Qinglong Guo

China Pharmaceutical University, Nan-ching-hsü, Jiangxi Sheng, China

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Publications (120)409.03 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Wogonoside, a main flavonoid component derived from the root of Scutellaria baicalensis Georgi, has been reported to have anti-angiogenesis and anti-leukemia activities. However, whether it can inhibit tumor angiogenesis is unclear. In this study, we investigate the inhibitory effect of wogonoside on angiogenesis in breast cancer and its underlying mechanisms. ELISA assay shows that wogonoside (25, 50, and 100 µM) decreases the secretion of VEGF in MCF-7 cells by 30.0%, 35.4%, and 40.1%, respectively. We find it inhibits angiogenesis induced by the conditioned media from MCF-7 cells in vitro and in vivo by migration, tube formation, rat aortic ring, and chicken chorioallantoic membrane (CAM) assay. Meanwhile, wogonoside can inhibit the growth and angiogenesis of MCF-7 cells xenografts in nude mice. The reduction of tumor weight can be found both in wogonoside (80 mg/kg) and bevacizumab (20 mg/kg) treated group, and the tumor inhibition rate is 42.1% and 48.7%, respectively. In addition, mechanistic studies demonstrate that wogonoside suppresses the activation of Wnt/β-catenin pathway in MCF-7 cells. Wogonoside (100 µM) decreases the intracellular level of Wnt3a, increases the expression of GSK-3β, AXIN, and promotes the phosphorylation of β-catenin for proteasome degradation significantly. Furthermore, the nuclear accumulation of β-catenin and the DNA-binding activity of β-catenin/TCF/Lef complex are inhibited by 49.2% and 28.7%, respectively, when treated with 100 µM wogonoside. Taken together, our findings demonstrate that wogonoside is a potential inhibitor of tumor angiogenesis and can be developed as a therapeutic agent for breast cancer. © 2015 Wiley Periodicals, Inc.
    Molecular Carcinogenesis 09/2015; DOI:10.1002/mc.22412 · 4.81 Impact Factor
  • Yuxin Zhou · Na Lu · Chen Qiao · Ting Ni · Zhiyu Li · Boyang Yu · Qinglong Guo · Libin Wei
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    ABSTRACT: In this study, the anticancer effect of a newly synthesized flavonoid FV-429, against human breast cancer MDA-MB-231 cells, and the underlying mechanisms were investigated. FV-429 triggered the apoptosis and simultaneously inhibited the glycolysis of MDA-MB-231 cells. Both the HK II activity and its level in mitochondria were significantly down regulated by FV-429. Moreover, FV-429 weakened the interaction between HKII and VDAC, stimulated the detachment of HK II from the mitochondria, and resulted in the opening of the mitochondrial permeability transition pores. Thus FV-429 induced the mitochondrial-mediated apoptosis, showing increased Bax/Bcl-2 ratio, loss of mitochondrial membrane potential (MMP) and activation of caspase-3 and -9, cytochrome c (Cyt c) release, and apoptosis inducing factor (AIF) transposition. Further research revealed that the phosphorylation of mitochondrial HKII via Akt was responsible for the dissociation of HKII and the decreased HKII activity induced by FV-429. Taken together, FV-429 inhibited the phosphorylation of HKII, down-regulated its activity, and stimulated the release of HKII from the mitochondria, resulting the inhibited glycolysis and mitochondrial-mediated apoptosis. The studies provide a molecular basis for the development of flavonoid compounds as novel anticancer agents for breast cancer. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.
