• Biomolecules & Therapeutics
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• 제17권3호
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• pp.219-240
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• 2009

Since NF-${\kappa}B$ has been identified as a transcription factor associated with immune cell activation, groups of researchers have dedicated to reveal detailed mechanisms of nuclear factor of ${\kappa}B$ (NF-${\kappa}B$) in inflammatory signaling for decades. The various molecular components of NF-${\kappa}B$ transcription factor pathway have been being evaluated as important therapeutic targets due to their roles in diverse human diseases including inflammation, cystic fibrosis, sepsis, rheumatoid arthritis, cancer, atherosclerosis, ischemic injury, myocardial infarction, osteoporosis, transplantation rejection, and neurodegeneration. With regards to new drugs directly or indirectly modulating the NF-${\kappa}B$ pathway, FDA recently approved a proteasome inhibitor bortezomib for the treatment of multiple myeloma. Many pharmaceutical companies have been trying to develop new drugs to inhibit various kinases in the NF-${\kappa}B$ signaling pathway for many therapeutic applications. However, a gene knock-out study for $IKK{\beta}$ in the NF-${\kappa}B$ pathway has given rise to controversies associated with efficacy as therapeutics. Mice lacking hepatocyte $IKK{\beta}$ accelerated cancer instead of preventing progress of cancer. However, it is clear that pharmacological inhibition of $IKK{\beta}$ appears to be beneficial to reduce HCC. This article will update issues of the NF-${\kappa}B$ pathway and inhibitors regulating this pathway.

• Journal of Microbiology and Biotechnology
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• 제16권3호
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• pp.391-398
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• 2006

$NF-{\kappa}B$ is a transcription factor involved in the innate immunity against bacterial infection and inflammation. It is also known to render cells resistant to the apoptosis caused by some anticancer drugs. Such a chemoresistance of cancer cells may be related to the activation of $NF-{\kappa}B$ transcription factor; however, the mechanism of activation is not well understood. Here, we demonstrate that a chemotherapeutic agent, etoposide, independently stimulates the $I{\kappa}B{\alpha}$ degradation pathway and PI3-kinase/Akt signaling pathway: The classical $I{\kappa}B{\alpha}$ degradation pathway leads to the nuclear translocation and DNA binding of p65 subunit through $IKK{\beta}$ kinase, whereas the PI3-kinase/Akt pathway plays a distinct role in activating this transcription factor. The PI3-kinase/Akt pathway acts on the p50 subunit of the $NF-{\kappa}B$ transcription factor and enhances the DNA binding affinity of the p50 protein. It may also explain the role of the PI3-kinase/Akt pathway in the anti-apoptotic function of $NF-{\kappa}B$ during chemoresistance of cancer cells.

• Molecules and Cells
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• 제37권3호
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• pp.189-195
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• 2014

The NF-${\kappa}B$ pathway transcriptionally controls a large set of target genes that play important roles in cell survival, inflammation, and immune responses. While many studies showed anti-tumorigenic and pro-survival role of NF-${\kappa}B$ in cancer cells, recent findings postulate that NF-${\kappa}B$ participates in a senescence-associated cytokine response, thereby suggesting a tumor restraining role of NF-${\kappa}B$. In this review, we discuss implications of the NF-${\kappa}B$ signaling pathway in cancer. Particularly, we emphasize the connection of NF-${\kappa}B$ with cellular senescence as a response to chemotherapy, and furthermore, present examples how distinct oncogenic network contexts surrounding NF-${\kappa}B$ produce fundamentally different treatment outcomes in aggressive B-cell lymphomas as an example.

