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Sample records for phosphorylation promotes cholangiocarcinoma

  1. Nicotine Promotes Cholangiocarcinoma Growth in Xenograft Mice.

    PubMed

    Martínez, Allyson K; Jensen, Kendal; Hall, Chad; O'Brien, April; Ehrlich, Laurent; White, Tori; Meng, Fanyin; Zhou, Tianhao; Greene, John; Bernuzzi, Francesca; Invernizzi, Pietro; Dostal, David E; Lairmore, Terry; Alpini, Gianfranco; Glaser, Shannon S

    2017-05-01

    Nicotine, the main addictive substance in tobacco, is known to play a role in the development and/or progression of a number of malignant tumors. However, nicotine's involvement in the pathogenesis of cholangiocarcinoma is controversial. Therefore, we studied the effects of nicotine on the growth of cholangiocarcinoma cells in vitro and the progression of cholangiocarcinoma in a mouse xenograft model. The predominant subunit responsible for nicotine-mediated proliferation in normal and cancer cells, the α7 nicotinic acetylcholine receptor (α7-nAChR), was more highly expressed in human cholangiocarcinoma cell lines compared with normal human cholangiocytes. Nicotine also stimulated the proliferation of cholangiocarcinoma cell lines and promoted α7-nAChR-dependent activation of proliferation and phosphorylation of extracellular-regulated kinase in Mz-ChA-1 cells. In addition, nicotine and PNU282987 (α7-nAChR agonist) accelerated the growth of the cholangiocarcinoma tumors in our xenograft mouse model and increased fibrosis, proliferation of the tumor cells, and phosphorylation of extracellular-regulated kinase activation. Finally, α7-nAChR was expressed at significantly higher levels in human cholangiocarcinoma compared with normal human control liver samples. Taken together, results of this study suggest that nicotine acts through α7-nAChR and plays a novel role in the pathogenesis of cholangiocarcinoma. Furthermore, nicotine may act as a mitogen in cholestatic liver disease processes, thereby facilitating malignant transformation. Copyright © 2017 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

  2. Cholangiocarcinoma

    PubMed Central

    Razumilava, Nataliya; Gores, Gregory J

    2014-01-01

    Cholangiocarcinoma represents a diverse group of epithelial cancers united by late diagnosis and poor outcomes. Specific diagnostic and therapeutic approaches are undertaken for cholangiocarcinomas of different anatomical locations (intrahepatic, perihilar, and distal). Mixed hepatocellular cholangiocarcinomas have emerged as a distinct subtype of primary liver cancer. Clinicians need to be aware of intrahepatic cholangiocarcinomas arising in cirrhosis and properly assess liver masses in this setting for cholangiocarcinoma. Management of biliary obstruction is obligatory in perihilar cholangiocarcinoma, and advanced cytological tests such as fluorescence in-situ hybridisation for aneusomy are helpful in the diagnosis. Liver transplantation is a curative option for selected patients with perihilar but not with intrahepatic or distal cholangiocarcinoma. International efforts of clinicians and scientists are helping to identify the genetic drivers of cholangiocarcinoma progression, which will unveil early diagnostic markers and direct development of individualised therapies. PMID:24581682

  3. CXCL7 promotes proliferation and invasion of cholangiocarcinoma cells.

    PubMed

    Guo, Qian; Jian, Zhixiang; Jia, Baoqing; Chang, Liang

    2017-02-01

    CXCL7 is an important chemoattractant cytokine, which signals through binding to its receptor CXCR2. Recent studies have demonstrated that the CXCL7/CXCR2 signaling plays a promoting role in several common malignancies, including lung, renal, colon, and breast cancer. However, the regulatory role of CXCL7, in cholangiocarcinoma, as well as the underlying mechanism, has not been previously reported. Herein, we found more positive expression of CXCL7 in cholangiocarcinoma tissues compared to adjacent non-tumor tissues. High CXCL7 expression was significantly correlated with poor differentiation, lymph node metastasis, vascular invasion and advanced clinical stage, but was not associated with age, gender, or tumor size. Besides, the expression of CXCL7 was significantly associated with the Ki67 expression, but not associated with CA199, AFP, or P53 expression in cholangiocarcinoma. Moreover, the overall survival of cholangiocarcinoma patients with high CXCL7 expression was significantly shorter than those with low CXCL7 expression. In vitro study indicated that CXCL7 and CXCR2 were also positively expressed in several common cholangiocarcinoma cell lines, including HuCCT1, HuH28, QBC939, EGI-1, OZ and WITT. SiRNA-induced inhibition of CXCL7 significantly reduced the proliferation and invasion of QBC939 cells. On the contrary, overexpression of CXCL7 markedly promoted these malignant phenotypes of QBC939 cells. Of note, the conditioned medium of CXCL7-overexpresing human hepatic stellate cells could also promote the proliferation and invasion of QBC939 cells, suggesting that CXCL7 may also play an oncogenic role in cholangiocarcinoma in a paracrine-dependent manner, not only in an autocrine-dependent manner. Molecular assay data suggested that the AKT signaling pathway was involved in the CXCL7-mediated malignant phenotypes of QBC939 cells. In summary, our study suggests that CXCL7 plays a promoting role in regulating the growth and metastasis of cholangiocarcinoma.

  4. Autocrine and Paracrine Mechanisms Promoting Chemoresistance in Cholangiocarcinoma

    PubMed Central

    Cadamuro, Massimiliano; Brivio, Simone; Spirli, Carlo; Joplin, Ruth E.; Strazzabosco, Mario; Fabris, Luca

    2017-01-01

    Resistance to conventional chemotherapeutic agents, a typical feature of cholangiocarcinoma, prevents the efficacy of the therapeutic arsenal usually used to combat malignancy in humans. Mechanisms of chemoresistance by neoplastic cholangiocytes include evasion of drug-induced apoptosis mediated by autocrine and paracrine cues released in the tumor microenvironment. Here, recent evidence regarding molecular mechanisms of chemoresistance is reviewed, as well as associations between well-developed chemoresistance and activation of the cancer stem cell compartment. It is concluded that improved understanding of the complex interplay between apoptosis signaling and the promotion of cell survival represent potentially productive areas for active investigation, with the ultimate aim of encouraging future studies to unveil new, effective strategies able to overcome current limitations on treatment. PMID:28098760

  5. Decreased roundabout 1 expression promotes development of intrahepatic cholangiocarcinoma.

    PubMed

    Mano, Yohei; Aishima, Shinichi; Fukuhara, Takasuke; Tanaka, Yuki; Kubo, Yuichiro; Motomura, Takashi; Toshima, Takeo; Iguchi, Tomohiro; Shirabe, Ken; Maehara, Yoshihiko; Oda, Yoshinao

    2013-11-01

    Roundabout 1 (Robo1) is a transmembrane receptor of the immunoglobulin family. Slit2 is one of its ligands. The function of Slit2/Robo1 signaling in the development of intrahepatic cholangiocarcinoma (ICC) remains to be elucidated. We examined the immunohistochemical expression of Robo1 and Slit2 and their clinicopathologic implications in 132 cases of ICC. Also, small interfering RNA of Robo1 was transfected into a high-expression ICC cell line, and a Robo1 vector was transfected into a low-Robo1 expression ICC cell line. The effect of Robo1 suppression and overexpression in cell proliferation and migration of cultured ICC cells with Slit2 stimulation was investigated. Immunohistochemical study of ICC in the low-Robo1 expression group showed larger tumors (P = .015), a higher Ki-67 labeling index (P = .021), and low expression of Slit2 (P = .0005). The low-Slit2 expression group frequently showed perineural invasion (P = .036) and lymph node metastases (P = .013). Low Robo1 expression was associated with a poor prognosis (P = .0207). Robo1 suppression in Huh28 cells tended to promote cell proliferation and migration, whereas Robo1 overexpression in RBE cells significantly suppressed cell proliferation and migration. Low Robo1 expression was associated with cell proliferation and migration in ICC and was one of the adverse prognostic factors in patients with these tumors.

  6. STAT3 overexpression promotes metastasis in intrahepatic cholangiocarcinoma and correlates negatively with surgical outcome.

    PubMed

    Yang, Xin-Wei; Li, Liang; Hou, Guo-Jun; Yan, Xin-Zhou; Xu, Qin-Guo; Chen, Lei; Zhang, Bao-Hua; Shen, Feng

    2017-01-31

    Signal transducer and activator of transcription 3 (STAT3) promotes tumor progression in many types of cancer. In this study, we analyzed the prognostic value of this marker in human intrahepatic cholangiocarcinoma (ICC). Using real-time PCR, western blot and immunohistochemistry assays, we found that STAT3 is overexpressed in ICC patients. STAT3 expression correlated with several clinicopathological features, including tumor size, pathological satellite, vascular invasion, undifferentiated-type histology, lymph node metastasis and TNM stage in two independent cohorts of ICC patients. Patients with high STAT3 levels had a poor prognosis in terms of overall survival (OS) and disease-free survival (DFS). Multivariate survival analysis indicated that STAT3 is an independent prognostic factor for OS and DFS. Furthermore, we observed that STAT3 overexpression promotes the invasion, metastasis and proliferation of ICC cells in vitro and in vivo, and also promotes STAT3 phosphorylation. These findings suggest that STAT3 expression correlated negatively with surgical outcome and inhibition of STAT3 expression may constitute a novel target for the treatment of ICC patients.

  7. Fibroblast growth factor receptor 4 promotes progression and correlates to poor prognosis in cholangiocarcinoma

    SciTech Connect

    Xu, Yun-Fei; Yang, Xiao-Qing; Lu, Xiao-Fei; Guo, Sen; Liu, Yi; Iqbal, Mohammad; Ning, Shang-Lei; Yang, Hui; Suo, Ning; Chen, Yu-Xin

    2014-03-28

    Highlights: • FGFR4 is significantly related with N stage in IHCC, with T stage and TNM stage in PHCC. • FGFR4 is an independent prognostic factor in IHCC and PHCC. • FGFR4 promotes proliferation, invasion and EMT in cholangiocarinoma cell lines. • Inhibitor AP24354 can decrease proliferation, invasion and induce apoptosis of CCA. - Abstract: Fibroblast growth factor receptor 4 (FGFR4) is related to poor prognosis of several cancers, but the correlation between FGFR4 expression and cholangiocarcinoma (CCA) has not been well elucidated. We investigated the expression of FGFR4 in 83 intrahepatic cholangiocarcinomas (IHCCs), 75 perihilar cholangiocarcinomas (PHCCs) and 41 distal cholangiocarcinomas (DCCs) by immunohistochemistry (IHC), and subsequently evaluated association of FGFR4 with clinicopathologic parameters and survival rate. The rate of FGFR4 higher expression was 61.4% (51/83) in IHCCs, 53.3% (40/75) in PHCCs and 56.1% (23/41) in DCCs. FGFR4 expression was significantly related to poor prognosis of IHCC (P = 0.002) and PHCC (P = 0.019) with univariate analysis, and also identified as an independent prognostic factor in IHCC (P = 0.045) and PHCC (P = 0.049) with multivariate analysis. Additionally, with functional assays in vitro, we found FGFR4 can induce proliferation, invasion and epithelial–mesenchymal transition (EMT) of CCA cell lines with FGF19 stimulation. Moreover, FGFR4 inhibitor AP24354 can suppress proliferation, invasion and induce apoptosis of CCA cells. In conclusion, FGFR4 expression can be identified as a significant independent prognostic biomarker of IHCC and PHCC. FGFR4 played a pivotal role in proliferation, invasion and EMT of CCA. FGFR4 inhibitor can suppress proliferation, invasion and induce apoptosis of CCA, indicating that FGFR4 may act as a potential therapeutic target.

  8. Clonorchis sinensis Infestation Promotes Three-Dimensional Aggregation and Invasion of Cholangiocarcinoma Cells

    PubMed Central

    Won, Jihee; Ju, Jung-Won; Kim, Sun Min; Shin, Yoojin; Chung, Seok; Pak, Jhang Ho

    2014-01-01

    Numerous experimental and epidemiological studies have demonstrated a correlation between Clonorchis sinensis (C. sinensis) infestation and cholangiocarcinoma (CCA). However, the role of C. sinensis in the increased invasiveness and proliferation involved in the malignancy of CCA has not been addressed yet. Here, we investigated the possibility that C. sinensis infestation promotes expression of focal and cell-cell adhesion proteins in CCA cells and secretion of matrix metalloproteinases (MMPs). Adhesion proteins help maintain cell aggregates, and MMPs promote the three-dimensional invasion of cells into the neighboring extracellular matrix (ECM). Using a novel microfluidic assay, we quantitatively addressed the role of excretory-secretory products (ESPs) gradients from C. sinensis in promoting the invasion of cells into the neighboring ECM. PMID:25340585

  9. Fisetin Reduces Cell Viability Through Up-Regulation of Phosphorylation of ERK1/2 in Cholangiocarcinoma Cells.

    PubMed

    Kim, Nayoung; Lee, Sang Hyub; Son, Jun Hyuk; Lee, Jae Min; Kang, Min-Jung; Kim, Bo Hye; Lee, Jung-Su; Ryu, Ji Kon; Kim, Yong-Tae

    2016-11-01

    Cholangiocarcinoma (CCA) is a malignancy with poor prognosis and limited therapeutic options. Effective prevention and treatment of CCA require developing novel anticancer agents and improved therapeutic regimens. As natural products are concidered a rich source of potential anticancer agents, we investigated the anticancer effect of fisetin in combination with gemcitabine. Cytotoxic effect of fisetin and gemcitabine on a human CCA cell line SNU-308 was assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and apoptosis assay using propidium iodine and annexin V. Molecular mechanisms of fisetin action in CCA were investigated by western blotting. Fisetin was found to inhibit survival of CCA cells, through strongly phosphorylating ERK. It also induced cellular apoptosis additively in combination with gemcitabine. Expression of cellular proliferative markers, such as phospho-p65 and myelocytomatosis (MYC), were reduced by fisetin. These results suggest fisetin in combination with gemcitabine as a candidate for use in improved anticancer regimens. Copyright© 2016 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

  10. Long Noncoding RNA AFAP1-AS1 Promoted Tumor Growth and Invasion in Cholangiocarcinoma.

    PubMed

    Lu, Xu; Zhou, Chuang; Li, Renfeng; Deng, Yilei; Zhao, Longshuan; Zhai, Wenlong

    2017-01-01

    Long non-coding RNAs (lncRNAs) have been shown to play important roles in a wide range of pathophysiological processes, including cancer progression. Our previous study has shown that AFAP1-AS1 was upregulated and acted as an oncogene in hepatocellular carcinoma. However, the expression and biological functions of lncRNA AFAP1-AS1 in intrahepatic cholangiocarcinoma (CCA) remains largely unknown. The expression level of AFAP1-AS1 was measured in 56 pairs of human cholangiocarcinoma tumor tissues and corresponding adjacent normal bile duct tissues. The correlation between AFAP1-AS1 and the clinicopathological features were evaluated by chi-square test. The effects of AFAP1-AS1 on CCA cells were determined by CCK-8 assay, clone formation assay, flow cytometry and transwell assay. Finally, to determine the effect of AFAP1-AS1 on tumor growth in vivo, AFAP1-AS1 knockdowned CCLP-1 cells were subcutaneously into nude mice to evaluate tumor growth. In this study, we found that lncRNA AFAP1-AS1 was increased in CCA tissues and patients with high AFAP1-AS1 expression had a shorter overall survival. SiRNA-mediated AFAP1-AS1 knockdown significantly decreased cell proliferation of the CCA cells, with downregulation of C-myc and Cycling D1 in vitro. Furthermore, AFAP1-AS1 silencing inhibited cell migration partly due to decrease the expression of MMP-2 and MMP-9. In addition, CCLP-1 cells with AFAP1-AS1 knockdown were injected into nude mice to investigate the effect of AFAP1-AS1 on the tumorigenesis in vivo. Taken together, our findings suggested that AFAP1-AS1 might promote the CCA progression and provided a novel potential therapeutic target for CCA. © 2017 The Author(s). Published by S. Karger AG, Basel.

  11. YAP promotes proliferation, chemoresistance, and angiogenesis in human cholangiocarcinoma through TEAD transcription factors.

    PubMed

    Marti, Patricia; Stein, Claudia; Blumer, Tanja; Abraham, Yann; Dill, Michael T; Pikiolek, Monika; Orsini, Vanessa; Jurisic, Giorgia; Megel, Philippe; Makowska, Zuzanna; Agarinis, Claudia; Tornillo, Luigi; Bouwmeester, Tewis; Ruffner, Heinz; Bauer, Andreas; Parker, Christian N; Schmelzle, Tobias; Terracciano, Luigi M; Heim, Markus H; Tchorz, Jan S

    2015-11-01

    The Yes-associated protein (YAP)/Hippo pathway has been implicated in tissue development, regeneration, and tumorigenesis. However, its role in cholangiocarcinoma (CC) is not established. We show that YAP activation is a common feature in CC patient biopsies and human CC cell lines. Using microarray expression profiling of CC cells with overexpressed or down-regulated YAP, we show that YAP regulates genes involved in proliferation, apoptosis, and angiogenesis. YAP activity promotes CC growth in vitro and in vivo by functionally interacting with TEAD transcription factors (TEADs). YAP activity together with TEADs prevents apoptosis induced by cytotoxic drugs, whereas YAP knockdown sensitizes CC cells to drug-induced apoptosis. We further show that the proangiogenic microfibrillar-associated protein 5 (MFAP5) is a direct transcriptional target of YAP/TEAD in CC cells and that secreted MFAP5 promotes tube formation of human microvascular endothelial cells. High YAP activity in human CC xenografts and clinical samples correlates with increased MFAP5 expression and CD31(+) vasculature. These findings establish YAP as a key regulator of proliferation and antiapoptotic mechanisms in CC and provide first evidence that YAP promotes angiogenesis by regulating the expression of secreted proangiogenic proteins. © 2015 by the American Association for the Study of Liver Diseases.

  12. Taurolithocholic acid promotes intrahepatic cholangiocarcinoma cell growth via muscarinic acetylcholine receptor and EGFR/ERK1/2 signaling pathway

    PubMed Central

    AMONYINGCHAROEN, SUMET; SURIYO, TAWIT; THIANTANAWAT, APINYA; WATCHARASIT, PIYAJIT; SATAYAVIVAD, JUTAMAAD

    2015-01-01

    Cholangiocarcinoma (CCA) is a malignant cancer of the biliary tract and its occurrence is associated with chronic cholestasis which causes an elevation of bile acids in the liver and bile duct. The present study aimed to investigate the role and mechanistic effect of bile acids on the CCA cell growth. Intrahepatic CCA cell lines, RMCCA-1 and HuCCA-1, were treated with bile acids and their metabolites to determine the growth promoting effect. Cell viability, cell cycle analysis, EdU incorporation assays were conducted. Intracellular signaling proteins were detected by western immunoblotting. Among eleven forms of bile acids and their metabolites, only taurolithocholic acid (TLCA) concentration dependently (1–40 μM) increased the cell viability of RMCCA-1, but not HuCCA-1 cells. The cell cycle analysis showed induction of cells in the S phase and the EdU incorporation assay revealed induction of DNA synthesis in the TLCA-treated RMCCA-1 cells. Moreover, TLCA increased the phosphorylation of EGFR, ERK 1/2 and also increased the expression of cyclin D1 in RMCCA-1 cells. Furthermore, TLCA-induced RMCCA-1 cell growth could be inhibited by atropine, a non-selective muscarinic acetylcholine receptor (mAChR) antagonist, AG 1478, a specific EGFR inhibitor, or U 0126, a specific MEK 1/2 inhibitor. These results suggest that TLCA induces CCA cell growth via mAChR and EGFR/EKR1/2 signaling pathway. Moreover, the functional presence of cholinergic system plays a certain role in TLCA-induced CCA cell growth. PMID:25815516

  13. Protein tyrosine phosphatase PTP4A1 promotes proliferation and epithelial-mesenchymal transition in intrahepatic cholangiocarcinoma via the PI3K/AKT pathway

    PubMed Central

    Ma, Li-Jie; Wang, Zhi-Chao; Liu, Xin-Yang; Duan, Meng; Yang, Liu-Xiao; Shi, Jie-Yi; Zhou, Jian; Fan, Jia; Gao, Qiang; Wang, Xiao-Ying

    2016-01-01

    The protein tyrosine phosphatase PTP4A1 is a key molecule that activates tyrosine phosphorylation, which is important for cancer progression and metastasis. However, the clinical implications and biological function of PTP4A1 in intrahepatic cholangiocarcinoma (ICC) remains unknown. Here, we showed that PTP4A1 was frequently overexpressed in ICC versus adjacent non-tumor tissues. This overexpression significantly correlated with aggressive tumor characteristics like the presence of lymph node metastasis and advanced tumor stages. Survival analysis further indicated that high PTP4A1 expression was significantly and independently associated with worse survival and increased recurrence in ICC patients. Moreover, through forced overexpression and knock-down of PTPT4A1, we demonstrated that PTP4A1 could significantly promote ICC cells proliferation, colony formation, migration, and invasion in vitro, and markedly enhance tumor progression in vivo. Mechanistically, PTP4A1 was involved in PI3K/AKT signaling and its downstream molecules, such as phosphorylation level of GSK3β and up-regulation of CyclinD1, in ICC cells to promote proliferation. Importantly, PTP4A1 induced ICC cells invasion was through activating PI3K/AKT signaling controlled epithelial-mesenchymal transition (EMT) process by up-regulating Zeb1 and Snail. Thus, PTP4A1 may serve as a potential oncogene that was a valuable prognostic biomarker and therapeutic target for ICC. PMID:27655691

  14. Aberrant expression of laminin γ2 correlates with poor prognosis and promotes invasion in extrahepatic cholangiocarcinoma.

    PubMed

    Liu, Wei; Tian, Feng; Jiang, Peng; Zhao, Xin; Guo, Fei; Li, Xiaowu; Wang, Shuguang

    2014-01-01

    To investigate the potential role of laminin γ2 and its correlation with prognosis in patients with extrahepatic cholangiocarcinoma (CCA). Laminin γ2 expression was evaluated by immunohistochemistry in 72 extrahepatic CCA patients after surgical resection. Knockdown of laminin γ2 was achieved via small interfering RNA transfection in the extrahepatic CCA cell line QBC939. Thirty-six of 72 extrahepatic CCAs (50%) stained positive for laminin γ2 in two types of patterns: stromal staining (28/72, 39%) and cytoplasmic staining (24/72, 33%). All 16 paracancerous tissue samples showed negative staining. Both stromal and cytoplasmic laminin γ2 expressions correlated with lymph node metastasis. Kaplan-Meier analysis showed that aberrant expression of laminin γ2 correlated with poor overall survival and early recurrence. Cox regression analysis further demonstrated that laminin γ2 expression was a significant independent predictor of poor overall survival and early recurrence. Immunofluorescence staining revealed cytoplasmic expression of laminin γ2 in QBC939 cells. Knockdown of laminin γ2 significantly reduced QBC939 cell invasion and migration. Aberrant expression of laminin γ2 correlates with poor prognosis and promotes invasion in extrahepatic CCA. Crown Copyright © 2014. Published by Elsevier Inc. All rights reserved.

  15. Conjugated bile acids promote cholangiocarcinoma cell invasive growth through activation of sphingosine 1-phosphate receptor 2

    PubMed Central

    Liu, Runping; Zhao, Renping; Zhou, Xiqiao; Liang, Xiuyin; Campbell, Deanna JW; Zhang, Xiaoxuan; Zhang, Luyong; Shi, Ruihua; Wang, Guangji; Pandak, William M; Sirica, Alphonse E; Hylemon, Phillip B; Zhou, Huiping

    2014-01-01

    Cholangiocarcinoma (CCA) is an often fatal primary malignancy of the intra- and extrahepatic biliary tract that is commonly associated with chronic cholestasis and significantly elevated levels of primary and conjugated bile acids (CBAs), which are correlated with bile duct obstruction (BDO). BDO has also recently been shown to promote CCA progression. However, whereas there is increasing evidence linking chronic cholestasis and abnormal bile acid profiles to CCA development and progression, the specific mechanisms by which bile acids may be acting to promote cholangiocarcinogenesis and invasive biliary tumor growth have not been fully established. Recent studies have shown that CBAs, but not free bile acids, stimulate CCA cell growth, and that an imbalance in the ratio of free to CBAs may play an important role in the tumorigenesis of CCA. Also, CBAs are able to activate extracellular signal-regulated kinase (ERK)1/2- and phosphatidylinositol-3-kinase/protein kinase B (AKT)-signaling pathways through sphingosine 1-phosphate receptor 2 (S1PR2) in rodent hepatocytes. In the current study, we demonstrate S1PR2 to be highly expressed in rat and human CCA cells, as well as in human CCA tissues. We further show that CBAs activate the ERK1/2- and AKT-signaling pathways and significantly stimulate CCA cell growth and invasion in vitro. Taurocholate (TCA)-mediated CCA cell proliferation, migration, and invasion were significantly inhibited by JTE-013, a chemical antagonist of S1PR2, or by lentiviral short hairpin RNA silencing of S1PR2. In a novel organotypic rat CCA coculture model, TCA was further found to significantly increase the growth of CCA cell spheroidal/“duct-like” structures, which was blocked by treatment with JTE-013. Conclusion: Our collective data support the hypothesis that CBAs promote CCA cell-invasive growth through S1PR2. PMID:24700501

  16. Sustained IL-6/STAT-3 Signaling in Cholangiocarcinoma Cells due to SOCS-3 Epigenetic Silencing

    PubMed Central

    Isomoto, Hajime; Mott, Justin L.; Kobayashi, Shogo; Werneburg, Nathan W.; Bronk, Steve F.; Haan, Serge; Gores, Gregory J.

    2008-01-01

    Background and aims IL-6 mediated STAT-3 phosphorylation (activation) is aberrantly sustained in cholangiocarcinoma cells resulting in enhanced Mcl-1 expression and resistance to apoptosis. Because SOCS-3 controls the IL-6/STAT-3 signaling pathway by a classic feedback loop, the aims of this study were to examine SOCS-3 regulation in human cholangiocarcinoma. Methods SOCS-3 expression was assessed in human cholangiocarcinoma tissue and the Mz-ChA-1 and CCLP1 human cholangiocarcinoma cell lines. Results An inverse correlation was observed between phospho-STAT-3 and SOCS-3 protein expression in cholangiocarcinoma. In those cancers failing to express SOCS-3, extensive methylation of the SOCS-3 promoter was demonstrated in tumor but not in paired non-tumor tissue. Likewise, methylation of the socs-3 promoter was also identified in two cholangiocarcinoma cell lines. Treatment with a demethylating agent, 5-aza-2′-deoxycytidine (DAC), restored IL-6 induction of SOCS-3, terminated the phospho-STAT-3 response, and reduced cellular levels of Mcl-1. Enforced expression of SOCS-3 also reduced IL-6 induction of phospho-STAT-3 and Mcl-1. Either DAC treatment or enforced SOCS-3 expression sensitized the cells to TRAIL-mediated apoptosis. Conclusion SOCS-3 epigenetic silencing is responsible for sustained IL-6/STAT-3 signaling and enhanced Mcl-1 expression in cholangiocarcinoma. PMID:17241887

  17. c‑Myc promotes cholangiocarcinoma cells to overcome contact inhibition via the mTOR pathway.

    PubMed

    Luo, Guosong; Li, Bin; Duan, Chunyan; Cheng, Ying; Xiao, Bin; Yao, Fuli; Wei, Mei; Tao, Qinghua; Feng, Chunhong; Xia, Xianming; Zhou, Hong; Zhao, Xiaofang; Dai, Rongyang

    2017-10-01

    The loss of contact inhibition is a hallmark of a wide range of human cancer cells. Yet, the precise mechanism behind this process is not fully understood. c‑Myc plays a pivotal role in carcinogenesis, but its involvement in regulating contact inhibition has not been explored to date. Here, we report that c‑Myc plays an important role in abrogating contact inhibition in human cholangiocarcinoma (CCA) cells. Our data show that the protein level of c‑Myc obviously decreased in contact-inhibited normal biliary epithelial cells. However, CCA cells sustain high protein levels of c‑Myc and keep strong proliferation ability in confluent conditions. Importantly, the suppression of c‑Myc by inhibitor or siRNA induced G0/G1 phase cell cycle arrest in confluent CCA cells. We demonstrate that the inhibition of c‑Myc suppressed the activity of mammalian target of rapamycin (mTOR) in confluent CCA cells, and mTOR inhibition induced G0/G1 phase cell cycle arrest in confluent CCA cells. In confluent CCA cells, the activity of Merlin is downregulated, and Yes-associated protein (YAP) sustains high levels of activity. Furthermore, YAP inhibition not only induced G0/G1 phase cell cycle arrest, but also decreased c‑Myc expression in confluent CCA cells. These results indicate that Merlin/YAP/c‑Myc/mTOR signaling axis promotes human CCA cell proliferation by overriding contact inhibition. We propose that overriding c‑Myc‑mediated contact inhibition is implicated in the development of CCA.

  18. Activated macrophages promote Wnt/β-catenin signaling in cholangiocarcinoma cells

    PubMed Central

    Loilome, Watcharin; Bungkanjana, Pornpan; Techasen, Anchalee; Namwat, Nisana; Yongvanit, Puangrat; Puapairoj, Anucha; Khuntikeo, Narong; Riggins, Gregory J.

    2016-01-01

    The Wnt/β-catenin signaling pathway is pathologically activated in cholangiocarcinoma (CCA). Here, we determined the expression profile as well as biological role of activated Wnt/β-catenin signaling in CCA. The quantitative reverse transcription polymerase chain reaction demonstrated that Wnt3a, Wnt5a, and Wnt7b mRNA were significantly higher in CCA tissues than adjacent non-tumor tissues and normal liver tissues. Immunohistochemical staining revealed that Wnt3a, Wnt5a, and Wnt7b were positive in 92.1, 76.3, and 100 % of 38 CCA tissues studied. It was noted that Wnt3 had a low expression in tumor cells, whereas a high expression was mainly found in inflammatory cells. Interestingly, a high expression level of Wnt5a was significantly correlated to poor survival of CCA patients (P=0.009). Membrane localization of β-catenin was reduced in the tumors compared to normal bile duct epithelia, and we also found that 73.7 % of CCA cases showed the cytoplasmic localization. Inflammation is known to be a risk factor for CCA development, and we tested whether this might induce Wnt/β-catenin signaling. We found that lipopolysaccharides (LPS) elevated the expression of Wnt3 both mRNA and protein levels in the macrophage cell line. Additionally, the conditioned media taken from LPS-induced activated macrophage culture promoted β-catenin accumulation in CCA cells. Furthermore, transient suppression of β-catenin by siRNA significantly induced growth inhibition of CCA cells, concurrently with decreasing cyclin D1 protein level. In conclusion, the present study reports the abundant expression of Wnt protein family and β-catenin in CCA as well as the effect of inflammatory condition on Wnt/β-catenin activation in CCA cells. Importantly, abrogation of β-catenin expression caused significant CCA cell growth inhibition. Thus, the Wnt/β-catenin signaling pathway may contribute to CCA cell proliferation and hence may serve as a prognostic marker for CCA progression and provide a

  19. Clonorchis sinensis excretory-secretory products promote the migration and invasion of cholangiocarcinoma cells by activating the integrin β4-FAK/Src signaling pathway.

    PubMed

    Pak, Jhang Ho; Bashir, Qudsia; Kim, In Ki; Hong, Sung-Jong; Maeng, Sejung; Bahk, Young Yil; Kim, Tong-Soo

    2017-03-08

    Cholangiocarcinoma (CCA) is a slow-growing but highly metastatic cancer. Its metastatic potential largely explains its high mortality rate. A recognized risk factor for CCA development is infection with the liver flukes Opisthorchis viverrini and Clonorchis sinensis. We previously reported that the excretory-secretory products (ESPs) of C. sinensis promoted the three-dimensional aggregation and invasion of CCA cells. In the present study, a quantitative real-time PCR array of extracellular matrix (ECM) and adhesion molecules was used to examine the regulatory mechanism of ESP-mediated CCA cell migration and invasion. In particular, the expression levels of integrin α isoforms and β4 were upregulated in response to ESPs. Increased expression of integrin β4 was probably correlated with activation of focal adhesion kinase (FAK) and the steroid receptor coactivator (Src) family kinase and the subsequent activation of two downstream focal adhesion molecules, paxillin and vinculin. Moreover, inhibition of FAK/Src activation reduced paxillin and vinculin phosphorylation and attenuated ESP-induced CCA cell migration and invasion. These findings suggest that the integrin β4-FAK/Src signaling axis may play a crucial role in clonorchiasis-associated CCA metastasis during tumor progression.

  20. Molecular Pathogenesis of Cholangiocarcinoma

    PubMed Central

    Rizvi, Sumera; Gores, Gregory J.

    2014-01-01

    It has become increasingly apparent of late that inflammation plays an integral role in a spectrum of malignancies including cholangiocarcinoma. Primary sclerosing cholangitis with chronic inflammation is the most common risk factor for cholangiocarcinoma in the Western World. Recent work has highlighted that inflammatory pathways are essential in carcinogenesis and tissue invasion and migration. Inflammation advances carcinogenesis by induction of DNA damage, evasion of apoptosis, promotion of cell proliferation, and neoangiogenesis. Cholangiocarcinoma is characterized by the presence of a desmoplastic stroma consisting of cancer associated fibroblasts, tumor associated macrophages, and tumor infiltrating lymphocytes. This rich inflammatory milieu is vital to the cancer ecosystem, and targeting its components represents an attractive therapeutic option. PMID:25034289

  1. Myofibroblast-derived PDGF-BB Promotes Hedgehog Survival Signaling in Cholangiocarcinoma Cells

    PubMed Central

    Fingas, C D; Bronk, S F; Werneburg, N W; Mott, J L; Guicciardi, M E; Cazanave, S C; Mertens, J C; Sirica, A E; Gores, G J

    2011-01-01

    Cholangiocarcinoma (CCA) cells paradoxically express the death ligand TRAIL, and, therefore, are dependent upon potent survival signals to circumvent TRAIL cytotoxicity. CCAs are also highly desmoplastic cancers with a tumor microenvironment rich in myofibroblasts (MFBs). Herein, we examine a role for MFB-derived CCA survival signals. We employed human KMCH-1, KMBC, HuCCT-1, TFK-1, and Mz-ChA-1 CCA cells as well as human primary hepatic stellate and myofibroblastic LX-2 cells for these studies. In vivo experiments were conducted using a syngeneic rat orthotopic CCA model. Co-culturing CCA cells with myofibroblastic human primary HSCs or LX-2 cells significantly decreased TRAIL-induced apoptosis in CCA cells, a cytoprotective effect abrogated by neutralizing PDGF-BB-antiserum. Cytoprotection by PDGF-BB was dependent upon Hedgehog (Hh) signaling as it was abolished by the smoothened (the transducer of Hh signaling) inhibitor cyclopamine. PDGF-BB induced PKA-dependent trafficking of smoothened to the plasma membrane resulting in GLI2 nuclear translocation and activation of a consensus GLI reporter gene-based luciferase assay. A genome-wide mRNA expression analysis identified 67 target genes to be commonly up- (50 genes) or downregulated (17 genes) by both SHH and PDGF-BB in a cyclopamine-dependent manner in CCA cells. Finally, in a rodent CCA in vivo-model, cyclopamine administration increased apoptosis in CCA cells resulting in tumor suppression. Conclusions Myofibroblast-derived PDGF-BB protects CCA cells from TRAIL cytotoxicity by a Hh signaling-dependent process. These results have therapeutical implications for the treatment of human cholangiocarcinoma. PMID:22038837

  2. MenaINV dysregulates cortactin phosphorylation to promote invadopodium maturation

    PubMed Central

    Weidmann, Maxwell D.; Surve, Chinmay R.; Eddy, Robert J.; Chen, Xiaoming; Gertler, Frank B.; Sharma, Ved P.; Condeelis, John S.

    2016-01-01

    Invadopodia, actin-based protrusions of invasive carcinoma cells that focally activate extracellular matrix-degrading proteases, are essential for the migration and intravasation of tumor cells during dissemination from the primary tumor. We have previously shown that cortactin phosphorylation at tyrosine residues, in particular tyrosine 421, promotes actin polymerization at newly-forming invadopodia, promoting their maturation to matrix-degrading structures. However, the mechanism by which cells regulate the cortactin tyrosine phosphorylation-dephosphorylation cycle at invadopodia is unknown. Mena, an actin barbed-end capping protein antagonist, is expressed as various splice-isoforms. The MenaINV isoform is upregulated in migratory and invasive sub-populations of breast carcinoma cells, and is involved in tumor cell intravasation. Here we show that forced MenaINV expression increases invadopodium maturation to a far greater extent than equivalent expression of other Mena isoforms. MenaINV is recruited to invadopodium precursors just after their initial assembly at the plasma membrane, and promotes the phosphorylation of cortactin tyrosine 421 at invadopodia. In addition, we show that cortactin phosphorylation at tyrosine 421 is suppressed by the phosphatase PTP1B, and that PTP1B localization to the invadopodium is reduced by MenaINV expression. We conclude that MenaINV promotes invadopodium maturation by inhibiting normal dephosphorylation of cortactin at tyrosine 421 by the phosphatase PTP1B. PMID:27824079

  3. Mechanistic insights of O-GlcNAcylation that promote progression of cholangiocarcinoma cells via nuclear translocation of NF-κB

    PubMed Central

    Phoomak, Chatchai; Vaeteewoottacharn, Kulthida; Sawanyawisuth, Kanlayanee; Seubwai, Wunchana; Wongkham, Chaisiri; Silsirivanit, Atit; Wongkham, Sopit

    2016-01-01

    O-GlcNAcylation, an O-linked protein glycosylation with a single molecule of N-acetylglucosamine (GlcNAc), is reversibly controlled by O-GlcNAc transferase (OGT) and N-acetyl D-glucosaminidase (OGA). Aberrant O-GlcNAcylation contributes an important role in initiation and progression of many human cancers. Elevation of O-GlcNAcylation in tumor tissues and poor prognosis of cholangiocarcinoma (CCA) patients have been reported. In this study, the role of O-GlcNAcylation in promoting tumor progression was further investigated in CCA cell lines. Suppression of O-GlcNAcylation using small interfering RNAs of OGT (siOGT) significantly reduced cell migration and invasion of CCA cells whereas siOGA treated cells exhibited opposite effects. Manipulating levels of O-GlcNAcylation did affect the nuclear translocation of NF-κB and Akt-phosphorylation together with expression of matrix-metalloproteinases (MMPs). O-GlcNAcylation and nuclear translocation of NF-κB, the upstream signaling cascade of MMP activation were shown to be important for MMP activation. Immunoprecipitation revealed the elevation of O-GlcNAc-modified NF-κB with increased cellular O-GlcNAcylation. Involvement of O-GlcNAcylation in MMP-mediated migration and invasion of CCA cells was shown to be via O-GlcNAcylation and nuclear translocation of NF-κB. This information indicates the significance of O-GlcNAcylation in controlling the metastatic ability of CCA cells, hence, O-GlcNAcylation and its products may be new targets for treatment of metastatic CCA. PMID:27290989

  4. Bile Duct Cancer (Cholangiocarcinoma)

    MedlinePlus

    ... Types of Cancer > Bile Duct Cancer (Cholangiocarcinoma) Bile Duct Cancer (Cholangiocarcinoma) This is Cancer.Net’s Guide to Bile Duct Cancer (Cholangiocarcinoma). Use the menu below to choose ...

  5. PKCζ PHOSPHORYLATES OCCLUDIN AND PROMOTES ASSEMBLY OF EPITHELIAL TIGHT JUNCTIONS

    PubMed Central

    Jain, Suneet; Suzuki, Takuya; Seth, Ankur; Samak, Geetha; Rao, RadhaKrishna

    2012-01-01

    SYNOPSIS Evidence indicates that protein kinases play an important role in the regulation of epithelial tight junctions. In the present study, we investigated the role of PKCζ in tight junction regulation in Caco-2 and MDCK cell monolayers. Inhibition of PKCζ by a specific PKCζ-pseudosubstrate peptide results in redistribution of occludin and ZO-1 from the intercellular junctions and disruption of barrier function without affecting cell viability. Reduced expression of PKCζ by antisense oligonucleotide or shRNA also results in compromised tight junction integrity. Inhibition or knock down of PKCζ delays calcium-induced assembly of tight junctions. Tight junction disruption by PKCζ-pseudosubstrate is associated with the dephosphorylation of occludin and ZO-1 on Ser and Thr residues. PKCζ directly binds to the C-terminal domain of occludin and phosphorylates it on Thr residues. T403, T404, T424 and T438 in occludin C-terminal domain are the predominant sites of PKCζ-dependent phosphorylation. T424A or T438A mutation in full length occludin delays its assembly into the tight junctions. Inhibition of PKCζ also induces redistribution of occludin and ZO-1 from the tight junctions and dissociates these proteins from the detergent-insoluble fractions in mouse ileum. This study demonstrates that PKCζ phosphorylates occludin on specific Thr residues and promotes assembly of epithelial tight junctions. PMID:21545357

  6. Deregulated Methionine Adenosyltransferase α1, c-Myc and Maf Proteins Interplay Promotes Cholangiocarcinoma Growth in Mice and Humans

    PubMed Central

    Yang, Heping; Liu, Ting; Wang, Jiaohong; Li, Tony W.H.; Fan, Wei; Peng, Hui; Krishnan, Anuradha; Gores, Gregory J.; Mato, Jose M.; Lu, Shelly C.

    2016-01-01

    We reported c-Myc induction drives cholestatic liver injury and cholangiocarcinoma (CCA) in mice. We also showed induction of Maf proteins (MafG and c-Maf) contributed to cholestatic liver injury, whereas S-adenosylmethionine (SAMe) administration was protective. Here we determined whether there is interplay between c-Myc, Maf proteins and methionine adenosyltransferase α1 (MATα1), which is responsible for SAMe biosynthesis in liver. We used bile duct ligation (BDL) and lithocholic acid (LCA) treatment in mice as chronic cholestasis models, a murine CCA model, human CCA cell lines KMCH and Huh-28, human liver cancer HepG2, and human CCA specimens to study gene and protein expression, protein-protein interactions, molecular mechanisms and functional outcomes. We found c-Myc, MATα1 (encoded by MAT1A), MafG and c-Maf interact with each other directly. MAT1A expression fell in hepatocytes and bile duct epithelial cells during chronic cholestasis and in murine and human CCA. The opposite occurred with c-Myc, MafG and c-Maf expression. MATα1 interacts mainly with Mnt in normal liver but this switches to c-Maf, MafG and c-Myc in cholestatic livers and CCA. Promoter regions of these genes have E-boxes that are bound by MATα1 and Mnt in normal liver and benign bile duct epithelial cells that switched to c-Myc, c-Maf and MafG in cholestasis and CCA cells. E-box positively regulates c-Myc, MafG and c-Maf, but it negatively regulates MAT1A. MATα1 represses whereas c-Myc, MafG and c-Maf enhance E-box-driven promoter activity. Knocking down MAT1A or overexpressing MafG or c-Maf enhanced CCA growth and invasion in vivo. Conclusion We have uncovered a novel interplay between MATα1, c-Myc and Maf proteins and their deregulation during chronic cholestasis may facilitate CCA oncogenesis. PMID:26969892

  7. Src promotes GTPase activity of Ras via tyrosine 32 phosphorylation

    PubMed Central

    Bunda, Severa; Heir, Pardeep; Srikumar, Tharan; Cook, Jonathan D.; Burrell, Kelly; Kano, Yoshihito; Lee, Jeffrey E.; Zadeh, Gelareh; Raught, Brian; Ohh, Michael

    2014-01-01

    Mutations in Ras GTPase and various other components of the Ras signaling pathways are among the most common genetic alterations in human cancers and also have been identified in several familial developmental syndromes. Over the past few decades it has become clear that the activity or the oncogenic potential of Ras is dependent on the nonreceptor tyrosine kinase Src to promote the Ras/Raf/MAPK pathway essential for proliferation, differentiation, and survival of eukaryotic cells. However, no direct relationship between Ras and Src has been established. We show here that Src binds to and phosphorylates GTP-, but not GDP-, loaded Ras on a conserved Y32 residue within the switch I region in vitro and that in vivo, Ras-Y32 phosphorylation markedly reduces the binding to effector Raf and concomitantly increases binding to GTPase-activating proteins and the rate of GTP hydrolysis. These results suggest that, in the context of predetermined crystallographic structures, Ras-Y32 serves as an Src-dependent keystone regulatory residue that modulates Ras GTPase activity and ensures unidirectionality to the Ras GTPase cycle. PMID:25157176

  8. HDAC10 promotes lung cancer proliferation via AKT phosphorylation

    PubMed Central

    Wang, Zhantong; Wang, Hsin-tzu; Duan, Baoyu; Ye, Dan; Wang, Chenxin; Jing, Ruiqi; Leng, Ye; Xi, Jiajie; Chen, Wen; Wang, Guiying; Jia, Wenwen; Zhu, Songcheng; Kang, Jiuhong

    2016-01-01

    Histone deacetylase 10 (HDAC10) is a member of the class II HDACs, and its role in cancer is emerging. In this study, we found that HDAC10 is highly expressed in lung cancer tissues. It resides mainly in the cytoplasm of lung cancer cells but resides in the nucleus of adjacent normal cells. Further examinations revealed that HDAC10 resides in the cytoplasm in multiple lung cancer cell lines, including the A549, H358 and H460 cell lines, but mainly resides in the nucleus of normal lung epithelial 16HBE cells. A leucine-rich motif, R505L506L507C508V509A510L511, was identified as its nuclear localization signal (NLS), and a mutant (Mut-505-511) featuring mutations to A at each of its original R and L positions was found to be nuclear-localization defective. Functional analysis revealed that HDAC10 promoted lung cancer cell growth and that its knockdown induced cell cycle arrest and apoptosis. Mechanistic studies showed that HDAC10 knockdown significantly decreased the phosphorylation of AKT at Ser473 and that AKT expression significantly rescued the cell cycle arrest and apoptosis elicited by HDAC10 knockdown. A co-immunoprecipitation assay suggested that HDAC10 interacts with AKT and that inhibition of HDAC10 activity decreases its interaction with and phosphorylation of AKT. Finally, we confirmed that HDAC10 promoted lung cancer proliferation in a mouse model. Our study demonstrated that HDAC10 localizes and functions in the cytoplasm of lung cancer cells, thereby underscoring its potential role in the diagnosis and treatment of lung cancer. PMID:27449083

  9. Sumoylation in p27kip1 via RanBP2 promotes cancer cell growth in cholangiocarcinoma cell line QBC939.

    PubMed

    Yang, Jun; Liu, Yan; Wang, Bing; Lan, Hongzhen; Liu, Ying; Chen, Fei; Zhang, Ju; Luo, Jian

    2017-09-07

    Cholangiocarcinoma is one of the deadly disease with poor 5-year survival and poor response to conventional therapies. Previously, we found that p27kip1 nuclear-cytoplasmic translocation confers proliferation potential to cholangiocarcinoma cell line QBC939 and this process is mediated by crm-1. However, no other post-transcriptional regulation was found in this process including sumoylation in cholangiocarcinoma. In this study, we explored the role of sumoylation in the nuclear-cytoplasmic translocation of p27kip1 and its involvement of QBC939 cells' proliferation. First, we identified K73 as the sumoylation site in p27kip1. By utilizing plasmid flag-p27kip1, HA-RanBP2, GST-RanBP2 and His-p27kip1 and immunoprecipitation assay, we validated that p27kip1 can serve as the sumoylation target of RanBP2 in QBC939. Furthermore, we confirmed crm-1's role in promoting nuclear-cytoplasmic translocation of p27kip1 and found that RanBP2's function relies on crm-1. However, K73R mutated p27kip1 can't be identified by crm-1 or RanBP2 in p27kip1 translocation process, suggesting sumoylation of p27kip1 via K73 site is necessary in this process by RanBP2 and crm-1. Phenotypically, the overexpression of either RanBP2 or crm-1 can partially rescue the anti-proliferative effect brought by p27kip1 overexpression in both the MTS and EdU assay. For the first time, we identified and validated the K73 sumoylation site in p27kip1, which is critical to RanBP2 and crm-1 in p27kip1 nuclear-cytoplasmic translocation process. Taken together, targeted inhibition of sumoylation of p27kip1 may serve as a potentially potent therapeutic target in the eradication of cholangiocarcinoma development and relapses.

  10. Intrahepatic Cholangiocarcinoma Progression: Prognostic Factors and Basic Mechanisms

    PubMed Central

    Sirica, Alphonse E.; Dumur, Catherine I.; Campbell, Deanna J. W.; Almenara, Jorge A.; Ogunwobi, Olorunseun O.; Dewitt, Jennifer L.

    2013-01-01

    In this review, we will examine various molecular biomarkers for their potential to serve as independent prognostic factors for predicting survival outcome in postoperative patients with progressive intrahepatic cholangiocarcinoma. Specific rodent models of intrahepatic cholangiocarcinoma that mimic relevant cellular, molecular, and clinical features of the human disease are also described, not only in terms of their usefulness in identifying molecular pathways and mechanisms linked to cholangiocarcinoma development and progression, but also for their potential value as preclinical platforms for suggesting and testing novel molecular strategies for cholangiocarcinoma therapy. Last, recent studies aimed at addressing the role of desmoplastic stroma in promoting intrahepatic cholangiocarcinoma progression are highlighted in an effort to underline the potential value of targeting tumor stromal components together with that of cholangiocarcinoma cells as a novel therapeutic option for this devastating cancer. PMID:19896103

  11. SKI promotes Smad3 linker phosphorylations associated with the tumor-promoting trait of TGFbeta.

    PubMed

    Lin, Qiushi; Chen, Dahu; Timchenko, Nikolai A; Medrano, Estela E

    2010-05-01

    The transcriptional co-regulator SKI is a potent inhibitor of TGFbeta-growth inhibitory signals. SKI binds to receptor-activated Smads in the nucleus, forming repressor complexes containing HDACs, mSin3, NCoR, and other protein partners. Alternatively, SKI binds to activated Smads in the cytoplasm, preventing their nuclear translocation. SKI is necessary for anchorage-independent growth of melanoma cells in vitro, and most important, for human melanoma xenograft growth in vivo. We recently identified a novel role of SKI in TGFbeta signaling. SKI promotes the switch of Smad3 from repressor of proliferation to activator of oncogenesis by facilitating phosphorylations in the linker domain. High levels of endogenous SKI are required by the tumor promoting trait of TGFbeta to induce expression of the plasminogen-activator inhibitor-1 (PAI-1), sustained expression of C-Myc and for aborting upregulation of p21(Waf-1). Here we discuss how SKI diversifies and amplifies its functions by associating with multiple protein partners and by promoting Smad3 linker phosphorylation(s) in response to TGFbeta signaling in melanoma cells.

  12. Mammalian FMRP S499 Is Phosphorylated by CK2 and Promotes Secondary Phosphorylation of FMRP

    PubMed Central

    O’Keefe, Rachel A.; Blice-Baum, Anna; Gong, Xuan; Karaca, Esra

    2016-01-01

    Abstract The fragile X mental retardation protein (FMRP) is an mRNA-binding regulator of protein translation that associates with 4-6% of brain transcripts and is central to neurodevelopment. Autism risk genes’ transcripts are overrepresented among FMRP-binding mRNAs, and FMRP loss-of-function mutations are responsible for fragile X syndrome, the most common cause of monogenetic autism. It is thought that FMRP-dependent translational repression is governed by the phosphorylation of serine residue 499 (S499). However, recent evidence suggests that S499 phosphorylation is not modulated by metabotropic glutamate receptor class I (mGluR-I) or protein phosphatase 2A (PP2A), two molecules shown to regulate FMRP translational repression. Moreover, the mammalian FMRP S499 kinase remains unknown. We found that casein kinase II (CK2) phosphorylates murine FMRP S499. Further, we show that phosphorylation of FMRP S499 permits phosphorylation of additional, nearby residues. Evidence suggests that these nearby residues are modulated by mGluR-I and PP2A pathways. These data support an alternative phosphodynamic model of FMRP that is harmonious with prior studies and serves as a framework for further investigation. PMID:27957526

  13. An Argonaute phosphorylation cycle promotes microRNA-mediated silencing.

    PubMed

    Golden, Ryan J; Chen, Beibei; Li, Tuo; Braun, Juliane; Manjunath, Hema; Chen, Xiang; Wu, Jiaxi; Schmid, Vanessa; Chang, Tsung-Cheng; Kopp, Florian; Ramirez-Martinez, Andres; Tagliabracci, Vincent S; Chen, Zhijian J; Xie, Yang; Mendell, Joshua T

    2017-02-09

    MicroRNAs (miRNAs) perform critical functions in normal physiology and disease by associating with Argonaute proteins and downregulating partially complementary messenger RNAs (mRNAs). Here we use clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated protein 9 (Cas9) genome-wide loss-of-function screening coupled with a fluorescent reporter of miRNA activity in human cells to identify new regulators of the miRNA pathway. By using iterative rounds of screening, we reveal a novel mechanism whereby target engagement by Argonaute 2 (AGO2) triggers its hierarchical, multi-site phosphorylation by CSNK1A1 on a set of highly conserved residues (S824-S834), followed by rapid dephosphorylation by the ANKRD52-PPP6C phosphatase complex. Although genetic and biochemical studies demonstrate that AGO2 phosphorylation on these residues inhibits target mRNA binding, inactivation of this phosphorylation cycle globally impairs miRNA-mediated silencing. Analysis of the transcriptome-wide binding profile of non-phosphorylatable AGO2 reveals a pronounced expansion of the target repertoire bound at steady-state, effectively reducing the active pool of AGO2 on a per-target basis. These findings support a model in which an AGO2 phosphorylation cycle stimulated by target engagement regulates miRNA:target interactions to maintain the global efficiency of miRNA-mediated silencing.

  14. A sequential multi-target Mps1 phosphorylation cascade promotes spindle checkpoint signaling

    PubMed Central

    Ji, Zhejian; Gao, Haishan; Jia, Luying; Li, Bing; Yu, Hongtao

    2017-01-01

    The master spindle checkpoint kinase Mps1 senses kinetochore-microtubule attachment and promotes checkpoint signaling to ensure accurate chromosome segregation. The kinetochore scaffold Knl1, when phosphorylated by Mps1, recruits checkpoint complexes Bub1–Bub3 and BubR1–Bub3 to unattached kinetochores. Active checkpoint signaling ultimately enhances the assembly of the mitotic checkpoint complex (MCC) consisting of BubR1–Bub3, Mad2, and Cdc20, which inhibits the anaphase-promoting complex or cyclosome bound to Cdc20 (APC/CCdc20) to delay anaphase onset. Using in vitro reconstitution, we show that Mps1 promotes APC/C inhibition by MCC components through phosphorylating Bub1 and Mad1. Phosphorylated Bub1 binds to Mad1–Mad2. Phosphorylated Mad1 directly interacts with Cdc20. Mutations of Mps1 phosphorylation sites in Bub1 or Mad1 abrogate the spindle checkpoint in human cells. Therefore, Mps1 promotes checkpoint activation through sequentially phosphorylating Knl1, Bub1, and Mad1. This sequential multi-target phosphorylation cascade makes the checkpoint highly responsive to Mps1 and to kinetochore-microtubule attachment. DOI: http://dx.doi.org/10.7554/eLife.22513.001 PMID:28072388

  15. Tyr-301 Phosphorylation Inhibits Pyruvate Dehydrogenase by Blocking Substrate Binding and Promotes the Warburg Effect*

    PubMed Central

    Fan, Jun; Kang, Hee-Bum; Shan, Changliang; Elf, Shannon; Lin, Ruiting; Xie, Jianxin; Gu, Ting-Lei; Aguiar, Mike; Lonning, Scott; Chung, Tae-Wook; Arellano, Martha; Khoury, Hanna J.; Shin, Dong M.; Khuri, Fadlo R.; Boggon, Titus J.; Kang, Sumin; Chen, Jing

    2014-01-01

    The mitochondrial pyruvate dehydrogenase complex (PDC) plays a crucial role in regulation of glucose homoeostasis in mammalian cells. PDC flux depends on catalytic activity of the most important enzyme component pyruvate dehydrogenase (PDH). PDH kinase inactivates PDC by phosphorylating PDH at specific serine residues, including Ser-293, whereas dephosphorylation of PDH by PDH phosphatase restores PDC activity. The current understanding suggests that Ser-293 phosphorylation of PDH impedes active site accessibility to its substrate pyruvate. Here, we report that phosphorylation of a tyrosine residue Tyr-301 also inhibits PDH α 1 (PDHA1) by blocking pyruvate binding through a novel mechanism in addition to Ser-293 phosphorylation. In addition, we found that multiple oncogenic tyrosine kinases directly phosphorylate PDHA1 at Tyr-301, and Tyr-301 phosphorylation of PDHA1 is common in EGF-stimulated cells as well as diverse human cancer cells and primary leukemia cells from human patients. Moreover, expression of a phosphorylation-deficient PDHA1 Y301F mutant in cancer cells resulted in increased oxidative phosphorylation, decreased cell proliferation under hypoxia, and reduced tumor growth in mice. Together, our findings suggest that phosphorylation at distinct serine and tyrosine residues inhibits PDHA1 through distinct mechanisms to impact active site accessibility, which act in concert to regulate PDC activity and promote the Warburg effect. PMID:25104357

  16. Tyr-301 phosphorylation inhibits pyruvate dehydrogenase by blocking substrate binding and promotes the Warburg effect.

    PubMed

    Fan, Jun; Kang, Hee-Bum; Shan, Changliang; Elf, Shannon; Lin, Ruiting; Xie, Jianxin; Gu, Ting-Lei; Aguiar, Mike; Lonning, Scott; Chung, Tae-Wook; Arellano, Martha; Khoury, Hanna J; Shin, Dong M; Khuri, Fadlo R; Boggon, Titus J; Kang, Sumin; Chen, Jing

    2014-09-19

    The mitochondrial pyruvate dehydrogenase complex (PDC) plays a crucial role in regulation of glucose homoeostasis in mammalian cells. PDC flux depends on catalytic activity of the most important enzyme component pyruvate dehydrogenase (PDH). PDH kinase inactivates PDC by phosphorylating PDH at specific serine residues, including Ser-293, whereas dephosphorylation of PDH by PDH phosphatase restores PDC activity. The current understanding suggests that Ser-293 phosphorylation of PDH impedes active site accessibility to its substrate pyruvate. Here, we report that phosphorylation of a tyrosine residue Tyr-301 also inhibits PDH α 1 (PDHA1) by blocking pyruvate binding through a novel mechanism in addition to Ser-293 phosphorylation. In addition, we found that multiple oncogenic tyrosine kinases directly phosphorylate PDHA1 at Tyr-301, and Tyr-301 phosphorylation of PDHA1 is common in EGF-stimulated cells as well as diverse human cancer cells and primary leukemia cells from human patients. Moreover, expression of a phosphorylation-deficient PDHA1 Y301F mutant in cancer cells resulted in increased oxidative phosphorylation, decreased cell proliferation under hypoxia, and reduced tumor growth in mice. Together, our findings suggest that phosphorylation at distinct serine and tyrosine residues inhibits PDHA1 through distinct mechanisms to impact active site accessibility, which act in concert to regulate PDC activity and promote the Warburg effect.

  17. GFAT1 phosphorylation by AMPK promotes VEGF-induced angiogenesis.

    PubMed

    Zibrova, Darya; Vandermoere, Franck; Göransson, Olga; Peggie, Mark; Mariño, Karina V; Knierim, Anne; Spengler, Katrin; Weigert, Cora; Viollet, Benoit; Morrice, Nicholas A; Sakamoto, Kei; Heller, Regine

    2017-03-07

    Activation of AMP-activated protein kinase (AMPK) in endothelial cells regulates energy homeostasis, stress protection and angiogenesis, but the underlying mechanisms are incompletely understood. Using a label-free phosphoproteomic analysis, we identified glutamine:fructose-6-phosphate amidotransferase 1 (GFAT1) as an AMPK substrate. GFAT1 is the rate-limiting enzyme in the hexosamine biosynthesis pathway (HBP) and as such controls the modification of proteins by O-linked β-N-acetylglucosamine (O-GlcNAc). In the present study, we tested the hypothesis that AMPK controls O-GlcNAc levels and function of endothelial cells via GFAT1 phosphorylation using biochemical, pharmacological, genetic and in vitro angiogenesis approaches. Activation of AMPK in primary human endothelial cells by 5-aminoimidazole-4-carboxamide riboside (AICAR) or by vascular endothelial growth factor (VEGF) led to GFAT1 phosphorylation at serine 243. This effect was not seen when AMPK was down-regulated by siRNA. Upon AMPK activation, diminished GFAT activity and reduced O-GlcNAc levels were observed in endothelial cells containing wild-type (WT)-GFAT1 but not in cells expressing non-phosphorylatable S243A-GFAT1. Pharmacological inhibition or siRNA-mediated down-regulation of GFAT1 potentiated VEGF-induced sprouting, indicating that GFAT1 acts as a negative regulator of angiogenesis. In cells expressing S243A-GFAT1, VEGF-induced sprouting was reduced, suggesting that VEGF relieves the inhibitory action of GFAT1/HBP on angiogenesis via AMPK-mediated GFAT1 phosphorylation. Activation of GFAT1/HBP by high glucose led to impairment of vascular sprouting, whereas GFAT1 inhibition improved sprouting even if glucose level was high. Our findings provide novel mechanistic insights into the role of HBP in angiogenesis. They suggest that targeting AMPK in endothelium might help to ameliorate hyperglycaemia-induced vascular dysfunction associated with metabolic disorders.

  18. [Cholangiocarcinoma among printing workers].

    PubMed

    Kumagai, Shinji

    2014-02-01

    By June 2013, seventeen workers had suffered from intrahepatic or extrahepatic bile duct cancer (cholangiocarcinoma) in an offset proof-printing company in Osaka and nine of the workers had died. Ages at diagnosis were 25 to 45 years old. Known risk factors for cholangiocarcinoma were not found in the patients. All of the patients were exposed to 1,2-dichloropropane at high level for long-term and were diagnosed with cholangiocarcinoma 7 to 20 years after the first exposure. Twelve of the patients were also exposed to dichloromethane. The Japan Ministry of Health, Labour and Welfare recognized the cancer to be an occupational disease.

  19. Decrease of miR-622 expression promoted the proliferation, migration and invasion of cholangiocarcinoma cells by targeting regulation of c-Myc.

    PubMed

    Wu, Yi-Fei; Li, Zhuo-Ri; Cheng, Zhi-Qi; Yin, Xin-Min; Wu, Jin-Shu

    2017-09-26

    To explore the mechanism of miR-622 in regulating the proliferation, migration and invasion of cholangiocarcinoma (CCA) cells. Quantitative real-time PCR was conducted to measure the expression of miR-622 and c-Myc in CCA tissues and cell lines. Protein level of c-Myc was measured by Western blot. The effect of miR-622 on cell proliferation, migration and invasion was analyzed by MTT assay and Transwell chamber migration assay. Luciferase reporter assay was performed to measure the effect of miR-622 on c-Myc. miR-622 expression was downregulated in both CCA tissues and cell lines, while c-Myc expression was uregulated. Overexpression of miR-622 in CCA cells was statistically correlated with a decrease of cell proliferation, migration and invasion, while inhibition of miR-622 made an inverse result. We also proved c-Myc was identified as a target gene of miR-622 in CCA. Moreover, we found overexpression of c-Myc can strengthen the effects of miR-622 on the proliferation, migration and invasion of CCA cells. Decrease of miR-622 promotes the proliferation, migration and invasion of CCA cells by directly targeting c-Myc. Copyright © 2017. Published by Elsevier Masson SAS.

  20. Phosphorylation of PCNA by EGFR inhibits mismatch repair and promotes misincorporation during DNA synthesis

    PubMed Central

    Ortega, Janice; Li, Jessie Y.; Lee, Sanghee; Tong, Dan; Gu, Liya; Li, Guo-Min

    2015-01-01

    Proliferating cell nuclear antigen (PCNA) plays essential roles in eukaryotic cells during DNA replication, DNA mismatch repair (MMR), and other events at the replication fork. Earlier studies show that PCNA is regulated by posttranslational modifications, including phosphorylation of tyrosine 211 (Y211) by the epidermal growth factor receptor (EGFR). However, the functional significance of Y211-phosphorylated PCNA remains unknown. Here, we show that PCNA phosphorylation by EGFR alters its interaction with mismatch-recognition proteins MutSα and MutSβ and interferes with PCNA-dependent activation of MutLα endonuclease, thereby inhibiting MMR at the initiation step. Evidence is also provided that Y211-phosphorylated PCNA induces nucleotide misincorporation during DNA synthesis. These findings reveal a novel mechanism by which Y211-phosphorylated PCNA promotes cancer development and progression via facilitating error-prone DNA replication and suppressing the MMR function. PMID:25825764

  1. Tyr-94 Phosphorylation Inhibits Pyruvate Dehydrogenase Phosphatase 1 and Promotes Tumor Growth*

    PubMed Central

    Shan, Changliang; Kang, Hee-Bum; Elf, Shannon; Xie, Jianxin; Gu, Ting-Lei; Aguiar, Mike; Lonning, Scott; Hitosugi, Taro; Chung, Tae-Wook; Arellano, Martha; Khoury, Hanna J.; Shin, Dong M.; Khuri, Fadlo R.; Boggon, Titus J.; Fan, Jun

    2014-01-01

    Many cancer cells rely more on aerobic glycolysis (the Warburg effect) than mitochondrial oxidative phosphorylation and catabolize glucose at a high rate. Such a metabolic switch is suggested to be due in part to functional attenuation of mitochondria in cancer cells. However, how oncogenic signals attenuate mitochondrial function and promote the switch to glycolysis remains unclear. We previously reported that tyrosine phosphorylation activates and inhibits mitochondrial pyruvate dehydrogenase kinase (PDK) and phosphatase (PDP), respectively, leading to enhanced inhibitory serine phosphorylation of pyruvate dehydrogenase (PDH) and consequently inhibition of pyruvate dehydrogenase complex (PDC) in cancer cells. In particular, Tyr-381 phosphorylation of PDP1 dissociates deacetylase SIRT3 and recruits acetyltransferase ACAT1 to PDC, resulting in increased inhibitory lysine acetylation of PDHA1 and PDP1. Here we report that phosphorylation at another tyrosine residue, Tyr-94, inhibits PDP1 by reducing the binding ability of PDP1 to lipoic acid, which is covalently attached to the L2 domain of dihydrolipoyl acetyltransferase (E2) to recruit PDP1 to PDC. We found that multiple oncogenic tyrosine kinases directly phosphorylated PDP1 at Tyr-94, and Tyr-94 phosphorylation of PDP1 was common in diverse human cancer cells and primary leukemia cells from patients. Moreover, expression of a phosphorylation-deficient PDP1 Y94F mutant in cancer cells resulted in increased oxidative phosphorylation, decreased cell proliferation under hypoxia, and reduced tumor growth in mice. Together, our findings suggest that phosphorylation at different tyrosine residues inhibits PDP1 through independent mechanisms, which act in concert to regulate PDC activity and promote the Warburg effect. PMID:24962578

  2. Obesity and cholangiocarcinoma

    PubMed Central

    Parsi, Mansour A

    2013-01-01

    It is estimated that about half of the population in developed countries are either overweight or obese. In some developing nations obesity rates have increased to surpass those seen in Western countries. This rate increase in obesity has many implications as obesity has been associated with numerous negative health effects including increased risks of hypertension, diabetes, cardiovascular disease, stroke, liver disease, apnea, and some cancer types. Obesity is now considered to be one of the major public health concerns facing the society. Cholangiocarcinomas (bile duct cancers) are malignant tumors arising from cholangiocytes inside or outside of the liver. Although cholangiocarcinomas are relatively rare, they are highly lethal. The low survival rate associated with cholangiocarcinoma is due to the advanced stage of the disease at the time of diagnosis. Prevention is therefore especially important in this cancer type. Some data suggest that the incidence of cholangiocarcinoma in the western world is on the rise. Increasing rate of obesity may be one of the factors responsible for this increase. Determining whether obesity is a risk factor for cholangiocarcinoma has significant clinical and societal implications as obesity is both prevalent and modifiable. This paper seeks to provide a summary of the current knowledge linking obesity and cholangiocarcinoma, and encourage further research on this topic. PMID:23382624

  3. Phosphorylation is the switch that turns PEA-15 from tumor suppressor to tumor promoter

    PubMed Central

    Sulzmaier, Florian J.; Opoku-Ansah, John; Ramos, Joe W.

