• BMB Reports
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• 제40권2호
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• pp.290-294
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• 2007

Saxatilin is a disintegrin known to inhibit tumor progression in vivo and in vitro. The role of saxatilin in cancer cell invasion was examined by a modified Boyden chamber assay in MDAH 2774 human ovarian cancer cell line. Saxatilin (50 nM) significantly inhibited cancer cell invasion induced by tumor necrosis factor-$\alpha$ (TNF-a$\alpha$). Saxatilin also reduced MMP-9 mRNA levels in cancer cells in a dosedependent manner. In addition, TNF-$\alpha$-induced MMP-9 activity was reduced by the treatment of saxatilin. These results indicate that transcriptional regulation of MMP-9 is an important mechanism for the tumor suppressive effects of saxatilin in MDAH 2774 human ovarian cancer cells.

• Tuberculosis and Respiratory Diseases
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• 제42권3호
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• pp.302-313
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• 1995

연구배경: 종양괴사인자(Tumor necrosis factor; TNF)는 다양한 생물학적인 작용을 가지며 종양 세포에 대한 세포 독성은 그 대표적인 기능중의 하나이다. TNF-$\alpha$는 생체외에서(in vitro) 몇몇 종양 세포주에 대하여 항암제, 특히 topoisomerase II targeted chemotherapeutic agent의 세포 독성 효과를 상승적으로 증가시키는 것이 알려져 있다. 최근 암세포에 대한 cytokine 유전자 요법에서 TNF는 중요한 대상으로 여겨지고 있으며, 유전자 이입에 의해 암조직이 TNF를 생성하게 될 경우 암 증식 억제 효과가 있음이 보고되고 있다. 연구자는 암세포에 TNF-$\alpha$ 유전자를 이입하여 자신이 TNF-$\alpha$를 생성하도록 형질을 변환시킨 암세포는 topoisomerase II 억제 항암제에 대한 김수성에 변화가 있을 것이라는 가설을 수립하였고 이를 검증하고자 본 연구를 수행하였다. 본 연구에서는 생체외로(in vitro) TNF-$\alpha$ 유전자를 이입하여 TNF-$\alpha$를 생성하는 암세포주에서 topoisomerase II targeted drug에 대한 항암제 감수성 효과가 모세포주에 비하여 증대될 수 있는지를 알아 보고자하였다. 방법: TNF-$\alpha$에 감수성을 보이는 것으로 알려진 인체 중피종 세포주인 NCI-H2058 세포주 및 생쥐의 섬유육종 세포주인 WEHI164 세포주와 인체 비소세포 폐암 세포주인 A549 세포주를 배양하여, 먼저 임상에서 흔히 폐암의 항암 화학 요법 치료에 널리 쓰이는 대표적인 topoisomerase II targeted chemotherapeutic drug인 etoposide(VP-16)와 doxorubicin(adriamycin)을 가하였을 때 관찰된 세포 독성을 MTT assay로 측정하고, 각 모세포주(parenta1 cell line)에 TNF-$\alpha$의 유전자를 이입시켜서 형절 변환한 세포주(transformed cell line)에 대하여 각각 동일한 항암제를 가하였을 때 관찰된 세포 독성의 정도를 같은 방법으로 측정하여, 그 결과를 비교 분석하였다. 또한 모세포주에 외부에서 TNF를 가하여 전처치한 후 동일한 항암제를 가하였을 때의 세포독성을 관찰하여 비교 분석하였다. 결과: H2058 세포주에서는 TNF-$\alpha$ 유전자를 이입한 세포주 topoisomerase II targeted drug을 가하였을 때, 항암제 감수성이 모세포주에 같은 항암제를 가하였을 때에 비하여 의미있게 증가함을 관찰할 수 있었으나(p<0.05), WEHI 세포주와 A549 세포주에 있어서는 TNF-$\alpha$ 유전자를 이입한 세포주에서 모세포주에 비하여 항암제 감수성이 증가하지는 않았다. 결론: TNF-$\alpha$ 유전자의 이입이 topoisomerase II targeted chemotherapeutic drug에 대한 항암제 감수성을 증가시키는 효과는 세포주에 따라 다양한 결과를 보이는 것을 알 수 있었으며, 적어도 선택된 특정 종류의 호흡기계 암세포에 있어서는 TNF-$\alpha$ 유전자의 이입으로 항암제 감수성(chemosensitivity)을 증가시킬 수 있을 것으로 사료된다.

