Browsing by Author "Chao, Yu-Sheng"

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A High-throughput Cell-based Screening for L858R/T790M Mutant Epidermal Growth Factor Receptor Inhibitors
(2012-01-01)
Lin, Wen-Hsing
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Song, Jen-Shin
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Lien, Tzu-Wen
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Chang, Chun-Yu
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Wu, Szu-Huei
A high-throughput 32D(L858R/T790M) cell-based assay to identify inhibitors of the L858R/T790M mutant epidermal growth factor receptor (EGFR) pathway was established. After screening, ten hits from among 60,000 compounds in our in-house compound library were initially identified. In the secondary assays, one hit, 1-[2-(decyloxy)-2-oxoethyl]-3-methyl-2-[(4-methylphenoxy) methyl]-1H-benzimidazol-3-ium, was confirmed to directly inhibit the kinase activity of recombinant L858R/T790M EGFR and the phosphorylation of EGFR-L858R/T790M in gefitinib-resistant H1975 cells. Thus, this high-throughput assay system may be useful for identifying novel inhibitors which suppress mutant EGFR-T790M signalling and for overcoming T790M-mediated acquired resistance for future anticancer drug discovery.
Anti-influenza drug discovery
(2007-07-01)
Hsu, John T.-A.
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Hsieh, Hsing-Pang
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Hung, Hui-Chen
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Ju, Yi Wei
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Tseng, Sung-Nain
Anti-Influenza Drug Discovery: Structure-Activity Relationship and Mechanistic Insight into Novel Angelicin Derivatives
(2010-02-25)
Yeh, Jiann-Yih
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Coumar, Mohane Selvaraj
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Horng, Jim-Tong
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Shiao, Hui-Yi
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Kuo, Fu-Ming
By using a cell-based high throughput screening campaign,a novel angelicin derivative 6a was identified to inhibit influenza A (H1N1) virus induced Cytopathic effect in Madin-Darby canine kidney cell culture in low micromolar range. Detailed structure-activity relationship studies of 6a revealed that the angelicin scaffold is essential for activity in pharmacophore B, while meta-substituted phenyl/2-thiophene rings are optimal ill pharmacophore A and C. The optimized lead 4-methyl-9-phenyl-8-(thiophene-2-carbonyl)-furo[2,3-h]chromen-2-one (8g, IC(50) = 70 nM) showed 64-fold enhanced activity compared to the high throughput screening (HTS) hit 6a. Also, 8g was found effective in case of influenza A (H3N2) and influenza B virus strains similar to approved anti-influenza drug zanamivir (4). Preliminary mechanistic studies suggest that these compounds act as anti-influenza agents by inhibiting ribonucleoprotein (RNP) complex associated activity and have the potential to be developed further, Which Could form the basis for developing additional defense against influenza pandemics.
Aurintricarboxylic acid inhibits influenza virus neuraminidase
(2009-02-01)
Hung, Hui-Chen
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Tseng, Ching-Ping
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Yang, Jinn-Moon
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Ju, Yi-Wei
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Tseng, Sung-Nain
There is a continuing threat that the highly pathogenic avian influenza virus will cause future influenza pandemics. In this study, we screened a library of compounds that are biologically active and structurally diverse for inhibitory activity against influenza neuraminidase (NA). We found that aurintricarboxylic acid (ATA) is a potent inhibitor of NA activity of both group-1 and group-2 influenza viruses with IC(50)S (effective concentration to inhibit NA activity by 50%) values at low micromolar concentrations. ATA was equally potent in inhibiting the NA activity derived from wild-type NA and its H274Y mutant which renders NA resistance to inhibition by oseltamivir. Although ATA is structurally distinct from sialic acid, molecular modeling experiments suggested that ATA binds to NA at the enzyme's substrate binding site. These results indicate that ATA may be a good starting material for the design of a novel class of NA inhibitors for the treatment influenza viruses. (C) 2008 Elsevier B.V. All rights reserved.
BPR2-D2 targeting viral ribonucleoprotein complex-associated function inhibits oseltamivir-resistant influenza viruses
(2010-01-01)
Shih, Shin-Ru
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Horng, Jim-Tong
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Poon, Leo L. M.