    2012-01-01

    Abnormal ERK signaling is implicated in many human diseases including cancer. This signaling cascade is a good target for the therapy of certain malignancies because of its important role in regulating cell proliferation and survival. The small phosphoprotein PEA-15 is a potent regulator of the ERK signaling cascade, and, by acting on this pathway, has been described to have both tumor-suppressor and tumor-promoter functions. However, the exact mechanism by which PEA-15 drives the outcome one way or the other remains unclear. We propose that the cellular environment is crucial in determining PEA-15 protein function by affecting the protein’s phosphorylation state. We hypothesize that only unphosphorylated PEA-15 can act as a tumor-suppressor and that phosphorylation alters the interaction with binding partners to promote tumor development. In order to use PEA-15 as a prognostic marker or therapeutic target it is therefore important to evaluate its phosphorylation status. PMID:22694972

  4. Tousled-like kinases phosphorylate Asf1 to promote histone supply during DNA replication

    NASA Astrophysics Data System (ADS)

    Klimovskaia, Ilnaz M.; Young, Clifford; Strømme, Caroline B.; Menard, Patrice; Jasencakova, Zuzana; Mejlvang, Jakob; Ask, Katrine; Ploug, Michael; Nielsen, Michael L.; Jensen, Ole N.; Groth, Anja

    2014-03-01

    During DNA replication, nucleosomes are rapidly assembled on newly synthesized DNA to restore chromatin organization. Asf1, a key histone H3-H4 chaperone required for this process, is phosphorylated by Tousled-like kinases (TLKs). Here, we identify TLK phosphorylation sites by mass spectrometry and dissect how phosphorylation has an impact on human Asf1 function. The divergent C-terminal tail of Asf1a is phosphorylated at several sites, and this is required for timely progression through S phase. Consistent with this, biochemical analysis of wild-type and phospho-mimetic Asf1a shows that phosphorylation enhances binding to histones and the downstream chaperones CAF-1 and HIRA. Moreover, we find that TLK phosphorylation of Asf1a is induced in cells experiencing deficiency of new histones and that TLK interaction with Asf1a involves its histone-binding pocket. We thus propose that TLK signalling promotes histone supply in S phase by targeting histone-free Asf1 and stimulating its ability to shuttle histones to sites of chromatin assembly.

  5. Hedgehog-regulated atypical PKC promotes phosphorylation and activation of Smoothened and Cubitus interruptus in Drosophila

    PubMed Central

    Jiang, Kai; Liu, Yajuan; Fan, Junkai; Epperly, Garretson; Gao, Tianyan; Jiang, Jin; Jia, Jianhang

    2014-01-01

    Smoothened (Smo) is essential for transduction of the Hedgehog (Hh) signal in both insects and vertebrates. Cell surface/cilium accumulation of Smo is thought to play an important role in Hh signaling, but how the localization of Smo is controlled remains poorly understood. In this study, we demonstrate that atypical PKC (aPKC) regulates Smo phosphorylation and basolateral accumulation in Drosophila wings. Inactivation of aPKC by either RNAi or a mutation inhibits Smo basolateral accumulation and attenuates Hh target gene expression. In contrast, expression of constitutively active aPKC elevates basolateral accumulation of Smo and promotes Hh signaling. The aPKC-mediated phosphorylation of Smo at Ser680 promotes Ser683 phosphorylation by casein kinase 1 (CK1), and these phosphorylation events elevate Smo activity in vivo. Moreover, aPKC has an additional positive role in Hh signaling by regulating the activity of Cubitus interruptus (Ci) through phosphorylation of the Zn finger DNA-binding domain. Finally, the expression of aPKC is up-regulated by Hh signaling in a Ci-dependent manner. Our findings indicate a direct involvement of aPKC in Hh signaling beyond its role in cell polarity. PMID:25349414

  6. Phosphorylation of histone H3 is functionally linked to retinoic acid receptor β promoter activation

    PubMed Central

    Lefebvre, Bruno; Ozato, Keiko; Lefebvre, Philippe

    2002-01-01

    Ligand-dependent transcriptional activation of retinoic acid receptors (RARs) is a multistep process culminating in the formation of a multimeric co-activator complex on regulated promoters. Several co-activator complexes harbor an acetyl transferase activity, which is required for retinoid-induced transcription of reporter genes. Using murine P19 embryonal carcinoma cells, we examined the relationship between histone post-translational modifications and activation of the endogenous RARβ2 promoter, which is under the control of a canonical retinoic acid response element and rapidly induced upon retinoid treatment. While histones H3 and H4 were constitutively acetylated at this promoter, retinoid agonists induced a rapid phosphorylation at Ser10 of histone H3. A retinoid antagonist, whose activity was independent of co-repressor binding to RAR, could oppose this agonist-induced H3 phosphorylation. Since such post-translational modifications were not observed at several other promoters, we conclude that histone H3 phosphorylation may be a molecular signature of the activated, retinoid-controlled mRARβ2 gene promoter. PMID:11897660

  7. Glucose-activated RUNX2 phosphorylation promotes endothelial cell proliferation and an angiogenic phenotype.

    PubMed

    Pierce, Adam D; Anglin, Ian E; Vitolo, Michele I; Mochin, Maria T; Underwood, Karen F; Goldblum, Simeon E; Kommineni, Sravya; Passaniti, Antonino

    2012-01-01

    The runt-related protein-2 (RUNX2) is a DNA-binding transcription factor that regulates bone formation, tumor cell metastasis, endothelial cell (EC) proliferation, and angiogenesis. RUNX2 DNA binding is glucose and cell cycle regulated. We propose that glucose may activate RUNX2 through changes in post-translational phosphorylation that are cell cycle-specific and will regulate EC function. Glucose increased cell cycle progression in EC through both G2/M and G1 phases with entry into S-phase occurring only in subconfluent cells. In the absence of nutrients and growth factors (starvation), subconfluent EC were delayed in G1 when RUNX2 expression was reduced. RUNX2 phosphorylation, activation of DNA binding, and pRb phosphorylation were stimulated by glucose and were necessary to promote cell cycle progression. Glucose increased RUNX2 localization at focal subnuclear sites, which co-incided with RUNX2 occupancy of the cyclin-dependent kinase (cdk) inhibitor p21(Cip1) promoter, a gene normally repressed by RUNX2. Mutation of the RUNX2 cdk phosphorylation site in the C-terminal domain (S451A.RUNX2) reduced RUNX2 phosphorylation and DNA binding. Expression of this cdk site mutant in EC inhibited glucose-stimulated differentiation (in vitro tube formation), monolayer wound healing, and proliferation. These results define a novel relationship between glucose-activated RUNX2 phosphorylation, cell cycle progression, and EC differentiation. These data suggest that inhibition of RUNX2 expression or DNA binding may be a useful strategy to inhibit EC proliferation in tumor angiogenesis.

  8. Phosphorylation-mediated activation of LDHA promotes cancer cell invasion and tumour metastasis.

    PubMed

    Jin, L; Chun, J; Pan, C; Alesi, G N; Li, D; Magliocca, K R; Kang, Y; Chen, Z G; Shin, D M; Khuri, F R; Fan, J; Kang, S

    2017-07-06

    Metastases remain the major cause of death from cancer. Recent molecular advances have highlighted the importance of metabolic alterations in cancer cells, including the Warburg effect that describes an increased glycolysis in cancer cells. However, how this altered metabolism contributes to tumour metastasis remains elusive. Here, we report that phosphorylation-induced activation of lactate dehydrogenase A (LDHA), an enzyme that catalyses the interconversion of pyruvate and lactate, promotes cancer cell invasion, anoikis resistance and tumour metastasis. We demonstrate that LDHA is phosphorylated at tyrosine 10 by upstream kinases, HER2 and Src. Targeting HER2 or Src attenuated LDH activity as well as invasive potential in head and neck cancer and breast cancer cells. Inhibition of LDH activity by small hairpin ribonucleic acid or expression of phospho-deficient LDHA Y10F sensitized the cancer cells to anoikis induction and resulted in attenuated cell invasion and elevated reactive oxygen species, whereas such phenotypes were reversed by its product lactate or antioxidant N-acetylcysteine, suggesting that Y10 phosphorylation-mediated LDHA activity promotes cancer cell invasion and anoikis resistance through redox homeostasis. In addition, LDHA knockdown or LDHA Y10F rescue expression in human cancer cells resulted in decreased tumour metastasis in xenograft mice. Furthermore, LDHA phosphorylation at Y10 positively correlated with progression of metastatic breast cancer in clinical patient tumour samples. Our findings demonstrate that LDHA phosphorylation and activation provide pro-invasive, anti-anoikis and pro-metastatic advantages to cancer cells, suggesting that Y10 phosphorylation of LDHA may represent a promising therapeutic target and a prognostic marker for metastatic human cancers.

  9. Hedgehog induces formation of PKA-Smoothened complexes to promote Smoothened phosphorylation and pathway activation

    PubMed Central

    Li, Shuang; Ma, Guoqiang; Wang, Bing; Jiang, Jin

    2015-01-01

    Hedgehog (Hh) is a secreted glycoprotein that binds its receptor Patched to activate the G protein-coupled receptor-like protein Smoothened (Smo). In Drosophila, protein kinase A (PKA) phosphorylates and activates Smo in cells stimulated with Hh. In unstimulated cells, PKA phosphorylates and inhibits the transcription factor Cubitus interruptus (Ci). Here, we found that in cells exposed to Hh, the catalytic subunit of PKA (PKAc) bound to the juxtamembrane region of the C terminus of Smo. PKA-mediated phosphorylation of Smo further enhanced its association with PKAc to form stable kinase-substrate complexes that promoted the PKA-mediated trans-phosphorylation of Smo dimers. We identified multiple basic residues in the C-terminus of Smo that were required for interaction with PKAc, Smo phosphorylation, and Hh pathway activation. Hh induced a switch from the association of PKAc with a cytosolic complex of Ci and the kinesin-like protein Costal2 (Cos2) to a membrane-bound Smo-Cos2 complex. Thus, our study uncovers a previously uncharacterized mechanism for regulation of PKA activity and demonstrates that the signal-regulated formation of kinase-substrate complexes plays a central role in Hh signal transduction. PMID:24985345

  10. promotes pheromone receptor polarization and yeast chemotropism by inhibiting receptor phosphorylation

    PubMed Central

    Ismael, Amber; Tian, Wei; Waszczak, Nicholas; Wang, Xin; Cao, Youfang; Suchkov, Dmitry; Bar, Eli; Metodiev, Metodi V.; Liang, Jie; Arkowitz, Robert; Stone, David E.

    2016-01-01

    Gradient-directed cell migration (chemotaxis) and growth (chemotropism) are universal processes, which are essential to the development and life cycles of all species. Cells use surface receptors to sense the shallow chemical gradients that elicit chemotaxis and chemotropism. Slight asymmetries in receptor activation are amplified by downstream signaling systems, which ultimately induce dynamic reorganization of the cytoskeleton. During the mating response of budding yeast, a model chemotropic system, the pheromone receptor on the plasma membrane polarizes to the side of the cell closest to the stimulus. Although receptor polarization occurs before and independently of actin-cable dependent vesicle delivery (directed secretion), it requires receptor internalization. Phosphorylation of pheromone receptors by yeast casein kinase 1 or 2 (Yck1/2) stimulates their internalization. We showed that the pheromone-responsive Gβγ dimer promotes the polarization of the pheromone receptor by interacting with Yck1/2 and locally inhibiting receptor phosphorylation. We also found that receptor phosphorylation is essential for chemotropism, independent of its role in inducing receptor internalization. A mathematical model supports the idea that the interaction between Gβγ and Yck1/2 results in differential phosphorylation and internalization of the pheromone receptor and accounts for its polarization before the initiation of directed secretion. PMID:27072657

  11. promotes pheromone receptor polarization and yeast chemotropism by inhibiting receptor phosphorylation.

    PubMed

    Ismael, Amber; Tian, Wei; Waszczak, Nicholas; Wang, Xin; Cao, Youfang; Suchkov, Dmitry; Bar, Eli; Metodiev, Metodi V; Liang, Jie; Arkowitz, Robert A; Stone, David E

    2016-04-12

    Gradient-directed cell migration (chemotaxis) and growth (chemotropism) are processes that are essential to the development and life cycles of all species. Cells use surface receptors to sense the shallow chemical gradients that elicit chemotaxis and chemotropism. Slight asymmetries in receptor activation are amplified by downstream signaling systems, which ultimately induce dynamic reorganization of the cytoskeleton. During the mating response of budding yeast, a model chemotropic system, the pheromone receptors on the plasma membrane polarize to the side of the cell closest to the stimulus. Although receptor polarization occurs before and independently of actin cable-dependent delivery of vesicles to the plasma membrane (directed secretion), it requires receptor internalization. Phosphorylation of pheromone receptors by yeast casein kinase 1 or 2 (Yck1/2) stimulates their internalization. We showed that the pheromone-responsive Gβγ dimer promotes the polarization of the pheromone receptor by interacting with Yck1/2 and locally inhibiting receptor phosphorylation. We also found that receptor phosphorylation is essential for chemotropism, independently of its role in inducing receptor internalization. A mathematical model supports the idea that the interaction between Gβγ and Yck1/2 results in differential phosphorylation and internalization of the pheromone receptor and accounts for its polarization before the initiation of directed secretion.

  12. Arsenic Inhibits DNA Mismatch Repair by Promoting EGFR Expression and PCNA Phosphorylation*

    PubMed Central

    Tong, Dan; Ortega, Janice; Kim, Christine; Huang, Jian; Gu, Liya; Li, Guo-Min

    2015-01-01

    Both genotoxic and non-genotoxic chemicals can act as carcinogens. However, while genotoxic compounds lead directly to mutations that promote unregulated cell growth, the mechanism by which non-genotoxic carcinogens lead to cellular transformation is poorly understood. Using a model non-genotoxic carcinogen, arsenic, we show here that exposure to arsenic inhibits mismatch repair (MMR) in human cells, possibly through its ability to stimulate epidermal growth factor receptor (EGFR)-dependent tyrosine phosphorylation of proliferating cellular nuclear antigen (PCNA). HeLa cells exposed to exogenous arsenic demonstrate a dose- and time-dependent increase in the levels of EGFR and tyrosine 211-phosphorylated PCNA. Cell extracts derived from arsenic-treated HeLa cells are defective in MMR, and unphosphorylated recombinant PCNA restores normal MMR activity to these extracts. These results suggest a model in which arsenic induces expression of EGFR, which in turn phosphorylates PCNA, and phosphorylated PCNA then inhibits MMR, leading to increased susceptibility to carcinogenesis. This study suggests a putative novel mechanism of action for arsenic and other non-genotoxic carcinogens. PMID:25907674

  13. Promotion of beta-glucan synthase activity in corn microsomal membranes by calcium and protein phosphorylation

    NASA Technical Reports Server (NTRS)

    Paliyath, G.; Poovaiah, B. W.

    1988-01-01

    Regulation of the activity of beta-glucan synthase was studied using microsomal preparations from corn coleoptiles. The specific activity as measured by the incorporation of glucose from uridine diphospho-D-[U-14C]glucose varied between 5 to 15 pmol (mg protein)-1 min-1. Calcium promoted beta-glucan synthase activity and the promotion was observed at free calcium concentrations as low as 1 micromole. Kinetic analysis of substrate-velocity curve showed an apparent Km of 1.92 x 10(-4) M for UDPG. Calcium increased the Vmax from 5.88 x 10(-7) mol liter-1 min-1 in the absence of calcium to 9.52 x 10(-7) mol liter-1 min-1 and 1.66 x 10(-6) mol liter-1 min-1 in the presence of 0.5 mM and 1 mM calcium, respectively. The Km values remained the same under these conditions. Addition of ATP further increased the activity above the calcium-promoted level. Sodium fluoride, a phosphoprotein phosphatase inhibitor, promoted glucan synthase activity indicating that phosphorylation and dephosphorylation are involved in the regulation of the enzyme activity. Increasing the concentration of sodium fluoride from 0.25 mM to 10 mM increased glucan synthase activity five-fold over the + calcium + ATP control. Phosphorylation of membrane proteins also showed a similar increase under these conditions. Calmodulin, in the presence of calcium and ATP stimulated glucan synthase activity substantially, indicating that calmodulin could be involved in the calcium-dependent phosphorylation and promotion of beta-glucan synthase activity. The role of calcium in mediating auxin action is discussed.

  14. Promotion of beta-glucan synthase activity in corn microsomal membranes by calcium and protein phosphorylation

    NASA Technical Reports Server (NTRS)

    Paliyath, G.; Poovaiah, B. W.

    1988-01-01

    Regulation of the activity of beta-glucan synthase was studied using microsomal preparations from corn coleoptiles. The specific activity as measured by the incorporation of glucose from uridine diphospho-D-[U-14C]glucose varied between 5 to 15 pmol (mg protein)-1 min-1. Calcium promoted beta-glucan synthase activity and the promotion was observed at free calcium concentrations as low as 1 micromole. Kinetic analysis of substrate-velocity curve showed an apparent Km of 1.92 x 10(-4) M for UDPG. Calcium increased the Vmax from 5.88 x 10(-7) mol liter-1 min-1 in the absence of calcium to 9.52 x 10(-7) mol liter-1 min-1 and 1.66 x 10(-6) mol liter-1 min-1 in the presence of 0.5 mM and 1 mM calcium, respectively. The Km values remained the same under these conditions. Addition of ATP further increased the activity above the calcium-promoted level. Sodium fluoride, a phosphoprotein phosphatase inhibitor, promoted glucan synthase activity indicating that phosphorylation and dephosphorylation are involved in the regulation of the enzyme activity. Increasing the concentration of sodium fluoride from 0.25 mM to 10 mM increased glucan synthase activity five-fold over the + calcium + ATP control. Phosphorylation of membrane proteins also showed a similar increase under these conditions. Calmodulin, in the presence of calcium and ATP stimulated glucan synthase activity substantially, indicating that calmodulin could be involved in the calcium-dependent phosphorylation and promotion of beta-glucan synthase activity. The role of calcium in mediating auxin action is discussed.

  15. Leptin Enhances Cholangiocarcinoma Cell Growth

    PubMed Central

    Fava, Giammarco; Alpini, Gianfranco; Rychlicki, Chiara; Saccomanno, Stefania; DeMorrow, Sharon; Trozzi, Luciano; Candelaresi, Cinzia; Venter, Julie; Di Sario, Antonio; Marzioni, Marco; Bearzi, Italo; Glaser, Shannon; Alvaro, Domenico; Marucci, Luca; Francis, Heather; Svegliati-Baroni, Gianluca; Benedetti, Antonio

    2008-01-01

    Cholangiocarcinoma is a strongly aggressive malignancy with a very poor prognosis. Effective therapeutic strategies are lacking because molecular mechanisms regulating cholangiocarcinoma cell growth are unknown. Furthermore, experimental in vivo animal models useful to study the pathophysiologic mechanisms of malignant cholangiocytes are lacking. Leptin, the hormone regulating caloric homeostasis, which is increased in obese patients, stimulates the growth of several cancers, such as hepatocellular carcinoma. The aim of this study was to define if leptin stimulates cholangiocarcinoma growth. We determined the expression of leptin receptors in normal and malignant human cholangiocytes. Effects on intrahepatic cholangiocarcinoma (HuH-28) cell proliferation, migration, and apoptosis of the in vitro exposure to leptin, together with the intracellular pathways, were then studied. Moreover, cholangiocarcinoma was experimentally induced in obese fa/fa Zucker rats, a genetically established animal species with faulty leptin receptors, and in their littermates by chronic feeding with thioacetamide, a potent carcinogen. After 24 weeks, the effect of leptin on cholangiocarcinoma development and growth was assessed. Normal and malignant human cholangiocytes express leptin receptors. Leptin increased the proliferation and the metastatic potential of cholangiocarcinoma cells in vitro through a signal transducers and activators of transcription 3–dependent activation of extracellular signal-regulated kinase 1/2. Leptin increased the growth and migration, and was antiapoptotic for cholangiocarcinoma cells. Moreover, the loss of leptin function reduced the development and the growth of cholangiocarcinoma. The experimental carcinogenesis model induced by thioacetamide administration is a valid and reproducible method to study cholangiocarcinoma pathobiology. Modulation of the leptin-mediated signal could be considered a valid tool for the prevention and treatment of

  16. ATM-Dependent Phosphorylation of MEF2D Promotes Neuronal Survival after DNA Damage

    PubMed Central

    Chan, Shing Fai; Sances, Sam; Brill, Laurence M.; Okamoto, Shu-ichi; Zaidi, Rameez; McKercher, Scott R.; Akhtar, Mohd W.; Nakanishi, Nobuki

    2014-01-01

    Mutations in the ataxia telangiectasia mutated (ATM) gene, which encodes a kinase critical for the normal DNA damage response, cause the neurodegenerative disorder ataxia-telangiectasia (AT). The substrates of ATM in the brain are poorly understood. Here we demonstrate that ATM phosphorylates and activates the transcription factor myocyte enhancer factor 2D (MEF2D), which plays a critical role in promoting survival of cerebellar granule cells. ATM associates with MEF2D after DNA damage and phosphorylates the transcription factor at four ATM consensus sites. Knockdown of endogenous MEF2D with a short-hairpin RNA (shRNA) increases sensitivity to etoposide-induced DNA damage and neuronal cell death. Interestingly, substitution of endogenous MEF2D with an shRNA-resistant phosphomimetic MEF2D mutant protects cerebellar granule cells from cell death after DNA damage, whereas an shRNA-resistant nonphosphorylatable MEF2D mutant does not. In vivo, cerebella in Mef2d knock-out mice manifest increased susceptibility to DNA damage. Together, our results show that MEF2D is a substrate for phosphorylation by ATM, thus promoting survival in response to DNA damage. Moreover, dysregulation of the ATM–MEF2D pathway may contribute to neurodegeneration in AT. PMID:24672010

  17. CSK-Mediated c-Jun Phosphorylation Promotes c-Jun Degradation and Inhibits Cell Transformation

    PubMed Central

    Zhu, Feng; Choi, Bu Young; Ma, Wei-Ya; Zhao, Zhongliang; Zhang, Yiguo; Cho, Yong Yeon; Choi, Hong Seok; Imamoto, Akira; Bode, Ann M.; Dong, Zigang

    2006-01-01

    The oncoprotein c-Jun is a component of the activator protein-1 (AP-1) transcription factor complex, which is involved in cellular proliferation, transformation and death. The stabilization of c-Jun is critically important for its function. Phosphorylation of c-Jun by c-Jun N-terminal kinase 1 (JNK1) and extracellular signal-regulated protein kinases (ERKs) reduces c-Jun ubiquitination resulting in increased stabilization of c-Jun. In this report, we showed that C-terminal Src kinase (CSK) binds with and phosphorylates c-Jun at Y26 and Y170. Phosphorylation of c-Jun by CSK, in opposition to JNK1 and ERKs, promoted c-Jun degradation and reduced stability. By promoting c-Jun degradation, CSK helps to maintain a low steady-state level of c-Jun, thereby inhibiting AP-1 activity and cell transformation caused by c-Jun. These results indicated that this function of CSK controls cell proliferation under normal growth conditions and may have implications for CSK loss of function in carcinogenesis. PMID:16740711

  18. ATM-dependent phosphorylation of MEF2D promotes neuronal survival after DNA damage.

    PubMed

    Chan, Shing Fai; Sances, Sam; Brill, Laurence M; Okamoto, Shu-Ichi; Zaidi, Rameez; McKercher, Scott R; Akhtar, Mohd W; Nakanishi, Nobuki; Lipton, Stuart A

    2014-03-26

    Mutations in the ataxia telangiectasia mutated (ATM) gene, which encodes a kinase critical for the normal DNA damage response, cause the neurodegenerative disorder ataxia-telangiectasia (AT). The substrates of ATM in the brain are poorly understood. Here we demonstrate that ATM phosphorylates and activates the transcription factor myocyte enhancer factor 2D (MEF2D), which plays a critical role in promoting survival of cerebellar granule cells. ATM associates with MEF2D after DNA damage and phosphorylates the transcription factor at four ATM consensus sites. Knockdown of endogenous MEF2D with a short-hairpin RNA (shRNA) increases sensitivity to etoposide-induced DNA damage and neuronal cell death. Interestingly, substitution of endogenous MEF2D with an shRNA-resistant phosphomimetic MEF2D mutant protects cerebellar granule cells from cell death after DNA damage, whereas an shRNA-resistant nonphosphorylatable MEF2D mutant does not. In vivo, cerebella in Mef2d knock-out mice manifest increased susceptibility to DNA damage. Together, our results show that MEF2D is a substrate for phosphorylation by ATM, thus promoting survival in response to DNA damage. Moreover, dysregulation of the ATM-MEF2D pathway may contribute to neurodegeneration in AT.

  19. TFIIH phosphorylation of the Pol II CTD stimulates Mediator dissociation from the preinitiation complex and promoter escape

    PubMed Central

    Wong, Koon Ho; Jin, Yi; Struhl, Kevin

    2014-01-01

    The transition between transcriptional initiation and elongation by RNA polymerase (Pol) II is associated with phosphorylation of its C-terminal tail (CTD). Depletion of Kin28, the TFIIH subunit that phosphorylates the CTD, does not affect elongation but causes Pol II occupancy profiles to shift upstream in a FACT-independent manner indicative of a defect in promoter escape. Stronger defects in promoter escape are linked to stronger effects on preinitiation complex formation and transcription, suggesting that impairment in promoter escape results in premature dissociation of general factors and Pol II near the promoter. Kin28 has a stronger effect on genes whose transcription is dependent on SAGA as opposed to TFIID. Strikingly, Kin28 depletion causes a dramatic increase in Mediator at the core promoter. These observations suggest that TFIIH phosphorylation of the CTD causes Mediator dissociation, thereby permitting rapid promoter escape of Pol II from the preinitiation complex. PMID:24746699

  20. Current update on combined hepatocellular-cholangiocarcinoma

    PubMed Central

    Maximin, Suresh; Ganeshan, Dhakshina Moorthy; Shanbhogue, Alampady K.; Dighe, Manjiri K.; Yeh, Matthew M.; Kolokythas, Orpheus; Bhargava, Puneet; Lalwani, Neeraj

    2014-01-01

    Combined hepatocellular-cholangiocarcinoma is a rare but unique primary hepatic tumor with characteristic histology and tumor biology. Recent development in genetics and molecular biology support the fact that combined hepatocellular-cholangiocarcinoma is closely linked with cholangiocarcinoma, rather than hepatocellular carcinoma. Combined hepatocellular cholangiocarcinoma tends to present with an more aggressive behavior and a poorer prognosis than either hepatocellular carcinoma or cholangiocarcinoma. An accurate preoperative diagnosis and aggressive treatment planning can play crucial roles in appropriate patient management. PMID:26937426

  1. RASSF4 promotes EV71 replication to accelerate the inhibition of the phosphorylation of AKT.

    PubMed

    Zhang, Fengfeng; Liu, Yongjuan; Chen, Xiong; Dong, Lanlan; Zhou, Bingfei; Cheng, Qingqing; Han, Song; Liu, Zhongchun; Peng, Biwen; He, Xiaohua; Liu, Wanhong

    2015-03-20

    Enterovirus 71 (EV71) is a neurotropic virus that causes hand, foot and mouth disease (HFMD), occasionally leading to death. As a member of the RAS association domain family (RASSFs), RASSF4 plays important roles in cell death, tumor development and signal transduction. However, little is known about the relationship between RASSF4 and EV71. Our study reveals for the first time that RASSF4 promotes EV71 replication and then accelerates AKT phosphorylation inhibition in EV71-infected 293T cells, suggesting that RASSF4 may be a potential new target for designing therapeutic measures to prevent and control EV71 infection.

  2. Phosphorylation promotes Al(iii) binding to proteins: GEGEGSGG as a case study.

    PubMed

    Grande-Aztatzi, Rafael; Formoso, Elena; Mujika, Jon I; Ugalde, Jesus M; Lopez, Xabier

    2016-03-14

    Aluminum, the third most abundant element in the Earth's crust and one of the key industrial components of our everyday life, has been associated with several neurodegenerative diseases due to its ability to promote neurofilament tangles and β-amyloid peptide aggregation. However, the experimental characterization of aluminum speciation in vivo is a difficult task. In the present study, we develop a theoretical protocol that combines molecular dynamics simulations, clustering of structures, and density functional theory for the characterization of the binding of aluminum to the synthetic neurofilament analogue octapeptide GEGEGSGG and its phosphorylated variant. Our protocol is tested with respect to previous NMR experimental data, which allows for a full interpretation of the experimental information available and its relationship with key thermodynamic quantities. Our results demonstrate the importance of phosphorylation in the ability of a peptide to bind to aluminum. Thus, phosphorylation: (i) changes the binding pattern of aluminum to GEGEGSGG, shifting the preferential binding site from the C-terminal to S6(P); (ii) increases the binding affinity by a factor of around 15 kcal mol(-1) in free energy; and (iii) may cause significant changes in the secondary structure and stiffness of the polypeptide chain, specially in the case of bidentate binding modes. Our results shed light on the possibility of aluminum to induce aggregation of β-amyloid proteins and neurofilament tangles.

  3. Protein kinase Cζ phosphorylates occludin and promotes assembly of epithelial tight junctions.

    PubMed

    Jain, Suneet; Suzuki, Takuya; Seth, Ankur; Samak, Geetha; Rao, Radhakrishna

    2011-07-15

    Protein kinases play an important role in the regulation of epithelial tight junctions. In the present study, we investigated the role of PKCζ (protein kinase Cζ) in tight junction regulation in Caco-2 and MDCK (Madin-Darby canine kidney) cell monolayers. Inhibition of PKCζ by a specific PKCζ pseudosubstrate peptide results in redistribution of occludin and ZO-1 (zona occludens 1) from the intercellular junctions and disruption of barrier function without affecting cell viability. Reduced expression of PKCζ by antisense oligonucleotide or shRNA (short hairpin RNA) also results in compromised tight junction integrity. Inhibition or knockdown of PKCζ delays calcium-induced assembly of tight junctions. Tight junction disruption by PKCζ pseudosubstrate is associated with the dephosphorylation of occludin and ZO-1 on serine and threonine residues. PKCζ directly binds to the C-terminal domain of occludin and phosphorylates it on threonine residues. Thr403, Thr404, Thr424 and Thr438 in the occludin C-terminal domain are the predominant sites of PKCζ-dependent phosphorylation. A T424A or T438A mutation in full-length occludin delays its assembly into the tight junctions. Inhibition of PKCζ also induces redistribution of occludin and ZO-1 from the tight junctions and dissociates these proteins from the detergent-insoluble fractions in mouse ileum. The present study demonstrates that PKCζ phosphorylates occludin on specific threonine residues and promotes assembly of epithelial tight junctions.

  4. ERK phosphorylation of MED14 in promoter complexes during mitogen-induced gene activation by Elk-1

    PubMed Central

    Galbraith, Matthew D.; Saxton, Janice; Li, Li; Shelton, Samuel J.; Zhang, Hongmei; Espinosa, Joaquin M.; Shaw, Peter E.

    2013-01-01

    The ETS domain transcription factor Elk-1 stimulates expression of immediate early genes (IEGs) in response to mitogens. These events require phosphorylation of Elk-1 by extracellular signal-regulated kinase (ERK) and phosphorylation-dependent interaction of Elk-1 with co-activators, including histone acetyltransferases and the Mediator complex. Elk-1 also recruits ERK to the promoters of its target genes, suggesting that ERK phosphorylates additional substrates in transcription complexes at mitogen-responsive promoters. Here we report that MED14, a core subunit of the Mediator, is a bona fide ERK substrate and identify serine 986 (S986) within a serine-proline rich region of MED14 as the major ERK phosphorylation site. Mitogens induced phosphorylation of MED14 on S986 at IEG promoters; RNAi knockdown of MED14 reduced CDK8 and RNA polymerase II (RNAPII) recruitment, RNAPII C-terminal domain phosphorylation and impaired activation of IEG transcription. A single alanine substitution at S986 reduced activation of an E26 (ETS)-responsive reporter by oncogenic Ras and mitogen-induced, Elk-1-dependent transcription, whereas activities of other transcriptional activators were unaffected. We also demonstrate that Elk-1 can associate with MED14 independently of MED23, which may facilitate phosphorylation of MED14 by ERK to impart a positive and selective impact on mitogen-responsive gene expression. PMID:24049075

  5. ERK phosphorylation of MED14 in promoter complexes during mitogen-induced gene activation by Elk-1.

    PubMed

    Galbraith, Matthew D; Saxton, Janice; Li, Li; Shelton, Samuel J; Zhang, Hongmei; Espinosa, Joaquin M; Shaw, Peter E

    2013-12-01

    The ETS domain transcription factor Elk-1 stimulates expression of immediate early genes (IEGs) in response to mitogens. These events require phosphorylation of Elk-1 by extracellular signal-regulated kinase (ERK) and phosphorylation-dependent interaction of Elk-1 with co-activators, including histone acetyltransferases and the Mediator complex. Elk-1 also recruits ERK to the promoters of its target genes, suggesting that ERK phosphorylates additional substrates in transcription complexes at mitogen-responsive promoters. Here we report that MED14, a core subunit of the Mediator, is a bona fide ERK substrate and identify serine 986 (S986) within a serine-proline rich region of MED14 as the major ERK phosphorylation site. Mitogens induced phosphorylation of MED14 on S986 at IEG promoters; RNAi knockdown of MED14 reduced CDK8 and RNA polymerase II (RNAPII) recruitment, RNAPII C-terminal domain phosphorylation and impaired activation of IEG transcription. A single alanine substitution at S986 reduced activation of an E26 (ETS)-responsive reporter by oncogenic Ras and mitogen-induced, Elk-1-dependent transcription, whereas activities of other transcriptional activators were unaffected. We also demonstrate that Elk-1 can associate with MED14 independently of MED23, which may facilitate phosphorylation of MED14 by ERK to impart a positive and selective impact on mitogen-responsive gene expression.

  6. Survivin promotes oxidative phosphorylation, subcellular mitochondrial repositioning, and tumor cell invasion

    PubMed Central

    Rivadeneira, Dayana B.; Caino, M. Cecilia; Seo, Jae Ho; Angelin, Alessia; Wallace, Douglas C.; Languino, Lucia R.; Altieri, Dario C.

    2015-01-01

    Survivin promotes cell division and suppresses apoptosis in many human cancers, and increased abundance correlates with metastasis and poor prognosis. Here, we showed that a pool of survivin that localized to the mitochondria of certain tumor cell lines enhanced the stability of oxidative phosphorylation Complex II, which promoted cellular respiration. Survivin also supported the subcellular trafficking of mitochondria to the cortical cytoskeleton of tumor cells, which was associated with increased membrane ruffling, increased focal adhesion complex turnover, and increased tumor cell migration and invasion in cultured cells, and enhanced metastatic dissemination in vivo. Therefore, we found that mitochondrial respiration enhanced by survivin contributes to cancer metabolism, and relocalized mitochondria may provide a “regional” energy source to fuel tumor cell invasion and metastasis. PMID:26268608

  7. Resection of Perihilar Cholangiocarcinoma.

    PubMed

    Hartog, Hermien; Ijzermans, Jan N M; van Gulik, Thomas M; Groot Koerkamp, Bas

    2016-04-01

    Perihilar cholangiocarcinoma presents at the biliary and vascular junction of the hepatic hilum with a tendency to extend longitudinally into segmental bile ducts. Most patients show metastatic or unresectable disease at time of presentation or surgical exploration. In patients eligible for surgical resection, challenges are to achieve negative bile duct margins, adequate liver remnant function, and adequate portal and arterial inflow to the liver remnant. Surgical treatment is characterized by high rates of postoperative morbidity and mortality. This article reviews the various strategies and techniques, the role of staging laparoscopy, intraoperative frozen section, caudate lobectomy, and vascular reconstruction.

  8. Axl Phosphorylates Elmo Scaffold Proteins To Promote Rac Activation and Cell Invasion

    PubMed Central

    Abu-Thuraia, Afnan; Gauthier, Rosemarie; Chidiac, Rony; Fukui, Yoshinori; Screaton, Robert A.; Gratton, Jean-Philippe

    2014-01-01

    The receptor tyrosine kinase Axl contributes to cell migration and invasion. Expression of Axl correlates with metastatic progression in cancer patients, yet the specific signaling events promoting invasion downstream of Axl are poorly defined. Herein, we report Elmo scaffolds to be direct substrates and binding partners of Axl. Elmo proteins are established to interact with Dock family guanine nucleotide exchange factors to control Rac-mediated cytoskeletal dynamics. Proteomics and mutagenesis studies reveal that Axl phosphorylates Elmo1/2 on a conserved carboxyl-terminal tyrosine residue. Upon Gas6-dependent activation of Axl, endogenous Elmo2 becomes phosphorylated on Tyr-713 and enters into a physical complex with Axl in breast cancer cells. Interfering with Elmo2 expression prevented Gas6-induced Rac1 activation in breast cancer cells. Similarly to blocking of Axl, Elmo2 knockdown or pharmacological inhibition of Dock1 abolishes breast cancer cell invasion. Interestingly, Axl or Elmo2 knockdown diminishes breast cancer cell proliferation. Rescue of Elmo2 knockdown cells with the wild-type protein but not with Elmo2 harboring Tyr-713-Phe mutations restores cell invasion and cell proliferation. These results define a new mechanism by which Axl promotes cell proliferation and invasion and identifies inhibition of the Elmo-Dock pathway as a potential therapeutic target to stop Axl-induced metastases. PMID:25332238

  9. Phosphoryl Transfer Processes Promoted by a Trifunctional Calix[4]arene Inspired by DNA Topoisomerase I.

    PubMed

    Salvio, Riccardo; Volpi, Stefano; Cacciapaglia, Roberta; Sansone, Francesco; Mandolini, Luigi; Casnati, Alessandro

    2016-10-07

    The cone-calix[4]arene derivative (1H3)(2+), decorated at the upper rim with two guanidinium units and a phenolic hydroxyl in an ABAH functionalization pattern, effectively promotes the cleavage of the DNA model compound bis(p-nitrophenyl) phosphate (BNPP) in 80% DMSO solution at pH values in the range 8.5-12.0. The pH dependence of the kinetics was found to be fully consistent with the results of the potentiometric titration of the triprotic acid (1H3)(2+). At pH 9.5, the rate enhancement of p-nitrophenol liberation from BNPP relative to background hydrolysis is 6.5 × 10(4)-fold at 1 mM concentration of the calix[4]arene derivative. Experimental data clearly point to the effective cooperation of the three active units and to the involvement of the phenolate moiety as a nucleophile in the phosphoryl transfer step. Subsequent liberation of a second equivalent of p-nitrophenol from the phosphorylated calixarene intermediate is conceivably promoted by the "built-in" guanidine/guanidinium catalytic dyad.

  10. Ricolinostat, Gemcitabine Hydrochloride, and Cisplatin in Treating Patients With Unresectable or Metastatic Cholangiocarcinoma

    ClinicalTrials.gov

    2016-08-02

    Non-Resectable Cholangiocarcinoma; Recurrent Cholangiocarcinoma; Stage III Extrahepatic Bile Duct Cancer; Stage III Intrahepatic Cholangiocarcinoma; Stage IIIA Hilar Cholangiocarcinoma; Stage IIIB Hilar Cholangiocarcinoma; Stage IVA Extrahepatic Bile Duct Cancer; Stage IVA Hilar Cholangiocarcinoma; Stage IVA Intrahepatic Cholangiocarcinoma; Stage IVB Extrahepatic Bile Duct Cancer; Stage IVB Hilar Cholangiocarcinoma; Stage IVB Intrahepatic Cholangiocarcinoma; Unresectable Extrahepatic Bile Duct Carcinoma

  11. Monoamine oxidase A expression is suppressed in human cholangiocarcinoma via coordinated epigenetic and IL-6-driven events

    PubMed Central

    Huang, Li; Frampton, Gabriel; Rao, Arundhati; Zhang, Kun-song; Chen, Wei; Lai, Jia-ming; Yin, Xiao-yu; Walker, Kimberly; Culbreath, Brianne; Leyva-Illades, Dinorah; Quinn, Matthew; McMillin, Matthew; Bradley, Michelle; Liang, Li-Jian; DeMorrow, Sharon

    2014-01-01

    Objectives The secretion of dopamine and serotonin is increased in cholangiocarcinoma, which has growth-promoting effects. Monoamine oxidase A (MAOA), the degradation enzyme of serotonin and dopamine, is suppressed in cholangiocarcinoma via an unknown mechanism. The aims of this study were to (i) correlate MAOA immunoreactivity with pathophysiological parameters of cholangiocarcinoma, (ii) determine the mechanism by which MAOA expression is suppressed and (iii) evaluate the consequences of restored MAOA expression in cholangiocarcinoma. Design MAOA expression was assessed in cholangiocarcinoma and non-malignant controls. The control of MAOA expression by promoter hypermethylation was evaluated and the contribution of IL-6 signaling to the suppression of MAOA expression was determined. The effects of MAOA overexpression on cholangiocarcinoma growth and invasion were also assessed. Results MAOA expression is correlated with differentiation, invasion and survival in cholangiocarcinoma. The MAOA promoter was hypermethylated immediately upstream of the start codon in cholangiocarcinoma samples and cell lines but not in non-malignant counterparts. IL-6 signaling also decreased MAOA expression via a mechanism independent of hypermethylation, involving the regulation of the balance between SP-1 transcriptional activity and its inhibitor, R1 repressor. Inhibition of both IL-6 signaling and DNA methylation restored MAOA levels to those observed in cholangiocytes. Forced MAOA overexpression inhibited cholangiocarcinoma growth and invasion. Conclusions MAOA expression is suppressed by the coordinated control of promoter hypermethylation and IL-6 signaling. MAOA may be a useful prognostic marker in the management of cholangiocarcinoma, and therapies designed to increase MAOA expression might prove beneficial in the treatment of cholangiocarcinoma. PMID:22906985

  12. Intrahepatic cholangiocarcinoma: current perspectives

    PubMed Central

    Buettner, Stefan; van Vugt, Jeroen LA; IJzermans, Jan NM; Groot Koerkamp, Bas

    2017-01-01

    Intrahepatic cholangiocarcinoma (ICC) is the second most common malignancy arising from the liver. ICC makes up about 10% of all cholangiocarcinomas. It arises from the peripheral bile ducts within the liver parenchyma, proximal to the secondary biliary radicals. Histologically, the majority of ICCs are adenocarcinomas. Only a minority of patients (15%) present with resectable disease, with a median survival of less than 3 years. Multidisciplinary management of ICC is complicated by large differences in disease course for individual patients both across and within tumor stages. Risk models and nomograms have been developed to more accurately predict survival of individual patients based on clinical parameters. Predictive risk factors are necessary to improve patient selection for systemic treatments. Molecular differences between tumors, such as in the epidermal growth factor receptor status, are promising, but their clinical applicability should be validated. For patients with locally advanced disease, several treatment strategies are being evaluated. Both hepatic arterial infusion chemotherapy with floxuridine and yttrium-90 embolization aim to downstage locally advanced ICC. Selected patients have resectable disease after downstaging, and other patients might benefit because of postponing widespread dissemination and biliary obstruction. PMID:28260927

  13. Warts phosphorylates Mud to promote Pins-mediated mitotic spindle orientation in Drosophila independent of Yorkie

    PubMed Central

    Dewey, Evan B.; Sanchez, Desiree; Johnston, Christopher A.

    2015-01-01

    SUMMARY Multicellular animals have evolved conserved signaling pathways that translate cell polarity cues into mitotic spindle positioning to control the orientation of cell division within complex tissue structures. These oriented cell divisions are essential for the development of cell diversity and the maintenance of tissue homeostasis. Despite intense efforts, the molecular mechanisms that control spindle orientation remain incompletely defined. Here we describe a role for the Hippo (Hpo) kinase complex in promoting Partner of Inscuteable (Pins)-mediated spindle orientation. Knockdown of Hpo, Salvador (Sav), or Warts (Wts) each result in a partial loss of spindle orientation, a phenotype previously described following loss of the Pins-binding protein Mushroom body defect (Mud). Similar to orthologs spanning yeast to mammals, Wts kinase localizes to mitotic spindle poles, a prominent site of Mud localization. Wts directly phosphorylates Mud in vitro within its C-terminal coiled-coil domain. This Mud coiled-coil domain directly binds the adjacent Pins-binding domain to dampen the Pins/Mud interaction, and Wts-mediated phosphorylation uncouples this intramolecular Mud interaction. Loss of Wts prevents cortical Pins/Mud association without affecting Mud accumulation at spindle poles, suggesting phosphorylation acts as a molecular switch to specifically activate cortical Mud function. Finally, loss of Wts in Drosophila imaginal disc epithelial cells results in diminished cortical Mud and defective planar spindle orientation. Our results provide new insights into the molecular basis for dynamic regulation of the cortical Pins/Mud spindle positioning complex and highlight a novel link with an essential, evolutionarily-conserved cell proliferation pathway. PMID:26592339

  14. Src-dependent phosphorylation of caveolin-1 Tyr-14 promotes swelling and release of caveolae

    PubMed Central

    Zimnicka, Adriana M.; Husain, Yawer S.; Shajahan, Ayesha N.; Sverdlov, Maria; Chaga, Oleg; Chen, Zhenlong; Toth, Peter T.; Klomp, Jennifer; Karginov, Andrei V.; Tiruppathi, Chinnaswamy; Malik, Asrar B.; Minshall, Richard D.

    2016-01-01

    Caveolin 1 (Cav1) is a required structural component of caveolae, and its phosphorylation by Src is associated with an increase in caveolae-mediated endocytosis. Here we demonstrate, using quantitative live-cell 4D, TIRF, and FRET imaging, that endocytosis and trafficking of caveolae are associated with a Cav1 Tyr-14 phosphorylation-dependent conformational change, which spatially separates, or loosens, Cav1 molecules within the oligomeric caveolar coat. When tracked by TIRF and spinning-disk microscopy, cells expressing phosphomimicking Cav1 (Y14D) mutant formed vesicles that were greater in number and volume than with Y14F-Cav1-GFP. Furthermore, we observed in HEK cells cotransfected with wild-type, Y14D, or Y14F Cav1-CFP and -YFP constructs that FRET efficiency was greater with Y14F pairs than with Y14D, indicating that pY14-Cav1 regulates the spatial organization of Cav1 molecules within the oligomer. In addition, albumin-induced Src activation or direct activation of Src using a rapamycin-inducible Src construct (RapR-Src) led to an increase in monomeric Cav1 in Western blots, as well as a simultaneous increase in vesicle number and decrease in FRET intensity, indicative of a Src-mediated conformational change in CFP/YFP-tagged WT-Cav1 pairs. We conclude that phosphorylation of Cav1 leads to separation or “spreading” of neighboring negatively charged N-terminal phosphotyrosine residues, promoting swelling of caveolae, followed by their release from the plasma membrane. PMID:27170175

  15. L-theanine promotes nitric oxide production in endothelial cells through eNOS phosphorylation.

    PubMed

    Siamwala, Jamila H; Dias, Paul M; Majumder, Syamantak; Joshi, Manoj K; Sinkar, Vilas P; Banerjee, Gautam; Chatterjee, Suvro

    2013-03-01

    Consumption of tea (Camellia sinensis) improves vascular function and is linked to lowering the risk of cardiovascular disease. Endothelial nitric oxide is the key regulator of vascular functions in endothelium. In this study, we establish that l-theanine, a non-protein amino-acid found in tea, promotes nitric oxide (NO) production in endothelial cells. l-theanine potentiated NO production in endothelial cells was evaluated using Griess reaction, NO sensitive electrode and a NO specific fluorescent probe (4-amino-5-methylamino-2',7'-difluororescein diacetate). l-Theanine induced NO production was partially attenuated in presence of l-NAME or l-NIO and completely abolished using eNOS siRNA. eNOS activation was Ca(2+) and Akt independent, as assessed by fluo-4AM and immunoblotting experiments, respectively and was associated with phosphorylation of eNOS Ser 1177. eNOS phosphorylation was inhibited in the presence of ERK1/2 inhibitor, PD-98059 and partially inhibited by PI3K inhibitor, LY-294002 and Wortmanin suggesting PI3K-ERK1/2 dependent pathway. Increased NO production was associated with vasodilation in ex ovo (chorioallantoic membrane) model. These results demonstrated that l-theanine administration in vitro activated ERK/eNOS resulting in enhanced NO production and thereby vasodilation in the artery. The results of our experiments are suggestive of l-theanine mediated vascular health benefits of tea.

  16. Rck1 promotes pseudohyphal growth via the activation of Ubp3 phosphorylation in Saccharomyces cerevisiae.

    PubMed

    Kang, Chang-Min; Chang, Miwha; Park, Yong-Sung; Yun, Cheol-Won

    2016-01-15

    Previously, we reported that Rck1 up-regulates Ras2 and pseudohyphal growth of Saccharomyces cerevisiae. Here, we further investigate the involvement of Rck1 in the activation of pseudohyphal growth. Rck1 activated phosphorylation of the deubiquitinase Ubp3 through a direct protein interaction between Rck1 and Ubp3. The N-terminal Bre5 binding region of Ubp3 physically interacted with Rck1, and Ubp3 and Rck1 co-precipitated. Overexpression of UBP3 using a high-copy plasmid resulted in the upregulation of Ras2, and deletion of UBP3 blocked the upregulation of Ras2 by RCK1 overexpression. Treatment with the proteasome inhibitor MG132 resulted in accumulation of Ras2, indicating that Rck1 is involved in Ras2 degradation in a proteasome-dependent manner. Furthermore, deletion of UBP3 blocked the upregulation of FLO11, a flocculin required for pseudohyphal and invasive growth induced by RCK1 overexpression in S. cerevisiae. Taken together, these results demonstrate that Rck1 promotes S. cerevisiae pseudohyphal growth via the activation of Ubp3 phosphorylation. Copyright © 2015 Elsevier Inc. All rights reserved.

  17. Pyruvate Dehydrogenase Kinase 4 Promotes Vascular Calcification via SMAD1/5/8 Phosphorylation

    PubMed Central

    Lee, Sun Joo; Jeong, Ji Yun; Oh, Chang Joo; Park, Sungmi; Kim, Joon-Young; Kim, Han-Jong; Doo Kim, Nam; Choi, Young-Keun; Do, Ji-Yeon; Go, Younghoon; Ha, Chae-Myung; Choi, Je-Yong; Huh, Seung; Ho Jeoung, Nam; Lee, Ki-Up; Choi, Hueng-Sik; Wang, Yu; Park, Keun-Gyu; Harris, Robert A.; Lee, In-Kyu

    2015-01-01

    Vascular calcification, a pathologic response to defective calcium and phosphate homeostasis, is strongly associated with cardiovascular mortality and morbidity. In this study, we have observed that pyruvate dehydrogenase kinase 4 (PDK4) is upregulated and pyruvate dehydrogenase complex phosphorylation is increased in calcifying vascular smooth muscle cells (VSMCs) and in calcified vessels of patients with atherosclerosis, suggesting that PDK4 plays an important role in vascular calcification. Both genetic and pharmacological inhibition of PDK4 ameliorated the calcification in phosphate-treated VSMCs and aortic rings and in vitamin D3-treated mice. PDK4 augmented the osteogenic differentiation of VSMCs by phosphorylating SMAD1/5/8 via direct interaction, which enhances BMP2 signaling. Furthermore, increased expression of PDK4 in phosphate-treated VSMCs induced mitochondrial dysfunction followed by apoptosis. Taken together, our results show that upregulation of PDK4 promotes vascular calcification by increasing osteogenic markers with no adverse effect on bone formation, demonstrating that PDK4 is a therapeutic target for vascular calcification. PMID:26560812

  18. Phosphorylation of Notch1 by Pim kinases promotes oncogenic signaling in breast and prostate cancer cells

    PubMed Central

    Vahtera, Laura; Ylä-Pelto, Jani; Paloniemi, Elina; Imanishi, Susumu Y.; Corthals, Garry; Varjosalo, Markku; Manoharan, Ganesh Babu; Uri, Asko; Lendahl, Urban; Sahlgren, Cecilia; Koskinen, Päivi J.

    2016-01-01

    Tumorigenesis is a multistep process involving co-operation between several deregulated oncoproteins. In this study, we unravel previously unrecognized interactions and crosstalk between Pim kinases and the Notch signaling pathway, with implications for both breast and prostate cancer. We identify Notch1 and Notch3, but not Notch2, as novel Pim substrates and demonstrate that for Notch1, the serine residue 2152 is phosphorylated by all three Pim family kinases. This target site is located in the second nuclear localization sequence (NLS) of the Notch1 intracellular domain (N1ICD), and is shown to be important for both nuclear localization and transcriptional activity of N1ICD. Phosphorylation-dependent stimulation of Notch1 signaling promotes migration of prostate cancer cells, balances glucose metabolism in breast cancer cells, and supports in vivo growth of both types of cancer cells on chick embryo chorioallantoic membranes. Furthermore, Pim-induced growth of orthotopic prostate xenografts in mice is associated with enhanced nuclear Notch1 activity. Finally, simultaneous inhibition of Pim and Notch abrogates the cellular responses more efficiently than individual treatments, opening up new vistas for combinatorial cancer therapy. PMID:27281612

  19. TFIIIB is phosphorylated, disrupted and selectively released from tRNA promoters during mitosis in vivo.

    PubMed

    Fairley, Jennifer A; Scott, Pamela H; White, Robert J

    2003-11-03

    Mitosis involves a generalized repression of gene expression. In the case of RNA polymerase III transcription, this is due to phosphorylation-mediated inactivation of TFIIIB, an essential complex comprising the TATA-binding protein TBP and the TAF subunits Brf1 and Bdp1. In HeLa cells, this repression is mediated by a mitotic kinase other than cdc2-cyclin B and is antagonized by protein phosphatase 2A. Brf1 is hyperphosphorylated in metaphase-arrested cells, but remains associated with promoters in condensed chromosomes, along with TBP. In contrast, Bdp1 is selectively released. Repression can be reversed by raising the concentration of Brf1 or Bdp1. The data support a model in which hyperphosphorylation disrupts TFIIIB during mitosis, compromising its ability to support transcription.

  20. Staging of intrahepatic cholangiocarcinoma

    PubMed Central

    Ronnekleiv-Kelly, Sean M.

    2017-01-01

    Intrahepatic cholangiocarcinoma (ICC) comprises approximately 5−30% of primary liver tumors, however it has been increasing over the last several decades. Up to and including the 6th edition of the American Joint Committee on Cancer/Union for International Cancer Control (AJCC/UICC) edition staging system, ICC was staged the same as hepatocellular carcinoma. In the 7th edition AJCC/UICC manual, the staging system of ICC was revised such that a distinct classification was proposed. Pathologic features for prognosis included vascular invasion, tumor multiplicity, local extension, periductal infiltration and lymph nodal metastasis. Over the last decade, as the incidence of ICC has increased and surgery for this indication has become more common, more data has been published on the prognostic factors associated with long-term survival. PMID:28261593

  1. Pathological aspects of cholangiocarcinoma

    PubMed Central

    Esposito*, I.

    2008-01-01

    Cholangiocarcinoma (CC) arises from the biliary epithelium and in most cases represents adenocarcinoma. Pathomorphological evaluation is of decisive impact for the prognosis and management of CC. Morphological subtyping (histotype; hilar vs peripheral type), TNM classification, lymphatic spread, and resection margin status are of prognostic relevance. Distinction from hepatic metastases may be aided by immunohistology and clinico-pathological correlation. There is convincing evidence of the development of CC via premalignant lesions, especially biliary intraepithelial neoplasia, although further knowledge about the biology and diagnostic definition of these lesions has to be accumulated. Currently, there are no established molecular markers of prognosis or therapeutic target structures to be evaluated at the tissue level. Future progress is needed and expected in novel differential diagnostic and predictive markers, in uniform definition of resection margin status and further understanding of molecular and morphological changes in the development of CC. PMID:18773061

  2. New insights on cholangiocarcinoma

    PubMed Central

    Gatto, Manuela; Alvaro, Domenico

    2010-01-01

    Cholangiocarcinoma (CCA) is a devastating cancer arising from the neoplastic transformation of the biliary epithelium. It is characterized by a progressive increase in incidence and prevalence. The only curative therapy is radical surgery or liver transplantation but, unfortunately, the majority of patients present with advanced stage disease, which is not amenable to surgical therapies. Recently, proposed serum and bile biomarkers could help in the screening and surveillance of categories at risk and in diagnosing CCA at an early stage. The molecular mechanisms triggering neoplastic transformation and growth of biliary epithelium are still undefined, but significant progress has been achieved in the last few years. This review deals with the most recent advances on epidemiology, biology, and clinical management of CCA. PMID:21160821

  3. Pyruvate kinase type M2 promotes tumour cell exosome release via phosphorylating synaptosome-associated protein 23

    PubMed Central

    Wei, Yao; Wang, Dong; Jin, Fangfang; Bian, Zhen; Li, Limin; Liang, Hongwei; Li, Mingzhen; Shi, Lei; Pan, Chaoyun; Zhu, Dihan; Chen, Xi; Hu, Gang; Liu, Yuan; Zhang, Chen-Yu; Zen, Ke

    2017-01-01

    Tumour cells secrete exosomes that are involved in the remodelling of the tumour–stromal environment and promoting malignancy. The mechanisms governing tumour exosome release, however, remain incompletely understood. Here we show that tumour cell exosomes secretion is controlled by pyruvate kinase type M2 (PKM2), which is upregulated and phosphorylated in tumours. During exosome secretion, phosphorylated PKM2 serves as a protein kinase to phosphorylate synaptosome-associated protein 23 (SNAP-23), which in turn enables the formation of the SNARE complex to allow exosomes release. Direct phosphorylation assay and mass spectrometry confirm that PKM2 phosphorylates SNAP-23 at Ser95. Ectopic expression of non-phosphorylated SNAP-23 mutant (Ser95→Ala95) significantly reduces PKM2-mediated exosomes release whereas expression of selective phosphomimetic SNAP-23 mutants (Ser95→Glu95 but not Ser20→Glu20) rescues the impaired exosomes release induced by PKM2 knockdown. Our findings reveal a non-metabolic function of PKM2, an enzyme associated with tumour cell reliance on aerobic glycolysis, in promoting tumour cell exosome release. PMID:28067230

  4. Obesity-Linked Phosphorylation of SIRT1 by Casein Kinase 2 Inhibits Its Nuclear Localization and Promotes Fatty Liver.

    PubMed

    Choi, Sung E; Kwon, Sanghoon; Seok, Sunmi; Xiao, Zhen; Lee, Kwan-Woo; Kang, Yup; Li, Xiaoling; Shinoda, Kosaku; Kajimura, Shingo; Kemper, Byron; Kemper, Jongsook Kim

    2017-08-01

    Sirtuin1 (SIRT1) deacetylase delays and improves many obesity-related diseases, including nonalcoholic fatty liver disease (NAFLD) and diabetes, and has received great attention as a drug target. SIRT1 function is aberrantly low in obesity, so understanding the underlying mechanisms is important for drug development. Here, we show that obesity-linked phosphorylation of SIRT1 inhibits its function and promotes pathological symptoms of NAFLD. In proteomic analysis, Ser-164 was identified as a major serine phosphorylation site in SIRT1 in obese, but not lean, mice, and this phosphorylation was catalyzed by casein kinase 2 (CK2), the levels of which were dramatically elevated in obesity. Mechanistically, phosphorylation of SIRT1 at Ser-164 substantially inhibited its nuclear localization and modestly affected its deacetylase activity. Adenovirus-mediated liver-specific expression of SIRT1 or a phosphor-defective S164A-SIRT1 mutant promoted fatty acid oxidation and ameliorated liver steatosis and glucose intolerance in diet-induced obese mice, but these beneficial effects were not observed in mice expressing a phosphor-mimic S164D-SIRT1 mutant. Remarkably, phosphorylated S164-SIRT1 and CK2 levels were also highly elevated in liver samples of NAFLD patients and correlated with disease severity. Thus, inhibition of phosphorylation of SIRT1 by CK2 may serve as a new therapeutic approach for treatment of NAFLD and other obesity-related diseases. Copyright © 2017 American Society for Microbiology.

  5. Phosphorylation of eIF4E promotes EMT and metastasis via translational control of SNAIL and MMP-3

    PubMed Central

    Robichaud, Nathaniel; del Rincon, Sonia V.; Huor, Bonnie; Alain, Tommy; Petruccelli, Andy; Hearnden, Jaclyn; Goncalves, Christophe; Grotegut, Stefan; Spruck, Charles H.; Furic, Luc; Larsson, Ola; Miller, Wilson H.; Sonenberg, Nahum

    2016-01-01

    The progression of cancers from primary tumors to invasive and metastatic stages accounts for the overwhelming majority of cancer deaths. Understanding the molecular events which promote metastasis is thus critical in the clinic. Translational control is emerging as an important factor in tumorigenesis. The mRNA cap-binding protein eIF4E is an oncoprotein that plays an important role in cancer initiation and progression. eIF4E must be phosphorylated to promote tumor development. However, the role of eIF4E phosphorylation in metastasis is not known. Here, we show that mice in which eIF4E cannot be phosphorylated are resistant to lung metastases in a mammary tumor model, and that cells isolated from these mice exhibit impaired invasion. We also demonstrate that TGFβ induces eIF4E phosphorylation to promote translation of Snail and Mmp-3 mRNAs, and the induction of epithelial-to-mesenchymal transition (EMT). Furthermore, we describe a new model wherein EMT induced by TGFβ requires translational activation via the non-canonical TGFβ signaling branch acting through eIF4E phosphorylation. PMID:24909168

  6. Loss of Axonal Mitochondria Promotes Tau-Mediated Neurodegeneration and Alzheimer's Disease–Related Tau Phosphorylation Via PAR-1

    PubMed Central

    Iijima-Ando, Kanae; Sekiya, Michiko; Suzuki, Emiko; Lu, Bingwei; Iijima, Koichi M.

    2012-01-01

    Abnormal phosphorylation and toxicity of a microtubule-associated protein tau are involved in the pathogenesis of Alzheimer's disease (AD); however, what pathological conditions trigger tau abnormality in AD is not fully understood. A reduction in the number of mitochondria in the axon has been implicated in AD. In this study, we investigated whether and how loss of axonal mitochondria promotes tau phosphorylation and toxicity in vivo. Using transgenic Drosophila expressing human tau, we found that RNAi–mediated knockdown of milton or Miro, an adaptor protein essential for axonal transport of mitochondria, enhanced human tau-induced neurodegeneration. Tau phosphorylation at an AD–related site Ser262 increased with knockdown of milton or Miro; and partitioning defective-1 (PAR-1), the Drosophila homolog of mammalian microtubule affinity-regulating kinase, mediated this increase of tau phosphorylation. Tau phosphorylation at Ser262 has been reported to promote tau detachment from microtubules, and we found that the levels of microtubule-unbound free tau increased by milton knockdown. Blocking tau phosphorylation at Ser262 site by PAR-1 knockdown or by mutating the Ser262 site to unphosphorylatable alanine suppressed the enhancement of tau-induced neurodegeneration caused by milton knockdown. Furthermore, knockdown of milton or Miro increased the levels of active PAR-1. These results suggest that an increase in tau phosphorylation at Ser262 through PAR-1 contributes to tau-mediated neurodegeneration under a pathological condition in which axonal mitochondria is depleted. Intriguingly, we found that knockdown of milton or Miro alone caused late-onset neurodegeneration in the fly brain, and this neurodegeneration could be suppressed by knockdown of Drosophila tau or PAR-1. Our results suggest that loss of axonal mitochondria may play an important role in tau phosphorylation and toxicity in the pathogenesis of AD. PMID:22952452

  7. MiR-21 promotes intrahepatic cholangiocarcinoma proliferation and growth in vitro and in vivo by targeting PTPN14 and PTEN

    PubMed Central

    Wang, Li-Juan; He, Chen-Chen; Sui, Xin; Cai, Meng-Jiao; Zhou, Cong-Ya; Ma, Jin-Lu; Wu, Lei; Wang, Hao; Han, Su-Xia; Zhu, Qing

    2015-01-01

    Intrahepatic cholangiocarcinoma (ICC) constitutes the second-most common primary hepatic malignancy. MicroRNAs (miRNAs) play important roles in the pathogenesis of ICC. However, the clinical significance of miR-21 levels in ICC remains unclear. Here, we investigated the role of miR-21 in ICC and found that its expression was significantly upregulated in serum of ICC patients. Serum miR-21 levels robustly distinguished ICC patients from control subjects. Further experiments showed that inhibition of miR-21 suppressed ICC cell proliferation in vitro and tumor growth in vivo. Specifically, inhibition of miR-21 induced cell cycle arrest and apoptosis. Moreover, PTPN14 and PTEN were identified as direct and functional targets of miR-21. Finally, we showed high expression levels of miR-21 were closely related to adverse clinical features, diminished survival, and poor prognosis in ICC patients. This study revealed functional and mechanistic links between miR-21 and tumor suppressor genes, PTPN14 and PTEN, in the pathogenesis of ICC. MiR-21 not only plays important roles in the regulation of cell proliferation and tumor growth in ICC, but is also a diagnostic and prognostic marker, and a potential therapeutic target for ICC. PMID:25803229

  8. Antitumor effect of the novel sphingosine kinase 2 inhibitor ABC294640 is enhanced by inhibition of autophagy and by sorafenib in human cholangiocarcinoma cells

    PubMed Central

    Ding, Xiwei; Chaiteerakij, Roongruedee; Moser, Catherine D.; Shaleh, Hassan; Boakye, Jeffrey; Chen, Gang; Ndzengue, Albert; Li, Ying; Zhou, Yanling; Huang, Shengbing; Sinicrope, Frank A.; Zou, Xiaoping; Thomas, Melanie B.; Smith, Charles D.; Roberts, Lewis R.