    Molecular Carcinogenesis 08/2015; DOI:10.1002/mc.22374 · 4.81 Impact Factor
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    ABSTRACT: GL-V9, a new synthesized flavonoid derivative, has been reported to possess anti-cancer properties in our previous studies. Uncontrolled overproduction of reactive oxygen species (ROS) has been implicated in oxidative damage of inflammatory bowel disease (IBD). In this study, we aimed to investigate the protective effect of GL-V9 against dextran sulfate sodium (DSS)-induced colitis. GL-V9 attenuated DSS-induced body weight loss, colon length shortening and colonic pathological damage. GL-V9 also inhibited inflammatory cells infiltration and decreased myeloperoxidase (MPO) and inducible nitric oxide synthase (iNOS) activities. Moreover, GL-V9 inhibited ROS and malondialdehyde (MDA) generation, but enhanced superoxide dismutase (SOD), glutathione (GSH) and total antioxidant capacity. GL-V9 reduced pro-inflammatory cytokines production in serum and colon as well. Mechanically, GL-V9 could increase Trx-1 via activation of AMPK/FOXO3a to suppress DSS-induced colonic oxidative stress. Furthermore, GL-V9 decreased pro-inflammatory cytokines and ROS production and increased the antioxidant defenses in the mouse macrophage cells RAW264.7 by promoting Trx-1 expression. In conclusion, our study demonstrated that GL-V9 attenuated DSS-induced colitis against oxidative stress by up-regulating Trx-1 via activation of AMPK/FOXO3a pathway, suggesting that GL-V9 might be a potential effective drug for colitis.
    Oncotarget 07/2015; 6(28). DOI:10.18632/oncotarget.4657 · 6.36 Impact Factor
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    ABSTRACT: In this study, we aimed to investigate the antitumor effect of LYG-202, a newly synthesized piperazine-substituted derivative of flavonoid on human breast cancer cells and illustrate the potential mechanisms. LYG-202 induced apoptosis in MCF-7, MDA-MB-231 and MDA-MB-435 cells. LYG-202 triggered the activation of mitochondrial apoptotic pathway through multiple steps: increasing Bax/Bcl-2 ratio, decreasing mitochondrial membrane potential (ΔΨ m ), activating caspase-9 and caspase-3, inducing cleavage of poly(ADP-ribose) polymerase, cytochrome c release and apoptosis-inducing factor translocation. Furthermore, LYG-202 inhibited cell cycle progression at the G1/S transition via targeting Cyclin D, CDK4 and p21(Waf1/Cip1). Additionally, LYG-202 increased the generation of intracellular ROS. N-Acetyl cysteine, an antioxidant, reversed LYG-202-induced apoptosis suggesting that LYG-202 induces apoptosis by accelerating ROS generation. Further, we found that LYG-202 deactivated the PI3K/Akt pathway, activated Bad phosphorylation, increased Cyclin D and Bcl-xL expression, and inhibited NF-κB nuclear translocation. Activation of PI3K/Akt pathway by IGF-1 attenuated LYG-202-induced apoptosis and cell cycle arrest. Our in vivo study showed that LYG-202 exhibited a potential antitumor effect in nude mice inoculated with MCF-7 tumor through similar mechanisms identified in cultured cells. In summary, our results demonstrated that LYG-202 induced apoptosis and cell cycle arrest via targeting PI3K/Akt pathway, indicating that LYG-202 is a potential anticancer agent for breast cancer.
    Apoptosis 07/2015; 20(9). DOI:10.1007/s10495-015-1145-x · 3.69 Impact Factor
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    ABSTRACT: GATA-1, a zinc finger transcription factor, has been demonstrated to play a key role in the progression of leukemia. In this study, we investigate the effects of wogonoside, a naturally bioactive flavonoid derived from Scutellaria baicalensis Georgi, on cell growth and cell cycle in chronic myeloid leukemia (CML) cells, and uncover its underlying mechanisms. The experimental design comprised CML cell lines K562, imatinib-resistant K562 (K562r) cells, and primary CML cells, treated in vitro or in vivo, respectively, with wogonoside; growth and cell cycle were then evaluated. We found that wogonoside could induce growth inhibition and G0/G1 cell cycle arrest in both normal and K562r cells. Wogonoside promotes the expression of GATA-1 and facilitates the binding to methyl ethyl ketone (MEK) and p21 promoter, thus inhibiting MEK/extracellular signal-regulated kinase signaling and cell cycle checkpoint proteins, including CDK2, CDK4, cyclin A, and cyclin D1, and increasing p21 expression. Furthermore, in vivo studies showed that administration of wogonoside decreased CML cells and prolonged survival in NOD/SCID mice with CML cell xenografts. In conclusion, these results clearly revealed the inhibitory effect of wogonoside on the growth in CML cells and suggested that wogonoside may act as a promising drug for the treatment of imatinib-resistant CML.
