• Tuberculosis and Respiratory Diseases
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• v.44 no.6
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• pp.1271-1284
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• 1997

Background : Tumor necrosis factor(TNF) has been considered as an important candidate for cancer gene therapy based on its potent anti-tumor activity. However, since the efficiency of current techniques of gene transfer is not satisfactory, the majority of current protocols is aiming the in vitro gene transfer to cancer cells and re-introducing genetically modified cancer cells to host. In the previous study, it was shown that TNF-sensitive cancer cells transfected with TNF-$\alpha$ cDNA would become highly resistant to TNF, and the probability was shown that the acquired resistance to TNF might be associated with synthesis of some protective protein. Understanding the mechanisms of TNF-resistance in TNF-$\alpha$ cDNA transfected cancer cells would be an important step for improving the efficacy of cancer gene therapy as well as for better understandings of tumor biology. This study was designed to evaluate whether the levels of TNF receptor mRNA expression and soluble TNF receptor release from cancer cells are changed after TNF-$\alpha$ cDNA transfection. Method : We transfected TNF-$\alpha$ c-DNA to WEHI164(murine fibrosarcoma cell line), NCI-H2058(human mesothelioma cell line), A549(human non-small cell lung cancer cell line), ME180(human cervix cancer cell line) cells using retroviral vector(pLT12SN(TNF)) and confirm the expression of TNF with PCR, EUSA, MTT assay. Then we determined the TNF resistance of TNF-$\alpha$ cDNA transfected cells(WEHI164-TNF, NCIH2058-TNF, A549-TNF, ME180-TNF) and evaluated the TNF receptor mRNA expression with Northern blot analysis and soluble TNF receptor release with EUSA. Results : The TNF receptor mRNA expressions of parental cells and genetically modified cells were not significantly different. The soluble TNF receptor levels of media from genetically modified cells were lower than those from parental cells. Conclusion : The acquired resistance to TNF after TNF-$\alpha$ cDNA transfection may not be associated with the change in the TNF receptor and the soluble TNF receptor expression.

• BMB Reports
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• v.35 no.1
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• pp.61-66
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• 2002

The TNF receptor-associated factor (TRAF) family is a group of adapter proteins that link a wide variety of cell surface receptors. Including the TNF and IL-1 receptor superfamily to diverse signaling cascades, which lead to the activation of NF-${\kappa}B$ and mitogen-activated protein kinases. In addition, TRAFs interact with a variety of proteins that regulate receptor-induced cell death or survival. Thus, TRAF-mediated signals may directly induce cell survival or interfere with the death receptor-induced apoptosis.

• BMB Reports
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• v.35 no.4
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• pp.371-376
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• 2002

The receptor activator of nuclear factor kappa B (RANK) is a member of the tumor necrosis factor (TNF) receptor superfamily. It plays a critical role in osteoclast differentiaion, lymph node organogenesis, and mammary gland development. The stimulation of RANK causes the activation of transcription factors NF-${\kappa}B$ and activator protein 1 (AP1), and the mitogen activated protein kinase (MAPK) c-Jun N-terminal kinase (JNK). In the signal transduction of RANK, the recruitment of the adaptor molecules, TNF receptor-associated factors (TRAFs), is and initial cytoplasmic event. Recently, the association of the MAPK kinase kinase, transforming growth factor-$\beta$-activated kinase 1 (TAK1), with TRAF6 was shown to mediate the IL-1 signaling to NF-${\kappa}B$ and JNK. We investigated whether or not TAK1 plays a role in RANK signaling. A dominant-negative form of TAK1 was discovered to abolish the RANK-induced activation of AP1 and JNK. The AP1 activation by TRAF2, TRAF5, and TRAF6 was also greatly suppressed by the dominant-negative TAK1. the inhibitory effect of the TAK1 mutant on RANK-and TRAF-induced NF-${\kappa}B$ activation was also observed, but less efficiently. Our findings indicate that TAK1 is involved in the MAPK cascade and NF-${\kappa}B$ pathway that is activated by RANK.

• Journal of Microbiology
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• v.37 no.2
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• pp.111-116
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• 1999

Tumor necrosis factor receptor (TNFR)-associated factor 2 (TRAF2) is known to act as a signal transducer that connects TNFR2 to its downstream effector functions such as proliferation of thymocytes, regulation of gene expression, and cell death. TRAF2 consists of largely two domains, the N-terminal half that contains a signal-emanating region and the C-terminal half that is responsible for binding to the intracellular region of TNFR2. In this study, we examined the possible roles of TRAF2 in granulocyte-macrophage colony-stimulating factor (GM-CSF) gene expression and cell death. A truncated mutant of TRAF2 ( 2-263) that contains only a C-terminal half was generated, and transiently transfected to the A549 cell, a human lung cancer cell line, and L929 cell, a murine TNF-sensitive cell line. GM-CSF mRNA was induced in untransfected A540 cells both in dose- and time-dependent manner upon the exposure of TNF. However, neither the full length TRAF2 nor the mutant altered GM-CSF mRNA production regardless of the presence or absence of TNF. Furthermore, neither TRAF2 versions significantly changed the cytotoxic effect of TNF on L929 cells. These data suggest that TRAF2 may not be involved in the signal transduction pathway for GM-CSF gene induction and cell death mediated by TNF.