• Tuberculosis and Respiratory Diseases
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• 제49권3호
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• pp.332-342
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• 2000

연구배경 : 염증매개 사이토카인은 염증성 폐질환의 중요한 매개물질이다. 폐 상피세포는 염증세포에서 분비되는 사이토카인에 의해 interleukin, chemokines, colony stimulating factors와 growth factor등을 생산 및 분비함으로써 국소 염증 부위에서의 사이토카인 network에 중요한 역할을 한다. 따라서 폐 상피세포에서 염증매개 사이토카인의 발현 기전에 대한 이해는 염증성 폐질환의 기전규명과 이에 기초한 새로운 치료법의 개발에 생각된다. 대부분의 사이토카인은 NF-${\kappa}B$전사인자에 의해 발현되는데 폐 상피세포에서 염증매개 사이토키인의 발현과 NF-${\kappa}B/I{\kappa}B$ 경로와의 관련성에 관한 연구는 부족한 실정이다. 방법 : BEAS-2B, A549, NCI-H157, NCI-H719 세포에서 IL-1$\beta$와 TNF-$\alpha$ 자극에 의한 IL-8과 TNF-$\alpha$ mRNA의 발현 양상을 평가하였고 이들의 발현과 관찰하였고 NF-${\kappa}B/I{\kappa}B$ 경로와의 관련성을 평가하기 위하여 IL-l$\beta$와 TNF-$\alpha$ 자극에 의한 NF-${\kappa}B$의 활성화 및 $I{\kappa}B{\alpha}$와 $I{\kappa}B{\beta}$의 분해 양상을 관찰하였다. 폐 상피세포의 종류에 따른 NF-${\kappa}B/I{\kappa}B$ 경로 조절의 기전을 규명하고자 IL-1$\beta$와 TNF-$\alpha$ 자극에 의한 $I{\kappa}B{\alpha}$의 인산화와 기저상태에서 IKK$\alpha$의 발현을 평가하였다. 결과 : BEAS-2B, A549, NCI-H157 세포에서는 IL-1$\beta$와 TNF-$\alpha$ 자극으로 $I{\kappa}B{\alpha}$와 $I{\kappa}B{\beta}$가 분해되었고 NF-${\kappa}B$의 활성화가 관찰되었으며 IL-8과 TNF-$\alpha$mRNA의 발현이 유도되었다. NCI-H719 세포에서는 IL-1$\beta$와 TNF-$\alpha$ 자극으로 $I{\kappa}B$ 분해에 의한 NF-${\kappa}B$의 활성화 및 염증매개 사이토카인의 발현이 관찰되지 않았다. BEAS-2B, A549, NCI-H157 세포에서는 IL-1$\beta$와 TNF-$\alpha$ 자극으로 ${\kappa}B$의 인산화가 관찰되었지만 NCI-H719 세포에서는 관찰되지 않았다. 기저상태의 IKK$\alpha$ 발현은 세포간에 차이가 관찰되지 않았다. 결론 : 폐 상피세포에서 NF-${\kappa}B/I{\kappa}B$ 경로는 염증매개 사이토카인 발현에 매우 중요한 역할을 하고, 일부 세포에서는 NF-${\kappa}B/I{\kappa}B$ 경로 조절의 차이를 보이는데 이는 IKK보다 상위 단계의 세포내 신호전달체계의 이상에 기인한 것으로 생각된다.

• Molecules and Cells
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• 제20권2호
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• pp.241-246
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• 2005

PDK-1 activates PI3-kinase/Akt signaling and regulates fundamental cellular functions, such as growth and survival. NF-${\kappa}B$ is involved in the induction of a variety of cellular genes affecting immunity, inflammation and the resistance to apoptosis induced by some anti-cancer drugs. Even though the crucial involvement of the PI3-kinase/Akt pathway in the anti-apoptotic activation of NF-${\kappa}B$ is well known, the exact role of PDK-1 as well as PI3-kinase/Akt in NF-vactivation is not understood. Here we demonstrate that PDK-1 plays a pivotal role in transcriptional activation of NF-${\kappa}B$ by dissociating the transcriptional co-repressor HDAC1 from the p65 subunit of NF-${\kappa}B$. The association of CBP with p65 was not directly modulated by PDK-1 or by PI3-kinase. Etoposide activated NF-${\kappa}B$ through PI3-kinase/Akt, and the transcription activation domain (TAD) of p65 was further activated by wild-type PDK-1. Overexpression of a dominant negative PDK-1 mutant decreased etoposide-induced NF-${\kappa}B$ transcription and further down-regulated the ectopic HDAC1-mediated decrease in NF-${\kappa}B$ transcriptional activity. Thus activation of PDK-1 relieves the HDAC1-mediated repression of NF-${\kappa}B$ that may be related to basal as well as activated transcription by NF-${\kappa}B$. This effect may also explain the role of the PI3-kinase/PDK-1 pathway in the anti-apoptotic function of NF-${\kappa}B$ associated with the chemoresistance of cancer cells.