    Archives of Toxicology 06/2015; DOI:10.1007/s00204-015-1552-3 · 5.98 Impact Factor
  • Jie Sun · Fanni Li · Yue Zhao · Li Zhao · Chen Qiao · Zhiyu Li · Qinglong Guo · Na Lu
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    ABSTRACT: Flavonoids and flavonoid derivatives, which have significant biological and pharmacological activities, including antitumor and anti-inflammatory activities, have been widely used in human healthcare. To design a more effective flavonoid antitumor agent, we altered the flavonoid backbone with substitutions of piperazine and methoxy groups to synthesize a novel flavonoid derivative, LZ-207. The anticancer effect of LZ-207 against HCT116 colon cancer cells and the underlying mechanism of this effect were explored in this study. Specifically, LZ-207 exhibited inhibitory effects on growth and viability in several human colon cancer cell lines and induced apoptosis in HCT116 cells both in vitro and in vivo. LZ-207 treatment also suppressed the nuclear translocation of NF-κB and the phosphorylation of IκB and IKKα/β in a dose-dependent manner in both HCT116 cells and human acute monocytic leukemia THP-1 cells. Moreover, LZ-207 also reduced the secretion of the pro-inflammatory cytokine interleukin-6 (IL-6) in LPS-induced THP-1 cells, and this effect was confirmed at the transcriptional level. Furthermore, LZ-207 significantly inhibited HCT116 cell proliferation that was elicited by LPS-induced THP-1 cells in a co-culture system. These findings elucidated some potential molecular mechanisms for preventing inflammation-driven colon cancer using the newly synthesized flavonoid LZ-207 and suggested the possibility of further developing novel therapeutic agents derived from flavonoids.
    PLoS ONE 05/2015; 10(5):e0127282. DOI:10.1371/journal.pone.0127282 · 3.23 Impact Factor
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    ABSTRACT: Wogonin, a naturally occurring monoflavonoid extracted from the root of Scutellaria baicalensis Georgi, has been shown to have anti-inflammatory and anti-tumor activities and inhibits oxidant stress-induced vascular permeability. However, the influence of wogonin on vascular hyperpermeability induced by overabounded inflammatory factors often appears in inflammatory diseases and tumor is not well known. In this study, we evaluate the effects of wogonin on LPS induced vascular permeability in human umbilical vein endothelial cells (HUVECs) and investigate the underlying mechanisms. We find that wogonin suppresses the LPS-stimulated hyperactivity and cytoskeleton remodeling of HUVECs, promotes the expression of junctional proteins including VE-Cadherin, Claudin-5 and ZO-1, as well as inhibits the invasion of MDA-MB-231 across ECs monolayer. Miles vascular permeability assay proves wogonin can restrain the extravasated Evans in vivo. The mechanism studies reveal that the expressions of TLR4, p-PLC, p-MLCK and p-MLC are decreased by wogonin without changing the total steady state protein levels of PLC, MLCK and MLC. Moreover, wogonin can also inhibit KCl-activated MLCK/MLC pathway, and further affect vascular permeability. Significantly, compared with wortmannin, the inhibitor of MLCK/MLC pathway, wogonin exhibits the similar inhibition effects on the expression of p-MLCK, p-MLC and LPS-induced vascular hyperpermeability. Taken together, wogonin can inhibit LPS-induced vascular permeability by suppressing the MLCK/MLC pathway, suggesting a therapeutic potential for the diseases associated with the development of both inflammatory and tumor. Copyright © 2015. Published by Elsevier Inc.
