Hye Gwang Jeong

Chungnam National University, Daiden, Daejeon, South Korea

Are you Hye Gwang Jeong?

Claim your profile

Publications (228)631.39 Total impact

  • Hyung Gyun Kim · Eun Hee Han · Ji Hye Im · Eun Ji Lee · Sun Woo Jin · Hye Gwang Jeong
    [Show abstract] [Hide abstract]
    ABSTRACT: Caffeic acid phenethyl ester (CAPE), a natural component of propolis, is reported to have anticarcinogenic properties, although its precise chemopreventive mechanism remains unclear. In this study, we examined the effects of CAPE on 3-methylcholanthrene (3-MC)-induced CYP1A1 expression and activities. CAPE reduced the formation of the benzo[a]pyrene-DNA adduct. Moreover, CAPE inhibited 3-MC-induced CYP1A1 activity, mRNA expression, protein level, and promoter activity. CAPE treatment also decreased 3-MC-inducible xenobiotic-response element (XRE)-linked luciferase, aryl hydrocarbons receptor (AhR) transactivation and nuclear localization. CAPE induced hypoxia inducible factor-1α (HIF-1α) protein level and HIF-1α responsible element (HRE) transcriptional activity. CAPE-mediated HIF-1α reduced 3-MC-inducible CYP1A1 protein expression. Taken together, CAPE decreases 3-MC-mediated CYP1A1 expression, and this inhibitory response is associated with inhibition of AhR and HIF-1α induction. Copyright © 2015. Published by Elsevier Inc.
    Biochemical and Biophysical Research Communications 08/2015; 465(3). DOI:10.1016/j.bbrc.2015.08.060 · 2.30 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Here, we show the newly synthesized and potent ALK inhibitor having similar scaffold to KRCA-0008, which was reported previously, and its molecular mechanism against cancer cells harboring EML4-ALK fusion protein. Through ALK wild type enzyme assay, we selected two compounds, KRCA-0080 and KRCA-0087, which have trifluoromethyl instead of chloride in R2 position. We characterized these newly synthesized compounds by in vitro and in vivo assays. Enzyme assay shows that KRCA-0080 is more potent against various ALK mutants, including L1196M, G1202R, T1151_L1152insT, and C1156Y, which are seen in crizotinib-resistant patients, than KRCA-0008 is. Cell based assays demonstrate our compounds downregulate the cellular signaling, such as Akt and Erk, by suppressing ALK activity to inhibit the proliferation of the cells harboring EML4-ALK. Interestingly, our compounds induced strong G1/S arrest in H3122 cells leading to the apoptosis, which is proved by PARP-1 cleavage. In vivo H3122 xenograft assay, we found that KRCA-0080 shows significant reduction in tumor size compared to crizotinib and KRCA-0008 by 15-20%. Conclusively, we report a potent ALK inhibitor which shows significant in vivo efficacy as well as excellent inhibitory activity against various ALK mutants. Copyright © 2015. Published by Elsevier Inc.
    Biochemical and Biophysical Research Communications 07/2015; 464(3). DOI:10.1016/j.bbrc.2015.07.027 · 2.30 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Scutellaria baicalensis is one of the most widely used herbal medicines in East Asia. Because baicalein and baicalin are major components of this herb, it is important to understand the effects of these compounds on drug metabolizing enzymes, such as cytochrome P450 (CYP), for evaluating herb-drug interaction. The effects of baicalin and baicalein on activities of ethoxyresorufin O-deethylase (EROD), methoxyresorufin O-demethylase (MROD), benzyloxyresorufin O-debenzylase (BROD), p-nitrophenol hydroxylase and erythromycin N-demethylase were assessed in rat liver microsomes in the present study. In addition, the pharmacokinetics of caffeine and its three metabolites (i.e., paraxanthine, theobromine and theophylline) in baicalin-treated rats were compared with untreated control. As results, EROD, MROD and BROD activities were inhibited by both baicalin and baicalein. However, there were no significant differences in the pharmacokinetic parameters of oral caffeine and its three metabolites between control and baicalin-treated rats. When the plasma concentration of baicalin was determined, the maximum concentration of baicalin was below the estimated IC50 values observed in vitro. In conclusion, baicalin had no effects on the pharmacokinetics of caffeine and its metabolites in vivo, following single oral administration in rats.
