Browsing by Author "Shen T.-L."

Background: Adiponectin (ADN) is an adipokine derived from adipocytes. It binds to adiponectin receptor 1 and 2 (AdipoR1 and R2) to exert its function in regulating whole-body energy homeostasis and inflammatory responses. However, the role of ADN-AdipoR1 signaling in intestinal inflammation is controversial, and its role in the regulation of neutrophils is still unclear. Our goal was to clarify the role of AdipoR1 signaling in colitis and the effects on neutrophils. Methods: We generated porcine AdipoR1 transgenic mice (pAdipoR1 mice) and induced murine colitis using dextran sulfate sodium (DSS) to study the potential role of AdipoR1 in inflammatory bowel disease. We also treated a THP-1 macrophage and a HT-29 colon epithelial cell line with ADN recombinant protein to study the effects of ADN on inflammation. Results: After inducing murine colitis, pAdipoR1 mice developed more severe symptoms than wild-type (WT) mice. Treatment with ADN increased the expression of pro-inflammatory factors in THP-1 and HT-29 cells. Moreover, we also observed that the expression of cyclooxygenase2 (cox2), neutrophil chemokines (CXCL1, CXCL2 and CXCL5), and the infiltration of neutrophils were increased in the colon of pAdipoR1 mice. Conclusions: Our study showed that ADN-AdipoR1 signaling exacerbated colonic inflammation through two possible mechanisms. First, ADN-AdipoR1 signaling increased pro-inflammatory factors. Second, AdipoR1 enhanced neutrophil chemokine expression and recruited neutrophils into the colonic tissue to increase inflammation. ? 2018 The Author(s).

Aims: Bortezomib is a potent proteasome inhibitor currently used to treat various malignancies with promising results. To explore the role of bortezomib in reducing cancer cell migration and inducing apoptosis, we evaluated the effects of bortezomib on the expression of focal adhesion kinase (FAK). Main methods: Various types of cancer cells including lung cancer A549, H1299; a breast cancer MCF7; a hepatocellular carcinoma Huh7, and a tongue squamous cell carcinoma SCC-25 were treated with different concentrations of bortezomib or MG-132 as indicated for 24. h. Protein and mRNA levels were determined by Western blotting and real-time PCR. Apoptosis was analyzed by caspase 3 cleavage and activity. FAK promoter and NFκB binding activities were measured by luciferase-reporter method. NFκB subunit p65 binding capacity was determined by electrophoretic mobility shift assay (EMSA) and chromatin immunoprecipitation (ChIP) analysis. Key findings: Both bortezomib and another proteasome inhibitor, MG-132, significantly reduced FAK expression, suppressed cancer cell migration and increased cell apoptosis. Results of real-time PCR and promoter activity assay revealed that bortezomib decreased FAK expression through transcriptional inactivation. Results of FAK promoter activity and ChIP assays in A549 and H1299 cells indicated that bortezomib suppressed FAK activity through a p53-independent pathway. Furthermore, reduction of NFκB binding capacity demonstrated by EMSA and ChIP assay suggested that NFκB plays an important role in bortezomib suppressing FAK expression. Significance: These results suggested that FAK is downregulated by bortezomib through a proteasome-dependent NFκB inhibitory mechanism. Thus, FAK could be a potential molecular target of bortezomib for therapeutic strategy. ? 2009 Elsevier Inc.

Changes in carbohydrates on the cell surface are associated with tumor malignancy. The mucin-type core 2 β-1,6-N-acetylglucosaminyltransferase (C2GnT-M) is highly expressed in the gastrointestinal tract and catalyses the formation of core 2, core 4, and blood group I branches on O-glycans. In the present study, we evaluated the role of C2GnT-M in colorectal cancer. C2GnT-M downexpression was observed in 73.6% of the primary tumors from colorectal cancer patients (39 of 53) analysed by cancer profiling array. Consistently, the majority of colon cancer cell lines and primary colon tumors expressed lower levels of C2GnT-M than did normal colon tissues by RT-PCR. HCT116 cells stably transfected with C2GnT-M inhibited expression of the core 1 structure, Galβ1,3GalNAcα1-Ser/Thr, on the cell surface. Moreover, C2GnT-M expression suppressed cell adhesion, motility, and invasion as well as colony formation ability. The growth of C2GnT-M-transfected HCT116 and SW480 cells was dramatically suppressed, and the cell death induced by C2GnT-M was demonstrated by an increase in the annexin V-positive cells. Interestingly, C2GnT-M inhibited cell adhesion to collagen IV and fibronectin, and decreased tyrosine phosphorylation of paxillin, indicating that the changes in cancer behavior may be partly mediated by integrin-signaling pathways. Tumor growth in vivo was also significantly suppressed by C2GnT-M in the xenografts of nude mice. These results demonstrate that C2GnT-M is frequently downregulated in colorectal cancer and suppresses colon cancer cell growth. ? 2006 Nature Publishing Group All rights reserved.