    Vascular Pharmacology 05/2015; 72. DOI:10.1016/j.vph.2015.04.012 · 3.64 Impact Factor
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    Kai Zhao · Yuxin Zhou · Chen Qiao · Ting Ni · Zhiyu Li · Xiaotang Wang · Qinglong Guo · Na Lu · Libin Wei
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    ABSTRACT: p53 plays important roles in regulating the metabolic reprogramming of cancer, such as aerobic glycolysis. Oroxylin A is a natural active flavonoid with strong anticancer effects both in vitro and in vivo. wt-p53 (MCF-7 and HCT116 cells) cancer cells and p53-null H1299 cancer cells were used. The glucose uptake and lactate production were analyzed using Lactic Acid production Detection kit and the Amplex Red Glucose Assay Kit. Then, the protein levels and RNA levels of p53, mouse double minute 2 (MDM2), and p53-targeted glycolytic enzymes were quantified using Western blotting and quantitative polymerase chain reaction (PCR), respectively. Immunoprecipitation were performed to assess the binding between p53, MDM2, and sirtuin-3 (SIRT3), and the deacetylation of phosphatase and tensin homolog (PTEN). Reporter assays were performed to assess the transcriptional activity of PTEN. In vivo, effects of oroxylin A was investigated in nude mice xenograft tumor-inoculated MCF-7 or HCT116 cells. Here, we analyzed the underlying mechanisms that oroxylin A regulated p53 level and glycolytic metabolism in wt-p53 cancer cells, and found that oroxylin A inhibited glycolysis through upregulating p53 level. Oroxylin A did not directly affect the transcription of wt-p53, but suppressed the MDM2-mediated degradation of p53 via downregulating MDM2 transcription in wt-p53 cancer cells. In further studies, we found that oroxylin A induced a reduction in MDM2 transcription by promoting the lipid phosphatase activity of phosphatase and tensin homolog, which was upregulated via sirtuin3-mediated deacetylation. In vivo, oroxylin A inhibited the tumor growth of nude mice-inoculated MCF-7 or HCT116 cells. The expression of MDM2 protein in tumor tissue was downregulated by oroxylin A as well. These results provide a p53-independent mechanism of MDM2 transcription and reveal the potential of oroxylin A on glycolytic regulation in both wt-p53 and mut-p53 cancer cells. The studies have important implications for the investigation on anticancer effects of oroxylin A, and provide the academic basis for the clinical trial of oroxylin A in cancer patients.
    Journal of Hematology & Oncology 04/2015; 8(1):41. DOI:10.1186/s13045-015-0137-1 · 4.81 Impact Factor
  • Libin Wei · Yuxin Zhou · Jing Yao · Chen Qiao · Ting Ni · Ruichen Guo · Qinglong Guo · Na Lu
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    ABSTRACT: Reprogramming energy metabolism, such as enhanced glycolysis, is an Achilles' heel in cancer treatment. Most studies have been performed on isolated cancer cells. Here, we studied the energy-transfer mechanism in inflammatory tumor microenvironment. We found that human THP-1 monocytes took up lactate secreted from tumor cells through monocarboxylate transporter 1. In THP-1 monocytes, the oxidation product of lactate, pyruvate competed with the substrate of proline hydroxylase and inhibited its activity, resulting in the stabilization of HIF-1α under normoxia. Mechanistically, activated hypoxia-inducible factor 1-α in THP-1 monocytes promoted the transcriptions of prostaglandin-endoperoxide synthase 2 and phosphoenolpyruvate carboxykinase, which were the key enzyme of prostaglandin E2 synthesis and gluconeogenesis, respectively, and promote the growth of human colon cancer HCT116 cells. Interestingly, lactate could not accelerate the growth of colon cancer directly in vivo. Instead, the human monocytic cells affected by lactate would play critical roles to 'feed' the colon cancer cells. Thus, recycling of lactate for glucose regeneration was reported in cancer metabolism. The anabolic metabolism of monocytes in inflammatory tumor microenvironment may be a critical event during tumor development, allowing accelerated tumor growth.