    Biomolecules and Therapeutics 03/2015; 23(2):201-206. DOI:10.4062/biomolther.2014.134 · 1.73 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: We investigated the inhibitory effects of Platycodon grandiflorum root-derived saponins (Changkil saponins: CKS) on ovalbumin-induced airway inflammation in mice. CKS suppressed leukocytes number, IgE, Th1/Th2 cytokines, and MCP-1 chemokine secretion in bronchoalveolar lavage fluid. Also ovalbumin-increased MUC5AC, MMP-2/9, and TIMP-1/-2 mRNA expression, NF-κB activation, leukocytes recruitment, and mucus secretion was inhibited by CKS treatment. Moreover, the active component of CKS, platyconic acid A (PA), suppressed PMA-induced MUC5AC mRNA expression (from 2.1 ± 0.2 to 1.1 ± 0.1) by inhibiting NF-κB activation (from 2.3 ± 0.2 to 1.2 ± 0.1) via Akt (from 3.7 ± 0.3 to 2.1 ± 0.2) (respectively; p < 0.01) in A549 cells. Therefore, we demonstrate that CKS or PA suppressed the development of respiratory inflammation, hyperresponsiveness, and remodeling by reducing allergic responses, and they may be potential herbal drugs for allergen-induced respiratory disease prevention.
    Journal of Agricultural and Food Chemistry 01/2015; 63(5). DOI:10.1021/jf5043954 · 2.91 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Despite efforts to develop efficient chemotherapeutic drug strategies to treat cancer, acquired drug resistance is a commonly encountered problem. In the present study, to investigate this phenomenon, human A549 lung cancer cells resistant to the topoisomerase inhibitor etoposide (A549RT‑eto) were used and compared with A549 parental cells. A549RT‑eto cells demonstrated increased resistance to etoposide‑induced apoptosis when compared with A549 parental cells. Notably, A549RT‑eto cells were observed to exhibit greater levels of histone deacetylase 4 (HDAC4), phospho‑Stat1 and P‑glycoprotein [P‑gp; encoded by the multidrug resistance 1 (MDR1) gene], compared with A549 cells. To address whether HDAC4 protein is involved in etoposide resistance in A549 cells, A549RT‑eto cells were treated with trichostatin A (TSA; an HDAC inhibitor) during etoposide treatment. The combined treatment was demonstrated to enhance etoposide‑induced apoptosis and reduce expression levels of HDAC4, P‑gp and phospho‑Stat1. In addition, the suppression of Stat1 with siRNA enhanced etoposide‑induced apoptosis and reduced the expression levels of HDAC4 and P‑gp, suggesting that Stat1 is essential in the regulation of resistance to etoposide, and in the upregulation of P‑gp. Notably, TSA treatment reduced P‑gp transcript levels but Stat1 siRNA treatment did not, suggesting that P‑gp is regulated by HDAC at the transcriptional level and by Stat1 at the post‑transcriptional level. These results suggest that the upregulation of Stat1 and HDAC4 determines etoposide resistance through P‑gp expression in human A549 lung cancer cells.
