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ABSTRACT: Iridoids belong to a group of monoterpene compounds with cyclopentane ring and found as mostly the glycoside forms in nature. They act primarily as the defense substances and found in various medicinal plants.
Although many iridoids exhibit anti-inflammatory and anticancer activities, their molecular targets/pathways are not fully understood. Here, the antiproliferative effect of the hydrolyzed-iridoid product (H-iridoid) form through the STAT3 signaling pathways on tumor cells was investigated.
H-iridoids were obtained from five iridoid glycosides with β-glucosidase treatment. The effects of several H-iridoids on cell viability and cell proliferation in tumor cells were measured by the MTT assay. The phosphorylation levels of STAT3, its regulatory molecules, and apoptosis by H-geniposide treatment in DU145 cells were investigated by immunoblots and flow cytometry. Results: No single iridoid glycoside exerted any cytotoxicity in the tumor cells, whereas H-iridoids had significant cytotoxic, antiproliferative, and STAT3 inhibitory effects and revealed different potencies depending on their chemical structures. Among the H-iridoids tested, H-geniposide inhibited constitutive STAT3 activation through inhibiting upstream JAK1 and c-Src. Consistent with STAT3 inactivation, H-geniposide downregulated the expressions of Bcl-2, Bcl-xL, survivin, and cyclin D1; this correlated with the accumulation of cells in the sub-G1 phase of the cell cycle and the induction of apoptosis.
Our results indicate that the hydrolysis of the glycosidic bond from iridoid glycoside is required for exhibiting cytotoxicity in tumor cells. H-geniposide is the most potent agent and a novel blocker of STAT3 activation in DU145 cells.
Pharmaceutical Biology 12/2011; 50(1):8-17. · 0.88 Impact Factor
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ABSTRACT: The aim of this prospective randomized clinical trial was to investigate the efficacy of a home-based program of isometric strengthening exercises for the treatment of the lateral epicondylitis (LE) of the distal humerus. We hypothesized that 1) use of isometric strengthening exercises would result in clinical benefits similar to those provided by medication and pain relief and 2) functional improvements after exercise would be time-dependent.
Patients were assigned to one of two groups: 1) an immediate physical therapy group (group I), or 2) a delayed physical therapy group (group D). Group I patients (n = 16) were instructed how to do the exercises at their first clinic visit and immediately carried out the exercise program. Group D patients (n = 15) learned and did the exercises after being on medications for 4 weeks.
Outcomes at the 1-month clinic visit indicated that pain (measured using a visual analogue scale [VAS]) had been significantly reduced in group I compared to group D (p < 0.01). However, significant differences between groups were not found at 3-, 6-, and 12-month follow-up for either VAS scores or Mayo elbow performance scores. For modified Nirschl/Pettrone scores, a significant difference between groups was found only at the 1-month follow-up visit. By then, the number of participants who returned to all activities with no pain or occasional mild pain was six (37%) in Group I and two (13%) in Group D (p = 0.031). At the final follow-up visit, 88% of all participants performed physical activities without pain.
Isometric strengthening exercises done early in the course of LE (within 4 weeks) provides a clinically significant improvement.
Clinics in orthopedic surgery 09/2010; 2(3):173-8.
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Young-Hyun Han,
Marie-Line Garron,
Hye-Yeon Kim, Wan-Seok Kim,
Zhenqing Zhang,
Kyeong-Seok Ryu,
David Shaya,
Zhongping Xiao,
Chaejoon Cheong,
Yeong Shik Kim,
Robert J Linhardt,
Young Ho Jeon,
Miroslaw Cygler
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ABSTRACT: Heparin lyase I (heparinase I) specifically depolymerizes heparin, cleaving the glycosidic linkage next to iduronic acid. Here, we show the crystal structures of heparinase I from Bacteroides thetaiotaomicron at various stages of the reaction with heparin oligosaccharides before and just after cleavage and product disaccharide. The heparinase I structure is comprised of a beta-jellyroll domain harboring a long and deep substrate binding groove and an unusual thumb-resembling extension. This thumb, decorated with many basic residues, is of particular importance in activity especially on short heparin oligosaccharides. Unexpected structural similarity of the active site to that of heparinase II with an (alpha/alpha)(6) fold is observed. Mutational studies and kinetic analysis of this enzyme provide insights into the catalytic mechanism, the substrate recognition, and processivity.
