Discovery Research Center

Suigen, South Korea

Discovery Research Center

Suigen, South Korea
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Kim J.H.,Konkuk University | Kim Y.C.,Discovery Research Center | Park B.,Keimyung University
Oncology Reports | Year: 2016

The tumor necrosis factor related apoptosis inducing ligand (TRAIL) is a potent anticancer agent possessing the ability to induce apoptosis in various cancer cells but not in non malignant cells. However, certain type of cancer cells are resistant to TRAIL induced apoptosis and some acquire resistance after the first treatment. So development of an agent that can reduce or avoid resistance in TRAIL induced apoptosis has garnered significant attention. The present study evaluated the anticancer potential of hispolon in TRAIL induced apoptosis and indicated hispolon can sensitize cancer cells to TRAIL. As the mechanism of action was examined, hispolon was found to activate caspase3, caspase8 and caspase9, while downregulating the expression of cell survival proteins such as cFLIP, Bcl2 and Bcl xL and upregulating the expression of Bax and truncated Bid. We also found hispolon induced death receptors in a non cell type specific manner. Upregulation of death receptors by hispolon was found to be p53-independent but linked to the induction of CAAT enhancer binding protein homologous protein (CHOP). Overall, hispolon was demonstrated to potentiate the apoptotic effects of TRAIL through downregulation of anti apoptotic proteins and upregulation of death receptors linked with CHOP and pERK elevation.


Kim B.,Keimyung University | Kim Y.C.,Discovery Research Center | Park B.,Keimyung University
International Journal of Oncology | Year: 2016

Expression of the CXC chemokine receptor-4 (CXCR4), a G protein-coupled receptor, and HER2, a receptor tyrosine kinase, strongly correlates with tumor progression and metastatic potential of breast cancer cells. We report the identification of pomolic acid (PA) as a novel regulator of HER2 and CXCR4 expression. We found that PA downregulated the expression of HER2 and CXCR4 in SKBR3 cells in a dose- and time-dependent manner. When investigated for the molecular mechanism(s), it was found that the downregulation of HER2 and CXCR4 was not due to proteolytic degradation but rather to transcriptional regulation as indicated by downregulation of mRNA expression. Moreover, we show that PA inhibits phosphorylation of ERK and reduces NF-B activation. Suppression of CXCR4 expression by PA correlated with the inhibition of CXCL12-induced invasion of HER2-overexpressing breast cancer cells. Overall, our results demonstrate for the first time that PA is a novel inhibitor of HER2 and CXCR4 expression via kinase pathways and may play a critical role in determining the metastatic potential of breast cancer cells.


PubMed | Keimyung University and Discovery Research Center
Type: Journal Article | Journal: International journal of oncology | Year: 2016

Expression of the CXC chemokine receptor-4 (CXCR4), a G protein-coupled receptor, and HER2, a receptor tyrosine kinase, strongly correlates with tumor progression and metastatic potential of breast cancer cells. We report the identification of pomolic acid (PA) as a novel regulator of HER2 and CXCR4 expression. We found that PA downregulated the expression of HER2 and CXCR4 in SKBR3 cells in a dose- and time-dependent manner. When investigated for the molecular mechanism(s), it was found that the downregulation of HER2 and CXCR4 was not due to proteolytic degradation but rather to transcriptional regulation as indicated by downregulation of mRNA expression. Moreover, we show that PA inhibits phosphorylation of ERK and reduces NF-B activation. Suppression of CXCR4 expression by PA correlated with the inhibition of CXCL12-induced invasion of HER2-overexpressing breast cancer cells. Overall, our results demonstrate for the first time that PA is a novel inhibitor of HER2 and CXCR4 expression via kinase pathways and may play a critical role in determining the metastatic potential of breast cancer cells.