    2016-01-01

    Sphingosine kinase 2 (Sphk2) has an oncogenic role in cancer. A recently developed first-in-class Sphk2 specific inhibitor ABC294640 displays antitumor activity in many cancer models. However, the role of Sphk2 and the antitumor activity of its inhibitor ABC294640 are not known in cholangiocarcinoma. We investigated the potential of targeting Sphk2 for the treatment of cholangiocarcinoma. We found that Sphk2 is overexpressed in five established human cholangiocarcinoma cell lines (WITT, HuCCT1, EGI-1, OZ and HuH28) and a new patient-derived cholangiocarcinoma cell line (LIV27) compared to H69 normal cholangiocytes. Inhibition of Sphk2 by ABC294640 inhibited proliferation and induced caspase-dependent apoptosis. Furthermore, we found that ABC294640 inhibited STAT3 phosphorylation, one of the key signaling pathways regulating cholangiocarcinoma cell proliferation and survival. ABC294640 also induced autophagy. Inhibition of autophagy by bafilomycin A1 or chloroquine potentiated ABC294640-induced cytotoxicity and apoptosis. In addition, ABC294640 in combination with sorafenib synergistically inhibited cell proliferation of cholangiocarcinoma cells. Strong decreases in STAT3 phosphorylation were observed in WITT and HuCCT1 cells exposed to the ABC294640 and sorafenib combination. These findings provide novel evidence that Sphk2 may be a rational therapeutic target in cholangiocarcinoma. Combinations of ABC294640 with sorafenib and/or autophagy inhibitors may provide novel strategies for the treatment of cholangiocarcinoma. PMID:26956050

  9. 5-HT7 receptor activation promotes an increase in TrkB receptor expression and phosphorylation

    PubMed Central

    Samarajeewa, Anshula; Goldemann, Lolita; Vasefi, Maryam S.; Ahmed, Nawaz; Gondora, Nyasha; Khanderia, Chandni; Mielke, John G.; Beazely, Michael A.

    2014-01-01

    The serotonin (5-HT) type 7 receptor is expressed throughout the CNS including the cortex and hippocampus. We have previously demonstrated that the application of 5-HT7 receptor agonists to primary hippocampal neurons and SH-SY5Y cells increases platelet-derived growth factor (PDGF) receptor expression and promotes neuroprotection against N-methyl-D-aspartate-(NMDA)-induced toxicity. The tropomyosin-related kinase B (TrkB) receptor is one of the receptors for brain-derived neurotrophic factor (BDNF) and is associated with neurodevelopmental and neuroprotective effects. Application of LP 12 to primary cerebral cortical cultures, SH-SY5Y cells, as well as the retinal ganglion cell line, RGC-5, increased both the expression of full length TrkB as well as its basal phosphorylation state at tyrosine 816. The increase in TrkB expression and phosphorylation was observed as early as 30 min after 5-HT7 receptor activation. In addition to full-length TrkB, kinase domain-deficient forms may be expressed and act as dominant-negative proteins toward the full length receptor. We have identified distinct patterns of TrkB isoform expression across our cell lines and cortical cultures. Although TrkB receptor expression is regulated by cyclic AMP and Gαs-coupled GPCRs in several systems, we demonstrate that, depending on the model system, pathways downstream of both Gαs and Gα12 are involved in the regulation of TrkB expression by 5-HT7 receptors. Given the number of psychiatric and degenerative diseases associated with TrkB/BDNF deficiency and the current interest in developing 5-HT7 receptor ligands as pharmaceuticals, identifying signaling relationships between these two receptors will aid in our understanding of the potential therapeutic effects of 5-HT7 receptor ligands. PMID:25426041

  10. 5-HT7 receptor activation promotes an increase in TrkB receptor expression and phosphorylation.

    PubMed

    Samarajeewa, Anshula; Goldemann, Lolita; Vasefi, Maryam S; Ahmed, Nawaz; Gondora, Nyasha; Khanderia, Chandni; Mielke, John G; Beazely, Michael A

    2014-01-01

    The serotonin (5-HT) type 7 receptor is expressed throughout the CNS including the cortex and hippocampus. We have previously demonstrated that the application of 5-HT7 receptor agonists to primary hippocampal neurons and SH-SY5Y cells increases platelet-derived growth factor (PDGF) receptor expression and promotes neuroprotection against N-methyl-D-aspartate-(NMDA)-induced toxicity. The tropomyosin-related kinase B (TrkB) receptor is one of the receptors for brain-derived neurotrophic factor (BDNF) and is associated with neurodevelopmental and neuroprotective effects. Application of LP 12 to primary cerebral cortical cultures, SH-SY5Y cells, as well as the retinal ganglion cell line, RGC-5, increased both the expression of full length TrkB as well as its basal phosphorylation state at tyrosine 816. The increase in TrkB expression and phosphorylation was observed as early as 30 min after 5-HT7 receptor activation. In addition to full-length TrkB, kinase domain-deficient forms may be expressed and act as dominant-negative proteins toward the full length receptor. We have identified distinct patterns of TrkB isoform expression across our cell lines and cortical cultures. Although TrkB receptor expression is regulated by cyclic AMP and Gαs-coupled GPCRs in several systems, we demonstrate that, depending on the model system, pathways downstream of both Gαs and Gα12 are involved in the regulation of TrkB expression by 5-HT7 receptors. Given the number of psychiatric and degenerative diseases associated with TrkB/BDNF deficiency and the current interest in developing 5-HT7 receptor ligands as pharmaceuticals, identifying signaling relationships between these two receptors will aid in our understanding of the potential therapeutic effects of 5-HT7 receptor ligands.

  11. A DNA break– and phosphorylation-dependent positive feedback loop promotes immunoglobulin class-switch recombination

    PubMed Central

    Vuong, Bao Q; Ucher, Anna J; Donghia, Nina M; Gu, Xiwen; Nicolas, Laura; Nowak, Urszula; Rahman, Numa; Strout, Matthew P; Mills, Kevin D; Stavnezer, Janet; Chaudhuri, Jayanta

    2014-01-01

    The ability of activation-induced cytidine deaminase (AID) to efficiently mediate class-switch recombination (CSR) is dependent on its phosphorylation at Ser38; however, the trigger that induces AID phosphorylation and the mechanism by which phosphorylated AID drives CSR have not been elucidated. Here we found that phosphorylation of AID at Ser38 was induced by DNA breaks. Conversely, in the absence of AID phosphorylation, DNA breaks were not efficiently generated at switch (S) regions in the immunoglobulin heavy-chain locus (Igh), consistent with a failure of AID to interact with the endonuclease APE1. Additionally, deficiency in the DNA-damage sensor ATM impaired the phosphorylation of AID at Ser38 and the interaction of AID with APE1. Our results identify a positive feedback loop for the amplification of DNA breaks at S regions through the phosphorylation- and ATM-dependent interaction of AID with APE1. PMID:24097111

  12. Locoregional Therapies of Cholangiocarcinoma.

    PubMed

    Sommer, Christof M; Kauczor, Hans U; Pereira, Philippe L

    2016-12-01

    Cholangiocarcinoma (CC) is the second most primary liver malignancy with increasing incidence in Western countries. Currently, surgical R0 resection is regarded as the only potentially curative treatment. The results of systemic chemotherapy and best supportive care (BSC) in patients with metastatic disease are often disappointing in regard to toxicity, oncologic efficacy, and overall survival. In current practice, the use of different locoregional therapies is increasingly more accepted. A review of the literature on locoregional therapies for intrahepatic cholangiocarcinoma (ICC) was undertaken. There are no prospective randomized controlled trials. For localized ICC, either primary or recurrent, radiofrequency ablation (RFA) is by far the most commonly used thermal ablation modality. Thereby, a systematic review and meta-analysis reports major complication in 3.8% as well as 1-, 3-, and 5-year overall survival rates of 82, 47, and 24%, respectively. In selected patients (e.g. with a tumor diameter of ≤3 cm), oncologic efficacy and survival after RFA are comparable with surgical resection. For diffuse ICC, different transarterial therapies, either chemotherapy-based (hepatic artery infusion (HAI), transarterial chemoembolization (TACE)) or radiotherapy-based (transarterial radioembolization (TARE)), show extremely promising results. With regard to controlled trials (transarterial therapy versus systemic chemotherapy, BSC or no treatment), tumor control is virtually always better for transarterial therapies and very often accompanied by a dramatic survival benefit and improvement of quality of life. Of note, the latter is the case not only for patients without extrahepatic metastatic disease but also for those with liver-dominant extrahepatic metastatic disease. There are other locoregional therapies such as microwave ablation, irreversible electroporation, and chemosaturation; however, the current data support their use only in controlled trials or as last

  13. Phosphorylation of TRPV1 by cyclin-dependent kinase 5 promotes TRPV1 surface localization, leading to inflammatory thermal hyperalgesia.

    PubMed

    Liu, Jiao; Du, Junxie; Yang, Yanrui; Wang, Yun

    2015-11-01

    Cyclin-dependent kinase 5 (Cdk5) is an important serine/threonine kinase that plays critical roles in many physiological processes. Recently, Cdk5 has been reported to phosphorylate TRPV1 at threonine 407 (Thr-407) in humans (Thr-406 in rats), which enhances the function of TRPV1 channel and promotes thermal hyperalgesia in the complete Freund's adjuvant (CFA)-induced inflammatory pain rats. However, the underlying mechanisms are still unknown. Here, we demonstrate that Cdk5 phosphorylates TRPV1 at Threonine 406 and promotes the surface localization of TRPV1, leading to inflammatory thermal hyperalgesia. The mutation of Thr-406 of TRPV1 to alanine reduced the interaction of TRPV1 with the cytoskeletal elements and decreased the binding of TRPV1 with the motor protein KIF13B, which led to reduced surface distribution of TRPV1. Disrupting the phosphorylation of TRPV1 at Thr-406 dramatically reduced the surface level of TRPV1 in HEK 293 cells after transient expression and the channel function in cultured dorsal root ganglion (DRG) neurons. Notably, intrathecal administration of the interfering peptide against the phosphorylation of Thr-406 alleviated heat hyperalgesia and reduced the surface level of TRPV1 in inflammatory pain rats. Together, these results demonstrate that Cdk5-mediated phosphorylation of TRPV1 at Thr-406 increases the surface level and the function of TRPV1, while the TAT-T406 peptide can effectively attenuate thermal hyperalgesia. Our studies provide a potential therapy for inflammatory pain.

  14. Structured DNA promotes phosphorylation of p53 by DNA-dependent protein kinase at serine 9 and threonine 18.

    PubMed

    Soubeyrand, Sébastien; Schild-Poulter, Caroline; Haché, Robert J G

    2004-09-01

    Phosphorylation at multiple sites within the N-terminus of p53 promotes its dissociation from hdm2/mdm2 and stimulates its transcriptional regulatory potential. The large phosphoinositide 3-kinase-like kinases ataxia telangiectasia mutated gene product and the ataxia telangectasia and RAD-3-related kinase promote phosphorylation of human p53 at Ser15 and Ser20, and are required for the activation of p53 following DNA damage. DNA-dependent protein kinase (DNA-PK) is another large phosphoinositide 3-kinase-like kinase with the potential to phosphorylate p53 at Ser15, and has been proposed to enhance phosphorylation of these sites in vivo. Moreover, recent studies support a role for DNA-PK in the regulation of p53-mediated apoptosis. We have shown previously that colocalization of p53 and DNA-PK to structured single-stranded DNA dramatically enhances the potential for p53 phosphorylation by DNA-PK. We report here the identification of p53 phosphorylation at two novel sites for DNA-PK, Thr18 and Ser9. Colocalization of p53 and DNA-PK on structured DNA was required for efficient phosphorylation of p53 at multiple sites, while specific recognition of Ser9 and Thr18 appeared to be dependent upon additional determinants of p53 beyond the N-terminal 65 amino acids. Our results suggest a role for DNA-PK in the modulation of p53 activity resultant from the convergence of p53 and DNA-PK on structured DNA.

  15. Promotion of PDGF-induced endothelial cell migration by phosphorylated VASP depends on PKA anchoring via AKAP.

    PubMed

    Zhang, Deling; Ouyang, Jingping; Wang, Nian; Zhang, Yahui; Bie, Jinghua; Zhang, Yemin

    2010-02-01

    Vasodilator-stimulated phosphoprotein (VASP), an important substrate of PKA, plays a critical role in remodeling of actin cytoskeleton and actin-based cell motility. However, how PKA accurately transfers extracellular signals to VASP and then how phosphorylation of VASP regulates endothelial cell migration have not been clearly defined. Protein kinase A anchoring proteins (AKAPs) are considered to regulate intracellular-specific signal targeting of PKA via AKAP-mediated PKA anchoring. Thus, our study investigated the relationship among AKAP anchoring of PKA, PKA activity, and VASP phosphorylation, which is to clarify the exact role of VASP and its upstream regulatory mechanism in PKA-dependent migration. Our results show that chemotactic factor PDGF activated PKA, increased phosphorylation of VASP at Ser157, and enhanced ECV304 endothelial cell migration. However, phosphorylation site-directed mutation of VASP at Ser157 attenuated the chemotactic effect of PDGF on endothelial cells, suggesting phosphorylation of VASP at Ser157 promotes PKA-mediated endothelial cell migration. Furthermore, disrupting PKA anchoring to AKAP or PKA activity significantly attenuated the PKA activity, VASP phosphorylation, and subsequent cell migration. Meanwhile, disrupting PKA anchoring to AKAP abolished PDGF-induced lamellipodia formation and special VASP accumulation at leading edge of lamellipodia. These results indicate that PKA activation and PKA-mediated substrate responses in VASP phosphorylation and localization depend on PKA anchoring via AKAP in PDGF-induced endothelial cell migration. In conclusion, AKAP anchoring of PKA is an essential upstream event in regulation of PKA-mediated VASP phosphorylation and subsequent endothelial cell migration, which contributes to explore new methods for controlling endothelial cell migration related diseases and angiogenesis.

  16. Agonist-promoted desensitization and phosphorylation of. cap alpha. /sub 1/-adrenergic receptors coupled to stimulation of phosphatidylinositol metabolism

    SciTech Connect

    Leeb-Lundberg, L.M.F.; Cotecchia, S.; Caron, M.G.; Lefkowitz, R.J.

    1986-03-05

    In the DDT/sub 1/ MF-2 hamster vas deferens smooth muscle cell line the ..cap alpha../sub 1/-adrenergic receptor (..cap alpha../sub 1/-AR) agonist norepinephrine (NE) promotes rapid attenuation of ..cap alpha../sub 1/-AR-mediated phosphatidylinositol (PI) metabolism which is paralleled by rapid phosphorylation of the ..cap alpha../sub 1/-AR. Cells were labeled by incubation with /sup 32/P/sub i/. Coincubation with NE (100 ..mu..M) significantly increases the rate of /sup 32/P-labeling of both PI and phosphatidic acid. Pretreatment of cells with 100 ..mu..M NE (in the presence of 1 ..mu..M propranolol to prevent ..beta..-AR interactions) results in a drastic attenuation of the NE response on PI metabolism. ..cap alpha../sub 1/-AR from labeled cells can be solubilized and purified by affinity chromatography on Affigel-A55414 and wheat germ agglutinin agarose chromatography. SDS-PAGE of purified ..cap alpha../sub 1/-AR shows a NE-promoted increase in phosphorylation of the M/sub r/ 80K ligand binding peptide. Stoichiometry of phosphorylation increases from approx. 1 mol phosphate/mol ..cap alpha../sub 1/-AR in the basal condition to approx. 2.5 after NE treatment. Both desensitization and phosphorylation are rapid being maximal within 10-20 min of agonist exposure. These results together with previous findings that phorbol esters promote rapid ..cap alpha../sub 1/-AR uncoupling and phosphorylation suggest that receptor phosphorylation is an important mechanism of regulation of ..cap alpha../sub 1/-AR receptor responsiveness.

  17. Pathology of intrahepatic cholangiocarcinoma

    PubMed Central

    Vijgen, Sandrine; Terris, Benoit

    2017-01-01

    Intrahepatic cholangiocarcinoma (iCC) is a primary carcinoma of the liver with increasing significance and major pathogenic, clinical and therapeutic challenges. Classically, it arises from malignant transformation of cholangiocytes bordering small portal bile duct (BD) to second-order segmental large BDs. It has three major macroscopic growth pattern [mass-forming (MF), periductal infiltrative (PI), and intraductal growth (IG)] and histologically is a desmoplastic stroma-rich adenocarcinoma with cholangiocyte differentiation. Recent data pointed out noteworthy degree of heterogeneity in regards of their epidemiology and risk factors, pathological and molecular features, pathogenesis, clinical behaviors and treatment. Notably, several histological variants are described and can coexist within the same tumor. Several different cells of origin have also been depicted in a fraction of iCCs, amongst which malignant transformation of ductules, of hepatic stem/progenitor cells, of periductal glands or through oncogenic reprogramming of adult hepatocytes. A degree of pathological overlap with hepatocellular carcinoma (HCC) may be observed in a portion of iCC. A series of precursor lesions are today characterized and emphasize the existence of a multistep carcinogenesis process. Overall, these new data have brought up in proposal of new histological or molecular classifications, which could soon replace current anatomic-based classification and could have major impact on establishment of prognosis and on development of novel target treatment approaches. PMID:28261592

  18. IKKβ promotes metabolic adaptation to glutamine deprivation via phosphorylation and inhibition of PFKFB3.

    PubMed

    Reid, Michael A; Lowman, Xazmin H; Pan, Min; Tran, Thai Q; Warmoes, Marc O; Ishak Gabra, Mari B; Yang, Ying; Locasale, Jason W; Kong, Mei

    2016-08-15

    Glutamine is an essential nutrient for cancer cell survival and proliferation. Enhanced utilization of glutamine often depletes its local supply, yet how cancer cells adapt to low glutamine conditions is largely unknown. Here, we report that IκB kinase β (IKKβ) is activated upon glutamine deprivation and is required for cell survival independently of NF-κB transcription. We demonstrate that IKKβ directly interacts with and phosphorylates 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase isoform 3 (PFKFB3), a major driver of aerobic glycolysis, at Ser269 upon glutamine deprivation to inhibit its activity, thereby down-regulating aerobic glycolysis when glutamine levels are low. Thus, due to lack of inhibition of PFKFB3, IKKβ-deficient cells exhibit elevated aerobic glycolysis and lactate production, leading to less glucose carbons contributing to tricarboxylic acid (TCA) cycle intermediates and the pentose phosphate pathway, which results in increased glutamine dependence for both TCA cycle intermediates and reactive oxygen species suppression. Therefore, coinhibition of IKKβ and glutamine metabolism results in dramatic synergistic killing of cancer cells both in vitro and in vivo. In all, our results uncover a previously unidentified role of IKKβ in regulating glycolysis, sensing low-glutamine-induced metabolic stress, and promoting cellular adaptation to nutrient availability. © 2016 Reid et al.; Published by Cold Spring Harbor Laboratory Press.

  19. IKKβ promotes metabolic adaptation to glutamine deprivation via phosphorylation and inhibition of PFKFB3

    PubMed Central

    Reid, Michael A.; Lowman, Xazmin H.; Pan, Min; Tran, Thai Q.; Warmoes, Marc O.; Ishak Gabra, Mari B.; Yang, Ying; Locasale, Jason W.; Kong, Mei

    2016-01-01

    Glutamine is an essential nutrient for cancer cell survival and proliferation. Enhanced utilization of glutamine often depletes its local supply, yet how cancer cells adapt to low glutamine conditions is largely unknown. Here, we report that IκB kinase β (IKKβ) is activated upon glutamine deprivation and is required for cell survival independently of NF-κB transcription. We demonstrate that IKKβ directly interacts with and phosphorylates 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase isoform 3 (PFKFB3), a major driver of aerobic glycolysis, at Ser269 upon glutamine deprivation to inhibit its activity, thereby down-regulating aerobic glycolysis when glutamine levels are low. Thus, due to lack of inhibition of PFKFB3, IKKβ-deficient cells exhibit elevated aerobic glycolysis and lactate production, leading to less glucose carbons contributing to tricarboxylic acid (TCA) cycle intermediates and the pentose phosphate pathway, which results in increased glutamine dependence for both TCA cycle intermediates and reactive oxygen species suppression. Therefore, coinhibition of IKKβ and glutamine metabolism results in dramatic synergistic killing of cancer cells both in vitro and in vivo. In all, our results uncover a previously unidentified role of IKKβ in regulating glycolysis, sensing low-glutamine-induced metabolic stress, and promoting cellular adaptation to nutrient availability. PMID:27585591

  20. Retinoblastoma protein promotes oxidative phosphorylation through upregulation of glycolytic genes in oncogene-induced senescent cells.

    PubMed

    Takebayashi, Shin-Ichiro; Tanaka, Hiroshi; Hino, Shinjiro; Nakatsu, Yuko; Igata, Tomoka; Sakamoto, Akihisa; Narita, Masashi; Nakao, Mitsuyoshi

    2015-08-01

    Metabolism is closely linked with cellular state and biological processes, but the mechanisms controlling metabolic properties in different contexts remain unclear. Cellular senescence is an irreversible growth arrest induced by various stresses, which exhibits active secretory and metabolic phenotypes. Here, we show that retinoblastoma protein (RB) plays a critical role in promoting the metabolic flow by activating both glycolysis and mitochondrial oxidative phosphorylation (OXPHOS) in cells that have undergone oncogene-induced senescence (OIS). A combination of real-time metabolic monitoring, and metabolome and gene expression analyses showed that OIS-induced fibroblasts developed an accelerated metabolic flow. The loss of RB downregulated a series of glycolytic genes and simultaneously reduced metabolites produced from the glycolytic pathway, indicating that RB upregulates glycolytic genes in OIS cells. Importantly, both mitochondrial OXPHOS and glycolytic activities were abolished in RB-depleted or downstream glycolytic enzyme-depleted OIS cells, suggesting that RB-mediated glycolytic activation induces a metabolic flux into the OXPHOS pathway. Collectively, our findings reveal that RB essentially functions in metabolic remodeling and the maintenance of the active energy production in OIS cells.

  1. Retinoblastoma protein promotes oxidative phosphorylation through upregulation of glycolytic genes in oncogene-induced senescent cells

    PubMed Central

    Takebayashi, Shin-ichiro; Tanaka, Hiroshi; Hino, Shinjiro; Nakatsu, Yuko; Igata, Tomoka; Sakamoto, Akihisa; Narita, Masashi; Nakao, Mitsuyoshi

    2015-01-01

    Metabolism is closely linked with cellular state and biological processes, but the mechanisms controlling metabolic properties in different contexts remain unclear. Cellular senescence is an irreversible growth arrest induced by various stresses, which exhibits active secretory and metabolic phenotypes. Here, we show that retinoblastoma protein (RB) plays a critical role in promoting the metabolic flow by activating both glycolysis and mitochondrial oxidative phosphorylation (OXPHOS) in cells that have undergone oncogene-induced senescence (OIS). A combination of real-time metabolic monitoring, and metabolome and gene expression analyses showed that OIS-induced fibroblasts developed an accelerated metabolic flow. The loss of RB downregulated a series of glycolytic genes and simultaneously reduced metabolites produced from the glycolytic pathway, indicating that RB upregulates glycolytic genes in OIS cells. Importantly, both mitochondrial OXPHOS and glycolytic activities were abolished in RB-depleted or downstream glycolytic enzyme-depleted OIS cells, suggesting that RB-mediated glycolytic activation induces a metabolic flux into the OXPHOS pathway. Collectively, our findings reveal that RB essentially functions in metabolic remodeling and the maintenance of the active energy production in OIS cells. PMID:26009982

  2. Chemotherapy for cholangiocarcinoma: An update.

    PubMed

    Ramírez-Merino, Natalia; Aix, Santiago Ponce; Cortés-Funes, Hernán

    2013-07-15

    Cholangiocarcinomas (bile duct cancers) are a heterogeneous group of malignancies arising from the epithelial cells of the intrahepatic, perihilar and extrahepatic bile ducts. Patients diagnosed with cholangiocarcinoma must be evaluated by a multidisciplinary team and be treated with individualized management. First of all, it is very important to define the potential resectability of the tumor because surgery is the main therapeutic option for these patients. Overall, cholangiocarcinomas have a very poor prognosis. The 5-year survival rate is 5%-10%. In cases with a potentially curative surgery, 5-year survival rates of 25%-30% are reported. Therefore, it is necessary to increase the cure rate from surgery, exploring the survival benefit of any adjuvant strategy. It is difficult to clarify the role of adjuvant treatment in localized and locally advanced cholangiocarcinomas. There are limited data and the role of adjuvant chemotherapy/chemoradiation in patients with resected biliary tract cancer is poorly defined. The most relevant studies in the adjuvant setting are one from Japan, the well known ESPAC-3 and BILCAP from the United Kingdom and a meta-analysis. We show the results of these trials. According to medical oncology guidelines, postoperative adjuvant therapy is widely recommended for all patients with intrahepatic or extrahepatic cholangiocarcinoma who have microscopically positive resection margins, as well as for those with a complete resection but node-positive disease. Clinical trials are ongoing. The locally advanced cholangiocarcinoma setting includes a heterogeneous mix of patients: (1) patients who have had surgery but with macroscopic residual disease; (2) patients with locally recurrent disease after potentially curative treatment; and (3) patients with locally unresectable disease at presentation. In these patients, surgery is not an option and chemoradiation therapy can prolong overall survival and provide control of symptoms due to local

  3. Chemotherapy for cholangiocarcinoma: An update

    PubMed Central

    Ramírez-Merino, Natalia; Aix, Santiago Ponce; Cortés-Funes, Hernán

    2013-01-01

    Cholangiocarcinomas (bile duct cancers) are a heterogeneous group of malignancies arising from the epithelial cells of the intrahepatic, perihilar and extrahepatic bile ducts. Patients diagnosed with cholangiocarcinoma must be evaluated by a multidisciplinary team and be treated with individualized management. First of all, it is very important to define the potential resectability of the tumor because surgery is the main therapeutic option for these patients. Overall, cholangiocarcinomas have a very poor prognosis. The 5-year survival rate is 5%-10%. In cases with a potentially curative surgery, 5-year survival rates of 25%-30% are reported. Therefore, it is necessary to increase the cure rate from surgery, exploring the survival benefit of any adjuvant strategy. It is difficult to clarify the role of adjuvant treatment in localized and locally advanced cholangiocarcinomas. There are limited data and the role of adjuvant chemotherapy/chemoradiation in patients with resected biliary tract cancer is poorly defined. The most relevant studies in the adjuvant setting are one from Japan, the well known ESPAC-3 and BILCAP from the United Kingdom and a meta-analysis. We show the results of these trials. According to medical oncology guidelines, postoperative adjuvant therapy is widely recommended for all patients with intrahepatic or extrahepatic cholangiocarcinoma who have microscopically positive resection margins, as well as for those with a complete resection but node-positive disease. Clinical trials are ongoing. The locally advanced cholangiocarcinoma setting includes a heterogeneous mix of patients: (1) patients who have had surgery but with macroscopic residual disease; (2) patients with locally recurrent disease after potentially curative treatment; and (3) patients with locally unresectable disease at presentation. In these patients, surgery is not an option and chemoradiation therapy can prolong overall survival and provide control of symptoms due to local

  4. ABT737 enhances cholangiocarcinoma sensitivity to cisplatin through regulation of mitochondrial dynamics

    SciTech Connect

    Fan, Zhongqi; Yu, Huimei; Cui, Ni; Kong, Xianggui; Liu, Xiaomin; Chang, Yulei; Wu, Yao; Sun, Liankun; Wang, Guangyi

    2015-07-01

    Cholangiocarcinoma responses weakly to cisplatin. Mitochondrial dynamics participate in the response to various stresses, and mainly involve mitophagy and mitochondrial fusion and fission. Bcl-2 family proteins play critical roles in orchestrating mitochondrial dynamics, and are involved in the resistance to cisplatin. Here we reported that ABT737, combined with cisplatin, can promote cholangiocarcinoma cells to undergo apoptosis. We found that the combined treatment decreased the Mcl-1 pro-survival form and increased Bak. Cells undergoing cisplatin treatment showed hyperfused mitochondria, whereas fragmentation was dominant in the mitochondria of cells exposed to the combined treatment, with higher Fis1 levels, decreased Mfn2 and OPA1 levels, increased ratio of Drp1 60 kD to 80 kD form, and more Drp1 located on mitochondria. More p62 aggregates were observed in cells with fragmented mitochondria, and they gradually translocated to mitochondria. Mitophagy was induced by the combined treatment. Knockdown p62 decreased the Drp1 ratio, increased Tom20, and increased cell viability. Our data indicated that mitochondrial dynamics play an important role in the response of cholangiocarcinoma to cisplatin. ABT737 might enhance cholangiocarcinoma sensitivity to cisplatin through regulation of mitochondrial dynamics and the balance within Bcl-2 family proteins. Furthermore, p62 seems to be critical in the regulation of mitochondrial dynamics. - Highlights: • Cholangiocarcinoma may adapt to cisplatin through mitochondrial fusion. • ABT737 sensitizes cholangiocarcinoma to cisplatin by promoting fission and mitophagy. • p62 might participate in the regulation of mitochondrial fission and mitophagy.

  5. Phosphorylation of the tumor suppressor CYLD by the breast cancer oncogene IKKε promotes cell transformation

    PubMed Central

    Hutti, Jessica E.; Shen, Rhine R.; Abbott, Derek W.; Zhou, Alicia Y.; Sprott, Kam M.; Asara, John M.; Hahn, William C.; Cantley, Lewis C.

    2009-01-01

    Summary The non-canonical IKK family member IKKε is essential for regulating anti-viral signaling pathways and is a recently-discovered breast cancer oncoprotein. Although several IKKε targets have been described, direct IKKε substrates necessary for regulating cell transformation have not been identified. Here, we performed a screen for putative IKKε substrates using an unbiased proteomic and bioinformatic approach. Using a positional scanning peptide library assay we determined the optimal phosphorylation motif for IKKε and used bioinformatic approaches to predict IKKε substrates. Of these potential substrates, serine 418 of the tumor suppressor CYLD was identified as a likely site of IKKε phosphorylation. We confirmed that CYLD is directly phosphorylated by IKKε, and that IKKε phosphorylates serine 418 in vivo. Phosphorylation of CYLD at serine 418 decreases its deubiquitinase activity and is necessary for IKKε-driven transformation. Together, these observations define IKKε and CYLD as an oncogene-tumor suppressor network that participates in tumorigenesis. PMID:19481526

  6. Phosphorylation of OPTN by TBK1 enhances its binding to Ub chains and promotes selective autophagy of damaged mitochondria

    PubMed Central

    Richter, Benjamin; Sliter, Danielle A.; Herhaus, Lina; Stolz, Alexandra; Wang, Chunxin; Beli, Petra; Zaffagnini, Gabriele; Wild, Philipp; Martens, Sascha; Wagner, Sebastian A.; Youle, Richard J.; Dikic, Ivan

    2016-01-01

    Selective autophagy of damaged mitochondria requires autophagy receptors optineurin (OPTN), NDP52 (CALCOCO2), TAX1BP1, and p62 (SQSTM1) linking ubiquitinated cargo to autophagic membranes. By using quantitative proteomics, we show that Tank-binding kinase 1 (TBK1) phosphorylates all four receptors on several autophagy-relevant sites, including the ubiquitin- and LC3-binding domains of OPTN and p62/SQSTM1 as well as the SKICH domains of NDP52 and TAX1BP1. Constitutive interaction of TBK1 with OPTN and the ability of OPTN to bind to ubiquitin chains are essential for TBK1 recruitment and kinase activation on mitochondria. TBK1 in turn phosphorylates OPTN’s UBAN domain at S473, thereby expanding the binding capacity of OPTN to diverse Ub chains. In combination with phosphorylation of S177 and S513, this posttranslational modification promotes recruitment and retention of OPTN/TBK1 on ubiquitinated, damaged mitochondria. Moreover, phosphorylation of OPTN on S473 enables binding to pS65 Ub chains and is also implicated in PINK1-driven and Parkin-independent mitophagy. Thus, TBK1-mediated phosphorylation of autophagy receptors creates a signal amplification loop operating in selective autophagy of damaged mitochondria. PMID:27035970

  7. Metabolic preconditioning of mammalian cells: mimetic agents for hypoxia lack fidelity in promoting phosphorylation of pyruvate dehydrogenase.

    PubMed

    Borcar, Apurva; Menze, Michael A; Toner, Mehmet; Hand, Steven C

    2013-01-01

    Induction of HIF-1α by oxygen limitation promotes increased phosphorylation and catalytic depression of mitochondrial pyruvate dehydrogenase (PDH) and an enhanced glycolytic poise in cells. Cobalt chloride and desferrioxamine are widely used as mimics for hypoxia because they increase the levels of HIF-1α. We evaluated the ability of these agents to elicit selected physiological responses to hypoxia as a means to metabolically precondition mammalian cells, but without the detrimental effects of hypoxia. We show that, while CoCl(2) does increase HIF-1α in a dose-dependent manner, it unexpectedly and strikingly decreases PDH phosphorylation at E1α sites 1, 2, and 3 (Ser(293), Ser(300), and Ser(232), respectively) in HepG2 cells. This same effect is also observed for site 1 in mouse NIH/3T3 fibroblasts and J774 macrophages. CoCl(2) unexpectedly decreases the mRNA expression for PDH kinase-2 in HepG2 cells, which likely explains the dephosphorylation of PDH observed. And nor does desferrioxamine promote the expected increase in PDH phosphorylation. Dimethyloxaloylglycine (a prolyl hydroxylase inhibitor) performs better in this regard, but failed to promote the stronger effects seen with hypoxia. Consequently, CoCl(2) and desferrioxamine are unreliable mimics of hypoxia for physiological events downstream of HIF-1α stabilization. Our study demonstrates that mimetic chemicals must be chosen with caution and evaluated thoroughly if bona fide cellular outcomes are to be promoted with fidelity.

  8. Palliation: Hilar cholangiocarcinoma

    PubMed Central

    Goenka, Mahesh Kr; Goenka, Usha

    2014-01-01

    Hilar cholangiocarcinomas are common tumors of the bile duct that are often unresectable at presentation. Palliation, therefore, remains the goal in the majority of these patients. Palliative treatment is particularly indicated in the presence of cholangitis and pruritus but is often also offered for high-grade jaundice and abdominal pain. Endoscopic drainage by placing stents at endoscopic retrograde cholangio-pancreatography (ERCP) is usually the preferred modality of palliation. However, for advanced disease, percutaneous stenting has been shown to be superior to endoscopic stenting. Endosonography-guided biliary drainage is emerging as an alternative technique, particularly when ERCP is not possible or fails. Metal stents are usually preferred over plastic stents, both for ERCP and for percutaneous biliary drainage. There is no consensus as to whether it is necessary to place multiple stents within advanced hilar blocks or whether unilateral stenting would suffice. However, recent data have suggested that, contrary to previous belief, it is useful to drain more than 50% of the liver volume for favorable long-term results. In the presence of cholangitis, it is beneficial to drain all of the obstructed biliary segments. Surgical bypass plays a limited role in palliation and is offered primarily as a segment III bypass if, during a laparotomy for resection, the tumor is found to be unresectable. Photodynamic therapy and, more recently, radiofrequency ablation have been used as adjuvant therapies to improve the results of biliary stenting. The exact technique to be used for palliation is guided by the extent of the biliary involvement (Bismuth class) and the availability of local expertise. PMID:25232449

  9. ULK1 inhibits mTORC1 signaling, promotes multisite Raptor phosphorylation and hinders substrate binding

    PubMed Central

    Dunlop, Elaine A; Hunt, David K; Acosta-Jaquez, Hugo A; Fingar, Diane C

    2011-01-01

    Protein synthesis and autophagy work as two opposing processes to control cell growth in response to nutrient supply. The mammalian/mechanistic target of rapamycin complex 1 (mTORC1) pathway, which acts as a master regulator to control protein synthesis, has recently been shown to inhibit autophagy by phosphorylating and inactivating ULK1, an autophagy regulatory protein. ULK1 also inhibits phosphorylation of a mTORC1 substrate, S6K1, indicating that a complex signaling interplay exists between mTORC1 and ULK1. Here, we demonstrate that ULK1 induces multisite phosphorylation of Raptor in vivo and in vitro. Using phospho-specific antibodies we identify Ser855 and Ser859 as being strongly phosphorylated by ULK1, with moderate phosphorylation of Ser792 also observed. Interestingly, ULK1 overexpression also increases phosphorylation of Raptor Ser863 and the mTOR autophosphorylation site, Ser2481 in a mTORC1-dependent manner. Despite this evidence for heightened mTORC1 kinase activity following ULK1 overexpresssion, mTORC1-mediated phosphorylation of S6K1 and 4E-BP1 is significantly inhibited. ULK1 expression has no effect on protein-protein interactions between the components of mTORC1, but does reduce the ability of Raptor to bind to the substrate 4E-BP1. Furthermore, shRNA knockdown of ULK1 leads to increased phosphorylation of mTORC1 substrates and decreased phosphorylation of Raptor at Ser859 and Ser792. We propose a new mechanism whereby ULK1 contributes to mTORC1 inhibition through hindrance of substrate docking to Raptor. This is a novel negative feedback loop that occurs upon activation of autophagy to maintain mTORC1 inhibition when nutrient supplies are limiting. PMID:21460630

  10. KIF14 Promotes AKT Phosphorylation and Contributes to Chemoresistance in Triple-Negative Breast Cancer12

    PubMed Central

    Singel, Stina M.; Cornelius, Crystal; Zaganjor, Elma; Batten, Kimberly; Sarode, Venetia R.; Buckley, Dennis L.; Peng, Yan; John, George B.; Li, Hsiao C.; Sadeghi, Navid; Wright, Woodring E.; Lum, Lawrence; Corson, Timothy W.; Shay, Jerry W.

    2014-01-01

    Despite evidence that kinesin family member 14 (KIF14) can serve as a prognostic biomarker in various solid tumors, how it contributes to tumorigenesis remains unclear. We observed that experimental decrease in KIF14 expression increases docetaxel chemosensitivity in estrogen receptor–negative/progesterone receptor–negative/human epidermal growth factor receptor 2-negative, “triple-negative” breast cancers (TNBC). To investigate the oncogenic role of KIF14, we used noncancerous human mammary epithelial cells and ectopically expressed KIF14 and found increased proliferative capacity, increased anchorage-independent grown in vitro, and increased resistance to docetaxel but not to doxorubicin, carboplatin, or gemcitabine. Seventeen benign breast biopsies of BRCA1 or BRCA2 mutation carriers showed increased KIF14 mRNA expression by fluorescence in situ hybridization compared to controls with no known mutations in BRCA1 or BRCA2, suggesting increased KIF14 expression as a biomarker of high-risk breast tissue. Evaluation of 34 cases of locally advanced TNBC showed that KIF14 expression significantly correlates with chemotherapy-resistant breast cancer. KIF14 knockdown also correlates with decreased AKT phosphorylation and activity. Live-cell imaging confirmed an insulin-induced temporal colocalization of KIF14 and AKT at the plasma membrane, suggesting a potential role of KIF14 in promoting activation of AKT. An experimental small-molecule inhibitor of KIF14 was then used to evaluate the potential anticancer benefits of downregulating KIF14 activity. Inhibition of KIF14 shows a chemosensitizing effect and correlates with decreasing activation of AKT. Together, these findings show an early and critical role for KIF14 in the tumorigenic potential of TNBC, and therapeutic targeting of KIF14 is feasible and effective for TNBC. PMID:24784001

  11. Evidence that phosphorylation by the mitotic kinase Cdk1 promotes ICER monoubiquitination and nuclear delocalization

    SciTech Connect

    Memin, Elisabeth; Genzale, Megan; Crow, Marni; Molina, Carlos A.

    2011-10-15

    In contrast to normal prostatic cells, the transcriptional repressor Inducible cAMP Early Repressor (ICER) is undetected in the nuclei of prostate cancer cells. The molecular mechanisms for ICER abnormal expression in prostate cancer cells remained largely unknown. In this report data is presented demonstrating that ICER is phosphorylated by the mitotic kinase cdk1. Phosphorylation of ICER on a discrete residue targeted ICER to be monoubiquitinated. Different from unphosphorylated, phosphorylated and polyubiquitinated ICER, monoubiquitinated ICER was found to be cytosolic. Taken together, these results hinted on a mechanism for the observed abnormal subcellular localization of ICER in human prostate tumors.

  12. Pim1 kinase promotes angiogenesis through phosphorylation of endothelial nitric oxide synthase at Ser-633

    PubMed Central

    Chen, Ming; Yi, Bing; Zhu, Ni; Wei, Xin; Zhang, Guan-Xin; Huang, Shengdong; Sun, Jianxin

    2016-01-01

    Aims Posttranslational modification, such as phosphorylation, plays an essential role in regulating activation of endothelial NO synthase (eNOS). In the present study, we aim to determine whether eNOS could be phosphorylated and regulated by a novel serine/threonine–protein kinase Pim1 in vascular endothelial cells (ECs). Methods and results Using immunoprecipitation and protein kinase assays, we demonstrated that Pim1 specifically interacts with eNOS, which leads to a marked phosphorylation of eNOS at Ser-633 and increased production of nitric oxide (NO). Intriguingly, in response to VEGF stimulation, eNOS phosphorylation at Ser-633 exhibits two distinct phases: transient phosphorylation occurring between 0 and 60 min and sustained phosphorylation occurring between 2 and 24 h, which are mediated by the protein kinase A (PKA) and Pim1, respectively. Inhibiting Pim1 by either pharmacological inhibitor SMI-4a or the dominant-negative form of Pim1 markedly attenuates VEGF-induced tube formation, while Pim1 overexpression significantly increases EC tube formation and migration in an NO-dependent manner. Importantly, Pim1 expression and eNOS phosphorylation at Ser-633 were substantially decreased in high glucose-treated ECs and in the aorta of db/db diabetic mice. Increased Pim1 expression ameliorates impaired vascular angiogenesis in diabetic mice, as determined by an ex vivo aortic ring assay. Conclusion Our findings demonstrate Pim1 as a novel kinase that is responsible for the phosphorylation of eNOS at Ser-633 and enhances EC sprouting of aortic rings from diabetic mice, suggesting that Pim1 could potentially serve as a novel therapeutic target for revascularization strategies. PMID:26598507

  13. Filamin A phosphorylation by Akt promotes cell migration in response to arsenic

    PubMed Central

    Li, Lingzhi; Lu, Yongju; Stemmer, Paul M.; Chen, Fei

    2015-01-01

    We had previously reported that trivalent arsenic (As3+), a well-known environmental carcinogen, induces phosphorylation of several putative Akt substrates. In the present report, we characterized one of these substrates by immunoprecipitation and proteomics analysis. The results indicate that a cytoskeleton remodeling protein, filamin A, with a molecular weight around 280 kDa, is phosphorylated by Akt in HEK-293 cells treated with As3+, which was also confirmed in human bronchial epithelial cell line, BEAS-2B cells. Additional biochemical and biological studies revealed that serine 2152 (S2152) of filamin A is phosphorylated by activated Akt in the cells treated with As3+. To further confirm the importance of Akt-dependent filamin A S2152 phosphorylation in As3+-induced cell migration, we over-expressed either wild type filamin A or the mutated filamin A in which the S2152 was substituted with alanine (S2152A). The capability of cell migration was reduced significantly in the cells expressing the mutated filamin A (S2152A). Clinically, we found that increased expression of filamin A predicts poorer overall survival of the lung cancer patients with adenocarcinoma. Thus, these data suggest that Akt dependent filamin A phosphorylation is one of the key events in mediating As3+-induced carcinogenesis. Antagonizing Akt signaling can ameliorate As3+-induced filamin A phosphorylation and cell migration, which may serve as a molecular targeting strategy for malignancies associated with environmental As3+ exposure. PMID:25944616

  14. Filamin A phosphorylation by Akt promotes cell migration in response to arsenic.

    PubMed

    Li, Lingzhi; Lu, Yongju; Stemmer, Paul M; Chen, Fei

    2015-05-20

    We had previously reported that trivalent arsenic (As(3+)), a well-known environmental carcinogen, induces phosphorylation of several putative Akt substrates. In the present report, we characterized one of these substrates by immunoprecipitation and proteomics analysis. The results indicate that a cytoskeleton remodeling protein, filamin A, with a molecular weight around 280 kDa, is phosphorylated by Akt in HEK-293 cells treated with As(3+), which was also confirmed in human bronchial epithelial cell line, BEAS-2B cells. Additional biochemical and biological studies revealed that serine 2152 (S2152) of filamin A is phosphorylated by activated Akt in the cells treated with As(3+). To further confirm the importance of Akt-dependent filamin A S2152 phosphorylation in As(3+)-induced cell migration, we over-expressed either wild type filamin A or the mutated filamin A in which the S2152 was substituted with alanine (S2152A). The capability of cell migration was reduced significantly in the cells expressing the mutated filamin A (S2152A). Clinically, we found that increased expression of filamin A predicts poorer overall survival of the lung cancer patients with adenocarcinoma. Thus, these data suggest that Akt dependent filamin A phosphorylation is one of the key events in mediating As(3+)-induced carcinogenesis. Antagonizing Akt signaling can ameliorate As(3+)-induced filamin A phosphorylation and cell migration, which may serve as a molecular targeting strategy for malignancies associated with environmental As(3+) exposure.

  15. Epigallocatechin-3-gallate prevents oxidative phosphorylation deficit and promotes mitochondrial biogenesis in human cells from subjects with Down's syndrome.

    PubMed

    Valenti, Daniela; De Rasmo, Domenico; Signorile, Anna; Rossi, Leonardo; de Bari, Lidia; Scala, Iris; Granese, Barbara; Papa, Sergio; Vacca, Rosa Anna

    2013-04-01

    A critical role for mitochondrial dysfunction has been proposed in the pathogenesis of Down's syndrome (DS), a human multifactorial disorder caused by trisomy of chromosome 21, associated with mental retardation and early neurodegeneration. Previous studies from our group demonstrated in DS cells a decreased capacity of the mitochondrial ATP production system and overproduction of reactive oxygen species (ROS) in mitochondria. In this study we have tested the potential of epigallocatechin-3-gallate (EGCG) - a natural polyphenol component of green tea - to counteract the mitochondrial energy deficit found in DS cells. We found that EGCG, incubated with cultured lymphoblasts and fibroblasts from DS subjects, rescued mitochondrial complex I and ATP synthase catalytic activities, restored oxidative phosphorylation efficiency and counteracted oxidative stress. These effects were associated with EGCG-induced promotion of PKA activity, related to increased cellular levels of cAMP and PKA-dependent phosphorylation of the NDUFS4 subunit of complex I. In addition, EGCG strongly promoted mitochondrial biogenesis in DS cells, as associated with increase in Sirt1-dependent PGC-1α deacetylation, NRF-1 and T-FAM protein levels and mitochondrial DNA content. In conclusion, this study shows that EGCG is a promoting effector of oxidative phosphorylation and mitochondrial biogenesis in DS cells, acting through modulation of the cAMP/PKA- and sirtuin-dependent pathways. EGCG treatment promises thus to be a therapeutic approach to counteract mitochondrial energy deficit and oxidative stress in DS.

  16. Phosphorylation of PPARγ at Ser84 promotes glycolysis and cell proliferation in hepatocellular carcinoma by targeting PFKFB4

    PubMed Central

    Pang, Xiaojuan; Zheng, Wei; Huang, Yahong; Li, Jiahong; Ji, Jianguo; Zhang, Can; Shen, Pingping

    2016-01-01

    Peroxisome proliferator-activating receptor γ (PPARγ), a transcription factor, is involved in many important biological processes, including cell terminal differentiation, survival and apoptosis. However, the role of PPARγ, which regulates tumour promoter and oncogene expression, is not well understood in hepatocellular carcinoma (HCC). In the present study, based on evidence from clinical samples that phosphorylation of PPARγ at Ser84 is up-regulated in human liver tumours, we confirmed that phosphorylation of PPARγ was also significantly increased in an HCC mouse model and was increased by Mitogen-activated protein kinase (MEK)/ Extracellular-signal-regulated kinases (ERK) kinase. Next, we performed an RNA microarray analysis, and our data indicated that dephosphorylation of PPARγ at Ser84 affects the expression of glycolysis-related genes and pro-proliferation genes, which supposedly promote proliferation of HCC cells. Using a chromatin immunoprecipitation (ChIP) assay, we demonstrated that the observed PPARγ-mediated induction of 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 4 (PFKFB4) expression was directly modulated by the transcriptional activity of its promoter. Furthermore, using knockdown of PFKFB4, we elucidated that the stimulation of PPARγ phosphorylation on glycolysis and proliferation in HCC is dependent on PFKFB4. Together, these findings extend our understanding of how liver tumour cells reprogram their glycolytic pathways by post-translational modification of specific transcription factors and lay a foundation for the screening of new targets for the treatment of HCC. PMID:27769068

  17. NESH (Abi-3) is present in the Abi/WAVE complex but does not promote c-Abl-mediated phosphorylation.

    PubMed

    Hirao, Noriko; Sato, Seiichi; Gotoh, Tetsuya; Maruoka, Masahiro; Suzuki, Jun; Matsuda, Satoru; Shishido, Tomoyuki; Tani, Katsuko

    2006-11-27

    Abl interactor (Abi) was identified as an Abl tyrosine kinase-binding protein and subsequently shown to be a component of the macromolecular Abi/WAVE complex, which is a key regulator of Rac-dependent actin polymerization. Previous studies showed that Abi-1 promotes c-Abl-mediated phosphorylation of Mammalian Enabled (Mena) and WAVE2. In addition to Abi-1, mammals possess Abi-2 and NESH (Abi-3). In this study, we compared the three Abi proteins in terms of the promotion of c-Abl-mediated phosphorylation and the formation of Abi/WAVE complex. Although Abi-2, like Abi-1, promoted the c-Abl-mediated phosphorylation of Mena and WAVE2, NESH (Abi-3) had no such effect. This difference was likely due to their binding abilities as to c-Abl. Immunoprecipitation revealed that NESH (Abi-3) is present in the Abi/WAVE complex. Our results suggest that NESH (Abi-3), like Abi-1 and Abi-2, is a component of the Abi/WAVE complex, but likely plays a different role in the regulation of c-Abl.

  18. aPKC phosphorylates JAM-A at Ser285 to promote cell contact maturation and tight junction formation.

    PubMed

    Iden, Sandra; Misselwitz, Steve; Peddibhotla, Swetha S D; Tuncay, Hüseyin; Rehder, Daniela; Gerke, Volker; Robenek, Horst; Suzuki, Atsushi; Ebnet, Klaus

    2012-03-05

    The PAR-3-atypical protein kinase C (aPKC)-PAR-6 complex has been implicated in the development of apicobasal polarity and the formation of tight junctions (TJs) in vertebrate epithelial cells. It is recruited by junctional adhesion molecule A (JAM-A) to primordial junctions where aPKC is activated by Rho family small guanosine triphosphatases. In this paper, we show that aPKC can interact directly with JAM-A in a PAR-3-independent manner. Upon recruitment to primordial junctions, aPKC phosphorylates JAM-A at S285 to promote the maturation of immature cell-cell contacts. In fully polarized cells, S285-phosphorylated JAM-A is localized exclusively at the TJs, and S285 phosphorylation of JAM-A is required for the development of a functional epithelial barrier. Protein phosphatase 2A dephosphorylates JAM-A at S285, suggesting that it antagonizes the activity of aPKC. Expression of nonphosphorylatable JAM-A/S285A interferes with single lumen specification during cyst development in three-dimensional culture. Our data suggest that aPKC phosphorylates JAM-A at S285 to regulate cell-cell contact maturation, TJ formation, and single lumen specification.

  19. Tumor-promoting phorbol diesters cause the phosphorylation of epidermal growth factor receptors in normal human fibroblasts at threonine-654.

    PubMed Central

    Davis, R J; Czech, M P

    1985-01-01

    The effect of tumor-promoting phorbol diesters to potentiate the action of epidermal growth factor (EGF) on cell proliferation is associated with phosphorylation of EGF receptors, acute depression of EGF binding, and inhibition of EGF receptor tyrosine kinase activity. In the present studies, normal human fibroblasts and A431 carcinoma cells were labeled with [32P]phosphate and treated with and without 10 nM 4 beta-phorbol 12 beta-myristate 13 alpha-acetate (PMA). The EGF receptors then were isolated by immunoprecipitation and digested with trypsin. Analysis of the labeled receptor phosphopeptides by reversed-phase HPLC revealed that PMA induces the phosphorylation of a unique phosphopeptide containing [32P]phosphothreonine. Comparison of several chemical and physical properties of the 32P-labeled phosphopeptide with the primary structure of the EGF receptor suggested the identify Lys-Arg-Thr(P)-Leu-Arg. This was confirmed by direct demonstration that a synthetic peptide of this structure comigrates during HPLC and electrophoresis with the 32P-labeled phosphopeptide isolated from the EGF receptors of normal human fibroblasts. The phosphorylated site on the peptide corresponds to threonine-654 of the EGF receptor, which is located on the cytoplasmic side of the plasma membrane nine residues distant from the transmembrane domain. These data indicate that phosphorylation of the EGF receptor in human fibroblasts and A431 cells at threonine-654 may regulate the EGF receptor tyrosine kinase activity and the binding of EGF. Images PMID:2984676

  20. c-Src phosphorylation and activation of hexokinase promotes tumorigenesis and metastasis

    PubMed Central

    Zhang, Jia; Wang, Suili; Jiang, Bin; Huang, Lihong; Ji, Zhiliang; Li, Xiaotong; Zhou, Huamin; Han, Aidong; Chen, Ai; Wu, Yanan; Ma, Huanhuan; Zhao, Wentao; Zhao, Qingwen; Xie, Changchuan; Sun, Xiaoyan; Zhou, Yanming; Huang, Huiying; Suleman, Muhammad; Lin, Furong; Zhou, Lin; Tian, Fang; Jin, Meijun; Cai, Yana; Zhang, Nan; Li, Qinxi

    2017-01-01

    It is well known that c-Src has important roles in tumorigenesis. However, it remains unclear whether c-Src contributes to metabolic reprogramming. Here we find that c-Src can interact with and phosphorylate hexokinases HK1 and HK2, the rate-limiting enzymes in glycolysis. Tyrosine phosphorylation dramatically increases their catalytic activity and thus enhances glycolysis. Mechanistically, c-Src phosphorylation of HK1 at Tyr732 robustly decreases its Km and increases its Vmax by disrupting its dimer formation. Mutation in c-Src phosphorylation site of either HK1 or HK2 remarkably abrogates the stimulating effects of c-Src on glycolysis, cell proliferation, migration, invasion, tumorigenesis and metastasis. Due to its lower Km for glucose, HK1 rather than HK2 is required for tumour cell survival when glucose is scarce. Importantly, HK1-Y732 phosphorylation level remarkably correlates with the incidence and metastasis of various clinical cancers and may serve as a marker to predict metastasis risk of primary cancers. PMID:28054552

  1. Linker phosphorylation of Smad3 promotes fibro-carcinogenesis in chronic viral hepatitis of hepatocellular carcinoma.

    PubMed

    Murata, Miki; Yoshida, Katsunori; Yamaguchi, Takashi; Matsuzaki, Koichi

    2014-11-07

    Epidemiological and clinical data point to a close association between chronic hepatitis B virus infection or chronic hepatitis C virus infection and development of hepatocellular carcinoma (HCC). HCC develops over several decades and is associated with fibrosis. This sequence suggests that persistent viral infection and chronic inflammation can synergistically induce liver fibrosis and hepatocarcinogenesis. The transforming growth factor-β (TGF-β) signaling pathway plays a pivotal role in diverse cellular processes and contributes to hepatic fibro-carcinogenesis under inflammatory microenvironments during chronic liver diseases. The biological activities of TGF-β are initiated by the binding of the ligand to TGF-β receptors, which phosphorylate Smad proteins. TGF-β type I receptor activates Smad3 to create COOH-terminally phosphorylated Smad3 (pSmad3C), while pro-inflammatory cytokine-activated kinases phosphorylates Smad3 to create the linker phosphorylated Smad3 (pSmad3L). During chronic liver disease progression, virus components, together with pro-inflammatory cytokines and somatic mutations, convert the Smad3 signal from tumor-suppressive pSmad3C to fibro-carcinogenic pSmad3L pathways, accelerating liver fibrosis and increasing the risk of HCC. The understanding of Smad3 phosphorylation profiles may provide new opportunities for effective chemoprevention and personalized therapy for patients with hepatitis virus-related HCC in the future.

  2. TIPRL Inhibits Protein Phosphatase 4 Activity and Promotes H2AX Phosphorylation in the DNA Damage Response.

    PubMed

    Rosales, Kimberly Romero; Reid, Michael A; Yang, Ying; Tran, Thai Q; Wang, Wen-I; Lowman, Xazmin; Pan, Min; Kong, Mei

    2015-01-01

    Despite advances in our understanding of protein kinase regulation in the DNA damage response, the mechanism that controls protein phosphatase activity in this pathway is unclear. Unlike kinases, the activity and specificity of serine/threonine phosphatases is governed largely by their associated proteins. Here we show that Tip41-like protein (TIPRL), an evolutionarily conserved binding protein for PP2A-family phosphatases, is a negative regulator of protein phosphatase 4 (PP4). Knockdown of TIPRL resulted in increased PP4 phosphatase activity and formation of the active PP4-C/PP4R2 complex known to dephosphorylate γ-H2AX. Thus, overexpression of TIPRL promotes phosphorylation of H2AX, and increases γ-H2AX positive foci in response to DNA damage, whereas knockdown of TIPRL inhibits γ-H2AX phosphorylation. In correlation with γ-H2AX levels, we found that TIPRL overexpression promotes cell death in response to genotoxic stress, and knockdown of TIPRL protects cells from genotoxic agents. Taken together, these data demonstrate that TIPRL inhibits PP4 activity to allow for H2AX phosphorylation and the subsequent DNA damage response.

  3. Cholangiocarcinoma Presenting as Uterine Metastasis

    PubMed Central

    Dendas, W.; Cappelle, L.; Verguts, J.; Orye, G.

    2014-01-01

    Metastases to the female genital tract are rare, with metastatic disease restricted to the uterus being even less frequent. The primary tumor is most often intragenital rather than extragenital. The diagnosis is usually made after occurrence of gynecological symptoms. We describe the case of a 26-year-old female, in whom a curettage for menorrhagia revealed a uterine malignancy, at first thought to be a carcinosarcoma. Biochemistry only showed iron deficiency anemia. Imaging showed discrepant results with liver lesions, suspect of neoplastic or inflammatory disease. She underwent an abdominal hysterectomy and, peroperatively, a frozen section of a mass in the liver hilus demonstrated a cholangiocarcinoma. The diagnosis of a uterine metastasized cholangiocarcinoma was made. We emphasize the fact that uterine metastases have to be excluded in every woman with abnormal uterine bleeding and a personal history of malignancy. However, our case also indicates that gynecological metastatic disease may be the first presentation of an extragenital primary neoplasm. PMID:25610676

  4. Cholangiocarcinoma: increasing burden of classifications

    PubMed Central

    Cardinale, Vincenzo; Bragazzi, Maria Consiglia; Carpino, Guido; Torrice, Alessia; Fraveto, Alice; Gentile, Raffaele; Pasqualino, Vincenzo; Melandro, Fabio; Aliberti, Camilla; Bastianelli, Carlo; Brunelli, Roberto; Berloco, Pasquale Bartolomeo; Gaudio, Eugenio

    2013-01-01

    Cholangiocarcinoma (CCA) is a very heterogeneous cancer from any point of view, including epidemiology, risk factors, morphology, pathology, molecular pathology, modalities of growth and clinical features. Given this heterogeneity, a uniform classification respecting the epidemiologic, pathologic and clinical needs is currently lacking. In this manuscript we discussed the different proposed classifications of CCA in relation with recent advances in pathophysiology and biology of this cancer. PMID:24570958

  5. MAGE-C2 Promotes Growth and Tumorigenicity of Melanoma Cells, Phosphorylation of KAP1, and DNA Damage Repair

    PubMed Central

    Bhatia, Neehar; Xiao, Tony Z.; Rosenthal, Kimberly A.; Siddiqui, Imtiaz A.; Thiyagarajan, Saravanan; Smart, Brendan; Meng, Qiao; Zuleger, Cindy L.; Mukhtar, Hasan; Kenney, Shannon C.; Albertini, Mark R.; Longley, B. Jack

    2012-01-01

    Melanoma-associated antigen-encoding (MAGE) genes are expressed in melanoma and other cancers but not in normal somatic cells. MAGE expression is associated with aggressive tumor growth, poor clinical outcome, and resistance to chemotherapy, but the mechanisms have not been completely elucidated. In this study, we show that downregulation of MAGE-C2 in A375 melanoma cells and low-passage cultures from human metastatic melanomas (MRA cells) results in increased apoptosis and decreased growth of tumor xenografts in athymic nude mice. Previously, we showed that MAGE-C2 binds KAP1, a scaffolding protein that regulates DNA repair. Phosphorylation of KAP1-Serine 824 (Ser824) by ataxia-telangiectasia–mutated (ATM) kinase is necessary for repair of DNA double-strand breaks (DSBs); now we show that MAGE-C2 knockdown reduces, whereas MAGE-C2 overexpression increases, ATM kinase–dependent phosphorylation of KAP1-Ser824. We demonstrate that MAGE-C2 increases co-precipitation of KAP1 with ATM and that binding of MAGE-C2 to KAP1 is necessary for increased KAP1-Ser824 phosphorylation. Furthermore, ectopic expression of MAGE-C2 enhances repair of I-SceI endonuclease–induced DSBs in U-2OS cells. As phosphorylation of KAP1-Ser824 facilitates relaxation of heterochromatin, which is necessary for DNA repair and cellular proliferation, our results suggest that MAGE-C2 can promote tumor growth by phosphorylation of KAP1-Ser824 and by enhancement of DNA damage repair. PMID:23096706

  6. Identification of a fungal cutinase promoter that is inducible by a plant signal via a phosphorylated trans-acting factor.

    PubMed Central

    Bajar, A; Podila, G K; Kolattukudy, P E

    1991-01-01

    Plant cutin monomers trigger, and glucose suppresses, the expression of the cutinase gene of pathogenic fungi. To identify the cutinase promoter region responsible for induction by the unique plant components, a promoter analysis was done with transformants. Plasmids were constructed that contained (i) the 5' flanking region of the cutinase gene or its deletion mutants from Fusarium solani pisi fused with a chloramphenicol acetyltransferase (CAT) reporter gene and (ii) a constitutive promoter fused with a hygromycin phosphotransferase gene. Hygromycin-resistant transformants of F. solani pisi generated by electroporation were assayed for CAT activity inducible by cutin hydrolysate and for glucose repression of this induction. CAT was induced in a glucose-repressible manner when fused with a 360-base-pair (bp), or longer, segment of the 5' flanking region of the cutinase gene, and deletion of the next 135 bp abolished this induction. Gel retardation assays showed that a protein(s) in nuclear extract from the fungus bound to the 5' flanking region of cutinase gene, and this binding was also abolished when the same 135-bp segment was deleted. These results show that the -225 to -360 segment of the cutinase gene contains a cis-acting regulatory element that binds trans-acting factor(s) in the nuclei. Treatment of the nuclear extract with immobilized phosphatase abolished binding to the promoter, suggesting that binding required a phosphorylated form of the protein. With isolated nuclei, phosphorylation of a protein occurred only in the presence of both cutin monomer and the fungal protein factor. The presence of protein kinase inhibitor H7 during the preincubation of nuclei with the monomer and protein factor inhibited cutinase gene transcription. These results suggest that cutin monomer causes phosphorylation of a transcription factor that binds to the -225 to -360 segment of the cutinase gene and enhances transcription of this gene. Images PMID:1896470

  7. Unusual Paraneoplastic Presentation of Cholangiocarcinoma

    PubMed Central

    Opneja, Aman; Mahajan, Sonia; Kapoor, Sargam; Marur, Shanthi; Yang, Steve Hoseong; Manno, Rebecca

    2015-01-01

    Introduction. Cutaneous paraneoplastic syndromes are a heterogeneous group of skin manifestations that occur in relation to many known malignancies. Paraneoplastic occurrence of SCLE has been noted but is not commonly reported. SCLE association with cholangiocarcinoma is rare. Case Presentation. A 72-year-old man with a history of extrahepatic stage IV cholangiocarcinoma presented with a pruritic rash. Cholangiocarcinoma had been diagnosed three years earlier and was treated. Five months after interruption of his chemotherapy due to a semiurgent surgery, he presented with explosive onset of a new pruritic rash, arthralgias, and lower extremity edema. Physical exam revealed a scaly erythematous rash on his arms, hands, face, neck, legs, and trunk. It was thick and scaly on sun exposed areas. Skin biopsy revealed vacuolar interface dermatitis. Immunofluorescence revealed IgM positive cytoid bodies scattered along the epidermal basement membrane zone. PET-CT scanning revealed metabolically active recurrent disease in peripancreatic and periportal region with hypermetabolic lymph nodes. Oral steroids and new regimen of chemotherapy were started. Rash improved and steroids were tapered off. Discussion. Paraneoplastic syndromes demonstrate the complex interaction between the immune system and cancer. Treatment resistant SCLE should raise a suspicion for paraneoplastic etiology. PMID:26495003

  8. Perilipin Promotes HSL-Mediated Adipocyte Lipolysis via Phosphorylation-dependent and Independent Mechanisms

    USDA-ARS?s Scientific Manuscript database

    Hormone-sensitive lipase (HSL) is the predominant lipase effector of catecholamine-stimulated lipolysis in adipocytes. HSL-dependent lipolysis, in response to catecholamines, is mediated by protein kinase A (PKA)-dependent phosphorylation of perilipin A (Peri A), an essential lipid droplet (LD)-ass...