Co-amplification and co-overexpression of ErbB2 and Grb7 are frequently found in various cancers, including breast cancer. Biochemical and functional correlations of the two molecules have identified Grb7 to be a pivotal mediator downstream of ErbB2-mediated oncogenesis. However, it remains largely unknown how Grb7 is involve in the ErbB2-mediated tumorigenesis. In this study, we show that Grb7-mediated cell proliferation and growth are essential for the tumorigenesis that occurs in ErbB2-Grb7-overexpressing breast cancer cells. Intrinsically, EGF-induced de novo Grb7 tyrosine phosphorylation/activation recruits and activates Ras-GTPases and subsequently promotes the phosphorylation of ERK1/2, thereby stimulating tumor growth. Furthermore, we also found the anti-tumor effect could be synergized by co-treatment with Herceptin plus Grb7 knockdown in Sk-Br3 breast cancer cells. Our findings illustrate an underlying mechanism by which Grb7 promotes tumorigenesis through the formation of a novel EGFR-Grb7-Ras signaling complex, thereby highlighting the potential strategy of targeting Grb7 as an anti-breast cancer therapy. ? 2010 by The American Society for Biochemistry and Molecular Biology, Inc.

β4 integrin and focal adhesion kinase (FAK) are often associated with a poor prognosis in cancer patients, and their signaling events have recently been linked to malignant outcomes. Here, we demonstrate, for the first time, physical and functional interactions between β4 integrin and FAK that influence breast cancer malignancy. An amino-terminal linker within FAK is essential for its binding with the cytodomain of β4 integrin. Moreover, EGFR/Src-signaling triggers the tyrosine phosphorylation of β4 integrin, which, in turn, recruits FAK to β4 integrin and leads to FAK activation and signaling. Upon disruption of the β4 integrin/FAK complex, tumorigenesis and metastasis in triple-negative breast cancer were markedly reduced. Importantly, the concomitant overexpression of β4 integrin and FAK significantly correlates with malignant potential in patients with triple-negative breast cancer. This study describes a pro-metastatic EGFR/Src-dependent β4 integrin/FAK complex that is involved in breast cancer malignancy and is a novel therapeutic target for triple-negative breast cancer. ? 2015 Macmillan Publishers Limited.

The substantial merit of Cordyceps s.l. spp. in terms of medicinal benefits is largely appreciated. Nevertheless, only few studies have characterized and examined the clinical complications of the use of health tonics containing these species. Here, we epitypified C. formosana isolates that were collected and characterized as Ophiocordyceps formosana based on morphological characteristics, molecular phylogenetic analyses, and metabolite profiling. Thus, we renamed and transferred C. formosana to the new protologue Ophiocordyceps formosana (Kobayasi & Shimizu) Wang, Tsai, Tzean & Shen comb. nov. Additionally, the pharmacological potential of O. formosana was evaluated based on the hot-water extract from its mycelium. The relative amounts of the known bioactive ingredients that are unique to Cordyceps s.l. species in O. formosana were found to be similar to the amounts in O. sinensis and C. militaris, indicating the potential applicability of O. formosana for pharmacological uses. Additionally, we found that O. formosana exhibited antioxidation activities in vitro and in vivo that were similar to those of O. sinensis and C. militaris. Furthermore, O. formosana also displayed conspicuously effective antitumor activity compared with the tested Cordyceps s.l. species. Intrinsically, O. formosana exhibited less toxicity than the other Cordyceps species. Together, our data suggest that the metabolites of O. formosana may play active roles in complementary medicine. ? 2015 Yen-Wen Wang et al.

Cordyceps militaris is a traditional Chinese medicine frequently used for tonic and therapeutic purposes. Reports from our laboratory and others have demonstrated that extracts of the cultivated fruiting bodies of C. militaris (CM) exhibit a potent cytotoxic effect against many cancer cell lines, especially human leukemia cells. Here, we further investigated the underlying mechanism through which CM is cytotoxic to cancer cells. The CM-mediated induction of PARP cleavage and its related DNA damage signal (γH2AX) was diminished by caspase inhibitor I. In contrast, a ROS scavenger failed to prevent CM-mediated leukemia cell death. Moreover, two signaling molecules, AKT and p38 MAPK, were activated during the course of apoptosis induction. Employing MTT analysis, we found that a p38 MAPK inhibitor but not an AKT inhibitor could rescue cells from CM-mediated cell death, as well as inhibit the cleavage of PARP, formation of apoptotic bodies and up-regulation of the γH2AX signal. These results suggest that CM-mediated leukemia cell death occurs through the activation of the p38 MAPK pathway, indicating its potential therapeutic effects against human leukemia. ? 2015 World Scientific Publishing Company & Institute for Advanced Research in Asian Science and Medicine.