Journal of Biological Chemistry 10/2009; 284(49):34019-27. · 4.77 Impact Factor
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ABSTRACT: We analysed the dynamic change of imatinib-resistant mutations in BCR-ABL kinase domain focusing on T315I mutation during dasatinib or nilotinib therapy. Fifty-five imatinib-resistant chronic myeloid leukaemia patients (32 patients with imatinib-resistant mutations and 23 patients without mutation) in different disease phases were treated with dasatinib (median 17.3 months) or nilotinib (median 6.8 months). Among the 32 patients with baseline mutation, mutations including M244V, G250E, E255K, M351T, H396R, S417Y, E450K and E459K disappeared in 8 patients and new mutations were detected in 9 patients, all of which were T315I. Among the 23 patients without baseline mutation, 4 patients showed newly developed mutations including T315I, T315I + E459K, M244V and F359V. The T315I was the most frequently detected mutation in imatinib therapy (16%, 9 of 55) as well as in dasatinib or nilotinib therapy (24%, 11 of 44). Patients with imatinib resistant baseline mutations had a higher rate of mutation development during dasatinib or nilotinib treatment compared to patients without baseline mutations (28% vs. 17%).
Hematological Oncology 09/2009; 28(2):82-8. · 2.47 Impact Factor
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Hyun-Gyung Goh,
Yoo-Jin Kim,
Dong-Wook Kim,
Hyeoung-Joon Kim,
Soo-Hyun Kim,
Se-Eun Jang,
Jeong Lee,
Dongho Kim, Wan-Seok Kim,
Sa-Hee Park,
Il-Young Kweon
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ABSTRACT: Although imatinib is considered as a front line therapy in patients with chronic myeloid leukemia (CML), it is still unclear whether transient imatinib discontinuation may adversely affect the outcome. This study was conducted to investigate long-term outcome after discontinuation and resumption of imatinib, and to determine whether intermittent imatinib therapy can be employed in patients with CML. Twenty six Philadelphia chromosome positive (Ph+) patients with CML discontinued imatinib when they achieved complete cytogenetic response (CCyR) or complete molecular response (CMR), and they were retreated with imatinib in case of hematologic, cytogenetic or molecular relapse. Except one patient who progressed and two patients who are in persistent molecular remission without imatinib resumption, all of 23 patients are maintaining the best response achieved after imatinib resumption with a median follow-up of 44 months. This study shows that although imatinib cannot be discontinued completely, intermittent therapy can be considered for the treatment of patients with CML in particular situations.
Leukemia & lymphoma 07/2009; 50(6):944-51. · 2.40 Impact Factor
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Jung-Hoon Lee,
Hyo-Jeong Lee,
Chan-Hee Lee,
Hyo-Jung Lee,
Hyunsoo Bae,
Sung-Moo Kim,
Sun-Hee Kim,
Wonil Koh, Wan-Seok Kim,
Kwang Seok Ahn,
Seung-Hoon Choi,
Namin Baek,
Sung-Hoon Kim
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ABSTRACT: Hwaeumjeon is a classical prescription that has been traditionally used for treatment of urogenital diseases with no scientific evidences until now. Thus, the present study was performed to evaluate antitumor mechanism of ethanolic Hwaeumjeon (EHEJ). 2-Dimensional electrophoresis (2-DE) proteomic analysis, cell culture study, and Western blotting on apoptosis and prostate-specific antigen (PSA) related proteins were carried out in LNCaP prostate cancer cells. Eight spots with significant increased or decreased expression revealed by 2-DE based comparative proteomic analysis were identified as an increased protein ENC-1AS, four decreased proteins such as RAB34, SFRS1, heat shock 27, and proteasome activator, and three novel proteins such as Rho GDP dissociation inhibitor alpha, cytoplasmic antiproteinase, and EIF3EIP protein in EHEJ-treated LNCaP cells. In addition, EHEJ selectively inhibited the growth of LNCaP prostate cancer cells compared to normal human umbilical vein endothelial cells. Furthermore, EHEJ inhibited PSA and androgen receptor (AR) expression in androgen sensitive LNCaP prostate cancer cells at nontoxic concentrations. Also, EHEJ increased sub-G1 apoptotic portion, activated caspase-9 and -3, cleaved poly (ADP-ribose) polymerase (PARP) and increased the ratio of Bax to Bcl-2. Interestingly, EHEJ also attenuated phosphatidylinositol-3 kinase (PI3K) expression and suppressed the phosphorylation of survival gene AKT, ERK, and HSP27 in LNCaP cells. Consistently, PI3K and ERK inhibitors potentiated EHEJ-induced cytotoxicity and overexpression of Bcl-2 attenuated EHEJ-mediated apoptosis in LNCaP cells. These findings suggest that EHEJ induces mitochondrial dependent apoptosis partly via PI3K/AKT/HSP27/ERK pathways and inhibits PSA and AR in LNCaP cells as a prostate cancer chemopreventive candidate.