• Journal of Life Science
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• v.17 no.1 s.81
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• pp.45-50
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• 2007

This study investigated biological activity of tumor necrosis factor $(TNF)-\alpha$ secreted from smooth muscle cell (SMC) destined for death by expressing Fas associated death domain containing protein (FADD) (FADD-SMC) when the cells are grown without tetracycline in culture medium. In the absence of tetracycline the FADD-SMC secreted approximately 1000 pg/ml $TNF-\alpha$, whereas hardly detectable amount of the cytokine existed in the presence of tetracycline. The culture medium collected from the FADD-SMC grown in the absence of tetracycline increased phosphorylated form of p38 MAPK and up-regulated nuclear factor kappa B (NF-kB). The medium collected without tetracycline also caused death of L929 cells. Depletion of $TNF-\alpha$ with the soluble TNF receptor (sTNFR) inhibited the phosphorylation of p38 MAPK, the up-regulation of NF-kB activity and the death activity of the medium collected from FADD-SMC in the absence of tetracycline. These results indicate that $TNF-\alpha$ secreted from SMC undergoing death is biologically active and can affect cellular function.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.24
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• pp.10591-10596
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• 2015

Background: Tumor necrosis factor (TNF) receptor-associated factor 6 (TRAF6) has been reported to be associated with the development of various cancers. However, the role of TRAF6 in lung cancer remains unclear. Objective: To explore the expression and clinicopathological significance of TRAF6 protein in lung cancer tissues. Materials and Methods: Three hundred and sixty-five lung cancer samples and thirty normal lung tissues were constructed into 3 microarrays. The expression of TRAF6 protein was determined using immunohistochemistry (IHC). Furthermore, correlations between the expression of TRAF6 and clinicopathological parameters were investigated. Results: The expression of TRAF6 in total lung cancer tissues (365 cases), as well as in small cell lung cancer (SCLC, 26 cases) and non-small cell lung cancer (NSCLC, 339 cases) was significantly higher compared with that in normal lung tissues. The ROC curve showed that the area under curve of TRAF6 was 0.663 (95%CI 0.570~0.756) for lung cancer. The diagnostic sensitivity and specificity of TRAF6 were 52.6% and 80%, respectively. In addition, the expression of TRAF6 was correlated with clinical TNM stage, tumor size and lymph node metastasis in all lung cancers. Consistent correlations were also observed for NSCLCs. Conclusions: TRAF6 might be an oncogene and the expression of TRAF6 protein is related to the progression of lung cancer. Thus, TRAF6 might become a target for diagnosis and gene therapy for lung cancer patients.

• Nutrition Research and Practice
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• v.8 no.5
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• pp.516-520
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• 2014

BACKGROUND/OBJECTIVES: Carnosic acid (CA), found in rosemary (Rosemarinus officinalis) leaves, is known to exhibit anti-obesity and anti-inflammatory activities. However, whether its anti-inflammatory potency can contribute to the amelioration of obesity has not been elucidated. The aim of the current study was to investigate the effect of CA on Toll-like receptor 4 (TLR4) pathways in the presence of lipopolysaccharide (LPS) in 3T3-L1 adipocytes. MATERIALS/METHODS: 3T3-L1 adipocytes were treated with CA ($0-20{\mu}M$) for 1 h, followed by treatment with LPS for 30 min; mRNA expression of adipokines and protein expression of TLR4-related molecules were then measured. RESULTS: LPS-stimulated 3T3-L1 adipocytes showed elevated mRNA expression of tumor necrosis factor (TNF)-${\alpha}$, interleukin-6, and monocyte chemoattractant protein-1, and CA significantly inhibited the expression of these adipokine genes. LPS-induced up regulation of TLR4, myeloid differentiation factor 88, TNF receptor-associated factor 6, and nuclear factor-${\kappa}B$, as well as phosphorylated extracellular receptor-activated kinase were also suppressed by pre-treatment of 3T3-L1 adipocytes with CA. CONCLUSIONS: Results of this study suggest that CA directly inhibits TLR4-MyD88-dependent signaling pathways and decreases the inflammatory response in adipocytes.