• Tuberculosis and Respiratory Diseases
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• 제54권5호
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• pp.551-562
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• 2003

연구배경 : NF-${\kappa}B$는 많은 염증 유발성 물질들을 발현시키는데 필요한 전사 인자로서, 염증성 폐질환 발병에 관여한다는 사실이 확인되었다. 이러한 NF-${\kappa}B$의 활성화에는 여러 신호전달 체계가 관여한다는 사실이 밝혀지고 있으며 최근 PI3K/Akt 경로도 NF-${\kappa}B$ 활성화에 관여한다는 연구 결과가 보고되고 있으나, 실험 대상 세포주마다 활성화 기전이 다르고 호흡기 상피세포에 대한 결과도 알려져 있지 않아 호흡기 상피세포에서의 NF-${\kappa}B$ 활성화에 PI3K/Akt 경로가 관여하는지를 밝히기 위하여 본 연구를 시행하게 되었다. 방법 : 인체 기관지 상피세포주인 BEAS-2B와 폐암 세포주인 A549, NCI-H157을 사용하여 Akt 활성화와 $I{\kappa}B{\alpha}$ 분해 여부를 확인하기 위해 western blot을 시행하였다. Wortmannin, LY294002 및 DN-Akt를 이용하여 Akt 경로를 억제하였고, NF-${\kappa}B$ 활성화와 전사 활성을 측정하기 위하여 각각 EMSA와 luciferase assay를 시행하였다. 결과 : BEAS-2B, A549 및 NCI-H157 세포주에 TNF-$\alpha$ 및 insulin을 처리한 경우 Akt 활성화가 유도되었다. Insulin 으로 Akt 경로를 활성화시킨 경우 $I{\kappa}B{\alpha}$ 분해가 일어나지는 않았다. Wortmannin, LY294002 및 DN-Akt 를 이용하여 Akt 경로를 억제한 경우 TNF-$\alpha$에 의한 $I{\kappa}B{\alpha}$ 분해 및 IKK 활성화가 억제되지는 않았으며, NF-${\kappa}B$ 활성화도 억제되지 않았다. Wortmannin을 처리한 경우 TNF-$\alpha$에 의한 NF-${\kappa}B$ 전사 활성이 오히려 증가하는 양상을 보였으나, DN-Akt 이입시킨 경우에는 관찰되지 않았다. 결론 : 인체 호흡기 상피세포에서는 $I{\kappa}B$/NF-${\kappa}B$ 경로의 활성화는 PI3K/Akt 경로와 무관한 것으로 판단된다.

• Molecules and Cells
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• 제28권1호
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• pp.49-55
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• 2009

Hepatitis delta virus (HDV) infection causes fulminant hepatitis and liver cirrhosis. To elucidate the molecular mechanism of HDV pathogenesis, we examined the effects of HDV viral proteins, the small hepatitis delta antigen (SHDAg) and the large hepatitis delta antigen (LHDAg), on $NF-{\kappa}B$ signaling pathway. In this study, we demonstrated that $TNF-{\alpha}-induced$ $NF-{\kappa}B$ transcriptional activation was increased by LHDAg but not by SHDAg in both HEK293 and Huh7 cells. Furthermore, LHDAg promoted TRAF2-induced $NF-{\kappa}B$ activation. Using coimmunoprecipitation assays, we demonstrated that both SHDAg and LHDAg interacted with TRAF2 protein. We showed that isoprenylation of LHDAg was not required for the increase of $NF-{\kappa}B$ activity. We further showed that only LHDAg but not SHDAg increased the $TNF-{\alpha}-mediated$ nuclear translocation of p65. This was accomplished by activation of $I{\kappa}B_{\alpha}$ degradation by LHDAg. Finally, we demonstrated that LHDAg augmented the COX-2 expression level in Huh7 cells. These data suggest that LHDAg modulates $NF-{\kappa}B$ signaling pathway and may contribute to HDV pathogenesis.