Aims: The results of our earlier studies suggested that 14-3-3ε is involved in cancer cell survival and growth. However, it is not clear whether 14-3-3ε plays a role in tumour metastasis and patient outcome. The aim of this study was to determine whether 14-3-3ε is a marker for predicting hepatocellular carcinoma (HCC) metastasis and survival. Methods and results: One hundred and fourteen patients with tissue-diagnosed primary HCC were followed for an average of 58.6months. 14-3-3ε in liver tissues was analysed by immunohistochemistry, and quantified by a Quick score system. Correlation of 14-3-3ε with patient survival and metastasis was analysed with a Wilcoxon signed rank test, Kaplan-Meier survival curves, and Cox proportional hazard regression. Seventy-one of 114 patients (62.3%) had a significant increase of 14-3-3ε expression in HCC tissues, whereas normal tissues expressed weak or undetectable 14-3-3ε. Elevated 14-3-3ε expression was significantly associated with shortened overall survival and progression-free survival. Furthermore, 14-3-3ε overexpression increased the risk of metastasis 4.6-fold. Conclusions: Overexpression of 14-3-3ε in primary HCC tissues predicts a high risk of extrahepatic metastasis and worse survival, and is a potential therapeutic target. ? 2011 Blackwell Publishing Limited.

Cordyceps militaris is a well-known Chinese traditional medicinal mushroom frequently used for tonics and recently of a potential interest for cancer intervention. Here, we explored the cancer cell killing activity of the hot water extracts of C. militaris cultured mycelia (CMMY) and cultivated fruiting bodies (CMFB). We found that CMFBexhibited a greater cytotoxic effect against various cancer cells over CMMY. Apoptotic phenotypes including apoptotic body formation, DNA laddering, caspase 3 activation and cleavage of PARP proteins were induced by CMFBtreatment but only slightly induced by same concentration of CMMYtreatment in human HL-60 leukemia cells. Cordycepin in CMFB(10.47 mg/g) is significantly higher (?15.2 times) than that of CMMY(0.69 mg/g). Using isobolographic analysis, the synergy of cytotoxicity was observed across different combined concentrations of CMMYand cordycepin. By complementing cordycepin into CMMYto the level comparable with CMFB, we observed that CMMY(500 μg/ml) with cordycepin (4.8 μg/ml) induced apoptosis to a level similar to that induced by CMFB(500 μg/ml). Together, our results suggest that cordycepin possesses a synergistic cytotoxic effect with Cordyceps militaris-mediated apoptosis in human leukemia cells and therefore explaining a better anti-proliferating activity of CMFBover CMMY. ? 2014 Elsevier GmbH.

Aims: Both cancer-suppressing and cancer-promoting properties of reactive nitrogen and oxygen species (RNOS) have been suggested to play a role in tumor pathology, particularly those activities associated with chronic inflammation. Here, we address the impact of nitric oxide (NO) on the induction of DNA damage and genome instability with a specific focus on the involvement of topoisomerase II (TOP2). We also investigate the contribution of NO to the formation of skin melanoma in mice. Results: Similar to the TOP2-targeting drug, etoposide (VP-16), the NO-donor, S-nitrosoglutathione (GSNO), induces skin melanomas formation in 7,12-dimethyl-benz[a]anthracene (DMBA)-initiated mice. To explore the mechanism(s) underlying this NO-induced tumorigenesis, we use a co-culture model system to demonstrate that inflamed macrophages with inducible NO synthase (iNOS) expression cause γ-H2AX activation, p53 phosphorylation, and chromosome DNA breaks in the target cells. Inhibitor experiments revealed that NO and TOP2 isozymes are responsible for the above described cellular phenotypes. Notably, NO, unlike VP-16, preferentially induces the formation of TOP2β cleavable complexes (TOP2βcc) in cells. Moreover, GSNO induced TOP2-dependent DNA sequence rearrangements and cytotoxicity. Furthermore, the incidences of GSNO-and VP-16-induced skin melanomas were also observed to be lower in the skin-specific top2β-knockout mice. Our results suggest that TOP2 isozymes contribute to NO-induced mutagenesis and subsequent cancer development during chronic inflammation. Innovation and Conclusions: We provide the first experimental evidence for the functional role of TOP2 in NO-caused DNA damage, mutagenesis, and carcinogenesis. Notably, these studies contribute to our molecular understanding of the cancer-promoting actions of RNOS during chronic inflammation. Antioxid. Redox Signal. 18, 1129-1140. ? 2013, Mary Ann Liebert, Inc.