    Oncotarget 04/2015; 6(18). DOI:10.18632/oncotarget.3838 · 6.36 Impact Factor
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    Libin Wei · Qinsheng Dai · Yuxin Zhou · Meijuan Zou · Zhiyu Li · Na Lu · Qinglong Guo
    Biochimica et Biophysica Acta (BBA) - General Subjects 04/2015; 1850(4):857. DOI:10.1016/j.bbagen.2014.07.007 · 4.38 Impact Factor
  • Yang Sun · Yue Zhao · Jing Yao · Li Zhao · Zhaoqiu Wu · Yu Wang · Di Pan · Hanchi Miao · Qinglong Guo · Na Lu
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    ABSTRACT: Previous studies have demonstrated that wogonoside, the glucuronide metabolite of wogonin, has anti-inflammatory, anti-angiogenic and anticancer effects. However, the anti-inflammatory mechanism of wogonoside has not been fully elucidated. Recently, NLRP3 inflammasome has been reported to be correlated with inflammatory bowel disease for its ability to induce IL-1β release. Nevertheless, there are few drug candidates targeting NLRP3 inflammasome for this disease. In this study, we investigated the anti-inflammatory effect of wogonoside in dextran sulfate sodium (DSS)-induced murine colitis and further revealed the underlying mechanisms by targeting NF-κB and NLRP3 inflammasome. Wogonoside treatment dose-dependently attenuated DSS-induced body weight loss, colon length shortening, diarrhea and intestinal bleeding. Moreover, wogonoside prevented DSS-induced colonic pathological damage, remarkably inhibited inflammatory cells infiltration and significantly decreased myeloperoxidase (MPO) and inducible nitric oxide synthase (iNOS) activities. The production of pro-inflammatory mediators in serum and colon was also significantly reduced by wogonoside. The underlying mechanisms for the protective effect of wogonoside in DSS-induced colitis may be attributed to its inhibition on NF-κB and NLRP3 inflammasome activation in colons. Furthermore, wogonoside markedly decreased production of IL-1β, TNF-α and IL-6 and suppressed mRNA expression of pro-IL-1β and NLRP3 in phorbol myristate acetate (PMA)-differentiated monocytic THP-1 cells via inhibiting the activation of NF-κB and NLRP3 inflammasome. In conclusion, our study demonstrated that wogonoside may exert its anti-inflammatory effect via dual inhibition of NF-κB and NLRP3 inflammasome, suggesting that wogonoside might be a potential effective drug for inflammatory bowel diseases. Copyright © 2015 Elsevier Inc. All rights reserved.
    Biochemical Pharmacology 02/2015; 94(2). DOI:10.1016/j.bcp.2015.02.002 · 5.01 Impact Factor
  • Li Zhao · Wei Li · Yuxin Zhou · Yi Zhang · Shaoliang Huang · Xuefen Xu · Zhiyu Li · Qinglong Guo
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    ABSTRACT: Microenvironmental hypoxia renders many tumor cells capacity for drug resistance. Thioredoxin (Trx) family members play critical roles in the regulation of cellular redox homeostasis under stressed environment. In this study, we reestablished hypoxia-drug resistance (hypoxia-DR) model using HepG2 cells and discovered that the overexpression and nuclear translocation of thioredoxin-1 (Trx-1) are closely associated with this resistance through regulating metabolism from the oxidative stress response to glycolysis. Intranuclear Trx-1 enhances DNA-binding activity of HIF-1α via its interaction and reducing action with Ref-1, resulting in increased expression of glycolysis-related proteins (PDHK1, HKII and LDHA), glucose uptake, and lactate generation under hypoxia. Meanwhile, we found that GL-V9, a newly synthesized flavonoid derivative, shows reversal abilities on the hypoxia-DR and low toxicities both in vivo and in vitro. GL-V9 could inhibit the expression and nuclear translocation of Trx-1 and then suppress HIF-1α DNA-binding activity via inhibiting Trx-1/Ref-1 axis. As a result of the above, glycolysis was weakened and oxidative phosphorylation was enhanced. Thus, GL-V9 led to increment of intracellular ROS generation and consequently intensified apoptosis induced by DDP. Copyright © 2015 Elsevier Inc. All rights reserved.