  9. ATM-dependent Phosphorylation of the Fanconi Anemia Protein PALB2 Promotes the DNA Damage Response.

    PubMed

    Guo, Yingying; Feng, Wanjuan; Sy, Shirley M H; Huen, Michael S Y

    2015-11-13

    The Fanconi anemia protein PALB2, also known as FANCN, protects genome integrity by regulating DNA repair and cell cycle checkpoints. Exactly how PALB2 functions may be temporally coupled with detection and signaling of DNA damage is not known. Intriguingly, we found that PALB2 is transformed into a hyperphosphorylated state in response to ionizing radiation (IR). IR treatment specifically triggered PALB2 phosphorylation at Ser-157 and Ser-376 in manners that required the master DNA damage response kinase Ataxia telangiectasia mutated, revealing potential mechanistic links between PALB2 and the Ataxia telangiectasia mutated-dependent DNA damage responses. Consistently, dysregulated PALB2 phosphorylation resulted in sustained activation of DDRs. Full-blown PALB2 phosphorylation also required the breast and ovarian susceptible gene product BRCA1, highlighting important roles of the BRCA1-PALB2 interaction in orchestrating cellular responses to genotoxic stress. In summary, our phosphorylation analysis of tumor suppressor protein PALB2 uncovers new layers of regulatory mechanisms in the maintenance of genome stability and tumor suppression. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  10. Expert consensus document: Cholangiocarcinoma: current knowledge and future perspectives consensus statement from the European Network for the Study of Cholangiocarcinoma (ENS-CCA).

    PubMed

    Banales, Jesus M; Cardinale, Vincenzo; Carpino, Guido; Marzioni, Marco; Andersen, Jesper B; Invernizzi, Pietro; Lind, Guro E; Folseraas, Trine; Forbes, Stuart J; Fouassier, Laura; Geier, Andreas; Calvisi, Diego F; Mertens, Joachim C; Trauner, Michael; Benedetti, Antonio; Maroni, Luca; Vaquero, Javier; Macias, Rocio I R; Raggi, Chiara; Perugorria, Maria J; Gaudio, Eugenio; Boberg, Kirsten M; Marin, Jose J G; Alvaro, Domenico

    2016-05-01

    Cholangiocarcinoma (CCA) is a heterogeneous group of malignancies with features of biliary tract differentiation. CCA is the second most common primary liver tumour and the incidence is increasing worldwide. CCA has high mortality owing to its aggressiveness, late diagnosis and refractory nature. In May 2015, the "European Network for the Study of Cholangiocarcinoma" (ENS-CCA: www.enscca.org or www.cholangiocarcinoma.eu) was created to promote and boost international research collaboration on the study of CCA at basic, translational and clinical level. In this Consensus Statement, we aim to provide valuable information on classifications, pathological features, risk factors, cells of origin, genetic and epigenetic modifications and current therapies available for this cancer. Moreover, future directions on basic and clinical investigations and plans for the ENS-CCA are highlighted.

  11. Oxidized Phospholipid Species Promote in Vivo Differential Cx43 Phosphorylation and Vascular Smooth Muscle Cell Proliferation

    PubMed Central

    Johnstone, Scott R.; Ross, Jeremy; Rizzo, Michael J.; Straub, Adam C.; Lampe, Paul D.; Leitinger, Norbert; Isakson, Brant E.

    2009-01-01

    Regulation of both the expression and function of connexins in the vascular wall is important during atherosclerosis. Progression of the disease state is marked by vascular smooth muscle cell (VSMC) proliferation, which coincides with the reduced expression levels of connexin 43 (Cx43). However, nothing is currently known about the factors that regulate post-translational modifications of Cx43 in atherogenesis, which could be of particular importance, due to the association between site-specific Cx43 phosphorylation and cellular proliferation. We compared the effects of direct carotid applications of two oxidized phospholipid derivatives, 1-palmitoyl-2-oxovaleroyl-sn-glycero-3-phosphorylcholine (POVPC) and 1-palmitoyl-2-glutaroyl-sn-glycero-3-phosphorylcholine (PGPC), on Cx43 expression and phosphorylation, and on cell proliferation. Since both POVPC and PGPC have been shown to act through different intracellular pathways, we hypothesized that each oxidized phospholipid species could induce differential Cx43 phosphorylation events in the cytoplasmically located carboxyl-terminal region of the protein, which could potentially enhance cell proliferation. Application of POVPC caused a reduction in VSMC Cx43 levels, enhanced its phosphorylation at serine (pS) 279/282, and increased VSMC proliferation both in vivo and in vitro. Treatment with PGPC enhanced VSMC pS368 levels with no associated change in proliferation. These oxidized phospholipid-induced Cx43 post-translational changes in VSMCs were consistent with those identified in ApoE−/− mice. Taken together, these results demonstrate that post-translational phosphorylation of Cx43 could be a key factor in the pathogenesis of atherosclerosis. PMID:19608875

  12. ULK1-mediated phosphorylation of ATG14 promotes autophagy and is impaired in Huntington's disease models.

    PubMed

    Wold, Mitchell S; Lim, Junghyun; Lachance, Véronik; Deng, Zhiqiang; Yue, Zhenyu

    2016-12-09

    Autophagy is a bulk degradation pathway for long-lived proteins, protein aggregates, and damaged organelles. ULK1 protein kinase and Vps34 lipid kinase are two key autophagy regulators that are critical for autophagosome biogenesis. However, it isn't fully understood how ULK1 regulates Vps34, especially in the context of disease. Polyglutamine expansion in huntingtin (Htt) causes aberrant accumulation of the aggregated protein and disrupts various cellular pathways including autophagy, a lysosomal degradation pathway, underlying the pathogenesis of Huntington's disease (HD). Although autophagic clearance of Htt aggregates is under investigation as therapeutic strategy for HD, the precise mechanism of autophagy impairment remains poorly understood. Moreover, in-vivo assays of autophagy have been particularly challenging due to lack of reliable and robust molecular biomarkers. We generated anti-phosphorylated ATG14 antibody to determine ATG14-mediated autophagy regulation; we employed Huntington's disease (HD) genetic cell models and animal models as well as autophagy reporter animal model to understand autophagy signaling and regulation in vivo. We applied biochemical analysis and molecular biology approaches to dissect the alteration of autophagy kinase activity and regulation. Here, we demonstrate that ULK1 phosphorylates ATG14 at serine 29 in an mTOR-dependent manner. This phosphorylation critically regulates ATG14-Vps34 lipid kinase activity to control autophagy level. We also show that ATG14-associated Vps34 activity and ULK1-mediated phosphorylation of ATG14 and Beclin 1 are compromised in the Q175 mouse model of Huntington's disease. Finally, we show that ATG14 phosphorylation is decreased during general proteotoxic stress caused by proteasomal inhibition. This reduction of the specific phosphorylation of ATG14 and Beclin 1 is mediated, in part, by p62-induced sequestration of ULK1 to an insoluble cellular fraction. We show that increased ULK1 levels and

  13. Tyrosine phosphorylation of RNA polymerase II CTD is associated with antisense promoter transcription and active enhancers in mammalian cells

    PubMed Central

    Descostes, Nicolas; Heidemann, Martin; Spinelli, Lionel; Schüller, Roland; Maqbool, Muhammad Ahmad; Fenouil, Romain; Koch, Frederic; Innocenti, Charlène; Gut, Marta; Gut, Ivo; Eick, Dirk; Andrau, Jean-Christophe

    2014-01-01

    In mammals, the carboxy-terminal domain (CTD) of RNA polymerase (Pol) II consists of 52 conserved heptapeptide repeats containing the consensus sequence Tyr1-Ser2-Pro3-Thr4-Ser5-Pro6-Ser7. Post-translational modifications of the CTD coordinate the transcription cycle and various steps of mRNA maturation. Here we describe Tyr1 phosphorylation (Tyr1P) as a hallmark of promoter (5′ associated) Pol II in mammalian cells, in contrast to what was described in yeast. Tyr1P is predominantly found in antisense orientation at promoters but is also specifically enriched at active enhancers. Mutation of Tyr1 to phenylalanine (Y1F) prevents the formation of the hyper-phosphorylated Pol IIO form, induces degradation of Pol II to the truncated Pol IIB form, and results in a lethal phenotype. Our results suggest that Tyr1P has evolved specialized and essential functions in higher eukaryotes associated with antisense promoter and enhancer transcription, and Pol II stability. DOI: http://dx.doi.org/10.7554/eLife.02105.001 PMID:24842994

  14. PI(4)P Promotes Phosphorylation and Conformational Change of Smoothened through Interaction with Its C-terminal Tail

    PubMed Central

    Zhang, Jie; Li, Xiang-An; Evers, B. Mark; Zhu, Haining; Jia, Jianhang

    2016-01-01

    In Hedgehog (Hh) signaling, binding of Hh to the Patched-Interference Hh (Ptc-Ihog) receptor complex relieves Ptc inhibition on Smoothened (Smo). A longstanding question is how Ptc inhibits Smo and how such inhibition is relieved by Hh stimulation. In this study, we found that Hh elevates production of phosphatidylinositol 4-phosphate (PI(4)P). Increased levels of PI(4)P promote, whereas decreased levels of PI(4)P inhibit, Hh signaling activity. We further found that PI(4)P directly binds Smo through an arginine motif, which then triggers Smo phosphorylation and activation. Moreover, we identified the pleckstrin homology (PH) domain of G protein-coupled receptor kinase 2 (Gprk2) as an essential component for enriching PI(4)P and facilitating Smo activation. PI(4)P also binds mouse Smo (mSmo) and promotes its phosphorylation and ciliary accumulation. Finally, Hh treatment increases the interaction between Smo and PI(4)P but decreases the interaction between Ptc and PI(4)P, indicating that, in addition to promoting PI(4)P production, Hh regulates the pool of PI(4)P associated with Ptc and Smo. PMID:26863604

  15. APCste9/srw1 promotes degradation of mitotic cyclins in G1 and is inhibited by cdc2 phosphorylation

    PubMed Central

    Blanco, Miguel A.; Sánchez-Díaz, Alberto; de Prada, José M.; Moreno, Sergio

    2000-01-01

    Fission yeast ste9/srw1 is a WD-repeat protein highly homologous to budding yeast Hct1/Cdh1 and Drosophila Fizzy-related that are involved in activating APC/C (anaphase-promoting complex/cyclosome). We show that APCste9/srw1 specifically promotes the degradation of mitotic cyclins cdc13 and cig1 but not the S-phase cyclin cig2. APCste9/srw1 is not necessary for the proteolysis of cdc13 and cig1 that occurs at the metaphase–anaphase transition but it is absolutely required for their degradation in G1. Therefore, we propose that the main role of APCste9/srw1 is to promote degradation of mitotic cyclins when cells need to delay or arrest the cell cycle in G1. We also show that ste9/srw1 is negatively regulated by cdc2-dependent protein phosphorylation. In G1, when cdc2–cyclin kinase activity is low, unphosphorylated ste9/srw1 interacts with APC/C. In the rest of the cell cycle, phosphorylation of ste9/srw1 by cdc2–cyclin complexes both triggers proteolysis of ste9/srw1 and causes its dissociation from the APC/C. This mechanism provides a molecular switch to prevent inactivation of cdc2 in G2 and early mitosis and to allow its inactivation in G1. PMID:10921876

  16. Aurora A kinase amplifies a midzone phosphorylation gradient to promote high fidelity cytokinesis

    PubMed Central

    Ye, Anna A.; Torabi, Julia; Maresca, Thomas J.

    2017-01-01

    Aurora B kinase (ABK) re-localizes from centromeres to the spindle midzone during cytokinesis where it is thought to provide a spatial cue for cytokinesis. While global ABK inhibition in Drosophila S2 cells results in macro- and multi-nucleated large cells, mis-localization of midzone ABK (mABK) by depletion of Subito (Drosophila MKLP2) does not cause notable cytokinesis defects. Subito depletion was; therefore, used to investigate the contribution of other molecules and redundant pathways to cytokinesis in the absence of mABK. Inhibiting potential polar relaxation pathways via removal of centrosomes (CNN RNAi) or a kinetochore-based phosphatase-gradient (Sds22 RNAi) did not result in cytokinesis defects on their own or in combination with loss of mABK. Disruption of Aurora A kinase (AAK) activity resulted in midzone assembly defects but did not significantly affect contractile ring positioning or cytokinesis. Live-cell imaging of a FRET-based aurora kinase phosphorylation sensor revealed that midzone substrates were less phosphorylated in AAK-inhibited cells, despite the fact that midzone levels of active phosphorylated ABK (pABK) were normal. Interestingly, an increased number of binucleated cells were observed following AAK inhibition in the absence of mABK. The data suggest that equatorial stimulation rather than polar relaxation mechanisms are the major determinants of contractile ring positioning and high-fidelity cytokinesis in Drosophila S2 cells. Furthermore, we propose that equatorial stimulation is mediated primarily by the delivery of factors to the cortex by non-centrosomal microtubules (MTs) as well as a midzone-derived phosphorylation gradient that is amplified by the concerted activities of mABK and a soluble pool of AAK. PMID:27638695

  17. Phosphorylation of CHIP at Ser20 by Cdk5 promotes tAIF-mediated neuronal death.

    PubMed

    Kim, C; Yun, N; Lee, J; Youdim, M B H; Ju, C; Kim, W-K; Han, P-L; Oh, Y J

    2016-02-01

    Cyclin-dependent kinase 5 (Cdk5) is a proline-directed serine/threonine kinase and its dysregulation is implicated in neurodegenerative diseases. Likewise, C-terminus of Hsc70-interacting protein (CHIP) is linked to neurological disorders, serving as an E3 ubiquitin ligase for targeting damaged or toxic proteins for proteasomal degradation. Here, we demonstrate that CHIP is a novel substrate for Cdk5. Cdk5 phosphorylates CHIP at Ser20 via direct binding to a highly charged domain of CHIP. Co-immunoprecipitation and ubiquitination assays reveal that Cdk5-mediated phosphorylation disrupts the interaction between CHIP and truncated apoptosis-inducing factor (tAIF) without affecting CHIP's E3 ligase activity, resulting in the inhibition of CHIP-mediated degradation of tAIF. Lentiviral transduction assay shows that knockdown of Cdk5 or overexpression of CHIP(S20A), but not CHIP(WT), attenuates tAIF-mediated neuronal cell death induced by hydrogen peroxide. Thus, we conclude that Cdk5-mediated phosphorylation of CHIP negatively regulates its neuroprotective function, thereby contributing to neuronal cell death progression following neurotoxic stimuli.

  18. Depletion of the Adaptor Protein NCK Increases UV-Induced p53 Phosphorylation and Promotes Apoptosis

    PubMed Central

    Errington, Timothy M.; Macara, Ian G.

    2013-01-01

    The cellular response to DNA damage requires the coordination of many proteins involved in diverse molecular processes. Discrete molecular pathways are becoming increasingly well understood, but the interconnectivity and coordination of multiple pathways remains less clear. We now show that NCK, an adapter protein involved in cytoskeletal responses to tyrosine kinase receptor signaling, accumulates in the nucleus in response to DNA damage and this translocation can be blocked by specific inhibition of the ATR protein kinase. Strikingly, HeLa cells depleted of NCK undergo apoptosis shortly after UV irradiation, as monitored by caspase-3 cleavage and PARP cleavage. This rapid, hyperactive apoptosis in NCK depleted cells might be p53 dependent, because loss of NCK also increased UV-induced p53 phosphorylation. Importantly, depletion of SOCS7, which is necessary for NCK nuclear translocation, phenocopies NCK depletion, indicating the nuclear accumulation of NCK is responsible for these molecular events. There are two NCK isoforms that have mostly redundant functions, and although NCK2 appears to have a greater contribution, depletion of NCK1 or NCK2, led to increased p53 phosphorylation and early apoptosis after UV exposure. These data reveal a novel function for NCK in regulating p53 phosphorylation and apoptosis, and provide evidence for interconnectedness of growth factor signaling proteins and the DNA damage response. PMID:24086708

  19. PKA-regulated VASP phosphorylation promotes extrusion of transformed cells from the epithelium

    PubMed Central

    Anton, Katarzyna A.; Sinclair, John; Ohoka, Atsuko; Kajita, Mihoko; Ishikawa, Susumu; Benz, Peter M.; Renne, Thomas; Balda, Maria; Matter, Karl; Fujita, Yasuyuki

    2014-01-01

    ABSTRACT At the early stages of carcinogenesis, transformation occurs in single cells within tissues. In an epithelial monolayer, such mutated cells are recognized by their normal neighbors and are often apically extruded. The apical extrusion requires cytoskeletal reorganization and changes in cell shape, but the molecular switches involved in the regulation of these processes are poorly understood. Here, using stable isotope labeling by amino acids in cell culture (SILAC)-based quantitative mass spectrometry, we have identified proteins that are modulated in transformed cells upon their interaction with normal cells. Phosphorylation of VASP at serine 239 is specifically upregulated in RasV12-transformed cells when they are surrounded by normal cells. VASP phosphorylation is required for the cell shape changes and apical extrusion of Ras-transformed cells. Furthermore, PKA is activated in Ras-transformed cells that are surrounded by normal cells, leading to VASP phosphorylation. These results indicate that the PKA–VASP pathway is a crucial regulator of tumor cell extrusion from the epithelium, and they shed light on the events occurring at the early stage of carcinogenesis. PMID:24963131

  20. α-Catenin phosphorylation promotes intercellular adhesion through a dual-kinase mechanism

    PubMed Central

    Escobar, David J.; Desai, Ridhdhi; Ishiyama, Noboru; Folmsbee, Stephen S.; Novak, Megan N.; Flozak, Annette S.; Daugherty, Rebecca L.; Mo, Rigen; Nanavati, Dhaval; Sarpal, Ritu; Leckband, Deborah; Ikura, Mitsu; Tepass, Ulrich; Gottardi, Cara J.

    2015-01-01

    ABSTRACT The cadherin–catenin adhesion complex is a key contributor to epithelial tissue stability and dynamic cell movements during development and tissue renewal. How this complex is regulated to accomplish these functions is not fully understood. We identified several phosphorylation sites in mammalian αE-catenin (also known as catenin α-1) and Drosophila α-Catenin within a flexible linker located between the middle (M)-region and the carboxy-terminal actin-binding domain. We show that this phospho-linker (P-linker) is the main phosphorylated region of α-catenin in cells and is sequentially modified at casein kinase 2 and 1 consensus sites. In Drosophila, the P-linker is required for normal α-catenin function during development and collective cell migration, although no obvious defects were found in cadherin–catenin complex assembly or adherens junction formation. In mammalian cells, non-phosphorylatable forms of α-catenin showed defects in intercellular adhesion using a mechanical dispersion assay. Epithelial sheets expressing phosphomimetic forms of α-catenin showed faster and more coordinated migrations after scratch wounding. These findings suggest that phosphorylation and dephosphorylation of the α-catenin P-linker are required for normal cadherin–catenin complex function in Drosophila and mammalian cells. PMID:25653389

  1. Phosphorylation of CHIP at Ser20 by Cdk5 promotes tAIF-mediated neuronal death

    PubMed Central

    Kim, C; Yun, N; Lee, J; Youdim, M B H; Ju, C; Kim, W-K; Han, P-L; Oh, Y J

    2016-01-01

    Cyclin-dependent kinase 5 (Cdk5) is a proline-directed serine/threonine kinase and its dysregulation is implicated in neurodegenerative diseases. Likewise, C-terminus of Hsc70-interacting protein (CHIP) is linked to neurological disorders, serving as an E3 ubiquitin ligase for targeting damaged or toxic proteins for proteasomal degradation. Here, we demonstrate that CHIP is a novel substrate for Cdk5. Cdk5 phosphorylates CHIP at Ser20 via direct binding to a highly charged domain of CHIP. Co-immunoprecipitation and ubiquitination assays reveal that Cdk5-mediated phosphorylation disrupts the interaction between CHIP and truncated apoptosis-inducing factor (tAIF) without affecting CHIP's E3 ligase activity, resulting in the inhibition of CHIP-mediated degradation of tAIF. Lentiviral transduction assay shows that knockdown of Cdk5 or overexpression of CHIPS20A, but not CHIPWT, attenuates tAIF-mediated neuronal cell death induced by hydrogen peroxide. Thus, we conclude that Cdk5-mediated phosphorylation of CHIP negatively regulates its neuroprotective function, thereby contributing to neuronal cell death progression following neurotoxic stimuli. PMID:26206088

  2. Chlorogenic acid ameliorates endotoxin-induced liver injury by promoting mitochondrial oxidative phosphorylation

    SciTech Connect

    Zhou, Yan; Ruan, Zheng; Zhou, Lili; Shu, Xugang; Sun, Xiaohong; Mi, Shumei; Yang, Yuhui; Yin, Yulong

    2016-01-22

    Acute or chronic hepatic injury is a common pathology worldwide. Mitochondrial dysfunction and the depletion of adenosine triphosphate (ATP) play important roles in liver injury. Chlorogenic acids (CGA) are some of the most abundant phenolic acids in human diet. This study was designed to test the hypothesis that CGA may protect against chronic lipopolysaccharide (LPS)-induced liver injury by modulating mitochondrial energy generation. CGA decreased the activities of serum alanine aminotransferase, aspartate aminotransferase and alkaline phosphatase. The contents of ATP and adenosine monophosphate (AMP), as well as the ratio of AMP/ATP, were increased after CGA supplementation. The activities of enzymes that are involved in glycolysis were reduced, while those of enzymes involved in oxidative phosphorylation were increased. Moreover, phosphorylated AMP-activated protein kinase (AMPK), and mRNA levels of AMPK-α, peroxisome proliferator-activated receptor-gamma coactivator 1α (PGC-1α), nuclear respiratory factor 1, and mitochondrial DNA transcription factor A were increased after CGA supplementation. Collectively, these findings suggest that the hepatoprotective effect of CGA might be associated with enhanced ATP production, the stimulation of mitochondrial oxidative phosphorylation and the inhibition of glycolysis. - Highlights: • Dietary supplementation with chlorogenic acid (CGA) improved endotoxin-induced liver injury. • Chlorogenic acid enhances ATP increase and shifts energy metabolism, which is correlated with up-regulation AMPK and PGC-1α. • The possible mechanism of CGA on mitochondrial biogenesis was correlated with up-regulation AMPK and PGC-1α.

  3. Morphine Promotes Astrocyte-Preferential Differentiation of Mouse Hippocampal Progenitor Cells via PKCε-Dependent ERK Activation and TRBP Phosphorylation.

    PubMed

    Xu, Chi; Zheng, Hui; Loh, Horace H; Law, Ping-Yee

    2015-09-01

    Previously we have shown that morphine regulates adult neurogenesis by modulating miR-181a maturation and subsequent hippocampal neural progenitor cell (NPC) lineages. Using NPCs cultured from PKCε or β-arrestin2 knockout mice and the MAPK/ERK kinase inhibitor U0126, we demonstrate that regulation of NPC differentiation via the miR-181a/Prox1/Notch1 pathway exhibits ligand-dependent selectivity. In NPCs, morphine and fentanyl activate ERK via the PKCε- and β-arrestin-dependent pathways, respectively. After fentanyl exposure, the activated phospho-ERK translocates to the nucleus. Conversely, after morphine treatment, phospho-ERK remains in the cytosol and is capable of phosphorylating TAR RNA-binding protein (TRBP), a cofactor of Dicer. This augments Dicer activity and promotes the maturation of miR-181a. Furthermore, using NPCs transfected with wild-type TRBP, SΔA, and SΔD TRBP mutants, we confirmed the crucial role of TRBP phosphorylation in Dicer activity, miR-181a maturation, and finally the morphine-induced astrocyte-preferential differentiation of NPCs. Thus, morphine modulates the lineage-specific differentiation of NPCs by PKCε-dependent ERK activation with subsequent TRBP phosphorylation and miR-181a maturation.

  4. Phosphorylation of cohesin Rec11/SA3 by casein kinase 1 promotes homologous recombination by assembling the meiotic chromosome axis.

    PubMed

    Sakuno, Takeshi; Watanabe, Yoshinori

    2015-01-26

    In meiosis, cohesin is required for sister chromatid cohesion, as well as meiotic chromosome axis assembly and recombination. However, mechanisms underlying the multifunctional nature of cohesin remain elusive. Here, we show that fission yeast casein kinase 1 (CK1) plays a crucial role in assembling the meiotic chromosome axis (so-called linear element: LinE) and promoting recombination. An in vitro phosphorylation screening assay identified meiotic cohesin subunit Rec11/SA3 as an excellent substrate of CK1. The phosphorylation of Rec11 by CK1 mediates the interaction with the Rec10/Red1/SCP2 axis component, a key step in meiotic chromosome axis assembly, and is dispensable for sister chromatid cohesion. Crucially, the expression of Rec11-Rec10 fusion protein nearly completely bypasses the requirement for CK1 or cohesin phosphorylation for LinE assembly and recombination. This study uncovers a central mechanism of the cohesin-dependent assembly of the meiotic chromosome axis and recombination apparatus that acts independently of sister chromatid cohesion. Copyright © 2015 Elsevier Inc. All rights reserved.

  5. HIF-2α phosphorylation by CK1δ promotes erythropoietin secretion in liver cancer cells under hypoxia.

    PubMed

    Pangou, Evanthia; Befani, Christina; Mylonis, Ilias; Samiotaki, Martina; Panayotou, George; Simos, George; Liakos, Panagiotis

    2016-11-15

    Hypoxia inducible factor 2 (HIF-2) is a transcriptional activator implicated in the cellular response to hypoxia. Regulation of its inducible subunit, HIF-2α (also known as EPAS1), involves post-translational modifications. Here, we demonstrate that casein kinase 1δ (CK1δ; also known as CSNK1D) phosphorylates HIF-2α at Ser383 and Thr528 in vitro We found that disruption of these phosphorylation sites, and silencing or chemical inhibition of CK1δ, reduced the expression of HIF-2 target genes and the secretion of erythropoietin (EPO) in two hepatic cancer cell lines, Huh7 and HepG2, without affecting the levels of HIF-2α protein expression. Furthermore, when CK1δ-dependent phosphorylation of HIF-2α was inhibited, we observed substantial cytoplasmic mislocalization of HIF-2α, which was reversed upon the addition of the nuclear protein export inhibitor leptomycin B. Taken together, these data suggest that CK1δ enhances EPO secretion from liver cancer cells under hypoxia by modifying HIF-2α and promoting its nuclear accumulation. This modification represents a new mechanism of HIF-2 regulation that might allow HIF isoforms to undertake differing functions.

  6. Phosphorylation of Ser8 promotes zinc-induced dimerization of the amyloid-β metal-binding domain.

    PubMed

    Kulikova, Alexandra A; Tsvetkov, Philipp O; Indeykina, Maria I; Popov, Igor A; Zhokhov, Sergey S; Golovin, Andrey V; Polshakov, Vladimir I; Kozin, Sergey A; Nudler, Evgeny; Makarov, Alexander A

    2014-10-01

    Zinc-induced aggregation of the amyloid-β peptide (Aβ) is a hallmark molecular feature of Alzheimer's disease (AD). Recently it was shown that phosphorylation of Aβ at Ser8 promotes the formation of toxic aggregates. In this work, we have studied the impact of Ser8 phosphorylation on the mode of zinc interaction with the Aβ metal-binding domain 1-16 using isothermal titration calorimetry, electrospray ionization mass spectrometry and NMR spectroscopy. We have discovered a novel zinc binding site ((6)HDpS(8)) in the phosphorylated peptide, in which the zinc ion is coordinated by the imidazole ring of His6, the phosphate group attached to Ser8 and a backbone carbonyl group of His6 or Asp7. Interaction of the zinc ion with this site involves His6, thereby withdrawing it from the interaction pattern observed in the non-modified peptide. This event was found to stimulate dimerization of peptide chains through the (11)EVHH(14) site, where the zinc ion is coordinated by the two pairs of Glu11 and His14 in the two peptide subunits. The proposed molecular mechanism of zinc-induced dimerization could contribute to the understanding of initiation of pathological Aβ aggregation, and the (11)EVHH(14) tetrapeptide can be considered as a promising drug target for the prevention of amyloidogenesis.

  7. Glucocorticoid-mediated activation of GSK3β promotes tau phosphorylation and impairs memory in type 2 diabetes.

    PubMed

    Dey, Aditi; Hao, Shuai; Wosiski-Kuhn, Marlena; Stranahan, Alexis M

    2017-09-01

    Type 2 diabetes is increasingly recognized as a risk factor for Alzheimer's disease, but the underlying mechanisms remain poorly understood. Hyperphosphorylation of the microtubule-associated protein tau has been reported in rodent models of diabetes, including db/db mice, which exhibit insulin resistance and chronically elevated glucocorticoids due to leptin receptor insufficiency. In this report, we investigated endocrine mechanisms for hippocampal tau phosphorylation in db/db and wild-type mice. By separately manipulating peripheral and intrahippocampal corticosterone levels, we determined that hippocampal corticosteroid exposure promotes tau phosphorylation and activates glycogen synthase kinase 3β (GSK3β). Subsequent experiments in hippocampal slice preparations revealed evidence for a nongenomic interaction between glucocorticoids and GSK3β. To examine whether GSK3β activation mediates tau phosphorylation and impairs memory in diabetes, db/db and wild-type mice received intrahippocampal infusions of TDZD-8, a non-ATP competitive thiadiazolidinone inhibitor of GSK3β. Intrahippocampal TDZD-8 blocked tau hyperphosphorylation and normalized hippocampus-dependent memory in db/db mice, suggesting that pathological synergy between diabetes and Alzheimer's disease may involve glucocorticoid-mediated activation of GSK3β. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Estrogens and Insulin-Like Growth Factor 1 Modulate Neoplastic Cell Growth in Human Cholangiocarcinoma

    PubMed Central

    Alvaro, Domenico; Barbaro, Barbara; Franchitto, Antonio; Onori, Paolo; Glaser, Shannon S.; Alpini, Gianfranco; Francis, Heather; Marucci, Luca; Sterpetti, Paola; Ginanni-Corradini, Stefano; Onetti Muda, Andrea; Dostal, David E.; De Santis, Adriano; Attili, Adolfo F.; Benedetti, Antonio; Gaudio, Eugenio

    2006-01-01

    We investigated the expression of estrogen receptors (ERs), insulin-like growth factor 1 (IGF-1), and IGF-1R (receptor) in human cholangiocarcinoma and cholangiocarcinoma cell lines (HuH-28, TFK-1, Mz-ChA-1), evaluating the role of estrogens and IGF-1 in the modulation of neoplastic cell growth. ER-α, ER-β, IGF-1, and IGF-1R were expressed (immunohistochemistry) in all biopsies (18 of 18) of intrahepatic cholangiocarcinoma. ER-α was expressed (Western blot) only by the HuH-28 cell line (intrahepatic cholangiocarcinoma), whereas ER-β, IGF-1, and IGF-1R were expressed in the three cell lines examined. In serum-deprived HuH-28 cells, serum readmission induced stimulation of cell proliferation that was inhibited by ER and IGF-1R antagonists. 17β-Estradiol and IGF-1 stimulated proliferation of HuH-28 cells to a similar extent to that of MCF7 (breast cancer) but greater than that of TFK-1 and Mz-ChA-1, inhibiting apoptosis and exerting additive effects. These effects of 17β-estradiol and IGF-1 were associated with enhanced protein expression of ER-α, phosphorylated (p)-ERK1/2 and pAKT but with decreased expression of ER-β. Finally, transfection of IGF-1R anti-sense oligonucleotides in HuH-28 cells markedly decreased cell proliferation. In conclusion, human intrahepatic cholangiocarcinomas express receptors for estrogens and IGF-1, which cooperate in the modulation of cell growth and apoptosis. Modulation of ER and IGF-1R could represent a strategy for the management of cholangiocarcinoma. PMID:16936263

  9. Btk29A-mediated tyrosine phosphorylation of armadillo/β-catenin promotes ring canal growth in Drosophila oogenesis.

    PubMed

    Hamada-Kawaguchi, Noriko; Nishida, Yasuyoshi; Yamamoto, Daisuke

    2015-01-01

    Drosophila Btk29A is the ortholog of mammalian Btk, a Tec family nonreceptor tyrosine kinase whose deficit causes X-linked agammaglobulinemia in humans. The Btk29AficP mutation induces multiple abnormalities in oogenesis, including the growth arrest of ring canals, large intercellular bridges that allow the flow of cytoplasm carrying maternal products essential for embryonic development from the nurse cells to the oocyte during oogenesis. In this study, inactivation of Parcas, a negative regulator of Btk29A, was found to promote Btk29A accumulation on ring canals with a concomitant increase in the ring canal diameter, counteracting the Btk29AficP mutation. This mutation markedly reduced the accumulation of phosphotyrosine on ring canals and in the regions of cell-cell contact, where adhesion-supporting proteins such as DE-cadherin and β-catenin ortholog Armadillo (Arm) are located. Our previous in vitro and in vivo analyses revealed that Btk29A directly phosphorylates Arm, leading to its release from DE-cadherin. In the present experiments, immunohistological analysis revealed that phosphorylation at tyrosine 150 (Y150) and Y667 of Arm was diminished in Btk29AficP mutant ring canals. Overexpression of an Arm mutant with unphosphorylatable Y150 inhibited ring canal growth. Thus Btk29A-induced Y150 phosphorylation is necessary for the normal growth of ring canals. We suggest that the dissociation of tyrosine-phosphorylated Arm from DE-cadherin allows dynamic actin to reorganize, leading to ring canal expansion and cell shape changes during the course of oogenesis.

  10. A docking interface in the cyclin Cln2 promotes multisite phosphorylation of substrates and timely cell cycle entry

    PubMed Central

    Bhaduri, Samyabrata; Valk, Ervin; Winters, Matthew J.; Gruessner, Brian; Loog, Mart; Pryciak, Peter M.

    2014-01-01

    Summary Background Eukaryotic cell division is driven by cyclin-dependent kinases (CDKs). Distinct cyclin-CDK complexes are specialized to drive different cell cycle events, though the molecular foundations for these specializations are only partly understood. In budding yeast, the decision to begin a new cell cycle is regulated by three G1 cyclins (Cln1–Cln3). Recent studies revealed that some CDK substrates contain a novel docking motif that is specifically recognized by Cln1 and Cln2, and not by Cln3 or later S- or M-phase cyclins, but the responsible cyclin interface was unknown. Results Here, to explore the role of this new docking mechanism in the cell cycle, we first show that it is conserved in a distinct cyclin subtype (Ccn1). Then, we exploit phylogenetic variation to identify cyclin mutations that disrupt docking. These mutations disrupt binding to multiple substrates as well as the ability to use docking sites to promote efficient, multi-site phosphorylation of substrates in vitro. In cells where the Cln2 docking function is blocked, we observed reductions in the polarized morphogenesis of daughter buds and reduced ability to fully phosphorylate the G1/S transcriptional repressor Whi5. Furthermore, disruption of Cln2 docking perturbs the coordination between cell size and division, such that the G1/S transition is delayed. Conclusions The findings point to a novel substrate interaction interface on cyclins, with patterns of conservation and divergence that relate to functional distinctions among cyclin subtypes. Furthermore, this docking function helps ensure full phosphorylation of substrates with multiple phosphorylation sites, and this contributes to punctual cell cycle entry. PMID:25619768

  11. Distinct Effects of Mitogens and the Actin Cytoskeleton on CREB and Pocket Protein Phosphorylation Control the Extent and Timing of Cyclin A Promoter Activity

    PubMed Central

    Bottazzi, Maria Elena; Buzzai, Monica; Zhu, Xiaoyun; Desdouets, Chantal; Bréchot, Christian; Assoian, Richard K.

    2001-01-01

    Soluble mitogens and adhesion-dependent organization of the actin cytoskeleton are required for cells to enter S phase in fibroblasts. The induction of cyclin A is also required for S-phase entry, and we now report that distinct effects of mitogens and the actin cytoskeleton on the phosphorylation of CREB and pocket proteins regulate the extent and timing of cyclin A promoter activity, respectively. First, we show that CREB phosphorylation and binding to the cyclic AMP response element (CRE) determines the extent, but not the timing, of cyclin A promoter activity. Second, we show that pocket protein inactivation regulates the timing, but not the extent, of cyclin A promoter activity. CREB phosphorylation and CRE occupancy are regulated by soluble mitogens alone, while the phosphorylation of pocket proteins requires both mitogens and the organized actin cytoskeleton. Mechanistically, cytoskeletal integrity controls pocket protein phosphorylation by allowing for sustained ERK signaling and, thereby, the expression of cyclin D1. Our results lead to a model of cyclin A gene regulation in which mitogens play a permissive role by stimulating early G1-phase phosphorylation of CREB and a distinct regulatory role by cooperating with the organized actin cytoskeleton to regulate the duration of ERK signaling, the expression of cyclin D1, and the timing of pocket protein phosphorylation. PMID:11604497

  12. Dynamic Phosphorylation of the Myocyte Enhancer Factor 2Cα1 Splice Variant Promotes Skeletal Muscle Regeneration and Hypertrophy.

    PubMed

    Baruffaldi, Fiorenza; Montarras, Didier; Basile, Valentina; De Feo, Luca; Badodi, Sara; Ganassi, Massimo; Battini, Renata; Nicoletti, Carmine; Imbriano, Carol; Musarò, Antonio; Molinari, Susanna

    2017-03-01

    The transcription factor MEF2C (Myocyte Enhancer Factor 2C) plays an established role in the early steps of myogenic differentiation. However, the involvement of MEF2C in adult myogenesis and in muscle regeneration has not yet been systematically investigated. Alternative splicing of mammalian MEF2C transcripts gives rise to two mutually exclusive protein variants: MEF2Cα2 which exerts a positive control of myogenic differentiation, and MEF2Cα1, in which the α1 domain acts as trans-repressor of the MEF2C pro-differentiation activity itself. However, MEF2Cα1 variants are persistently expressed in differentiating cultured myocytes, suggesting a role in adult myogenesis. We found that overexpression of both MEF2Cα1/α2 proteins in a mouse model of muscle injury promotes muscle regeneration and hypertrophy, with each isoform promoting different stages of myogenesis. Besides the ability of MEF2Cα2 to increase differentiation, we found that overexpressed MEF2Cα1 enhances both proliferation and differentiation of primary myoblasts, and activates the AKT/mTOR/S6K anabolic signaling pathway in newly formed myofibers. The multiple activities of MEF2Cα1 are modulated by phosphorylation of Ser98 and Ser110, two amino acid residues located in the α1 domain of MEF2Cα1. These specific phosphorylations allow the interaction of MEF2Cα1 with the peptidyl-prolyl isomerase PIN1, a regulator of MEF2C functions. Overall, in this study we established a novel regulatory mechanism in which the expression and the phosphorylation of MEF2Cα1 are critically required to sustain the adult myogenesis. The described molecular mechanism will represent a new potential target for the development of therapeutical strategies to treat muscle-wasting diseases. Stem Cells 2017;35:725-738.

  13. Tyrosinase overexpression promotes ATM-dependent p53 phosphorylation by quercetin and sensitizes melanoma cells to dacarbazine.

    PubMed

    Thangasamy, Thilakavathy; Sittadjody, Sivanandane; Limesand, Kirsten H; Burd, Randy

    2008-01-01

    Dacarbazine (DTIC) has been used for the treatment of melanoma for decades. However, monotherapy with this chemotherapeutic agent results only in moderate response rates. To improve tumor response to DTIC current clinical trials in melanoma focus on combining a novel targeted agent with chemotherapy. Here, we demonstrate that tyrosinase which is commonly overexpressed in melanoma activates the bioflavonoid quercetin (Qct) and promotes an ataxia telangiectasia mutated (ATM)-dependent DNA damage response. This response sensitizes melanoma cells that overexpress tyrosinase to DTIC. In DB-1 melanoma cells that overexpress tyrosinase (Tyr(+) cells), the threshold for phosphorylation of ATM and p53 at serine 15 was observed at a low dose of Qct (25 microM) when compared to the mock transfected pcDNA3 cells, which required a higher dose (75 microM). Both pcDNA3 and Tyr(+) DB-1 cells demonstrated similar increases in phosphorylation of p53 at other serine sites, but in the Tyr(+) cells, DNApk expression was found to be reduced compared to control cells, indicating a shift towards an ATM-mediated response. The DB-1 control cells were resistant to DTIC, but were sensitized to apoptosis with high dose Qct, while Tyr(+) cells were sensitized to DTIC with low or high dose Qct. Qct also sensitized SK Mel 5 (p53 wildtype) and 28 (p53 mutant) cells to DTIC. However, when SK Mel 5 cells were transiently transfected with tyrosinase and treated with Qct plus DTIC, SK Mel 5 cells demonstrated a more than additive induction of apoptosis. Therefore, this study demonstrates that tyrosinase overexpression promotes an ATM-dependent p53 phosphorylation by Qct treatment and sensitizes melanoma cells to dacarbazine. In conclusion, these results suggest that Qct or Qct analogues may significantly improve DTIC response rates in tumors that express tyrosinase.

  14. 8-Prenylnaringenin promotes recovery from immobilization-induced disuse muscle atrophy through activation of the Akt phosphorylation pathway in mice.

    PubMed

    Mukai, Rie; Horikawa, Hitomi; Lin, Pei-Yi; Tsukumo, Nao; Nikawa, Takeshi; Kawamura, Tomoyuki; Nemoto, Hisao; Terao, Junji

    2016-12-01

    8-Prenylnaringenin (8-PN) is a prenylflavonoid that originates from hop extracts and is thought to help prevent disuse muscle atrophy. We hypothesized that 8-PN affects muscle plasticity by promoting muscle recovery under disuse muscle atrophy. To test the promoting effect of 8-PN on muscle recovery, we administered an 8-PN mixed diet to mice that had been immobilized with a cast to one leg for 14 days. Intake of the 8-PN mixed diet accelerated recovery from muscle atrophy, and prevented reductions in Akt phosphorylation. Studies on cell cultures of mouse myotubes in vitro demonstrated that 8-PN activated the PI3K/Akt/P70S6K1 pathway at physiological concentrations. A cell-culture study using an inhibitor of estrogen receptors and an in vivo experiment with ovariectomized mice suggested that the estrogenic activity of 8-PN contributed to recovery from disuse muscle atrophy through activation of an Akt phosphorylation pathway. These data strongly suggest that 8-PN is a naturally occurring compound that could be used as a nutritional supplement to aid recovery from disuse muscle atrophy. Copyright © 2016 the American Physiological Society.

  15. Extended Resections for Hilar Cholangiocarcinoma

    PubMed Central

    Neuhaus, Peter; Jonas, Sven; Bechstein, Wolf O.; Lohmann, Rüdiger; Radke, Cornelia; Kling, Norbert; Wex, Cora; Lobeck, Hartmut; Hintze, Rainer

    1999-01-01

    Objective To evaluate different strategies for extended resections of hilar cholangiocarcinomas on radicality and survival. Summary Background Data Surgical resection of hilar cholangiocarcinoma is the only potentially curative treatment. Resection of central bile duct carcinomas, however, cannot always comply with the general principles of surgical oncology to achieve wide tumor-free margins with no-touch techniques. Methods From 1988 to 1998, 95 patients underwent resection of hilar cholangiocarcinoma. Eighty patients had hilar and hepatic resections and 15 had liver transplantation and partial pancreatoduodenectomy (LTPP;i.e., eradication of the entire biliary tract using a no-touch technique). Results The 60-day death rate was 8%. The overall 1- and 5-year survival rates were 67% and 22%, respectively. Five-year survival rates after R0, R1, and R2 resections were 37%, 9%, and 0%. In a multivariate analysis, surgical radicality was the strongest determinant of survival (p < 0.001). The rate of formally curative resection (R0 resection) was significantly lower in hilar resections (29%) than in liver resections (left hemihepatectomy 59%, right hemihepatectomy 55%, right trisegmentectomy 65%; p < 0.05). The highest rate of R0 resection was observed after LTPP (93%; p < 0.05). Right trisegmentectomies achieved the highest rate of 5-year survival after R0 resection (57%). In a multivariate analysis of patient survival after R0 resection, additional portal vein resection was the only significant factor. The 5-year survival rate after formally curative liver resection with portal vein resection was 65%versus 28% without. Conclusion Extended resections, especially right trisegmentectomies and LTPP, resulted in the highest rate of R0 resection. Right trisegmentectomy together with portal vein resection best represents the principles of surgical oncology and may be regarded as the surgical procedure of choice. Immunosuppression limits the applicability of LTPP. PMID

  16. HIPK2 sustains apoptotic response by phosphorylating Che-1/AATF and promoting its degradation

    PubMed Central

    De Nicola, F; Catena, V; Rinaldo, C; Bruno, T; Iezzi, S; Sorino, C; Desantis, A; Camerini, S; Crescenzi, M; Floridi, A; Passananti, C; Soddu, S; Fanciulli, M

    2014-01-01

    Che-1/AATF is an RNA polymerase II-binding protein that is involved in the regulation of gene transcription, which undergoes stabilization and accumulation in response to DNA damage. We have previously demonstrated that following apoptotic induction, Che-1 protein levels are downregulated through its interaction with the E3 ligase HDM2, which leads to Che-1 degradation by ubiquitylation. This interaction is mediated by Pin1, which determines a phosphorylation-dependent conformational change. Here we demonstrate that HIPK2, a proapoptotic kinase, is involved in Che-1 degradation. HIPK2 interacts with Che-1 and, upon genotoxic stress, phosphorylates it at specific residues. This event strongly increases HDM2/Che-1 interaction and degradation of Che-1 protein via ubiquitin-dependent proteasomal system. In agreement with these findings, we found that HIPK2 depletion strongly decreases Che-1 ubiquitylation and degradation. Notably, Che-1 overexpression strongly counteracts HIPK2-induced apoptosis. Our results establish Che-1 as a new HIPK2 target and confirm its important role in the cellular response to DNA damage. PMID:25210797

  17. Erythropoietin and carbamylated erythropoietin promote histone deacetylase 5 phosphorylation and nuclear export in rat hippocampal neurons

    SciTech Connect

    Jo, Hye-Ryeong; Kim, Yong-Seok; Son, Hyeon

    2016-01-29

    Erythropoietin (EPO) produces neurotrophic effects in animal model of neurodegeneration. However, clinical use of EPO is limited due to thrombotic risk. Carbamylated EPO (cEPO), devoid of thrombotic risk, has been proposed as a novel neuroprotective and neurotrophic agent although the molecular mechanisms of cEPO remain incomplete. Here, we show a previously unidentified role of histone deacetylase 5 (HDAC5) in the actions of EPO and cEPO. EPO and cEPO regulate the HDAC5 phosphorylation at two critical sites, Ser259 and Ser498 through a protein kinase D (PKD) dependent pathway. In addition, EPO and cEPO rapidly stimulates nuclear export of HDAC5 in rat hippocampal neurons which expressing HDAC5-GFP. Consequently, EPO and cEPO enhanced the myocyte enhancer factor-2 (MEF2) target gene expression. Taken together, our results reveal that EPO and cEPO mediate MEF2 target gene expression via the regulation of HDAC5 phosphorylation at Ser259/498, and suggest that HDAC5 could be a potential mechanism contributing to the therapeutic actions of EPO and cEPO.

  18. PKA phosphorylation redirects ERα to promoters of a unique gene set to induce tamoxifen resistance.

    PubMed

    de Leeuw, R; Flach, K; Bentin Toaldo, C; Alexi, X; Canisius, S; Neefjes, J; Michalides, R; Zwart, W

    2013-07-25

    Protein kinase A (PKA)-induced estrogen receptor alpha (ERα) phosphorylation at serine residue 305 (ERαS305-P) can induce tamoxifen (TAM) resistance in breast cancer. How this phospho-modification affects ERα specificity and translates into TAM resistance is unclear. Here, we show that S305-P modification of ERα reprograms the receptor, redirecting it to new transcriptional start sites, thus modulating the transcriptome. By altering the chromatin-binding pattern, Ser305 phosphorylation of ERα translates into a 26-gene expression classifier that identifies breast cancer patients with a poor disease outcome after TAM treatment. MYC-target genes and networks were significantly enriched in this gene classifier that includes a number of selective targets for ERαS305-P. The enhanced expression of MYC increased cell proliferation in the presence of TAM. We demonstrate that activation of the PKA signaling pathway alters the transcriptome by redirecting ERα to new transcriptional start sites, resulting in altered transcription and TAM resistance.

  19. EGFR-induced phosphorylation of type Iγ phosphatidylinositol phosphate kinase promotes pancreatic cancer progression

    PubMed Central

    Xue, Junli; Xiong, Xunhao; Huang, Yan; Hu, Jinghua; Ling, Kun

    2017-01-01

    Pancreatic cancer is one of the deadliest malignancies and effective treatment has always been lacking. In current study, we investigated how the type Iγ phosphatidylinositol phosphate kinase (PIPKIγ) participates in the progression of pancreatic ductal adenocarcinoma (PDAC) for novel therapeutic potentials against this lethal disease. We found that PIPKIγ is up-regulated in all tested PDAC cell lines. The growth factor (including EGFR)-induced tyrosine phosphorylation of PIPKIγ is significantly elevated in in situ and metastatic PDAC tissues. Loss of PIPKIγ inhibits the aggressiveness of PDAC cells by restraining the activities of AKT and STAT3, as well as MT1-MMP expression. Therefore when planted into the pancreas of nude mice, PIPKIγ-depleted PDAC cells exhibits substantially repressed tumor growth and metastasis comparing to control PDAC cells. Results from further studies showed that the phosphorylation-deficient PIPKIγ mutant, unlike its wild-type counterpart, cannot rescue PDAC progression inhibited by PIPKIγ depletion. These findings indicate that PIPKIγ, functioning downstream of EGFR signaling, is critical to the progression of PDAC, and suggest that PIPKIγ is potentially a valuable therapeutic target for PDAC treatment. PMID:28388589

  20. Dpr Acts as a molecular switch, inhibiting Wnt signaling when unphosphorylated, but promoting Wnt signaling when phosphorylated by casein kinase Idelta/epsilon.

    PubMed

    Teran, Evelyn; Branscomb, Aron D; Seeling, Joni M

    2009-01-01

    The Wnt pathway is a key regulator of development and tumorigenesis. Dpr (Dact/Frodo) influences Wnt signaling in part through the interaction of its PDZ-B domain with Dsh's PDZ domain. Studies have shown that XDpr1a and its close relative, Frodo, are involved in multiple steps of the Wnt pathway in either inhibitory or activating roles. We found that XDpr1a is phosphorylated by casein kinase Idelta/epsilon (CKIdelta/epsilon), an activator of Wnt signaling, in the presence of XDsh. Abrogating XDpr1a's ability to bind XDsh through mutation of XDpr1a's PDZ-B domain blocks CK1delta/epsilon's phosphorylation of XDpr1a. Conversely, XDsh possessing a mutation in its PDZ domain that is unable to bind XDpr1a does not promote XDpr1a phosphorylation. Phosphorylation of XDpr1a and XDsh by CKIdelta/epsilon decreases their interaction. Moreover, the phosphorylation of XDpr1a by CKIdelta/epsilon not only abrogates XDpr1a's promotion of beta-catenin degradation but blocks beta-catenin degradation. Our data suggest that XDpr1a phosphorylation by CKIdelta/epsilon is dependent on the interaction of XDpr1a's PDZ-B domain with XDsh's PDZ domain, and that the phosphorylation state of XDpr1a determines whether it inhibits or activates Wnt signaling.

  1. Dpr Acts as a Molecular Switch, Inhibiting Wnt Signaling when Unphosphorylated, but Promoting Wnt Signaling when Phosphorylated by Casein Kinase Iδ/ε

    PubMed Central

    Teran, Evelyn; Branscomb, Aron D.; Seeling, Joni M.

    2009-01-01

    The Wnt pathway is a key regulator of development and tumorigenesis. Dpr (Dact/Frodo) influences Wnt signaling in part through the interaction of its PDZ-B domain with Dsh's PDZ domain. Studies have shown that XDpr1a and its close relative, Frodo, are involved in multiple steps of the Wnt pathway in either inhibitory or activating roles. We found that XDpr1a is phosphorylated by casein kinase Iδ/ε (CKIδ/ε), an activator of Wnt signaling, in the presence of XDsh. Abrogating XDpr1a's ability to bind XDsh through mutation of XDpr1a's PDZ-B domain blocks CK1δ/ε's phosphorylation of XDpr1a. Conversely, XDsh possessing a mutation in its PDZ domain that is unable to bind XDpr1a does not promote XDpr1a phosphorylation. Phosphorylation of XDpr1a and XDsh by CKIδ/ε decreases their interaction. Moreover, the phosphorylation of XDpr1a by CKIδ/ε not only abrogates XDpr1a's promotion of β-catenin degradation but blocks β-catenin degradation. Our data suggest that XDpr1a phosphorylation by CKIδ/ε is dependent on the interaction of XDpr1a's PDZ-B domain with XDsh's PDZ domain, and that the phosphorylation state of XDpr1a determines whether it inhibits or activates Wnt signaling. PMID:19440376

  2. Orchestrated Action of PP2A Antagonizes Atg13 Phosphorylation and Promotes Autophagy after the Inactivation of TORC1

    PubMed Central

    Kondo, Akihiro; Kaneko, Atsuki; Koike, Naoki; Ushimaru, Takashi

    2016-01-01

    Target of rapamycin complex 1 (TORC1) phosphorylates autophagy-related Atg13 and represses autophagy under nutrient-rich conditions. However, when TORC1 becomes inactive upon nutrient depletion or treatment with the TORC1 inhibitor rapamycin, Atg13 dephosphorylation occurs rapidly, and autophagy is induced. At present, the phosphatases involved in Atg13 dephosphorylation remain unknown. Here, we show that two protein phosphatase 2A (PP2A) phosphatases, PP2A-Cdc55 and PP2A-Rts1, which are activated by inactivation of TORC1, are required for sufficient Atg13 dephosphorylation and autophagy induction after TORC1 inactivation in budding yeast. After rapamycin treatment, dephosphorylation of Atg13, activation of Atg1 kinase, pre-autophagosomal structure (PAS) formation and autophagy induction are all impaired in PP2A-deleted cells. Conversely, overexpression of non-phosphorylatable Atg13 suppressed defects in autophagy in PP2A mutant. This study revealed that the orchestrated action of PP2A antagonizes Atg13 phosphorylation and promotes autophagy after the inactivation of TORC1. PMID:27973551

  3. Cdk1 phosphorylates the Rac activator Tiam1 to activate centrosomal Pak and promote mitotic spindle formation

    PubMed Central

    Whalley, Helen J.; Porter, Andrew P.; Diamantopoulou, Zoi; White, Gavin R. M.; Castañeda-Saucedo, Eduardo; Malliri, Angeliki

    2015-01-01

    Centrosome separation is critical for bipolar spindle formation and the accurate segregation of chromosomes during mammalian cell mitosis. Kinesin-5 (Eg5) is a microtubule motor essential for centrosome separation, and Tiam1 and its substrate Rac antagonize Eg5-dependent centrosome separation in early mitosis promoting efficient chromosome congression. Here we identify S1466 of Tiam1 as a novel Cdk1 site whose phosphorylation is required for the mitotic function of Tiam1. We find that this phosphorylation of Tiam1 is required for the activation of group I p21-activated kinases (Paks) on centrosomes in prophase. Further, we show that both Pak1 and Pak2 counteract centrosome separation in a kinase-dependent manner and demonstrate that they act downstream of Tiam1. We also show that depletion of Pak1/2 allows cells to escape monopolar arrest by Eg5 inhibition, highlighting the potential importance of this signalling pathway for the development of Eg5 inhibitors as cancer therapeutics. PMID:26078008

  4. Cdk1 phosphorylates the Rac activator Tiam1 to activate centrosomal Pak and promote mitotic spindle formation.

    PubMed

    Whalley, Helen J; Porter, Andrew P; Diamantopoulou, Zoi; White, Gavin R M; Castañeda-Saucedo, Eduardo; Malliri, Angeliki

    2015-06-16

    Centrosome separation is critical for bipolar spindle formation and the accurate segregation of chromosomes during mammalian cell mitosis. Kinesin-5 (Eg5) is a microtubule motor essential for centrosome separation, and Tiam1 and its substrate Rac antagonize Eg5-dependent centrosome separation in early mitosis promoting efficient chromosome congression. Here we identify S1466 of Tiam1 as a novel Cdk1 site whose phosphorylation is required for the mitotic function of Tiam1. We find that this phosphorylation of Tiam1 is required for the activation of group I p21-activated kinases (Paks) on centrosomes in prophase. Further, we show that both Pak1 and Pak2 counteract centrosome separation in a kinase-dependent manner and demonstrate that they act downstream of Tiam1. We also show that depletion of Pak1/2 allows cells to escape monopolar arrest by Eg5 inhibition, highlighting the potential importance of this signalling pathway for the development of Eg5 inhibitors as cancer therapeutics.

  5. Phosphorylation by Akt1 Promotes Skp2 Cytoplasmic Localization and Impairs APC/Cdh1-mediated Skp2 Destruction

    PubMed Central

    Gao, Daming; Inuzuka, Hiroyuki; Tseng, Alan; Chin, Rebecca Y.; Toker, Alex; Wei, Wenyi

    2010-01-01

    Deregulated Skp2 function promotes cell transformation, and this is consistent with observations of Skp2 over-expression in many human cancers. However, the mechanisms underlying elevated Skp2 expression remain elusive. Here we report that the serine/threonine protein kinase Akt1, but not Akt2, directly controls Skp2 stability by a mechanism that involves degradation by the APC/Cdh1 ubiquitin ligase complex. We further show that Akt1 phosphorylates Skp2 at Ser72, which is required to disrupt the interaction between Cdh1 and Skp2. In addition, we show that Ser72 is localized within a putative Nuclear Localization Sequence (NLS) and that phosphorylation of Ser72 by Akt leads to Skp2 cytoplasmic translocation. This finding expands our knowledge of how specific signaling kinase cascades influence proteolysis governed by APC/Cdh1 complexes, and provides evidence that elevated Akt activity and cytoplasmic Skp2 expression may be causative for cancer progression. PMID:19270695

  6. Phosphorylation of BRN2 Modulates Its Interaction with the Pax3 Promoter To Control Melanocyte Migration and Proliferation

    PubMed Central

    Berlin, Irina; Denat, Laurence; Steunou, Anne-Lise; Puig, Isabel; Champeval, Delphine; Colombo, Sophie; Roberts, Karen; Bonvin, Elise; Bourgeois, Yveline; Davidson, Irwin; Delmas, Véronique; Nieto, Laurence; Goding, Colin R.

    2012-01-01

    MITF-M and PAX3 are proteins central to the establishment and transformation of the melanocyte lineage. They control various cellular mechanisms, including migration and proliferation. BRN2 is a POU domain transcription factor expressed in melanoma cell lines and is involved in proliferation and invasion, at least in part by regulating the expression of MITF-M and PAX3. The T361 and S362 residues of BRN2, both in the POU domain, are conserved throughout the POU protein family and are targets for phosphorylation, but their roles in vivo remain unknown. To examine the role of this phosphorylation, we generated mutant BRN2 in which these two residues were replaced with alanines (BRN2TS→BRN2AA). When expressed in melanocytes in vitro or in the melanocyte lineage in transgenic mice, BRN2TS induced proliferation and repressed migration, whereas BRN2AA repressed both proliferation and migration. BRN2TS and BRN2AA bound and repressed the MITF-M promoter, whereas PAX3 transcription was induced by BRN2TS but repressed by BRN2AA. Expression of the BRN2AA transgene in a Mitf heterozygous background and in a Pax3 mutant background enhanced the coat color phenotype. Our findings show that melanocyte migration and proliferation are controlled both through the regulation of PAX3 by nonphosphorylated BRN2 and through the regulation of MITF-M by the overall BRN2 level. PMID:22290434

  7. The Pch2 AAA+ ATPase promotes phosphorylation of the Hop1 meiotic checkpoint adaptor in response to synaptonemal complex defects

    PubMed Central

    Herruzo, Esther; Ontoso, David; González-Arranz, Sara; Cavero, Santiago; Lechuga, Ana; San-Segundo, Pedro A.

    2016-01-01

    Meiotic cells possess surveillance mechanisms that monitor critical events such as recombination and chromosome synapsis. Meiotic defects resulting from the absence of the synaptonemal complex component Zip1 activate a meiosis-specific checkpoint network resulting in delayed or arrested meiotic progression. Pch2 is an evolutionarily conserved AAA+ ATPase required for the checkpoint-induced meiotic block in the zip1 mutant, where Pch2 is only detectable at the ribosomal DNA array (nucleolus). We describe here that high levels of the Hop1 protein, a checkpoint adaptor that localizes to chromosome axes, suppress the checkpoint defect of a zip1 pch2 mutant restoring Mek1 activity and meiotic cell cycle delay. We demonstrate that the critical role of Pch2 in this synapsis checkpoint is to sustain Mec1-dependent phosphorylation of Hop1 at threonine 318. We also show that the ATPase activity of Pch2 is essential for its checkpoint function and that ATP binding to Pch2 is required for its localization. Previous work has shown that Pch2 negatively regulates Hop1 chromosome abundance during unchallenged meiosis. Based on our results, we propose that, under checkpoint-inducing conditions, Pch2 also possesses a positive action on Hop1 promoting its phosphorylation and its proper distribution on unsynapsed chromosome axes. PMID:27257060

  8. Phosphorylation promotes neurotoxicity in a C. elegans model of TDP-43 proteinopathy

    PubMed Central

    Liachko, Nicole F.; Guthrie, Chris R.; Kraemer, Brian C.

    2010-01-01

    Neurodegenerative disorders characterized by neuronal and glial lesions containing aggregated pathological TDP-43 protein in the cytoplasm, nucleus, or neurites are collectively referred to as TDP-43 proteinopathies. Lesions containing aggregated TDP-43 protein are a hallmark of amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration with ubiquitinated inclusions (FTLD-U). In addition, mutations in human TDP-43 cause ALS. We have developed a C. elegans model of TDP-43 proteinopathies to study the cellular, molecular, and genetic underpinnings of TDP-43 mediated neurotoxicity. Expression of normal human TDP-43 in all C. elegans neurons causes moderate motor defects, while ALS-mutant G290A, A315T, or M337V TDP-43 transgenes cause severe motor dysfunction. The model recapitulates some characteristic features of ALS and FTLD-U including age-induced decline in motor function, decreased lifespan, and degeneration of motor neurons accompanied by hyperphosphorylation, truncation, and ubiquitination of TDP-43 protein that accumulates in detergent insoluble protein deposits. In C. elegans, TDP-43 neurotoxicity is independent of activity of the cell death caspase CED-3. Furthermore, phosphorylation of TDP-43 at serine residues 409/410 drives mutant TDP-43 toxicity. This model provides a tractable system for further dissection of the cellular and molecular mechanisms underlying TDP-43 neuropathology. PMID:21123567

  9. CaMKII regulates proteasome phosphorylation and activity and promotes memory destabilization following retrieval.

    PubMed

    Jarome, Timothy J; Ferrara, Nicole C; Kwapis, Janine L; Helmstetter, Fred J

    2016-02-01

    Numerous studies have suggested that memories "destabilize" and require de novo protein synthesis in order to reconsolidate following retrieval, but very little is known about how this destabilization process is regulated. Recently, ubiquitin-proteasome mediated protein degradation has been identified as a critical regulator of memory trace destabilization following retrieval, though the specific mechanisms controlling retrieval-induced changes in ubiquitin-proteasome activity remain equivocal. Here, we found that proteasome activity is increased in the amygdala in a CaMKII-dependent manner following the retrieval of a contextual fear memory. We show that in vitro inhibition of CaMKII reversed retrieval-induced increases in proteasome activity. Additionally, in vivo pharmacological blockade of CaMKII abolished increases in proteolytic activity and activity related regulatory phosphorylation in the amygdala following retrieval, suggesting that CaMKII was "upstream" of protein degradation during the memory reconsolidation process. Consistent with this, while inhibiting CaMKII in the amygdala did not impair memory following retrieval, it completely attenuated the memory impairments that resulted from post-retrieval protein synthesis blockade. Collectively, these results suggest that CaMKII controls the initiation of the memory reconsolidation process through regulation of the proteasome.

  10. Administration of Additional Phosphorylated Prolactin During Pregnancy Inhibits Mammary Ductal Branching and Promotes Premature Lobuloalveolus Development

    DTIC Science & Technology

    2002-07-01

    promotes differentiation. Further, we have demonstrated that these effects of U-PRL and S179D PRL are produced directly on the mammary gland. In...addition, we have been able to show that U-PRL and S179D PRL exert these very different effects by changing the balance of signaling between the two major

  11. ATP counteracts the rundown of gap junctional channels of rat ventricular myocytes by promoting protein phosphorylation.

