• Biomolecules & Therapeutics
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• 제31권6호
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• pp.692-699
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• 2023

The lack of molecular targets hampers the treatment of triple-negative breast cancer (TNBC). In this study, we determined the cytotoxicity of domperidone, a dopamine D2 receptor (DRD2) antagonist in human TNBC BT-549 and CAL-51 cells. Domperidone inhibited cell growth in a dose- and time-dependent manner. The annexin V/propidium iodide staining showed that domperidone induced apoptosis. The domperidone-induced apoptosis was accompanied by the generation of mitochondrial superoxide and the down-regulation of cyclins and CDKs. The apoptotic effect of domperidone on TNBC cells was prevented by pre-treatment with Mito-TEMPO, a mitochondria-specific antioxidant. The prevention of apoptosis with Mito-TEMPO even at concentrations as low as 100 nM, implies that the generation of mitochondrial ROS mediated the domperidone-induced apoptosis. Immunoblot analysis showed that domperidone-induced apoptosis occurred through the down-regulation of the phosphorylation of JAK2 and STAT3. Moreover, domperidone downregulated the levels of D2-like dopamine receptors including DRD2, regardless of their mRNA levels. Our results support further development of DRD2 antagonists as potential therapeutic strategy treating TNBC.

• The Korean Journal of Physiology and Pharmacology
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• 제15권5호
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• pp.251-258
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• 2011

Here we have investigated how lactosylceramide (LacCer) modulates gene expression of adhesion molecules in TNF-${\alpha}$ and IFN ${\gamma}$ (CM)-stimulated astrocytes. We have observed that stimulation of astrocytes with CM increased the gene expression of ICAM-1 and VCAM-1. D-Threo-1-phenyl-2-decanoylamino-3-morpholino-1-propanol (PDMP) and N-butyldeoxynojirimycin (NBDNJ), inhibitors of glucosylceramide synthase (GLS) and LacCer synthase (galactosyltransferase, GalT-2), inhibited the gene expression of ICAM-1 and VCAM-1 and activation of their gene promoter induced by CM, which were reversed by exogenously supplied LacCer. Silencing of GalT-2 gene using its antisense oligonucleotides also attenuated CM-induced ICAM-1 and VCAM-1 expression, which were reversed by LacCer. PDMP treatment and silencing of GalT-2 gene significantly reduced CM-induced luciferase activities in NF-${\kappa}B$, AP-1, GAS, and STAT-3 luciferase vectors-transfected cells. In addition, LacCer reversed the inhibition of NF-${\kappa}B$ and STAT-1 luciferase activities by PDMP. Taken together, our results suggest that LacCer may play a crucial role in the expression of ICAM-1 and VCAM-1 via modulating transcription factors, such as NF-${\kappa}B$, AP-1, STAT-1, and STAT-3 in CM-stimulated astrocytes.

• 한국수학사학회지
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• 제22권2호
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• pp.69-80
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• 2009

컴퓨터프로그래밍은 문제해결능력 향상과 논리적 사고력 함양을 위한 도구로서, 본 연구에서는 컴퓨터교육의 방향설정과 문제해결과정에서의 프로그래밍 교육의 역할을 알아보고자한다. 또한 수학/통계학과의 컴퓨터프로그래밍 특성화를 위하여 수학/통계학과와 IT학과를 연계한 프로그래밍 교과목을 분석한다. 이를 통하여 컴퓨터프로그래머로서 능력 있는 인재를 양성해서 사회에 배출하고자 한다.

• 한국식품영양과학회지
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• 제41권9호
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• pp.1226-1234
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• 2012

본 연구에서는 염증반응을 조절하는 다양한 신호전달체계를 중심으로 분자생물학적 방법을 통해 piceatannol의 항염증 기전을 규명하였다. LPS로 염증반응을 유도한 Raw 264.7 대식세포에서 piceatannol은 iNOS의 발현 억제를 통해 NO의 생성을 감소시키고 염증성 사이토카인(TNF-${\alpha}$, IL-6, IL-$1{\beta}$)의 생성을 감소시켰다. 염증반응을 조절하는 신호전달체계 중 piceatannol은 LPS에 의해 유도된 $I{\kappa}B$의 분해와 p65의 핵으로의 이동을 억제하고, LPS에 의해 유도된 SAPK/JNK의 인산화를 억제하였다. 또한 piceatannol은 LPS와 IL-6(LPS에 의해 증가됨)에 의한 STAT3의 활성화를 억제하였다. 뿐만 아니라 piceatannol은 Nrf2의 핵 내 축적을 야기하고 ARE의 transcriptional activity를 증가시켜 HO-1의 발현을 증가시켰다. 본 연구의 결과, piceatannol은 NF-${\kappa}B$와 AP-1, STAT3 신호전달의 억제를 통해, 그리고 HO-1의 발현 증가를 통해 항염증 효과를 나타내었다(Fig. 8).

