Publications by authors named "Ya-Ling Chang"

40 Publications

Phenolic compositions and antioxidant properties of leaves of eight persimmon varieties harvested in different periods.

Food Chem 2019 Aug 12;289:74-83. Epub 2019 Mar 12.

Institute of Food Safety and Health Risk Assessment, National Yang-Ming University, 155, Sec. 2, Linong Street, Taipei 11221, Taiwan; Department of Nutrition and Master Program for Food and Drug Safety, China Medical University, 91, Hsueh-Shih Road, Taichung 40402, Taiwan; Department of Food Nutrition and Health Biotechnology, Asia University, 500, Lioufeng Rd., Wufeng, Taichung 41354, Taiwan. Electronic address:

The compositions and contents of antioxidant components and antioxidant attributes (scavenging DPPH radicals, TEAC, ferric reducing power and inhibiting Cu-induced human LDL oxidation) for the leaves of eight persimmon varieties harvested from Sep. to Nov. were determined. Harvest time and variety were important factors affecting the compositions and contents of phenolic compounds in persimmon leaves; moreover, phenolic contents (polyphenol, flavonoid, condensed tannin and phenolic acid) of the leaves were significantly correlated with their antioxidant activities. For each variety, the leaves harvested in months with higher temperature, solar radiation and sunshine duration had higher phenolic contents contributing to better antioxidant properties (ranking: Sep. > Oct. > Nov.). In addition, the compositions and contents of phenolic components and antioxidant capacities for the leaves from various persimmon varieties were also different. The leaves of persimmon varieties belonging to pollination constant and astringent (PCA) had higher phenolic contents and also presented better antioxidant effects.
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http://dx.doi.org/10.1016/j.foodchem.2019.03.048DOI Listing
August 2019

Negative voltage modulated multi-level resistive switching by using a Cr/BaTiO/TiN structure and quantum conductance through evidence of HO sensing mechanism.

Sci Rep 2017 07 5;7(1):4735. Epub 2017 Jul 5.

Department of Materials Science and Engineering, National Taiwan University, Taipei, 106, Taiwan.

Negative voltage modulated multi-level resistive switching with quantum conductance during staircase-type RESET and its transport characteristics in Cr/BaTiO/TiN structure have been investigated for the first time. The as-deposited amorphous BaTiO film has been confirmed by high-resolution transmission electron microscopy. X-ray photo-electron spectroscopy shows different oxidation states of Ba in the switching material, which is responsible for tunable more than 10 resistance states by varying negative stop voltage owing to slow decay value of RESET slope (217.39 mV/decade). Quantum conductance phenomenon has been observed in staircase RESET cycle of the memory devices. By inspecting the oxidation states of Ba and Ba through measuring HO with a low concentration of 1 nM in electrolyte/BaTiO/SiO/p-Si structure, the switching mechanism of each HRS level as well as the multi-level phenomenon has been explained by gradual dissolution of oxygen vacancy filament. Along with negative stop voltage modulated multi-level, current compliance dependent multi-level has also been demonstrated and resistance ratio up to 2000 has been achieved even for a thin (<5 nm) switching material. By considering oxidation-reduction of the conducting filaments, the current-voltage switching curve has been simulated as well. Hence, multi-level resistive switching of Cr/BaTiO/TiN structure implies the promising applications in high dense, multistate non-volatile memories in near future.
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http://dx.doi.org/10.1038/s41598-017-05059-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5498493PMC
July 2017

Phenolic compositions and antioxidant attributes of leaves and stems from three inbred varieties of Lycium chinense Miller harvested at various times.

Food Chem 2017 Jan 22;215:284-91. Epub 2016 Jun 22.

Department of Health Diet and Industry Management, Chung Shan Medical University, and Department of Nutrition, Chung Shan Medical University Hospital, 110, Sec. 1, Jianguo N. Road, Taichung City 40201, Taiwan; Department of Nutrition, China Medical University, 91, Hsueh-Shih Road, Taichung 40402, Taiwan. Electronic address:

Antioxidant components and properties (assayed by scavenging DPPH radicals, TEAC, reducing power, and inhibiting Cu(2+)-induced human LDL oxidation) of leaves and stems from three inbred varieties of Lycium chinense Miller, namely ML01, ML02 and ML02-TY, harvested from January to April were studied. Their flavonoid and phenolic acid compositions were also analyzed by HPLC. For each variety, the leaves and stems collected in higher temperature month had higher contents of total phenol, total flavonoid and condensed tannin. Contents of these components in the samples collected in different months were in the order: April (22.3°C)>March (18.0°C)>January (15.6°C)>February (15.4°C). Antioxidant activities of the leaves and stems for all assays also showed similar trends. The samples from different varieties collected in the same month also possessed different phenolic compositions and contents and antioxidant activities. Their antioxidant activities were significantly correlated with flavonoid and phenolic contents.
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http://dx.doi.org/10.1016/j.foodchem.2016.06.072DOI Listing
January 2017

Speed and temporal-distance adaptations during non-motorized treadmill walking in stroke and non-disabled individuals.

Eur J Phys Rehabil Med 2017 Dec 21;53(6):863-869. Epub 2016 Jul 21.

Department of Physical Medicine & Rehabilitation, Taipei Veterans General Hospital, Taipei, Taiwan -

Background: Treadmill training has received widespread attention to facilitate gait retraining and allow gait analysis in the stroke population in recent decades. While previous studies have used motorized treadmills for gait analysis or training, no study has investigated the use of non-motorized treadmill (NMT) in a rehabilitation setting.

Aim: The aim of this study was to compare the speed between overground (OG) and NMT walking and measure the adaptation of the gait pattern from comfortable to maximal walking speeds during NMT walking in participants with stroke and non-disabled individuals.

Design: Cross-sectional study.

Setting: Tertiary care center.

Population: Twenty chronic hemiplegic stroke patients and 20 non-disabled controls.

Methods: The speeds attained OG and on a NMT were compared within each group. Cadence and stride length were measured while walking on the NMT. Adaptations of the gait pattern from comfortable to maximal walking speeds during NMT walking were measured in both groups.

Results: In both groups, when walking on the NMT, participants walked with significantly lower speed than on the ground. While on the NMT, the non-disabled individuals significantly increased the cadence and stride length simultaneously as the speed increased. The participants with stroke significantly increased the cadence but showed little increase in stride length with increased speed.

Conclusions: Participants ambulated with significantly lower speeds on the NMT than during OG. Participants with stroke use a different strategy to increase walking velocity during NMT walking, relying mostly on increasing the cadence.

Clinical Rehabilitation Impact: Lower speed during NMT walking indicated that lesser total distance covered with NMT training when compared to OG gait training, which may inadvertently impact training amount. This is an important obstacle to overcome in order for NMT to be used effectively in the retraining of gait in patients with stroke.
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http://dx.doi.org/10.23736/S1973-9087.16.04242-8DOI Listing
December 2017

The synergic effect of vincristine and vorinostat in leukemia in vitro and in vivo.