    Molecular Medicine Reports 11/2014; 11(3). DOI:10.3892/mmr.2014.2949 · 1.55 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: To investigate the nephrotoxic potential of melamine (MEL) and cyanuric acid (CA) in male Sprague-Dawley rats, 7-d repeated-dose studies were performed. The experimental groups of MEL100 and CA100 were orally administered with MEL and CA at 100 mg/kg/d for 7 d, respectively. In groups dosed with MEL-CA mixtures, melamine and cyanuric acid (1:1) were simultaneously administered at 4, 20, or 100 mg/kg/d for 7 d (i.e., MEL-CA4, MEL-CA20, or MEL-CA100, respectively). Body weights were not markedly affected in MEL100, CA100, and MEL-CA4 groups, but significantly reduced in MEL-CA 20 and 100 rats. Most parameters determined in sera and tissues were not markedly altered in MEL100, CA100, and MEL-CA4-treated rodents. However, BUN, creatinine, total protein, and kidney weights were significantly increased in MEL-CA20- and MEL-CA100-treated animals. Renal histopathologic findings also revealed signs of toxicity, including tubular dilatation, crystal deposition, granulomatous tubulo-interstitial inflammation, and tubular necrosis with regeneration. Data suggested that the combination of MEL and CA might be responsible for observed nephrotoxicity that was not seen following individual exposure to either MEL or CA alone. Subsequently, the concentrations of MEL and CA were determined in serum, urine, and kidney tissues by using liquid chromatography-mass spectrometry. Toxicokinetic studies indicated that MEL or CA alone might be eliminated almost completely within 24 h after dosing showing no accumulation in kidney. However, the combined MEL-CA dose produced marked accumulation of chemicals in blood and kidneys. These results suggested that combined MEL and CA might produce renal toxicity due to significant chemical accumulation in kidney accompanied by low excretion.
    Journal of Toxicology and Environmental Health Part A 10/2014; 77(22-24):1346-58. DOI:10.1080/15287394.2014.951592 · 2.35 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Endosulfan (1,4,5,6,7,7-hexachloro-8,9,10-trinorborn-5-en-2,3-ylenebismet-hylene) is correlated with endocrine disruption, reproductive, and immune dysfunctions. Recently, endosulfan was shown to have an effect on inflammatory pathways, but its influence on cyclooxygenase-2(COX-2) expression is unclear. This study investigated the effects of COX-2 and molecular mechanisms by endosulfan in murine macrophage RAW 264.7 cells. Endosulfan significantly induced COX-2 protein and mRNA levels, as well as COX-2 promoter-driven luciferase activity and the production of prostaglandin E2, a major COX-2 metabolite. Transfection experiments with several human COX-2 promoter constructs revealed that endosulfan activated NF-κB, C/EBP, AP-1, and CREB. Moreover, Akt and mitogen-activated protein kinases (MAPK) were significantly activated by endosulfan. Moreover, endosulfan increased production of the ROS and the ROS-producing NAPDH-oxidase (NOX) family oxidases, NOX2, and NOX3. Endosulfan-induced Akt/MAPK pathways and COX-2 expression were attenuated by DPI, a specific NOX inhibitor, and the ROS scavenger N-acetylcysteine. These results demonstrate that endosulfan induces COX-2 expression via NADPH oxidase, ROS, and Akt/MAPK pathways. These findings provide further insight into the signal transduction pathways involved in the inflammatory effects of endosulfan.
    Archive für Toxikologie 09/2014; DOI:10.1007/s00204-014-1359-7 · 5.98 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Induction of cytochrome P450 (CYP) 1A1 and CYP1B1 by environmental xenobiotic chemicals or endogenous ligands through the activation of the aryl hydrocarbon receptor (AhR) has been implicated in a variety of cellular processes related to cancer, such as transformation and tumorigenesis. Here, we investigated the effects of the anti-diabetes drug metformin on expression of CYP1A1 and CYP1B1 in breast cancer cells under constitutive and inducible conditions. Our results indicated that metformin down-regulated the expression of CYP1A1 and CYP1B1 in breast cancer cells under constitutive and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-induced conditions. Down-regulation of AhR expression was required for metformin-mediated decreases in CYP1A1 and CYP1B1 expression, and the metformin-mediated CYP1A1 and CYP1B1 reduction is irrelevant to estrogen receptor α (ERα) signaling. Furthermore, we found that metformin markedly down-regulated Sp1 protein levels in breast cancer cells. The use of genetic and pharmacological tools revealed that metformin-mediated down-regulation of AhR expression was mediated through the reduction of Sp1 protein. Metformin inhibited endogenous AhR ligand-induced CYP1A1 and CYP1B1 expression by suppressing tryptophan-2,3-dioxygenase (TDO) expression in MCF-7 cells. Finally, metformin inhibits TDO expression through a down-regulation of Sp1 and glucocorticoid receptor (GR) protein levels. Our findings demonstrate that metformin reduces CYP1A1 and CYP1B1 expression in breast cancer cells by down-regulating AhR signaling. Metformin would be able to act as a potential chemopreventive agent against CYP1A1 and CYP1B1-mediated carcinogenesis and development of cancer.