    PubMed

    Verrecchia, F; Duthe, F; Duval, S; Duchatelle, I; Sarrouilhe, D; Herve, J C

    1999-04-15

    1. The degree of cell-to-cell coupling between ventricular myocytes of neonatal rats appeared well preserved when studied in the perforated version of the patch clamp technique or, in double whole-cell conditions, when ATP was present in the patch pipette solution. In contrast, when ATP was omitted, the amplitude of junctional current rapidly declined (rundown). 2. To examine the mechanism(s) of ATP action, an 'internal perfusion technique' was adapted to dual patch clamp conditions, and reintroduction of ATP partially reversed the rundown of junctional channels. 3. Cell-to-cell communication was not preserved by a non-hydrolysable ATP analogue (5'-adenylimidodiphosphate, AMP-PNP), indicating that the effect most probably did not involve direct interaction of ATP with the channel-forming proteins. 4. An ATP analogue supporting protein phosphorylation but not active transport processes (adenosine 5'-O-(3-thiotriphosphate), ATPgammaS) maintained normal intercellular communication, suggesting that the effect was due to kinase activity rather than to altered intracellular Ca2+. 5. A broad spectrum inhibitor of endogenous serine/threonine protein kinases (H7) reversibly reduced the intercellular coupling. A non-specific exogenous protein phosphatase (alkaline phosphatase) mimicked the effects of ATP deprivation. The non-specific inhibition of endogenous protein phosphatases resulted in the preservation of substantial cell-to-cell communication in ATP-free conditions. 6. The activity of gap junctional channels appears to require both the presence of ATP and protein kinase activity to counteract the tonic activity of endogenous phosphatase(s).

  12. Mitochondrial Localized Stat3 Promotes Breast Cancer Growth via Phosphorylation of Serine 727*

    PubMed Central

    Zhang, Qifang; Raje, Vidisha; Yakovlev, Vasily A.; Yacoub, Adly; Szczepanek, Karol; Meier, Jeremy; Derecka, Marta; Chen, Qun; Hu, Ying; Sisler, Jennifer; Hamed, Hossein; Lesnefsky, Edward J.; Valerie, Kristoffer; Dent, Paul; Larner, Andrew C.

    2013-01-01

    Signal transducer and activator of transcription 3 (Stat3) is a key mediator in the development of many cancers. For 20 years, it has been assumed that Stat3 mediates its biological activities as a nuclear localized transcription factor activated by many cytokines. However, recent studies from this laboratory and others indicate that Stat3 has an independent function in the mitochondria (mitoStat3) where it controls the activity of the electron transport chain (ETC) and mediates Ras-induced transformation of mouse embryo fibroblasts. The actions of mitoStat3 in controlling respiration and Ras transformation are mediated by the phosphorylation state of serine 727. To address the role of mitoStat3 in the pathogenesis of cells that are transformed, we used 4T1 breast cancer cells, which form tumors that metastasize in immunocompetent mice. Substitution of Ser-727 for an alanine or aspartate in Stat3 that has a mitochondrial localization sequence, MLS-Stat3, has profound effects on tumor growth, complex I activity of the ETC, and accumulation of reactive oxygen species (ROS). Cells expressing MLS-Stat3(S727A) display slower tumor growth, decreased complex I activity of the ETC, and increased ROS accumulation under hypoxia compared with cells expressing MLS-Stat3. In contrast, cells expressing MLS-Stat3(S727D) show enhanced tumor growth and complex I activity and decreased production of ROS. These results highlight the importance of serine 727 of mitoStat3 in breast cancer and suggest a novel role for mitoStat3 in regulation of ROS concentrations through its action on the ETC. PMID:24019511

  13. Pathogenesis, Diagnosis, and Management of Cholangiocarcinoma

    PubMed Central

    Rizvi, Sumera; Gores, Gregory J.

    2013-01-01

    Cholangiocarcinomas (CCAs) are hepatobiliary cancers with features of cholangiocyte differentiation; they can be classified anatomically as intrahepatic (iCCA), perihilar (pCCA), or distal CCA (dCCA). These subtypes differ not only in their anatomic location but in epidemiology, origin, etiology, pathogenesis, and treatment. The incidence and mortality of iCCA has been increasing over the past 3 decades, and only a low percentage of patients survive until 5 y after diagnosis. Geographic variations in the incidence of CCA are related to variations in risk factors. Changes in oncogene and inflammatory signaling pathways, as well as genetic and epigenetic alterations and chromosome aberrations, have been shown to contribute to development of CCA. Furthermore, CCAs are surrounded by a dense stroma that contains many cancer-associated fibroblasts, which promotes their progression. We have gained a better understanding of the imaging characteristics of iCCAs and have developed advanced cytologic techniques to detect pCCAs. Patients with iCCAs are usually treated surgically, whereas liver transplantation following neoadjuvant chemoradiation is an option for a subset of patients with pCCAs. We review recent developments in our understanding of the epidemiology, pathogenesis, of CCA, along with advances in classification, diagnosis and treatment. PMID:24140396

  14. Sodium Butyrate Promotes Reassembly of Tight Junctions in Caco-2 Monolayers Involving Inhibition of MLCK/MLC2 Pathway and Phosphorylation of PKCβ2.

    PubMed

    Miao, Wei; Wu, Xiujuan; Wang, Kang; Wang, Wenjing; Wang, Yumei; Li, Zhigang; Liu, Jingjing; Li, Li; Peng, Luying

    2016-10-10

    As a physiological small molecular product from the microbial fermentation of dietary fibers, butyrate plays an important role in maintaining intestinal health. Our previous works have proved that the effect of sodium butyrate (NaB) on the intestinal barrier function is mediated by activation of AMP-activated protein kinase (AMPK). However, the detailed pathway involved remains unknown. Using the calcium switch assay in the Caco-2 cell monolayer model, we found here that NaB activated AMPK mainly by increasing the calcium level, but not the ATP concentration, via promoting store-operated calcium entry (SOCE). Upon the activation of AMPK, NaB promoted the reassembly of tight junctions (TJs) based on reducing the phosphorylation of myosin II regulatory light chain (MLC2) at Ser19 and increasing phosphorylation of protein kinase C β2 (PKCβ2) at Ser660. Inhibiting (protein kinase C β) PKCβ blocked the reassembly of TJs induced by NaB in the barrier monolayer model. These results indicated that NaB could activate the calcium/calmodulin-dependent protein kinase kinase β (CaMKKβ) pathway to mediate AMPK phosphorylating, which then inhibited the phosphorylation of MLC2 and promoted the phosphorylation of PKCβ2, respectively, so that the downstream molecules of AMPK coordinately contributed to the reassembly of TJs in the Caco-2 barrier model. These results suggested a potential mechanism of butyrate for intestine homeostasis and protection.

  15. Sodium Butyrate Promotes Reassembly of Tight Junctions in Caco-2 Monolayers Involving Inhibition of MLCK/MLC2 Pathway and Phosphorylation of PKCβ2

    PubMed Central

    Miao, Wei; Wu, Xiujuan; Wang, Kang; Wang, Wenjing; Wang, Yumei; Li, Zhigang; Liu, Jingjing; Li, Li; Peng, Luying

    2016-01-01

    As a physiological small molecular product from the microbial fermentation of dietary fibers, butyrate plays an important role in maintaining intestinal health. Our previous works have proved that the effect of sodium butyrate (NaB) on the intestinal barrier function is mediated by activation of AMP-activated protein kinase (AMPK). However, the detailed pathway involved remains unknown. Using the calcium switch assay in the Caco-2 cell monolayer model, we found here that NaB activated AMPK mainly by increasing the calcium level, but not the ATP concentration, via promoting store-operated calcium entry (SOCE). Upon the activation of AMPK, NaB promoted the reassembly of tight junctions (TJs) based on reducing the phosphorylation of myosin II regulatory light chain (MLC2) at Ser19 and increasing phosphorylation of protein kinase C β2 (PKCβ2) at Ser660. Inhibiting (protein kinase C β) PKCβ blocked the reassembly of TJs induced by NaB in the barrier monolayer model. These results indicated that NaB could activate the calcium/calmodulin-dependent protein kinase kinase β (CaMKKβ) pathway to mediate AMPK phosphorylating, which then inhibited the phosphorylation of MLC2 and promoted the phosphorylation of PKCβ2, respectively, so that the downstream molecules of AMPK coordinately contributed to the reassembly of TJs in the Caco-2 barrier model. These results suggested a potential mechanism of butyrate for intestine homeostasis and protection. PMID:27735862

  16. The FGFR4-G388R polymorphism promotes mitochondrial STAT3 serine phosphorylation to facilitate pituitary growth hormone cell tumorigenesis.

    PubMed

    Tateno, Toru; Asa, Sylvia L; Zheng, Lei; Mayr, Thomas; Ullrich, Axel; Ezzat, Shereen

    2011-12-01

    Pituitary tumors are common intracranial neoplasms, yet few germline abnormalities have been implicated in their pathogenesis. Here we show that a single nucleotide germline polymorphism (SNP) substituting an arginine (R) for glycine (G) in the FGFR4 transmembrane domain can alter pituitary cell growth and hormone production. Compared with FGFR4-G388 mammosomatotroph cells that support prolactin (PRL) production, FGFR4-R388 cells express predominantly growth hormone (GH). Growth promoting effects of FGFR4-R388 as evidenced by enhanced colony formation was ascribed to Src activation and mitochondrial serine phosphorylation of STAT3 (pS-STAT3). In contrast, diminished pY-STAT3 mediated by FGFR4-R388 relieved GH inhibition leading to hormone excess. Using a knock-in mouse model, we demonstrate the ability of FGFR4-R385 to promote GH pituitary tumorigenesis. In patients with acromegaly, pituitary tumor size correlated with hormone excess in the presence of the FGFR4-R388 but not the FGFR4-G388 allele. Our findings establish a new role for the FGFR4-G388R polymorphism in pituitary oncogenesis, providing a rationale for targeting Src and STAT3 in the personalized treatment of associated disorders.

  17. Phosphorylation-triggered CUEDC2 degradation promotes UV-induced G1 arrest through APC/C(Cdh1) regulation.

    PubMed

    Zhang, Wei-Na; Zhou, Jie; Zhou, Tao; Li, Ai-Ling; Wang, Na; Xu, Jin-Jing; Chang, Yan; Man, Jiang-Hong; Pan, Xin; Li, Tao; Li, Wei-Hua; Mu, Rui; Liang, Bing; Chen, Liang; Jin, Bao-Feng; Xia, Qing; Gong, Wei-Li; Zhang, Xue-Min; Wang, Li; Li, Hui-Yan

    2013-07-02

    DNA damage triggers cell cycle arrest to provide a time window for DNA repair. Failure of arrest could lead to genomic instability and tumorigenesis. DNA damage-induced G1 arrest is generally achieved by the accumulation of Cyclin-dependent kinase inhibitor 1 (p21). However, p21 is degraded and does not play a role in UV-induced G1 arrest. The mechanism of UV-induced G1 arrest thus remains elusive. Here, we have identified a critical role for CUE domain-containing protein 2 (CUEDC2) in this process. CUEDC2 binds to and inhibits anaphase-promoting complex/cyclosome-Cdh1 (APC/C(Cdh1)), a critical ubiquitin ligase in G1 phase, thereby stabilizing Cyclin A and promoting G1-S transition. In response to UV irradiation, CUEDC2 undergoes ERK1/2-dependent phosphorylation and ubiquitin-dependent degradation, leading to APC/C(Cdh1)-mediated Cyclin A destruction, Cyclin-dependent kinase 2 inactivation, and G1 arrest. A nonphosphorylatable CUEDC2 mutant is resistant to UV-induced degradation. Expression of this stable mutant effectively overrides UV-induced G1-S block. These results establish CUEDC2 as an APC/C(Cdh1) inhibitor and indicate that regulated CUEDC2 degradation is critical for UV-induced G1 arrest.

  18. Risk factors and classifications of hilar cholangiocarcinoma.

    PubMed

    Suarez-Munoz, Miguel Angel; Fernandez-Aguilar, Jose Luis; Sanchez-Perez, Belinda; Perez-Daga, Jose Antonio; Garcia-Albiach, Beatriz; Pulido-Roa, Ysabel; Marin-Camero, Naiara; Santoyo-Santoyo, Julio

    2013-07-15

    Cholangiocarcinoma is the second most common primary malignant tumor of the liver. Perihilar cholangiocarcinoma or Klatskin tumor represents more than 50% of all biliary tract cholangiocarcinomas. A wide range of risk factors have been identified among patients with Perihilar cholangiocarcinoma including advanced age, male gender, primary sclerosing cholangitis, choledochal cysts, cholelithiasis, cholecystitis, parasitic infection (Opisthorchis viverrini and Clonorchis sinensis), inflammatory bowel disease, alcoholic cirrhosis, nonalcoholic cirrhosis, chronic pancreatitis and metabolic syndrome. Various classifications have been used to describe the pathologic and radiologic appearance of cholangiocarcinoma. The three systems most commonly used to evaluate Perihilar cholangiocarcinoma are the Bismuth-Corlette (BC) system, the Memorial Sloan-Kettering Cancer Center and the TNM classification. The BC classification provides preoperative assessment of local spread. The Memorial Sloan-Kettering cancer center proposes a staging system according to three factors related to local tumor extent: the location and extent of bile duct involvement, the presence or absence of portal venous invasion, and the presence or absence of hepatic lobar atrophy. The TNM classification, besides the usual descriptors, tumor, node and metastases, provides additional information concerning the possibility for the residual tumor (R) and the histological grade (G). Recently, in 2011, a new consensus classification for the Perihilar cholangiocarcinoma had been published. The consensus was organised by the European Hepato-Pancreato-Biliary Association which identified the need for a new staging system for this type of tumors. The classification includes information concerning biliary or vascular (portal or arterial) involvement, lymph node status or metastases, but also other essential aspects related to the surgical risk, such as remnant hepatic volume or the possibility of underlying disease.

  19. Akt phosphorylates myc-associated zinc finger protein (MAZ), releases P-MAZ from the p53 promoter, and activates p53 transcription.

    PubMed

    Lee, Wei-Ping; Lan, Keng-Hsin; Li, Chung-Pin; Chao, Yee; Lin, Han-Chieh; Lee, Shou-Dong

    2016-05-28

    The p53 protein is a cell cycle regulator. When the cell cycle progresses, p53 plays an important role in putting a brake on the G1 phase to prevent unwanted errors during cell division. Akt is a downstream kinase of receptor tyrosine kinase. Upon activation, Akt phorphorylates IKK that then phosphorylates IκB and releases NF-κB, leading to transcriptional activation of Dmp1. Dmp1 is a transcriptional activator of Arf. It has been known that oncogene activation stabilizes p53 through transcriptional activation of Arf, which then binds and inhibits Mdm2. In the current study, we show that myc-associated zinc finger protein (MAZ) is a transcriptional repressor of the p53 promoter. Akt phosphorylates MAZ at Thr385, and the phosphorylated MAZ is released from the p53 promoter, leading to transcriptional activation of p53, a new mechanism that contributes to increased p53 protein pool during oncogene activation.

  20. Cholangiocarcinoma

    MedlinePlus

    Bile duct cancer ... Bile duct cancers are slow-growing. They don't spread (metastasize) quickly. The exact cause of CCA isn't ... found. CCA may start anywhere along the bile ducts. These tumors block off the bile ducts. Both ...

  1. Long non-coding RNA MALAT1 increases AKAP-9 expression by promoting SRPK1-catalyzed SRSF1 phosphorylation in colorectal cancer cells.

    PubMed

    Hu, Zhi-Yan; Wang, Xiao-Yan; Guo, Wen-Bin; Xie, Lin-Ying; Huang, Yu-Qi; Liu, Yan-Ping; Xiao, Li-Wei; Li, Sheng-Nan; Zhu, Hui-Fang; Li, Zu-Guo; Kan, Heping

    2016-03-08

    Our earlier findings indicate that the long non-coding RNA MALAT1 promotes colorectal cancer (CRC) cell proliferation, invasion and metastasis in vitro and in vivo by increasing expression of AKAP-9. In the present study, we investigated the molecular mechanism by which MALAT1 enhances AKAP9 expression in CRC SW480 cells. We found that MALAT1 interacts with both SRPK1 and SRSF1. MALAT1 increases AKAP-9 expression by promoting SRPK1-catalyzed SRSF1 phosphorylation. Following MALAT1 knockdown, overexpression of SRPK1 was sufficient to restore SRSF1 phosphorylation and AKAP-9 expression to a level that promoted cell proliferation, invasion and migration in vitro. Conversely, SRPK1 knockdown after overexpression of MALAT1 in SW480 cells diminished SRSF1 phosphorylation and AKAP-9 expression and suppressed cell proliferation, invasion and migration in vitro. These findings suggest MALAT1 increases AKAP-9 expression by promoting SRPK1-catalyzed SRSF1 phosphorylation in CRC cells. These results reveal a novel molecular mechanism by which MALAT1 regulates AKAP-9 expression in CRC cells.

  2. Cytosolic phosphorylating glyceraldehyde-3-phosphate dehydrogenases affect Arabidopsis cellular metabolism and promote seed oil accumulation.

    PubMed

    Guo, Liang; Ma, Fangfang; Wei, Fang; Fanella, Brian; Allen, Doug K; Wang, Xuemin

    2014-07-01

    The cytosolic enzyme glyceraldehyde-3-phosphate dehydrogenase (GAPC) catalyzes a key reaction in glycolysis, but its contribution to plant metabolism and growth are not well defined. Here, we show that two cytosolic GAPCs play important roles in cellular metabolism and seed oil accumulation. Knockout or overexpression of GAPCs caused significant changes in the level of intermediates in the glycolytic pathway and the ratios of ATP/ADP and NAD(P)H/NAD(P). Two double knockout seeds had ∼3% of dry weight decrease in oil content compared with that of the wild type. In transgenic seeds under the constitutive 35S promoter, oil content was increased up to 42% of dry weight compared with 36% in the wild type and the fatty acid composition was altered; however, these transgenic lines exhibited decreased fertility. Seed-specific overexpression lines had >3% increase in seed oil without compromised seed yield or fecundity. The results demonstrate that GAPC levels play important roles in the overall cellular production of reductants, energy, and carbohydrate metabolites and that GAPC levels are directly correlated with seed oil accumulation. Changes in cellular metabolites and cofactor levels highlight the complexity and tolerance of Arabidopsis thaliana cells to the metabolic perturbation. Further implications for metabolic engineering of seed oil production are discussed. © 2014 American Society of Plant Biologists. All rights reserved.

  3. Tyr42 phosphorylation of RhoA GTPase promotes tumorigenesis through nuclear factor (NF)-κB.

    PubMed

    Kim, Jae-Gyu; Choi, Kyoung-Chan; Hong, Chang-Won; Park, Hwee-Seon; Choi, Eun-Kyoung; Kim, Yong-Sun; Park, Jae-Bong

    2017-11-01

    Dysregulation of reactive oxygen species (ROS) levels is implicated in the pathogenesis of several diseases, including cancer. However, the molecular mechanisms for ROS in tumorigenesis have not been well established. In this study, hydrogen peroxide activated nuclear factor-κB (NF-κB) and RhoA GTPase. In particular, we found that hydrogen peroxide lead to phosphorylation of RhoA at Tyr42 via tyrosine kinase Src. Phospho-Tyr42 (p-Tyr42) residue of RhoA is a binding site for Vav2, a guanine nucleotide exchange factor (GEF), which then activates p-Tyr42 form of RhoA. P-Tyr42 RhoA then binds to IκB kinase γ (IKKγ), leading to IKKβ activation. Furthermore, RhoA WT and phospho-mimic RhoA, RhoA Y42E, both promoted tumorigenesis, whereas the dephospho-mimic RhoA, RhoA Y42F suppressed it. In addition, hydrogen peroxide induced NF-κB activation and cell proliferation, along with expression of c-Myc and cyclin D1 in the presence of RhoA WT and RhoA Y42E, but not RhoA Y42F. Indeed, levels of p-Tyr42 Rho, p-Src, and p-65 are significantly increased in human breast cancer tissues and show correlations between each of the two components. Conclusively, the posttranslational modification of as RhoA p-Tyr42 may be essential for promoting tumorigenesis in response to generation of ROS. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. Chemoresistance and chemosensitization in cholangiocarcinoma.

    PubMed

    Marin, Jose J G; Lozano, Elisa; Herraez, Elisa; Asensio, Maitane; Di Giacomo, Silvia; Romero, Marta R; Briz, Oscar; Serrano, Maria A; Efferth, Thomas; Macias, Rocio I R

    2017-07-07

    One of the main difficulties in the management of patients with advanced cholangiocarcinoma (CCA) is their poor response to available chemotherapy. This is the result of powerful mechanisms of chemoresistance (MOC) of quite diverse nature that usually act synergistically. The problem is often worsened by altered MOC gene expression in response to pharmacological treatment. Since CCA includes a heterogeneous group of cancers their genetic signature coding for MOC genes is also diverse; however, several shared traits have been defined. Some of these characteristics are shared with other types of liver cancer, namely hepatocellular carcinoma and hepatoblastoma. An important goal in modern oncologic pharmacology is to develop novel strategies to overcome CCA chemoresistance either by increasing drug specificity, such as in targeted therapies aimed to inhibit receptors with tyrosine kinase activity, or to increase the amounts of active agents inside CCA cells by enhancing drug uptake or reducing efflux through export pumps. This article is part of a Special Issue entitled: Cholangiocytes in Health and Diseaseedited by Jesus Banales, Marco Marzioni, Nicholas LaRusso and Peter Jansen. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. CRM-1 knockdown inhibits extrahepatic cholangiocarcinoma tumor growth by blocking the nuclear export of p27Kip1

    PubMed Central

    Luo, Jian; Chen, Yongjun; Li, Qiang; Wang, Bing; Zhou, Yanqiong; Lan, Hongzhen

    2016-01-01

    Cholangiocarcinoma is a deadly disease which responds poorly to surgery and conventional chemotherapy or radiotherapy. Early diagnosis is difficult due to the anatomical and biological characteristics of cholangiocarcinoma. Cyclin-dependent kinase inhibitor 1B (p27Kip1) is a cyclin-dependent kinase inhibitor and in the present study, we found that p27Kip1 expression was suppressed in the nucleus and increased in the cytoplasm in 53 samples of cholangiocarcinoma from patients with highly malignant tumors (poorly-differentiated and tumor-node-metastsis (TNM) stage III–IV) compared with that in samples from 10 patients with chronic cholangitis. The expression of phosphorylated (p-)p27Kip1 (Ser10), one of the phosphorylated forms of p27Kip1, was increased in the patient samples with increasing malignancy and clinical stage. Coincidentally, chromosome region maintenance 1 (CRM-1; also referred to as exportin 1 or Xpo1), a critical protein responsible for protein translocation from the nucleus to the cytoplasm, was also overexpressed in the tumor samples which were poorly differentiated and of a higher clinical stage. Through specific short hairpin RNA (shRNA)-mediated knockdown of CRM-1 in the cholangiocarcinoma cell line QBC939, we identified an elevation of cytoplasmic p27Kip1 and a decrease of nuclear p27Kip1. Furthermore, the viability and colony formation ability of QBC939 cells was largely reduced with G1 arrest. Consistent with the findings of the in vitro experiments, in a xenograft mouse model, the tumors formed in the CRM-1 knockdown group were markedly smaller and weighed less than those in the control group in vivo. Taken together, these findings demonstrated that the interplay between CRM-1 and p27Kip1 may provide potentially potent biomarkers and functional targets for the development of future cholangiocarcinoma treatments. PMID:27279267

  6. CRM-1 knockdown inhibits extrahepatic cholangiocarcinoma tumor growth by blocking the nuclear export of p27Kip1.

    PubMed

    Luo, Jian; Chen, Yongjun; Li, Qiang; Wang, Bing; Zhou, Yanqiong; Lan, Hongzhen

    2016-08-01

    Cholangiocarcinoma is a deadly disease which responds poorly to surgery and conventional chemotherapy or radiotherapy. Early diagnosis is difficult due to the anatomical and biological characteristics of cholangiocarcinoma. Cyclin-dependent kinase inhibitor 1B (p27Kip1) is a cyclin‑dependent kinase inhibitor and in the present study, we found that p27Kip1 expression was suppressed in the nucleus and increased in the cytoplasm in 53 samples of cholangiocarcinoma from patients with highly malignant tumors (poorly-differentiated and tumor-node-metastsis (TNM) stage III-IV) compared with that in samples from 10 patients with chronic cholangitis. The expression of phosphorylated (p-)p27Kip1 (Ser10), one of the phosphorylated forms of p27Kip1, was increased in the patient samples with increasing malignancy and clinical stage. Coincidentally, chromosome region maintenance 1 (CRM-1; also referred to as exportin 1 or Xpo1), a critical protein responsible for protein translocation from the nucleus to the cytoplasm, was also overexpressed in the tumor samples which were poorly differentiated and of a higher clinical stage. Through specific short hairpin RNA (shRNA)-mediated knockdown of CRM-1 in the cholangiocarcinoma cell line QBC939, we identified an elevation of cytoplasmic p27Kip1 and a decrease of nuclear p27Kip1. Furthermore, the viability and colony formation ability of QBC939 cells was largely reduced with G1 arrest. Consistent with the findings of the in vitro experiments, in a xenograft mouse model, the tumors formed in the CRM-1 knockdown group were markedly smaller and weighed less than those in the control group in vivo. Taken together, these findings demonstrated that the interplay between CRM-1 and p27Kip1 may provide potentially potent biomarkers and functional targets for the development of future cholangiocarcinoma treatments.

  7. AML1/RUNX1 Phosphorylation by Cyclin-Dependent Kinases Regulates the Degradation of AML1/RUNX1 by the Anaphase-Promoting Complex‡

    PubMed Central

    Biggs, Joseph R.; Peterson, Luke F.; Zhang, Youhong; Kraft, Andrew S.; Zhang, Dong-Er

    2006-01-01

    AML1 (RUNX1) regulates hematopoiesis, angiogenesis, muscle function, and neurogenesis. Previous studies have shown that phosphorylation of AML1, particularly at serines 276 and 303, affects its transcriptional activation. Here, we report that phosphorylation of AML1 serines 276 and 303 can be blocked in vivo by inhibitors of the cyclin-dependent kinases (CDKs) Cdk1 and Cdk2. Furthermore, these residues can be phosphorylated in vitro by purified Cdk1/cyclin B and Cdk2/cyclin A. Mutant AML1 protein which cannot be phosphorylated at these sites (AML1-4A) is more stable than wild-type AML1. AML-4A is resistant to degradation mediated by Cdc20, one of the substrate-targeting subunits of the anaphase-promoting complex (APC). However, Cdh1, another targeting subunit used by the APC, can mediate the degradation of AML1-4A. A phospho-mimic protein, AML1-4D, can be targeted by Cdc20 or Cdh1. These observations suggest that both Cdc20 and Cdh1 can target AML1 for degradation by the APC but that AML1 phosphorylation may affect degradation mediated by Cdc20-APC to a greater degree. PMID:17015473

  8. Tumor-associated macrophages promote Ezrin phosphorylation-mediated epithelial-mesenchymal transition in lung adenocarcinoma through FUT4/LeY up-regulation.

    PubMed

    Wang, Aman; Lu, Chang; Ning, Zhen; Gao, Wei; Xie, Yunpeng; Zhang, Ningning; Liang, Jinxiao; Abbasi, Faisal S; Yan, Qiu; Liu, Jiwei

    2017-04-25

    Tumor-associated macrophages (TAMs) are key components of tumor microenvironment (TME) during tumorigenesis and progression. However, the role of TAMs in lung adenocarcinoma is still unclear. In this study, we aimed to clarify the mechanism underlying the crosstalk between TAMs and epithelial-mesenchymal transition (EMT) of lung adenocarcinoma. Fucosyltransferase IV (FUT4) and its synthetic cancer sugar antigen Lewis Y (LeY) was aberrantly elevated in various solid tumors, it plays critical role in the invasion and metastasis. Here, we found that in lung adenocarcinoma samples, the density of TAMs correlates with E-cadherin level and LeY level. In vitro assays, M2 macrophages promoted FUT4/LeY expression through the transforming growth factor-β1(TGF-β1)/Smad2/3 signaling pathway. FUT4/LeY was indispensable in M2 macrophages-mediated cytoskeletal remodeling and EMT. Furthermore, fucosylation of Ezrin mediated by FUT4/LeY can promote the phosphorylation of Ezrin, which was the critical mechanism of M2 macrophages-induced EMT. In vivo assays confirmed that M2 macrophages promoted EMT through the up-regulation of LeY and phosphorylated Ezrin. Together, our results revealed that TAMs promote Ezrin phosphorylation-mediated EMT in lung adenocarcinoma through FUT4/LeY- mediated fucosylation. Targeting this newly identified signaling may offer new possibilities for immunotherapy in lung adenocarcinoma.

  9. Promoter chromatin remodeling of immediate-early genes is mediated through H3 phosphorylation at either serine 28 or 10 by the MSK1 multi-protein complex

    PubMed Central

    Drobic, Bojan; Pérez-Cadahía, Beatriz; Yu, Jenny; Kung, Sam Kam-Pun; Davie, James R.

    2010-01-01

    Upon activation of the ERK and p38 MAPK pathways, the MSK1/2-mediated nucleosomal response, including H3 phosphorylation at serine 28 or 10, is coupled with the induction of immediate-early (IE) gene transcription. The outcome of this response, varying with the stimuli and cellular contexts, ranges from neoplastic transformation to neuronal synaptic plasticity. Here, we used sequential co-immunoprecipitation assays and sequential chromatin immunoprecipitation (ChIP) assays on mouse fibroblast 10T1/2 and MSK1 knockdown 10T1/2 cells to show that H3 serine 28 and 10 phosphorylation leads to promoter remodeling. MSK1, in complexes with phospho-serine adaptor 14-3-3 proteins and BRG1 the ATPase subunit of the SWI/SNF remodeler, is recruited to the promoter of target genes by transcription factors such as Elk-1 or NF-κB. Following MSK1-mediated H3 phosphorylation, BRG1 associates with the promoter of target genes via 14-3-3 proteins, which act as scaffolds. The recruited SWI/SNF remodels nucleosomes at the promoter of IE genes enabling the binding of transcription factors like JUN and the onset of transcription. PMID:20129940

  10. Cell cycle–regulated phosphorylation of p220NPAT by cyclin E/Cdk2 in Cajal bodies promotes histone gene transcription

    PubMed Central

    Ma, Tianlin; Van Tine, Brian A.; Wei, Yue; Garrett, Michelle D.; Nelson, David; Adams, Peter D.; Wang, Jin; Qin, Jun; Chow, Louise T.; Harper, J. Wade

    2000-01-01

    Cyclin E/Cdk2 acts at the G1/S-phase transition to promote the E2F transcriptional program and the initiation of DNA synthesis. To explore further how cyclin E/Cdk2 controls S-phase events, we examined the subcellular localization of the cyclin E/Cdk2 interacting protein p220NPAT and its regulation by phosphorylation. p220 is localized to discrete nuclear foci. Diploid fibroblasts in Go and G1 contain two p220 foci, whereas S- and G2-phase cells contain primarily four p220 foci. Cells in metaphase and telophase have no detectable focus. p220 foci contain cyclin E and are coincident with Cajal bodies (CBs), subnuclear organelles that associate with histone gene clusters on chromosomes 1 and 6. Interestingly, p220 foci associate with chromosome 6 throughout the cell cycle and with chromosome 1 during S phase. Five cyclin E/Cdk2 phosphorylation sites in p220 were identified. Phospho-specific antibodies against two of these sites react with p220 within CBs in a cell cycle–specific manner. The timing of p220 phosphorylation correlates with the appearance of cyclin E in CBs at the G1/S boundary, and this phosphorylation is maintained until prophase. Expression of p220 activates transcription of the histone H2B promoter. Importantly, mutation of Cdk2 phosphorylation sites to alanine abrogates the ability of p220 to activate the histone H2B promoter. Collectively, these results strongly suggest that p220NPAT links cyclical cyclin E/Cdk2 kinase activity to replication-dependent histone gene transcription. PMID:10995387

  11. Src-mediated phosphorylation of the tyrosine phosphatase PRL-3 is required for PRL-3 promotion of Rho activation, motility and invasion.

    PubMed

    Fiordalisi, James J; Dewar, Brian J; Graves, Lee M; Madigan, James P; Cox, Adrienne D

    2013-01-01

    The metastasis-associated tyrosine phosphatase PRL-3/PTP4A is upregulated in numerous cancers, but the mechanisms modulating PRL-3 activity other than its expression levels have not been investigated. Here we report evidence for both Src-dependent tyrosine phosphorylation of PRL-3 and Src-mediated regulation of PRL-3 biological activities. We used structural mutants, pharmacological inhibitors and siRNA to demonstrate Src-dependent phosphorylation of endogenous PRL-3 in SW480 colon cancer cells. We also demonstrated that PRL-3 was not tyrosine phosphorylated in SYF mouse embryo fibroblasts deficient in Src, Yes and Fyn unless Src was re-expressed. Further, we show that platelet-derived growth factor (PDGF) can stimulate PRL-3 phosphorylation in a Src-dependent manner. Finally, we show that PRL-3-induced cell motility, Matrigel invasion and activation of the cytoskeleton-regulating small GTPase RhoC were abrogated in the presence of the phosphodeficient PRL-3 mutant Y53F, or by use of a Src inhibitor. Thus, PRL-3 requires the activity of a Src kinase, likely Src itself, to promote these cancer-associated phenotypes. Our data establish a model for the regulation of PRL-3 by Src that supports the possibility of their coordinate roles in signaling pathways promoting invasion and metastasis, and supports simultaneous use of novel molecularly targeted therapeutics directed at these proteins.

  12. Phosphorylation of CBP by IKKα Promotes Cell Growth by Switching the Binding Preference of CBP from p53 to NF-κB

    PubMed Central

    Huang, Wei-Chien; Ju, Tsai-Kai; Hung, Mien-Chie; Chen, Ching-Chow

    2007-01-01

    Summary CBP plays a central role in coordinating and integrating multiple signaling pathways. Competition between NF-κB and p53 for CBP is a crucial determinant of whether a cell proliferates or undergoes apoptosis. However, how the CBP-dependent cross-talk between these two transcription factors is regulated remains unclear. Here, we show that IKKα phosphorylates CBP at serine 1382 and serine 1386 and consequently increases CBP’s HAT and transcriptional activities. Importantly, such phosphorylation enhances NF-κB-mediated gene expression and suppresses p53-mediated gene expression by switching the binding preference of CBP from p53 to NF-κB and thus promotes cell growth. The CBP phosphorylation also correlates with constitutive IKKα activation in human lung tumor tissue compared with matched nontumor lung tissue. Our results suggest that phosphorylation of CBP by IKKα regulates the CBP-mediated cross-talk between NF-κB and p53 and thus may be a critical factor in the promotion of cell proliferation and tumor growth. PMID:17434128

  13. Src-Mediated Phosphorylation of the Tyrosine Phosphatase PRL-3 Is Required for PRL-3 Promotion of Rho Activation, Motility and Invasion

    PubMed Central

    Fiordalisi, James J.; Dewar, Brian J.; Graves, Lee M.; Madigan, James P.; Cox, Adrienne D.

    2013-01-01

    The metastasis-associated tyrosine phosphatase PRL-3/PTP4A is upregulated in numerous cancers, but the mechanisms modulating PRL-3 activity other than its expression levels have not been investigated. Here we report evidence for both Src-dependent tyrosine phosphorylation of PRL-3 and Src-mediated regulation of PRL-3 biological activities. We used structural mutants, pharmacological inhibitors and siRNA to demonstrate Src-dependent phosphorylation of endogenous PRL-3 in SW480 colon cancer cells. We also demonstrated that PRL-3 was not tyrosine phosphorylated in SYF mouse embryo fibroblasts deficient in Src, Yes and Fyn unless Src was re-expressed. Further, we show that platelet-derived growth factor (PDGF) can stimulate PRL-3 phosphorylation in a Src-dependent manner. Finally, we show that PRL-3-induced cell motility, Matrigel invasion and activation of the cytoskeleton-regulating small GTPase RhoC were abrogated in the presence of the phosphodeficient PRL-3 mutant Y53F, or by use of a Src inhibitor. Thus, PRL-3 requires the activity of a Src kinase, likely Src itself, to promote these cancer-associated phenotypes. Our data establish a model for the regulation of PRL-3 by Src that supports the possibility of their coordinate roles in signaling pathways promoting invasion and metastasis, and supports simultaneous use of novel molecularly targeted therapeutics directed at these proteins. PMID:23691193

  14. Genetic Profiling of Intrahepatic Cholangiocarcinoma

    PubMed Central

    Andersen, Jesper B.; Thorgeirsson, Snorri S.

    2014-01-01

    Purpose of review Intrahepatic cholangiocarcinoma (ICC) is a treatment-refractory disease with a dismal outcome. Limited success in the clinical management and a persistent increase in the incidence world-wide have made ICC one of the most lethal and fastest growing malignancies. However, recent advancements in genome-wide technologies combined with the application of integrative multidimensional analytical approaches have begun to provide both detailed insight into the underlying biological traits of ICC and identified new therapeutic opportunities. Recent findings In comparison with other cancers genomic studies of ICC have been limited. We and others have recently procured large cohorts of ICC patients intended for genome-wide analyses. In our study samples from ICC patients were obtained from three cancer centers and subjected to integrated genetic and genomic analyses. We provided new insights into both pathogenesis and optimal treatment options demonstrating the presence of unique subclasses of patients, based partly on KRAS mutations and increased levels of receptor tyrosine kinase signaling. The group of patients with the worst prognosis was characterized by transcriptional enrichment of genes regulating inflammation and proteasome activities, suggesting a combination of tyrosine kinase inhibitors and anti-inflammatory drugs as a new therapeutic option for these patients. Summary We have critically examined the progress in genome-wide studies of ICC including genetic profiling, transcriptomics and epigenomics. Current limitations in applying these technologies to archival samples and the insufficient access to fresh-frozen material are partly the cause of the delayed implementation of the omics-based investigations of ICC compared to other hepatobiliary diseases. Thus, selected candidate single gene studies will also be discussed. PMID:22395571

  15. Genetic profiling of intrahepatic cholangiocarcinoma.

    PubMed

    Andersen, Jesper B; Thorgeirsson, Snorri S

    2012-05-01

    Intrahepatic cholangiocarcinoma (ICC) is a treatment-refractory disease with a dismal outcome. Limited success in the clinical management and a persistent increase in the incidence world-wide have made ICC one of the most lethal and fastest growing malignancies. However, recent advancements in genome-wide technologies combined with the application of integrative multidimensional analytical approaches have begun to provide both detailed insight into the underlying biological traits of ICC and identified new therapeutic opportunities. In comparison with other cancers, genomic studies of ICC have been limited. We and others have recently procured large cohorts of ICC patients intended for genome-wide analyses. In our study, samples from ICC patients were obtained from three cancer centers and subjected to integrated genetic and genomic analyses. We provided new insights into both pathogenesis and optimal treatment options demonstrating the presence of unique subclasses of patients, based partly on KRAS mutations and increased levels of receptor tyrosine kinase signaling. The group of patients with the worst prognosis was characterized by transcriptional enrichment of genes regulating inflammation and proteasome activities, suggesting a combination of tyrosine kinase inhibitors and anti-inflammatory drugs as a new therapeutic option for these patients. We have critically examined the progress in genome-wide studies of ICC including genetic profiling, transcriptomics, and epigenomics. Current limitations in applying these technologies to archival samples and the insufficient access to fresh-frozen material are partly the cause of the delayed implementation of the omics-based investigations of ICC compared to other hepatobiliary diseases. Thus, selected candidate single-gene studies will also be discussed.

  16. Bile duct lymphoma disguised as cholangiocarcinoma

    PubMed Central

    Jaiswal, Deepna; Wong, Lucas

    2017-01-01

    We present a case of intrabiliary primary B-cell lymphoma masked as a cholangiocarcinoma in an HIV-positive patient. The two entities have similar symptoms, laboratory findings, and imaging findings but require very different treatments. The case highlights the need to confirm the diagnosis by biopsy. PMID:28405078

  17. Phosphorylated cortactin recruits Vav2 guanine nucleotide exchange factor to activate Rac3 and promote invadopodial function in invasive breast cancer cells

    PubMed Central

    Rosenberg, Brian J.; Gil-Henn, Hava; Mader, Christopher C.; Halo, Tiffany; Yin, Taofei; Condeelis, John; Machida, Kazuya; Wu, Yi I.; Koleske, Anthony J.

    2017-01-01

    Breast carcinoma cells use specialized, actin-rich protrusions called invadopodia to degrade and invade through the extracellular matrix. Phosphorylation of the actin nucleation–promoting factor and actin-stabilizing protein cortactin downstream of the epidermal growth factor receptor–Src-Arg kinase cascade is known to be a critical trigger for invadopodium maturation and subsequent cell invasion in breast cancer cells. The functions of cortactin phosphorylation in this process, however, are not completely understood. We identify the Rho-family guanine nucleotide exchange factor Vav2 in a comprehensive screen for human SH2 domains that bind selectively to phosphorylated cortactin. We demonstrate that the Vav2 SH2 domain binds selectively to phosphotyrosine-containing peptides corresponding to cortactin tyrosines Y421 and Y466 but not to Y482. Mutation of the Vav2 SH2 domain disrupts its recruitment to invadopodia, and an SH2-domain mutant form of Vav2 cannot support efficient matrix degradation in invasive MDA-MB-231 breast cancer cells. We show that Vav2 function is required for promoting invadopodium maturation and consequent actin polymerization, matrix degradation, and invasive migratory behavior. Using biochemical assays and a novel Rac3 biosensor, we show that Vav2 promotes Rac3 activation at invadopodia. Rac3 knockdown reduces matrix degradation by invadopodia, whereas a constitutively active Rac3 can rescue the deficits in invadopodium function in Vav2-knockdown cells. Together these data indicate that phosphorylated cortactin recruits Vav2 to activate Rac3 and promote invadopodial maturation in invasive breast cancer cells. PMID:28356423

  18. Molecular dynamics simulation reveals how phosphorylation of tyrosine 26 of phosphoglycerate mutase 1 upregulates glycolysis and promotes tumor growth.

    PubMed

    Wang, Yan; Cai, Wen-Sheng; Chen, Luonan; Wang, Guanyu

    2017-02-14

    Phosphoglycerate mutase 1 (PGAM1) catalyzes the eighth step of glycolysis and is often found upregulated in cancer cells. To test the hypothesis that the phosphorylation of tyrosine 26 residue of PGAM1 greatly enhances its activity, we performed both conventional and steered molecular dynamics simulations on the binding and unbinding of PGAM1 to its substrates, with tyrosine 26 either phosphorylated or not. We analyzed the simulated data in terms of structural stability, hydrogen bond formation, binding free energy, etc. We found that tyrosine 26 phosphorylation enhances the binding of PGAM1 to its substrates through generating electrostatic environment and structural features that are advantageous to the binding. Our results may provide valuable insights into computer-aided design of drugs that specifically target cancer cells with PGAM1 tyrosine 26 phosphorylated.

  19. Green tea polyphenol EGCG suppresses Wnt/β-catenin signaling by promoting GSK-3β- and PP2A-independent β-catenin phosphorylation/degradation

    PubMed Central

    Oh, Sangtaek; Gwak, Jungsug; Park, Seoyoung; Yang, Chung S.

    2014-01-01

    (−)-Epigallocatechin-3-gallate (EGCG), the major polyphenol in green tea, has been reported to inhibit the Wnt/β-catenin pathway, which is aberrantly up-regulated in colorectal cancers, but its precise mechanism of action remains unclear. Here, we used a sensitive cell-based system to demonstrate that EGCG suppresses β-catenin response transcription (CRT), activated by Wnt3a-conditioned medium (Wnt3a-CM), by promoting the degradation of intracellular β-catenin. EGCG induced β-catenin N-terminal phosphorylation at the Ser33/37 residues and subsequently promoted its degradation; however, this effect was not observed for oncogenic forms of β-catenin. Pharmacological inhibition or depletion of glycogen synthase kinase-3β (GSK-3β) did not abrogate the EGCG-mediated β-catenin degradation. EGCG did not affect the activity and expression of protein phosphatase 2A (PP2A). Consistently, the phosphorylation and degradation of β-catenin was found in adenomatous polyposis coli (APC) mutated colon cancer cells after EGCG treatment. EGCG repressed the expression of cyclin D1 and c-myc, which are β-catenin/T-cell factor-dependent genes, and inhibited the proliferation of colon cancer cells. Our findings suggest that EGCG exerts its cancer-preventive or anticancer activity against colon cancer cells by promoting the phosphorylation and proteasomal degradation of β-catenin through a mechanism independent of the GSK-3β and PP2A. PMID:25352148

  20. Treatment of Leptomeningeal Carcinomatosis in a Patient With Metastatic Cholangiocarcinoma

    PubMed Central

    McNeill, Katharine; Volpicelli, Frank M.; Warltier, Karin; Iturrate, Eduardo; Okamura, Charles; Adler, Nicole; Smith, Joshua; Sigmund, Alana; Mednick, Aron; Wertheimer, Benjamin; Hochman, Katherine

    2014-01-01

    A 49-year-old woman with cholangiocarcinoma metastatic to the lungs presented with new-onset unrelenting headaches. A lumbar puncture revealed malignant cells consistent with leptomeningeal metastasis from her cholangiocarcinoma. Magnetic resonance imaging (MRI) of the brain revealed leptomeningeal enhancement. An intrathecal (IT) catheter was placed and IT chemotherapy was initiated with methotrexate. Her case is notable for the rarity of cholangiocarcinoma spread to the leptomeninges, the use of IT chemotherapy with cytologic and potentially symptomatic response, and a possible survival benefit in comparison to previously reported cases of leptomeningeal carcinomatosis secondary to cholangiocarcinoma. PMID:26157901

  1. The Pseudomonas syringae effector HopQ1 promotes bacterial virulence and interacts with tomato 14-3-3 proteins in a phosphorylation-dependent manner.

    PubMed

    Li, Wei; Yadeta, Koste A; Elmore, James Mitch; Coaker, Gitta

    2013-04-01

    A key virulence strategy of bacterial pathogens is the delivery of multiple pathogen effector proteins into host cells during infection. The Hrp outer protein Q (HopQ1) effector from Pseudomonas syringae pv tomato (Pto) strain DC3000 is conserved across multiple bacterial plant pathogens. Here, we investigated the virulence function and host targets of HopQ1 in tomato (Solanum lycopersicum). Transgenic tomato lines expressing dexamethasone-inducible HopQ1 exhibited enhanced disease susceptibility to virulent Pto DC3000, the Pto ΔhrcC mutant, and decreased expression of a pathogen-associated molecular pattern-triggered marker gene after bacterial inoculation. HopQ1-interacting proteins were coimmunoprecipitated and identified by mass spectrometry. HopQ1 can associate with multiple tomato 14-3-3 proteins, including TFT1 and TFT5. HopQ1 is phosphorylated in tomato, and four phosphorylated peptides were identified by mass spectrometry. HopQ1 possesses a conserved mode I 14-3-3 binding motif whose serine-51 residue is phosphorylated in tomato and regulates its association with TFT1 and TFT5. Confocal microscopy and fractionation reveal that HopQ1 exhibits nucleocytoplasmic localization, while HopQ1 dephosphorylation mimics exhibit more pronounced nuclear localization. HopQ1 delivered from Pto DC3000 was found to promote bacterial virulence in the tomato genotype Rio Grande 76R. However, the HopQ1(S51A) mutant delivered from Pto DC3000 was unable to promote pathogen virulence. Taken together, our data demonstrate that HopQ1 enhances bacterial virulence and associates with tomato 14-3-3 proteins in a phosphorylation-dependent manner that influences HopQ1's subcellular localization and virulence-promoting activities in planta.

  2. ADP-Dependent Phosphorylation Regulates Association of a DNA-Binding Complex with the Barley Chloroplast psbD Blue-Light-Responsive Promoter1

    PubMed Central

    Kim, Minkyun; Christopher, David A.; Mullet, John E.

    1999-01-01

    The chloroplast gene psbD encodes D2, a chlorophyll-binding protein located in the photosystem II reaction center. Transcription of psbD in higher plants involves at least three promoters, one of which is regulated by blue light. The psbD blue-light-regulated promoter (BLRP) consists of a −10 promoter element and an activating complex, AGF, that binds immediately upstream of −35. A second sequence-specific DNA-binding complex, PGTF, binds upstream of AGF between −71 and −100 in the barley (Hordeum vulgare) psbD BLRP. In this study we report that ADP-dependent phosphorylation selectively inhibits the binding of PGTF to the barley psbD BLRP. ATP at high concentrations (1–5 mm) inhibits PGTF binding, but in the presence of phosphocreatine and phosphocreatine kinase, this capacity is lost, presumably due to scavenging of ADP. ADP inhibits PGTF binding at relatively low concentrations (0.1 mm), whereas other nucleotides are unable to mediate this response. ADP-mediated inhibition of PGTF binding is reduced in the presence of the protein kinase inhibitor K252a. This and other results suggest that ADP-dependent phosphorylation of PGTF (or some associated protein) inhibits binding of PGTF to the psbD BLRP and reduces transcription. ADP-dependent phosphorylation is expected to increase in darkness in parallel with the rise in ADP levels in chloroplasts. ADP-dependent phosphorylation in chloroplasts may, therefore, in coordination, inactivate enzymes involved in carbon assimilation, protein synthesis, and transcription during diurnal light/dark cycles. PMID:9952463

  3. Repression vs. activation of MOX, FMD, MPP1 and MAL1 promoters by sugars in Hansenula polymorpha: the outcome depends on cell's ability to phosphorylate sugar.

    PubMed

    Suppi, Sandra; Michelson, Tiina; Viigand, Katrin; Alamäe, Tiina

    2013-03-01

    A high-throughput approach was used to assess the effect of mono- and disaccharides on MOX, FMD, MPP1 and MAL1 promoters in Hansenula polymorpha. Site-specifically designed strains deficient for (1) hexokinase, (2) hexokinase and glucokinase, (3) maltose permease or (4) maltase were used as hosts for reporter plasmids in which β-glucuronidase (Gus) expression was controlled by these promoters. The reporter strains were grown on agar plates containing varied carbon sources and Gus activity was measured in permeabilized cells on microtitre plates. We report that monosaccharides (glucose, fructose) repress studied promoters only if phosphorylated in the cell. Glucose-6-phosphate was proposed as a sugar repression signalling metabolite for H. polymorpha. Intriguingly, glucose and fructose strongly activated expression from these promoters in strains lacking both hexokinase and glucokinase, indicating that unphosphorylated monosaccharides have promoter-derepressing effect. We also show that maltose and sucrose must be internalized and split into monosaccharides to exert repression on MOX promoter. We demonstrate that at yeast growth on glucose-containing agar medium, glucose-limitation is rapidly created that promotes derepression of methanol-specific promoters and that derepression is specifically enhanced in hexokinase-negative strain. We recommend double kinase-negative and hexokinase-negative mutants as hosts for heterologous protein production from MOX and FMD promoters.

  4. Phosphorylation and cleavage of presenilin-associated rhomboid-like protein (PARL) promotes changes in mitochondrial morphology

    PubMed Central

    Jeyaraju, Danny V.; Xu, Liqun; Letellier, Marie-Claude; Bandaru, Sirisha; Zunino, Rodolfo; Berg, Eric A.; McBride, Heidi M.; Pellegrini, Luca

    2006-01-01

    Remodeling of mitochondria is a dynamic process coordinated by fusion and fission of the inner and outer membranes of the organelle, mediated by a set of conserved proteins. In metazoans, the molecular mechanism behind mitochondrial morphology has been recruited to govern novel functions, such as development, calcium signaling, and apoptosis, which suggests that novel mechanisms should exist to regulate the conserved membrane fusion/fission machinery. Here we show that phosphorylation and cleavage of the vertebrate-specific Pβ domain of the mammalian presenilin-associated rhomboid-like (PARL) protease can influence mitochondrial morphology. Phosphorylation of three residues embedded in this domain, Ser-65, Thr-69, and Ser-70, impair a cleavage at position Ser77–Ala78 that is required to initiate PARL-induced mitochondrial fragmentation. Our findings reveal that PARL phosphorylation and cleavage impact mitochondrial dynamics, providing a blueprint to study the molecular evolution of mitochondrial morphology. PMID:17116872

  5. The phosphorylation of HIV-1 Gag by atypical protein kinase C facilitates viral infectivity by promoting Vpr incorporation into virions

    PubMed Central

    2014-01-01

    Background Human immunodeficiency virus type 1 (HIV-1) Gag is the main structural protein that mediates the assembly and release of virus-like particles (VLPs) from an infected cell membrane. The Gag C-terminal p6 domain contains short sequence motifs that facilitate virus release from the plasma membrane and mediate incorporation of the viral Vpr protein. Gag p6 has also been found to be phosphorylated during HIV-1 infection and this event may affect virus replication. However, the kinase that directs the phosphorylation of Gag p6 toward virus replication remains to be identified. In our present study, we identified this kinase using a proteomic approach and further delineate its role in HIV-1 replication. Results A proteomic approach was designed to systematically identify human protein kinases that potently interact with HIV-1 Gag and successfully identified 22 candidates. Among this panel, atypical protein kinase C (aPKC) was found to phosphorylate HIV-1 Gag p6. Subsequent LC-MS/MS and immunoblotting analysis with a phospho-specific antibody confirmed both in vitro and in vivo that aPKC phosphorylates HIV-1 Gag at Ser487. Computer-assisted structural modeling and a subsequent cell-based assay revealed that this phosphorylation event is necessary for the interaction between Gag and Vpr and results in the incorporation of Vpr into virions. Moreover, the inhibition of aPKC activity reduced the Vpr levels in virions and impaired HIV-1 infectivity of human primary macrophages. Conclusion Our current results indicate for the first time that HIV-1 Gag phosphorylation on Ser487 is mediated by aPKC and that this kinase may regulate the incorporation of Vpr into HIV-1 virions and thereby supports virus infectivity. Furthermore, aPKC inhibition efficiently suppresses HIV-1 infectivity in macrophages. aPKC may therefore be an intriguing therapeutic target for HIV-1 infection. PMID:24447338

  6. ATM regulates NF-κB-dependent immediate-early genes via RelA Ser 276 phosphorylation coupled to CDK9 promoter recruitment

    PubMed Central

    Fang, Ling; Choudhary, Sanjeev; Zhao, Yingxin; Edeh, Chukwudi B; Yang, Chunying; Boldogh, Istvan; Brasier, Allan R.

    2014-01-01

    Ataxia-telangiectasia mutated (ATM), a member of the phosphatidylinositol 3 kinase-like kinase family, is a master regulator of the double strand DNA break-repair pathway after genotoxic stress. Here, we found ATM serves as an essential regulator of TNF-induced NF-kB pathway. We observed that TNF exposure of cells rapidly induced DNA double strand breaks and activates ATM. TNF-induced ROS promote nuclear IKKγ association with ubiquitin and its complex formation with ATM for nuclear export. Activated cytoplasmic ATM is involved in the selective recruitment of the E3-ubiquitin ligase β-TrCP to phospho-IκBα proteosomal degradation. Importantly, ATM binds and activates the catalytic subunit of protein kinase A (PKAc), ribosmal S6 kinase that controls RelA Ser 276 phosphorylation. In ATM knockdown cells, TNF-induced RelA Ser 276 phosphorylation is significantly decreased. We further observed decreased binding and recruitment of the transcriptional elongation complex containing cyclin dependent kinase-9 (CDK9; a kinase necessary for triggering transcriptional elongation) to promoters of NF-κB-dependent immediate-early cytokine genes, in ATM knockdown cells. We conclude that ATM is a nuclear damage-response signal modulator of TNF-induced NF-κB activation that plays a key scaffolding role in IκBα degradation and RelA Ser 276 phosphorylation. Our study provides a mechanistic explanation of decreased innate immune response associated with A-T mutation. PMID:24957606

  7. Spanish Experience in Liver Transplantation for Hilar and Peripheral Cholangiocarcinoma

    PubMed Central

    Robles, Ricardo; Figueras, Joan; Turrión, Victor S.; Margarit, Carlos; Moya, Angel; Varo, Evaristo; Calleja, Javier; Valdivieso, Andres; Valdecasas, Juan Carlos G.; López, Pedro; Gómez, Manuel; de Vicente, Emilio; Loinaz, Carmelo; Santoyo, Julio; Fleitas, Manuel; Bernardos, Angel; Lladó, Laura; Ramírez, Pablo; Bueno, F S.; Jaurrieta, Eduardo; Parrilla, Pascual

    2004-01-01

    Objective: To assess the real utility of orthotopic liver transplantation (OLT) in patients with cholangiocarcinoma, we need series with large numbers of cases and long follow-ups. The aim of this paper is to review the Spanish experience in OLT for hilar and peripheral cholangiocarcinoma and to try to identify the prognostic factors that could influence survival. Summary Background Data: Palliative treatment of nondisseminated irresectable cholangiocarcinoma carries a zero 5-year survival rate. The role of OLT in these patients is controversial, due to the fact that the survival rate is lower than with other indications for transplantation and due to the lack of organs. Methods: We retrospectively reviewed 59 patients undergoing OLT in Spain for cholangiocarcinoma (36 hilar and 23 peripheral) over a period of 13 years. We present the results and prognostic factors that influence survival. Results: The actuarial survival rate for hilar cholangiocarcinoma at 1, 3, and 5 years was 82%, 53%, and 30%, and for peripheral cholangiocarcinoma 77%, 65%, and 42%. The main cause of death, with both types of cholangiocarcinoma, was tumor recurrence (present in 53% and 35% of patients, respectively). Poor prognosis factors were vascular invasion (P < 0.01) and IUAC classification stages III–IVA (P < 0.01) for hilar cholangiocarcinoma and perineural invasion (P < 0.05) and stages III-IVA (P < 0.05) for peripheral cholangiocarcinoma. Conclusions: OLT for nondisseminated irresectable cholangiocarcinoma has higher survival rates at 3 and 5 years than palliative treatments, especially with tumors in their initial stages, which means that more information is needed to help better select cholangiocarcinoma patients for transplantation. PMID:14745336

  8. Androgen signaling promotes translation of TMEFF2 in prostate cancer cells via phosphorylation of the α subunit of the translation initiation factor 2.

    PubMed

    Overcash, Ryan F; Chappell, Vesna A; Green, Thomas; Geyer, Christopher B; Asch, Adam S; Ruiz-Echevarría, Maria J

    2013-01-01

    The type I transmembrane protein with epidermal growth factor and two follistatin motifs 2 (TMEFF2), is expressed mainly in brain and prostate. Expression of TMEFF2 is deregulated in prostate cancer, suggesting a role in this disease, but the molecular mechanism(s) involved in this effect are not clear. Although androgens promote tmeff2 transcription, androgen delivery to castrated animals carrying CWR22 xenografts increases TMEFF2 protein levels in the absence of mRNA changes, suggesting that TMEFF2 may also be post-transcriptionally regulated. Here we show that translation of TMEFF2 is regulated by androgens. Addition of physiological concentrations of dihydrotestosterone (DHT) to prostate cancer cell lines increases translation of endogenous TMEFF2 or transfected TMEFF2-Luciferase fusions, and this effect requires the presence of upstream open reading frames (uORFs) in the 5'-untranslated region (5'-UTR) of TMEFF2. Using chemical and siRNA inhibition of the androgen receptor (AR), we show that the androgen effect on TMEFF2 translation is mediated by the AR. Importantly, DHT also promotes phosphorylation of the α subunit of the translation initiation factor 2 (eIF2α) in an AR-dependent manner, paralleling the effect on TMEFF2 translation. Moreover, endoplasmic reticulum (ER) stress conditions, which promote eIF2α phosphorylation, also stimulate TMEFF2 translation. These results indicate that androgen signaling promotes eIF2α phosphorylation and subsequent translation of TMEFF2 via a mechanism that requires uORFs in the 5'-UTR of TMEFF2.

  9. Androgen Signaling Promotes Translation of TMEFF2 in Prostate Cancer Cells via Phosphorylation of the α Subunit of the Translation Initiation Factor 2

    PubMed Central

    Overcash, Ryan F.; Chappell, Vesna A.; Green, Thomas; Geyer, Christopher B.; Asch, Adam S.; Ruiz-Echevarría, Maria J.

    2013-01-01

    The type I transmembrane protein with epidermal growth factor and two follistatin motifs 2 (TMEFF2), is expressed mainly in brain and prostate. Expression of TMEFF2 is deregulated in prostate cancer, suggesting a role in this disease, but the molecular mechanism(s) involved in this effect are not clear. Although androgens promote tmeff2 transcription, androgen delivery to castrated animals carrying CWR22 xenografts increases TMEFF2 protein levels in the absence of mRNA changes, suggesting that TMEFF2 may also be post-transcriptionally regulated. Here we show that translation of TMEFF2 is regulated by androgens. Addition of physiological concentrations of dihydrotestosterone (DHT) to prostate cancer cell lines increases translation of endogenous TMEFF2 or transfected TMEFF2-Luciferase fusions, and this effect requires the presence of upstream open reading frames (uORFs) in the 5′-untranslated region (5′-UTR) of TMEFF2. Using chemical and siRNA inhibition of the androgen receptor (AR), we show that the androgen effect on TMEFF2 translation is mediated by the AR. Importantly, DHT also promotes phosphorylation of the α subunit of the translation initiation factor 2 (eIF2α) in an AR-dependent manner, paralleling the effect on TMEFF2 translation. Moreover, endoplasmic reticulum (ER) stress conditions, which promote eIF2α phosphorylation, also stimulate TMEFF2 translation. These results indicate that androgen signaling promotes eIF2α phosphorylation and subsequent translation of TMEFF2 via a mechanism that requires uORFs in the 5′-UTR of TMEFF2. PMID:23405127

  10. Phosphorylation of human TFAM in mitochondria impairs DNA binding and promotes degradation by the AAA+ Lon protease.

    PubMed

    Lu, Bin; Lee, Jae; Nie, Xiaobo; Li, Min; Morozov, Yaroslav I; Venkatesh, Sundararajan; Bogenhagen, Daniel F; Temiakov, Dmitry; Suzuki, Carolyn K

    2013-01-10

    Human mitochondrial transcription factor A (TFAM) is a high-mobility group (HMG) protein at the nexus of mitochondrial DNA (mtDNA) replication, transcription, and inheritance. Little is known about the mechanisms underlying its posttranslational regulation. Here, we demonstrate that TFAM is phosphorylated within its HMG box 1 (HMG1) by cAMP-dependent protein kinase in mitochondria. HMG1 phosphorylation impairs the ability of TFAM to bind DNA and to activate transcription. We show that only DNA-free TFAM is degraded by the Lon protease, which is inhibited by the anticancer drug bortezomib. In cells with normal mtDNA levels, HMG1-phosphorylated TFAM is degraded by Lon. However, in cells with severe mtDNA deficits, nonphosphorylated TFAM is also degraded, as it is DNA free. Depleting Lon in these cells increases levels of TFAM and upregulates mtDNA content, albeit transiently. Phosphorylation and proteolysis thus provide mechanisms for rapid fine-tuning of TFAM function and abundance in mitochondria, which are crucial for maintaining and expressing mtDNA.

  11. Heparanase promotes human gastric cancer cells migration and invasion by increasing Src and p38 phosphorylation expression.

    PubMed

    Ma, Xiu Mei; Shen, Zhi Hua; Liu, Zhi Yao; Wang, Fang; Hai, Ling; Gao, Lin Tao; Wang, Hai Sheng

    2014-01-01

    Gastric cancer is one of the most common cancers and it remains difficult to cure, primarily because most cancer stem like cells possess higher capability of invasion and metastasis. Heparanase acts as a master regulator of the aggressive tumor phenotype in part by enhancing expression of proteins and activating signaling molecules. There were less associated with heparanase of molecular biology mechanism in human gastric cancer. We first evaluated the endogenous expression of heparanase in human gastric cancer cell lines and found Heparanase expression higher in SGC-7901 than MGC-803. Using the technology of RNAi in SGC-7901 cells down regulated heparanase gene, and reduced SGC-7901 cells migration and invasion. On the other hand, recombinant heparanase protein added in MGC-803 cells enhanced MGC-803 cell migration and invasion. The elevated cell migration and invasion were impaired by treatment of Src inhibitor pp2 or p38 inhibitor SB 203580. We further found that Stable knockdown of heparanase in SGC-7901 cells decreased phosphorylation of Src and p38. The phosphorylation of p38 was inhibited in response to pp2 treatment while the addition of SB 203580 to SGC-7901 cells did not change phosphorylation of Src. These data suggest that heparanase facilitates invasion and migration of human gastric cancer cells probably through elevating phosphorylation of Src and p38.

  12. Hyper-O-GlcNAcylation of YB-1 affects Ser102 phosphorylation and promotes cell proliferation in hepatocellular carcinoma.

    PubMed

    Liu, Qingqing; Tao, Tao; Liu, Fang; Ni, Runzhou; Lu, Cuihua; Shen, Aiguo

    2016-12-10

    As an essential post-translational modification, O-GlcNAcylation has been thought to be able to modulate various nuclear and cytoplasmic proteins and is emerging as a key regulator of multiple biological processes, such as transcription, cell growth, signal transduction, and cell motility. Recently, authoritative glycomics analyses have reported extensive crosstalk between O-GlcNAcylation and phosphorylation, which always dynamically interplay with each other and regulate signaling, transcription, and other cellular processes. Also, plentiful studies have shown close correlation between YB-1 phosphorylation and tumorigenesis. Therefore, our study aimed to determine whether YB-1 was O-GlcNAc modified and whether such modification could interact with its phosphorylation during the process of HCC development. Western blot and immunohistochemistry were firstly conducted to reveal obvious up-regulation of YB-1, OGT and O-GlcNAc modification in HCC tissues. What is more, not only YB-1 was identified to be O-GlcNAcylated but hyper-O-GlcNAcylation was demonstrated to facilitate HCC cell proliferation in a YB-1 dependent manner. Moreover, we detected four specific O-GlcNAc sites and confirmed T126A to be the most effective mutant in HCC cell proliferation via close O-GlcNAcylation-phosphorylation interaction. Even more interestingly, we discovered that T126A-induced HCC cell retardation and subdued transcriptional activity of YB-1 could be partially reversed by T126A/S102E mutant. From all above, it is not difficult to find that glycosylated-YB-1 mainly enhanced cell proliferation through congenerous actions with YB-1 phosphorylation and thus played indispensable roles in fine-tuning cell proliferation and procession of HCC.