J Hematol Oncol 2015 Jul 10;8:82. Epub 2015 Jul 10.

Pharmacological Institute, College of Medicine, National Taiwan University, No. 1, Jen-Ai Road, Sec. 1, Taipei, Taiwan.

Background: Combination therapy is a key strategy for minimizing drug resistance, a common problem in cancer therapy. The microtubule-depolymerizing agent vincristine is widely used in the treatment of acute leukemia. In order to decrease toxicity and chemoresistance of vincristine, this study will investigate the effects of combination vincristine and vorinostat (suberoylanilide hydroxamic acid (SAHA)), a pan-histone deacetylase inhibitor, on human acute T cell lymphoblastic leukemia cells.

Methods: Cell viability experiments were determined by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay, and cell cycle distributions as well as mitochondria membrane potential were analyzed by flow cytometry. In vitro tubulin polymerization assay was used to test tubulin assembly, and immunofluorescence analysis was performed to detect microtubule distribution and morphology. In vivo effect of the combination was evaluated by a MOLT-4 xenograft model. Statistical analysis was assessed by Bonferroni's t test.

Results: Cell viability showed that the combination of vincristine and SAHA exhibited greater cytotoxicity with an IC50 value of 0.88 nM, compared to each drug alone, 3.3 and 840 nM. This combination synergically induced G2/M arrest, followed by an increase in cell number at the sub-G1 phase and caspase activation. Moreover, the results of vincristine combined with an HDAC6 inhibitor (tubastatin A), which acetylated α-tubulin, were consistent with the effects of vincristine/SAHA co-treatment, thus suggesting that SAHA may alter microtubule dynamics through HDAC6 inhibition.

Conclusion: These findings indicate that the combination of vincristine and SAHA on T cell leukemic cells resulted in a change in microtubule dynamics contributing to M phase arrest followed by induction of the apoptotic pathway. These data suggest that the combination effect of vincristine/SAHA could have an important preclinical basis for future clinical trial testing.
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http://dx.doi.org/10.1186/s13045-015-0176-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4504084PMC
July 2015

Heteronemin, a Spongean Sesterterpene, Induces Cell Apoptosis and Autophagy in Human Renal Carcinoma Cells.

Biomed Res Int 2015 18;2015:738241. Epub 2015 May 18.

Pharmacological Institute, College of Medicine, National Taiwan University, No. 1 Jen-Ai Road, Section 1, Taipei 10051, Taiwan.

Heteronemin is a bioactive marine sesterterpene isolated from the sponge Hyrtios sp. Previous reports have shown that heteronemin possesses anticancer activity. Here, heteronemin displayed cytotoxic effects against three human cancer cell lines (A549, ACHN, and A498) and exhibited potent activity in A498 human renal carcinoma cells, with an IC₅₀ value of 1.57 μM by MTT assay and a GI50 value of 0.77 μM by SRB assay. Heteronemin initiates apoptotic cell death by downregulating Bcl-2 and Bcl-xL and upregulating Bax, leading to the disruption of the mitochondrial membrane potential and the release of cytochrome c from the mitochondria. These effects were associated with the activation of caspase-3/caspase-8/caspase-9, followed by PARP cleavage. Furthermore, heteronemin inhibited the phosphorylation of AKT signaling pathway and ERK and activated p38 and JNK. The specific inhibition of the p38 pathway by SB203580 or p38 siRNA treatment reversed the heteronemin-induced cytotoxicity and apoptotic signaling. Heteronemin also induced autophagy in A498 cells, and treatment with chloroquine (autophagy inhibitor) or SP600125 (JNK inhibitor) inhibited autophagy and increased heteronemin-induced cytotoxicity and apoptotic signaling. Taken together, this study proposes a novel treatment paradigm in which the combination of heteronemin and autophagy inhibitors leads to enhanced RCC cell apoptosis.
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http://dx.doi.org/10.1155/2015/738241DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4450260PMC
March 2016

A biologically inspired lung-on-a-chip device for the study of protein-induced lung inflammation.

Integr Biol (Camb) 2015 Feb;7(2):162-9

Institute of NanoEngineering and MicroSystems, National Tsing Hua University, Hsinchu, Taiwan, Republic of China.

This study reports a biomimetic microsystem that reconstitutes the lung microenvironment for monitoring the role of eosinophil cationic protein (ECP) in lung inflammation. ECP induces the airway epithelial cell expression of CXCL-12, which in turn stimulates the migration of fibrocytes towards the epithelium. This two-layered microfluidic system provides a feasible platform for perfusion culture, and was used in this study to reveal that the CXCL12-CXCR4 axis mediates ECP induced fibrocyte extravasation in lung inflammation. This 'lung-on-a-chip' microdevice serves as a dynamic transwell system by introducing a flow that can reconstitute the blood vessel-tissue interface for in vitro assays, enhancing pre-clinical studies. We made an attempt to develop a new microfluidic model which could not only simulate the transwell for studying cell migration, but could also study the migration in the presence of a flow mimicking the physiological conditions in the body. As blood vessels are the integral part of our body, this model gives an opportunity to study more realistic in vitro models of organs where the blood vessel i.e. flow based migration is involved.
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http://dx.doi.org/10.1039/c4ib00239cDOI Listing
February 2015

miR-146a and miR-370 coordinate enterovirus 71-induced cell apoptosis through targeting SOS1 and GADD45β.

Cell Microbiol 2015 Jun 24;17(6):802-18. Epub 2015 Jan 24.

Institute of Molecular Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan.

Enterovirus 71 (EV71) is an emerging life-threatening pathogen particularly in the Asia-Pacific region. The major pathogenic feature in EV71-infected cells is apoptosis. However, which molecular mechanism mainly contributes to EV71-induced apoptosis is not investigated thoroughly. MicroRNAs (MiRNAs), the newly discovered molecules, govern a wide range of biological functions through post-transcriptional regulation including viral pathogenesis. Whether miRNAs and messenger RNAs (mRNAs) coordinate to trigger host cell apoptosis in EV71 infection was investigated in this study. We conducted an apoptosis-oriented approach using both mRNA and miRNA profiling and bioinformatic analysis. We identified two major apoptosis-associated signalling pathways, Bcl2 antagonist of cell death (BAD) phosphorylation and p53-dependent apoptosis pathways, in which Son of sevenless homolog 1 (SOS1) and Growth arrest and DNA damage-inducible protein 45β (GADD45β) were predicted as targets of miR-146a and miR-370 respectively. Luciferase reporter assays and Western blots demonstrated the negative regulation between miR-146a and SOS1 and between miR-370 and GADD45β. Silencing of miR-146a restored SOS1 expression and partially attenuated EV71 infection-induced apoptosis. Conversely, ectopic expression of miR-370 decreased virus infection-induced GADD45β expression and also diminished apoptosis. Finally, the transfection of antagomiR-146a and miR-370 contributed to attenuating EV71 infection-induced apoptosis. Herein we clearly demonstrate that EV71-induced cell apoptosis is partly governed by altered miRNAs.
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http://dx.doi.org/10.1111/cmi.12401DOI Listing
June 2015

Depletion of 4E-BP1 and regulation of autophagy lead to YXM110-induced anticancer effects.