    Toxicology and Applied Pharmacology 08/2014; 280(1). DOI:10.1016/j.taap.2014.07.021 · 3.71 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Purpose: The consequences of precipitously rising allergic skin inflammation rates worldwide have accelerated the risk of atopic dermatitis (AD). Natural product-based agents with good efficacy and low risk of side effects offer promising prevention and treatment strategies for inflammation-related diseases. We have already reported that Platycodon grandiflorum root-derived saponins (Changkil saponins, CKS) have many pharmacological effects, including anti-inflammatory and anti-allergic effects, but its influence on AD remains unclear. Therefore, we evaluated the inhibitory effect of CKS, mainly platycodin D, on AD-like skin symptoms in mice and the possible mechanisms in cells. Methods: Mice were sensitized and challenged with 2,4-dinitrochlorobenzene (DNCB). Four weeks after challenge, mice were treated with oral administration of CKS for 4 weeks. In addition, cells were used to evaluate the effect of CKS, mainly platycodin D, on the TARC expression regulated mechanism. Results: CKS attenuated DNCB-induced dermatitis severity, serum levels of IgE and TARC, and mRNA expression of TARC, TNF-α, IFN-γ, IL-4, IL-5, and IL-13 in mice. Histopathological examination showed reduced thickness of the epidermis/dermis and dermal infiltration of inflammatory cells and mast cells in the ears. Moreover, CKS and platycodin D inhibited TNF-α/IFN-γ-induced TARC expression through the suppression of NF-κB and STAT1 and induction of Nrf2/ARE-mediated hemeoxygenase-1 (HO-1) expression in cells. Conclusion: We suggest that CKS and platycodin D inhibited the development of AD-like skin symptoms by regulating cytokine mediators and may be an effective alternative therapy for AD-like skin symptoms.
    Phytomedicine 07/2014; 21(8-9). DOI:10.1016/j.phymed.2014.04.011 · 3.13 Impact Factor
  • Minh Truong Do · Hyung Gyun Kim · Jae Ho Choi · Hye Gwang Jeong
    [Show abstract] [Hide abstract]
    ABSTRACT: Sirtuin 1 (Sirt1) plays an important role in cellular redox balance and resistance to oxidative stress. Sirt1 exhibits oncogenic properties in wild-type p53 cancer cells, while Sirt1 acts as a tumor suppressor in p53-mutated cancer cells. Here, we investigated the effects of metformin on Sirt1 expression in several cancer cell lines. Using human cancer cell lines that exhibit differential expression of p53, we found that metformin reduced Sirt1 protein levels in cancer cells bearing wild-type p53, but did not affect Sirt1 protein levels in cancer cell lines harboring mutant forms of p53. Metformin-induced p53 protein levels in wild-type p53 cancer cells resulted in up-regulation of microRNA (miR)-34a. The use of a miR-34a inhibitor confirmed that metformin-induced miR-34a was required for Sirt1 down-regulation. Metformin suppressed peroxisome proliferator-activated receptor gamma (PPARγ) coactivator-1 alpha (Pgc-1α) expression and its downstream target Nrf2 in MCF-7 cells. Genetic tools demonstrated that the reduction of Sirt1 and Pgc-1α by metformin caused Nrf2 down-regulation via suppression of PPARγ transcriptional activity. Metformin reduced heme oxygenase-1 (HO-1) and superoxide dismutase 2 (SOD2) but up-regulated catalase expression in MCF-7 cells. Metformin-treated MCF-7 cells had no increase in basal levels of reactive oxygen species (ROS) but were more susceptible to oxidative stress. Furthermore, up-regulation of death receptor (DR) 5 by metformin-mediated Sirt1 down-regulation enhanced the sensitivity of wild-type p53 cancer cells to TRAIL-induced apoptosis. Our results demonstrated that metformin induces miR-34a to suppress the Sirt1/Pgc-1α/Nrf2 pathway and increases susceptibility of wild-type p53 cancer cells to oxidative stress and TRAIL-induced apoptosis.
