• Title/Summary/Keyword: HT29 cells

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Assessment of Lipopolysaccharide-binding Activity of Bifidobacterium and Its Relationship with Cell Surface Hydrophobicity, Autoaggregation, and Inhibition of Interleukin-8 Production

  • Park, Myeong-Soo;Kim, Min-Jeong;Ji, Geun-Eog
    • Journal of Microbiology and Biotechnology
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    • v.17 no.7
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    • pp.1120-1126
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    • 2007
  • This study was performed to screen probiotic bifidobacteria for their ability to bind and neutralize lipopolysaccharides (LPS) from Escherichia coli and to verify the relationship between LPS-binding ability, cell surface hydrophobicity (CSH), and inhibition of LPS-induced interleukin-8 (IL-8) secretion by HT-29 cells of the various bifidobacterial strains. Ninety bifidobacteria isolates from human feces were assessed for their ability to bind fluorescein isothiocyanate (FITC)-labeled LPS from E. coli. Isolates showing 30-60% binding were designated LPS-high binding (LPS-H) and those with less than 15% binding were designated LPS-low binding (LPS-L). The CSH, autoaggregation (AA), and inhibition of LPS-induced IL-8 release from HT-29 cells of the LPS-H and LPS-L groups were evaluated. Five bifidobacteria strains showed high levels of LPS binding, CSH, AA, and inhibition of IL-8 release. However, statistically significant correlations between LPS binding, CSH, AA, and reduction of IL-8 release were not found. Although we could isolate bifidobacteria with high LPS-binding ability, CSH, AA, and inhibition of IL-8 release, each characteristic should be considered as strain dependent. Bifidobacteria with high LPS binding and inhibition of IL-8 release may be good agents for preventing inflammation by neutralizing Gram-negative endotoxins and improving intestinal health.

EGFR Antisense Oligonucleotides Encapsulated with Nanoparticles Decrease EGFR, MAPK1 and STAT5 Expression in a Human Colon Cancer Cell Line

  • Najar, Ahmad Gholamhoseinian;Pashaei-Asl, Roghiyeh;Omidi, Yadollah;Farajnia, Safar;Nourazarian, Ali Reza
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.1
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    • pp.495-498
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    • 2013
  • Epidermal growth factor receptor (EGFR) is over-expressed in several human cancers. This would suggest that inhibition of EGFR is a reasonable approach for cancer treatment. In this study we investigated EGFR blocking and its effects on the mediated signaling such as MAPK and STATb in HT29 cells. For this aim we used FITC-labeled EGFR antisense oligonucleotides encapsulated with PAMAM nanoparticles to inhibit EGFR expression. Cellular uptake of antisense was investigated by fluorescence microscopy and flow cytometry analysis. The effect of EGFR antisense on the expression of EGFR in HT29 cells was examined by real time PCR and Western blots, which showed that antisense encapsulated with PAMAM decreased the level of EGFR mRNA and protein. In addition, real time PCR results confirmed that EGFR inhibition had an effective role in the reduction of EGFR dependent downstream genes. In conclusion, EGFR antisense encapsulated with PAMAM nanoparticles down regulated EGFR and EGFR-mediated genes.

Effects of a Multikinase Inhibitor Motesanib (AMG 706) Alone and Combined with the Selective DuP-697 COX-2 Inhibitor on Colorectal Cancer Cells

  • Kaya, Tijen Temiz;Altun, Ahmet;Turgut, Nergiz Hacer;Ataseven, Hilmi;Koyluoglu, Gokhan
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.3
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    • pp.1103-1110
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    • 2016
  • In the present study, we investigated the effects of motesanib (AMG 706), a multikinase inhibitor alone and in combination with DuP-697, an irreversible selective inhibitor of COX-2, on cell proliferation, angiogenesis, and apoptosis induction in a human colorectal cancer cell line (HT29). Real time cell analysis (RTCA, Xcelligence system) was used to determine the effects on colorectal cancer cell proliferation. Apoptosis was assessed with annexin V staining and angiogenesis was determined with chorioallantoic membrane model. We found that motesanib alone exerted antiproliferative, antiangiogenic and apoptotic effects on HT29 colorectal cancer cells. Combination with DUP-697 increased the antiproliferative, antiangiogenic and apoptotic effects. Results of this study indicate that motesanib may be a good choice in treatment of colorectal tumors. In addition, the increased effects of combination of motesanib with DuP-697 raise the possibility of using lower doses of these drugs and therefore avoid/minimize the dose-dependent side effects generally observed.