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Chen, Tzu-Chun
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Yeh, Jiann-Yih
The emergence of oseltamivir-resistant viruses raised the global threat with regard to influenza virus infection. To develop alternative antiviral agents against influenza virus infection is significant and urgent. A neutralization test was applied as a screening assay and a plaque reduction assay was used for confirmation. Expression plasmids for viral ribonucleoproteins (RNPs) and a plasmid that allowed expression of a pseudoviral reporter RNA were transfected into cells to investigate the effects of a novel antiviral compound on viral RNA synthesis. BPR2-D2 was identified as a novel inhibitor against influenza virus from a hit obtained from high throughput screening of 20 000 or more compounds. BPR2-D2 exhibited an excellent antiviral efficacy for the oseltamivir-resistant virus (EC(50) ranging from 0.021 to 0.040 mu M). No resistant virus was produced throughout 20 passages in the presence of BPR2-D2, whereas oseltamivir-resistant virus was generated at passage 8 using the same experimental system. A molecular target other than neuraminidase (NA) was found because BPR2-D2 inhibited the synthesis of viral RNA that was driven by influenza viral RNP in a transfection assay. BPR2-D2 also exhibited a broad antiviral spectrum against various strains of influenza A and influenza B viruses. BPR2-D2 was identified as a novel inhibitor of influenza virus. It may target viral RNPs that are responsible for viral RNA synthesis. Targeting different molecules compared with NA allows BPR2-D2 to inhibit oseltamivir-resistant viruses.
Design and Structural Analysis of Novel Pharmacophores for Potent and Selective Peroxisome Proliferator-activated Receptor gamma Agonists
(2009-04-23)
Lin, Chia-Hui
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Peng, Yi-Hui
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Coumar, Mohane Selvaraj
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Chittimalla, Santhosh Kumar
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Liao, Chun-Chen
Utilizing medicinal chemistry design strategies Such as benzo splitting and ring expansion, we converted PPAR alpha/gamma dual agonist 1 to selective PPAR gamma agonists 19 and 20. Compounds 19 and 20 were 2- to 4-fold better than rosiglitazone at PPAR gamma receptor. with 80- to 100-fold PPAR gamma selectivity over PPAR alpha receptor. X-ray cocrystal studies in PPAR gamma and modeling studies in PPAR alpha give molecular insights for the improved PPAR gamma potency and selectivity for 19 when compared to 1.
Design and Synthesis of Tetrahydropyridothieno[2,3-d]pyrimidine Scaffold Based Epidermal Growth Factor Receptor (EGFR) Kinase Inhibitors: The Role of Side Chain Chirality and Michael Acceptor Group for Maximal Potency
(2010-10-28)
Wu, Chia-Hsien
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Coumar, Mohane Selvaraj
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Chu, Chang-Ying
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Lin, Wen-Hsing
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Chen, Yi-Rong
HTS hit 7 was modified through hybrid design strategy to introduce a chiral side chain followed by introduction of Michael acceptor group to obtain potent EGFR kinase inhibitors 11 and 19. Both 11 and 19 showed over 3 orders of magnitude enhanced HCC827 antiproliferative activity compared to HTS hit 7 and also inhibited gefitinib-resistant double mutant (DM, T790M/L858R) EGFR kinase at nanomolar concentration. Moreover, treatment with 19 shrinked tumor in nude mice xenograft model.
Design and Synthesis of Tetrahydropyridothieno[2,3-d]pyrimidine Scaffold Based Epidermal Growth Factor Receptor (EGFR) Kinase Inhibitors: The Role of Side Chain Chirality and Michael Acceptor Group for Maximal Potency
(2010-10-28)
Wu, Chia-Hsien
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Coumar, Mohane Selvaraj
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Chu, Chang-Ying
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Lin, Wen-Hsing
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Chen, Yi-Rong
HTS hit 7 was modified through hybrid design strategy to introduce a chiral side chain followed by introduction of Michael acceptor group to obtain potent EGFR kinase inhibitors 11 and 19. Both 11 and 19 showed over 3 orders of magnitude enhanced HCC827 antiproliferative activity compared to HTS hit 7 and also inhibited gefitinib-resistant double mutant (DM, T790M/L858R) EGFR kinase at nanomolar concentration. Moreover, treatment with 19 shrinked tumor in nude mice xenograft model.