• 생약학회지
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• 제44권2호
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• pp.154-160
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• 2013

Ceramium boydenii belongs to euphorbia humitusa of red algae, and is distributed along the coast of Jeju island. This study was conducted to examine the anti-inflammatory effect and action mechanism of C. boydenii in the human keratinocyte cell line HaCaT. The 80% EtOH extract of C. boydenii inhibits the production of MDC (macrophage derived chemokine), an inflammatory chemokine, induced by IFN-${\gamma}$ and TNF-${\alpha}$ in a concentration dependent manner. It also suppressed the phosphorylation and nuclear translocation of STAT1, a key transcription factor in IFN-${\gamma}$ and TNF-${\alpha}$ signaling pathway, at the effective concentrations. These results suggest that C. boydenii demonstrates the anti-inflammatory activity via the suppression of STAT1 activation and has the significant value as an anti-inflammatory source.

• Biomolecules & Therapeutics
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• 제16권4호
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• pp.394-402
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• 2008

Atopic dermatitis (AD) is an inflammatory skin disease commonly characterized by infiltration of inflammatory cells into skin lesions. Keratinocytes produce many chemokines that are involved in the pathogenesis of skin disorders. In particular, macrophage-derived chemokine (MDC/CCL22) and thymus and activationregulated chemokine (TARC/CCL17) are Th2-type cytokines. Serum MDC and TARC levels are increased in AD patients. In this study, we investigated the anti-inflammatory effect and mechanism of action of the active fraction from Prunus yedoensis bark. We evaluated their inhibitory effects on the AD-like inflammatory markers (MDC and TARC) and JAK-STAT pathway (STAT1) in HaCaT keratinocytes. The EtOAc fraction of the crude extract (80% EtOH) and the E5 sub-fraction potently inhibited the induction of MDC and TARC mRNA and protein at 50 ${\mu}g$/mL in HaCaT cells. In addition, the E5 sub-fraction inhibited the phosphorylation of STAT1 protein associated with IFN-$\gamma$ signaling transduction in a dose-dependent manner. Thus, P. yedoensis may have antiatopic activity by suppressing the inflammatory chemokines (MDC and TARC).

• Molecules and Cells
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• 제22권2호
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• pp.163-167
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• 2006

Histone deacetylase (HDAC) activity is commonly associated with transcriptional repression. However, there is also evidence for a function in transcriptional activation. Previous studies have demonstrated a fundamental role of deacetylase activity in $IFN{\alpha}$-responsive gene transcription. In the case of type II IFN ($IFN{\gamma}$) results are controversial: some genes require HDAC activity, while transcription of others is repressed by HDAC. To investigate the effect of HDAC on transcription of an $IFN{\gamma}$-activated gene, real-time PCR was used to measure CXCL10 mRNA in Hela cells stimulated with $IFN{\gamma}$ in the presence or absence of the HDAC inhibitor TSA. Chromatin imunoprecipitation combined with real-time PCR was used to check acetylation of histone H4 and recruitment of the STAT1 complex to the ISRE locus of the CXCL10 gene. Activation of CXCL10 transcription in response to $IFN{\gamma}$ was paralleled by a decrease in histone H4 acetylation and an increase in recruitment of the STAT1 complex to the CXCL10 ISRE locus. The transcription of CXCL10 and histone H4 deacetylation were blocked by TSA, but the latter had no obvious affect on recruitment of the STAT1 complex. Our data indicate that $IFN{\gamma}$ and STAT-dependent gene transcription requires the participation of HDAC, as does the $IFN{\alpha}$-STAT pathway.