• 생명과학회지
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• 제22권5호
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• pp.697-701
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• 2012

본 연구에서는 항응고제로서의 역할을 가지면서 또한 혈액응고와는 관련 없는 종양세포의 전이 등을 조절하는 것으로 알려진 activated protein C (APC)가 종양세포의 사멸에는 어떠한 영향을 미치는 지에 대한 연구를 수행하였다. Tumor necrosis factor (TNF)-${\alpha}$와 cyclohexamide를 병합 처리하거나 FAS를 처리하게 되면 인간 신장암세포인 Caki에서는 유의적인 세포사멸이 일어난다. 하지만, APC는 이러한 세포사멸에 아무런 영향을 미치지 못하였다. 또한 TRAIL을 인간 뇌 암세포인 T98G와 유방암세포인 MDA231세포에 처리하여 세포사멸을 일으켰을 때에도 APC는 세포사멸을 조절하지 못하였다. 그러나, TRAIL에 대한 민감도를 증가시키기 위한 kahweol과 TRAIL의 병합처리나, kahweol과 malatonin의 병합처리에 의한 신장암세포의 사멸은 APC에 의해 유의적으로 억제되는 것을 확인하였다. 따라서, 이는 APC가 항암치료의 효율성을 조절 할 수 있는 가능성을 가짐을 의미한다.

• The Korean Journal of Physiology and Pharmacology
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• 제16권2호
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• pp.131-138
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• 2012

Alcoholic hepatitis is a leading cause of liver failure in which the increased production of tumor necrosis factor ${\alpha}$ (TNF${\alpha}$) plays a critical role in progression of alcoholic liver disease. In the present study, we investigated the effects of cilostazol, a selective inhibitor of type III phosphodiesterase on ethanol-mediated TNF${\alpha}$ production in vitro and $in$ $vivo$, and the effect of cilostazol was compared with that of pentoxifylline, which is currently used in clinical trial. RAW264.7 murine macrophages were pretreated with ethanol in the presence or absence of cilostazol then, stimulated with lipopolysacchride (LPS). Cilostazol significantly suppressed the level of LPS-stimulated TNF${\alpha}$ mRNA and protein with a similar degree to that by pentoxifylline. Cilostazol increased the basal AMP- activated protein kinase (AMPK) activity as well as normalized the decreased AMPK by LPS. AICAR, an AMPK activator and db-cAMP also significantly decreased TNF${\alpha}$ production in RAW264.7 cells, but cilostazol did not affect the levels of intracellular cAMP and reactive oxygen species (ROS) production. The $in$ $vivo$ effect of cilostazol was examined using ethanol binge drinking (6 g/kg) mice model. TNF${\alpha}$ mRNA and protein decreased in liver from ethanol gavaged mice compared to that from control mice. Pretreatment of mice with cilostazol or pentoxifylline further reduced the TNF${\alpha}$ production in liver. These results demonstrated that cilostazol effectively decrease the ethanol-mediated TNF${\alpha}$ production both in murine macrophage and in liver from binge drinking mice and AMPK may be responsible for the inhibition of TNF${\alpha}$ production by cilostazol.

• International Journal of Oral Biology
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• 제38권3호
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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.