• Journal of the Korean Society of Food Culture
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• v.33 no.4
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• pp.337-344
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• 2018

Germinated brown rice (GBR, Orysa sartiva L.) has been reported to have anti-obesity and anti-inflammatory effects. However, the mechanisms underlying these effects in adipocytes are not fully understood. Therefore, this study was conducted to explore the anti-inflammatory mechanisms of GBR on lipopolysaccharide (LPS)-stimulated 3T3-L1 adipocytes. 3T3-L1 adipocytes were pretreated with GBR extracts (0-20 mg/mL) 1 h before LPS stimulation. The mRNA expression of adipokines and Toll-like receptor 4 (TLR4) were measured by RT-PCR. The protein expressions of TLR4-related molecules were detected by western blotting and nuclear factor-${\kappa}B$ ($NF-{\kappa}B$) activation was measured. Our results showed that GBR extract dose-dependently inhibited mRNA expression of LPS-induced tumor necrosis factor-${\alpha}$ ($TNF-{\alpha}$), interleukin-6 (IL-6), and monocyte chemoattractant protein-1 (MCP-1). GBR extract was found to inhibit LPS-induced mRNA expression of TLR4 and protein expression of both myeloid differentiation factor 88 (MyD88) and TNF receptor-associated factor 6 (TRAF6). Furthermore, GBR extract significantly inhibited extracellular receptor-activated kinase (ERK) phosphorylation and $NF-{\kappa}B$ activation. These results suggest that GBR extract has the anti-inflammatory effects on LPS-induced inflammation via inhibition of TLR4 signaling, includingthe ERK and $NF-{\kappa}B$ signaling pathways, in adipocytes.

• International Journal of Oral Biology
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• v.38 no.3
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• pp.121-126
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• 2013

Tumor necrosis factor alpha ($TNF{\alpha}$) is a multifunctional inflammatory cytokine that regulates various cellular and biological processes. Increased levels of $TNF{\alpha}$ have been implicated in a number of human diseases including diabetes and arthritis. Sympathetic nervous system stimulation via the beta2-adrenergic receptor (${\beta}2AR$) in osteoblasts suppresses osteogenic activity. We previously reported that $TNF{\alpha}$ upregulates ${\beta}2AR$ expression in murine osteoblastic cells and that this modulation is associated with $TNF{\alpha}$ inhibition of osteoblast differentiation. In our present study, we explored whether $TNF{\alpha}$ induces ${\beta}2AR$ expression in human osteoblasts and then identified the downstream signaling pathway. Our results indicated that ${\beta}2AR$ expression was increased in Saos-2 and C2C12 cells by $TNF{\alpha}$ treatment, and that this increase was blocked by the inhibition of NF-${\kappa}B$ activation. Chromatin immunoprecipitation and luciferase reporter assay results indicated that NF-${\kappa}B$ directly binds to its cognate elements on the ${\beta}2AR$ promoter and thereby stimulates ${\beta}2AR$ expression. These findings suggest that the activation of $TNF{\alpha}$ signaling in osteoblastic cells leads to an upregulation of ${\beta}2AR$ and also that $TNF{\alpha}$ induces ${\beta}2AR$ expression in an NF-${\kappa}B$-dependent manner.

• The Korean Journal of Physiology and Pharmacology
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• v.24 no.5
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• pp.395-402
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• 2020

This study has investigated the effect of a potent bioflavonoid, troxerutin, on diabetes-induced changes in pro-inflammatory mediators and expression of microRNA-146a and nuclear factor-kappa-B (NF-κB) signaling pathway in aortic tissue of type-I diabetic rats. Male Wistar rats were randomly divided into four groups (n = 6/each): healthy, healthy-troxerutin, diabetic, and diabetic-troxerutin. Diabetes was induced by streptozotocin injection (60 mg/kg; intraperitoneally) and lasted 10 weeks. Troxerutin (150 mg/kg/day) was administered orally for last month of experiment. Inflammatory cytokines IL-1β, IL-6, and TNF-α, as well as intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule (VCAM), cyclooxygenase-II (COX-II), and inducible-nitric oxide synthase (iNOS) were measured on aortic samples by enzyme-linked immunosorbent assay. Gene expressions for transcription factor NF-κB, interleukin-1 receptor-associated kinase-1 (IRAK-1), TNF receptor-associated factor-6 (TRAF-6), and microRNA-146a were determined using real-time polymerase chain reaction. Ten-week diabetes significantly increased mRNA levels of IRAK-1, TRAF-6, NF-κB, and protein levels of cytokines IL-1β, IL-6, TNF-α, adhesion molecules ICAM-1, VCAM, and iNOS, COX-II, and decreased expression of microRNA-146a as compared with healthy rats (p < 0.05 to p < 0.01). However, one month treatment of diabetic rats with troxerutin restored glucose and insulin levels, significantly decreased expression of inflammatory genes and pro-inflammatory mediators and increased microRNA level in comparison to diabetic group (p < 0.05 to p < 0.01). In healthy rats, troxerutin had significant reducing effect only on NF-κB, TNF-α and COX-II levels (p < 0.05). Beside slight improvement of hyperglycemia, troxerutin prevented the activation of NF-κB-dependent inflammatory signaling in the aorta of diabetic rats, and this response may be regulated by microRNA-146a.