    Free Radical Biology and Medicine 06/2014; 74. DOI:10.1016/j.freeradbiomed.2014.06.010 · 5.74 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: TRAIL induces apoptosis in a variety of tumor cells. However, development of resistance to TRAIL is a major obstacle to more effective cancer treatment. Therefore, novel pharmacological agents that enhance sensitivity to TRAIL are necessary. In the present study, we investigated the molecular mechanisms by which ilimaquinone isolated from a sea sponge sensitizes human colon cancer cells to TRAIL. Ilimaquinone pretreatment significantly enhanced TRAIL-induced apoptosis in HCT 116 cells and sensitized colon cancer cells to TRAIL-induced apoptosis through increased caspase-8, -3 activation, PARP cleavage, and DNA damage. Ilimaquinone also reduced the cell survival proteins Bcl2 and Bcl-xL, while strongly up-regulating death receptor (DR) 4 and DR5 expression. Induction of DR4 and DR5 by ilimaquinone was mediated through up-regulation of CCAAT/enhancer-binding protein homologous protein (CHOP). The up-regulation of CHOP, DR4 and DR5 expression was mediated through activation of extracellular-signal regulated kinase (ERK) and p38 mitogen-activated protein kinase (MAPK) signaling pathways. Finally, the generation of ROS was required for CHOP and DR5 up-regulation by ilimaquinone. These results demonstrate that ilimaquinone enhanced the sensitivity of human colon cancer cells to TRAIL-induced apoptosis through ROS-ERK/p38 MAPK-CHOP-mediated up-regulation of DR4 and DR5 expression, suggesting that ilimaquinone could be developed into an adjuvant chemotherapeutic drug.
    Food and Chemical Toxicology 06/2014; 71. DOI:10.1016/j.fct.2014.06.001 · 2.90 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Protein kinase A (PKA), a serine/threonine kinase, regulates bone formation, and enhances Bone morphogenetic protein (BMP)-induced osteoblast differentiation. However, the mechanisms of how PKA controls the cellular response to BMP are not well known. We investigated the effects of modulating PKA activity during BMP2-induced osteoblast differentiation, and found that PKA regulates the function of Dlx3. Dlx3 plays crucial roles in osteoblast differentiation and it is expressed in most skeletal elements during development. We found that PKA activation increases BMP2-induced expression of Dlx3 protein, and enhances the protein stability, DNA binding, and transcriptional activity of Dlx3. In addition, PKA activation induces the phosphorylation of Dlx3 at consensus PKA phosphorylation target site(s). Lastly, substitution of serine 10 in Dlx3 to alanine significantly reduces, if not completely abolishes, the phosphorylation of Dlx3 and the regulation of Dlx3 function by PKA. These results suggest that Dlx3 is a novel target of PKA, and that PKA mediates BMP signaling during osteoblast differentiation, at least in part, by phosphorylating Dlx3 and modulating the protein stability and function of Dlx3. © 2014 Wiley Periodicals, Inc.