Environmental Toxicology and Pharmacology 07/2009; 28(1):78-85. · 1.47 Impact Factor
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Dong-Wook Kim,
Yeow-Tee Goh,
Hui-Hua Hsiao,
Priscilla B Caguioa,
Dongho Kim, Wan-Seok Kim,
Tapan Saikia,
Shruti Agrawal,
Amit Roy,
David Dai,
M Brigid Bradley-Garelik,
Jaydip Mukhopadhyay,
Saengsuree Jootar
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ABSTRACT: Resistance and intolerance to imatinib are of particular clinical relevance to Asian patients because of their lower body surface area. Dasatinib is 325-fold more potent than imatinib in inhibiting BCR-ABL in vitro and is indicated for the treatment of chronic myeloid leukemia (CML) and Philadelphia chromosome-positive acute lymphoblastic leukemia resistant or intolerant to imatinib. Data from a series of phase I/II research trials were analyzed to compare the efficacy, safety and pharmacokinetic profile of dasatinib 70 mg twice daily in Asian and non-Asian patients. Results from 55 Asian and 615 non-Asian patients demonstrated that the efficacy and safety of dasatinib was comparable. Dasatinib was well tolerated, with no observed toxicities exclusive to Asian patients. A higher incidence of adverse events and lower rate of response observed among Asian patients with myeloid blast phase CML reflected the aggressive nature of the disease. Analyses of noncompartmental pharmacokinetics (5 Asian and 49 non-Asian patients) and population pharmacokinetics (17 Asian and 382 non-Asian patients) were also comparable. The efficacy, safety and pharmacokinetic profile of dasatinib 70 mg twice daily is similar in Asian and non-Asian patients with CML. Dasatinib is therefore an important therapeutic option for this patient population.
International journal of hematology 06/2009; 89(5):664-72. · 1.17 Impact Factor
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ABSTRACT: The inhibitory effects of green tea polyphenol epigallocatechin gallate (EGCG) on virulence phenotypes and gene expression regulated by quorum sensing (QS) in Escherichia coli O157:H7 were demonstrated at concentrations of 1 to 100 microg/ml, which are lower than the MIC (539 +/- 22 microg/ml). At 25 microg/ml, the growth rate was not affected, but autoinducer 2 concentration, biofilm formation, and swarm motility decreased to 13.2, 11.8, and 50%, respectively. Survival at 5 days of nematodes (Caenorhabditis elegans) that were fed the pathogen without and with EGCG were 47.1 and 76%, respectively. Real-time PCR data indicated decreased transcriptional level in many quorum sensing-regulated virulence genes at 25 microg/ml. Our results suggest that EGCG at concentrations below itsMIC has significant antipathogenic effects against E. coli O157:H7.
Journal of food protection 03/2009; 72(2):325-31. · 1.94 Impact Factor
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Dongho Kim,
Dong-Wook Kim,
Byung-Sik Cho,
Hyun-Gyung Goh,
Soo-Hyun Kim, Wan-Seok Kim,
Jeong Lee,
Il-Young Kweon,
Sa-Hee Park,
Jeong Hyeok Yoon,
Nam Doo Kim,
Haarin Chun
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ABSTRACT: Sequential treatment with different tyrosine kinase inhibitors (TKIs) is one of the strategies for handling chronic myeloid leukemia (CML) in which dynamic change in Bcr-Abl kinase domain mutation is often an obstacle faced during TKI therapy. Here we report successful sequential therapy with different TKIs for the CML patient harboring V299L and E459K compound mutations. Molecular monitoring including quantitative analysis of BCR-ABL transcript level and mutation analysis were performed regularly for successful treatment. Additionally a drug-target complex was structurally modeled to investigate influence of amino acid substitutions on drug resistance, and to choose alternative TKI in sequential therapy, suggesting protein structural modeling can be useful approach in selecting alternative TKIs.