Effect of Prunella vulgaris L. on Chemopreventive Enzymes of Colorectal Cancer (꿀풀하고초가 직장암 예방효소 활성에 미치는 영향)

  • Shon, Yun-Hee;Seo, Jae-Beom;Nam, Kyung-Soo
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.22 no.1
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    • pp.126-130
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    • 2008
  • Water extract from Prunella vulgaris L. (PVW) was tested for colon cancer chemopreventive activity by measuring the activities of cytochrome P450 1A1, phase Ⅱ detoxification enzyme [quinone reductase (QR) and glutathione S-transferase (GST)] and ornithine decarboxylase (ODC) and glutathione (GSH) levels in cultured human colorectal adenocarcinoma HT-29 cells. PVW significantly inhibited 7,12-dimethylbenz[a]anthracene (DMBA)-induced cytochrome P450 1A1 activity at 10 and 50 ${\mu}g/ml$. PVW induced QR activity in a dose-dependent manner over a concentration range of $1{\sim}50\;{\mu}g/ml$. GST activity was also induced with the treatment of PVW in HT-29 cells. In addition GSH levels were increased with PVW. PVW inhibited ODC activity, a key enzyme of polyamine biosynthesis, which is enhanced in tumor promotion. These results suggest that Prunella vulgaris L. has colon cancer chemopreventive activity by inhibiting cytochrome P450 1A1 and ODC activities and by increasing phase Ⅱ enzyme activity and GSH levels.

Ginseng and ion channels: Are ginsenosides, active component of Panax ginseng, differential modulator of ion channels?

  • Jeong, Sang-Min;Nah, Seung-Yeol
    • Journal of Ginseng Research
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    • v.29 no.1
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    • pp.19-26
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    • 2005
  • The last two decades have shown a marked expansion in publications of diverse effects of Panax ginseng. Ginsenosides, as active ingredients of Panax ginseng, are saponins found in only ginseng. Recently, a line of evidences shows that ginsenosides regulate various types of ion channel activity such as $Ca^{2+},\;K^+,\;Na^+,\;Cl^-$, or ligand gated ion channels (i.e. $5-HT_3$, nicotinic acetylcholine, or NMDA receptor) in neuronal, non-neuronal cells, and heterologously expressed cells. Ginsenosides inhibit voltage-dependent $Ca^{2+},\;K^+,\;and\;Na^+$ channels, whereas ginsenosides activate $Ca^{2+}-activated\;Cl^-\;and\;Ca^{2+}-activated\;K^+$ channels. Ginsenosides also inhibit excitatory ligand-gated ion channels such as $5-HT_3$, nicotinic acetylcholine, and NMDA receptors. This review will introduce recent findings on the ginsenoside-induced differential regulations of ion channel activities and will further expand the possibilities how these ginsenoside-induced ion channel regulations are coupled to biological effects of Panax ginseng.

Lactobacillus plantarum G72 Showing Production of Folate and Short-chain Fatty Acids