  13. Heterozygosity for the alpha1-antitrypsin Z allele may confer genetic risk of cholangiocarcinoma.

    PubMed

    Mihalache, F; Höblinger, A; Grünhage, F; Krawczyk, M; Gärtner, B C; Acalovschi, M; Sauerbruch, T; Lammert, F; Zimmer, V

    2011-02-01

    Alpha1-antitrypsin (α1AT) deficiency caused by Z allele homozygosity represents a well-established risk factor for hepatocellular carcinoma. Previous studies have also implicated α1AT Z heterozygosity in cholangiocarcinogenesis. To assess the 'common' Z and S alleles as well as the promoter variant rs8004738 for association with cholangiocarcinoma. We genotyped 182 Caucasian patients and 350 controls for rs28929474 (Z), rs17580 (S) and the variant rs8004738. Exploratory analyses were performed in relation to gender and cholangiocarcinoma localisation. rs28929474 was significantly enriched in the cholangiocarcinoma group (4.1 vs. 1.7%; OR 2.46, 95% CI 1.14-5.32; Bonferroni corrected p(c) = 0.036), reinforced by Armitage trend testing (OR 2.53; p(c) = 0.032). The rs8004738 (promoter) minor allele tended to be overrepresented in Z heterozygotes (30.0 vs. 16.7%: P = 0.13). Exploratory data analyses suggested a high genetic risk for extrahepatic tumour localisation (OR 3.0; p(c) = 0.016) and potentially female Z allele carriers (OR 3.37; unadjusted P = 0.022, p(c) = 0.088). These data point to a novel role of α1AT Z heterozygosity as a potential genetic susceptibility factor for cholangiocarcinoma formation and suggest a contribution of aberrant α1AT function in biliary carcinogenesis. However, given the overall low rs28929474 minor allele frequency, larger studies are warranted to confirm and extend our findings. © 2010 Blackwell Publishing Ltd.

  14. Long-term obesity promotes alterations in diastolic function induced by reduction of phospholamban phosphorylation at serine-16 without affecting calcium handling

    PubMed Central

    Leopoldo, André S.; da Silva, Danielle C. T.; do Nascimento, André F.; de Campos, Dijon H. S.; Luvizotto, Renata A. M.; de Deus, Adriana F.; Freire, Paula P.; Medeiros, Alessandra; Okoshi, Katashi; Cicogna, Antonio C.

    2014-01-01

    Few studies have evaluated the relationship between the duration of obesity, cardiac function, and the proteins involved in myocardial calcium (Ca2+) handling. We hypothesized that long-term obesity promotes cardiac dysfunction due to a reduction of expression and/or phosphorylation of myocardial Ca2+-handling proteins. Thirty-day-old male Wistar rats were distributed into two groups (n = 10 each): control (C; standard diet) and obese (Ob; high-fat diet) for 30 wk. Morphological and histological analyses were assessed. Left ventricular cardiac function was assessed in vivo by echocardiographic evaluation and in vitro by papillary muscle. Cardiac protein expression of sarcoplasmic reticulum (SR) Ca2+-ATPase (SERCA2a), calsequestrin, L-type Ca2+ channel, and phospholamban (PLB), as well as PLB serine-16 phosphorylation (pPLB Ser16) and PLB threonine-17 phosphorylation (pPLB Thr17) were determined by Western blot. The adiposity index was higher (82%) in Ob rats than in C rats. Obesity promoted cardiac hypertrophy without alterations in interstitial collagen levels. Ob rats had increased endocardial and midwall fractional shortening, posterior wall shortening velocity, and A-wave compared with C rats. Cardiac index, early-to-late diastolic mitral inflow ratio, and isovolumetric relaxation time were lower in Ob than in C. The Ob muscles developed similar baseline data and myocardial responsiveness to increased extracellular Ca2+. Obesity caused a reduction in cardiac pPLB Ser16 and the pPLB Ser16/PLB ratio in Ob rats. Long-term obesity promotes alterations in diastolic function, most likely due to the reduction of pPLB Ser16, but does not impair the myocardial Ca2+ entry and recapture to SR. PMID:24970855

  15. Hilar cholangiocarcinoma with intratumoral calcification: A case report

    PubMed Central

    Inoko, Kazuho; Tsuchikawa, Takahiro; Noji, Takehiro; Kurashima, Yo; Ebihara, Yuma; Tamoto, Eiji; Nakamura, Toru; Murakami, Soichi; Okamura, Keisuke; Shichinohe, Toshiaki; Hirano, Satoshi

    2015-01-01

    This report describes a rare case of hilar cholangiocarcinoma with intratumoral calcification that mimicked hepatolithiasis. A 73-year-old man presented to a local hospital with a calcified lesion in the hepatic hilum. At first, hepatolithiasis was diagnosed, and he underwent endoscopic stone extraction via the trans-papillary route. This treatment strategy failed due to biliary stricture. He was referred to our hospital, and further examination suggested the existence of cholangiocarcinoma. He underwent left hepatectomy with caudate lobectomy and extrahepatic bile duct resection. Pathological examination revealed hilar cholangiocarcinoma with intratumoral calcification, while no stones were found. To the best of our knowledge, only one case of calcified hilar cholangiocarcinoma has been previously reported in the literature. Here, we report a rare case of calcified hilar cholangiocarcinoma and reveal its clinicopathologic features. PMID:26478684

  16. Phosphorylation of the centrosomal protein, Cep169, by Cdk1 promotes its dissociation from centrosomes in mitosis.

    PubMed

    Mori, Yusuke; Inoue, Yoko; Taniyama, Yuki; Tanaka, Sayori; Terada, Yasuhiko

    2015-12-25

    Cep169 is a centrosomal protein conserved among vertebrates. In our previous reports, we showed that mammalian Cep169 interacts and collaborates with CDK5RAP2 to regulate microtubule (MT) dynamics and stabilization. Although Cep169 is required for MT regulation, its precise cellular function remains largely elusive. Here we show that Cep169 associates with centrosomes during interphase, but dissociates from these structures from the onset of mitosis, although CDK5RAP2 (Cep215) is continuously located at the centrosomes throughout cell cycle. Interestingly, treatment with purvalanol A, a Cdk1 inhibitor, nearly completely blocked the dissociation of Cep169 from centrosomes during mitosis. In addition, mass spectrometry analyses identified 7 phosphorylated residues of Cep169 corresponding to consensus phosphorylation sequence for Cdk1. These data suggest that the dissociation of Cep169 from centrosomes is controlled by Cdk1/Cyclin B during mitosis, and that Cep169 might regulate MT dynamics of mitotic spindle.

  17. Protein Kinase D1 (PKD1) Phosphorylation Promotes Dopaminergic Neuronal Survival during 6-OHDA-Induced Oxidative Stress

    PubMed Central

    Asaithambi, Arunkumar; Ay, Muhammet; Jin, Huajun; Gosh, Anamitra; Anantharam, Vellareddy; Kanthasamy, Arthi; Kanthasamy, Anumantha G.

    2014-01-01

    Oxidative stress is a major pathophysiological mediator of degenerative processes in many neurodegenerative diseases including Parkinson’s disease (PD). Aberrant cell signaling governed by protein phosphorylation has been linked to oxidative damage of dopaminergic neurons in PD. Although several studies have associated activation of certain protein kinases with apoptotic cell death in PD, very little is known about protein kinase regulation of cell survival and protection against oxidative damage and degeneration in dopaminergic neurons. Here, we characterized the PKD1-mediated protective pathway against oxidative damage in cell culture models of PD. Dopaminergic neurotoxicant 6-hydroxy dopamine (6-OHDA) was used to induce oxidative stress in the N27 dopaminergic cell model and in primary mesencephalic neurons. Our results indicated that 6-OHDA induced the PKD1 activation loop (PKD1S744/S748) phosphorylation during early stages of oxidative stress and that PKD1 activation preceded cell death. We also found that 6-OHDA rapidly increased phosphorylation of the C-terminal S916 in PKD1, which is required for PKD1 activation loop (PKD1S744/748) phosphorylation. Interestingly, negative modulation of PKD1 activation by RNAi knockdown or by the pharmacological inhibition of PKD1 by kbNB-14270 augmented 6-OHDA-induced apoptosis, while positive modulation of PKD1 by the overexpression of full length PKD1 (PKD1WT) or constitutively active PKD1 (PKD1S744E/S748E) attenuated 6-OHDA-induced apoptosis, suggesting an anti-apoptotic role for PKD1 during oxidative neuronal injury. Collectively, our results demonstrate that PKD1 signaling plays a cell survival role during early stages of oxidative stress in dopaminergic neurons and therefore, positive modulation of the PKD1-mediated signal transduction pathway can provide a novel neuroprotective strategy against PD. PMID:24806360

  18. Stepwise phosphorylation of p65 promotes NF-κB activation and NK cell responses during target cell recognition

    PubMed Central

    Kwon, Hyung-Joon; Choi, Go-Eun; Ryu, Sangryeol; Kwon, Soon Jae; Kim, Sun Chang; Booth, Claire; Nichols, Kim E.; Kim, Hun Sik

    2016-01-01

    NF-κB is a key transcription factor that dictates the outcome of diverse immune responses. How NF-κB is regulated by multiple activating receptors that are engaged during natural killer (NK)-target cell contact remains undefined. Here we show that sole engagement of NKG2D, 2B4 or DNAM-1 is insufficient for NF-κB activation. Rather, cooperation between these receptors is required at the level of Vav1 for synergistic NF-κB activation. Vav1-dependent synergistic signalling requires a separate PI3K-Akt signal, primarily mediated by NKG2D or DNAM-1, for optimal p65 phosphorylation and NF-κB activation. Vav1 controls downstream p65 phosphorylation and NF-κB activation. Synergistic signalling is defective in X-linked lymphoproliferative disease (XLP1) NK cells entailing 2B4 dysfunction and required for p65 phosphorylation by PI3K-Akt signal, suggesting stepwise signalling checkpoint for NF-κB activation. Thus, our study provides a framework explaining how signals from different activating receptors are coordinated to determine specificity and magnitude of NF-κB activation and NK cell responses. PMID:27221592

  19. Frizzled-Induced Van Gogh Phosphorylation by CK1ε Promotes Asymmetric Localization of Core PCP Factors in Drosophila.

    PubMed

    Kelly, Lindsay K; Wu, Jun; Yanfeng, Wang A; Mlodzik, Marek

    2016-07-12

    Epithelial tissues are polarized along two axes. In addition to apical-basal polarity, they are often polarized within the plane of the epithelium, so-called Planar Cell Polarity (PCP). PCP depends upon Wnt/Frizzled (Fz) signaling factors, including Fz itself and Van Gogh (Vang/Vangl). We sought to understand how Vang interaction with other core PCP factors affects Vang function. We find that Fz induces Vang phosphorylation in a cell-autonomous manner. Vang phosphorylation occurs on conserved N-terminal serine/threonine residues, is mediated by CK1ε/Dco, and is critical for polarized membrane localization of Vang and other PCP proteins. This regulatory mechanism does not require Fz signaling through Dishevelled and thus represents a cell-autonomous upstream interaction between Fz and Vang. Furthermore, this signaling event appears to be related to Wnt5a-mediated Vangl2 phosphorylation during mouse limb patterning and may thus be a general mechanism underlying Wnt-regulated PCP establishment. Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.

  20. Glucose Sensor MdHXK1 Phosphorylates and Stabilizes MdbHLH3 to Promote Anthocyanin Biosynthesis in Apple.

    PubMed

    Hu, Da-Gang; Sun, Cui-Hui; Zhang, Quan-Yan; An, Jian-Ping; You, Chun-Xiang; Hao, Yu-Jin

    2016-08-01

    Glucose induces anthocyanin accumulation in many plant species; however, the molecular mechanism involved in this process remains largely unknown. Here, we found that apple hexokinase MdHXK1, a glucose sensor, was involved in sensing exogenous glucose and regulating anthocyanin biosynthesis. In vitro and in vivo assays suggested that MdHXK1 interacted directly with and phosphorylated an anthocyanin-associated bHLH transcription factor (TF) MdbHLH3 at its Ser361 site in response to glucose. Furthermore, both the hexokinase_2 domain and signal peptide are crucial for the MdHXK1-mediated phosphorylation of MdbHLH3. Moreover, phosphorylation modification stabilized MdbHLH3 protein and enhanced its transcription of the anthocyanin biosynthesis genes, thereby increasing anthocyanin biosynthesis. Finally, a series of transgenic analyses in apple calli and fruits demonstrated that MdHXK1 controlled glucose-induced anthocyanin accumulation at least partially, if not completely, via regulating MdbHLH3. Overall, our findings provide new insights into the mechanism of the glucose sensor HXK1 modulation of anthocyanin accumulation, which occur by directly regulating the anthocyanin-related bHLH TFs in response to a glucose signal in plants.

  1. Phosphorylation of the exocyst protein Exo84 by TBK1 promotes insulin-stimulated GLUT4 trafficking.

    PubMed

    Uhm, Maeran; Bazuine, Merlijn; Zhao, Peng; Chiang, Shian-Huey; Xiong, Tingting; Karunanithi, Sheelarani; Chang, Louise; Saltiel, Alan R

    2017-03-21

    Insulin stimulates glucose uptake through the translocation of the glucose transporter GLUT4 to the plasma membrane. The exocyst complex tethers GLUT4-containing vesicles to the plasma membrane, a process that requires the binding of the G protein (heterotrimeric guanine nucleotide-binding protein) RalA to the exocyst complex. We report that upon activation of RalA, the protein kinase TBK1 phosphorylated the exocyst subunit Exo84. Knockdown of TBK1 blocked insulin-stimulated glucose uptake and GLUT4 translocation; knockout of TBK1 in adipocytes blocked insulin-stimulated glucose uptake; and ectopic overexpression of a kinase-inactive mutant of TBK1 reduced insulin-stimulated glucose uptake in 3T3-L1 adipocytes. The phosphorylation of Exo84 by TBK1 reduced its affinity for RalA and enabled its release from the exocyst. Overexpression of a kinase-inactive mutant of TBK1 blocked the dissociation of the TBK1/RalA/exocyst complex, and treatment of 3T3-L1 adipocytes with specific inhibitors of TBK1 reduced the rate of complex dissociation. Introduction of phosphorylation-mimicking or nonphosphorylatable mutant forms of Exo84 blocked insulin-stimulated GLUT4 translocation. Thus, these data indicate that TBK1 controls GLUT4 vesicle engagement and disengagement from the exocyst, suggesting that exocyst components not only constitute a tethering complex for the GLUT4 vesicle but also act as "gatekeepers" controlling vesicle fusion at the plasma membrane.

  2. Cyclin D1 promotes BRCA2-Rad51 interaction by restricting cyclin A/B-dependent BRCA2 phosphorylation.

    PubMed

    Chalermrujinanant, C; Michowski, W; Sittithumcharee, G; Esashi, F; Jirawatnotai, S

    2016-06-02

    BRCA2 has an important role in the maintenance of genome stability by interacting with RAD51 recombinase through its C-terminal domain. This interaction is abrogated by cyclin A-CDK2-mediated phosphorylation of BRCA2 at serine 3291 (Ser3291). Recently, we showed that cyclin D1 facilitates RAD51 recruitment to BRCA2-containing DNA repair foci, and that downregulation of cyclin D1 leads to inefficient homologous-mediated DNA repair. Here, we demonstrate that cyclin D1, via amino acids 20-90, interacts with the C-terminal domain of BRCA2, and that this interaction is increased in response to DNA damage. Interestingly, CDK4-cyclin D1 does not phosphorylate Ser3291. Instead, cyclin D1 bars cyclin A from the C-terminus of BRCA2, prevents cyclin A-CDK2-dependent Ser3291 phosphorylation and facilitates RAD51 binding to the C-terminal domain of BRCA2. These findings indicate that the interplay between cyclin D1 and other cyclins such as cyclin A regulates DNA integrity through RAD51 interaction with the BRCA2 C-terminal domain.

  3. Glucose Sensor MdHXK1 Phosphorylates and Stabilizes MdbHLH3 to Promote Anthocyanin Biosynthesis in Apple

    PubMed Central

    Hu, Da-Gang; Zhang, Quan-Yan; An, Jian-Ping; You, Chun-Xiang; Hao, Yu-Jin

    2016-01-01

    Glucose induces anthocyanin accumulation in many plant species; however, the molecular mechanism involved in this process remains largely unknown. Here, we found that apple hexokinase MdHXK1, a glucose sensor, was involved in sensing exogenous glucose and regulating anthocyanin biosynthesis. In vitro and in vivo assays suggested that MdHXK1 interacted directly with and phosphorylated an anthocyanin-associated bHLH transcription factor (TF) MdbHLH3 at its Ser361 site in response to glucose. Furthermore, both the hexokinase_2 domain and signal peptide are crucial for the MdHXK1-mediated phosphorylation of MdbHLH3. Moreover, phosphorylation modification stabilized MdbHLH3 protein and enhanced its transcription of the anthocyanin biosynthesis genes, thereby increasing anthocyanin biosynthesis. Finally, a series of transgenic analyses in apple calli and fruits demonstrated that MdHXK1 controlled glucose-induced anthocyanin accumulation at least partially, if not completely, via regulating MdbHLH3. Overall, our findings provide new insights into the mechanism of the glucose sensor HXK1 modulation of anthocyanin accumulation, which occur by directly regulating the anthocyanin-related bHLH TFs in response to a glucose signal in plants. PMID:27560976

  4. Phosphorylation/dephosphorylation of the repressor MDBP-2-H1 selectively affects the level of transcription from a methylated promoter in vitro.

    PubMed Central

    Bruhat, A; Jost, J P

    1996-01-01

    We have previously shown that in vivo estradiol-dependent dephosphorylation of MDBP-2-H1 (a member of the histone H1 family) correlates with the loss of in vitro preferential binding to methylated DNA. To study the effects of the phosphorylation/dephosphorylation of MDBP-2-H1 on the expression of the avian vitellogenin II gene, we optimised an in vitro transcription system using HeLa nuclear extracts. We show that in the absence of the phosphorylated form of MDBP-2-H1 from rooster, methylation of the vitellogenin II promoter does not affect the transcription. Addition of purified MDBP-2-H1 from rooster to the in vitro transcription system inhibits transcription more efficiently from a methylated than an unmethylated DNA template. Dephosphorylation of rooster MDBP-2-H1 by phosphatase treatment or estradiol treatment of rooster lead to the loss of inhibitory activity of the protein when added to the in vitro transcription assays. These findings indicate that the phosphorylation of MDBP-2-H1 is essential for the repression of the transcription. Taken together these results establish the relationship between the dephosphorylation of MDBP-2-H1 caused by estradiol, the down regulation of its binding activity to methylated DNA and the derepression of vitellogenin II transcription. PMID:8657560

  5. Plant Natural Product Formononetin Protects Rat Cardiomyocyte H9c2 Cells against Oxygen Glucose Deprivation and Reoxygenation via Inhibiting ROS Formation and Promoting GSK-3β Phosphorylation.

    PubMed

    Cheng, Yuanyuan; Xia, Zhengyuan; Han, Yifan; Rong, Jianhui

    2016-01-01

    The opening of mitochondrial permeability transition pore (mPTP) is a major cause of cell death in ischemia reperfusion injury. Based on our pilot experiments, plant natural product formononetin enhanced the survival of rat cardiomyocyte H9c2 cells during oxygen glucose deprivation (OGD) and reoxygenation. For mechanistic studies, we focused on two major cellular factors, namely, reactive oxygen species (ROS) and glycogen synthase kinase 3β (GSK-3β), in the regulation of mPTP opening. We found that formononetin suppressed the formation of ROS and superoxide in a concentration-dependent manner. Formononetin also rescued OGD/reoxygenation-induced loss of mitochondrial membrane integrity. Further studies suggested that formononetin induced Akt activation and GSK-3β (Ser9) phosphorylation, thereby reducing GSK-3β activity towards mPTP opening. PI3K and PKC inhibitors abolished the effects of formononetin on mPTP opening and GSK-3β phosphorylation. Immunoprecipitation experiments further revealed that formononetin increased the binding of phosphor-GSK-3β to adenine nucleotide translocase (ANT) while it disrupted the complex of ANT with cyclophilin D. Moreover, immunofluorescence revealed that phospho-GSK-3β (Ser9) was mainly deposited in the space between mitochondria and cell nucleus. Collectively, these results indicated that formononetin protected cardiomyocytes from OGD/reoxygenation injury via inhibiting ROS formation and promoting GSK-3β phosphorylation.

  6. Protein Kinase C (PKC)-promoted Endocytosis of Glutamate Transporter GLT-1 Requires Ubiquitin Ligase Nedd4-2-dependent Ubiquitination but Not Phosphorylation*

    PubMed Central

    García-Tardón, Noemí; González-González, Inmaculada M.; Martínez-Villarreal, Jaime; Fernández-Sánchez, Enrique; Giménez, Cecilio; Zafra, Francisco

    2012-01-01

    Glutamate transporter-1 (GLT-1) is the main glutamate transporter in the central nervous system, and its concentration severely decreases in neurodegenerative diseases. The number of transporters in the plasma membrane reflects the balance between their insertion and removal, and it has been reported that the regulated endocytosis of GLT-1 depends on its ubiquitination triggered by protein kinase C (PKC) activation. Here, we identified serine 520 of GLT-1 as the primary target for PKC-dependent phosphorylation, although elimination of this serine did not impair either GLT-1 ubiquitination or endocytosis in response to phorbol esters. In fact, we present evidence indicating that the ubiquitin ligase Nedd4-2 mediates the PKC-dependent ubiquitination and down-regulation of GLT-1. Overexpression of Nedd4-2 increased the ubiquitination of the transporter and promoted its degradation. Moreover, phorbol myristate acetate enhanced Nedd4-2 phosphorylation and the formation of GLT-1·Nedd4-2 complexes, whereas siRNA knockdown of Nedd4-2 prevented ubiquitination, endocytosis, and the concomitant decrease in GLT-1 activity triggered by PKC activation. These results indicate that GLT-1 endocytosis is independent of its phosphorylation and that Nedd4-2 mediates PKC-dependent down-regulation of the transporter. PMID:22505712

  7. Extracellular Signal-regulated Kinase Mediates Phosphorylation of Tropomyosin-1 to Promote Cytoskeleton Remodeling in Response to Oxidative Stress: Impact on Membrane Blebbing

    PubMed Central

    Houle, François; Rousseau, Simon; Morrice, Nick; Luc, Mario; Mongrain, Sébastien; Turner, Christopher E.; Tanaka, Sakae; Moreau, Pierre; Huot, Jacques

    2003-01-01

    Oxidative stress induces in endothelial cells a quick and transient coactivation of both stress-activated protein kinase-2/p38 and extracellular signal-regulated kinase (ERK) mitogen-activated protein kinases. We found that inhibiting the ERK pathway resulted, within 5 min of oxidative stress, in a misassembly of focal adhesions characterized by mislocalization of key proteins such as paxillin. The focal adhesion misassembly that followed ERK inhibition with the mitogen-activated protein kinase kinase (MEK) inhibitor PD098059 (2′-amino-3′-methoxyflavone) or with a kinase negative mutant of ERK in the presence of H2O2 resulted in a quick and intense membrane blebbing that was associated with important damage to the endothelium. We isolated by two-dimensional gel electrophoresis a PD098059-sensitive phosphoprotein of 38 kDa that we identified, by mass spectrometry, as tropomyosin-1. In fact, H2O2 induced a time-dependent phosphorylation of tropomyosin that was sensitive to inhibition by PD098059 and UO126 (1,4-diamino-2,3-dicyano-1,4-bis[2-aminophenylthio]butanediane). Tropomyosin phosphorylation was also induced by expression of a constitutively activated form of MEK1 (MEKCA), which confirms that its phosphorylation resulted from the activation of ERK. In unstimulated cells, tropomyosin-1 was found diffuse in the cells, whereas it quickly colocalized with actin and stress fibers upon stimulation of ERK by H2O2 or by expression of MEKCA. We propose that phosphorylation of tropomyosin-1 downstream of ERK by contributing to formation of actin filaments increases cellular contractility and promotes the formation of focal adhesions. Incidentally, ML-7 (1-[5iodonaphthalene-1-sulfonyl]homopiperazine, HCl), an inhibitor of cell contractility, inhibited phosphorylation of tropomyosin and blocked the formation of stress fibers and focal adhesions, which also led to membrane blebbing in the presence of oxidative stress. Our finding that tropomyosin-1 is phosphorylated

  8. Mammalian Polo-like kinase 1 (Plk1) promotes proper chromosome segregation by phosphorylating and delocalizing the PBIP1·CENP-Q complex from kinetochores.

    PubMed

    Park, Chi Hoon; Park, Jung-Eun; Kim, Tae-Sung; Kang, Young Hwi; Soung, Nak-Kyun; Zhou, Ming; Kim, Nam-Hyung; Bang, Jeong Kyu; Lee, Kyung S

    2015-03-27

    Mammalian Plk1 is critically required for proper M phase progression. Plk1 is self-recruited to prekinetochores/kinetochores by phosphorylating and binding to the Thr-78 motif of a kinetochore scaffold protein, PBIP1 (also called CENP-U/50), which forms a stable complex with another kinetochore component, CENP-Q. However, the mechanism regulating Plk1 localization to this site remains largely unknown. Here, we demonstrate that the PBIP1·CENP-Q complex became hyperphosphorylated and rapidly delocalized from kinetochores as cells entered mitosis. Plk1 phosphorylated the CENP-Q subunit of the PBIP1·CENP-Q complex at multiple sites, and mutation of nine Plk1-dependent phosphorylation sites to Ala (9A) enhanced CENP-Q association with chromatin and prolonged CENP-Q localization to kinetochores. Conversely, mutation of the nine sites to phospho-mimicking Asp/Glu (9D/E) residues dissociated CENP-Q from chromatin and kept the CENP-Q(9D/E) mutant from localizing to interphase prekinetochores. Strikingly, both the 9A and 9D/E mutants induced a defect in proper chromosome segregation, suggesting that both timely localization of the PBIP1·CENP-Q complex to prekinetochores and delocalization from kinetochores are critical for normal M phase progression. Notably, although Plk1 did not alter the level of PBIP1 and CENP-Q ubiquitination, Plk1-dependent phosphorylation and delocalization of these proteins from kinetochores appeared to indirectly lead to their degradation in the cytosol. Thus, we propose that Plk1 regulates the timing of the delocalization and ultimate destruction of the PBIP1·CENP-Q complex and that these processes are important not only for promoting Plk1-dependent mitotic progression, but also for resetting the timing of Plk1 recruitment to prekinetochores in the next cell cycle. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  9. Mammalian Polo-like Kinase 1 (Plk1) Promotes Proper Chromosome Segregation by Phosphorylating and Delocalizing the PBIP1·CENP-Q Complex from Kinetochores

    PubMed Central

    Park, Chi Hoon; Park, Jung-Eun; Kim, Tae-Sung; Kang, Young Hwi; Soung, Nak-Kyun; Zhou, Ming; Kim, Nam-Hyung; Bang, Jeong Kyu; Lee, Kyung S.

    2015-01-01

    Mammalian Plk1 is critically required for proper M phase progression. Plk1 is self-recruited to prekinetochores/kinetochores by phosphorylating and binding to the Thr-78 motif of a kinetochore scaffold protein, PBIP1 (also called CENP-U/50), which forms a stable complex with another kinetochore component, CENP-Q. However, the mechanism regulating Plk1 localization to this site remains largely unknown. Here, we demonstrate that the PBIP1·CENP-Q complex became hyperphosphorylated and rapidly delocalized from kinetochores as cells entered mitosis. Plk1 phosphorylated the CENP-Q subunit of the PBIP1·CENP-Q complex at multiple sites, and mutation of nine Plk1-dependent phosphorylation sites to Ala (9A) enhanced CENP-Q association with chromatin and prolonged CENP-Q localization to kinetochores. Conversely, mutation of the nine sites to phospho-mimicking Asp/Glu (9D/E) residues dissociated CENP-Q from chromatin and kept the CENP-Q(9D/E) mutant from localizing to interphase prekinetochores. Strikingly, both the 9A and 9D/E mutants induced a defect in proper chromosome segregation, suggesting that both timely localization of the PBIP1·CENP-Q complex to prekinetochores and delocalization from kinetochores are critical for normal M phase progression. Notably, although Plk1 did not alter the level of PBIP1 and CENP-Q ubiquitination, Plk1-dependent phosphorylation and delocalization of these proteins from kinetochores appeared to indirectly lead to their degradation in the cytosol. Thus, we propose that Plk1 regulates the timing of the delocalization and ultimate destruction of the PBIP1·CENP-Q complex and that these processes are important not only for promoting Plk1-dependent mitotic progression, but also for resetting the timing of Plk1 recruitment to prekinetochores in the next cell cycle. PMID:25670858

  10. Expression of a phosphorylated substrate domain of p130Cas promotes PyMT-induced c-Src-dependent murine breast cancer progression

    PubMed Central

    Zhao, Yingshe; Kumbrink, Joerg; Kirsch, Kathrin H.

    2013-01-01

    Elevated expression of p130Cas (Crk-associated substrate)/BCAR1 (breast cancer antiestrogen resistance 1) in human breast tumors is a marker of poor prognosis and poor overall survival. p130Cas is a downstream target of the tyrosine kinase c-Src. Signaling mediated by p130Cas through its phosphorylated substrate domain (SD) and interaction with effector molecules directly promotes tumor progression. We previously developed a constitutively phosphorylated p130Cas SD molecule, Src*/SD (formerly referred to as Src*/CasSD), which acts as decoy molecule and attenuates the transformed phenotype in v-crk-transformed murine fibroblasts and human breast cancer cells. To test the function of this molecule in vivo, we established mouse mammary tumor virus (MMTV)-long terminal repeat-Src*/SD transgenic mice in which mammary gland development and tumor formation were analyzed. Transgenic expression of the Src*/SD molecule under the MMTV-long terminal repeat promoter did not interfere with normal mammary gland development or induce tumors in mice observed for up to 11 months. To evaluate the effects of the Src*/SD molecule on tumor development in vivo, we utilized the MMTV-polyoma middle T-antigen (PyMT) murine breast cancer model that depends on c-Src. PyMT mice crossed with Src*/SD mice displayed accelerated tumor formation. The earlier onset of tumors can be explained by the interaction of the Src* domain with PyMT and targeting the fused phosphorylated SD to the membrane. At membrane compartments, it might integrate membrane-associated active signaling complexes leading to increased proliferation measured by phospho-Histone H3 staining. Although these results were unexpected, they emphasize the importance of preventing the membrane association of Src*/SD when employed as decoy molecule. PMID:23825155

  11. Expression of a phosphorylated substrate domain of p130Cas promotes PyMT-induced c-Src-dependent murine breast cancer progression.

    PubMed

    Zhao, Yingshe; Kumbrink, Joerg; Lin, Bor-Tyh; Bouton, Amy H; Yang, Shi; Toselli, Paul A; Kirsch, Kathrin H

    2013-12-01

    Elevated expression of p130Cas (Crk-associated substrate)/BCAR1 (breast cancer antiestrogen resistance 1) in human breast tumors is a marker of poor prognosis and poor overall survival. p130Cas is a downstream target of the tyrosine kinase c-Src. Signaling mediated by p130Cas through its phosphorylated substrate domain (SD) and interaction with effector molecules directly promotes tumor progression. We previously developed a constitutively phosphorylated p130Cas SD molecule, Src*/SD (formerly referred to as Src*/CasSD), which acts as decoy molecule and attenuates the transformed phenotype in v-crk-transformed murine fibroblasts and human breast cancer cells. To test the function of this molecule in vivo, we established mouse mammary tumor virus (MMTV)-long terminal repeat-Src*/SD transgenic mice in which mammary gland development and tumor formation were analyzed. Transgenic expression of the Src*/SD molecule under the MMTV-long terminal repeat promoter did not interfere with normal mammary gland development or induce tumors in mice observed for up to 11 months. To evaluate the effects of the Src*/SD molecule on tumor development in vivo, we utilized the MMTV-polyoma middle T-antigen (PyMT) murine breast cancer model that depends on c-Src. PyMT mice crossed with Src*/SD mice displayed accelerated tumor formation. The earlier onset of tumors can be explained by the interaction of the Src* domain with PyMT and targeting the fused phosphorylated SD to the membrane. At membrane compartments, it might integrate membrane-associated active signaling complexes leading to increased proliferation measured by phospho-Histone H3 staining. Although these results were unexpected, they emphasize the importance of preventing the membrane association of Src*/SD when employed as decoy molecule.

  12. PKC-ι promotes glioblastoma cell survival by phosphorylating and inhibiting BAD through a phosphatidylinositol 3-kinase pathway.

    PubMed

    Desai, S; Pillai, P; Win-Piazza, H; Acevedo-Duncan, M

    2011-06-01

    The focus of this research was to investigate the role of protein kinase C-iota (PKC-ι) in regulation of Bad, a pro-apoptotic BH3-only molecule of the Bcl-2 family in glioblastoma. Robust expression of PKC-ι is a hallmark of human glioma and benign and malignant meningiomas. The results were obtained from the two human glial tumor derived cell lines, T98G and U87MG. In these cells, PKC-ι co-localized and directly associated with Bad, as shown by immunofluorescence, immunoprecipitation, and Western blotting. Furthermore, in-vitro kinase activity assay showed that PKC-ι directly phosphorylated Bad at phospho specific residues, Ser-112, Ser-136 and Ser-155 which in turn induced inactivation of Bad and disruption of Bad/Bcl-XL dimer. Knockdown of PKC-ι by siRNA exhibited a corresponding reduction in Bad phosphorylation suggesting that PKC-ι may be a Bad kinase. PKC-ι knockdown also induced apoptosis in both the cell lines. Since, PKC-ι is an essential downstream mediator of the PI (3)-kinase, we hypothesize that glioma cell survival is mediated via a PI (3)-kinase/PDK1/PKC-ι/Bad pathway. Treatment with PI (3)-kinase inhibitors Wortmannin and LY294002, as well as PDK1 siRNA, inhibited PKC-ι activity and subsequent phosphorylation of Bad suggesting that PKC-ι regulates the activity of Bad in a PI (3)-kinase dependent manner. Thus, our data suggest that glioma cell survival occurs through a novel PI (3)-kinase/PDK1/PKC-ι/BAD mediated pathway.

  13. Low-dose interleukin-2 promotes STAT-5 phosphorylation, Treg survival and CTLA-4-dependent function in autoimmune liver diseases.

    PubMed

    Jeffery, H C; Jeffery, L E; Lutz, P; Corrigan, M; Webb, G J; Hirschfield, G M; Adams, D H; Oo, Y H

    2017-02-08

    CD4(+) CD25(high) CD127(low) forkhead box protein 3 (FoxP3(+) ) regulatory T cells (Treg ) are essential for the maintenance of peripheral tolerance. Impaired Treg function and an imbalance between effector and Tregs contribute to the pathogenesis of autoimmune diseases. We reported recently that the hepatic microenvironment is deficient in interleukin (IL)-2, a cytokine essential for Treg survival and function. Consequently, few liver-infiltrating Treg demonstrate signal transducer and activator of transcription-5 (STAT-5) phosphorylation. To establish the potential of IL-2 to enhance Treg therapy, we investigated the effects of very low dose Proleukin (VLDP) on the phosphorylation of STAT-5 and the subsequent survival and function of Treg and T effector cells from the blood and livers of patients with autoimmune liver diseases. VLDP, at less than 5 IU/ml, resulted in selective phosphorylation of STAT-5 in Treg but not effector T cells or natural killer cells and associated with increased expression of cytotoxic T lymphocyte antigen-4 (CTLA-4), FoxP3 and CD25 and the anti-apoptotic protein Bcl-2 in Treg with the greatest enhancement of regulatory phenotype in the effector memory Treg population. VLDP also maintained expression of the liver-homing chemokine receptor CXCR3. VLDP enhanced Treg function in a CTLA-4-dependent manner. These findings open new avenues for future VLDP cytokine therapy alone or in combination with clinical grade Treg in autoimmune liver diseases, as VLDP could not only enhance regulatory phenotype and functional property but also the survival of intrahepatic Treg .

  14. Novel roles for LIX1L in promoting cancer cell proliferation through ROS1-mediated LIX1L phosphorylation

    PubMed Central

    Nakamura, Satoki; Kahyo, Tomoaki; Tao, Hong; Shibata, Kiyoshi; Kurabe, Nobuya; Yamada, Hidetaka; Shinmura, Kazuya; Ohnishi, Kazunori; Sugimura, Haruhiko

    2015-01-01

    Herein, we report the characterization of Limb expression 1-like, (LIX1L), a putative RNA-binding protein (RBP) containing a double-stranded RNA binding motif, which is highly expressed in various cancer tissues. Analysis of MALDI-TOF/TOF mass spectrometry and RNA immunoprecipitation-sequencing of interacting proteins and the microRNAs (miRNAs) bound to LIX1L revealed that LIX1L interacts with proteins (RIOK1, nucleolin and PABPC4) and miRNAs (has-miRNA-520a-5p, −300, −216b, −326, −190a, −548b-3p, −7–5p and −1296) in HEK-293 cells. Moreover, the reduction of phosphorylated Tyr136 (pTyr136) in LIX1L through the homeodomain peptide, PY136, inhibited LIX1L-induced cell proliferation in vitro, and PY136 inhibited MKN45 cell proliferation in vivo. We also determined the miRNA-targeted genes and showed that was apoptosis induced through the reduction of pTyr136. Moreover, ROS1, HCK, ABL1, ABL2, JAK3, LCK and TYR03 were identified as candidate kinases responsible for the phosphorylation of Tyr136 of LIX1L. These data provide novel insights into the biological significance of LIX1L, suggesting that this protein might be an RBP, with implications for therapeutic approaches for targeting LIX1L in LIX1L-expressing cancer cells. PMID:26310847

  15. Aβ-Induced Drp1 phosphorylation through Akt activation promotes excessive mitochondrial fission leading to neuronal apoptosis.

    PubMed

    Kim, Dah Ihm; Lee, Ki Hoon; Gabr, Amr Ahmed; Choi, Gee Euhn; Kim, Jun Sung; Ko, So Hee; Han, Ho Jae

    2016-11-01

    Mitochondrial dysfunction is known as one of causative factors in Alzheimer's disease (AD), inducing neuronal cell death. Mitochondria regulate their functions through changing their morphology. The present work was undertaken to investigate whether Amyloid β (Aβ) affects mitochondrial morphology in neuronal cells to induce apoptosis. Aβ treatment induced not only the fragmentation of mitochondria but also neuronal apoptosis in association with an increase in caspase-9 and -3 activity. Calcium influx induced by Aβ up-regulated the activation of Akt through CaMKII resulting in changes to the phosphorylation level of Drp1 in a time-dependent manner. Translocation of Drp1 from the cytosol to mitochondria was blocked by CB-124005 (an Akt inhibitor). Recruitment of Drp1 to mitochondria led to ROS generation and mitochondrial fission, accompanied by dysfunction of mitochondria such as loss of membrane potential and ATP production. ROS generation and mitochondrial dysfunction by Aβ were attenuated when treated with Mdivi-1, a selective Drp1 inhibitor. Furthermore, the sustained Akt activation induced not only the fragmentation of mitochondria but also the activation of mTOR, eventually suppressing autophagy. Inhibition of autophagic clearance of Aβ led to increased ROS levels and aggravating mitochondrial defects, which were blocked by Rapamycin (an mTOR inhibitor). In conclusion, sustained phosphorylation of Akt by Aβ directly activates Drp1 and inhibits autophagy through the mTOR pathway. Together, these changes elicit abundant mitochondrial fragmentation resulting in ROS-mediated neuronal apoptosis.

  16. Dasatinib promotes paclitaxel-induced necroptosis in lung adenocarcinoma with phosphorylated caspase-8 by c-Src.

    PubMed

    Diao, Yan; Ma, Xiaobin; Min, WeiLi; Lin, Shuai; Kang, HuaFeng; Dai, ZhiJun; Wang, Xijing; Zhao, Yang

    2016-08-28

    Cisplatin and paclitaxel are considered to be the backbone of chemotherapy in lung adenocarcinoma. These agents show pleiotropic effects on cell death. However, the precise mechanisms remain unclear. The present study reported that phosphorylated caspase-8 at tyrosine 380 (p-Casp8) was characterized as a biomarker of chemoresistance to TP regimen (cisplatin and paclitaxel) in patients with resectable lung adenocarcinoma with significantly poorer 5-year disease-free survival (DFS) and overall survival (OS). Cisplatin killed lung adenocarcinoma cells regardless of c-Src-induced caspase-8 phosphorylation at tyrosine 380. Subsequently, we identified a novel mechanism by which paclitaxel induced necroptosis in lung adenocarcinoma cells that was dependent upon p-Casp8, receptor-interacting protein kinase 1 (RIPK1), and RIPK3. Moreover, dasatinib, a c-Src inhibitor, dephosphorylated caspase-8 to facilitate necroptosis, rather than apoptosis, in paclitaxel-treated p-Casp8-expressing lung adenocarcinoma cells. The data from our study revealed previously unrecognized roles of p-Casp8 as a positive effector in the initiation of necroptosis and as a negative effector in the repression of the interaction between RIPK1 and RIPK3. Moreover, these outcomes supported the need for further clinical studies with the goal of evaluating the efficacy of dasatinib plus paclitaxel in the treatment of lung adenocarcinoma. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  17. MST3 Kinase Phosphorylates TAO1/2 to Enable Myosin Va Function in Promoting Spine Synapse Development

    PubMed Central

    Ultanir, Sila K.; Yadav, Smita; Hertz, Nicholas T.; Oses-Prieto, Juan A.; Claxton, Suzanne; Burlingame, Alma L.; Shokat, Kevan M.; Jan, Lily Y.; Jan, Yuh-Nung

    2014-01-01

    Summary Mammalian Sterile 20 (Ste20)-like kinase 3 (MST3) is a ubiquitously expressed kinase capable of enhancing axon outgrowth. Whether and how MST3 kinase signaling might regulate development of dendritic filopodia and spine synapses is unknown. Through shRNA-mediated depletion of MST3 and kinase-dead MST3 expression in developing hippocampal cultures, we found that MST3 is necessary for proper filopodia, dendritic spine, and excitatory synapse development. Knockdown of MST3 in layer 2/3 pyramidal neurons via in utero electroporation also reduced spine density in vivo. Using chemical genetics, we discovered thirteen candidate MST3 substrates and identified the phosphorylation sites. Among the identified MST3 substrates, TAO kinases regulate dendritic filopodia and spine development, similar to MST3. Furthermore, using stable isotope labeling by amino acids in culture (SILAC), we show that phosphorylated TAO1/2 associates with Myosin Va and is necessary for its dendritic localization, thus revealing a mechanism for excitatory synapse development in the mammalian CNS. PMID:25456499

  18. MST3 kinase phosphorylates TAO1/2 to enable Myosin Va function in promoting spine synapse development.

    PubMed

    Ultanir, Sila K; Yadav, Smita; Hertz, Nicholas T; Oses-Prieto, Juan A; Claxton, Suzanne; Burlingame, Alma L; Shokat, Kevan M; Jan, Lily Y; Jan, Yuh-Nung

    2014-12-03

    Mammalian Sterile 20 (Ste20)-like kinase 3 (MST3) is a ubiquitously expressed kinase capable of enhancing axon outgrowth. Whether and how MST3 kinase signaling might regulate development of dendritic filopodia and spine synapses is unknown. Through shRNA-mediated depletion of MST3 and kinase-dead MST3 expression in developing hippocampal cultures, we found that MST3 is necessary for proper filopodia, dendritic spine, and excitatory synapse development. Knockdown of MST3 in layer 2/3 pyramidal neurons via in utero electroporation also reduced spine density in vivo. Using chemical genetics, we discovered thirteen candidate MST3 substrates and identified the phosphorylation sites. Among the identified MST3 substrates, TAO kinases regulate dendritic filopodia and spine development, similar to MST3. Furthermore, using stable isotope labeling by amino acids in culture (SILAC), we show that phosphorylated TAO1/2 associates with Myosin Va and is necessary for its dendritic localization, thus revealing a mechanism for excitatory synapse development in the mammalian CNS.

  19. AGE/RAGE/Akt pathway contributes to prostate cancer cell proliferation by promoting Rb phosphorylation and degradation.

    PubMed

    Bao, Ji-Ming; He, Min-Yi; Liu, Ya-Wei; Lu, Yong-Jie; Hong, Ying-Qia; Luo, Hai-Hua; Ren, Zhong-Lu; Zhao, Shan-Chao; Jiang, Yong

    2015-01-01

    Metabolomic research has revealed that metabolites play an important role in prostate cancer development and progression. Previous studies have suggested that prostate cancer cell proliferation is induced by advanced glycation end products (AGEs) exposure, but the mechanism of this induction remains unknown. This study investigated the molecular mechanisms underlying the proliferative response of prostate cancer cell to the interaction of AGEs and the receptor for advanced glycation end products (RAGE). To investigate this mechanism, we used Western blotting to evaluate the responses of the retinoblastoma (Rb), p-Rb and PI3K/Akt pathway to AGEs stimulation. We also examined the effect of knocking down Rb and blocking the PI3K/Akt pathway on AGEs induced PC-3 cell proliferation. Our results indicated that AGE-RAGE interaction enhanced Rb phosphorylation and subsequently decreased total Rb levels. Bioinformatics analysis further indicated a negative correlation between RAGE and RB1 expression in prostate cancer tissue. Furthermore, we observed that AGEs stimulation activated the PI3K/Akt signaling pathway and that blocking PI3K/Akt signaling abrogated AGEs-induced cell proliferation. We report, for the first time, that AGE-RAGE interaction enhances prostate cancer cell proliferation by phosphorylation of Rb via the PI3K/Akt signaling pathway.

  20. Brachytherapy in the Treatment of Cholangiocarcinoma

    SciTech Connect

    Shinohara, Eric T.; Guo Mengye; Mitra, Nandita; Metz, James M.

    2010-11-01

    Purpose: To examine the role of brachytherapy in the treatment of cholangiocarcinomas in a relatively large group of patients. Methods and Materials: Using the Surveillance, Epidemiology and End Results database, a total of 193 patients with cholangiocarcinoma treated with brachytherapy were identified for the period 1988-2003. The primary analysis compared patients treated with brachytherapy (with or without external-beam radiation) with those who did not receive radiation. To try to account for confounding variables, propensity score and sensitivity analyses were used. Results: There was a significant difference between patients who received radiation (n = 193) and those who did not (n = 6859) with regard to surgery (p < 0.0001), race (p < 0.0001), stage (p < 0.0001), and year of diagnosis (p <0.0001). Median survival for patients treated with brachytherapy was 11 months (95% confidence interval [CI] 9-13 months), compared with 4 months for patients who received no radiation (p < 0.0001). On multivariable analysis (hazard ratio [95% CI]) brachytherapy (0.79 [0.66-0.95]), surgery (0.50 [0.46-0.53]), year of diagnosis (1998-2003: 0.66 [0.60-0.73]; 1993-1997: (0.96 [0.89-1.03; NS], baseline 1988-1992), and extrahepatic disease (0.84 [0.79-0.89]) were associated with better overall survival. Conclusions: To the authors' knowledge, this is the largest dataset reported for the treatment of cholangiocarcinomas with brachytherapy. The results of this retrospective analysis suggest that brachytherapy may improve overall survival. However, because of the limitations of the Surveillance, Epidemiology and End Results database, these results should be interpreted cautiously, and future prospective studies are needed.

  1. Positron emission tomography (PET) for cholangiocarcinoma

    PubMed Central

    Breitenstein, S.; Apestegui, C.

    2008-01-01

    The combination of positron emission tomography (PET) with computed tomography (PET-CT) provides simultaneous metabolic and anatomic information on tumors in the same imaging session. Sensitivity of PET/PET-CT is higher for intrahepatic (>90%) than for extrahepatic cholangiocarcinoma (CCA) (about 60%). The detection rate of distant metastasis is 100%. PET, and particularly PET-CT, improves the results and impacts on the oncological management in CCA compared with other imaging modalities. Therefore, PET-CT is recommended in the preoperative staging of intrahepatic (strength of recommendation: moderate) and extrahepatic (strength of recommendation: low) CCA. PMID:18773069

  2. [Occupational cholangiocarcinoma in a printer that responded to neoadjuvant chemoradiotherapy].

    PubMed

    Nakagawa, Kei; Katayose, Yu; Ishida, Kazuyuki; Hayashi, Hiroki; Morikawa, Takanori; Yoshida, Hiroshi; Motoi, Fuyuhiko; Naitoh, Takeshi; Kubo, Shoji; Unno, Michiaki

    2015-07-01

    A 42-year-old man working at a printing company was referred to our hospital for examination and treatment of icterus. We diagnosed resectable hilar cholangiocarcinoma and provided neoadjuvant chemoradiotherapy, extended right hepatectomy, and extrahepatic bile duct resection. A detailed history revealed that he had used 1,2-dichloropropane as part of his work as an offset colour proof-printer, and he has subsequently been recognized as having occupational cholangiocarcinoma. He has survived without recurrence for more than 2 and half years since the liver resection. In the present report, we describe our valuable experience of neoadjuvant chemoradiotherapy for occupational cholangiocarcinoma.

  3. Ras-activated RSK1 phosphorylates EBP50 to regulate its nuclear localization and promote cell proliferation.

    PubMed

    Lim, Hooi Cheng; Jou, Tzuu-Shuh

    2016-03-01

    Differential subcellular localization of EBP50 leads to its controversial role in cancer biology either as a tumor suppressor when it resides at the membrane periphery, or a tumor facilitator at the nucleus. However, the mechanism behind nuclear localization of EBP50 remains unclear. A RNA interference screening identified the downstream effector of the Ras-ERK cascade, RSK1, as the molecule unique for nuclear transport of EBP50. RSK1 binds to EBP50 and phosphorylates it at a conserved threonine residue at position 156 (T156) under the regulation of growth factor. Mutagenesis experiments confirmed the significance of T156 residue in nuclear localization of EBP50, cellular proliferation, and oncogenic transformation. Our study sheds light on a possible therapeutic strategy targeting at this aberrant nuclear expression of EBP50 without affecting the normal physiological function of EBP50 at other subcellular localization.

  4. Phosphorylation by Casein Kinase I Promotes the Turnover of the Mdm2 Oncoprotein via the SCFβ-TRCP Ubiquitin Ligase

    PubMed Central

    Inuzuka, Hiroyuki; Tseng, Alan; Gao, Daming; Zhai, Bo; Zhang, Qing; Shaik, Shavali; Wan, Lixin; Ang, Xiaolu L.; Mock, Caroline; Yin, Haoqiang; Stommel, Jayne M.; Gygi, Steven; Lahav, Galit; Asara, John; Jim Xiao, Zhi-Xiong; Kaelin, William G.; Harper, J. Wade; Wei, Wenyi

    2010-01-01

    Summary Mdm2 is the major negative regulator of the p53 pathway. Here we report that Mdm2 is rapidly degraded after DNA damage and that phosphorylation of Mdm2 by Casein Kinase I (CKI) at multiple sites triggers its interaction with, and subsequent ubiquitination and destruction, by SCFβ-TRCP. Inactivation of either β-TRCP or CKI results in accumulation of Mdm2 and decreased p53 activity, and resistance to apoptosis induced by DNA damaging-agents. Moreover, SCFβ-TRCP-dependent Mdm2 turnover also contributes to the control of repeated p53 pulses in response to persistent DNA damage. Our results provide insight into the signaling pathways controlling Mdm2 destruction and further suggest that compromised regulation of Mdm2 results in attenuated p53 activity, thereby facilitating tumor progression. PMID:20708156

  5. Proteinase-activated receptor 2 (PAR(2)) in cholangiocarcinoma (CCA) cells: effects on signaling and cellular level.

    PubMed

    Kaufmann, Roland; Hascher, Alexander; Mussbach, Franziska; Henklein, Petra; Katenkamp, Kathrin; Westermann, Martin; Settmacher, Utz

    2012-12-01

    In this study, we demonstrate functional expression of the proteinase-activated receptor 2 (PAR(2)), a member of a G-protein receptor subfamily in primary cholangiocarcinoma (PCCA) cell cultures. Treatment of PCCA cells with the serine proteinase trypsin and the PAR(2)-selective activating peptide, furoyl-LIGRLO-NH(2), increased migration across a collagen membrane barrier. This effect was inhibited by a PAR(2)-selective pepducin antagonist peptide (P2pal-18S) and it was also blocked with the Met receptor tyrosine kinase (Met) inhibitors SU 11274 and PHA 665752, the MAPKinase inhibitors PD 98059 and SL 327, and the Stat3 inhibitor Stattic. The involvement of Met, p42/p44 MAPKinases and Stat3 in PAR(2)-mediated PCCA cell signaling was further supported by the findings that trypsin and the PAR(2)-selective agonist peptide, 2-furoyl-LIGRLO-NH(2), stimulated activating phosphorylation of these signaling molecules in cholangiocarcinoma cells. With our results, we provide a novel signal transduction module in cholangiocarcinoma cell migration involving PAR(2)-driven activation of Met, p42/p44 MAPKinases and Stat3.

  6. The Prolyl Isomerase Pin1 Promotes the Herpesvirus-Induced Phosphorylation-Dependent Disassembly of the Nuclear Lamina Required for Nucleocytoplasmic Egress

    PubMed Central

    Milbradt, Jens; Hutterer, Corina; Bahsi, Hanife; Wagner, Sabrina; Sonntag, Eric; Kaufer, Benedikt B.; Mori, Yasuko; Sticht, Heinrich; Fossen, Torgils; Marschall, Manfred

    2016-01-01

    The nuclear lamina lines the inner nuclear membrane providing a structural framework for the nucleus. Cellular processes, such as nuclear envelope breakdown during mitosis or nuclear export of large ribonucleoprotein complexes, are functionally linked to the disassembly of the nuclear lamina. In general, lamina disassembly is mediated by phosphorylation, but the precise molecular mechanism is still not completely understood. Recently, we suggested a novel mechanism for lamina disassembly during the nuclear egress of herpesviral capsids which involves the cellular isomerase Pin1. In this study, we focused on mechanistic details of herpesviral nuclear replication to demonstrate the general importance of Pin1 for lamina disassembly. In particular, Ser22-specific lamin phosphorylation consistently generates a Pin1-binding motif in cells infected with human and animal alpha-, beta-, and gammaherpesviruses. Using nuclear magnetic resonance spectroscopy, we showed that binding of Pin1 to a synthetic lamin peptide induces its cis/trans isomerization in vitro. A detailed bioinformatic evaluation strongly suggests that this structural conversion induces large-scale secondary structural changes in the lamin N-terminus. Thus, we concluded that a Pin1-induced conformational change of lamins may represent the molecular trigger responsible for lamina disassembly. Consistent with this concept, pharmacological inhibition of Pin1 activity blocked lamina disassembly in herpesvirus-infected fibroblasts and consequently impaired virus replication. In addition, a phospho-mimetic Ser22Glu lamin mutant was still able to form a regular lamina structure and overexpression of a Ser22-phosphorylating kinase did not induce lamina disassembly in Pin1 knockout cells. Intriguingly, this was observed in absence of herpesvirus infection proposing a broader importance of Pin1 for lamina constitution. Thus, our results suggest a functional model of similar events leading to disassembly of the nuclear

  7. Suppression of 5'-nucleotidase enzymes promotes AMP-activated protein kinase (AMPK) phosphorylation and metabolism in human and mouse skeletal muscle.

    PubMed

    Kulkarni, Sameer S; Karlsson, Håkan K R; Szekeres, Ferenc; Chibalin, Alexander V; Krook, Anna; Zierath, Juleen R

    2011-10-07

    The 5'-nucleotidase (NT5) family of enzyme dephosphorylates non-cyclic nucleoside monophosphates to produce nucleosides and inorganic phosphates. We hypothesized that gene silencing of NT5 enzymes to increase the intracellular availability of AMP would increase AMP-activated protein kinase (AMPK) activity and metabolism. We determined the role of cytosolic NT5 in metabolic responses linked to the development of insulin resistance in obesity and type 2 diabetes. Using siRNA to silence NT5C2 expression in cultured human myotubes, we observed a 2-fold increase in the AMP/ATP ratio, a 2.4-fold increase in AMPK phosphorylation (Thr(172)), and a 2.8-fold increase in acetyl-CoA carboxylase phosphorylation (Ser(79)) (p < 0.05). siRNA silencing of NT5C2 expression increased palmitate oxidation by 2-fold in the absence and by 8-fold in the presence of 5-aminoimidazole-4-carboxamide 1-β-d-ribofuranoside. This was paralleled by an increase in glucose transport and a decrease in glucose oxidation, incorporation into glycogen, and lactate release from NT5C2-depleted myotubes. Gene silencing of NT5C1A by shRNA injection and electroporation in mouse tibialis anterior muscle reduced protein content (60%; p < 0.05) and increased phosphorylation of AMPK (60%; p < 0.05) and acetyl-CoA carboxylase (50%; p < 0.05) and glucose uptake (20%; p < 0.05). Endogenous expression of NT5C enzymes inhibited basal lipid oxidation and glucose transport in skeletal muscle. Reduction of 5'-nucleotidase expression or activity may promote metabolic flexibility in type 2 diabetes.

  8. JMJD3 promotes SAHF formation in senescent WI38 cells by triggering an interplay between demethylation and phosphorylation of RB protein.

    PubMed

    Zhao, L; Zhang, Y; Gao, Y; Geng, P; Lu, Y; Liu, X; Yao, R; Hou, P; Liu, D; Lu, J; Huang, B

    2015-10-01

    Primary human fibroblasts undergoing oncogene-induced or replicative senescence are known to form senescence-associated heterochromatin foci (SAHF), which can stabilize the state of senescence. The retinoblastoma (RB) protein has an important role in SAHF; cells that lack active RB pathway fail to form SAHF. It has been known that the posttranslational modifications of RB, for example, phosphorylation, regulate its function. To date, whether methylation of RB impacts on the SAHF formation is unknown. Here we report that JMJD3, a histone demethylase catalyzing the tri-methylation of H3K27 (H3K27me3), can demethylate the non-histone protein RB at the lysine810 residue (K810), which is a target of the methyltransferase Set7/9. We detected a significant upregulation of JMJD3 during cellular senescence and SAHF formation in WI38 cells induced by H-RasV(12), and we found that ectopic expression of JMJD3 promoted cellular senescence and SAHF formation in WI38 cells. Furthermore, during the process of SAHF assembly, JMJD3 was transported to the cytoplasm and interacted with RB through its demethylase domain JmjC. Significantly, our data demonstrated that the JMJD3-mediated demethylation of RB at K810 impeded the interaction of RB with the protein kinase CDK4 and resulted in reduced level of phosphorylation of RB at Serine807/811 (S807/811), implicating an important role of the interplay between the demethylation and phosphorylation of RB in SAHF assembly. This study highlights the role of JMJD3 as a novel inducer of SAHF formation through demethylating RB and provides new insights into the mechanisms of cellular senescence and SAHF assembly.

  9. Aberrant Phosphorylation of SMAD4 Thr277-Mediated USP9x-SMAD4 Interaction by Free Fatty Acids Promotes Breast Cancer Metastasis.

    PubMed

    Wu, Yong; Yu, Xiaoting; Yi, Xianghua; Wu, Ke; Dwabe, Sami; Atefi, Mohammad; Elshimali, Yahya; Kemp, Kevin T; Bhat, Kruttika; Haro, Jesse; Sarkissyan, Marianna; Vadgama, Jaydutt V

    2017-03-15

    Obesity increases the risk of distant metastatic recurrence and reduces breast cancer survival. However, the mechanisms behind this pathology and identification of relevant therapeutic targets are poorly defined. Plasma free fatty acids (FFA) levels are elevated in obese individuals. Here we report that TGFβ transiently activates ERK and subsequently phosphorylates SMAD4 at Thr277, which facilitates a SMAD4-USP9x interaction, SMAD4 nuclear retention, and stimulates TGFβ/SMAD3-mediated transcription of Twist and Snail. USP9x inhibited the E3 ubiquitin-protein ligase TIF1γ from binding and monoubiquitinating SMAD4, hence maintaining the SMAD4 nuclear retention. FFA further facilitated TGFβ-induced ERK activation, SMAD4 phosphorylation, and nuclear retention, promoting TGFβ-dependent cancer progression. Inhibition of ERK and USP9x suppressed obesity-induced metastasis. In addition, clinical data indicated that phospho-ERK and -SMAD4 levels correlate with activated TGFβ signaling and metastasis in overweight/obese patient breast cancer specimens. Altogether, we demonstrate the vital interaction of USP9x and SMAD4 for governing TGFβ signaling and dyslipidemia-induced aberrant TGFβ activation during breast cancer metastasis. Cancer Res; 77(6); 1383-94. ©2017 AACR. ©2017 American Association for Cancer Research.

  10. Hyperinsulinemia enhances interleukin-17-induced inflammation to promote prostate cancer development in obese mice through inhibiting glycogen synthase kinase 3-mediated phosphorylation and degradation of interleukin-17 receptor.

    PubMed

    Liu, Sen; Zhang, Qiuyang; Chen, Chong; Ge, Dongxia; Qu, Yine; Chen, Rongyi; Fan, Yi-Ming; Li, Nan; Tang, Wendell W; Zhang, Wensheng; Zhang, Kun; Wang, Alun R; Rowan, Brian G; Hill, Steven M; Sartor, Oliver; Abdel-Mageed, Asim B; Myers, Leann; Lin, Qishan; You, Zongbing

    2016-03-22

    Interleukin-17 (IL-17) plays important roles in inflammation, autoimmune diseases, and some cancers. Obese people are in a chronic inflammatory state with increased serum levels of IL-17, insulin, and insulin-like growth factor 1 (IGF1). How these factors contribute to the chronic inflammatory status that promotes development of aggressive prostate cancer in obese men is largely unknown. We found that, in obese mice, hyperinsulinemia enhanced IL-17-induced expression of downstream proinflammatory genes with increased levels of IL-17 receptor A (IL-17RA), resulting in development of more invasive prostate cancer. Glycogen synthase kinase 3 (GSK3) constitutively bound to and phosphorylated IL-17RA at T780, leading to ubiquitination and proteasome-mediated degradation of IL-17RA, thus inhibiting IL-17-mediated inflammation. IL-17RA phosphorylation was reduced, while the IL-17RA levels were increased in the proliferative human prostate cancer cells compared to the normal cells. Insulin and IGF1 enhanced IL-17-induced inflammatory responses through suppressing GSK3, which was shown in the cultured cell lines in vitro and obese mouse models of prostate cancer in vivo. These findings reveal a mechanism underlying the intensified inflammation in obesity and obesity-associated development of aggressive prostate cancer, suggesting that targeting GSK3 may be a potential therapeutic approach to suppress IL-17-mediated inflammation in the prevention and treatment of prostate cancer, particularly in obese men.

  11. Hyperinsulinemia enhances interleukin-17-induced inflammation to promote prostate cancer development in obese mice through inhibiting glycogen synthase kinase 3-mediated phosphorylation and degradation of interleukin-17 receptor

    PubMed Central

    Chen, Chong; Ge, Dongxia; Qu, Yine; Chen, Rongyi; Fan, Yi-Ming; Li, Nan; Tang, Wendell W.; Zhang, Wensheng; Zhang, Kun; Wang, Alun R.; Rowan, Brian G.; Hill, Steven M.; Sartor, Oliver; Abdel, Asim B.; Myers, Leann; Lin, Qishan; You, Zongbing

    2016-01-01

    Interleukin-17 (IL-17) plays important roles in inflammation, autoimmune diseases, and some cancers. Obese people are in a chronic inflammatory state with increased serum levels of IL-17, insulin, and insulin-like growth factor 1 (IGF1). How these factors contribute to the chronic inflammatory status that promotes development of aggressive prostate cancer in obese men is largely unknown. We found that, in obese mice, hyperinsulinemia enhanced IL-17-induced expression of downstream proinflammatory genes with increased levels of IL-17 receptor A (IL-17RA), resulting in development of more invasive prostate cancer. Glycogen synthase kinase 3 (GSK3) constitutively bound to and phosphorylated IL-17RA at T780, leading to ubiquitination and proteasome-mediated degradation of IL-17RA, thus inhibiting IL-17-mediated inflammation. IL-17RA phosphorylation was reduced, while the IL-17RA levels were increased in the proliferative human prostate cancer cells compared to the normal cells. Insulin and IGF1 enhanced IL-17-induced inflammatory responses through suppressing GSK3, which was shown in the cultured cell lines in vitro and obese mouse models of prostate cancer in vivo. These findings reveal a mechanism underlying the intensified inflammation in obesity and obesity-associated development of aggressive prostate cancer, suggesting that targeting GSK3 may be a potential therapeutic approach to suppress IL-17-mediated inflammation in the prevention and treatment of prostate cancer, particularly in obese men. PMID:26871944

  12. Anticancer drugs induce hypomethylation of the acetylcholinesterase promoter via a phosphorylated-p38-DNMT1-AChE pathway in apoptotic hepatocellular carcinoma cells.

    PubMed

    Xi, Qiliang; Gao, Ning; Yang, Yang; Ye, Weiyuan; Zhang, Bo; Wu, Jun; Jiang, Gening; Zhang, Xuejun

    2015-11-01

    Apoptosis, also known as programmed cell death, plays an essential role in eliminating excessive, damaged or harmful cells. Previous work has demonstrated that anticancer drugs induce cell apoptosis by inducing cytotoxicity. In recent years, several reports demonstrated modulated expression of DNA methyltransferases 1 (DNMT1) and acetylcholinesterase (AChE) in a variety of tumors. In this study, we showed that the expression of DNMT1 was decreased and the methylation of CpGs in the promoter of AChE was reduced in anticancer drugs-induced apoptotic hepatocellular carcinoma cells. Silencing of DNMT1 expression by AZA or RNA interference (RNAi) restored AChE production and inhibition of AChE expression by RNAi protected HCC cells from anticancer drugs-induced apoptosis. Furthermore, we demonstrated that the regulation of AChE by DNMT1 was involved in the phosphorylated p38 pathway in anticancer drugs-induced apoptosis. In addition, immunohistochemical staining showed that P-p38, DNMT1 and AChE were aberrantly expressed in a subset of HCC tumors. Taken together, we demonstrated the regulation of AChE by DNMT1 and further, we found that this regulation was involved in the phosphorylated p38 pathway in anticancer drugs-induced apoptosis.

  13. The Myc Transactivation Domain Promotes Global Phosphorylation of the RNA Polymerase II Carboxy-Terminal Domain Independently of Direct DNA Binding▿ †

    PubMed Central

    Cowling, Victoria H.; Cole, Michael D.