• Journal of Periodontal and Implant Science
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• 제48권5호
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• pp.284-294
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• 2018

Purpose: Epithelial barrier dysfunction is involved in the pathophysiology of periodontitis and oral lichen planus. Estrogens have been shown to enhance the physical barrier function of intestinal and esophageal epithelia, and we aimed to investigate the effect of estradiol (E2) on the regulation of physical barrier and tight junction (TJ) proteins in human oral epithelial cell monolayers. Methods: HOK-16B cell monolayers cultured on transwells were treated with E2, an estrogen receptor (ER) antagonist (ICI 182,780), tumor necrosis factor alpha ($TNF{\alpha}$), or dexamethasone (Dexa), and the transepithelial electrical resistance (TER) was then measured. Cell proliferation was measured by the cell counting kit (CCK)-8 assay. The levels of TJ proteins and nuclear translocation of nuclear factor $(NF)-{\kappa}B$ were examined by confocal microscopy. Results: E2 treatment increased the TER and the levels of junctional adhesion molecule (JAM)-A and zonula occludens (ZO)-1 in a dose-dependent manner, without affecting cell proliferation during barrier formation. Treatment of the tight-junctioned cell monolayers with $TNF{\alpha}$ induced decreases in the TER and the levels of ZO-1 and nuclear translocation of $NF-{\kappa}B$. These $TNF{\alpha}-induced$ changes were inhibited by E2, and this effect was completely reversed by co-treatment with ICI 182,780. Furthermore, E2 and Dexa presented an additive effect on the epithelial barrier function. Conclusions: E2 reinforces the physical barrier of oral epithelial cells through the nuclear ER-dependent upregulation of TJ proteins. The protective effect of E2 on the $TNF{\alpha}-induced$ impairment of the epithelial barrier and its additive effect with Dexa suggest its potential use to treat oral inflammatory diseases involving epithelial barrier dysfunction.

• The Korean Journal of Physiology and Pharmacology
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• 제15권3호
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• pp.157-162
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• 2011

Vascular inflammation process has been suggested to be an important risk factor in the development of atherosclerosis. Recently we reported that induction of peroxisome proliferator-activated receptor-${\gamma}$ (PPAR-${\gamma}$) selectively inhibits vascular cell adhesion molecule-1 (VCAM-1) but not intercellular cell adhesion molecule-1 (ICAM-1) in tumor necrosis factor (TNF)-${\alpha}$-activated human umbilical vein endothelial cells (HUVEC). In this study, we investigated whether genipin inhibits expression of cellular adhesion molecules, which is relevant to inflammation. Pretreatment with genipin reduced reactive oxygen species (ROS) production and expression of VCAM-1, but not ICAM-1 in TNF-${\alpha}$-activated HUVEC. Genipin dose- and time-dependently increased PPAR-${\gamma}$ expression and inhibited TNF-${\alpha}$-induced phosphorylation of Akt and PKC with different degrees. Finally, genipin prevented TNF-${\alpha}$-induced adhesion of U937 monocytic cells to HUVEC. Taken together, these results indicate that upregualtion of PPAR-${\gamma}$ by genipin selectively inhibits TNF-${\alpha}$-induced expression of VCAM-1, in which regulation of Akt and/or PKC play a key role. We concluded that genipin can be used for the treatment of cardiovascular disorders such as atherosclerosis.

• 생명과학회지
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• 제23권6호
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• pp.825-831
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• 2013

본 연구를 통하여 streptozotocin 주사에 의한 당뇨 유발이 일반식이와 고지방식이로 키운 C57BL/6 수컷생쥐의 지방조직에서의 염증성 사이토카인 유전자 발현에 미치는 영향을 조사하였다. 네 그룹의 당뇨생쥐(일반식이 또는 고지방식이로 키운 16주령 또는 26주령 생쥐)와 네 그룹의 비당뇨 대조군을 포함한 모두 73마리의 생쥐가 이 실험에 사용되었다. Real-time PCR을 이용하여 지방조직에서의 tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$)와 monocyte chemoattractant protein-1 (MCP-1)의 유전자 발현량을 측정한 결과, TNF-${\alpha}$ mRNA는 당뇨 유발에 의해 증가하는 양상을 보였다. 특히, 16주령의 일반식이 생쥐의 경우 비당뇨 대조군에 비해 당뇨가 유발된 실험군에서 유의한 증가가 관찰되었다. MCP-1 mRNA 발현은 STZ처리에 따른 당뇨유발에 의해 감소하는 경향을 나타내었다. 특히, 16주령 고지방식이의 당뇨 실험군에서의 발현이 비당뇨 대조군에서의 발현량의 26%에 해당할 정도로 큰 감소를 나타내었다. 또한, MCP-1의 발현은 인슐린 농도와 유의한 상관관계가 있음이 확인되었다. 이들 실험결과는 당뇨 모델 생쥐에서 지방조직의 염증성 사이토카인이 이상발현되고 있음을 나타내며, 비만, 인슐린저항성, 및 당뇨에서의 저준위 염증상태와 지방조직에서의 염증성 사이토카인 발현 조절의 기작을 밝히는데 유용한 정보를 제공할 것으로 기대된다.