Evaluation of the Antitumor Effects of BPR1J-340, a Potent and Selective FLT3 Inhibitor, Alone or in Combination with an HDAC Inhibitor, Vorinostat, in AML Cancer
(2014-01-08)
Lin, Wen-Hsing
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Yeh, Teng-Kuang
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Jiaang, Weir-Torn
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Yen, Kuei-Jung
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Chen, Chun-Hwa
Overexpression or/and activating mutation of FLT3 kinase play a major driving role in the pathogenesis of acute myeloid leukemia (AML). Hence, pharmacologic inhibitors of FLT3 are of therapeutic potential for AML treatment. In this study, BPR1J-340 was identified as a novel potent FLT3 inhibitor by biochemical kinase activity (IC50 approximately 25 nM) and cellular proliferation (GC(50) approximately 5 nM) assays. BPR1J-340 inhibited the phosphorylation of FLT3 and STAT5 and triggered apoptosis in FLT3-ITD+ AML cells. The pharmacokinetic parameters of BPR1J-340 in rats were determined. BPR1J-340 also demonstrated pronounced tumor growth inhibition and regression in FLT3-ITD+ AML murine xenograft models. The combination treatment of the HDAC inhibitor vorinostat (SAHA) with BPR1J-340 synergistically induced apoptosis via Mcl-1 down-regulation in MOLM-13 AML cells, indicating that the combination of selective FLT3 kinase inhibitors and HDAC inhibitors could exhibit clinical benefit in AML therapy. Our results suggest that BPR1J-340 may be further developed in the preclinical and clinical studies as therapeutics in AML treatments.
Fast-Forwarding Hit to Lead: Aurora and Epidermal Growth Factor Receptor Kinase Inhibitor Lead Identification
(2010-07-08)
Coumar, Mohane Selvaraj
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Chu, Chang-Ying
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Lin, Cheng-Wei
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Shiao, Hui-Yi
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Ho, Yun-Lung
A focused library of furanopyrimidine (350 compounds) was rapidly synthesized in parallel reactors and in situ screened for Aurora and epidermal growth factor receptor (EGFR) kinase activity, leading to the identification of some interesting hits. On the basis of structural biology observations, the hit la was modified to better fit the back pocket, producing the potent Aurora inhibitor 3 with submicromolar antiproliferative activity in HCT-116 colon cancer cell line. On the basis of docking studies with EGFR hit Is, introduction of acrylamide Michael acceptor group led to 8, which inhibited both the wild and mutant EGFR kinase and also showed antiproliferative activity in HCC827 lung cancer cell line. Furthermore, the X-ray cocrystal study of 3 and 8 in complex with Aurora and EGFR, respectively, confirmed their hypothesized binding modes. Library construction, in situ screening, and structure-based drug design (SBDD) strategy described here could be applied for the lead identification of other kinases.
Identification, SAR Studies, and X-ray Co-crystallographic Analysis of a Novel Furanopyrimidine Aurora Kinase A Inhibitor
(2010-02-01)
Coumar, Mohane Selvaraj
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Tsai, Ming-Tsung
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Chu, Chang-Ying
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Uang, Biing-Jiun
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Lin, Wen-Hsing
Here in we reveal a simple method for the identification of novel Aurora kinase A inhibitors through substructure searching of an in-house compounds for testing. A hydrazone fragment conferring Aurora kinase activity and heterocyclic rings most frequently reported in kinase inhibitors were used as substructure queries to filter the in house compound library collection prior to testing. Five new series of Aurora kinase inhibitors were identified through this strategy with IC(50) values ranging from similar to 300 nm to similar to 15 mu m, by testing only 133 compounds from a database of similar to 125 000 compounds. Structure activity relationship studies and X-ray co-crystallographic analysis of the most potent compound, a furanopyrimidine derivative with an IC(50) value of 309 nm toward Aurora kinase A, were carried out. The knowledge gained through these studies could help in the future design of potent Aurora kinase inhibitors.