    Journal of Cellular Biochemistry 06/2014; 115(11). DOI:10.1002/jcb.24872 · 3.26 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: A-disintegrin and metalloproteinase 10 (ADAM10) is involved in the generation of amyloid-β (Aβ) during amyloid precursor protein (APP) processing, and has a protective effect against Aβ neurotoxicity. We explored how metallothionein-III (MT-III) is regulated in the non-amyloidogenic pathway to generate soluble APPα (sAPPα). MT-ІІІ increased sAPPα levels and reduced Aβ peptide levels, but did not affect ADAM10 expression. However, MT-III increased the activity of ADAM10. MT-ІІІ-induced sAPPα secretion, and Aβ peptide formation was blocked by specific inhibitors of furin, proprotein convertase7 (PC7), and PKCα. These results demonstrate that MT-ІІІ increases the amount of active ADAM10 in association with furin, PC7 and PKCα.
    FEBS Letters 05/2014; 588(14). DOI:10.1016/j.febslet.2014.05.017 · 3.17 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Leptin, a hormone with multiple biological actions, is produced predominantly by adipose tissue. Among its functions, leptin can stimulate tumour cell growth. Oestrogen receptor α (ERα), which plays an essential role in breast cancer development, can be transcriptionally activated in a ligand-independent manner. In this study, we investigated the effect of leptin on CYP1B1 expression and its mechanism in breast cancer cells. Leptin induced CYP1B1 protein, messenger RNA expression and promoter activity in ERα-positive MCF-7 cells but not in ERα-negative MDA-MB-231 cells. Additionally, leptin increased 4-hydroxyoestradiol in MCF-7 cells. Also, ERα knockdown by siRNA significantly blocked the induction of CYP1B1 expression by leptin, indicating that leptin induced CYP1B1 expression via an ERα-dependent mechanism. Transient transfection with CYP1B1 deletion promoter constructs revealed that the oestrogen response element (ERE) plays important role in the up-regulation of CYP1B1 by leptin. Furthermore, leptin stimulated phosphorylation of ERα at serine residues 118, and 167 and increased ERE-luciferase activity, indicating that leptin induced CYP1B1 expression by ERα activation. Finally, we found that leptin activated ERK, and Akt signalling pathways which are upstream kinases related to ERα phosphorylation induced by leptin. Taken together, our results indicate that leptin-induced CYP1B1 expression is mediated by ligand-independent activation of the ERα pathway as a result of the activation of ERK and Akt in MCF-7 cells.
    Toxicology and Applied Pharmacology 05/2014; 277(1). DOI:10.1016/j.taap.2014.03.003 · 3.71 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Effects of diallyl sulfide (DAS) on thioacetamide-induced hepatotoxicity and immunotoxicity were investigated. When male Sprague-Dawley rats were treated orally with 100, 200 and 400 mg/kg of DAS in corn oil for three consecutive days, the activity of cytochrome P450 (CYP) 2E1-selective p-nitrophenol hydroxylase was dose-dependently suppressed. In addition, the activities of CYP 2B-selective benzyloxyresorufin O-debenzylase and pentoxyresorufin O-depentylase were significantly induced by the treatment with DAS. Western immunoblotting analyses also indicated the suppression of CYP 2E1 protein and/or the induction of CYP 2B protein by DAS. To investigate a possible role of metabolic activation by CYP enzymes in thioacetamide-induced hepatotoxicity, rats were pre-treated with 400 mg/kg of DAS for 3 days, followed by a single intraperitoneal treatment with 100 and 200 mg/kg of thioacetamide in saline for 24 hr. The activities of serum alanine aminotransferase and aspartate aminotransferase significantly elevated by thioacetamide were protected in DAS-pretreated animals. Likewise, the suppressed antibody response to sheep erythrocytes by thioacetamide was protected by DAS pretreatment in female BALB/c mice. Taken together, our present results indicated that thioacetamide might be activated to its toxic metabolite(s) by CYP 2E1, not by CYP 2B, in rats and mice.