    2007-01-01

    Myc is a transcription factor which is dependent on its DNA binding domain for transcriptional regulation of target genes. Here, we report the surprising finding that Myc mutants devoid of direct DNA binding activity and Myc target gene regulation can rescue a substantial fraction of the growth defect in myc−/− fibroblasts. Expression of the Myc transactivation domain alone induces a transcription-independent elevation of the RNA polymerase II (Pol II) C-terminal domain (CTD) kinases cyclin-dependent kinase 7 (CDK7) and CDK9 and a global increase in CTD phosphorylation. The Myc transactivation domain binds to the transcription initiation sites of these promoters and stimulates TFIIH binding in an MBII-dependent manner. Expression of the Myc transactivation domain increases CDK mRNA cap methylation, polysome loading, and the rate of translation. We find that some traditional Myc transcriptional target genes are also regulated by this Myc-driven translation mechanism. We propose that Myc transactivation domain-driven RNA Pol II CTD phosphorylation has broad effects on both transcription and mRNA metabolism. PMID:17242204

  14. The eIF2α serine 51 phosphorylation-ATF4 arm promotes HIPPO signaling and cell death under oxidative stress

    PubMed Central

    Rajesh, Kamindla; Kazimierczak, Urszula; Papadakis, Andreas I.; Deng, Zhilin; Wang, Shuo; Kuninaka, Shinji; Koromilas, Antonis E.

    2016-01-01

    The HIPPO pathway is an evolutionary conserved regulator of organ size that controls both cell proliferation and death. This pathway has an important role in mediating cell death in response to oxidative stress through the inactivation of Yes-associated protein (YAP) and inhibition of anti-oxidant gene expression. Cells exposed to oxidative stress induce the phosphorylation of the alpha (α) subunit of the translation initiation factor eIF2 at serine 51 (eIF2αP), a modification that leads to the general inhibition of mRNA translation initiation. Under these conditions, increased eIF2αP facilitates the mRNA translation of activating transcription factor 4 (ATF4), which mediates either cell survival and adaptation or cell death under conditions of severe stress. Herein, we demonstrate a functional connection between the HIPPO and eIF2αP-ATF4 pathways under oxidative stress. We demonstrate that ATF4 promotes the stabilization of the large tumor suppressor 1 (LATS1), which inactivates YAP by phosphorylation. ATF4 inhibits the expression of NEDD4.2 and WWP1 mRNAs under pro-oxidant conditions, which encode ubiquitin ligases mediating the proteasomal degradation of LATS1. Increased LATS1 stability is required for the induction of cell death under oxidative stress. Our data reveal a previously unidentified ATF4-dependent pathway in the induction of cell death under oxidative stress via the activation of LATS1 and HIPPO pathway. PMID:27409837

  15. Paxillin promotes colorectal tumor invasion and poor patient outcomes via ERK-mediated stabilization of Bcl-2 protein by phosphorylation at Serine 87.

    PubMed

    Huang, Chi-Chou; Wu, De-Wei; Lin, Po-Lin; Lee, Huei

    2015-04-20

    Stabilization of Bcl-2 protein by paxillin (PXN)-mediated ERK activation was recently reported to cause an unfavorable response to 5-Fluorouracil-based chemotherapy. Here, we present evidence from cell and animal models to demonstrate that stabilization of Bcl-2 protein by phosphorylation at Serine 87 (pBcl-2-S87) via PXN-mediated ERK activation is responsible for cancer cell invasiveness and occurs via upregulation of MMP2 expression. Immunostainings of 190 tumors resected from colorectal cancer patients indicated that PXN expression was positively correlated with Bcl-2, pBcl-2-S87, and MMP2 expression. A positive correlation of pBcl-2-S87 with Bcl-2 and MMP2 was also observed in this study population. Patients with high PXN, Bcl-2, pBcl-2-S87, and MMP2 had poor overall survival (OS) and shorter relapse free survival (RFS). In conclusion, PXN promotes Bcl-2 phosphorylation at Serine 87 via PXN-mediated ERK activation, and its stabilization associated with increased tumor formation efficacy in mice and poor patient outcome in colorectal cancer patients.

  16. Formin follows function: a muscle-specific isoform of FHOD3 is regulated by CK2 phosphorylation and promotes myofibril maintenance

    PubMed Central

    Iskratsch, Thomas; Lange, Stephan; Dwyer, Joseph; Kho, Ay Lin; dos Remedios, Cris

    2010-01-01

    Members of the formin family are important for actin filament nucleation and elongation. We have identified a novel striated muscle–specific splice variant of the formin FHOD3 that introduces a casein kinase 2 (CK2) phosphorylation site. The specific targeting of muscle FHOD3 to the myofibrils in cardiomyocytes is abolished in phosphomutants or by the inhibition of CK2. Phosphorylation of muscle FHOD3 also prevents its interaction with p62/sequestosome 1 and its recruitment to autophagosomes. Furthermore, we show that muscle FHOD3 efficiently promotes the polymerization of actin filaments in cardiomyocytes and that the down-regulation of its expression severely affects myofibril integrity. In murine and human cardiomyopathy, we observe reduced FHOD3 expression with a concomitant isoform switch and change of subcellular targeting. Collectively, our data suggest that a muscle-specific isoform of FHOD3 is required for the maintenance of the contractile structures in heart muscle and that its function is regulated by posttranslational modification. PMID:21149568

  17. Cholangiocarcinoma with metastasis in a captive Adelie penguin (Pygoscelis adeliae).

    PubMed

    Renner, M S; Zaias, J; Bossart, G D

    2001-09-01

    A captive male Adelie penguin (Pygoscelis adeliae), wild caught in 1976, died unexpectedly. Necropsy revealed cholangiocarcinoma with metastases to lung, pancreas, mesentery, and cloaca, the first known case of a penguin hepatic tumor.

  18. Cholecystokinin-Mediated RhoGDI Phosphorylation via PKCα Promotes both RhoA and Rac1 Signaling

    PubMed Central

    Sabbatini, Maria Eugenia; Williams, John A.

    2013-01-01

    RhoA and Rac1 have been implicated in the mechanism of CCK-induced amylase secretion from pancreatic acini. In all cell types studied to date, inactive Rho GTPases are present in the cytosol bound to the guanine nucleotide dissociation inhibitor RhoGDI. Here, we identified the switch mechanism regulating RhoGDI1-Rho GTPase dissociation and RhoA translocation upon CCK stimulation in pancreatic acini. We found that both Gα13 and PKC, independently, regulate CCK-induced RhoA translocation and that the PKC isoform involved is PKCα. Both RhoGDI1 and RhoGDI3, but not RhoGDI2, are expressed in pancreatic acini. Cytosolic RhoA and Rac1 are associated with RhoGDI1, and CCK-stimulated PKCα activation releases the complex. Overexpression of RhoGDI1, by binding RhoA, inhibits its activation, and thereby, CCK-induced apical amylase secretion. RhoA translocation is also inhibited by RhoGDI1. Inactive Rac1 influences CCK-induced RhoA activation by preventing RhoGDI1 from binding RhoA. By mutational analysis we found that CCK-induced PKCα phosphorylation on RhoGDI1 at Ser96 releases RhoA and Rac1 from RhoGDI1 to facilitate Rho GTPases signaling. PMID:23776598

  19. TOPK promotes lung cancer resistance to EGFR tyrosine kinase inhibitors by phosphorylating and activating c-Jun

    PubMed Central

    Wang, Tao; Wang, Ting; Niu, Mengjie; Zhang, Shengli; Jia, Lintao; Li, Shengqing

    2016-01-01

    Tyrosine kinase inhibitors (TKIs) targeting the epidermal growth factor receptor (EGFR) have shown promising clinical efficacy in non-squamous non-small cell lung cancer (NSCLC); however, resistance is frequently observed in malignant cells, operating through a mechanism that remains largely unknown. The present study shows that T-lymphokine-activated killer cell-originated protein kinase (TOPK) is upregulated in NSCLC and excessively activated in TKI-refractory cells. TOPK dictates the responsiveness of lung cancers to the EGFR-targeted TKI gefitinib through the transcription factor AP-1 component c-Jun. TOPK binds directly to and phosphorylates c-Jun, which consequently activates the transcription of AP-1 target genes, including CCND1 and CDC2. TOPK silencing sensitizes EGFR-TKI-resistant lung cancer cells to gefitinib and increases gefitinib efficacy in preclinical lung adenocarcinoma xenograft models. These findings represent a novel mechanism of lung cancer resistance to TKIs and suggest that TOPK may have value both as a predictive biomarker and as a therapeutic target: TOPK-targeted therapy may synergize with EGFR-targeted therapy in lung cancers. PMID:26745678

  20. PGC-1α mediates mitochondrial biogenesis and oxidative phosphorylation in cancer cells to promote metastasis.

    PubMed

    LeBleu, Valerie S; O'Connell, Joyce T; Gonzalez Herrera, Karina N; Wikman, Harriet; Pantel, Klaus; Haigis, Marcia C; de Carvalho, Fernanda Machado; Damascena, Aline; Domingos Chinen, Ludmilla Thome; Rocha, Rafael M; Asara, John M; Kalluri, Raghu

    2014-10-01

    Cancer cells can divert metabolites into anabolic pathways to support their rapid proliferation and to accumulate the cellular building blocks required for tumour growth. However, the specific bioenergetic profile of invasive and metastatic cancer cells is unknown. Here we report that migratory/invasive cancer cells specifically favour mitochondrial respiration and increased ATP production. Invasive cancer cells use the transcription coactivator peroxisome proliferator-activated receptor gamma, coactivator 1 alpha (PPARGC1A, also known as PGC-1α) to enhance oxidative phosphorylation, mitochondrial biogenesis and the oxygen consumption rate. Clinical analysis of human invasive breast cancers revealed a strong correlation between PGC-1α expression in invasive cancer cells and the formation of distant metastases. Silencing of PGC-1α in cancer cells suspended their invasive potential and attenuated metastasis without affecting proliferation, primary tumour growth or the epithelial-to-mesenchymal program. Inherent genetics of cancer cells can determine the transcriptome framework associated with invasion and metastasis, and mitochondrial biogenesis and respiration induced by PGC-1α are also essential for functional motility of cancer cells and metastasis.

  1. Increase in melanin formation and promotion of cytotoxicity in cultured melanoma cells caused by phosphorylated isomers of L-dopa.

    PubMed

    Pawelek, J M; Murray, M

    1986-02-01

    A new class of compounds, termed "dopa phosphates," is described. The compounds contain phosphate ester linkages at positions 3 and/or 4 of the phenylalanine ring. Dopa phosphates are highly soluble compounds which are stable over a wide range of pH values and are not hydrolyzed by boiling in concentrated acid. Synthetic yields of greater than 90% can be obtained using dopa as starting material. Exposure to alkaline phosphatase results in hydrolysis of the phosphate moieties and production of dopa. Dopa phosphates do not inhibit dopa oxidase (tyrosinase, EC 1.14.18.1) activity. Dopa oxidase does not catalyze the conversion of dopa phosphates into melanin unless the dopa phosphates are first treated with alkaline phosphatase. Dopa phosphates, when compared to L-dopa, are stable in the presence of O2 and are not oxidized by serum proteins. In the presence of cultured melanoma cells, dopa phosphates are readily converted into melanin, indicating that the cells are able to produce dopa from dopa phosphates. At high concentrations, dopa phosphates are cytotoxic toward melanoma cells in culture. The cytotoxicity is enhanced at least 3-fold by pretreatment of cells with melanotropin and is prevented by phenylthiourea, an inhibitor of dopa oxidase activity. These results, combined with studies on the uptake of radioactive forms of dopa phosphates (32P and 14C), indicate that phosphorylated isomers of dopa are efficiently taken up by Cloudman melanoma cells and are readily converted by the cells into a melanin precursor, presumably L-dopa.

  2. The expression of HSP27 is associated with poor clinical outcome in intrahepatic cholangiocarcinoma

    PubMed Central

    Romani, Antonello A; Crafa, Pellegrino; Desenzani, Silvia; Graiani, Gallia; Lagrasta, Costanza; Sianesi, Mario; Soliani, Paolo; Borghetti, Angelo F

    2007-01-01

    Background The heat shock proteins (HSPs) 27-kDa (HSP27) and 72-kDa (HSP72), are ubiquitous chaperone molecules inducible in cells exposed to different stress conditions. Increased level of HSPs are reported in several human cancers, and found to be associated with the resistance to some anticancer treatments and poor prognosis. However, there is no study of the relationship between HSPs expression and patient's prognosis in intrahepatic cholangiocarcinoma (IHCCA). In this exploratory retrospective study, we investigated the expressions of HSP27 and HSP72 as potential prognostic factors in IHCCA. Methods Thirty-one paraffin-embedded samples were analyzed by immunohistochemical methods using HSP27 and HSP72 monoclonal antibodies. Proliferation rate was assessed in the same specimens by using monoclonal antibody against phosphorylated histone H3 (pHH3). Fisher's exact test was used to assess the hypothesis of independence between categorical variables in 2 × 2 tables. The ANOVA procedure was used to evaluate the association between ordinal and categorical variables. Estimates of the survival probability were calculated using the Kaplan-Meier method, and the log rank test was employed to test the null hypothesis of equality in overall survival among groups. The hazard ratio associated with HSP27 and HSP72 expression was estimated by Cox hazard-proportional regression. Results The expression of HSP27 was related to mitotic index, tumor greatest dimension, capsular and vascular invasion while the expression of HSP72 was only related to the presence of necrosis and the lymphoid infiltration. Kaplan-Maier analysis suggested that the expression of HSP27 significantly worsened the patients' median overall survival (11 ± 3.18 vs 55 ± 4.1 months, P-value = 0.0003). Moreover HSP27-positive patients exhibited the worst mean survival (7.0 ± 3.2 months) in the absence of concomitant HSP72 expression. Conclusion The expression of HSP27, likely increasing cell proliferation

  3. Transarterial Therapies for the Treatment of Intrahepatic Cholangiocarcinoma

    PubMed Central

    Zechlinski, Joseph J.; Rilling, William S.

    2013-01-01

    Cholangiocarcinoma, whether arising from the intrahepatic or extrahepatic biliary system, is a rare but devastating malignancy. Prognosis is poor, with 5-year overall survival <5% including patients undergoing surgery. Resection is the only curative treatment; however, only ∼30% of patients present at a resectable stage, and intrahepatic recurrence is common even after complete resection. This article discusses the current role of transarterial therapies in the treatment of intrahepatic cholangiocarcinoma. PMID:24436514

  4. Histone phosphorylation

    PubMed Central

    Rossetto, Dorine; Avvakumov, Nikita; Côté, Jacques

    2012-01-01

    Histone posttranslational modifications are key components of diverse processes that modulate chromatin structure. These marks function as signals during various chromatin-based events, and act as platforms for recruitment, assembly or retention of chromatin-associated factors. The best-known function of histone phosphorylation takes place during cellular response to DNA damage, when phosphorylated histone H2A(X) demarcates large chromatin domains around the site of DNA breakage. However, multiple studies have also shown that histone phosphorylation plays crucial roles in chromatin remodeling linked to other nuclear processes. In this review, we summarize the current knowledge of histone phosphorylation and describe the many kinases and phosphatases that regulate it. We discuss the key roles played by this histone mark in DNA repair, transcription and chromatin compaction during cell division and apoptosis. Additionally, we describe the intricate crosstalk that occurs between phosphorylation and other histone modifications and allows for sophisticated control over the chromatin remodeling processes. PMID:22948226

  5. Genetic dissection reveals that Akt is the critical kinase downstream of LRRK2 to phosphorylate and inhibit FOXO1, and promotes neuron survival.

    PubMed

    Chuang, Chia-Lung; Lu, Yu-Ning; Wang, Hung-Cheng; Chang, Hui-Yun

    2014-11-01

    Leucine-rich repeat kinase 2 (LRRK2) is a complex kinase and mutations in LRRK2 are perhaps the most common genetic cause of Parkinson's disease (PD). However, the identification of the normal physiological function of LRRK2 remains elusive. Here, we show that LRRK2 protects neurons against apoptosis induced by the Drosophila genes grim, hid and reaper. Genetic dissection reveals that Akt is the critical downstream kinase of LRRK2 that phosphorylates and inhibits FOXO1, and thereby promotes survival. Like human LRRK2, Drosophila lrrk also promotes neuron survival; lrrk loss-of-function mutant displays reduced cell numbers, which can be rescued by LRRK2 expression. Importantly, LRRK2 G2019S and LRRK2 R1441C mutants impair the ability of LRRK2 to activate Akt, and fail to prevent apoptotic death. Ectopic expression of a constitutive active form of Akt hence is sufficient to rescue this functional deficit. These data establish that LRRK2 can protect neurons from apoptotic insult through a survival pathway in which LRRK2 signals to activate Akt, and then inhibits FOXO1. These results might indicate that a LRRK-Akt therapeutic pathway to promote neuron survival and to prevent neurodegeneration in Parkinson's disease. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  6. Update on the Diagnosis and Treatment of Cholangiocarcinoma.

    PubMed

    Doherty, Bryan; Nambudiri, Vinod E; Palmer, William C

    2017-01-01

    Cholangiocarcinoma is a rare biliary adenocarcinoma associated with poor outcomes. Cholangiocarcinoma is subdivided into extrahepatic and intrahepatic variants. Intrahepatic cholangiocarcinoma is then further differentiated into (1) peripheral mass-forming tumors and (2) central periductal infiltrating tumors. We aimed to review the currently known risk factors, diagnostic tools, and treatment options, as well as highlight the need for further clinical trials and research to improve overall survival rates. Cholangiocarcinoma has seen significant increase in incidence rates over the last several decades. Most patients do not carry the documented risk factors, which include infections and inflammatory conditions, but cholangiocarcinoma typically forms in the setting of cholestasis and chronic inflammation. Management strategies include multispecialty treatments, with consideration of surgical resection, systemic chemotherapy, and targeted radiation therapy. Surgically resectable disease is the only curable treatment option, which may involve liver transplantation in certain selected cases. Referrals to centers of excellence, along with enrollment in novel clinical trials are recommended for patients with unresectable or recurrent disease. This article provides an overview of cholangiocarcinoma and discusses the current diagnosis and treatment options. While incidence is increasing and more risk factors are being discovered, much more work remains to improve outcomes of this ominous disease.

  7. Role of Endoscopic Ultrasonography in the Evaluation of Extrahepatic Cholangiocarcinoma

    PubMed Central

    Strongin, Anna; Singh, Harkirat; Eloubeidi, Mohamad A.; Siddiqui, Ali A.

    2013-01-01

    Cholangiocarcinoma is a malignancy that arises from biliary epithelium and is associated with a poor prognosis. Accurate preopera-tive diagnosis and staging of cholangiocarcinoma continues to remain difficult. Endoscopic retrograde cholangiopancreatography (ERCP) is the most commonly performed procedure for cholangiocarcinoma and can provide a tissue diagnosis through brush cytology of the bile duct. However, the sensitivity of biliary brush cytology to diagnose cholangiocarcinoma may be as low as 30%. Endoscopic ultrasound (EUS) is a diagnostic modality which may overcome the limitations of other imaging and biopsy techniques in this setting. EUS can complement the role of ERCP and provide a tissue diagnosis through fine needle aspiration (FNA) and staging through ultrasound imaging. There is currently a paucity of data about the exact role of EUS for the diagnosis of cholan-giocarcinoma in patients with indeterminate extrahepatic biliary strictures. Although multiple studies have shown that EUS is more accurate than ERCP and radiologic imaging for identifying a biliary mass and diagnosing cholangiocarcinoma, the sensitivities are variable. More importantly, the incidence of false negative results is not negligible, though the specificity is close to 100%. There is also controversy regarding the role of EUS-FNA, since even though this may increase diagnosis, it can also lead to tumor seeding. PMID:24949368

  8. H3 Histamine Receptor–Mediated Activation of Protein Kinase Cα Inhibits the Growth of Cholangiocarcinoma In vitro and In vivo

    PubMed Central

    Francis, Heather; Onori, Paolo; Gaudio, Eugenio; Franchitto, Antonio; DeMorrow, Sharon; Venter, Julie; Kopriva, Shelley; Carpino, Guido; Mancinelli, Romina; White, Mellanie; Meng, Fanyin; Vetuschi, Antonella; Sferra, Roberta; Alpini, Gianfranco

    2009-01-01

    Histamine regulates functions via four receptors (HRH1, HRH2, HRH3, and HRH4). The d-myo-inositol 1,4,5-trisphosphate (IP3)/Ca2+/protein kinase C (PKC)/mitogen-activated protein kinase pathway regulates cholangiocarcinoma growth. We evaluated the role of HRH3 in the regulation of cholangiocarcinoma growth. Expression of HRH3 in intrahepatic and extrahepatic cell lines, normal cholangiocytes, and human tissue arrays was measured. In Mz-ChA-1 cells stimulated with (R)-(α)-(−)-methylhistamine dihydrobromide (RAMH), we measured (a) cell growth, (b) IP3 and cyclic AMP levels, and (c) phosphorylation of PKC and mitogen-activated protein kinase isoforms. Localization of PKCα was visualized by immunofluorescence in cell smears and immunoblotting for PKCα in cytosol and membrane fractions. Following knockdown of PKCα, Mz-ChA-1 cells were stimulated with RAMH before evaluating cell growth and extracellular signal–regulated kinase (ERK)-1/2 phosphorylation. In vivo experiments were done in BALB/c nude mice. Mice were treated with saline or RAMH for 44 days and tumor volume was measured. Tumors were excised and evaluated for proliferation, apoptosis, and expression of PKCα, vascular endothelial growth factor (VEGF)-A, VEGF-C, VEGF receptor 2, and VEGF receptor 3. HRH3 expression was found in all cells. RAMH inhibited the growth of cholangiocarcinoma cells. RAMH increased IP3 levels and PKCα phosphorylation and decreased ERK1/2 phosphorylation. RAMH induced a shift in the localization of PKCα expression from the cytosolic domain into the membrane region of Mz-ChA-1 cells. Silencing of PKCα prevented RAMH inhibition of Mz-ChA-1 cell growth and ablated RAMH effects on ERK1/2 phosphorylation. In vivo, RAMH decreased tumor growth and expression of VEGF and its receptors; PKCα expression was increased. RAMH inhibits cholangiocarcinoma growth by PKCα-dependent ERK1/2 dephosphorylation. Modulation of PKCα by histamine receptors may be important in regulating

  9. Tumor reactive stroma in cholangiocarcinoma: The fuel behind cancer aggressiveness

    PubMed Central

    Brivio, Simone; Cadamuro, Massimiliano; Strazzabosco, Mario; Fabris, Luca

    2017-01-01

    Cholangiocarcinoma (CCA) is a highly aggressive epithelial malignancy still carrying a dismal prognosis, owing to early lymph node metastatic dissemination and striking resistance to conventional chemotherapy. Although mechanisms underpinning CCA progression are still a conundrum, it is now increasingly recognized that the desmoplastic microenvironment developing in conjunction with biliary carcinogenesis, recently renamed tumor reactive stroma (TRS), behaves as a paramount tumor-promoting driver. Indeed, once being recruited, activated and dangerously co-opted by neoplastic cells, the cellular components of the TRS (myofibroblasts, macrophages, endothelial cells and mesenchymal stem cells) continuously rekindle malignancy by secreting a huge variety of soluble factors (cyto/chemokines, growth factors, morphogens and proteinases). Furthermore, these factors are long-term stored within an abnormally remodeled extracellular matrix (ECM), which in turn can deleteriously mold cancer cell behavior. In this review, we will highlight evidence for the active role played by reactive stromal cells (as well as by the TRS-associated ECM) in CCA progression, including an overview of the most relevant TRS-derived signals possibly fueling CCA cell aggressiveness. Hopefully, a deeper knowledge of the paracrine communications reciprocally exchanged between cancer and stromal cells will steer the development of innovative, combinatorial therapies, which can finally hinder the progression of CCA, as well as of other cancer types with abundant TRS, such as pancreatic and breast carcinomas. PMID:28396716

  10. Notch3 drives development and progression of cholangiocarcinoma.

    PubMed

    Guest, Rachel V; Boulter, Luke; Dwyer, Benjamin J; Kendall, Timothy J; Man, Tak-Yung; Minnis-Lyons, Sarah E; Lu, Wei-Yu; Robson, Andrew J; Gonzalez, Sofia Ferreira; Raven, Alexander; Wojtacha, Davina; Morton, Jennifer P; Komuta, Mina; Roskams, Tania; Wigmore, Stephen J; Sansom, Owen J; Forbes, Stuart J

    2016-10-25

    The prognosis of cholangiocarcinoma (CC) is dismal. Notch has been identified as a potential driver; forced exogenous overexpression of Notch1 in hepatocytes results in the formation of biliary tumors. In human disease, however, it is unknown which components of the endogenously signaling pathway are required for tumorigenesis, how these orchestrate cancer, and how they can be targeted for therapy. Here we characterize Notch in human-resected CC, a toxin-driven model in rats, and a transgenic mouse model in which p53 deletion is targeted to biliary epithelia and CC induced using the hepatocarcinogen thioacetamide. We find that across species, the atypical receptor NOTCH3 is differentially overexpressed; it is progressively up-regulated with disease development and promotes tumor cell survival via activation of PI3k-Akt. We use genetic KO studies to show that tumor growth significantly attenuates after Notch3 deletion and demonstrate signaling occurs via a noncanonical pathway independent of the mediator of classical Notch, Recombinant Signal Binding Protein for Immunoglobulin Kappa J Region (RBPJ). These data present an opportunity in this aggressive cancer to selectively target Notch, bypassing toxicities known to be RBPJ dependent.

  11. Notch3 drives development and progression of cholangiocarcinoma

    PubMed Central

    Guest, Rachel V.; Dwyer, Benjamin J.; Kendall, Timothy J.; Man, Tak-Yung; Minnis-Lyons, Sarah E.; Lu, Wei-Yu; Robson, Andrew J.; Gonzalez, Sofia Ferreira; Raven, Alexander; Wojtacha, Davina; Morton, Jennifer P.; Komuta, Mina; Roskams, Tania; Wigmore, Stephen J.; Sansom, Owen J.; Forbes, Stuart J.

    2016-01-01

    The prognosis of cholangiocarcinoma (CC) is dismal. Notch has been identified as a potential driver; forced exogenous overexpression of Notch1 in hepatocytes results in the formation of biliary tumors. In human disease, however, it is unknown which components of the endogenously signaling pathway are required for tumorigenesis, how these orchestrate cancer, and how they can be targeted for therapy. Here we characterize Notch in human-resected CC, a toxin-driven model in rats, and a transgenic mouse model in which p53 deletion is targeted to biliary epithelia and CC induced using the hepatocarcinogen thioacetamide. We find that across species, the atypical receptor NOTCH3 is differentially overexpressed; it is progressively up-regulated with disease development and promotes tumor cell survival via activation of PI3k-Akt. We use genetic KO studies to show that tumor growth significantly attenuates after Notch3 deletion and demonstrate signaling occurs via a noncanonical pathway independent of the mediator of classical Notch, Recombinant Signal Binding Protein for Immunoglobulin Kappa J Region (RBPJ). These data present an opportunity in this aggressive cancer to selectively target Notch, bypassing toxicities known to be RBPJ dependent. PMID:27791012

  12. Cholangiocarcinoma: Current Knowledge and New Developments

    PubMed Central

    Blechacz, Boris

    2017-01-01

    Cholangiocarcinoma (CCA) is the second most common primary malignancy. Although it is more common in Asia, its incidence in Europe and North America has significantly increased in recent decades. The prognosis of CCA is dismal. Surgery is the only potentially curative treatment, but the majority of patients present with advanced stage disease, and recurrence after resection is common. Over the last two decades, our understanding of the molecular biology of this malignancy has increased tremendously, diagnostic techniques have evolved, and novel therapeutic approaches have been established. This review discusses the changing epidemiologic trends and provides an overview of newly identified etiologic risk factors for CCA. Furthermore, the molecular pathogenesis is discussed as well as the influence of etiology and biliary location on the mutational landscape of CCA. This review provides an overview of the diagnostic evaluation of CCA and its staging systems. Finally, new therapeutic options are critically reviewed, and future therapeutic strategies discussed. PMID:27928095

  13. Cholangiocarcinomas can originate from hepatocytes in mice

    PubMed Central

    Fan, Biao; Malato, Yann; Calvisi, Diego F.; Naqvi, Syed; Razumilava, Nataliya; Ribback, Silvia; Gores, Gregory J.; Dombrowski, Frank; Evert, Matthias; Chen, Xin; Willenbring, Holger

    2012-01-01

    Intrahepatic cholangiocarcinomas (ICCs) are primary liver tumors with a poor prognosis. The development of effective therapies has been hampered by a limited understanding of the biology of ICCs. Although ICCs exhibit heterogeneity in location, histology, and marker expression, they are currently thought to derive invariably from the cells lining the bile ducts, biliary epithelial cells (BECs), or liver progenitor cells (LPCs). Despite lack of experimental evidence establishing BECs or LPCs as the origin of ICCs, other liver cell types have not been considered. Here we show that ICCs can originate from fully differentiated hepatocytes. Using a mouse model of hepatocyte fate tracing, we found that activated NOTCH and AKT signaling cooperate to convert normal hepatocytes into biliary cells that act as precursors of rapidly progressing, lethal ICCs. Our findings suggest a previously overlooked mechanism of human ICC formation that may be targetable for anti-ICC therapy. PMID:22797301

  14. Cholangiocarcinoma: Molecular Pathways and Therapeutic Opportunities

    PubMed Central

    Rizvi, Sumera; Borad, Mitesh J.; Patel, Tushar; Gores, Gregory J.

    2015-01-01

    Cholangiocarcinoma (CCA) is an aggressive biliary tract malignancy with limited treatment options and low survival rates. Currently, there are no curative medical therapies for CCA. Recent advances have enhanced our understanding of the genetic basis of this disease, and elucidated therapeutically relevant targets. Therapeutic efforts in development are directed at several key pathways due to genetic aberrations including receptor tyrosine kinase pathways, mutant IDH enzymes, the PI3K-AKT-mTOR pathway, and chromatin remodeling networks. A highly desmoplastic, hypovascular stroma is characteristic of CCAs and recent work has highlighted the importance of targeting this pathway via stromal myofibroblast depletion. Future efforts should concentrate on combination therapies with action against the cancer cell and the surrounding tumor stroma. As the mutational landscape of CCA is being illuminated, molecular profiling of patient tumors will enable identification of specific mutations and the opportunity to offer directed, personalized treatment options. PMID:25369307

  15. Classification, Diagnosis, and Management of Cholangiocarcinoma

    PubMed Central

    Razumilava, Nataliya; Gores, Gregory J.

    2013-01-01

    Cholangiocarcinomas (CCAs) are tumors that develop along the biliary tract. Depending on their site of origin, they have different features and require specific treatments. Classification of CCAs into intrahepatic, perihilar, and distal subgroups has helped standardize the registration, treatment, and study of this lethal malignancy. Physicians should remain aware that cirrhosis and viral hepatitis B and C are predisposing conditions for intrahepatic CCA. Treatment options under development include locoregional therapies and a chemotherapy regimen of gemcitabine and cisplatin. It is a challenge to diagnose perihilar CCA, but an advanced cytologic technique of fluorescence in situ hybridization for polysomy can aid in diagnosis. It is important to increase our understanding of the use of biliary stents and liver transplantation in the management of perihilar CCA, as well as to distinguish distal CCAs from pancreatic cancer, because of different outcomes from surgery. We review advances in the classification, diagnosis, and staging of CCA, along with treatment options. PMID:22982100

  16. Cholangiocarcinoma: Current Knowledge and New Developments.

    PubMed

    Blechacz, Boris

    2017-01-15

    Cholangiocarcinoma (CCA) is the second most common primary malignancy. Although it is more common in Asia, its incidence in Europe and North America has significantly increased in recent decades. The prognosis of CCA is dismal. Surgery is the only potentially curative treatment, but the majority of patients present with advanced stage disease, and recurrence after resection is common. Over the last two decades, our understanding of the molecular biology of this malignancy has increased tremendously, diagnostic techniques have evolved, and novel therapeutic approaches have been established. This review discusses the changing epidemiologic trends and provides an overview of newly identified etiologic risk factors for CCA. Furthermore, the molecular pathogenesis is discussed as well as the influence of etiology and biliary location on the mutational landscape of CCA. This review provides an overview of the diagnostic evaluation of CCA and its staging systems. Finally, new therapeutic options are critically reviewed, and future therapeutic strategies discussed.

  17. The significance of genetics for cholangiocarcinoma development

    PubMed Central

    Maroni, Luca; Pierantonelli, Irene; Banales, Jesus M.; Benedetti, Antonio

    2013-01-01

    Cholangiocarcinoma (CCA) is a rare malignancy of the liver, arising from bile ducts. The incidence is increasing worldwide, but the prognosis has remained dismal and virtually unchanged in the past 30 years. Although several risk factors have been associated with the development of this cancer, none of them are normally identified in most patients. Diagnosis in advanced stages of the disease and limited therapeutic options contribute to poor survival rates. The recent analysis of genetic and epigenetic alterations occurring in CCA has shed new light in the understanding of the molecular mechanisms leading to the malignant transformation of biliary cells. Further studies in this direction may foster new diagnostic, prognostic and therapeutic approaches. This review provides a global overview of recent advances in CCA and describes the most important genetic mutations and epigenetic alterations so far reported in CCA. PMID:25332972

  18. The significance of genetics for cholangiocarcinoma development.

    PubMed

    Maroni, Luca; Pierantonelli, Irene; Banales, Jesus M; Benedetti, Antonio; Marzioni, Marco

    2013-10-01

    Cholangiocarcinoma (CCA) is a rare malignancy of the liver, arising from bile ducts. The incidence is increasing worldwide, but the prognosis has remained dismal and virtually unchanged in the past 30 years. Although several risk factors have been associated with the development of this cancer, none of them are normally identified in most patients. Diagnosis in advanced stages of the disease and limited therapeutic options contribute to poor survival rates. The recent analysis of genetic and epigenetic alterations occurring in CCA has shed new light in the understanding of the molecular mechanisms leading to the malignant transformation of biliary cells. Further studies in this direction may foster new diagnostic, prognostic and therapeutic approaches. This review provides a global overview of recent advances in CCA and describes the most important genetic mutations and epigenetic alterations so far reported in CCA.

  19. Current Status on Cholangiocarcinoma and Gallbladder Cancer

    PubMed Central

    Ebata, Tomoki; Ercolani, Giorgio; Alvaro, Domenico; Ribero, Dario; Di Tommaso, Luca; Valle, Juan W.

    2016-01-01

    Background Cholangiocarcinomas (CC) as well as gallbladder cancers are relatively rare and intractable diseases. Clinical, pathological, and epidemiological studies on these tumors have been under investigation. The current status and/or topics on biliary tract cancers have been reported in the East West Association of Liver Tumor (EWALT), held in Milano, Italy in 2015. Summary All the authors, herein, specifcally reported the current status and leading-edge findings on biliary tract cancers as the following sequence: epidemiology of CC, surgical therapy for intrahepatic CC, surgical therapy for perihilar CC, surgical therapy for gallblad der cancer, chemotherapy for biliary tract cancers, and new histological features in CC. Key Message The present review article will update the knowledge on biliary tract cancers, en hancing the quality of daily clinical practice. However, many features about these cancers remain unknown; further studies are required to establish disease-specific optimal treatment strategies. PMID:27995089

  20. The Unfolded Protein Response and the Phosphorylations of Activating Transcription Factor 2 in the trans-Activation of il23a Promoter Produced by β-Glucans*

    PubMed Central

    Rodríguez, Mario; Domingo, Esther; Alonso, Sara; Frade, Javier García; Eiros, José; Crespo, Mariano Sánchez; Fernández, Nieves

    2014-01-01

    Current views on the control of IL-23 production focus on the regulation of il23a, the gene encoding IL-23 p19, by NF-κB in combination with other transcription factors. C/EBP homologous protein (CHOP), X2-Box-binding protein 1 (XBP1), activator protein 1 (AP1), SMAD, CCAAT/enhancer-binding protein (C/EBPβ), and cAMP-response element-binding protein (CREB) have been involved in response to LPS, but no data are available regarding the mechanism triggered by the fungal mimic and β-glucan-containing stimulus zymosan, which produces IL-23 and to a low extent the related cytokine IL-12 p70. Zymosan induced the mobilization of CHOP from the nuclear fractions to phagocytic vesicles. Hypha-forming Candida also induced the nuclear disappearance of CHOP. Assay of transcription factor binding to the il23a promoter showed an increase of Thr(P)-71–Thr(P)-69-activating transcription factor 2 (ATF2) binding in response to zymosan. PKC and PKA/mitogen- and stress-activated kinase inhibitors down-regulated Thr(P)-71–ATF2 binding to the il23a promoter and il23a mRNA expression. Consistent with the current concept of complementary phosphorylations on N-terminal Thr-71 and Thr-69 of ATF2 by ERK and p38 MAPK, MEK, and p38 MAPK inhibitors blunted Thr(P)-69–ATF2 binding. Knockdown of atf2 mRNA with siRNA correlated with inhibition of il23a mRNA, but it did not affect the expression of il12/23b and il10 mRNA. These data indicate the following: (i) zymosan decreases nuclear proapoptotic CHOP, most likely by promoting its accumulation in phagocytic vesicles; (ii) zymosan-induced il23a mRNA expression is best explained through coordinated κB- and ATF2-dependent transcription; and (iii) il23a expression relies on complementary phosphorylation of ATF2 on Thr-69 and Thr-71 dependent on PKC and MAPK activities. PMID:24982422

  1. Phosphorylation of Rab-coupling protein by LMTK3 controls Rab14-dependent EphA2 trafficking to promote cell:cell repulsion.

    PubMed

    Gundry, Christine; Marco, Sergi; Rainero, Elena; Miller, Bryan; Dornier, Emmanuel; Mitchell, Louise; Caswell, Patrick T; Campbell, Andrew D; Hogeweg, Anna; Sansom, Owen J; Morton, Jennifer P; Norman, Jim C

    2017-03-15

    The Rab GTPase effector, Rab-coupling protein (RCP) is known to promote invasive behaviour in vitro by controlling integrin and receptor tyrosine kinase (RTK) trafficking, but how RCP influences metastasis in vivo is unclear. Here we identify an RTK of the Eph family, EphA2, to be a cargo of an RCP-regulated endocytic pathway which controls cell:cell repulsion and metastasis in vivo. Phosphorylation of RCP at Ser(435) by Lemur tyrosine kinase-3 (LMTK3) and of EphA2 at Ser(897) by Akt are both necessary to promote Rab14-dependent (and Rab11-independent) trafficking of EphA2 which generates cell:cell repulsion events that drive tumour cells apart. Genetic disruption of RCP or EphA2 opposes cell:cell repulsion and metastasis in an autochthonous mouse model of pancreatic adenocarcinoma-whereas conditional knockout of another RCP cargo, α5 integrin, does not suppress pancreatic cancer metastasis-indicating a role for RCP-dependent trafficking of an Eph receptor to drive tumour dissemination in vivo.

  2. Phosphorylation of Rab-coupling protein by LMTK3 controls Rab14-dependent EphA2 trafficking to promote cell:cell repulsion

    PubMed Central

    Gundry, Christine; Marco, Sergi; Rainero, Elena; Miller, Bryan; Dornier, Emmanuel; Mitchell, Louise; Caswell, Patrick T.; Campbell, Andrew D.; Hogeweg, Anna; Sansom, Owen J.; Morton, Jennifer P.; Norman, Jim C.

    2017-01-01

    The Rab GTPase effector, Rab-coupling protein (RCP) is known to promote invasive behaviour in vitro by controlling integrin and receptor tyrosine kinase (RTK) trafficking, but how RCP influences metastasis in vivo is unclear. Here we identify an RTK of the Eph family, EphA2, to be a cargo of an RCP-regulated endocytic pathway which controls cell:cell repulsion and metastasis in vivo. Phosphorylation of RCP at Ser435 by Lemur tyrosine kinase-3 (LMTK3) and of EphA2 at Ser897 by Akt are both necessary to promote Rab14-dependent (and Rab11-independent) trafficking of EphA2 which generates cell:cell repulsion events that drive tumour cells apart. Genetic disruption of RCP or EphA2 opposes cell:cell repulsion and metastasis in an autochthonous mouse model of pancreatic adenocarcinoma—whereas conditional knockout of another RCP cargo, α5 integrin, does not suppress pancreatic cancer metastasis—indicating a role for RCP-dependent trafficking of an Eph receptor to drive tumour dissemination in vivo. PMID:28294115

  3. Ciliary Neurotrophic Factor Promotes the Migration of Corneal Epithelial Stem/progenitor Cells by Up-regulation of MMPs through the Phosphorylation of Akt

    PubMed Central

    Chen, Jialin; Chen, Peng; Backman, Ludvig J.; Zhou, Qingjun; Danielson, Patrik

    2016-01-01

    The migration of limbal epithelial stem cells is important for the homeostasis and regeneration of corneal epithelium. Ciliary neurotrophic factor (CNTF) has been found to promote corneal epithelial wound healing by activating corneal epithelial stem/progenitor cells. However, the possible effect of CNTF on the migration of corneal epithelial stem/progenitor cells is not clear. This study found the expression of CNTF in mouse corneal epithelial stem/progenitor cells (TKE2) to be up-regulated after injury, on both gene and protein level. CNTF promoted migration of TKE2 in a dose-dependent manner and the peak was seen at 10 ng/ml. The phosphorylation level of Akt (p-Akt), and the expression of MMP3 and MMP14, were up-regulated after CNTF treatment both in vitro and in vivo. Akt and MMP3 inhibitor treatment delayed the migration effect by CNTF. Finally, a decreased expression of MMP3 and MMP14 was observed when Akt inhibitor was applied both in vitro and in vivo. This study provides new insights into the role of CNTF on the migration of corneal epithelial stem/progenitor cells and its inherent mechanism of Up-regulation of matrix metalloproteinases through the Akt signalling pathway. PMID:27174608

  4. Nemo phosphorylates Even-skipped and promotes Eve-mediated repression of odd-skipped in even parasegments during Drosophila embryogenesis.

    PubMed

    Braid, Lorena R; Lee, Wendy; Uetrecht, Andrea C; Swarup, Sharan; Papaianni, Gina; Heiler, Amanda; Verheyen, Esther M

    2010-07-01

    Drosophila nemo (nmo) and other Nemo-like kinase family members (Nlks) are well-established key regulators of numerous conserved signaling pathways, such as Wg and BMP. nmo mutants display pleiotropic defects at different developmental stages, including the embryo. In this study we describe a detailed characterization of embryonic cuticle patterning defects associated with maternal loss of nmo. nmo mutant embryos consistently show segmentation defects, most frequently fusions of pairs of denticle belts in alternating segments. These phenotypes are reminiscent of those associated with defects in pair-rule patterning. Genetic interaction studies demonstrate that Nmo promotes Even-skipped (Eve) activity and is required to promote the expression of the Eve target, engrailed (en), in even numbered parasegments. We find that Nmo regulates a subset of Eve activities by stimulating Eve-mediated suppression of the odd-skipped (odd) repressor. Furthermore, we isolate Nmo in a protein complex with Eve and show that Nmo phosphorylates Eve in in vitro kinase assays. These studies reveal a novel role for the Nmo kinase in embryonic pattern formation through its regulation of the homeodomain-containing transcription factor Eve. Copyright 2010 Elsevier Inc. All rights reserved.

  5. Ryanodine Receptor Phosphorylation by CaMKII Promotes Spontaneous Ca2+ Release Events in a Rodent Model of Early Stage Diabetes: the Arrhythmogenic Substrate

    PubMed Central

    Sommese, Leandro; Valverde, Carlos A; Blanco, Paula; Castro, María Cecilia; Rueda, Omar Velez; Kaetzel, Marcia; Dedman, John; Anderson, Mark E.; Mattiazzi, Alicia; Palomeque, Julieta

    2016-01-01

    Background Heart failure and arrhythmias occur more frequently in patients with type 2 diabetes (T2DM) than in the general population. T2DM is preceded by a prediabetic condition marked by elevated reactive oxygen species (ROS) and subclinical cardiovascular defects. Although multifunctional Ca2+ calmodulin-dependent protein kinase II (CaMKII) is ROS-activated and CaMKII hyperactivity promotes cardiac diseases, a link between prediabetes and CaMKII in the heart is unprecedented. Objectives to prove the hypothesis that increased ROS and CaMKII activity contribute to heart failure and arrhythmogenic mechanisms in early stage diabetes. Methods-Results Echocardiography, electrocardiography, biochemical and intracellular Ca2+ (Ca2+i) determinations were performed in fructose-rich diet -induced impaired glucose tolerance, a prediabetes model, in rodents. Fructose-rich diet rats showed decreased contractility and hypertrophy associated with increased CaMKII activity, ROS production, oxidized CaMKII and enhanced CaMKII-dependent ryanodine receptor (RyR2) phosphorylation compared to rats fed with control diet. Isolated cardiomyocytes from fructose-rich diet showed increased spontaneous Ca2+i release events associated with spontaneous contractions, which were prevented by KN-93, a CaMKII inhibitor, or addition of Tempol, a ROS scavenger, to the diet. Moreover, fructose-rich diet myocytes showed increased diastolic Ca2+ during the burst of spontaneous Ca2+i release events. Micetreated with Tempol or with sarcoplasmic reticulum-targeted CaMKII-inhibition by transgenic expression of the CaMKII inhibitory peptide AIP, were protected from fructose-rich diet-induced spontaneous Ca2+i release events, spontaneous contractions and arrhythmogenes is in vivo, despite ROS increases. Conclusions RyR2 phosphorylation by ROS-activated CaMKII, contributes to impaired glucose tolerance-induced arrhythmogenic mechanisms, suggesting that CaMKII inhibition could prevent prediabetic

  6. Ryanodine receptor phosphorylation by CaMKII promotes spontaneous Ca(2+) release events in a rodent model of early stage diabetes: The arrhythmogenic substrate.

    PubMed

    Sommese, Leandro; Valverde, Carlos A; Blanco, Paula; Castro, María Cecilia; Rueda, Omar Velez; Kaetzel, Marcia; Dedman, John; Anderson, Mark E; Mattiazzi, Alicia; Palomeque, Julieta

    2016-01-01

    Heart failure and arrhythmias occur more frequently in patients with type 2 diabetes (T2DM) than in the general population. T2DM is preceded by a prediabetic condition marked by elevated reactive oxygen species (ROS) and subclinical cardiovascular defects. Although multifunctional Ca2+ calmodulin-dependent protein kinase II (CaMKII) is ROS-activated and CaMKII hyperactivity promotes cardiac diseases, a link between prediabetes and CaMKII in the heart is unprecedented. To prove the hypothesis that increased ROS and CaMKII activity contribute to heart failure and arrhythmogenic mechanisms in early stage diabetes. Echocardiography, electrocardiography, biochemical and intracellular Ca2+ (Ca2+i) determinations were performed in fructose-rich diet-induced impaired glucose tolerance, a prediabetes model, in rodents. Fructose-rich diet rats showed decreased contractility and hypertrophy associated with increased CaMKII activity, ROS production, oxidized CaMKII and enhanced CaMKII-dependent ryanodine receptor (RyR2) phosphorylation compared to rats fed with control diet. Isolated cardiomyocytes from fructose-rich diet showed increased spontaneous Ca2+i release events associated with spontaneous contractions, which were prevented by KN-93, a CaMKII inhibitor, or addition of Tempol, a ROS scavenger, to the diet. Moreover, fructose-rich diet myocytes showed increased diastolic Ca2+ during the burst of spontaneous Ca2+i release events. Mice treated with Tempol or with sarcoplasmic reticulum-targeted CaMKII-inhibition by transgenic expression of the CaMKII inhibitory peptide AIP, were protected from fructose-rich diet-induced spontaneous Ca2+i release events, spontaneous contractions and arrhythmogenesis in vivo, despite ROS increases. RyR2 phosphorylation by ROS-activated CaMKII, contributes to impaired glucose tolerance-induced arrhythmogenic mechanisms, suggesting that CaMKII inhibition could prevent prediabetic cardiovascular complications and/or evolution. Copyright

  7. Oxidative stress-mediated NFκB phosphorylation upregulates p62/SQSTM1 and promotes retinal pigmented epithelial cell survival through increased autophagy.

    PubMed

    Song, Chunjuan; Mitter, Sayak K; Qi, Xiaoping; Beli, Eleni; Rao, Haripriya V; Ding, Jindong; Ip, Colin S; Gu, Hongmei; Akin, Debra; Dunn, William A; Bowes Rickman, Catherine; Lewin, Alfred S; Grant, Maria B; Boulton, Michael E

    2017-01-01

    p62 is a scaffolding adaptor implicated in the clearance of protein aggregates by autophagy. Reactive oxygen species (ROS) can either stimulate or inhibit NFκB-mediated gene expression influencing cellular fate. We studied the effect of hydrogen peroxide (H2O2)-mediated oxidative stress and NFκB signaling on p62 expression in the retinal pigment epithelium (RPE) and investigated its role in regulation of autophagy and RPE survival against oxidative damage. Cultured human RPE cell line ARPE-19 and primary human adult and fetal RPE cells were exposed to H2O2-induced oxidative stress. The human apolipoprotein E4 targeted-replacement (APOE4) mouse model of AMD was used to study expression of p62 and other autophagy proteins in the retina. p62, NFκB p65 (total, phosphorylated, nuclear and cytoplasmic) and ATG10 expression was assessed by mRNA and protein analyses. Cellular ROS and mitochondrial superoxide were measured by CM-H2DCFDA and MitoSOX staining respectively. Mitochondrial viability was determined using MTT activity. qPCR-array system was used to investigate autophagic genes affected by p62. Nuclear and cytoplasmic levels of NFκB p65 were evaluated after cellular fractionation by Western blotting. We report that p62 is up-regulated in RPE cells under H2O2-induced oxidative stress and promotes autophagic activity. Depletion of endogenous p62 reduces autophagy by downregulation of ATG10 rendering RPE more susceptible to oxidative damage. NFκB p65 phosphorylation at Ser-536 was found to be critical for p62 upregulation in response to oxidative stress. Proteasome inhibition by H2O2 causes p62-NFκB signaling as antioxidant pre-treatment reversed p62 expression and p65 phosphorylation when RPE was challenged by H2O2 but not when by Lactacystin. p62 protein but not RNA levels are elevated in APOE4-HFC AMD mouse model, suggesting reduction of autophagic flux in disease conditions. Our findings suggest that p62 is necessary for RPE cytoprotection under oxidative

  8. Oxidative stress-mediated NFκB phosphorylation upregulates p62/SQSTM1 and promotes retinal pigmented epithelial cell survival through increased autophagy

    PubMed Central

    Qi, Xiaoping; Beli, Eleni; Rao, Haripriya V.; Ding, Jindong; Ip, Colin S.; Gu, Hongmei; Akin, Debra; Dunn, William A.; Bowes Rickman, Catherine; Lewin, Alfred S.; Grant, Maria B.; Boulton, Michael E.

    2017-01-01

    p62 is a scaffolding adaptor implicated in the clearance of protein aggregates by autophagy. Reactive oxygen species (ROS) can either stimulate or inhibit NFκB-mediated gene expression influencing cellular fate. We studied the effect of hydrogen peroxide (H2O2)-mediated oxidative stress and NFκB signaling on p62 expression in the retinal pigment epithelium (RPE) and investigated its role in regulation of autophagy and RPE survival against oxidative damage. Cultured human RPE cell line ARPE-19 and primary human adult and fetal RPE cells were exposed to H2O2-induced oxidative stress. The human apolipoprotein E4 targeted-replacement (APOE4) mouse model of AMD was used to study expression of p62 and other autophagy proteins in the retina. p62, NFκB p65 (total, phosphorylated, nuclear and cytoplasmic) and ATG10 expression was assessed by mRNA and protein analyses. Cellular ROS and mitochondrial superoxide were measured by CM-H2DCFDA and MitoSOX staining respectively. Mitochondrial viability was determined using MTT activity. qPCR-array system was used to investigate autophagic genes affected by p62. Nuclear and cytoplasmic levels of NFκB p65 were evaluated after cellular fractionation by Western blotting. We report that p62 is up-regulated in RPE cells under H2O2-induced oxidative stress and promotes autophagic activity. Depletion of endogenous p62 reduces autophagy by downregulation of ATG10 rendering RPE more susceptible to oxidative damage. NFκB p65 phosphorylation at Ser-536 was found to be critical for p62 upregulation in response to oxidative stress. Proteasome inhibition by H2O2 causes p62-NFκB signaling as antioxidant pre-treatment reversed p62 expression and p65 phosphorylation when RPE was challenged by H2O2 but not when by Lactacystin. p62 protein but not RNA levels are elevated in APOE4-HFC AMD mouse model, suggesting reduction of autophagic flux in disease conditions. Our findings suggest that p62 is necessary for RPE cytoprotection under oxidative

  9. HIV-1 Tat interaction with RNA polymerase II C-terminal domain (CTD) and a dynamic association with CDK2 induce CTD phosphorylation and transcription from HIV-1 promoter.

    PubMed

    Deng, Longwen; Ammosova, Tatyana; Pumfery, Anne; Kashanchi, Fatah; Nekhai, Sergei

    2002-09-13

    Human immunodeficiency virus, type 1 (HIV-1), Tat protein activates viral gene expression through promoting transcriptional elongation by RNA polymerase II (RNAPII). In this process Tat enhances phosphorylation of the C-terminal domain (CTD) of RNAPII by activating cell cycle-dependent kinases (CDKs) associated with general transcription factors of the promoter complex, specifically CDK7 and CDK9. We reported a Tat-associated T-cell-derived kinase, which contained CDK2. Here, we provide further evidence that CDK2 is involved in Tat-mediated CTD phosphorylation and in HIV-1 transcription in vitro. Tat-mediated CTD phosphorylation by CDK2 required cysteine 22 in the activation domain of Tat and amino acids 42-72 of Tat. CDK2 phosphorylated Tat itself, apparently by forming dynamic contacts with amino acids 15-24 and 36-49 of Tat. Also, amino acids 24-36 and 45-72 of Tat interacted with CTD. CDK2 associated with RNAPII and was found in elongation complexes assembled on HIV-1 long-terminal repeat template. Recombinant CDK2/cyclin E stimulated Tat-dependent HIV-1 transcription in reconstituted transcription assay. Immunodepletion of CDK2/cyclin E in HeLa nuclear extract blocked Tat-dependent transcription. We suggest that CDK2 is part of a transcription complex that is required for Tat-dependent transcription and that interaction of Tat with CTD and a dynamic association of Tat with CDK2/cyclin E stimulated CTD phosphorylation by CDK2.

  10. Periostin in intrahepatic cholangiocarcinoma: pathobiological insights and clinical implications.

    PubMed

    Sirica, Alphonse E; Almenara, Jorge A; Li, Chao

    2014-12-01

    Periostin is a modular glycoprotein frequently observed to be a major constituent of the extracellular milieu of mass-forming intrahepatic cholangiocarcinoma and other desmoplastic malignant tumors. In intrahepatic cholangiocarcinoma, as well as in desmoplastic pancreatic ductal adenocarcinoma, periostin is overexpressed and hypersecreted in large part, if not exclusively, by cancer-associated fibroblasts within the tumor stroma. Through its interaction with specific components of the extracellular tumor matrix, particularly collagen type I and tenascin-C, and with cell surface receptors, notably integrins leading to activation of the Akt and FAK signaling pathways, this TGF-β family-inducible matricellular protein appears to be functioning as a key extracellular matrix molecule regulating such critically important and diverse malignant tumor behaviors as tumor fibrogenesis and desmoplasia, invasive malignant cell growth, chemoresistance, and metastatic colonization. This review will discuss current evidence and basic molecular mechanisms implicating periostin as a mediator of intrahepatic cholangiocarcinoma invasive growth. In addition, its significance as a potential prognostic biomarker for intrahepatic cholangiocarcinoma patients, as well as future possibilities and challenges as a molecular target for cholangiocarcinoma therapy and/or prevention, will be critically evaluated.

  11. Periostin in Intrahepatic Cholangiocarcinoma: Pathobiological Insights and Clinical Implications

    PubMed Central

    Sirica, Alphonse E.; Almenara, Jorge A.; Li, Chao

    2014-01-01

    Periostin is a modular glycoprotein frequently observed to be a major constituent of the extracellular milieu of mass-forming intrahepatic cholangiocarcinoma and other desmoplastic malignant tumors. In intrahepatic cholangiocarcinoma, as well as in desmoplastic pancreatic ductal adenocarcinoma, periostin is overexpressed and hypersecreted in large part, if not exclusively, by cancer-associated fibroblasts within the tumor stroma. Through its interaction with specific components of the extracellular tumor matrix, particularly collagen type I and tenascin-C, and with cell surface receptors, notably integrins leading to activation of the Akt and FAK signaling pathways, this TGF-β family-inducible matricellular protein appears to be functioning as a key extracellular matrix molecule regulating such critically important and diverse malignant tumor behaviors as tumor fibrogenesis and desmoplasia, invasive malignant cell growth, chemoresistance, and metastatic colonization. This review will discuss current evidence and basic molecular mechanisms implicating periostin as a mediator of intrahepatic cholangiocarcinoma invasive growth. In addition, its significance as a potential prognostic biomarker for intrahepatic cholangiocarcinoma patients, as well as future possibilities and challenges as a molecular target for cholangiocarcinoma therapy and/or prevention, will be critically evaluated. PMID:25446840

  12. Clinicopathologic analysis of combined hepatocellular-cholangiocarcinoma according to the latest WHO classification.

    PubMed

    Akiba, Jun; Nakashima, Osamu; Hattori, Satoshi; Tanikawa, Ken; Takenaka, Miki; Nakayama, Masamich; Kondo, Reiichiro; Nomura, Yoriko; Koura, Keiko; Ueda, Kousuke; Sanada, Sakiko; Naito, Yoshiki; Yamaguchi, Rin; Yano, Hirohisa

    2013-04-01

    Combined hepatocellular-cholangiocarcinoma comprises <1% of all liver carcinomas. The histogenesis of combined hepatocellular-cholangiocarcinoma has remained unclear for many years. However, recent advances in hepatic progenitor cell (HPC) investigations have provided new insights. The concept that combined hepatocellular-cholangiocarcinoma originates from HPCs is adopted in the chapter "combined hepatocellular-cholangiocarcinoma" of the latest World Health Organization (WHO) classification. In this study, we conducted clinicopathologic analysis of combined hepatocellular-cholangiocarcinoma according to the latest WHO classification. Fifty-four cases were included in this study. Pathologic diagnosis was made according to the WHO classification. When a tumor contained plural histologic patterns, predominant histologic pattern (≥50%) was defined. Minor histologic patterns were also appended. Immunohistochemical staining with biliary markers (CK7, CK19, and EMA), hepatocyte paraffin (HepPar)-1, HPC markers (CD56, c-kit, CD133, and EpCAM), and vimentin was performed. Forty-five and 50 patients were analyzed for progression-free survival and overall survival, respectively. Ten, 1, 32, and 11 cases were diagnosed as: combined hepatocellular-cholangiocarcinoma, classical type; combined hepatocellular-cholangiocarcinoma, stem cell features, typical subtype; combined hepatocellular-cholangiocarcinoma, stem cell features, intermediate cell subtype; and combined hepatocellular-cholangiocarcinoma, stem cell features, cholangiolocellular type, respectively. Combined hepatocellular-cholangiocarcinomas usually have high expression of biliary markers. CD56, c-kit, and EpCAM were expressed to various degrees in all combined hepatocellular-cholangiocarcinomas apart from the hepatocellular carcinoma component of combined hepatocellular-cholangiocarcinoma, classical type. The expression of CD133 and vimentin was observed only in combined hepatocellular-cholangiocarcinoma, stem cell

  13. [Cholangiocarcinoma developing in printing company workers: a new type of occupational cancer].

    PubMed

    Kubo, Shoji; Takemura, Shigekazu; Sakata, Chikaharu; Urata, Yorihisa; Tanaka, Shogo; Nakanuma, Yasuni; Endo, Ginji

    2013-11-01

    The incidence of cholangiocarcinoma among the past or present workers in the department of offset color proof-printing at a printing company in Osaka was extremely high. The workers were relatively young and were exposed to several chemicals including organic solvents such as dichloromethane and 1,2-dichloropropane. Although the exact cause of cholangiocarcinoma in the patients remain unknown, it is likely that the development of cholangiocarcinoma was triggered during exposure to these chemicals. Some chemicals can act as environmental factors that lead to the development of cholangiocarcinoma. Therefore, we believe that cholangiocarcinoma is a new type of occupational cancer.

  14. Phosphorylation by p38 Mitogen-Activated Protein Kinase Promotes Estrogen Receptor α Turnover and Functional Activity via the SCFSkp2 Proteasomal Complex

    PubMed Central

    Bhatt, Shweta; Xiao, Zhen; Meng, Zhaojing

    2012-01-01

    The nuclear hormone receptor estrogen receptor α (ERα) mediates the actions of estrogens in target cells and is a master regulator of the gene expression and proliferative programs of breast cancer cells. The presence of ERα in breast cancer cells is crucial for the effectiveness of endocrine therapies, and its loss is a hallmark of endocrine-insensitive breast tumors. However, the molecular mechanisms underlying the regulation of the cellular levels of ERα are not fully understood. Our findings reveal a unique cellular pathway involving the p38 mitogen-activated protein kinase (p38MAPK)-mediated phosphorylation of ERα at Ser-294 that specifies its turnover by the SCFSkp2 proteasome complex. Consistently, we observed an inverse relationship between ERα and Skp2 or active p38MAPK in breast cancer cell lines and human tumors. ERα regulation by Skp2 was cell cycle stage dependent and critical for promoting the mitogenic effects of estradiol via ERα. Interestingly, by the knockdown of Skp2 or the inhibition of p38MAPK, we restored functional ERα protein levels and the control of gene expression and proliferation by estrogen and antiestrogen in ERα-negative breast cancer cells. Our findings highlight a novel pathway with therapeutic potential for restoring ERα and the responsiveness to endocrine therapy in some endocrine-insensitive ERα-negative breast cancers. PMID:22431515

  15. Delayed Nerve Stimulation Promotes Axon-Protective Neurofilament Phosphorylation, Accelerates Immune Cell Clearance and Enhances Remyelination In Vivo in Focally Demyelinated Nerves

    PubMed Central

    McLean, Nikki A.; Popescu, Bogdan F.; Gordon, Tessa; Zochodne, Douglas W.; Verge, Valerie M. K.

    2014-01-01

    Rapid and efficient axon remyelination aids in restoring strong electrochemical communication with end organs and in preventing axonal degeneration often observed in demyelinating neuropathies. The signals from axons that can trigger more effective remyelination in vivo are still being elucidated. Here we report the remarkable effect of delayed brief electrical nerve stimulation (ES; 1 hour @ 20 Hz 5 days post-demyelination) on ensuing reparative events in a focally demyelinated adult rat peripheral nerve. ES impacted many parameters underlying successful remyelination. It effected increased neurofilament expression and phosphorylation, both implicated in axon protection. ES increased expression of myelin basic protein (MBP) and promoted node of Ranvier re-organization, both of which coincided with the early reappearance of remyelinated axons, effects not observed at the same time points in non-stimulated demyelinated nerves. The improved ES-associated remyelination was accompanied by enhanced clearance of ED-1 positive macrophages and attenuation of glial fibrillary acidic protein expression in accompanying Schwann cells, suggesting a more rapid clearance of myelin debris and return of Schwann cells to a nonreactive myelinating state. These benefits of ES correlated with increased levels of brain derived neurotrophic factor (BDNF) in the acute demyelination zone, a key molecule in the initiation of the myelination program. In conclusion, the tremendous impact of delayed brief nerve stimulation on enhancement of the innate capacity of a focally demyelinated nerve to successfully remyelinate identifies manipulation of this axis as a novel therapeutic target for demyelinating pathologies. PMID:25310564

  16. Casein kinase II promotes target silencing by miRISC through direct phosphorylation of the DEAD-box RNA helicase CGH-1

    PubMed Central

    Alessi, Amelia F.; Khivansara, Vishal; Han, Ting; Freeberg, Mallory A.; Moresco, James J.; Tu, Patricia G.; Montoye, Eric; Yates, John R.; Karp, Xantha; Kim, John K.

    2015-01-01

    MicroRNAs (miRNAs) play essential, conserved roles in diverse developmental processes through association with the miRNA-induced silencing complex (miRISC). Whereas fundamental insights into the mechanistic framework of miRNA biogenesis and target gene silencing have been established, posttranslational modifications that affect miRISC function are less well understood. Here we report that the conserved serine/threonine kinase, casein kinase II (CK2), promotes miRISC function in Caenorhabditis elegans. CK2 inactivation results in developmental defects that phenocopy loss of miRISC cofactors and enhances the loss of miRNA function in diverse cellular contexts. Whereas CK2 is dispensable for miRNA biogenesis and the stability of miRISC cofactors, it is required for efficient miRISC target mRNA binding and silencing. Importantly, we identify the conserved DEAD-box RNA helicase, CGH-1/DDX6, as a key CK2 substrate within miRISC and demonstrate phosphorylation of a conserved N-terminal serine is required for CGH-1 function in the miRNA pathway. PMID:26669440

  17. The candidate MAP kinase phosphorylation substrate DPL-1 (DP) promotes expression of the MAP kinase phosphatase LIP-1 in C. elegans germ cells

    PubMed Central

    Lin, Baiqing; Reinke, Valerie

    2008-01-01

    The highly-conserved, commonly used MAP kinase signaling cascade plays multiple integral roles in germline development in C. elegans. Using a functional proteomic approach, we found that the transcription factor DPL-1, a component of the LIN-35(Rb)/EFL-1(E2F)/DPL-1(DP) pathway, is a candidate phosphorylation substrate of MAP kinase. Moreover, dpl-1 genetically interacts with mpk-1(MAP kinase) to control chromosome morphology in pachytene of meiosis I, as does lin-35. However, EFL-1, the canonical DPL-1 heterodimeric partner, does not have a role in this process. Interestingly, we find that DPL-1 and EFL-1, but not LIN-35, promote the expression of a negative regulator of MPK-1, the MAP kinase phosphatase LIP-1. Two E2F consensus motifs are present upstream of the lip-1 open reading frame. Therefore the Rb/E2F/DP pathway intersects with MAP kinase signaling at multiple points to regulate different aspects of C. elegans germ cell development. These two highly conserved pathways with major regulatory roles in proliferation and differentiation likely have multiple mechanisms for cross-talk during development across many species. PMID:18304523

  18. Tumor Suppressor Lzap Suppresses Wnt/β-Catenin Signaling to Promote Zebrafish Embryonic Ventral Cell Fates via the Suppression of Inhibitory Phosphorylation of Glycogen Synthase Kinase 3.