PubMed | Keimyung University, Discovery Research Center and Konkuk University
Type: Journal Article | Journal: Oncology reports | Year: 2016

The tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a potent anticancer agent possessing the ability to induce apoptosis in various cancer cells but not in nonmalignant cells. However, certain type of cancer cells are resistant to TRAILinduced apoptosis and some acquire resistance after the first treatment. So development of an agent that can reduce or avoid resistance in TRAILinduced apoptosis has garnered significant attention. The present study evaluated the anticancer potential of hispolon in TRAILinduced apoptosis and indicated hispolon can sensitize cancer cells to TRAIL. As the mechanism of action was examined, hispolon was found to activate caspase3, caspase8 and caspase9, while downregulating the expression of cell survival proteins such as cFLIP, Bcl2 and BclxL and upregulating the expression of Bax and truncated Bid. We also found hispolon induced death receptors in a noncell typespecific manner. Upregulation of death receptors by hispolon was found to be p53-independent but linked to the induction of CAAT enhancer binding protein homologous protein (CHOP). Overall, hispolon was demonstrated to potentiate the apoptotic effects of TRAIL through downregulation of antiapoptotic proteins and upregulation of death receptors linked with CHOP and pERK elevation.


Rikimaru K.,Takeda Pharmaceutical | Rikimaru K.,Medicinal Chemistry Research Laboratories | Wakabayashi T.,Takeda Pharmaceutical | Wakabayashi T.,Medicinal Chemistry Research Laboratories | And 38 more authors.
Bioorganic and Medicinal Chemistry | Year: 2012

Herein, we describe the design, synthesis, and structure-activity relationships of novel benzylpyrazole acylsulfonamides as non-thiazolidinedione (TZD), non-carboxylic-acid-based peroxisome proliferator-activated receptor (PPAR) γ agonists. Docking model analysis of in-house weak agonist 2 bound to the reported PPARγ ligand binding domain suggested that modification of the carboxylic acid of 2 would help strengthen the interaction of 2 with the TZD pocket and afford non-carboxylic-acid-based agonists. In this study, we used an acylsulfonamide group as the ring-opening analog of TZD as an isosteric replacement of carboxylic acid moiety of 2; further, preliminary modification of the terminal alkyl chain on the sulfonyl group gave the lead compound 3c. Subsequent optimization of the resulting compound gave the potent agonists 25c, 30b, and 30c with high metabolic stability and significant antidiabetic activity. Further, we have described the difference in binding mode of the carboxylic-acid-based agonist 1 and acylsulfonamide 3d. © 2011 Elsevier Ltd. All rights reserved.


Han S.Y.,Dongguk University | You B.H.,Dongguk University | Kim Y.C.,Discovery Research Center | Chin Y.-W.,Dongguk University | Choi Y.H.,Dongguk University
PLoS ONE | Year: 2015

The information about a marker compound's pharmacokinetics in herbal products including the characteristics of absorption, distribution, metabolism, excretion (ADME) is closely related to the efficacy/toxicity. Also dose range and administration route are critical factors to determine the ADME profiles. Since the supply of a sufficient amount of a marker compound in in vivo study is still difficult, pharmacokinetic investigations which overcome the limit of blood collection in mice are desirable. Thus, we have attempted to investigate concurrently the ADME and proposed metabolite identification of α-mangostin, a major constituent of mangosteen, Garcinia mangostana L, in mice with a wide dose range using an in vitro as well as in vivo automated micro-sampling system together. α-mangostin showed dose-proportional pharmacokinetics at intravenous doses of 5-20 mg/kg and oral doses of 10-100 mg/kg. The gastrointestinal absorption of α-mangostin was poor and the distribution of α-mangostin was relatively high in the liver, intestine, kidney, fat, and lung. α-mangostin was extensively metabolized in the liver and intestine. With regards to the formation of metabolites, the glucuronidated, bis-glucuronidated, dehydrogenated, hydrogenated, oxidized, and methylated α-mangostins were tentatively identified. We suggest that these dose-independent pharmacokinetic characteristics of α-mangostin in mice provide an important basis for preclinical applications of α-mangostin as well as mangosteen. In addition, these experimental methods can be applied to evaluate the pharmacokinetics of natural products in mice. © 2015 Han et al.