Carcinogenesis 2013 Sep 30;34(9):2050-60. Epub 2013 Apr 30.

Pharmacological Institute, College of Medicine, National Taiwan University, Taipei 10051, Taiwan.

Natural products have always been a profuse database for developing new chemotherapeutics. YXM110 is a newly synthesized phenanthroquinolizidines that exhibits excellent anticancer activity in numerous cancer cells. In this study, we examined the anticancer mechanisms of YXM110 both in vitro and in vivo. Protein level of 4E-binding protein 1, which is crucial in cap-independent translation, was decreased significantly after YXM110 treatment via c-Jun N-terminal kinases-mediated proteasomal degradation. Moreover, the effects of YXM110 were associated with several characteristics of autophagy, including accumulation of autophagic vacuoles, elevation of Atg12-Atg5 and light chain 3 (LC3)-II, and levels of GFP-LC3 puncta. The results suggested that depletion of Mcl-1 contributes to YXM110-triggered autophagy, whereas downregulation of lysosomal-related genes could cause autophagy impairment. Furthermore, YXM110-induced cell death was prevented by autophagy inhibitor 3-methyladenine and Atg5 silencing, indicating that YXM110-mediated autophagy impairment leads to cancer cell death. These data reveal key mechanisms that support the further development of YXM110 as a promising anticancer agent.
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http://dx.doi.org/10.1093/carcin/bgt146DOI Listing
September 2013

Inhibition of CIP2A determines erlotinib-induced apoptosis in hepatocellular carcinoma.

Biochem Pharmacol 2013 Feb 23;85(3):356-66. Epub 2012 Nov 23.

Department of Medical Research, National Taiwan University Hospital, Taipei, Taiwan.

Erlotinib is a small-molecular inhibitor of epidermal growth factor receptor (EGFR). Here, we identify that cancerous inhibitor of protein phosphatase 2A (CIP2A) is a major determinant mediating erlotinib-induced apoptosis in hepatocellular carcinoma (HCC). Erlotinib showed differential effects on apoptosis in 4 human HCC cell lines. Erlotinib induced significant apoptosis in Hep3B and PLC5 cell lines; however, Huh-7 and HA59T cell lines showed resistance to erlotinib-induced apoptosis at all tested doses. Down-regulation of CIP2A, a cellular inhibitor of protein phosphatase 2A (PP2A), mediated the apoptotic effect of erlotinib in HCC. Erlotinib inhibited CIP2A in a dose- and time-dependent manner in all sensitive HCC cells whereas no alterations in CIP2A were found in resistant cells. Overexpression of CIP2A upregulated phospho-Akt and protected Hep3B cells from erlotinib-induced apoptosis. In addition, silencing CIP2A by siRNA restored the effects of erlotinib in Huh-7 cells. Moreover, adding okadaic acid, a PP2A inhibitor, abolished the effects of erlotinib on apoptosis in Hep3B cells; and forskolin, a PP2A agonist enhanced the effect of erlotinib in resistant HA59T cells. Combining Akt inhibitor MK-2206 with erlotinib restored the sensitivity of HA59T cells to erlotinib. Furthermore, in vivo xenograft data showed that erlotinib inhibited the growth of PLC5 tumor but had no effect on Huh-7 tumor. Erlotinib downregulated CIP2A and upregulated PP2A activity in PLC5 tumors, but not in Huh-7 tumors. In conclusion, inhibition of CIP2A determines the effects of erlotinib on apoptosis in HCC. CIP2A may be useful as a therapeutic biomarker for predicting clinical response to erlotinib in HCC treatment.
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http://dx.doi.org/10.1016/j.bcp.2012.11.009DOI Listing
February 2013

α-Tomatine-mediated anti-cancer activity in vitro and in vivo through cell cycle- and caspase-independent pathways.

PLoS One 2012 6;7(9):e44093. Epub 2012 Sep 6.

Phamacological Institute, College of Medicine, National Taiwan University, Taipei, Taiwan.

α-Tomatine, a tomato glycoalkaloid, has been reported to possess antibiotic properties against human pathogens. However, the mechanism of its action against leukemia remains unclear. In this study, the therapeutic potential of α-tomatine against leukemic cells was evaluated in vitro and in vivo. Cell viability experiments showed that α-tomatine had significant cytotoxic effects on the human leukemia cancer cell lines HL60 and K562, and the cells were found to be in the Annexin V-positive/propidium iodide-negative phase of cell death. In addition, α-tomatine induced both HL60 and K562 cell apoptosis in a cell cycle- and caspase-independent manner. α-Tomatine exposure led to a loss of the mitochrondrial membrane potential, and this finding was consistent with that observed on activation of the Bak and Mcl-1 short form (Mcl-1s) proteins. Exposure to α-tomatine also triggered the release of the apoptosis-inducing factor (AIF) from the mitochondria into the nucleus and down-regulated survivin expression. Furthermore, α-tomatine significantly inhibited HL60 xenograft tumor growth without causing loss of body weight in severe combined immunodeficiency (SCID) mice. Immunohistochemical test showed that the reduced tumor growth in the α-tomatine-treated mice was a result of increased apoptosis, which was associated with increased translocation of AIF in the nucleus and decreased survivin expression ex vivo. These results suggest that α-tomatine may be a candidate for leukemia treatment.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0044093PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3435411PMC
May 2013

Moscatilin inhibits migration and metastasis of human breast cancer MDA-MB-231 cells through inhibition of Akt and Twist signaling pathway.

J Mol Med (Berl) 2013 Mar 8;91(3):347-56. Epub 2012 Sep 8.

Phamacological Institute, College of Medicine, National Taiwan University, No. 1, Jen-Ai Road, Sec. 1, Taipei, Taiwan.