Leukemia research 03/2009; 33(9):1260-5. · 2.36 Impact Factor
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ABSTRACT: Despite durable responses to imatinib in chronic myeloid leukaemia (CML), mutations in Bcr-Abl kinase domain (KD) are known to induce imatinib resistance and cause poor clinical outcome. We characterized Bcr-Abl KD mutations in 137 Korean CML patients with imatinib resistance (n = 111) or intolerance (n = 26) using allele specific oligonucleotide polymerase chain reaction (PCR) and direct sequencing. Seventy (51%) patients harboured 81 mutations of 20 different types with increasing prevalence in advanced phase. Nine (13%) patients had multiple mutations. No mutation was found in intolerant patients. T315I was the most common mutation and P-loop was the hottest spot in Bcr-Abl KD. Patients harbouring P-loop mutation, T315I, or multiple mutations showed poor overall survival and progression free survival compared with patients harbouring other mutations. Survival analysis according to disease phase of mutation being detected and type of mutations provided correlation between P-loop or T315I mutation and poor overall survival in blast crisis, but not in accelerated phase (AP) or chronic phase (CP), indicating poor clinical outcome of particular mutations depends on disease phase. CML patients with imatinib resistance showed high rate (63%) of mutations in Bcr-Abl KD and therefore CML patients who do not respond to imatinib should be the candidates for mutation screening as molecular monitoring.
Hematological Oncology 03/2009; 27(4):190-7. · 2.47 Impact Factor
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ABSTRACT: Enzymes have evolved as catalysts with high degrees of stereospecificity. When both enantiomers are biologically important, enzymes with two different folds usually catalyze reactions with the individual enantiomers. In rare cases a single enzyme can process both enantiomers efficiently, but no molecular basis for such catalysis has been established. The family of bacterial chondroitin lyases ABC comprises such enzymes. They can degrade both chondroitin sulfate (CS) and dermatan sulfate (DS) glycosaminoglycans at the nonreducing end of either glucuronic acid (CS) or its epimer iduronic acid (DS) by a beta-elimination mechanism, which commences with the removal of the C-5 proton from the uronic acid. Two other structural folds evolved to perform these reactions in an epimer-specific fashion: (alpha/alpha)(5) for CS (chondroitin lyases AC) and beta-helix for DS (chondroitin lyases B); their catalytic mechanisms have been established at the molecular level. The structure of chondroitinase ABC from Proteus vulgaris showed surprising similarity to chondroitinase AC, including the presence of a Tyr-His-Glu-Arg catalytic tetrad, which provided a possible mechanism for CS degradation but not for DS degradation. We determined the structure of a distantly related Bacteroides thetaiotaomicron chondroitinase ABC to identify additional structurally conserved residues potentially involved in catalysis. We found a conserved cluster located approximately 12 A from the catalytic tetrad. We demonstrate that a histidine in this cluster is essential for catalysis of DS but not CS. The enzyme utilizes a single substrate-binding site while having two partially overlapping active sites catalyzing the respective reactions. The spatial separation of the two sets of residues suggests a substrate-induced conformational change that brings all catalytically essential residues close together.
Glycobiology 04/2008; 18(3):270-7. · 3.58 Impact Factor
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Soo Jae Lee,
Kyun-Hwan Kim,
Ji Sook Park,
Jin Woo Jung,
Young Hwan Kim,
Sang Kyung Kim, Wan-Seok Kim,
Hyun-gyung Goh,
Soo-hyun Kim,
Jung-Sun Yoo,
Dong-Wook Kim,
Kwang Pyo Kim
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ABSTRACT: This study was designed to identify the cell surface protein markers that can differentiate between chronic myeloid leukemia (CML) and acute promyelocytic leukemia cells (APL). The differentially expressed plasma membrane proteins were analyzed between CML cell line (K562) and APL cell line (NB4) using the comparative proteomic approach. The cell membrane proteins were enriched by labeling with a membrane-impermeable biotinylation reagent, sulfo-NHS-SS-Biotin, and subjected to liquid chromatography tandem mass spectrometry (LC-MS/MS). By comparative proteomic analysis of K562 and NB4 cells, we identified 25 membrane and 14 membrane-associated proteins. The result of LC-MS/MS combined with chemical tagging method was validated by confirming the expression and localization of one of the differentially expressed plasma membrane proteins, CD43, by FACS and confocal microscopy. Our results indicate that CD43 could be a potential candidate for differentiating CML from APL.
