2 biosynthesis by cyclooxygenase (COX)-2 plays a pivotal role in inflammation and carcinogenesis. One of the critical proinflammatory cytokines in the prostate is interleukin-6 (IL-6). We hypothesized that increased expression of COX-2, with resultant increased levels of PGE2 in human PIN cells, activates the IL-6 signaling pathway. We demonstrate an autocrine upregulation of PGE2 mediated by IL-6 in a human PIN cell line. We further demonstrate that PGE2 stimulates soluble IL-6 receptor (sIL-6R) release, gp130 dimerization, Stat-3 protein phosphorylation, and DNA binding activity. These events, induced by PGE2, lead to increased PIN cell growth. Treatment of PIN cells with a selective COX-2 inhibitor decreases cell growth. Finally, PGE2-stimulated PIN cell growth was abrogated by the addition of IL-6 neutralizing antibodies. These data provide mechanistic evidence that increased expression of COX-2/PGE2 contributes to prostate cancer development and progression via activation of the IL-6 signaling pathway. [Copyright &y& Elsevier]