Breast cancer metastasis is more resistant to chemotherapy and radiotherapy than is cancer of the visceral tissues; therefore, new treatment strategies are urgently needed. Moscatilin, derived from the orchid Dendrobrium loddigesii, has shown anticancer activity. We evaluated the mechanism by which moscatilin suppresses the migration and metastasis of human breast cancer MDA-MB-231 cells in vitro and in vivo. We demonstrated that moscatilin significantly inhibits MDA-MB-231 cell migration by using scratch assays and Boyden chambers. Transcriptional factors inducing epithelial-mesenchymal transition, such as Twist, Snail, and Akt, play important roles in cell migration and cancer metastasis. Moscatilin inhibited the mRNA and protein expression of Twist, but not that of Snail, and subsequently inhibited N-cadherin expression. However, these effects were reversed by constitutively expressing active myristoylated (myr)-Akt and Twist overexpression. Moscatilin also suppressed Akt phosphorylation. However, Akt overexpression reversed the inhibitory effects of moscatilin on phospho-Akt protein expression but not its effects on Twist. The moscatilin-mediated inhibition of cell migration was reversed by Akt and Twist overexpression, demonstrating that moscatilin blocked cell migration by inhibiting Akt and Twist. In an MDA-MB-231 metastatic animal model, moscatilin (100 mg/kg) significantly suppressed breast cancer metastasis to the lungs and reduced the number of metastatic lung nodules and lung weight without causing any toxicity. These results indicated that moscatilin inhibited MDA-MB-231 cell migration via Akt- and Twist-dependent pathways; this finding was consistent with moscatilin's antimetastatic activity in vivo. Therefore, moscatilin may be an effective compound for the prevention of human breast cancer metastasis.
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http://dx.doi.org/10.1007/s00109-012-0945-5DOI Listing
March 2013

CD14(+)S100A9(+) monocytic myeloid-derived suppressor cells and their clinical relevance in non-small cell lung cancer.

Am J Respir Crit Care Med 2012 Nov 6;186(10):1025-36. Epub 2012 Sep 6.

Pulmonary Research Center, Chang Gung Medical Foundation, Chang Gung University, 199, Tun-Hwa North Road, Taipei, Taiwan.

Rationale: Myeloid-derived suppressor cells (MDSCs) are a heterogeneous family of myeloid cells that suppress T-cell immunity in tumor-bearing hosts. Their clinical relevance remains unclear.

Objectives: To identify subtypes of myeloid-derived suppressor cells in patients with non-small cell lung cancer (NSCLC) and their clinical relevance.

Methods: CD11b(+)CD14(-) and CD11b(+)CD14(+) cells, determined and phenotyped by fluorescence-activated cell sorter analysis, in the peripheral blood mononuclear cells (PBMCs) of treatment-naive patients with advanced NSCLC were correlated with clinical data. T-cell activation in response to CD3/CD28 costimulation was determined by carboxy-fluorescein diacetate succinimidyl ester (CFSE) staining and ELISA analysis of IFN-γ. The percentage of CD11b(+)CD14(+)S100A9(+) cells in PBMCs was correlated with and tested as a predictor for treatment response in a cohort of patients prospectively receiving first-line cisplatin-based chemotherapy.

Measurements And Main Results: Patients with NSCLC had a significantly higher ratio of CD11b(+)CD14(+) cells than healthy subjects, which was correlated with poor performance status and poor response to chemotherapy. The depletion of these cells in the PBMC reversed the suppression of CD8(+) and CD4(+) T cells. Isolated CD11b(+)CD14(+) cells suppressed CD8(+) T-cell proliferation and IFN-γ production, and the former effect was attenuated by the inducible nitric oxide synthase (iNOS) inhibitor aminoguanidine hydrochloride, arginase inhibitor N-hydroxy-nor-l-arginine (nor-NOHA), and blocking antibodies for IL-4Rα(+) and IL-10. CD11b(+)CD14(+) cells were monocyte-like, expressing CD33(+), CD15(-/low), IL-4Rα(+), and S100A9(+) and producing iNOS, arginase, and several cytokines. The ratio of S100A9(+) cells positively correlated with the suppressive ability of the CD11b(+)CD14(+) cells, was associated with poor response to chemotherapy, and predicted shorter progression-free survival.

Conclusions: CD14(+)S100A9(+) inflammatory monocytes in patients with NSCLC are a distinct subset of MDSCs, which suppress T cells by arginase, iNOS, and the IL-13/IL-4Rα axis. The amount of these inflammatory monocytes is associated with poor response to chemotherapy. Clinical trial registered with www.clinicaltrials.gov (NCT 01204307).
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http://dx.doi.org/10.1164/rccm.201204-0636OCDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4132576PMC
November 2012

Aciculatin induces p53-dependent apoptosis via MDM2 depletion in human cancer cells in vitro and in vivo.

PLoS One 2012 13;7(8):e42192. Epub 2012 Aug 13.

Pharmacological Institute, College of Medicine, National Taiwan University, Taipei, Taiwan.

Aciculatin, a natural compound extracted from the medicinal herb Chrysopogon aciculatus, shows potent anti-cancer potency. This study is the first to prove that aciculatin induces cell death in human cancer cells and HCT116 mouse xenografts due to G1 arrest and subsequent apoptosis. The primary reason for cell cycle arrest and cell death was p53 accumulation followed by increased p21 level, dephosphorylation of Rb protein, PUMA expression, and induction of apoptotic signals such as cleavage of caspase-9, caspase-3, and PARP. We demonstrated that p53 allele-null (-/-) (p53-KO) HCT116 cells were more resistant to aciculatin than cells with wild-type p53 (+/+). The same result was achieved by knocking down p53 with siRNA in p53 wild-type cells, indicating that p53 plays a crucial role in aciculatin-induced apoptosis. Although DNA damage is the most common event leading to p53 activation, we found only weak evidence of DNA damage after aciculatin treatment. Interestingly, the aciculatin-induced downregulation of MDM2, an important negative regulator of p53, contributed to p53 accumulation. The anti-cancer activity and importance of p53 after aciculatin treatment were also confirmed in the HCT116 xenograft models. Collectively, these results indicate that aciculatin treatment induces cell cycle arrest and apoptosis via inhibition of MDM2 expression, thereby inducing p53 accumulation without significant DNA damage and genome toxicity.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0042192PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3418269PMC
April 2013

Physalin F induces cell apoptosis in human renal carcinoma cells by targeting NF-kappaB and generating reactive oxygen species.

PLoS One 2012 16;7(7):e40727. Epub 2012 Jul 16.

Department of Pharmacology, National Taiwan University, Taipei, Taiwan.

Background: The aim of this study was to determine the molecular mechanisms of physalin F, an effective purified extract of Physalis angulata L. (Solanacae), in renal carcinoma A498 cells.

Methodology/principal Findings: Physalin F was observed to significantly induce cytotoxicity of three human renal carcinoma A498, ACHN, and UO-31 cells in a concentration-dependent manner; this was especially potent in A498 cells. The physalin F-induced cell apoptosis of A498 cells was characterized by MTT assay, nuclear DNA fragmentation and chromatin condensation. Using flow cytometry analysis, physalin F induced A498 cell apoptosis as demonstrated by the accumulation of the sub-G1 phase in a concentration- and time-dependent manner. Moreover, physalin F-mediated accumulation of reactive oxygen species (ROS) caused Bcl-2 family proteins, Bcl-2, and Bcl-xL degradation, which led to disruption of mitochondrial membrane potential and release of cytochrome c from the mitochondria into the cytosol. These effects were associated with induction of caspase-3 and caspase-9 activity, which led to poly(ADP-ribose) polymerase cleavage. However, the antioxidant N-acetyl-(L)-cysteine (NAC) and glutathione (GSH) resulted in the inhibition of these events and reversed physalin F-induced cell apoptosis. In addition, physalin F suppressed NF-κB activity and nuclear translocation of p65 and p50, which was reversed by NAC and GSH.