Biochemical and Biophysical Research Communications 07/2007; 357(3):620-6. · 2.48 Impact Factor
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ABSTRACT: Heparin lyase I was purified to homogeneity from Bacteroides stercoris HJ-15 isolated from human intestine, by a combination of DEAE-Sepharose, gel-filtration, hydroxyapatite, and CM-Sephadex C-50 column chromatography. This enzyme preferred heparin to heparan sulfate, but was inactive at cleaving acharan sulfate. The apparent molecular mass of heparin lyase I was estimated as 48,000 daltons by SDS-PAGE and its isoelectric point was determined as 9.0 by IEF. The purified enzyme required 500 mM NaCl in the reaction mixture for maximal activity and the optimal activity was obtained at pH 7.0 and 50 degrees C. It was rather stable within the range of 25 to 50 degrees C but lost activity rapidly above 50 degrees C. The enzyme was activated by Co(2+) or EDTA and stabilized by dithiothreitol. The kinetic constants, K(m) and V(max) for heparin were 1.3 10(-5) M and 8.8 micromol/min.mg. The purified heparin lyase I was an eliminase that acted best on porcine intestinal heparin, and to a lesser extent on porcine intestinal mucosa heparan sulfate. It was inactive in the cleavage of N-desulfated heparin and acharan sulfate. In conclusion, heparin lyase I from Bacteroides stercoris was specific to heparin rather than heparan sulfate and its biochemical properties showed a substrate specificity similar to that of Flavobacterial heparin lyase I.
Journal of biochemistry and molecular biology 12/2004; 37(6):684-90. · 2.02 Impact Factor
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ABSTRACT: Glycosaminoglycans were isolated from the eel skin (Anguilla japonica) by actinase and endonuclease digestions, followed by a beta-elimination reaction and DEAE-Sephacel chromatography. Dermatan sulfate was the major glycosaminoglycan in the eel skin with 88% of the total uronic acid. The content of the IdoA2Salpha1-->4GalNAc4S sequence in eel skin, which shows anticoagulant activity through binding to heparin cofactor II, was two times higher than that of dermatan sulfate from porcine skin. The anti-IIa activity of eel skin dermatan sulfate was determined to be 2.4 units/mg, whereas dermatan sulfate from porcine skin shows 23.2 units/mg. The average molecular weight of dermatan sulfate was determined by gel chromatography on a TSKgel G3000SWXL column as 14 kDa. Based on 1H NMR spectroscopy, the presence of 3-sulfated and/or 2,3-sulfated IdoA residues was suggested. The reason why highly sulfated dermatan sulfate does not show anticoagulant activity is discussed. In addition to dermatan sulfate, the eel skin contained a small amount of keratan sulfate, which was identified by keratanase treatment.
Carbohydrate Research 01/2003; 338(3):263-9. · 2.33 Impact Factor
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ABSTRACT: Two novel acharan sulfate lyases (ASL1 and ASL2: no EC number) have been purified from Bacteroides stercoris HJ-15 which was isolated from human intestinal bacteria with glycosaminoglycan (GAG) degrading enzymes. These enzymes were purified to apparent homogeneity by a combination of QAE-cellulose, DEAE-cellulose, carboxymethyl–Sephadex C-50, hydroxyapatite and HiTrap SP Sephadex C-25 column chromatography with the final specific activity of 50.5 and 76.7 µmol·min−1·mg−1, respectively. Both acharan sulfate lyases are single subunits of 83 kDa by SDS/PAGE and gel filtration. ASL1 showed optimal activity at pH 7.2 and 45 °C. ASL1 activity was inhibited by Cu2+, Ni2+ and Co2+, but ASL2 activity was inhibited by Cu2+, Ni2+and Pb2. Both enzymes were slightly inhibited by some agents that modify histidine and cysteine residues, but activated by reducing agents such as dl-dithiothreitol and 2-mercaptoethanol. Both purified bacteroidal acharan sulfate lyases acted to the greatest extent on acharan sulfate, and to a lesser extents on heparan sulfate and heparin. They did not act on de-O-sulfated acharan sulfate. These findings suggest that the biochemical properties of these purified acharan sulfate lyases are different from those of the previously purified heparin lyases, but these enzymes belong to heparinase II.
European Journal of Biochemistry. 12/2001; 268(9):2635 - 2641.
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ABSTRACT: The gene of capillary permeability-increasing enzyme-2 (CPI enzyme-2) was cloned from the cDNA library of Agkistrodon caliginosus and its nucleotide sequence was determined. Its sequence indicates that CPI enzyme-2 is synthesized as a pre-zymogen of 258 amino acid residues, including a putative secretory signal peptide of 18 amino acids and a proposed zymogen peptide of 6 amino acids. The amino terminal sequence deduced from the cDNA sequence was exactly consistent with that of CPI enzyme-2 except for the substitution of an amino acid (Gly27→Ser). The open reading frame is very similar to those of plasminogen activator and thrombin-like proteases cloned from other snakes. The clone encoding CPI enzyme-2 belongs to the serine protease family. The active site of the enzyme is highly conserved at His41, Asp86 and Ser180. Its possible glycosylation sites, Asn–X–Thr/Ser, are located at amino acid residues 20–22, 55–57, 79–81 and 97–99.
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