    Free Radical Biology and Medicine 02/2015; 82. DOI:10.1016/j.freeradbiomed.2015.01.014 · 5.74 Impact Factor
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    ABSTRACT: Following our previous finding which revealed that FV-429 induces apoptosis in human hepatocellular carcinoma HepG2 cells, in this study, we found that FV-429 could also induce apoptosis in human gastric cancer cells. Firstly, FV-429 inhibited the viability of BGC-823 and MGC-803 cells with IC50 values in the range of 38.10 ± 6.28μM and 31.53 ± 6.84μM for 24 h treatment by MTT-assay. Secondly, FV-429 induced apoptosis in BGC-823 and MGC-803 cells through the mitochondrial-mediated pathway, showing an increase in Bax/Bcl-2 ratios, and caspase-9 activation, without change in caspase-8. Further research revealed that the mitogen-activated protein kinases, including c-Jun N-terminal kinase, extracellular regulated kinase and p38 mitogen-activated protein kinase, could be activated by FV-429-induced high level ROS. Moreover, FV-429 also promoted the ERK2 nuclear translocation, resulting in the co-translocation of p53 to the nucleus and increased transcription of p53-regulated proapoptotic genes. FV-429 significantly inhibited the nude mice xenograft tumors growth of BGC-823 or MGC-803 cells in vivo. This article is protected by copyright. All rights reserved
    Journal of Cellular Biochemistry 02/2015; 116(8). DOI:10.1002/jcb.25118 · 3.26 Impact Factor
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    ABSTRACT: Gambogic acid (GA), a special category of Garcinia xanthones, has attracted great attention owing to its striking bioactivities and unique structure. To further explore its structure-activity relationship, we prepared seven novel oxa-caged Garcinia xanthones that were for the first time varied at the C-2 position of B ring and at the C-21/22 or C-23 position of the prenyl group in the caged scaffold. Some compounds exhibited strong anti-proliferation activities in different cancer cell lines. Particularly, compound 8 showed more potent cytotoxic activity and better selectivity towards the A549 cell line than GA. Oxa-caged xanthones 8 was identified as an A549 cell apoptosis inducer through observations of morphological changes and Annexin-V/PI double-staining assay. Additionally, the structure-activity relationships of these new analogues were discussed.
    Australian Journal of Chemistry 01/2015; 68(6):872. DOI:10.1071/CH14328 · 1.56 Impact Factor
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    ABSTRACT: (±)-Calliviminones A (1) and B (2), two Diels–Alder adducts of polymethylated phloroglucinol and myrcene with unprecedented spiro-[5.5] undecene skeleton, were isolated from the fruits of Callistemon viminalis. Structural elucidation was accomplished by NMR spectra studies, and the biomimetic synthesis of compounds 1 and 2 confirmed the pivotal role of Diels–Alder reaction in the plausible biosynthetic pathway. Compounds 1 and 2 were also the first example of Carbon Diels–Alder adducts between phloroglucinol and terpene. Bioactivity scan indicated that 1 and 2 showed moderate inhibition on NO production on lipopolysaccharide-induced RAW264.7 macrophages.
    Tetrahedron Letters 01/2015; 56(1). DOI:10.1016/j.tetlet.2014.11.075 · 2.38 Impact Factor
  • Yuan Gao · Kai Zhao · Yujie Huang · Yuxin Zhou · Zhiyu Li · Ruichen Guo · Qinglong Guo · Yulin Wu · Na Lu
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    ABSTRACT: Excess or inappropriate angiogenesis occurs in the pathogenesis process of many diseases, such as cancer, wound healing and eye disease, especially angiogenesis stimulated by inflammatory factors contributes to the development of inflammation and cancer. In this study, we investigated the inhibitory effect of LL202, a newly synthesized flavonoid, on LPS-induced angiogenesis and further probed the potential molecular mechanisms by detecting MAPK and NF-κB pathways. We found that LL202 inhibited LPS-induced migration, tube formation of human umbilical vein endothelial cells (HUVECs), and microvessel sprouting from rat aotric ring in vivo. The result of matrigel plug assay and chicken chorioallantoic membrane (CAM) model also revealed that LL202 could inhibit LPS-induced angiogensis in vivo. Western Blot analysis indicated that LL202 could inhibit the expression of LPS acceptor toll-like receptor 4 (TLR4) and its downstream protein kinases, including the phosphorylation of JNK, p38, ERK, IKK and IκBα. Moreover, LL202 inhibited the nuclear translocation of NF-κB and its binding to DNA. Accordingly, the expression of vascular endothelial growth factor (VEGF) was down-regulated at the level of gene transcription, which is a crucial mediator in angiogenesis. Taken together, LL202 could suppress LPS-induced angiogenesis with the intervention of LPS/TLR4 signaling.