  • Jang, Hye Ji;Lee, Na-Kyoung;Paik, Hyun-Dog
    • Microbiology and Biotechnology Letters
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    • v.49 no.1
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    • pp.18-23
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    • 2021
  • The aim of this study was to determine the production of folate, short chain fatty acids (SCFAs), and antimicrobial activity exhibited by Lactobacillus plantarum G72 for potential dietary application in pregnant women. L. plantarum G72 has been reported to possess characteristic activities and functionality including β-galactosidase activity and antioxidant activities. L. plantarum G72 showed antibacterial activity against pathogenic bacteria (Listeria monocytogenes ATCC 15313, Salmonella typhimurium P99, Escherichia coli ATCC 25922, and Staphylococcus aureus KCCM 11335) using a modified method, and formation of the largest inhibition zone was observed against S. aureus KCCM 11335 (12.0-17.0 mm). The adherence of four food-borne pathogenic bacteria to HT-29 cells was inhibited by L. plantarum G72 (0.13 to 0.92 log CFU/ml). The most considerable inhibition of adherence to HT-29 cells was observed by using L. plantarum G72 against S. typhimurim P99. Additionally, folate production by L. plantarum G72 was 50.1 ng/ml, and L. plantarum G72 produced relatively more lactic acid (11,176.73 mg/kg) than acetic, propionic, or butyric acids. Therefore, the results of this study suggest that L. plantarum G72 may serve as a multifunctional food additive in the health industry.

Differential Role of Solvents on Human Cytochrome P450 2El Activity in Intact HepG2 Cells (HepG2 세포에서 용매에 의한 차별적인 사람 싸이토크롬 P450 2E1활성 변화)

  • 최달웅
    • Journal of Environmental Health Sciences
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    • v.29 no.3
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    • pp.9-15
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    • 2003
  • The modification of CYP2El activity is a matter of considerable interest because of its role in the metabolic activation of a variety of environmental toxicants. In the present study, the time-course of changes in human CYP2El activities was determined following treatment with solvents (acetone, dimethylsulphoxide or pyridine) using intact HepG2 cells transfected by human CYP2El. Hydroxylation of chlorzoxazone was used for the measurement of CYP2El activity. CYP2E1 protein level was increased upon cultivation of cells in the presence of the solvents for 24 hr. Determination of CYP2El activities after 24 ht cultivation with the solvents demonstrated that acetone or dimethylsulphoxide increased, whereas pyridine inhibited the activities. This differential effect of the solvents on CYP2El activities persisted to subsequent 24 ht. Competitive inhibition study suggested that pyridine has stronger binding affinity to CYP2E1 than acetone or dimethylsulphoxide. These results demonstrate that different binding affinity of the solvents to CYP2El plays important role in determining real CYP2El activity in intact cells after exposure to the solvents. Present study would be helpful in precise understanding of human CYP2El-mediated toxicity.

Effect of Solvent Extracts from Sargassum hemiphyllum on Inhibition of Growth of Human Cancer Cell Lines and Antioxidant Activity (짝잎모자반(Sargassum hemiphyllum)의 암세포주 증식 억제 및 항산화 효과)

  • Choi, Hyung-Ju;Seo, Young-Wan;Lim, Sun-Young
    • Journal of Life Science
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    • v.17 no.11
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    • pp.1533-1538
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    • 2007
  • This study was carried out to determine the inhibitory effects of solvent extracts from Sargassum hemiphyllum on growth of cancer cell lines (AGS human gastric adenocarcinoma and HT-29 human colon cancer cells) and production of lipid peroxides. Inhibitory effects of acetone with methylene chloride extract from S. hemiphyllum on the growth of AGS and HT-29 cancer cells were increased as dose dependent patterns (p<0.05). The methanol extract was more effective on inhibition of growth of AGS. The treatments of hexane, 85% aq. methanol, butanol and water fractions significantly inhibited the growth of cancer cells (p<0.05) and the inhibitory effect was stronger in HT-29. In DCFH-DA (dichlorodihydrofluorescin diacetate) assay, acetone with methylene chloride and methanol extracts showed a stronger inhibitory effect on the production of cellular lipid peroxides (p<0.05) compared with the butanol and hexane fractions. These results indicate that the consumption of S. hemiphyllum may be recommended as a potent functional food for preventing cellular oxidation and cancer.