Choi M.R.,Catholic University of Korea | Kwon M.H.,Catholic University of Korea | Cho Y.Y.,Catholic University of Korea | Choi H.D.,Dongguk University | And 2 more authors.
Biopharmaceutics and Drug Disposition | Year: 2014

Under hyperlipidemic conditions, there are likely to be alterations in the pharmacokinetics of CYP2C11 substrates following decreased expression of CYP2C11, which is homologous to human CYP2C9. The pharmacokinetics of tolbutamide (TB) and its metabolite 4-hydroxy tolbutamide (4-OHTB) were evaluated as a CYP2C11 probe after intravenous and oral administration of 10 mg/kg tolbutamide to poloxamer 407-induced hyperlipidemic rats (HL rats). Changes in the expression and metabolic activity of hepatic CYP2C11 and the plasma protein binding of tolbutamide in HL rats were also evaluated. The total area under the plasma concentration-time curve (AUC) of tolbutamide in HL rats after intravenous administration was comparable to that in controls due to their comparable non-renal clearance (CLNR). The free fractions of tolbutamide in plasma were comparable between the control and HL rats. The 4-hydroxylated metabolite formation ratio (AUC4-OHTB/AUC TB) in HL rats was significantly smaller than that in the control rats as a result of the reduced expression of hepatic CYP2C11 (by 15.0%) and decreased hepatic CLint (by 28.8%) for metabolism of tolbutamide to 4-OHTB via CYP2C11. Similar pharmacokinetic changes were observed in HL rats after oral administration of tolbutamide. These findings have potential therapeutic implications, assuming that the HL rat model qualitatively reflects similar changes in patients with hyperlipidemia. Since other sulfonylureas in clinical use are substrates of CYP2C9, their hepatic CLint changes have the potential to cause clinically relevant pharmacokinetic changes in a hyperlipidemic state. Copyright © 2014 John Wiley & Sons, Ltd.


Ahn S.O.,Discovery Research Center | Ohtomo S.,Chugai Pharmaceutical Co. | Kiyokawa J.,Chugai Pharmaceutical Co. | Nakagawa T.,Chugai Pharmaceutical Co. | And 7 more authors.
Journal of Pharmacology and Experimental Therapeutics | Year: 2016

Urate-lowering therapy is indispensable for the treatment of gout, but available drugs do not control serum urate levels tightly enough. Although the uricosurics benzbromarone and probenecid inhibit a urate reabsorption transporter known as renal urate transporter 1 (URAT1) and thus lower serum urate levels, they also inhibit other transporters responsible for secretion of urate into urine, which suggests that inhibiting URAT1 selectively would lower serum urate more effectively. We identified a novel potent and selective URAT1 inhibitor, UR-1102, and compared its efficacy with benzbromarone in vitro and in vivo. In human embryonic kidney (HEK)293 cells overexpressing URAT1, organic anion transporter 1(OAT1), and OAT3, benzbromarone inhibited all transporters similarly, whereas UR-1102 inhibited URAT1 comparably to benzbromarone but inhibited OAT1 and OAT3 quite modestly. UR-1102 at 3-30 mg/kg or benzbromarone at 3-100 mg/kg was administered orally once a day for 3 consecutive days to tufted capuchin monkeys, whose low uricase activity causes a high plasma urate level. When compared with the same dosage of benzbromarone, UR-1102 showed a better pharmacokinetic profile, increased the fractional excretion of urinary uric acid, and reduced plasma uric acid more effectively. Moreover, the maximum efficacy of UR-1102 was twice that of benzbromarone, suggesting that selective inhibition of URAT1 is effective. Additionally UR-1102 showed lower in vitro potential for mechanisms causing the hepatotoxicity induced by benzbromarone. These results indicate that UR-1102 achieves strong uricosuric effects by selectively inhibiting URAT1 over OAT1 and OAT3 in monkeys, and could be a novel therapeutic option for patients with gout or hyperuricemia. Copyright © 2016 by The American Society for Pharmacology and Experimental Therapeutics.