• The Korean Journal of Physiology and Pharmacology
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• 제19권3호
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• pp.211-218
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• 2015

The present study showed that silymarin, a polyphenolic flavonoid isolated from milk thistle (Silybum marianum), inhibited lipopolysaccharide (LPS)-induced morphological changes in the mouse RAW264.7 macrophage cell line. We also showed that silymarin inhibited the nuclear translocation and transactivation activities of nuclear factor-kappa B (NF-${\kappa}B$), which is important for macrophage activation-associated changes in cell morphology and gene expression of inflammatory cytokines. BAY-11-7085, an NF-${\kappa}B$ inhibitor, abrogated LPS-induced morphological changes and NO production, similar to silymarin. Treatment of RAW264.7 cells with silymarin also inhibited LPS-stimulated activation of mitogen-activated protein kinases (MAPKs). Collectively, these experiments demonstrated that silymarin inhibited LPS-induced morphological changes in the RAW264.7 mouse macrophage cell line. Our findings indicated that the most likely mechanism underlying this biological effect involved inhibition of the MAPK pathway and NF-${\kappa}B$ activity. Inhibition of these activities by silymarin is a potentially useful strategy for the treatment of inflammation because of the critical roles played by MAPK and NF-${\kappa}B$ in mediating inflammatory responses in macrophages.

• Asian Pacific Journal of Cancer Prevention
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• 제15권22호
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• pp.9835-9839
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• 2014

Fisetin is an effective compound extracted from lacquer which has been used in the treatment of various diseases. Preliminary data indicate that it also exerts specific anti-cancer effects. However, the manner in which fisetin regulates cancer growth remains unknown. In this study, we elucidated interference of fisetin with targets of the nuclear factor ${\kappa}B$ signal transduction pathway activated by Epstein-Barr virus encoding latent membrane protein 1 (LMP1)in nasopharyngeal carcinoma (NPC) cells, Results showed that fisetin inhibited the survival rate of CNE-LMP1 cells and NF-${\kappa}B$ activation caused by LMP1. Fisetin also suppressed nuclear translocation of NF-${\kappa}B$ (p65) and $I{\kappa}B{\alpha}$ phosphorylation, while inhibiting CyclinD1, all key targets of the NF-${\kappa}B$ signal transduction pathway. It was suggested that interference effects of fisetin with signal transduction activated by LMP1 encoded by the Epstein-Barr virus may play an important role in its anticancer potential.

• Biomolecules & Therapeutics
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• 제23권1호
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• pp.39-44
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• 2015

Tolfenamic acid (TA) is a traditional non-steroid anti-inflammatory drug (NSAID) and has been broadly used for the treatment of migraines. Nuclear factor kappa B (NF-${\kappa}B$) is a sequence-specific transcription factor and plays a key role in the development and progression of inflammation and cancer. We performed the current study to investigate the underlying mechanisms by which TA suppresses inflammation focusing on NF-${\kappa}B$ pathway in TNF-${\alpha}$ stimulated human normal and cancer cell lines and lipopolysaccharide (LPS)-stimulated mouse macrophages. Different types of human cells (HCT116, HT-29 and HEK293) and mouse macrophages (RAW264.7) were pre-treated with different concentrations of TA and then exposed to inflammatory stimuli such as TNF-${\alpha}$ and LPS. Transcriptional activity of NF-${\kappa}B$, $l{\kappa}B-{\alpha}$-degradation, p65 translocation and mitogen-activated protein kinase (MAPK) activations were measured using luciferase assay and Western blots. Pre-treatment of TA repressed TNF-${\alpha}$- or LPS-stimulated NF-${\kappa}B$ transactivation in a dose-dependent manner. TA treatment reduced degradation of $l{\kappa}B-{\alpha}$ and subsequent translocation of p65 into nucleus. TA significantly down-regulated the phosphorylation of c-Jun N-terminal kinase (JNK). However, TA had no effect on NF-${\kappa}B$ signaling and JNK phosphorylation in HT-29 human colorectal cancer cells. TA possesses anti-inflammatory activities through suppression of JNK/NF-${\kappa}B$ pathway in different types of cells.