Pyrazole compound BPR1P0034 with potent and selective anti-influenza virus activity
(2010-02-23)
Shih, Shin-Ru
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Chu, Tzu-Yun
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Reddy, Gadarla Randheer
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Tseng, Sung-Nain
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Chen, Hsiun-Ling
Background: Influenza viruses are a major cause of morbidity and mortality around the world. More recently, a swine-origin influenza A (H1N1) virus that is spreading via human-to-human transmission has become a serious public concern. Although vaccination is the primary strategy for preventing infections, influenza antiviral drugs play an important role in a comprehensive approach to controlling illness and transmission. In addition, a search for influenza-inhibiting drugs is particularly important in the face of high rate of emergence of influenza strains resistant to several existing influenza antivirals. Methods: We searched for novel anti-influenza inhibitors using a cell-based neutralization (inhibition of virus-induced cytopathic effect) assay. After screening 20,800 randomly selected compounds from a library from ChemDiv, Inc., we found that BPR1P0034 has sub-micromolar antiviral activity. The compound was resynthesized in five steps by conventional chemical techniques. Lead optimization and a structure-activity analysis were used to improve potency. Time-of-addition assay was performed to target an event in the virus life cycle. Results: The 50% effective inhibitory concentration (IC(50)) of BPR1P0034 was 0.42 +/- 0.11 mu M, when measured with a plaque reduction assay. Viral protein and RNA synthesis of A/WSN/33 (H1N1) was inhibited by BPR1P0034 and the virus-induced cytopathic effects were thus significantly reduced. BPR1P0034 exhibited broad inhibition spectrum for influenza viruses but showed no antiviral effect for enteroviruses and echovirus 9. In a time-of-addition assay, in which the compound was added at different stages along the viral replication cycle (such as at adsorption or after adsorption), its antiviral activity was more efficient in cells treated with the test compound between 0 and 2 h, right after viral infection, implying that an early step of viral replication might be the target of the compound. These results suggest that BPR1P0034 targets the virus during viral uncoating or viral RNA importation into the nucleus. Conclusions: To the best of our knowledge, BPR1P0034 is the first pyrazole-based anti-influenza compound ever identified and characterized from high throughput screening to show potent (sub-mu M) antiviral activity. We conclude that BPR1P0034 has potential antiviral activity, which offers an opportunity for the development of a new anti-influenza virus agent.
Structural Basis for the Improved Potency of Peroxisome Proliferator-Activated Receptor (PPAR) Agonists
(2010-10-04)
Peng, Yi-Hui
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Coumar, Mohane Selvaraj
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Leou, Jiun-Shyang
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Wu, Jian-Sung
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Shiao, Hui-Yi
The need to develop safer and more effective antidiabetic drugs is essential owing to the growth worldwide of the diabetic population. Targeting the PPAR receptor is one strategy for the treatment of diabetes; the PPAR agonists rosiglitazone and pioglitazone are already on the market. Here we report the identification of a potent PPAR agonist, 15, whose PPAR gamma activation was more than 20 times better than that of rosiglitazone. Compound 15 was designed to incorporate an indole head with a carboxylic acid group, and 4-phenylbenzophenone tail to achieve a PPAR gamma EC(50) of 10 nm. Compound 15 showed the most potent PPAR gamma agonist activity among the compounds we investigated. To gain molecular insight into the improved potency of 15, a structural biology study and binding energy calculations were carried out. Superimposition of the X-ray structures of 15 and agonist 10 revealed that, even though they have the same indole head part, they adopt different conformations. The head part of 15 showed stronger interactions toward PPAR gamma; this could be due to the presence of the novel tail part 4-phenylbenzophenone, which could enhance the binding efficiency of 15 to PPAR gamma.
Structural Basis for the Improved Potency of Peroxisome Proliferator-Activated Receptor (PPAR) Agonists
(2010-10-04)
Peng, Yi-Hui
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Coumar, Mohane Selvaraj
;
Leou, Jiun-Shyang
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Wu, Jian-Sung
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Shiao, Hui-Yi
The need to develop safer and more effective antidiabetic drugs is essential owing to the growth worldwide of the diabetic population. Targeting the PPAR receptor is one strategy for the treatment of diabetes; the PPAR agonists rosiglitazone and pioglitazone are already on the market. Here we report the identification of a potent PPAR agonist, 15, whose PPAR gamma activation was more than 20 times better than that of rosiglitazone. Compound 15 was designed to incorporate an indole head with a carboxylic acid group, and 4-phenylbenzophenone tail to achieve a PPAR gamma EC(50) of 10 nm. Compound 15 showed the most potent PPAR gamma agonist activity among the compounds we investigated. To gain molecular insight into the improved potency of 15, a structural biology study and binding energy calculations were carried out. Superimposition of the X-ray structures of 15 and agonist 10 revealed that, even though they have the same indole head part, they adopt different conformations. The head part of 15 showed stronger interactions toward PPAR gamma; this could be due to the presence of the novel tail part 4-phenylbenzophenone, which could enhance the binding efficiency of 15 to PPAR gamma.