    RSC Advances 10/2014; 4(110). DOI:10.1039/C4RA08691K · 3.84 Impact Factor
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    ABSTRACT: Constitutive NF-E2-related factor 2(Nrf2) activation has been recently reported to play a pivotal role in enhancing cell survival and resistance to anticancer drugs in many tumors. Previously, much effort has been devoted to the investigation of blocking Nrf2 function in cultured cells and cancer tissues, but few research has been undertaken to evaluate the precise mechanism of flavonoids-induced sensitivity by inhibiting Nrf2. In this study, we investaged the reversal effect of Wogonin, a flavonoid isolated from the root of Scutellaria baicalensis Georgi, in resistant human myelogenous leukemia. Data indicated that Wogonin had strong reversal potency by inhibiting functional activity and expression of MRP1 at both protein and mRNA in adriamycin(ADR)-induced resistant human myelogenous leukemia K562/A02 cells. Consequently, the inhibition of MRP1 by Wogonin was dependent on Nrf2 through the decreased binding ability of Nrf2 to antioxidant response element(ARE). Further research revealed Wogonin modulated Nrf2 through the reduction of Nrf2mRNA at transcriptional processes rather than RNA degradation, which is regulated by the PI3K/Akt pathway. Moreover, DNA-PKcs was found to be involved in the Wogonin-induced downregulation of Nrf2 mRNA at transcriptional levels. In summary, these results clearly demonstrated the effectiveness of using Wogonin via inhibiting Nrf2 to combat chemoresistance and suggested that Wogonin can be developed into an efficient natural sensitizer for resistant human myelogenous leukemia.
    Biochemical Pharmacology 09/2014; 92(2). DOI:10.1016/j.bcp.2014.09.008 · 5.01 Impact Factor
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    ABSTRACT: Oroxylin A is a flavonoid extracted from the root of Scutellaria baicalensis Georgi. Our previous research demonstrated that oroxylin A have various anti-tumor effects including apoptosis, cell cycle arrest, drug-resistant reversion and others. This paper explores the mechanism how oroxylin A induce apoptosis by regulating uncoupling protein 2 (UCP2) in human colon cancer cells. We found that the inhibition of UCP2 by UCP2 siRNA significantly increased the sensitivity of cells to drugs, reactive oxygen species (ROS) generation and the opening of mitochondrial permeability transition pore (MPTP) of CaCo-2 cells. We also found that UCP2 inhibition could lead to ROS-mediated MPTP activation. Furthermore, we demonstrated that oroxylin A triggered MPTP-dependent pro-apoptotic protein release from mitochondria to matrix and then induced apoptotic cascade by inhibiting UCP2. Intriguingly, the inhibition of UCP2 by oroxylin A was able to block Bcl-2 translocation to the mitochondria, keeping MPTP at open-state. In conclusion, we have demonstrate that UCP2 play a key role in mitochondrial apoptotic pathway; UCP2's inhibition by oroxylin A triggers the MPTP opening, and promotes the apoptosis in CaCo-2 cells. J. Cell. Physiol. © 2014 Wiley Periodicals, Inc.