Conclusion: Physalin F induced cell apoptosis through the ROS-mediated mitochondrial pathway and suppressed NF-κB activation in human renal cancer A498 cells. Thus, physalin F appears to be a promising anti-cancer agent worthy of further clinical development.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0040727PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3398016PMC
March 2013

Reduced nuclear factor-κB repressing factor: a link toward systemic inflammation in COPD.

Eur Respir J 2012 Oct 22;40(4):863-73. Epub 2012 Mar 22.

Dept of Thoracic Medicine Chang Gung Memorial Hospital, Chang Gung University College of Medicine, 199 Tun-Hwa North Road, Taipei, Taiwan.

Chronic systemic inflammation is implicated in the systemic manifestations and, probably, the excess mortality risk of chronic obstructive pulmonary disease (COPD). The role of nuclear factor (NF)-κB repressing factor (NRF), a DNA-binding, protein-inhibiting NF-κB response gene, in human diseases has not been explored. We hypothesised that the NRF-negative regulatory mechanism is impaired in COPD peripheral blood mononuclear cells (PBMCs) leading to excessive interleukin (IL)-8/CXCL8 production. NRF expression, NF-κB activation, IL-8/CXCL8 release and intracellular oxidative stress were assessed in PBMCs of normal subjects and stable COPD patients. Primary PBMCs with NRF overexpression, NRF knockdown and exposure to H(2)O(2) were used to elucidate the mechanisms. Stable COPD patients, especially those with severe COPD, showed decreased NRF expression, enhanced NF-κB activation and increased IL-8/CXCL8 release in PBMCs compared with normal subjects. This was associated with reduced NRF and increased RNA polymerase II occupancy at the IL-8/CXCL8 promoter. NRF knockdown enhanced IL-8/CXCL8 production in normal PBMCs, whilst NRF overexpression attenuated IL-8/CXCL8 production. Intracellular oxidative stress was increased in COPD PBMCs. H(2)O(2)-decreased NRF expression and -enhanced IL-8/CXCL8 production was augmented in COPD PBMCs. NRF expression is reduced in PBMCs of stable COPD patients, probably through oxidative stress, leading to increased production of IL-8/CXCL8 and potentially chronic systemic inflammation.
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http://dx.doi.org/10.1183/09031936.00146811DOI Listing
October 2012

Dehydrocostuslactone suppresses angiogenesis in vitro and in vivo through inhibition of Akt/GSK-3β and mTOR signaling pathways.

PLoS One 2012 16;7(2):e31195. Epub 2012 Feb 16.

Pharmacological Institute, College of Medicine, National Taiwan University, Taipei, Taiwan.

The traditional Chinese medicine component dehydrocostuslactone (DHC) isolated from Saussurea costus (Falc.) Lipschitz, has been shown to have anti-cancer activity. Angiogenesis is an essential process in the growth and progression of cancer. In this study, we demonstrated, for the first time, the anti-angiogenic mechanism of action of DHC to be via the induction of cell cycle progression at the G0/G1 phase due to abrogation of the Akt/glycogen synthase kinase-3β (GSK-3β)/cyclin D1 and mTOR signaling pathway. First, we demonstrated that DHC has an anti-angiogenic effect in the matrigel-plug nude mice model and an inhibitory effect on human umbilical vein endothelial cell (HUVEC) proliferation and capillary-like tube formation in vitro. DHC caused G0/G1 cell cycle arrest, which was associated with the down-regulation of cyclin D1 expression, leading to the suppression of retinoblastoma protein phosphorylation and subsequent inhibition of cyclin A and cdk2 expression. With respect to the molecular mechanisms underlying the DHC-induced cyclin D1 down-regulation, this study demonstrated that DHC significantly inhibits Akt expression, resulting in the suppression of GSK-3β phosphorylation and mTOR expression. These effects are capable of regulating cyclin D1 degradation, but they were significantly reversed by constitutively active myristoylated (myr)-Akt. Furthermore, the abrogation of tube formation induced by DHC was also reversed by overexpression of Akt. And the co-treatment with LiCl and DHC significantly reversed the growth inhibition induced by DHC. Taken together, our study has identified Akt/GSK-3β and mTOR as important targets of DHC and has thus highlighted its potential application in angiogenesis-related diseases, such as cancer.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0031195PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3281050PMC
August 2012

Revealing the functions of the transketolase enzyme isoforms in Rhodopseudomonas palustris using a systems biology approach.

PLoS One 2011 8;6(12):e28329. Epub 2011 Dec 8.

Institute of Molecular and Cellular Biology, National Taiwan University, Taipei, Taiwan.

Background: Rhodopseudomonas palustris (R. palustris) is a purple non-sulfur anoxygenic phototrophic bacterium that belongs to the class of proteobacteria. It is capable of absorbing atmospheric carbon dioxide and converting it to biomass via the process of photosynthesis and the Calvin-Benson-Bassham (CBB) cycle. Transketolase is a key enzyme involved in the CBB cycle. Here, we reveal the functions of transketolase isoforms I and II in R. palustris using a systems biology approach.

Methodology/principal Findings: By measuring growth ability, we found that transketolase could enhance the autotrophic growth and biomass production of R. palustris. Microarray and real-time quantitative PCR revealed that transketolase isoforms I and II were involved in different carbon metabolic pathways. In addition, immunogold staining demonstrated that the two transketolase isoforms had different spatial localizations: transketolase I was primarily associated with the intracytoplasmic membrane (ICM) but transketolase II was mostly distributed in the cytoplasm. Comparative proteomic analysis and network construction of transketolase over-expression and negative control (NC) strains revealed that protein folding, transcriptional regulation, amino acid transport and CBB cycle-associated carbon metabolism were enriched in the transketolase I over-expressed strain. In contrast, ATP synthesis, carbohydrate transport, glycolysis-associated carbon metabolism and CBB cycle-associated carbon metabolism were enriched in the transketolase II over-expressed strain. Furthermore, ATP synthesis assays showed a significant increase in ATP synthesis in the transketolase II over-expressed strain. A PEPCK activity assay showed that PEPCK activity was higher in transketolase over-expressed strains than in the negative control strain.

Conclusions/significance: Taken together, our results indicate that the two isoforms of transketolase in R. palustris could affect photoautotrophic growth through both common and divergent metabolic mechanisms.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0028329PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3234253PMC
April 2012

Protopine, a novel microtubule-stabilizing agent, causes mitotic arrest and apoptotic cell death in human hormone-refractory prostate cancer cell lines.

Cancer Lett 2012 Feb 8;315(1):1-11. Epub 2011 Oct 8.