    Biomolecules and Therapeutics 02/2014; 22(2):149-54. DOI:10.4062/biomolther.2014.016 · 1.73 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Transforming growth factor β (TGFβ) is a multifunctional cytokine that induces growth arrest, tissue fibrosis, and epithelial-mesenchymal transition (EMT) through activation of Smad and non-Smad signaling pathways. EMT is the differentiation switch by which polarized epithelial cells differentiate into contractile and motile mesenchymal cells. Our previous studies have shown that saponins from the roots of Platycodon grandiflorum (CKS) have antiinflammatory, antioxidant, antimetastatic, and hepatoprotective effects. In this study, we investigated the inhibitory effect of CKS on TGFβ1-induced alterations characteristic of EMT in human lung carcinoma A549 cells. We found that CKS-treated cells displayed inhibited TGFβ1-mediated E-cadherin downregulation and Vimentin upregulation and also retained epithelial morphology. Furthermore, TGFβ1-increased Snail expression, a repressor of E-cadherin and an inducer of the EMT, was reduced by CKS. CKS inhibited TGFβ1-induced phosphorylation of Akt, ERK1/2, and glycogen synthase kinase-3β (GSK-3β). Inhibition of PI3K/Akt and ERK1/2 also blocked TGFβ1-induced GSK-3β phosphorylation and Snail activation. Furthermore, TGFβ1-increased Snail expression was reduced by selective inhibitors of Akt and ERK1/2. Moreover, CKS treatment attenuated TGFβ1-induced Smad2/3 phosphorylation and upregulated Smad7 expression. These results indicate that pretreatment with the CKS inhibits the TGFβ1-induced EMT through PI3K/Akt, ERK1/2, GSK-3β and Smad2/3 in human lung carcinoma cells.
    Nutrition and Cancer 12/2013; 66(1). DOI:10.1080/01635581.2014.853087 · 2.32 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The biological activity of Mastixia arborea (MA) relates to inflammation, but the underlying mechanisms are largely unknown. We confirmed the anti-inflammatory effects of a methanol extract of MA extract on lipopolysaccharide (LPS)-stimulated RAW264.7 mouse macrophage cells and carrageenan-induced mice paw edema. The MA extract significantly inhibited nitric oxide (NO), prostaglandin E2 (PGE2), interleukin-1β (IL-1β), and IL-6 production in LPS-stimulated RAW264.7 cells. In vitro expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) was suppressed by the extract. The extract attenuated acute inflammatory responses in carrageenan-induced mice paw edema. A mechanism study indicated that translocation of the NF-κB (p65) subunit into the nucleus and phosphorylation of ERK and JNK were inhibited by the extract. These results indicate that the extract is an effective suppressor of the inflammatory response, blocking the phosphorylation of ERK and JNK and the translocation of NF-κB in macrophages, thereby producing an anti-inflammatory effect in vivo.
    Bioscience Biotechnology and Biochemistry 12/2013; 77(12). DOI:10.1271/bbb.130429 · 1.06 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Piperine is a bioactive component of black pepper, Piper nigrum Linn, commonly used for daily consumption and in traditional medicine. Here, the molecular mechanisms by which piperine exerts antitumor effects in HER2-overexpressing breast cancer cells was investigated. The results showed that piperine strongly inhibited proliferation and induced apoptosis through caspase-3 activation and PARP cleavage. Furthermore, piperine inhibited HER2 gene expression at the transcriptional level. Blockade of ERK1/2 signaling by piperine significantly reduced SREBP-1 and FAS expression. Piperine strongly suppressed EGF-induced MMP-9 expression through inhibition of AP-1 and NF-κB activation by interfering with ERK1/2, p38 MAPK, and Akt signaling pathways resulting in a reduction in migration. Finally, piperine pretreatment enhanced sensitization to paclitaxel killing in HER2-overexpressing breast cancer cells. Our findings suggest that piperine may be a potential agent for the prevention and treatment of human breast cancer with HER2 overexpression.