    Journal of Cellular Physiology 09/2014; 230(5). DOI:10.1002/jcp.24833 · 3.84 Impact Factor
  • Meijuan Zou · Chen Hu · Qidong You · Aixia Zhang · Xuerong Wang · Qinglong Guo
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    ABSTRACT: Autophagy is a tightly-regulated catabolic pathway involving degradation of cellular proteins, cytoplasm and organelles. Recent evidence suggests that autophagy plays a potential role in cell death as a tumor suppressor and that its induction especially in combination with apoptosis could be beneficial. It remains unclear if all cancer cells behave the same mechanism when autophagy is induced. Although mammalian target of rapamycin (mTOR) is well known as a negative regulator of autophagy, the relationship between signal transducer and activator of transcription 3 (STAT3) and autophagy has not yet been investigated. Oroxylin A, a natural mono-flavonoid extracted from Scutellariae radix, is a promising therapeutic agent for treating multiple cancers. Here we investigated the mechanism underlying the effect of oroxylin A on malignant glioma cells. We showed that oroxylin A inhibited the proliferation of malignant glioma cells by inducing autophagy in a dose- and time-dependent manner. Oroxylin A treatment inhibits the AKT and ERK activation and the downstream phosphorylation level of mTOR and STAT3. In addition, oroxylin A treatment decreases the expression of Notch-1 and myeloid cell leukemia-1 (Mcl-1) but upregulates Beclin 1, the key autophagy-related protein. 3-MA (autophagy inhibitor) or knockdown of Beclin 1 partially can rescue cells from oroxylin A-induced autophagic cell death. In contrast, knockdown of STAT3 aggravates oroxylin A-induced autophagic cell death. Our data reveal an important role of autophagy in enhancing cell death induced by oroxylin A and conclude that oroxylin A exerts anti-malignant glioma proficiency by inducing autophagy via the ERK/AKT-mTOR-STAT3-Notch signaling cascade. © 2014 Wiley Periodicals, Inc.
    Molecular Carcinogenesis 09/2014; DOI:10.1002/mc.22212 · 4.81 Impact Factor
  • Hui Hui · Hao Yang · Qinsheng Dai · Qian Wang · Jing Yao · Kai Zhao · Qinglong Guo · Na Lu
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    ABSTRACT: Production of IL-6 constituted the major cause of death in the ATRA trial called retinoic acid syndrome (RAS). LAP and LIP are active and inactive isoforms of C/EBPβ, respectively. Inactive LIP dimerized with LAP to eliminate its activity. Following treatment with ATRA, CHOP expression was increased and dimerized with LIP more preferentially than LAP to rescue function of LAP. Oroxylin A has been reported to activate CHOP, a key mediator of unfolded protein response (UPR) pathway, and resulted in apoptosis. Interestingly, we found that low concentration of oroxylin A (≦40μM) showed no apoptosis effect on NB4 and HL-60 cells and decreased the CHOP protein level via promoting its degradation. MG132 was utilized to conform the effect of oroxylin A on degrading CHOP. Our results showed that oroxylin A decreased the level of IL-6 secretion of NB4 cells with or without ATRA treatment while the effect was eliminated by C/EBPβ siRNA. We conclude that oroxylin A possessed abilities of inhibiting the ATRA-induced IL-6 production via modulation of LAP/LIP/CHOP in leukemia cell lines, which could providing a therapeutic strategy for RAS.
    Gene 09/2014; 551(2). DOI:10.1016/j.gene.2014.08.061 · 2.14 Impact Factor

Publication Stats

1k Citations
409.03 Total Impact Points


  • 2006–2015
    • China Pharmaceutical University
      • • Department of Natural Medicinal Chemistry
      • • Jiangsu Key Laboratory of Carcinogenesis and Intervention
      • • Department of Physiology
      Nan-ching-hsü, Jiangxi Sheng, China
  • 2011
    • Shenyang Pharmaceutical University
      Feng-t’ien, Liaoning, China
  • 2009
    • Government of the People's Republic of China
      Peping, Beijing, China
  • 2008
    • Society for Experimental Biology & Medicine
      Society Hill, New Jersey, United States