• The Korean Journal of Physiology and Pharmacology
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• 제19권2호
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• pp.105-109
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• 2015

NgR1, a Nogo receptor, is involved in inhibition of neurite outgrowth and axonal regeneration and regulation of synaptic plasticity. P19 embryonal carcinoma cells were induced to differentiate into neuron-like cells using all trans-retinoic acid and the presence and/or function of cellular molecules, such as NgR1, NMDA receptors and STAT3, were examined. Neuronally differentiated P19 cells expressed the mRNA and protein of NgR1, which could stimulate the phosphorylation of STAT3 when activated by Nogo-P4 peptide, an active segment of Nogo-66. During the whole period of differentiation, mRNAs of all of the NMDA receptor subtypes tested (NR1, NR2A-2D) were consistently expressed, which meant that neuronally differentiated P19 cells maintained some characteristics of neurons, especially central nervous system neurons. Our results suggests that neuronally differentiated P19 cells expressing NgR1 may be an efficient and convenient in vitro model for studying the molecular mechanism of cellular events that involve NgR1 and its binding partners, and for screening compounds that activate or inhibit NgR1.

• Asian Pacific Journal of Cancer Prevention
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• 제15권12호
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• pp.5071-5076
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• 2014

Cholangiocarcinoma (CCA) is one of the aggressive cancers with a very poor prognosis. Several efforts have been made to identify and develop new agents for prevention and treatment of this deadly disease. In the present study, we examined the anticancer effect of luteolin on human CCA, KKU-M156 cells. Sulforhodamine B assays showed that luteolin had potent cytotoxicity on CCA cells with IC50 values of $10.5{\pm}5.0$ and $8.7{\pm}3.5{\mu}M$ at 24 and 48 h, respectively. Treatment with luteolin also caused a concentration-dependent decline in colony forming ability. Consistent with growth inhibitory effects, luteolin arrested cell cycle progression at the G2/M phase in a dose-dependent manner as assessed by flow cytometry analysis. Protein expression of cyclin A and Cdc25A was down-regulated after luteolin treatment, supporting the arrest of cells at the G2/M boundary. Besides evident G2/M arrest, luteolin induced apoptosis of KKU-M156 cells, demonstrated by a distinct sub-G1 apoptotic peak and fluorescent dye staining. A decrease in the level of anti-apoptotic Bcl-2 protein was implicated in luteolin-induced apoptosis. We further investigated the effect of luteolin on JAK/STAT3, which is an important pathway involved in the development of CCA. The results showed that interleukin-6 (IL-6)-induced JAK/STAT3 activation in KKU-M156 cells was suppressed by treatment with luteolin. Treatment with a specific JAK inhibitor, AG490, and luteolin diminished IL-6-stimulated CCA cell migration as assessed by wound healing assay. These data revealed anticancer activity of luteolin against CCA so the agent might have potential for CCA prevention and therapy.

• Asian Pacific Journal of Cancer Prevention
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• 제16권9호
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• pp.3715-3721
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• 2015

Leukemia is a clonal disorder with blocked normal differentiation and cell death of hematopoietic progenitor cells. Traditional modalities with most used radiation and chemotherapy are nonspecific and toxic which cause adverse effects on normal cells. Differentiation inducing therapy forcing malignant cells to undergo terminal differentiation has been proven to be a promising strategy. However, there is still scarce of potent differentiation inducing agents. We show here that Angelica sinensis polysaccharide (ASP), a major active component in Dong quai (Chinese Angelica sinensis), has potential differentiation inducing activity in human chronic erythro-megakaryoblastic leukemia K562 cells. MTT assays and flow cytometric analysis demonstrated that ASP inhibited K562 cell proliferation and arrested the cell cycle at the G0/G1 phase. ASP also triggered K562 cells to undergo erythroid differentiaton as revealed by morphological changes, intensive benzidine staining and hemoglobin colorimetric reaction, as well as increased expression of glycophorin A (GPA) protein. ASP induced redistribution of STAT5 protein from the cytoplasm to the nucleus. Western blotting analysis further identified that ASP markedly sensitized K562 cells to exogenous erythropoietin (EPO) by activating EPO-induced JAK2/STAT5 tyrosine phosphorylation, thus augmenting the EPO-mediated JAK2/STAT5 signaling pathway. On the basis of these findings, we propose that ASP might be developed as a potential candidate for chronic myelogenous leukemia inducing differentiation treatment.