    Food Chemistry 12/2013; 141(3):2591-9. DOI:10.1016/j.foodchem.2013.04.125 · 3.39 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Genipin is a compound found in gardenia fruit extract with diverse pharmacological activities. However, the mechanism underlying genipin-induced cyclooxygenase-2 (COX-2) expression remains unknown. In this study, we investigated the effects of genipin on COX-2 expression and determined that exposure to genipin dose-dependently enhanced the production of prostaglandin E2 (PGE2), a major COX-2 metabolite, in RAW 264.7 cells. These effects were mediated by genipin-induced activation of the COX-2 promoter, as well as AP-1 and NF-κB luciferase constructs. Phosphatidylinositol-3-kinase/Akt and MAPKs were also significantly activated by genipin, and Akt and MAPKs inhibitors (PD98059, SB20358, SP600125, and LY294002) inhibited genipin-induced COX-2 expression. Moreover, genipin increased production of the ROS and the ROS-producing NAPDH-oxidase (NOX) family oxidases, NOX2 and NOX3. Inhibition of NADPH with diphenyleneiodonium attenuated ROS production, COX-2 expression and NF-κB and AP-1 activation. These results suggest that the molecular mechanism mediating ROS-dependent COX-2 up-regulation and PGE2 production by genipin involves activation of Akt, MAPKs and AP-1/NF-κB.
    Food and chemical toxicology: an international journal published for the British Industrial Biological Research Association 11/2013; 64. DOI:10.1016/j.fct.2013.11.035 · 2.90 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: It has been reported that the selective inhibitors of 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) have considerable potential for treating type 2 diabetes mellitus, metabolic syndrome and inflammation. In the present study, we investigated the anti-diabetic and anti-inflammatory effects of N-(5-carbamoyladamantan-2-yl)-3-((2-fluorophenyl) sulfonyl)thiazolidine-2-carboxamide (KR-67105), a novel 11β-HSD1 inhibitor, in diabetic mice model and preadipocyte model. KR-67105 concentration dependently inhibited 11β-HSD1 activity in human and mouse 11β-HSD1 overexpressing cells and mouse 3T3-L1 adipocytes. Furthermore, KR-67105 concentration-dependently inhibited 11β-HSD1 activity in the ex vivo assay of C57BL/6 mice. In the study with diet-induced obese (DIO) mice, the administration of KR-67105 (100mg/kg/day, orally for 28 days) improved the glucose tolerance and insulin sensitivity as determined by the oral glucose tolerance test and the insulin tolerance test. Anti-diabetic effect by KR-67105 was associated with the suppression of diabetic related genes expression in liver and fat. Furthermore, KR-67105 suppressed 11β-HSD1 activity in liver and fat of diabetic mice, but showed no effect on adrenal grand weight/body weight ratio and plasma corticosterone concentration in diabetic mice. In 3T3-L1 preadipocytes, cortisone induced the mRNA of inflammatory cytokines and 11β-HSD1 and reactive oxygen species formation. This effect was abolished by co-incubation with KR-67105 in a concentration-dependent manner. Moreover, KR-67105 attenuated cortisone induced iNOS expression and phosphorylation of NF-κB p65, p38, and ERK1/2 MAPK in preadipocytes. Taken together, it is concluded that a selective 11β-HSD1 inhibitor, KR-67105, may provide a new therapeutic window in the prevention and treatment of type 2 diabetes with chronic inflammation without toxicity.
    European journal of pharmacology 10/2013; 721(1-3). DOI:10.1016/j.ejphar.2013.09.052 · 2.53 Impact Factor

Publication Stats

4k Citations
631.39 Total Impact Points


  • 2009–2015
    • Chungnam National University
      • College of Pharmacy
      Daiden, Daejeon, South Korea
  • 1996–2013
    • Chosun University
      • • College of Pharmacy
      • • Department of Pharmacy
      • • Research Center for Proteineous Materials (RCPM)
      • • Department of Medicine
      • • College of Natural Sciences
      Gwangju, Gwangju, South Korea
  • 2007–2010
    • Yeungnam University
      • College of Pharmacy
      Gyeongsan, Gyeongsangbuk-do, South Korea
  • 1998
    • Korea Advanced Institute of Science and Technology
      • Department of Biological Sciences
      Sŏul, Seoul, South Korea