Pharmacological Institute, College of Medicine, National Taiwan University, Taipei, ROC.

In this study, we investigated the anticancer effect of protopine on human hormone-refractory prostate cancer (HRPC) cells. Protopine exhibited an anti-proliferative effect by induction of tubulin polymerization and mitotic arrest, which ultimately led to apoptotic cell death. The data suggest that protopine increased the activity of cyclin-dependent kinase 1 (Cdk1)/cyclin B1 complex and that contributed to cell apoptosis by modulating mitochondria-mediated signaling pathways, such as Bcl-2 phosphorylation and Mcl-1 down-regulation. In conclusion, the data suggest that protopine is a novel microtubule stabilizer with anticancer activity in HRPC cells through apoptotic pathway by modulating Cdk1 activity and Bcl-2 family of proteins.
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http://dx.doi.org/10.1016/j.canlet.2011.09.042DOI Listing
February 2012

The indazole derivative YD-3 specifically inhibits thrombin-induced angiogenesis in vitro and in vivo.

Shock 2010 Dec;34(6):580-5

Pharmacological Institute, College of Medicine, National Taiwan University, Taipei, Taiwan.

Angiogenesis is a process that involves endothelial cell proliferation, migration, invasion, and tube formation, and the inhibition of these processes has implications for angiogenesis-mediated disorders. The purpose of this study was to examine the antiangiogenic efficacy of YD-3 [1-benzyl-3(ethoxycarbonylphenyl)-indazole], a selective thrombin inhibitor, on thrombin-induced endothelial cell proliferation and neoangiogenesis in a murine Matrigel model. First, the effect of YD-3 on angiogenesis was evaluated in vivo using the mouse Matrigel implant model. Plugs treated with 1 and 10 μM of YD-3 inhibited neovascularization induced by thrombin, protease-activated receptor (PAR) 1, and PAR-4, but not by vascular endothelial growth factor, in a concentration-dependent manner over 7 days. These results indicate that YD-3 has specific antiangiogenic activity on thrombin. YD-3 also inhibited (in a concentration-dependent manner) the ability of thrombin, PAR-1, and PAR-4, but not PAR-2, to induce the proliferation of human umbilical vascular endothelial cells, using a [³H]thymidine incorporation assay. YD-3 predominantly inhibited thrombin-induced vascular endothelial growth factor receptor 2 (Flk-1) expression, but not extracellular signal-regulated kinase 1/2 phosphorylation, using Western blot analysis. YD-3 may have benefit in elucidating pathophysiology induced by thrombin-induced angiogenesis.
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http://dx.doi.org/10.1097/SHK.0b013e3181df00a3DOI Listing
December 2010

Moscatilin, a bibenzyl derivative from the India orchid Dendrobrium loddigesii, suppresses tumor angiogenesis and growth in vitro and in vivo.

Cancer Lett 2010 Jun 28;292(2):163-70. Epub 2009 Dec 28.

Pharmacological Institute, College of Medicine, National Taiwan University, Taipei, Taiwan.

Attacking angiogenesis is considered an effective strategy for controls the expansion and metastasis of tumors and other related-diseases. The aim of this study was to assess the effects of moscatilin, a bibenzyl derivative, on VEGF and bFGF-induced angiogenesis in cultured human umbilical vein endothelial cells (HUVECs) in vitro and in vivo. Moscatilin significantly inhibited growth of lung cancer cell line A549 (NSCLC) and suppressed growth factor-induced neovascularization. In addition, VEGF- and bFGF-induced cell proliferation, migration, and tube formation of HUVECs was markedly inhibited by moscatilin. Western blotting analysis of cell signaling molecules indicated that moscatilin inhibited ERK1/2, Akt, and eNOS signaling pathways in HUVECs. These results suggest that inhibition of angiogenesis by moscatilin may be a major mechanism in cancer therapy.
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http://dx.doi.org/10.1016/j.canlet.2009.11.020DOI Listing
June 2010

CHM-1, a new vascular targeting agent, induces apoptosis of human umbilical vein endothelial cells via p53-mediated death receptor 5 up-regulation.

J Biol Chem 2010 Feb 11;285(8):5497-506. Epub 2009 Dec 11.

Pharmacological Institute, College of Medicine, National Taiwan University, Taipei 10051, Taiwan.

CHM-1 (2'-fluoro-6,7-methylenedioxy-2-phenyl-4-quinolone) has been identified as a potent antitumor agent in human hepatocellular carcinoma; however, its role in tumor angiogenesis is unclear. This study investigated the effects of CHM-1 and the mechanisms by which it exerts its antiangiogenic and vascular disrupting properties. Using a xenograft model antitumor assay, we found that CHM-1 significantly inhibits tumor growth and microvessel formation. Flow cytometry, immunofluorescence microscopy, and cell death enzyme-linked immunosorbent assay kit revealed that CHM-1 inhibits growth of human umbilical vein endothelial cells (HUVEC) by induction of apoptotic cell death in a concentration-dependent manner. CHM-1 also suppresses HUVEC migration and capillary-like tube formation. We were able to correlate CHM-1-induced apoptosis in HUVEC with the cleavage of procaspase-3, -7, and -8, as well as with the cleavage of poly(ADP-ribose) polymerase by Western blotting assay. Such sensitization was achieved through up-regulation of death receptor 5 (DR5) but not DR4 or Fas. CHM-1 was also capable of increasing the expression level of p53, and most importantly, the induction of DR5 by CHM-1 was abolished by p53 small interfering RNA. Taken together, the results of this study indicate that CHM-1 exhibits vascular targeting activity associated with the induction of DR5-mediated endothelial cell apoptosis through p53 up-regulation, which suggests its potential as an antivascular and antitumor therapeutic agent.
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http://dx.doi.org/10.1074/jbc.M109.036277DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2820778PMC
February 2010

Evodiamine represses hypoxia-induced inflammatory proteins expression and hypoxia-inducible factor 1alpha accumulation in RAW264.7.

Shock 2009 Sep;32(3):263-9

Phamacological Institute, College of Medicine, National Taiwan University, Taipei, Taiwan.