Kwon M.H.,Catholic University of Korea | Yoon J.N.,Catholic University of Korea | Baek Y.J.,Catholic University of Korea | Kim Y.C.,Discovery Research Center | And 2 more authors.
Biopharmaceutics and Drug Disposition | Year: 2016

Hepatic multidrug resistance-associated protein 2 (Mrp2) is responsible for the majority of the biliary elimination of endogenous and exogenous substances, therefore it is important to evaluate possible functional changes in Mrp2 activity under conditions of hyperlipidemia (HL). Thus, the present study assessed the protein expression and transporting activity of hepatic Mrp2 based on the in vivo biliary excretion of phenolsulfonphthalein (PSP) as a model anionic substrate for Mrp2 in poloxamer 407-induced hyperlipidemic rats (HL rats) and compared these values with those for control rats. The pharmacokinetics of mycophenolic acid (MPA) and mycophenolic acid-7-O-glucuronide (MPAG) were evaluated after the intravenous (5 mg/kg) and oral (10 mg/kg) administration of MPA to control and HL rats. In HL rats, the protein expression of hepatic Mrp2 and its biliary transporting activity exhibited significant reductions (by 24.3% and 24.6%, respectively) in the absence of a change in bile flow rate. Unexpectedly, HL and control rats showed comparable biliary excretion rates of MPAG due to the counter effects of the reduced expression and activity of Mrp2 and a 484% increase in the free fraction of MPAG in HL rats. The estimated biliary clearance value of free MPAG in HL rats was considerably slower (by 77.1%) than that in control rats. Although significant pharmacokinetic changes in total MPA and MPAG levels were not observed in HL rats, there was a marked increase in free MPA and MPAG levels. Clinically relevant pharmacokinetic changes in subjects with HL that are related to MRP2 could not be ruled out. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.


PubMed | Discovery Research Center and Catholic University of Korea
Type: Journal Article | Journal: Biopharmaceutics & drug disposition | Year: 2016

Hepatic multidrug resistance-associated protein 2 (Mrp2) is responsible for the majority of the biliary elimination of endogenous and exogenous substances, therefore it is important to evaluate possible functional changes in Mrp2 activity under conditions of hyperlipidemia (HL). Thus, the present study assessed the protein expression and transporting activity of hepatic Mrp2 based on the in vivo biliary excretion of phenolsulfonphthalein (PSP) as a model anionic substrate for Mrp2 in poloxamer 407-induced hyperlipidemic rats (HL rats) and compared these values with those for control rats. The pharmacokinetics of mycophenolic acid (MPA) and mycophenolic acid-7-O-glucuronide (MPAG) were evaluated after the intravenous (5 mg/kg) and oral (10 mg/kg) administration of MPA to control and HL rats. In HL rats, the protein expression of hepatic Mrp2 and its biliary transporting activity exhibited significant reductions (by 24.3% and 24.6%, respectively) in the absence of a change in bile flow rate. Unexpectedly, HL and control rats showed comparable biliary excretion rates of MPAG due to the counter effects of the reduced expression and activity of Mrp2 and a 484% increase in the free fraction of MPAG in HL rats. The estimated biliary clearance value of free MPAG in HL rats was considerably slower (by 77.1%) than that in control rats. Although significant pharmacokinetic changes in total MPA and MPAG levels were not observed in HL rats, there was a marked increase in free MPA and MPAG levels. Clinically relevant pharmacokinetic changes in subjects with HL that are related to MRP2 could not be ruled out. Copyright 2016 John Wiley & Sons, Ltd.

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