In vitro Anti-tumor Effect of an Engineered Vaccinia Virus in Multiple Cancer Cells and ABCG2 Expressing Drug Resistant Cancer Cells (재조합 백시니아 바이러스의 다양한 암세포 및 ABCG2 과발현 내성 암세포에 대한 항 종양 효과 연구)

  • Park, Ji Hye;Yun, Jisoo;Heo, Jeong;Hwang, Tae Ho;Kwon, Sang Mo
    • Journal of Life Science
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    • v.26 no.7
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    • pp.835-846
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    • 2016
  • Chemo-resistance is the biggest issue of effective cancer therapy. ABCG2 is highly correlated with multi-drug resistance, and represent a typical phenotype of multiple cancer stem-like cells. Accumulating evidence recently reported that oncolytic viruses represent a new strategy for multiple aggressive cancers and drug resistant cancers including cancer stem cell-like cells and ABCG2 expressing cells. In this study, we generated an evolutionally engineered vaccinia virus, SLJ-496, for drug-resistant cancer therapy. We first showed that SLJ-496 treatment enhanced tumor affinity using cytopathic effect assay, plaque assay, as well as cell viability assay. Next, we clearly demonstrated that in vitro SLJ-496 treatment represents significant cytotoxic effect in multiple cancers including colorectal cancer cells (HT-29, HCT-116, HCT-8), gastric cancer cells (AGS, NCI-N87, MKN-28), Hepatocellular carcinoma cells (SNU-449, SNU-423, SNU-475, HepG2), as well as mesothelioma cell (NCI-H226, NCI-H28, MSTO-221h). Highly ABCG2 expressing HT-29 cells represent cancer stem like phenotype including stem cell marker expression, and self-renewal bioactivities. Interestingly, we demonstrated that in vitro treatment of SLJ-496 showed significant cytotoxicity effect, as well as viral replication capacity in ABCG2 overexpressing cell. In addition, we also demonstrated the cytotoxic effect of SLJ-496 in Adriamycin-resistant cell lines, SNU-620 and ADR-300. Taken together, these findings provide us a pivotal clue that cancer therapy using SLJ-496 vaccinia virus might be new therapeutic strategy to overcome ABCG2 expressing cancer stem-like cell and multiple chemo-resistance cancer cells.

Immune-triggering effect of the foodborne parasite Kudoa septempunctata through the C-type lectin Mincle in HT29 cells

  • Shin, Ji-Hun;Yang, Jung-Pyo;Seo, Seung-Hwan;Kim, Sang-Gyun;Kim, Eun-Min;Ham, Do-Won;Shin, Eun-Hee
    • BMB Reports
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    • v.53 no.9
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    • pp.478-483
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    • 2020
  • Kudoa septempunctata is a myxozoan parasite that causes food poisoning in individuals consuming olive flounder. The present study aimed to investigate the currently insufficiently elucidated early molecular mechanisms of inflammatory responses in the intestine owing to parasite ingestion. After Kudoa spores were isolated from olive flounder, HT29 cells were exposed to spores identified to be alive using SYTO-9 and propidium iodide staining or to antigens of Kudoa spores (KsAg). IL-1β, IL-8, TNF-α and NFKB1 expression and NF-κB activation were assessed using real-time PCR, cytokine array and western blotting. The immunofluorescence of FITC-conjugated lectins, results of ligand binding assays using Mincle-Fc and IgG-Fc, CLEC4E expressions in response to KsAg stimulation, and Mincle-dependent NF-κB activation were assessed to clarify the early immune-triggering mechanism. Inflammatory cytokines (IL-1β, GM-CSF and TNF-α), chemokines (IL-8, CCL2, CCL5 and CXCL1) and NF-κB activation (pNF-κB/NF-κB) in HT29 cells increased following stimulation by KsAg. The immunofluorescence results of spores and lectins (concanavalin A and wheat germ agglutinin) suggested the importance of Mincle in molecular recognition between Kudoa spores and intestinal cells. Practically, data for Mincle-Fc and KsAg binding affinity, CLEC4E mRNA expression, Mincle immunofluorescence staining and hMincle-dependent NF-κB activation demonstrated the involvement of Mincle in the early immune-triggering mechanism. The present study newly elucidated that the molecular recognition and immune-triggering mechanism of K. septempunctata are associated with Mincle on human intestinal epithelial cells.