Inflammation and low oxygen diffusion are recognized characteristics of cardiovascular diseases such as atherosclerosis. Evodiamine, extracted from the traditional Chinese herb, Evodia rutaecarpa, is a bioactive anti-inflammatory alkaloid. The objective of this study was to investigate whether evodiamine could repress hypoxia-induced inflammatory response. We showed that evodiamine repressed not only COX-2 and iNOS expression but also prostaglandin E2 release in a concentration-dependent manner under hypoxic conditions. Furthermore, our studies indicated that COX-2 mRNA was inhibited by evodiamine, implying that transcriptional activity is involved in the mechanistic pathway. It is striking that hypoxia-inducible factor 1alpha (HIF-1alpha) inhibitor, camptothecin, suppressed hypoxia-induced COX-2 expression rather than pyrrolidine dithiocarbamate, a nuclear factor kappaB inhibitor. In addition, our studies have confirmed that evodiamine inhibited HIF-1alpha, which accounted for the transcriptional activity of COX-2, rather than nuclear factor kappaB in RAW264.7 cells. Finally, evodiamine did not affect either the level of HIF-1alpha mRNA or the degradation rate of HIF-1alpha protein, but it regulated the translational process of HIF-1alpha. We found that hypoxia-evoked phosphorylation of Akt and p70S6K was blocked after evodiamine treatment, in addition to the inhibition of phosphorylation of 4E-BP. These results suggest that the mechanism of repression of hypoxia-induced COX-2 expression by evodiamine is through the inhibition of HIF-1alpha at the translational level and is primarily mediated via dephosphorylation of Akt and p70S6K. Therefore, evodiamine could be an effective therapeutic agent against inflammatory diseases involving hypoxia.
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http://dx.doi.org/10.1097/SHK.0b013e31819940cbDOI Listing
September 2009

Baicalein attenuates intimal hyperplasia after rat carotid balloon injury through arresting cell-cycle progression and inhibiting ERK, Akt, and NF-kappaB activity in vascular smooth-muscle cells.

Naunyn Schmiedebergs Arch Pharmacol 2008 Dec 29;378(6):579-88. Epub 2008 Jul 29.

Pharmacological Institute, College of Medicine, National Taiwan University, Taipei, Taiwan.

Baicalein (5,6,7-trioxyflavone-7-O-beta-D-glucuronide) derived from the Chinese herb Scutellaria baicalensis is well known as a lipoxygenase inhibitor. We investigated baicalein-mediated inhibitory effects on vascular smooth-muscle cell (VSMC) proliferation and intimal hyperplasia by balloon angioplasty in the rat. In vascular injury studies, baicalein significantly suppressed intimal hyperplasia by balloon angioplasty. Baicalein significantly inhibited cell proliferation via a lipoxygenase-independent pathway using [(3)H]thymidine incorporation, 3-(4,5-dimethylthiazol-2-yl)2,5-diphenyltetrazolium bromide (MTT), and flow cytometry assays. At the concentrations used, no cytotoxic effect on cell culture was found. Baicalein blocks cell-cycle progression in S/G2/M phase, consistent with the cell-cycle effects, baicalein significant inhibited cyclin D1, p42/44 mitogen-activated protein kinase (MAPK), and Akt phosphorylation without change in the other cell-cycle regulatory proteins. Furthermore, baicalein attenuated serum-induced deoxyribonucleic acid (DNA) binding activity of nuclear factor kappa B (NF-kappaB). These results show that baicalein blocks cell proliferation via blocking cell-cycle progression and proliferating events, including p42/44 MAPK and Akt activations as well as NF-kappaB activation. It also inhibits intimal hyperplasia after balloon vascular injury in the rat, indicating the therapeutic potential for treating restenosis after arterial injury.
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http://dx.doi.org/10.1007/s00210-008-0328-1DOI Listing
December 2008

CHM-1 inhibits hepatocyte growth factor-induced invasion of SK-Hep-1 human hepatocellular carcinoma cells by suppressing matrix metalloproteinase-9 expression.

Cancer Lett 2007 Nov 8;257(1):87-96. Epub 2007 Aug 8.

Pharmacological Institute, College of Medicine, National Taiwan University, No. 1, Jen-Ai Road, Sect. 1, Taipei, Taiwan.

Clinical observations suggest that hepatocyte growth factor (HGF) can promote invasion and metastasis in hepatocellular carcinoma. In this study, we found that HGF-stimulated invasion of SK-Hep-1 cells, together with increased expression of matrix metalloproteinase (MMP)-9. CHM-1 was identified from 2-phenyl-4-quinolone derivatives to potently inhibit HGF-induced cell invasion, proteolytic activity, and expression of MMP-9. CHM-1 significantly inhibited tyrosine autophosphorylation of c-Met induced by HGF. CHM-1 also suppressed HGF-induced Akt phosphorylation, and NF-kappaB activation, the downstream regulators of HGF/c-Met signaling, resulting in the inhibition of MMP-9. Thus, we suggest that CHM-1 is a potential therapeutic agent against tumor invasion.
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http://dx.doi.org/10.1016/j.canlet.2007.07.002DOI Listing
November 2007

Modulation of nucleosome-binding activity of FACT by poly(ADP-ribosyl)ation.

Nucleic Acids Res 2006 8;34(8):2398-407. Epub 2006 May 8.

Institute of Molecular Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan.

Chromatin-modifying factors play key roles in transcription, DNA replication and DNA repair. Post-translational modification of these proteins is largely responsible for regulating their activity. The FACT (facilitates chromatin transcription) complex, a heterodimer of hSpt16 and SSRP1, is a chromatin structure modulator whose involvement in transcription and DNA replication has been reported. Here we show that nucleosome binding activity of FACT complex is regulated by poly(ADP-ribosyl)ation. hSpt16, the large subunit of FACT, is poly(ADP-ribosyl)ated by poly(ADP-ribose) polymerase-1 (PARP-1) resulting from physical interaction between these two proteins. The level of hSpt16 poly(ADP-ribosyl)ation is elevated after genotoxic treatment and coincides with the activation of PARP-1. The enhanced hSpt16 poly(ADP-ribosyl)ation level correlates with the dissociation of FACT from chromatin in response to DNA damage. Our findings suggest that poly(ADP-ribosyl)ation of hSpt16 by PARP-1 play regulatory roles for FACT-mediated chromatin remodeling.
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http://dx.doi.org/10.1093/nar/gkl241DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1458519PMC
May 2006

YC-1 suppresses constitutive nuclear factor-kappaB activation and induces apoptosis in human prostate cancer cells.

Mol Cancer Ther 2005 Oct;4(10):1628-35

Pharmacological Institute, College of Medicine, National Taiwan University, No. 1, Jen-Ai Road, Taipei 100, Taiwan.