• Asian Pacific Journal of Cancer Prevention
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• 제14권5호
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• pp.3275-3279
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• 2013

Background: Tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$) plays a very important role in the development and progression of cancer. Many epidemiological studies have evaluated associations between the TNF-${\alpha}$ 238 G/A polymorphism and hepatocellular carcinoma (HCC) risk, but the published data are inconclusive. Therefore, we performed the present meta-analysis. Methods: Electronic searches of several databases were conducted for all publications on the association between TNF-${\alpha}$ 238 G/A polymorphism and HCC through July 2012. Asummary odds ratio (OR) with its 95% confidence interval (CI) were calculated to evaluate the strength of this association. Results: Eleven case-control studies with a total of 1,572 HCC cases and 1,875 controls were finally included in this meta-analysis. Overall, the TNF-${\alpha}$ 238 G/A polymorphism was significantly associated with increased risk of hepatocellular carcinoma in three genetic comparison models (For A versus G: OR 1.32, 95%CI 1.04-1.69, P = 0.02, $I_2$ = 40%; for AG versus GG: OR 1.32, 95%CI 1.02-1.71, P = 0.03, $I_2$ = 40%; for AA/AG versus GG: OR 1.33, 95%CI 1.03-1.72, P = 0.03, $I_2$ = 41%) when all studies were pooled. Subgroup analysis by ethnicity further showed that there was a significant association between the TNF-${\alpha}$ 238 G/A polymorphism and risk of HCC in Asians under three genetic comparison models (For A versus G: OR 1.30, 95%CI 1.00-1.68, P = 0.05, $I_2$ = 45% for AA/AG versus GG: OR 1.31, 95%CI 1.00-1.71, P = 0.05, $I_2$ = 46%). Conclusions: This meta-analysis provided convincing evidence that the TNF-${\alpha}$ 238 G/A polymorphism is associated with increased susceptibility to HCC. However, more well-designed studies with large sample size are needed to validate this association in Caucasians.

• The Korean Journal of Pain
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• 제24권4호
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• pp.185-190
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• 2011

Background: Spinal nerve ligation (SNL) injury in rats produces a pain syndrome that includes mechanical and thermal allodynia. Previous studies have indicated that proinflammatory cytokines such as tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$) play an important role in peripheral mediation of neuropathic pain, and that altered dorsal root ganglion (DRG) function and degree of DRG neuronal apoptosis are associated with spinal nerve injury. The present study was conducted to evaluate the expression of TNF-${\alpha}$ and the extent of apoptosis in the dorsal root ganglion after SNL in rats. Methods: Sprague-Dawley rats were subjected to SNL of the left L5 and L6 spinal nerves distal to the DRG and proximal to the formation of the sciatic nerve. At postoperative day 8, TNF-${\alpha}$ protein levels in the L5.6 DRG were compared between SNL and naive groups using ELISA. In addition, we compared the percentage of neurons injured in the DRG using immunostaining for apoptosis and localization of activated caspase-3. Results: SNL injury produced significant mechanical and cold allodynia throughout the 7-day experimental period. TNF-${\alpha}$ protein levels were increased in the DRG in rats that had undergone SNL ($12.7{\pm}3.2$ pg/100 ${\mu}g$, P < 0.001) when compared with naive rats ($4.1{\pm}1.4$ pg/100 ${\mu}g$). The percentage of neurons or satellite cells co-localized with activated caspase-3 were also significantly higher in rats with SNL than in naive rats (P < 0.001, P < 0.05, respectively). Conclusions: SNL injury produces mechanical and cold allodynia, as well as TNF-${\alpha}$ elevation and apoptosis in the DRG.