Browsing by Author "Lin, Wen-Hsing"

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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
;
Song, Jen-Shin
;
Lien, Tzu-Wen
;
Chang, Chun-Yu
;
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.
Design and Structural Analysis of Novel Pharmacophores for Potent and Selective Peroxisome Proliferator-activated Receptor gamma Agonists
(2009-04-23)
Lin, Chia-Hui
;
Peng, Yi-Hui
;
Coumar, Mohane Selvaraj
;
Chittimalla, Santhosh Kumar
;
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
;
Coumar, Mohane Selvaraj
;
Chu, Chang-Ying
;
Lin, Wen-Hsing
;
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
;
Coumar, Mohane Selvaraj
;
Chu, Chang-Ying
;
Lin, Wen-Hsing
;
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.
Diosgenin, a Plant-Derived Sapogenin, Exhibits Antiviral Activity in Vitro against Hepatitis C Virus
(2011-04-01)
Wang, Ya-Jean
;
Pan, Kao-Lu
;
Hsieh, Tsung-Chih
;
Chang, Teng-Yuan
;
Lin, Wen-Hsing
Diosgenirr (3 beta-hydroxy-5-spirostene, 1); a plant-derived sapogenin, is used as a dietary: supplement However, the biological effects of 1 related to viral replication remain unexplored. In this study, the effects of 1 on hepatitis C virus (HCV) replication were evaluated. Based on a reporter-based HCV subgenomic replicon system, 1 was found to inhibit HCV replication at low micromolar concentrations. The EC(50) (concentration at which 50% of HCV replication is inhibited) of 1 was 3.8 mu M No cellular toxicity was observed at this concentration.,Diosgenin, (1) also significantly reduced the levels of viral,RNA and viral proteins as evaluated by quantitative real-time reverse :transcriptase PCR and Western blot analysis, respectively. In addition, in an HCV antiviral system more closely aligned to all steps involved in the HCV infection and life cycle, 1 totally abolished HCV replication at 20 mu M. Moreover, 1 reduced the phosphorylation of signal transducer and activator of transcription 3. A combination of 1:and interferon-alpha exerted an additive effect on the resultant anti-HCV activity.
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
;
Yeh, Teng-Kuang
;
Jiaang, Weir-Torn
;
Yen, Kuei-Jung
;
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
;
Chu, Chang-Ying
;
Lin, Cheng-Wei
;
Shiao, Hui-Yi
;
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
;
Tsai, Ming-Tsung
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Chu, Chang-Ying
;
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.
Structural Basis for the Improved Potency of Peroxisome Proliferator-Activated Receptor (PPAR) Agonists
(2010-10-04)
Peng, Yi-Hui
;
Coumar, Mohane Selvaraj
;
Leou, Jiun-Shyang
;
Wu, Jian-Sung
;
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
;
Coumar, Mohane Selvaraj
;
Leou, Jiun-Shyang
;
Wu, Jian-Sung
;
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.
Suppression of Stat3 activity sensitizes gefitinib-resistant non small cell lung cancer cells
(2011-06-01)
Chiu, Huan-Chih
;
Chou, Ding-Li
;
Huang, Chin-Ting
;
Lin, Wen-Hsing
;
Lien, Tzu-Wen
Epidermal growth factor receptor (EGFR) is a proven therapeutic target to treat a small subset of non small cell lung cancer (NSCLC) harboring activating mutations within the EGFR gene. However, many NSCLC patients are not sensitive to EGFR inhibitors, suggesting that other factors are implicated in survival of NSCLC cells. Signal transducers and activators of transcription 3 (Stat3) function as transcription factor to mediate cell survival and differentiation and the dysregulation of Stat3 has been discovered in a number of cancers. In this study, we found that a small molecule, reactivation of p53 and induction of tumor cell apoptosis (RITA), showed anti-cancer activity against gefitinib-resistant H1650 cells through a p53-independent pathway. Stat3 suppression by RITA attracted our attention to investigate the role of Stat3 in sustaining survival of H1650 cells. Pharmacological and genetic approaches were employed to down-regulate Stat3 in H1650 cells. WP1066, a known Stat3 inhibitor, was shown to exhibit inhibitory effect on the growth of H1650 cells. Meanwhile, apoptosis activation by siRNA-mediated down-regulation of Stat3 in H1650 cells provides more direct evidence for the involvement of Stat3 in viability maintenance of H1650 cells. Moreover, as a novel identified Stat3 inhibitor, RITA increased doxorubicin sensitivity of H1650 cells in vitro and in vivo, suggesting that doxorubicin accompanied with Stat3 inhibitors may be considered as an alternative strategy to treat NSCLC patients who have inherent resistance to doxorubicin. Overall, our observations reveal that targeting Stat3 may be an effective treatment for certain NSCLC cells with oncogenic addition to Stat3. (C) 2011 Elsevier Inc. All rights reserved.