Although the indazole compound, YC-1, is reported to exert anticancer activities in several cancer cell types, its target and mechanism of action have not been well explored. The objectives of this study were to ascertain whether YC-1 directly induces apoptosis in prostate cancer cells and to explore the mechanism(s) whereby YC-1 causes cell death. Hormone-refractory metastatic human prostate cancer PC-3 cells were selected for this study. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide assay indicated that YC-1 suppresses growth of PC-3 cells in a concentration-dependent and time-dependent manner. Apoptosis was determined using 4',6-diamidino-2-phenylindole staining, and cell cycle progression was examined by FACScan flow cytometry. YC-1 treatment showed chromatin condensation and increased the percentage of PC-3 cells in the hypodiploid sub-G0-G1 phase, indicative of apoptosis. Additionally, exposure to YC-1 was found to induce activation of caspase-3 and cleavage of poly(ADP-ribose) polymerase. Translocation and activation of nuclear factor-kappaB (NF-kappaB) were determined by immunofluorescent staining and ELISA, respectively. The results showed that YC-1 abolished constitutive nuclear translocation and activation of NF-kappaB/p65. Furthermore, inhibition of inhibitor of kappaBalpha (IkappaBalpha) phosphorylation and accumulation of IkappaBalpha were observed. The antitumor effects of YC-1 were evaluated by measuring the growth of tumor xenografts in YC-1-treated severe combined immunodeficient mice. The volumes of PC-3 tumors produced in severe combined immunodeficient mice were observed to decline significantly after treatment with YC-1 compared with vehicle controls. We concluded that the antitumor effects of YC-1 in PC-3 cells include the induction of apoptosis and the suppression of NF-kappaB activation. Given these unique actions, further investigations of the effects of YC-1 against hormone-refractory prostate cancer are warranted.
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http://dx.doi.org/10.1158/1535-7163.MCT-05-0090DOI Listing
October 2005

YC-1 [3-(5'-hydroxymethyl-2'-furyl)-1-benzyl indazole] inhibits neointima formation in balloon-injured rat carotid through suppression of expressions and activities of matrix metalloproteinases 2 and 9.

J Pharmacol Exp Ther 2006 Jan 23;316(1):35-41. Epub 2005 Sep 23.

Pharmacological Institute, College of Medicine, National Taiwan University, 1 Jen-Ai Road, Sect. 1, Taipei, Taiwan.

Matrix metalloproteinases (MMPs), particularly MMP-2 and MMP-9, and postrevascularization production of vascular smooth muscle cells may play key roles in development of arterial restenosis. We investigated the inhibitory effect of 3-(5'-hydroxymethyl-2'-furyl)-1-benzyl indazole (YC-1), a benzyl indazole compound, on MMP-2 and MMP-9 activity in a balloon-injury rat carotid artery model. Injury was induced by inserting a balloon catheter through the common carotid artery; after 14 days, histopathological analysis using immunostaining and Western blotting revealed significant restenosis with neointimal formation that was associated with enhanced protein expression of MMP-2 and MMP-9. However, these effects were dose-dependently reduced by orally administered YC-1 (1-10 mg/kg). In addition, gelatin zymography demonstrated that increased MMP-2 and MMP-9 activity was diminished by YC-1 treatment. On the other hand, YC-1 inhibited hydrolysis of the fluorogenic quenching substrate Mca-Pro-Leu-Gly-Leu-Dpa-Ala-Arg-NH(2) by recombinant MMP-2 and MMP-9 with IC(50) values = 2.07 and 8.20 muM, respectively. Reverse transcription-polymerase chain reaction analysis of MMP-2 and MMP-9 mRNA revealed that YC-1 significantly inhibited mRNA levels of MMPs. Finally, for the YC-1 treatment group, we did not observe elevation of cGMP levels using enzyme-linked immunosorbent assay, suggesting that YC-1 inhibition of neointimal formation is not through a cGMP-elevating pathway. These data show YC-1 suppression of neointimal formation is dependent on its influence on MMP-2 and MMP-9 protein, mRNA expression, and activity, but not through a cGMP-elevating effect. YC-1 shows therapeutic potential for treatment of restenosis after angioplasty.
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http://dx.doi.org/10.1124/jpet.105.090563DOI Listing
January 2006

A potential role of YC-1 on the inhibition of cytokine release in peripheral blood mononuclear leukocytes and endotoxemic mouse models.

Thromb Haemost 2005 May;93(5):940-8

Pharmacological Institutes, College of Medicine, National Taiwan University, Taipei.

To evaluate the anti-sepsis potential of YC-1, we have examined the effect of YC-1 on the regulation of cytokine production in human leukocytes and endotoxemic mice. The data demonstrated that YC-1 showed a preferential inhibition on proinflammatory cytokine production without inhibition of cell growth or induction of cytotoxicity in human leukocytes. On the other hand, in the septic mouse model, treatment with an intraperitoneal application of LPS caused a cumulative death within 27 hours. The post-treatment administration of YC-1 significantly increased the survival rate in endotoxemic mice. Furthermore, several mediators were detected and the data showed that YC-1 profoundly blocked LPS-induced NO as well as TNF-alpha production, and prevented lung damage by histological examination. Samples from the animal model showed that LPS-induced NF-kappaB/DNA binding activity and consequent up-regulation of iNOS expression in tissues were abolished by post-administration of YC-1. Furthermore, YC-1, by itself, did not modify cGMP content while significantly inhibit LPS-induced cGMP formation, suggesting that YC-1-mediated effect was not through a cGMP-elevating pathway. Taken together, it is evident that the post-treatment administration of YC-1 after LPS application significantly inhibits NF-kappaB activation, iNOS expression, NO over-production, and cytokine release reaction resulting in an improved survival rate in endotoxemic mice. It is suggested that YC-1 may be a potential agent for the therapeutic treatment of sepsis.
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http://dx.doi.org/10.1160/TH04-03-0195DOI Listing
May 2005

YC-1 [3-(5'-hydroxymethyl-2'-furyl)-1-benzyl indazole] inhibits endothelial cell functions induced by angiogenic factors in vitro and angiogenesis in vivo models.

J Pharmacol Exp Ther 2005 Jul 22;314(1):35-42. Epub 2005 Mar 22.

Pharmacological Institute, College of Medicine, National Taiwan University, 1 Jen-Ai Road, Section 1, Taipei, Taiwan.

Angiogenesis is a process that involves endothelial cell proliferation, migration, invasion, and tube formation, and inhibition of these processes has implications for angiogenesis-mediated disorders. The purpose of this study was to evaluate the antiangiogenic efficacy of YC-1 [3-(5'-hydroxymethyl-2'-furyl)-1-benzyl indazole] in well characterized in vitro and in vivo systems. YC-1 inhibited the ability of vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) in a dose-dependent manner to induce proliferation, migration, and tube formation in human umbilical vascular endothelial cells; these outcomes were evaluated using [3H]thymidine incorporation, transwell chamber, and Matrigel-coated slide assays, respectively. YC-1 inhibited VEGF- and bFGF-induced p42/p44 mitogen-activated protein kinase and Akt phosphorylation as well as protein kinase C alpha translocation using Western blot analysis. The effect of YC-1 on angiogenesis in vivo was evaluated using the mouse Matrigel implant model. YC-1 administered orally in doses of 1 to 100 mg/kg/day inhibited VEGF- and bFGF-induced neovascularization in a dose-dependent manner over 7 days. These results indicate that YC-1 has antiangiogenic activity at very low doses. Moreover, in transplantable murine tumor models, YC-1 administered orally displayed a high degree of antitumor activity (treatment-to-control life span ratio > 175%) without cytotoxicity. YC-1 may be useful for treating angiogenesis-dependent human diseases such as cancer.
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http://dx.doi.org/10.1124/jpet.105.085126DOI Listing
July 2005