    PubMed

    Lin, Kun-Yang; Kao, Shih-Han; Lai, Chun-Ming; Chen, Ciao-Ting; Wu, Chang-Yi; Hsu, Hwei-Jan; Wang, Wen-Der

    2015-12-11

    Wnt/β-catenin signaling controls various cell fates in metazoan development, and its dysregulation is often associated with cancer formation. However, regulations of this signaling pathway are not completely understood. Here, we report that Lzap, a tumor suppressor, controls nuclear translocation of β-catenin. In zebrafish embryos disruption of lzap increases the expression of chordin (chd), which encodes a bone morphogenetic protein (BMP) antagonist that is localized in prospective dorsal cells and promotes dorsal fates. Consistently, lzap-deficient embryos with attenuated BMP signaling are dorsalized, which can be rescued by overexpression of zebrafish lzap or bmp2b or human LZAP. The expansion of chd expression in embryos lacking lzap is due to the accumulation of nuclear β-catenin in ventral cells, in which β-catenin is usually degraded. Furthermore, the activity of GSK3, a master regulator of β-catenin degradation, is suppressed in lzap-deficient embryos via inhibitory phosphorylation. Finally, we also report that a similar regulatory axis is also likely to be present in a human tongue carcinoma cell line, SAS. Our results reveal that Lzap is a novel regulator of GSK3 for the maintenance of ventral cell properties and may prevent carcinogenesis via the regulation of β-catenin degradation.

  19. Tumor Suppressor Lzap Suppresses Wnt/β-Catenin Signaling to Promote Zebrafish Embryonic Ventral Cell Fates via the Suppression of Inhibitory Phosphorylation of Glycogen Synthase Kinase 3*

    PubMed Central

    Lin, Kun-Yang; Kao, Shih-Han; Lai, Chun-Ming; Chen, Ciao-Ting; Wu, Chang-Yi; Hsu, Hwei-Jan; Wang, Wen-Der

    2015-01-01

    Wnt/β-catenin signaling controls various cell fates in metazoan development, and its dysregulation is often associated with cancer formation. However, regulations of this signaling pathway are not completely understood. Here, we report that Lzap, a tumor suppressor, controls nuclear translocation of β-catenin. In zebrafish embryos disruption of lzap increases the expression of chordin (chd), which encodes a bone morphogenetic protein (BMP) antagonist that is localized in prospective dorsal cells and promotes dorsal fates. Consistently, lzap-deficient embryos with attenuated BMP signaling are dorsalized, which can be rescued by overexpression of zebrafish lzap or bmp2b or human LZAP. The expansion of chd expression in embryos lacking lzap is due to the accumulation of nuclear β-catenin in ventral cells, in which β-catenin is usually degraded. Furthermore, the activity of GSK3, a master regulator of β-catenin degradation, is suppressed in lzap-deficient embryos via inhibitory phosphorylation. Finally, we also report that a similar regulatory axis is also likely to be present in a human tongue carcinoma cell line, SAS. Our results reveal that Lzap is a novel regulator of GSK3 for the maintenance of ventral cell properties and may prevent carcinogenesis via the regulation of β-catenin degradation. PMID:26475862

  20. Cholangiocarcinoma--an automated preliminary detection system using MLP.

    PubMed

    Logeswaran, Rajasvaran

    2009-12-01

    Cholangiocarcinoma, cancer of the bile ducts, is often diagnosed via magnetic resonance cholangiopancreatography (MRCP). Due to low resolution, noise and difficulty is actually seeing the tumor in the images, especially by examining only a single image, there has been very little development of automated systems for cholangiocarcinoma diagnosis. This paper presents a computer-aided diagnosis (CAD) system for the automated preliminary detection of the tumor using a single MRCP image. The multi-stage system employs algorithms and techniques that correspond to the radiological diagnosis characteristics employed by doctors. A popular artificial neural network, the multi-layer perceptron (MLP), is used for decision making to differentiate images with cholangiocarcinoma from those without. The test results achieved was 94% when differentiating only healthy and tumor images, and 88% in a robust multi-disease test where the system had to identify the tumor images from a large set of images containing common biliary diseases.

  1. New insights into the molecular pathogenesis of intrahepatic cholangiocarcinoma

    PubMed Central

    Patel, Tushar

    2013-01-01

    Intrahepatic cholangiocarcinoma is an aggressive malignancy and is one of the most devastating cancers of the gastrointestinal tract. The molecular mechanisms contributing to the pathogenesis of these cancers are not well understood. The recognition and distinction of these cancers from other tumors such as extrahepatic or ductal cholangiocarcinoma and hepatocellular carcinoma have been important in defining the pathogenesis. New insights into molecular mechanisms contributing to disease pathogenesis are emerging from recent epidemiological, genome-wide profiling and laboratory based studies. These have contributed to an improved understanding of risk factors, genetic mutations and pathophysiological mechanisms that are associated with these tumors. The contribution of well-established risk factors such as biliary tract inflammation and key signaling pathways involved in intrahepatic cholangiocarcinoma are being further defined. These new insights have several important implications for both molecular diagnosis and therapy of these cancers. PMID:24145988

  2. Hepatolithiasis and intrahepatic cholangiocarcinoma: A review

    PubMed Central

    Kim, Hyo Jung; Kim, Jae Seon; Joo, Moon Kyung; Lee, Beom Jae; Kim, Ji Hoon; Yeon, Jong Eun; Park, Jong-Jae; Byun, Kwan Soo; Bak, Young-Tae

    2015-01-01

    Although the incidence of hepatolithiasis is decreasing as the pattern of gallstone disease changes in Asia, the prevalence of hepatolithiasis is persistently high, especially in Far Eastern countries. Hepatolithiasis is an established risk factor for cholangiocarcinoma (CCA), and chronic proliferative inflammation may be involved in biliary carcinogenesis and in inducing the upregulation of cell-proliferating factors. With the use of advanced imaging modalities, there has been much improvement in the management of hepatolithiasis and the diagnosis of hepatolithiasis-associated CCA (HL-CCA). However, there are many problems in managing the strictures in hepatolithiasis and differentiating them from infiltrating types of CCA. Surgical resection is recommended in cases of single lobe hepatolithiasis with atrophy, uncontrolled stricture, symptom duration of more than 10 years, and long history of biliary-enteric anastomosis. Even after resection, patients should be followed with caution for development of HL-CCA, because HL-CCA is an independent prognostic factor for survival. It is not yet clear whether hepatic resection can reduce the occurrence of subsequent HL-CCA. Furthermore, there are no consistent findings regarding prediction of subsequent HL-CCA in patients with hepatolithiasis. In the management of hepatolithiasis, important factors are the reduction of recurrence of cholangitis and suspicion of unrecognized HL-CCA. PMID:26730152

  3. Radiofrequency Ablation of Intrahepatic Cholangiocarcinoma: Preliminary Experience

    SciTech Connect

    Carrafiello, Gianpaolo Lagana, Domenico; Cotta, Elisa; Mangini, Monica; Fontana, Federico; Bandiera, Francesca; Fugazzola, Carlo

    2010-08-15

    The purpose of this study was to evaluate the safety and efficacy of percutaneous ultrasound (US)-guided radiofrequency ablation (RFA) in patients with intrahepatic cholangiocarcinoma (ICCA) in a small, nonrandomized series. From February 2004 to July 2008, six patients (four men and two women; mean age 69.8 years [range 48 to 83]) with ICCA underwent percutaneous US-guided RFA. Preintervetional transarterial embolization was performed in two cases to decrease heat dispersion during RFA in order to increase the area of ablation. The efficacy of RFA was evaluated using contrast-enhanced dynamic computed tomography (CT) 1 month after treatment and then every 3 months thereafter. Nine RFA sessions were performed for six solid hepatic tumors in six patients. The duration of follow-up ranged from 13 to 21 months (mean 17.5). Posttreatment CT showed total necrosis in four of six tumors after one or two RFA sessions. Residual tumor was observed in two patients with larger tumors (5 and 5.8 cm in diameter). All patients tolerated the procedure, and there with no major complications. Only 1 patient developed post-RFA syndrome (pain, fever, malaise, and leukocytosis), which resolved with oral administration of acetaminophen. Percutaneous RFA is a safe and effective treatment for patients with hepatic tumors: It is ideally suited for those who are not eligible for surgery. Long-term follow-up data regarding local and systemic recurrence and survival are still needed.

  4. Intrahepatic cholangiocarcinoma: current management and emerging therapies.

    PubMed

    Rahnemai-Azar, Amir A; Weisbrod, Allison B; Dillhoff, Mary; Schmidt, Carl; Pawlik, Timothy M

    2017-05-01

    Intrahepatic cholangiocarcinoma (iCCA) is a malignancy with an increasing incidence and a high-case fatality. While surgery offers the best hope at long-term survival, only one-third of tumors are amenable to surgical resection at the time of the diagnosis. Unfortunately, conventional chemotherapy offers limited survival benefit in the management of unresectable or metastatic disease. Recent advances in understanding the molecular pathogenesis of iCCA and the use of next-generation sequencing techniques have provided a chance to identify 'target-able' molecular aberrations. These novel molecular therapies offer the promise to personalize therapy for patients with iCCA and, in turn, improve the outcomes of patients. Area covered: We herein review the current management options for iCCA with a focus on defining both established and emerging therapies. Expert commentary: Surgical resection remains as an only hope for cure in iCCA patients. However, frequently the diagnosis is delayed till advanced stages when surgery cannot be offered; signifying the urge for specific diagnostic tumor biomarkers and targeted therapies. New advances in genomic profiling have contributed to a better understanding of the landscape of molecular alterations in iCCA and offer hope for the development of novel diagnostic biomarkers and targeted therapies.

  5. Cholangiocarcinoma: Biology, Clinical Management, and Pharmacological Perspectives

    PubMed Central

    Macias, Rocio I. R.

    2014-01-01

    Cholangiocarcinoma (CCA), or tumor of the biliary tree, is a rare and heterogeneous group of malignancies associated with a very poor prognosis. Depending on their localization along the biliary tree, CCAs are classified as intrahepatic, perihilar, and distal, and these subtypes are now considered different entities that differ in tumor biology, the staging system, management, and prognosis. When diagnosed, an evaluation by a multidisciplinary team is essential; the team must decide on the best therapeutic option. Surgical resection of tumors with negative margins is the best option for all subtypes of CCA, although this is only achieved in less than 50% of cases. Five-year survival rates have increased in the recent past owing to improvements in imaging techniques, which permits resectability to be predicted more accurately, and in surgery. Chemotherapy and radiotherapy are relatively ineffective in treating nonoperable tumors and the resistance of CCA to these therapies is a major problem. Although the combination of gemcitabine plus platinum derivatives is the pharmacological treatment most widely used, to date there is no standard chemotherapy, and new combinations with targeted drugs are currently being tested in ongoing clinical trials. This review summarizes the biology, clinical management, and pharmacological perspectives of these complex tumors. PMID:27335842

  6. Pathological aspects of so called "hilar cholangiocarcinoma"

    PubMed Central

    Castellano-Megías, Víctor M; Ibarrola-de Andrés, Carolina; Colina-Ruizdelgado, Francisco

    2013-01-01

    Cholangiocarcinoma (CC) arising from the large intrahepatic bile ducts and extrahepatic hilar bile ducts share clinicopathological features and have been called hilar and perihilar CC as a group. However, “hilar and perihilar CC” are also used to refer exclusively to the intrahepatic hilar type CC or, more commonly, the extrahepatic hilar CC. Grossly, a major distinction can be made between papillary and non-papillary tumors. Histologically, most hilar CCs are well to moderately differentiated conventional type (biliary) carcinomas. Immunohistochemically, CK7, CK20, CEA and MUC1 are normally expressed, being MUC2 positive in less than 50% of cases. Two main premalignant lesions are known: biliary intraepithelial neoplasia (BilIN) and intraductal papillary neoplasm of the biliary tract (IPNB). IPNB includes the lesions previously named biliary papillomatosis and papillary carcinoma. A series of 29 resected hilar CC from our archives is reviewed. Most (82.8%) were conventional type adenocarcinomas, mostly well to moderately differentiated, although with a broad morphological spectrum; three cases exhibited a poorly differentiated cell component resembling signet ring cells. IPNB was observed in 5 (17.2%), four of them with an associated invasive carcinoma. A clear cell type carcinoma, an adenosquamous carcinoma and two gastric foveolar type carcinomas were observed. PMID:23919110

  7. Multidisciplinary Care of Patients with Intrahepatic Cholangiocarcinoma: Updates in Management

    PubMed Central

    Lafaro, Kelly J.; Cosgrove, David; Geschwind, Jean-Francois H.; Kamel, Ihab; Herman, Joseph M.; Pawlik, Timothy M.

    2015-01-01

    Cholangiocarcinoma is a highly fatal primary cancer of the bile ducts which arises from malignant transformation of bile duct epithelium. While being an uncommon malignancy with an annual incidence in the United States of 5000 new cases, the incidence has been increasing over the past 30 years and comprises 3% of all gastrointestinal cancers. Cholangiocarcinoma can be classified into intrahepatic (ICC) and extrahepatic (including hilar and distal bile duct) according to its anatomic location within the biliary tree with respect to the liver. This paper reviews the management of ICC, focusing on the epidemiology, risk factors, diagnosis, and surgical and nonsurgical management. PMID:26089873

  8. An Autopsy Case of Lepidic Pulmonary Metastasis from Cholangiocarcinoma

    PubMed Central

    Nagayoshi, Yohsuke; Yamamoto, Kazuko; Hashimoto, Satoru; Hisatomi, Keiko; Doi, Seiji; Nagashima, Seiji; Kurohama, Hirokazu; Ito, Masahiro; Takazono, Takahiro; Nakamura, Shigeki; Miyazaki, Taiga; Kohno, Shigeru

    2016-01-01

    We herein report the first case of pulmonary metastasis with lepidic growth that originated from cholangiocarcinoma. A 77-year-old man was admitted to our hospital due to exertional dyspnea and liver dysfunction. Computed tomography showed widespread infiltration and a ground-glass opacity in the lung and dilation of the intrahepatic bile duct. The pulmonary lesion progressed rapidly, and the patient died of respiratory failure. Cholangiocarcinoma and lepidic pulmonary metastasis were pathologically diagnosed by an autopsy. Lepidic pulmonary growth is an atypical pattern of metastasis, and immunopathological staining is useful to distinguish pulmonary metastasis from extrapulmonary cancer and primary pulmonary adenocarcinoma. PMID:27725547

  9. cSrc and Her2 Signaling Pathways Cooperate with Estrogen to Promote ER Phosphorylation, Ubiquitination and Proteolysis in ER Negative Breast Cancers

    DTIC Science & Technology

    2007-03-01

    the estrogen receptor through phosphorylation by mitogen- activated protein kinase. Science 270:1491-1494. 31. Ignar -Trowbridge,D.M., Nelson,K.G...phosphorylation. Hormonal dependence and consequence on specific DNA binding. J Biol Chem 1992;267:7263–8. 54. Ignar -Trowbridge DM, Teng CT, Ross KA

  10. Cholangiocarcinomas induced by feeding 3'-methyl-4-dimethylaminoazobenzene to rats. Histopathology and ultrastructure.

    PubMed Central

    Reddy, K. P.; Buschmann, R. J.; Chomet, B.

    1977-01-01

    Thirty-three male Sprague-Dawley rats were fed a carcinogenic (0.064% 3'-methyl-4-dimethylaminoazobenzene, 3'-Me-DAB) ground meal normal diet. After 12 weeks the ground meal diet was replaced with a normal pellet diet, and the 30 surviving animals were divided into three equal groups. One group was sacrificed at the twelfth week and the other groups 4 and 8 weeks later. Control animals were also run. Based on previous studies which used "tumor-promoting" diets and 3'-Me-DAB, we expected a less than 100% incidence of predominantly hepatocellular carcinomas. However, we found mucin-producing cholangiocarcinomas in all 30 animals and, in addition, a small hepatocellular component in 3 of the animals. By electron microscopy the intestinal mucosal features of microvillous border cells, goblet cells, and endocrine-like cells were found. We suggest that the tumors produced as described here provide a good animal model of mucin-producing cholangiocarcinomas. Images Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 1 Figure 2 PMID:192081

  11. The PD-1/PD-L1 axis may be aberrantly activated in occupational cholangiocarcinoma.

    PubMed

    Sato, Yasunori; Kinoshita, Masahiko; Takemura, Shigekazu; Tanaka, Shogo; Hamano, Genya; Nakamori, Shoji; Fujikawa, Masahiro; Sugawara, Yasuhiko; Yamamoto, Takatsugu; Arimoto, Akira; Yamamura, Minako; Sasaki, Motoko; Harada, Kenichi; Nakanuma, Yasuni; Kubo, Shoji

    2017-03-01

    An outbreak of cholangiocarcinoma in a printing company was reported in Japan, and these cases were regarded as an occupational disease (occupational cholangiocarcinoma). This study examined the expression status of programmed death-1 (PD-1) and programmed death-ligand 1 (PD-L1) in occupational cholangiocarcinoma. Immunostaining of PD-1, PD-L1, CD3, CD8, and CD163 was performed using tissue sections of occupational cholangiocarcinoma (n = 10), and the results were compared with those of control cases consisting of intrahepatic (n = 23) and extrahepatic (n = 45) cholangiocarcinoma. Carcinoma cells expressed PD-L1 in all cases of occupational cholangiocarcinoma, whereas the detection of PD-L1 expression in cholangiocarcinoma cells was limited to a low number of cases (less than 10%) in the control subjects. In cases of occupational cholangiocarcinoma, occasional PD-L1 expression was also noted in precancerous/preinvasive lesions such as biliary intraepithelial neoplasia and intraductal papillary neoplasm of the bile duct. Additionally, tumor-associated macrophages and tumor-infiltrating T cells expressed PD-L1 and PD-1, respectively. The number of PD-L1-positive mononuclear cells, PD-1-positive lymphocytes, and CD8-positive lymphocytes infiltrating within the tumor was significantly higher in occupational cholangiocarcinoma compared with that in control cases. These results indicate that immune escape via the PD-1/PD-L1 axis may be occurring in occupational cholangiocarcinoma.

  12. Targeting PDGFR-β in Cholangiocarcinoma

    PubMed Central

    Fingas, Christian D; Mertens, Joachim C; Razumilava, Nataliya; Bronk, Steven F; Sirica, Alphonse E; Gores, Gregory J

    2011-01-01

    Background Cholangiocarcinomas (CCAs) are highly desmoplastic neoplasms with a tumor microenvironment plentiful in myofibroblasts (MFBs). MFB-derived PDGF-BB survival signaling is a mediator of CCA cell resistance to apoptotic stimuli. This raises the concept that targeting PDGFR-β, a cognate receptor of PDGF-BB, represents a potential strategy for the treatment of human CCA. Aims Herein, we examine a role for inhibiting PDGFR-β in restoring CCA cell sensitivity to apoptotic stimuli in vitro and in vivo. Methods We employed human CCA samples from 41 patients (19 intrahepatic and 22 extrahepatic CCA samples), the human CCA cell lines KMCH-1 and HUCCT-1 as well as shPDGFR-β-KMCH-1 and human myofibroblastic LX-2 cells for these studies. In vivo-experiments were conducted using a syngeneic rat orthotopic CCA model. Results Of several MFB-derived growth factors profiled, PDGF-BB and CTGF were most abundantly expressed; however, only PDGF-BB attenuated TRAIL cytotoxicity. Co-culturing CCA cells with PDGF-BB-secreting MFBs significantly decreased TRAIL-induced CCA cell apoptosis as compared to monoculture conditions; this cytoprotective effect was abrogated in the presence of the tyrosine kinase inhibitors imatinib mesylate or linifanib, which inhibit PDGFR-β. Consistent with these findings, MFB-imparted cytoprotection also was abolished when PDGFR-β was knocked down as demonstrated in shPDGFR-β-KMCH-1 cells. Finally, administration of imatinib mesylate increased CCA cell apoptosis and reduced tumor growth in a rodent in vivo-CCA model that mimics the human disease. Conclusions Targeting PDGFR-β sensitizes CCA cells to apoptotic stimuli and appears to be therapeutic in vivo. PMID:22133064

  13. Concurrent Chemoradiotherapy in Resected Extrahepatic Cholangiocarcinoma

    SciTech Connect

    Nelson, John W.; Ghafoori, A. Paiman; Willett, Christopher G.; Tyler, Douglas S.; Pappas, Theodore N.; Clary, Bryan M.; Hurwitz, Herbert I.; Bendell, Johanna C.; Morse, Michael A.; Clough, Robert W.; Czito, Brian G.

    2009-01-01

    Purpose: Extrahepatic cholangiocarcinoma is a rare malignancy. Despite radical resection, survival remains poor, with high rates of local and distant failure. To clarify the role of radiotherapy with chemotherapy, we performed a retrospective analysis of resected patients who had undergone chemoradiotherapy. Methods and Materials: A total of 45 patients (13 with proximal and 32 with distal disease) underwent resection plus radiotherapy (median dose, 50.4 Gy). All but 1 patient received concurrent fluoropyrimidine-based chemotherapy. The median follow-up was 30 months for all patients and 40 months for survivors. Results: Of the 45 patients, 33 underwent adjuvant radiotherapy, and 12 were treated neoadjuvantly. The 5-year actuarial overall survival, disease-free survival, metastasis-free survival, and locoregional control rates were 33%, 37%, 42%, and 78%, respectively. The median survival was 34 months. No patient died perioperatively. Patient age {<=}60 years and perineural involvement adversely affected survival on univariate analysis. Patients undergoing R0 resection had a significantly improved rate of local control but no survival advantage. Despite having more advanced disease at presentation, patients treated neoadjuvantly had a longer survival (5-year survival 53% vs. 23%, p = 0.16) and similar rates of Grade 2-3 surgical morbidity (16% vs. 33%, p = 0.24) compared with those treated in the postoperative setting. Conclusion: These study results suggest a possible local control benefit from chemoradiotherapy combined with surgery in patients with advanced, resected biliary cancer. Furthermore, our results suggest that a treatment strategy that includes preoperative chemoradiotherapy might result in improved tumor resectability with similar surgical morbidity compared with patients treated postoperatively, as well as potentially improved survival outcomes. Distant failure remains a significant failure pattern, suggesting the need for more effective systemic

  14. CONCURRENT CHEMORADIOTHERAPY IN RESECTED EXTRAHEPATIC CHOLANGIOCARCINOMA

    PubMed Central

    Nelson, John W.; Ghafoori, A. Paiman; Willett, Christopher G.; Tyler, Douglas S.; Pappas, Theodore N.; Clary, Bryan M.; Hurwitz, Herbert I.; Bendell, Johanna C.; Morse, Michael A.; Clough, Robert W.; Czito, Brian G.

    2014-01-01

    Purpose Extrahepatic cholangiocarcinoma is a rare malignancy. Despite radical resection, survival remains poor, with high rates of local and distant failure. To clarify the role of radiotherapy with chemotherapy, we performed a retrospective analysis of resected patients who had undergone chemoradiotherapy. Methods and Materials A total of 45 patients (13 with proximal and 32 with distal disease) underwent resection plus radiotherapy (median dose, 50.4 Gy). All but 1 patient received concurrent fluoropyrimidine-based chemotherapy. The median follow-up was 30 months for all patients and 40 months for survivors. Results Of the 45 patients, 33 underwent adjuvant radiotherapy, and 12 were treated neoadjuvantly. The 5-year actuarial overall survival, disease-free survival, metastasis-free survival, and locoregional control rates were 33%, 37%, 42%, and 78%, respectively. The median survival was 34 months. No patient died perioperatively. Patient age ≤60 years and perineural involvement adversely affected survival on univariate analysis. Patients undergoing R0 resection had a significantly improved rate of local control but no survival advantage. Despite having more advanced disease at presentation, patients treated neoadjuvantly had a longer survival (5-year survival 53% vs. 23%, p = 0.16) and similar rates of Grade 2–3 surgical morbidity (16% vs. 33%, p = 0.24) compared with those treated in the postoperative setting. Conclusion These study results suggest a possible local control benefit from chemoradiotherapy combined with surgery in patients with advanced, resected biliary cancer. Furthermore, our results suggest that a treatment strategy that includes preoperative chemoradiotherapy might result in improved tumor resectability with similar surgical morbidity compared with patients treated postoperatively, as well as potentially improved survival outcomes. Distant failure remains a significant failure pattern, suggesting the need for more effective systemic

  15. Genetic Factors in the Pathogenesis of Cholangiocarcinoma

    PubMed Central

    Wadsworth, Christopher A.; Dixon, Peter H.; Wong, Jason H.; Chapman, Michael H.; McKay, Siobhan C.; Sharif, Amar; Spalding, Duncan R.; Pereira, Stephen P.; Thomas, Howard C.; Taylor-Robinson, Simon D.; Whittaker, John; Williamson, Catherine; Khan, Shahid A.

    2011-01-01

    Background Cholangiocarcinoma (CC) is increasing in incidence, but its pathogenesis remains poorly understood. Chronic inflammation of the bile duct and cholestasis are major risk factors, but most cases in the West are sporadic. Genetic polymorphisms in biliary transporter proteins have been implicated in benign biliary disease and, in the case of progressive familial cholestasis, have been associated with childhood onset of CC. In the current study, five biologically plausible candidate genes were investigated: ABCB11 (BSEP), ABCB4 (MDR3), ABCC2 (MRP2), ATP8B1 (FIC1) and NR1H4 (FXR). Methods DNA was collected from 172 Caucasian individuals with confirmed CC. A control cohort of healthy Caucasians was formed. Seventy-three SNPs were selected using the HapMap database to capture genetic variation around the five candidate loci. Genotyping was undertaken with a competitive PCR-based system. Confirmation of Hardy-Weinberg equilibrium and Cochran-Armitage trend testing were performed using PLINK. Haplotype frequencies were compared using haplo.stats. Results All 73 SNPs were in Hardy-Weinberg equilibrium. Four SNPs in ABCB11 were associated with altered susceptibility to CC, including the V444A polymorphism, but these associations did not retain statistical significance after Bonferroni correction for multiple testing. Haplotype analysis of the genotyped SNPs in ATP8B1 identified significant differences in frequencies between cases and controls (global p value of 0.005). Conclusion Haplotypes in ATP8B1 demonstrated a significant difference between CC and control groups. There was a trend towards significant association of V444A with CC. Given the biological plausibility of polymorphisms in ABCB11 and ATP8B1 as risk modifiers for CC, further study in a validation cohort is required. PMID:21691113

  16. Recurrence after operative management of intrahepatic cholangiocarcinoma.

    PubMed

    Hyder, Omar; Hatzaras, Ioannis; Sotiropoulos, Georgios C; Paul, Andreas; Alexandrescu, Sorin; Marques, Hugo; Pulitano, Carlo; Barroso, Eduardo; Clary, Bryan M; Aldrighetti, Luca; Ferrone, Cristina R; Zhu, Andrew X; Bauer, Todd W; Walters, Dustin M; Groeschl, Ryan; Gamblin, T Clark; Marsh, J Wallis; Nguyen, Kevin T; Turley, Ryan; Popescu, Irinel; Hubert, Catherine; Meyer, Stephanie; Choti, Michael A; Gigot, Jean-Francois; Mentha, Gilles; Pawlik, Timothy M

    2013-06-01

    Data on recurrence after operation for intrahepatic cholangiocarcinoma (ICC) are limited. We sought to investigate rates and patterns of recurrence in patients after operative intervention for ICC. We identified 301 patients who underwent operation for ICC between 1990 and 2011 from an international, multi-institutional database. Clinicopathologic data, recurrence patterns, and recurrence-free survival (RFS) were analyzed. During the median follow up duration of 31 months (range 1-208), 53.5% developed a recurrence. Median RFS was 20.2 months and 5-year actuarial disease-free survival, 32.1%. The most common site for initial recurrence after operation of ICC was intrahepatic (n = 98; 60.9%), followed by simultaneous intra- and extrahepatic disease (n = 30; 18.6%); 33 (21.0%) patients developed extrahepatic recurrence only as the first site of recurrence. Macrovascular invasion (hazard ratio [HR], 2.08; 95% confidence interval [CI], 1.34-3.21; P < .001), nodal metastasis (HR, 1.55; 95% CI, 1.01-2.45; P = .04), unknown nodal status (HR, 1.57; 95% CI, 1.10-2.25; P = .04), and tumor size ≥ 5 cm (HR, 1.84; 95% CI, 1.28-2.65; P < .001) were independently associated with increased risk of recurrence. Patients were assigned a clinical score from 0 to 3 according to the presence of these risk factors. The 5-year RFS for patients with scores of 0, 1, 2, and 3 was 61.8%, 36.2%, 19.5%, and 9.6%, respectively. Recurrence after operative intervention for ICC was common. Disease recurred both at intra- and extrahepatic sites with roughly the same frequency. Factors such as lymph node metastasis, tumor size, and vascular invasion predict highest risk of recurrence. Copyright © 2013 Mosby, Inc. All rights reserved.

  17. Recurrence after operative management of intrahepatic cholangiocarcinoma

    PubMed Central

    Hyder, Omar; Hatzaras, Ioannis; Sotiropoulos, Georgios C.; Paul, Andreas; Alexandrescu, Sorin; Marques, Hugo; Pulitano, Carlo; Barroso, Eduardo; Clary, Bryan M.; Aldrighetti, Luca; Ferrone, Cristina R.; Zhu, Andrew X.; Bauer, Todd W.; Walters, Dustin M.; Groeschl, Ryan; Gamblin, T. Clark; Marsh, J. Wallis; Nguyen, Kevin T.; Turley, Ryan; Popescu, Irinel; Hubert, Catherine; Meyer, Stephanie; Choti, Michael A.; Gigot, Jean-Francois; Mentha, Gilles; Pawlik, Timothy M.

    2014-01-01

    Introduction Data on recurrence after operation for intrahepatic cholangiocarcinoma (ICC) are limited. We sought to investigate rates and patterns of recurrence in patients after operative intervention for ICC. Methods We identified 301 patients who underwent operation for ICC between 1990 and 2011 from an international, multi-institutional database. Clinicopathologic data, recurrence patterns, and recurrence-free survival (RFS) were analyzed. Results During the median follow up duration of 31 months (range 1–208), 53.5% developed a recurrence. Median RFS was 20.2 months and 5-year actuarial disease-free survival, 32.1%. The most common site for initial recurrence after operation of ICC was intrahepatic (n = 98; 60.9%), followed by simultaneous intra- and extrahepatic disease (n = 30; 18.6%); 33 (21.0%) patients developed extra-hepatic recurrence only as the first site of recurrence. Macrovascular invasion (hazard ratio [HR], 2.08; 95% confidence interval [CI], 1.34–3.21; P <.001), nodal metastasis (HR, 1.55; 95% CI, 1.01–2.45; P = .04), unknown nodal status (HR, 1.57; 95% CI, 1.10–2.25; P = .04), and tumor size ≥5 cm (HR, 1.84; 95% CI, 1.28–2.65; P <.001) were independently associated with increased risk of recurrence. Patients were assigned a clinical score from 0 to 3 according to the presence of these risk factors. The 5-year RFS for patients with scores of 0, 1, 2, and 3 was 61.8%, 36.2%, 19.5%, and 9.6%, respectively. Conclusion Recurrence after operative intervention for ICC was common. Disease recurred both at intra-and extrahepatic sites with roughly the same frequency. Factors such as lymph node metastasis, tumor size, and vascular invasion predict highest risk of recurrence. PMID:23499016

  18. Hepatitis C virus infection of cholangiocarcinoma cell lines.

    PubMed

    Fletcher, Nicola F; Humphreys, Elizabeth; Jennings, Elliott; Osburn, William; Lissauer, Samantha; Wilson, Garrick K; van IJzendoorn, Sven C D; Baumert, Thomas F; Balfe, Peter; Afford, Simon; McKeating, Jane A

    2015-06-01

    Hepatitis C virus (HCV) infects the liver and hepatocytes are the major cell type supporting viral replication. Hepatocytes and cholangiocytes derive from a common hepatic progenitor cell that proliferates during inflammatory conditions, raising the possibility that cholangiocytes may support HCV replication and contribute to the hepatic reservoir. We screened cholangiocytes along with a panel of cholangiocarcinoma-derived cell lines for their ability to support HCV entry and replication. While primary cholangiocytes were refractory to infection and lacked expression of several entry factors, two cholangiocarcinoma lines, CC-LP-1 and Sk-ChA-1, supported efficient HCV entry; furthermore, Sk-ChA-1 cells supported full virus replication. In vivo cholangiocarcinomas expressed all of the essential HCV entry factors; however, cholangiocytes adjacent to the tumour and in normal tissue showed a similar pattern of receptor expression to ex vivo isolated cholangiocytes, lacking SR-BI expression, explaining their inability to support infection. This study provides the first report that HCV can infect cholangiocarcinoma cells and suggests that these heterogeneous tumours may provide a reservoir for HCV replication in vivo.

  19. Association of MMP7 -181A→G Promoter Polymorphism with Gastric Cancer Risk: INFLUENCE OF NICOTINE IN DIFFERENTIAL ALLELE-SPECIFIC TRANSCRIPTION VIA INCREASED PHOSPHORYLATION OF cAMP-RESPONSE ELEMENT-BINDING PROTEIN (CREB).

    PubMed

    Kesh, Kousik; Subramanian, Lakshmi; Ghosh, Nillu; Gupta, Vinayak; Gupta, Arnab; Bhattacharya, Samir; Mahapatra, Nitish R; Swarnakar, Snehasikta

    2015-06-05

    Elevated expression of matrix metalloproteinase7 (MMP7) has been demonstrated to play a pivotal role in cancer invasion. The -181A→G (rs11568818) polymorphism in the MMP7 promoter modulates gene expression and possibly affects cancer progression. Here, we evaluated the impact of -181A→G polymorphism on MMP7 promoter activity and its association with gastric cancer risk in eastern Indian case-control cohorts (n = 520). The GG genotype as compared with the AA genotype was predisposed (p = 0.02; odds ratio = 1.9, 95% confidence interval = 1.1-3.3) to gastric cancer risk. Stratification analysis showed that tobacco addiction enhanced gastric cancer risk in GG subjects when compared with AA subjects (p = 0.03, odds ratio = 2.46, and 95% confidence interval = 1.07-5.68). Meta-analysis revealed that tobacco enhanced the risk for cancer more markedly in AG and GG carriers. Activity and expression of MMP7 were significantly higher in GG than in AA carriers. In support, MMP7 promoter-reporter assays showed greater transcriptional activity toward A to G transition under basal/nicotine-induced/cAMP-response element-binding protein (CREB) overexpressed conditions in gastric adenocarcinoma cells. Moreover, nicotine (a major component of tobacco) treatment significantly up-regulated MMP7 expression due to enhanced CREB phosphorylation followed by its nuclear translocation in gastric adenocarcinoma cells. Furthermore, chromatin immunoprecipitation experiments revealed higher binding of phosphorylated CREB with the -181G than the -181A allele. Altogether, specific binding of phosphorylated CREB to the G allele-carrying promoter enhances MMP7 gene expression that is further augmented by nicotine due to increased CREB phosphorylation and thereby increases the risk for gastric cancer.

  20. Studies on deoxyribonucleic acids and related compounds. V. Synthesis of pentadecanucleotide duplex containing the ideal Pribnow sequence of promoter by the phosphotriester method using a new phosphorylating reagent.

    PubMed Central

    Ohtsuka, E; Taniyama, Y; Marumoto, R; Sato, H; Hirosaki, H; Ikehara, M

    1982-01-01

    A phosphorylating reagent o-chlorophenyl phosphoro-p-anisi-dochloridate was synthesized to phosphorylate the 3'-hydroxyl group of N, 5'-protected deoxynucleosides. These nucleotides served as 3'-terminal units for the synthesis of oligonucleotide blocks. By condensation of these oligonucleotide blocks the partially complementary deoxypentadecanucleotides dAGCTTATAATGC-TCG and dAGCTCGAGCATTATA, which contained the ideal Pribnow sequence TATAATG, were synthesized. PMID:7079181

  1. Growth hormone suppresses the expression of IGFBP-5, and promotes the IGF-I-induced phosphorylation of Akt in bovine mammary epithelial cells.

    PubMed

    Sakamoto, Kazuhito; Yano, Tomoki; Kobayashi, Takuya; Hagino, Akihiko; Aso, Hisashi; Obara, Yoshiaki

    2007-05-01

    Growth hormone (GH) plays a specific role to inhibit apoptosis in the bovine mammary gland through the insulin-like growth factor (IGF)-I system, however, the mechanism of GH action is poorly understood. In this study, we show that GH dramatically inhibits the expression of IGFBP-5, and GH along with IGF-I enhanced the phosphorylation of Akt through the reduction of IGF binding protein (IGFBP)-5. To determine how GH affects Akt through IGF-I in bovine mammary epithelial cells (BMECs), we examined the phosphorylation of Akt in GH treated BMECs and found that IGF-I induced phosphorylation of Akt was significantly enhanced by the treatment with GH. We demonstrated that GH reduces mRNA and protein expression of IGFBP-5 in BMECs, but it does not affect the expression of IGFBP-3. To determine that the enhanced effect of the Akt phosphorylation by the treatment of GH is due to the inhibition of the expression of IGFBP-5, we examined the effect of IGFBP-3 and -5 on the phosphorylation of Akt through IGF-I in the GH-treated BMECs. The phosphorylation of Akt was inhibited in a dose-dependent manner when IGFBP-5 was added at varying concentrations and was also inhibited in the presence of IGFBP-3. The results of this study suggest that GH plays an important role on mammary gland involution in bovine mammary epithelial cells.

  2. Cell death/proliferation roles for nc886, a non-coding RNA, in the protein kinase R pathway in cholangiocarcinoma.

    PubMed

    Kunkeaw, N; Jeon, S H; Lee, K; Johnson, B H; Tanasanvimon, S; Javle, M; Pairojkul, C; Chamgramol, Y; Wongfieng, W; Gong, B; Leelayuwat, C; Lee, Y S

    2013-08-08

    We have recently identified nc886 (pre-miR-886 or vtRNA2-1) as a novel type of non-coding RNA that inhibits activation of protein kinase R (PKR). PKR's pro-apoptotic role through eukaryotic initiation factor 2 α (eIF2α) phosphorylation is well established in the host defense against viral infection. Paradoxically, some cancer patients have elevated PKR activity; however, its cause and consequence are not understood. Initially, we evaluated the expression of nc886, PKR and eIF2α in non-malignant cholangiocyte and cholangiocarcinoma (CCA) cells. nc886 is repressed in CCA cells and this repression is the cause of PKR's activation therein. nc886 alone is necessary and sufficient for suppression of PKR via direct physical interaction. Consistently, artificial suppression of nc886 in cholangiocyte cells activates the canonical PKR/eIF2α cell death pathway, suggesting a potential significance of the nc886 suppression and the consequent PKR activation in eliminating pre-malignant cells during tumorigenesis. In comparison, active PKR in CCA cells does not induce phospho-eIF2α nor apoptosis, but promotes the pro-survival nuclear factor-κB pathway. Thus, PKR has a dual life or death role during tumorigenesis. Similarly to the CCA cell lines, nc886 tends to be decreased but PKR tends to be activated in our clinical samples from CCA patients. Collectively from our data, we propose a tumor surveillance model for nc886's role in the PKR pathway during tumorigenesis.

  3. Pepper suppressor of the G2 allele of skp1 interacts with the receptor-like cytoplasmic kinase1 and type III effector AvrBsT and promotes the hypersensitive cell death response in a phosphorylation-dependent manner.

    PubMed

    Kim, Nak Hyun; Kim, Dae Sung; Chung, Eui Hwan; Hwang, Byung Kook

    2014-05-01

    Xanthomonas campestris pv vesicatoria type III effector protein, AvrBsT, triggers hypersensitive cell death in pepper (Capsicum annuum). Here, we have identified the pepper SGT1 (for suppressor of the G2 allele of skp1) as a host interactor of AvrBsT and also the pepper PIK1 (for receptor-like cytoplasmic kinase1). PIK1 specifically phosphorylates SGT1 and AvrBsT in vitro. AvrBsT specifically binds to the CHORD-containing protein and SGT1 domain of SGT1, resulting in the inhibition of PIK1-mediated SGT1 phosphorylation and subsequent nuclear transport of the SGT1-PIK1 complex. Liquid chromatography-tandem mass spectrometry of the proteolytic peptides of SGT1 identified the residues serine-98 and serine-279 of SGT1 as the major PIK1-mediated phosphorylation sites. Site-directed mutagenesis of SGT1 revealed that the identified SGT1 phosphorylation sites are responsible for the activation of AvrBsT-triggered cell death in planta. SGT1 forms a heterotrimeric complex with both AvrBsT and PIK1 exclusively in the cytoplasm. Agrobacterium tumefaciens-mediated coexpression of SGT1 and PIK1 with avrBsT promotes avrBsT-triggered cell death in Nicotiana benthamiana, dependent on PIK1. Virus-induced silencing of SGT1 and/or PIK1 compromises avrBsT-triggered cell death, hydrogen peroxide production, defense gene induction, and salicylic acid accumulation, leading to the enhanced bacterial pathogen growth in pepper. Together, these results suggest that SGT1 interacts with PIK1 and the bacterial effector protein AvrBsT and promotes the hypersensitive cell death associated with PIK1-mediated phosphorylation in plants.

  4. Modulatory role of garlicin in migration and invasion of intrahepatic cholangiocarcinoma via PI3K/AKT pathway.

    PubMed

    Xie, Kun; Nian, Jianze; Zhu, Xingyang; Geng, Xiaoping; Liu, Fubao

    2015-01-01

    Increasing evidences have indicated the role of garlicin in inhibiting the progression of various tumors including glioma, pulmonary carcinoma and pancreatic carcinoma, via mediating cell apoptosis or cell cycle. The regulatory effect and related molecular mechanism of garlicin in intrahepatic cholangiocarcinoma, however, remained unknown. This study thus aimed to investigate this scientific issue. HCCC-9810 cell line was treated with serially diluted garlicin, followed by cell proliferation assay using MTT approach. Transwell migration and invasion assays were further employed the regulatory effect of garlicin. The expression level of p-AKT and AKT proteins in tumor cells was quantified by Western blot. The growth of tumor cells was significantly inhibited by high concentration of garlicin (> 1.5 μM). Lower concentration of garlicin showed dose-dependent inhibition of tumor cell invasion and migration. After using specific agonist IGF-1 (50 ng/mL) of PI3K/AKT signaling pathway, such facilitating effects of garlicin were depressed (P < 0.05). Western blotting showed significantly decreased phosphorylation level of AKT after treated with gradient concentrations of garlicin, while leaving the total AKT protein level unchanged. Garlicin may inhibit the invasion and migration of intrahepatic cholangiocarcinoma cells via inhibiting PI3K/AKT signaling pathway.

  5. Modulatory role of garlicin in migration and invasion of intrahepatic cholangiocarcinoma via PI3K/AKT pathway

    PubMed Central

    Xie, Kun; Nian, Jianze; Zhu, Xingyang; Geng, Xiaoping; Liu, Fubao

    2015-01-01

    Increasing evidences have indicated the role of garlicin in inhibiting the progression of various tumors including glioma, pulmonary carcinoma and pancreatic carcinoma, via mediating cell apoptosis or cell cycle. The regulatory effect and related molecular mechanism of garlicin in intrahepatic cholangiocarcinoma, however, remained unknown. This study thus aimed to investigate this scientific issue. HCCC-9810 cell line was treated with serially diluted garlicin, followed by cell proliferation assay using MTT approach. Transwell migration and invasion assays were further employed the regulatory effect of garlicin. The expression level of p-AKT and AKT proteins in tumor cells was quantified by Western blot. The growth of tumor cells was significantly inhibited by high concentration of garlicin (> 1.5 μM). Lower concentration of garlicin showed dose-dependent inhibition of tumor cell invasion and migration. After using specific agonist IGF-1 (50 ng/mL) of PI3K/AKT signaling pathway, such facilitating effects of garlicin were depressed (P < 0.05). Western blotting showed significantly decreased phosphorylation level of AKT after treated with gradient concentrations of garlicin, while leaving the total AKT protein level unchanged. Garlicin may inhibit the invasion and migration of intrahepatic cholangiocarcinoma cells via inhibiting PI3K/AKT signaling pathway. PMID:26823715

  6. Imaging spectrum of cholangiocarcinoma: role in diagnosis, staging, and posttreatment evaluation.

    PubMed

    Mar, Winnie A; Shon, Andrew M; Lu, Yang; Yu, Jonathan H; Berggruen, Senta M; Guzman, Grace; Ray, Charles E; Miller, Frank

    2016-03-01

    Cholangiocarcinoma, a tumor of biliary epithelium, is increasing in incidence. The imaging appearance, behavior, and treatment of cholangiocarcinoma differ according to its location and morphology. Cholangiocarcinoma is usually classified as intrahepatic, perihilar, or distal. The three morphologies are mass-forming, periductal sclerosing, and intraductal growing. As surgical resection is the only cure, prompt diagnosis and accurate staging is crucial. In staging, vascular involvement, longitudinal spread, and lymphadenopathy are important to assess. The role of liver transplantation for unresectable peripheral cholangiocarcinoma will be discussed. Locoregional therapy can extend survival for those with unresectable intrahepatic tumors. The main risk factors predisposing to cholangiocarcinoma are parasitic infections, primary sclerosing cholangitis, choledochal cysts, and viral hepatitis. Several inflammatory conditions can mimic cholangiocarcinoma, including IgG4 disease, sclerosing cholangitis, Mirizzi's syndrome, and recurrent pyogenic cholangitis. The role of PET in diagnosis and staging will also be discussed. Radiologists play a crucial role in diagnosis, staging, and treatment of this disease.

  7. Protein kinase C phosphorylation disrupts Na+/H+ exchanger regulatory factor 1 autoinhibition and promotes cystic fibrosis transmembrane conductance regulator macromolecular assembly.

    PubMed

    Li, Jianquan; Poulikakos, Poulikos I; Dai, Zhongping; Testa, Joseph R; Callaway, David J E; Bu, Zimei

    2007-09-14

    An emerging theme in cell signaling is that membrane-bound channels and receptors are organized into supramolecular signaling complexes for optimum function and cross-talk. In this study, we determined how protein kinase C (PKC) phosphorylation influences the scaffolding protein Na(+)/H(+) exchanger regulatory factor 1 (NHERF) to assemble protein complexes of cystic fibrosis transmembrane conductance regulator (CFTR), a chloride ion channel that controls fluid and electrolyte transport across cell membranes. NHERF directs polarized expression of receptors and ion transport proteins in epithelial cells, as well as organizes the homo- and hetero-association of these cell surface proteins. NHERF contains two modular PDZ domains that are modular protein-protein interaction motifs, and a C-terminal domain. Previous studies have shown that NHERF is a phosphoprotein, but how phosphorylation affects NHERF to assemble macromolecular complexes is unknown. We show that PKC phosphorylates two amino acid residues Ser-339 and Ser-340 in the C-terminal domain of NHERF, but a serine 162 of PDZ2 is specifically protected from being phosphorylated by the intact C-terminal domain. PKC phosphorylation-mimicking mutant S339D/S340D of NHERF has increased affinity and stoichiometry when binding to C-CFTR. Moreover, solution small angle x-ray scattering indicates that the PDZ2 and C-terminal domains contact each other in NHERF, but such intramolecular domain-domain interactions are released in the PKC phosphorylation-mimicking mutant indicating that PKC phosphorylation disrupts the autoinhibition interactions in NHERF. The results demonstrate that the C-terminal domain of NHERF functions as an intramolecular switch that regulates the binding capability of PDZ2, and thus controls the stoichiometry of NHERF to assemble protein complexes.

  8. DYRK2 and GSK-3 phosphorylate and promote the timely degradation of OMA-1, a key regulator of the oocyte-to-embryo transition in C. elegans.

    PubMed

    Nishi, Yuichi; Lin, Rueyling

    2005-12-01

    Oocyte maturation and fertilization initiates a dynamic and tightly regulated process in which a non-dividing oocyte is transformed into a rapidly dividing embryo. We have shown previously that two C. elegans CCCH zinc finger proteins, OMA-1 and OMA-2, have an essential and redundant function in oocyte maturation. Both OMA-1 and OMA-2 are expressed only in oocytes and 1-cell embryos, and need to be degraded rapidly after the first mitotic division for embryogenesis to proceed normally. We report here a distinct redundant function for OMA-1 and OMA-2 in the 1-cell embryo. Depletion of both oma-1 and oma-2 in embryos leads to embryonic lethality. We also show that OMA-1 protein is directly phosphorylated at T239 by the DYRK kinase MBK-2, and that phosphorylation at T239 is required both for OMA-1 function in the 1-cell embryo and its degradation after the first mitosis. OMA-1 phosphorylated at T239 is only detected within a short developmental window of 1-cell embryos, beginning soon after the proposed activation of MBK-2. Phosphorylation at T239 facilitates subsequent phosphorylation of OMA-1 by another kinase, GSK-3, at T339 in vitro. Phosphorylation at both T239 and T339 are essential for correctly-timed OMA-1 degradation in vivo. We propose that a series of precisely-timed phosphorylation events regulates both the activity and the timing of degradation for OMA proteins, thereby allowing restricted and distinct functions of OMA-1 and OMA-2 in the maturing oocyte and 1-cell embryo, ensuring a normal oocyte-to-embryo transition in C. elegans.

  9. Long-term survival after intraluminal brachytherapy for inoperable hilar cholangiocarcinoma: A case report

    PubMed Central

    Chan, Siu-Yin; Poon, Ronnie T.; Ng, Kelvin K.; Liu, Chi-Leung; Chan, Raymond T.; Fan, Sheung-Tat

    2005-01-01

    Surgical resection with a tumor-free margin is the only curative treatment for hilar cholangiocarcinoma (Klatskin tumor). However, over half of the patients present late with unresectable tumors. Radiotherapy using external beam irradiation or intraluminal brachytherapy (ILBT) has been used to treat unresectable hilar cholangiocarcinoma with satisfactory outcome. We reported a patient with unresectable hilar cholangiocarcinoma surviving more than 6 years after combined external beam irradiation and ILBT. PMID:15918211

  10. Metabolic-Stress-Induced Rearrangement of the 14-3-3ζ Interactome Promotes Autophagy via a ULK1- and AMPK-Regulated 14-3-3ζ Interaction with Phosphorylated Atg9

    PubMed Central

    Weerasekara, Vajira K.; Panek, David J.; Broadbent, David G.; Mortenson, Jeffrey B.; Mathis, Andrew D.; Logan, Gideon N.; Prince, John T.; Thomson, David M.; Thompson, J. Will

    2014-01-01

    14-3-3ζ promotes cell survival via dynamic interactions with a vast network of binding partners, many of which are involved in stress regulation. We show here that hypoxia (low glucose and oxygen) triggers a rearrangement of the 14-3-3ζ interactome to favor an interaction with the core autophagy regulator Atg9A. Our data suggest that the localization of mammalian Atg9A to autophagosomes requires phosphorylation on the C terminus of Atg9A at S761, which creates a 14-3-3ζ docking site. Under basal conditions, this phosphorylation is maintained at a low level and is dependent on both ULK1 and AMPK. However, upon induction of hypoxic stress, activated AMPK bypasses the requirement for ULK1 and mediates S761 phosphorylation directly, resulting in an increase in 14-3-3ζ interactions, recruitment of Atg9A to LC3-positive autophagosomes, and enhanced autophagosome production. These data suggest a novel mechanism whereby the level of autophagy induction can be modulated by AMPK/ULK1-mediated phosphorylation of mammalian Atg9A. PMID:25266655

  11. Transarterial Chemoembolization (TACE) for Inoperable Intrahepatic Cholangiocarcinoma

    SciTech Connect

    Herber, S. Otto, G.; Schneider, J.; Manzl, N.; Kummer, I.; Kanzler, S.; Schuchmann, A.; Thies, J.; Dueber, C.; Pitton, M.

    2007-11-15

    The aim of this retrospective study was to determine the safety and efficacy of chemoembolization (TACE) as palliative treatment for patients with unresectable intrahepatic cholangiocarcinoma (CCA) and to compare the results with those in the literature. Fifteen patients with histology-proven CCA (5 men, 10 women) had received palliative treatment with TACE over a 6-year period. The treatment protocol comprised repeated TACE at a minimum of 8-week intervals. TACE was performed with a mixture of 10 ml Lipiodol and 10 mg mitomycin C injected into the tumor-supplying vessels. Follow-up investigations after 8-10 weeks comprised contrast-enhanced multislice spiral CT and laboratory control. Statistical evaluation included survival analysis using the Kaplan-Meier method. During the investigation period 58 TACEs (3.9 {+-} 3.8; 1-15) were performed in 15 patients. Mean tumor size was 10.8 {+-} 4.6 cm (range, 2.0-18.0 cm). Unifocal tumor disease was diagnosed in eight patients, and multifocal disease in seven. Mean survival was 21.1 months (95% CI, 9.4-32.5 months). At the end of the investigation period 3 patients are still alive, and 12 patients have died. The 1-, 2-, and 3-year survival rate was 51.3%, 27.5%, and 27.5% respectively. According to RECIST criteria interim best response to therapy was stable disease in 9 of 15 patients, a partial response in 1 of 15 patients, and tumor progression in 4 of 15 patients. No deaths and no acute liver failure occurred under TACE therapy. Major complications were observed in two patients, comprising anaphylactic shock owing to contrast medium administration in one and gastric ulceration due to lipiodol displacement in the second patient. These results demonstrate that TACE is a safe procedure with a moderate number of complications for patients suffering from inoperable CCA. According to recently published data on i.v. chemotherapy we suggest that TACE might be able to prolong survival in selected patients who would succumb under

  12. MicroRNA-922 promotes tau phosphorylation by downregulating ubiquitin carboxy-terminal hydrolase L1 (UCHL1) expression in the pathogenesis of Alzheimer's disease.

    PubMed

    Zhao, Z-B; Wu, L; Xiong, R; Wang, L-L; Zhang, B; Wang, C; Li, H; Liang, L; Chen, S-D

    2014-09-05

    Decreased levels of soluble ubiquitin carboxy-terminal hydrolase L1 (UCHL1) have been reported in the brains of sporadic Alzheimer's disease (AD) patients, and the introduction of UCHL1 rescued the synaptic and cognitive function of AD model mice. Obviously, a reduction in the levels of UCHL1 may play a role in the pathogenesis of AD. However, the mechanisms underlying the regulation of UCHL1 levels in AD have not been fully elucidated. MicroRNAs (miRs) have been shown to participate in the process of AD. In our study, we discovered that microRNA-922 decreased the levels of UCHL1. Neurofibrillary tangles (NFTs) mainly consisting of the hyperphosphorylated microtubule-associated protein tau are the defining pathological features of AD. In the present study, we found the levels of UCHL1 affected the levels of phosphorylated tau: the phosphorylated tau levels increased after knockdown of UCHL1 expression, and the phosphorylated tau levels decreased when UCHL1 was overexpressed. Furthermore, overexpression of microRNA-922 increased the phosphorylated tau levels. In conclusion, miR-922 increasing the levels of phosphorylated tau by regulating UCHL1 levels contributed to the pathogenesis of AD. Our study partly explained one of the mechanisms underlying the downregulation of UCHL1 levels in AD patients and could enrich the content of tau pathology in the pathogenesis of AD.

  13. PKM2 Thr454 phosphorylation increases its nuclear translocation and promotes xenograft tumor growth in A549 human lung cancer cells

    SciTech Connect

    Yu, Zhenhai; Huang, Liangqian; Qiao, Pengyun; Jiang, Aifang; Wang, Li; Yang, Tingting; Tang, Shengjian; Zhang, Wei; Ren, Chune

    2016-05-13

    Pyruvate kinase M2 (PKM2) is a key enzyme of glycolysis which is highly expressed in many tumor cells, and plays an important role in the Warburg effect. In previous study, we found PIM2 phosphorylates PKM2 at Thr454 residue (Yu, etl 2013). However, the functions of PKM2 Thr454 modification in cancer cells still remain unclear. Here we find PKM2 translocates into the nucleus after Thr454 phosphorylation. Replacement of wild type PKM2 with a mutant (T454A) enhances mitochondrial respiration, decreases pentose phosphate pathway, and enhances chemosensitivity in A549 cells. In addition, the mutant (T454A) PKM2 reduces xenograft tumor growth in nude mice. These findings demonstrate that PKM2 T454 phosphorylation is a potential therapeutic target in lung cancer.

  14. Tubulin polymerization promoting protein 1 (Tppp1) phosphorylation by Rho-associated coiled-coil kinase (rock) and cyclin-dependent kinase 1 (Cdk1) inhibits microtubule dynamics to increase cell proliferation.

    PubMed

    Schofield, Alice V; Gamell, Cristina; Suryadinata, Randy; Sarcevic, Boris; Bernard, Ora

    2013-03-15

    Tubulin polymerization promoting protein 1 (Tppp1) regulates microtubule (MT) dynamics via promoting MT polymerization and inhibiting histone deacetylase 6 (Hdac6) activity to increase MT acetylation. Our results reveal that as a consequence, Tppp1 inhibits cell proliferation by delaying the G1/S-phase and the mitosis to G1-phase transitions. We show that phosphorylation of Tppp1 by Rho-associated coiled-coil kinase (Rock) prevents its Hdac6 inhibitory activity to enable cells to enter S-phase. Whereas, our analysis of the role of Tppp1 during mitosis revealed that inhibition of its MT polymerizing and Hdac6 regulatory activities were necessary for cells to re-enter the G1-phase. During this investigation, we also discovered that Tppp1 is a novel Cyclin B/Cdk1 (cyclin-dependent kinase) substrate and that Cdk phosphorylation of Tppp1 inhibits its MT polymerizing activity. Overall, our results show that dual Rock and Cdk phosphorylation of Tppp1 inhibits its regulation of the cell cycle to increase cell proliferation.

  15. [Control of Opisthorchis viverrini infection for cholangiocarcinoma prevention].

    PubMed

    Buisson, Y

    2017-02-01

    The International Agency for Research on Cancer (IARC) has classified two liver flukes as carcinogenic to humans (Group 1): Opisthorchis viverrini in 1994 and Clonorchis sinensis in 2009. This review is focused on O. viverrini, the most studied of these two trematodes, which infects nearly 10 million people in Southeast Asia. The life cycle involves two intermediate hosts living in fresh water: a snail of the genus Bithynia and a ciprinid fish. The definitive hosts (human, cat, dog) become infected by ingesting raw fish containing metacercariae, the infective stage of the parasite. Adult flukes attach to the epithelium of the bile ducts where they feed for as long as 10 to 30 years, resulting in chronic inflammation, epithelial hyperplasia, periductal fibrosis and formation of granuloma. For a long asymptomatic, the distomatosis is revealed by a chronic cholangitis when the parasite load becomes high. Complications can occur with time: gallstones, cholangitis, liver abscess, pancreatitis and, after a few decades, cholangiocarcinoma (CCA). The epidemiological correlation between the prevalence of O. viverrini infection and the incidence of CCA has been demonstrated in the northeast of Thailand. Specifically, the Khon Kaen province has the highest incidence rate in the world. The CCA can develop asymptomatically for a long time, especially in intrahepatic locations. It is often discovered at a late stage, unresectable. Its prognosis is dreadful with a survival rate less than 5% at 5 years. The phenomenon of carcinogenesis induced by O. viverrini is multifactorial. It has been specially studied using experimental infection on the Syrian golden hamster. Three intricated mechanisms are involved: (i) the direct damage caused by adult worms on the bile duct epithelium, (ii) the immunopathologic processes related to chronic inflammation (oxidative stress) and (iii) the mitogenic and anti-apoptotic effects of the proteins secreted by the parasite. Exogenous cofactors are

  16. c-Jun N-terminal kinase 1 promotes transforming growth factor-β1-induced epithelial-to-mesenchymal transition via control of linker phosphorylation and transcriptional activity of Smad3.

    PubMed

    Velden, Jos L J van der; Alcorn, John F; Guala, Amy S; Badura, Elsbeth C H L; Janssen-Heininger, Yvonne M W

    2011-04-01

    Transforming growth factor (TGF)-β1 is a key mediator of lung remodeling and fibrosis. Epithelial cells are both a source of and can respond to TGF-β1 with epithelial-to-mesenchymal transition (EMT). We recently determined that TGF-β1-induced EMT in lung epithelial cells requires the presence of c-Jun N-terminal kinase (JNK) 1. Because TGF-β1 signals via Smad complexes, the goal of the present study was to determine the impact of JNK1 on phosphorylation of Smad3 and Smad3-dependent transcriptional responses in lung epithelial cells. Evaluation of JNK1-deficient lung epithelial cells demonstrated that TGF-β1-induced terminal phosphorylation of Smad3 was similar, whereas phosphorylation of mitogen-activated protein kinase sites in the linker regions of Smad3 was diminished, in JNK1-deficient cells compared with wild-type cells. In comparison to wild-type Smad3, expression of a mutant Smad3 in which linker mitogen-activated protein kinase sites were ablated caused a marked attenuation in JNK1 or TGF-β1-induced Smad-binding element transcriptional activity, and expression of plasminogen activator inhibitor-1, fibronectin-1, high-mobility group A2, CArG box-binding factor-A, and fibroblast-specific protein-1, genes critical in the process of EMT. JNK1 enhanced the interaction between Smad3 and Smad4, which depended on linker phosphorylation of Smad3. Conversely, Smad3 with phosphomimetic mutations in the linker domain further enhanced EMT-related genes and proteins, even in the absence of JNK1. Finally, we demonstrated a TGF-β1-induced interaction between Smad3 and JNK1. Collectively, these results demonstrate that Smad3 phosphorylation in the linker region and Smad transcriptional activity are directly or indirectly controlled by JNK1, and provide a putative mechanism whereby JNK1 promotes TGF-β1-induced EMT.

  17. Ras-Induced and Extracellular Signal-Regulated Kinase 1 and 2 Phosphorylation-Dependent Isomerization of Protein Tyrosine Phosphatase (PTP)-PEST by PIN1 Promotes FAK Dephosphorylation by PTP-PEST ▿

    PubMed Central

    Zheng, Yanhua; Yang, Weiwei; Xia, Yan; Hawke, David; Liu, David X.; Lu, Zhimin

    2011-01-01

    Protein tyrosine phosphatase (PTP)-PEST is a critical regulator of cell adhesion and migration. However, the mechanism by which PTP-PEST is regulated in response to oncogenic signaling to dephosphorylate its substrates remains unclear. Here, we demonstrate that activated Ras induces extracellular signal-regulated kinase 1 and 2-dependent phosphorylation of PTP-PEST at S571, which recruits PIN1 to bind to PTP-PEST. Isomerization of the phosphorylated PTP-PEST by PIN1 increases the interaction between PTP-PEST and FAK, which leads to the dephosphorylation of FAK Y397 and the promotion of migration, invasion, and metastasis of v-H-Ras-transformed cells. These findings uncover an important mechanism for the regulation of PTP-PEST in activated Ras-induced tumor progression. PMID:21876001

  18. Ras-induced and extracellular signal-regulated kinase 1 and 2 phosphorylation-dependent isomerization of protein tyrosine phosphatase (PTP)-PEST by PIN1 promotes FAK dephosphorylation by PTP-PEST.

    PubMed

    Zheng, Yanhua; Yang, Weiwei; Xia, Yan; Hawke, David; Liu, David X; Lu, Zhimin

    2011-11-01

    Protein tyrosine phosphatase (PTP)-PEST is a critical regulator of cell adhesion and migration. However, the mechanism by which PTP-PEST is regulated in response to oncogenic signaling to dephosphorylate its substrates remains unclear. Here, we demonstrate that activated Ras induces extracellular signal-regulated kinase 1 and 2-dependent phosphorylation of PTP-PEST at S571, which recruits PIN1 to bind to PTP-PEST. Isomerization of the phosphorylated PTP-PEST by PIN1 increases the interaction between PTP-PEST and FAK, which leads to the dephosphorylation of FAK Y397 and the promotion of migration, invasion, and metastasis of v-H-Ras-transformed cells. These findings uncover an important mechanism for the regulation of PTP-PEST in activated Ras-induced tumor progression.

  19. TOR and S6K1 promote translation reinitiation of uORF-containing mRNAs via phosphorylation of eIF3h.

    PubMed

    Schepetilnikov, Mikhail; Dimitrova, Maria; Mancera-Martínez, Eder; Geldreich, Angèle; Keller, Mario; Ryabova, Lyubov A

    2013-04-17

    Mammalian target-of-rapamycin (mTOR) triggers S6 kinase (S6K) activation to phosphorylate targets linked to translation in response to energy, nutrients, and hormones. Pathways of TOR activation in plants remain unknown. Here, we uncover the role of the phytohormone auxin in TOR signalling activation and reinitiation after upstream open reading frame (uORF) translation, which in plants is dependent on translation initiation factor eIF3h. We show that auxin triggers TOR activation followed by S6K1 phosphorylation at T449 and efficient loading of uORF-mRNAs onto polysomes in a manner sensitive to the TOR inhibitor Torin-1. Torin-1 mediates recruitment of inactive S6K1 to polysomes, while auxin triggers S6K1 dissociation and recruitment of activated TOR instead. A putative target of TOR/S6K1-eIF3h-is phosphorylated and detected in polysomes in response to auxin. In TOR-deficient plants, polysomes were prebound by inactive S6K1, and loading of uORF-mRNAs and eIF3h was impaired. Transient expression of eIF3h-S178D in plant protoplasts specifically upregulates uORF-mRNA translation. We propose that TOR functions in polysomes to maintain the active S6K1 (and thus eIF3h) phosphorylation status that is critical for translation reinitiation.

  20. TOR and S6K1 promote translation reinitiation of uORF-containing mRNAs via phosphorylation of eIF3h

    PubMed Central

    Schepetilnikov, Mikhail; Dimitrova, Maria; Mancera-Martínez, Eder; Geldreich, Angèle; Keller, Mario; Ryabova, Lyubov A

    2013-01-01

    Mammalian target-of-rapamycin (mTOR) triggers S6 kinase (S6K) activation to phosphorylate targets linked to translation in response to energy, nutrients, and hormones. Pathways of TOR activation in plants remain unknown. Here, we uncover the role of the phytohormone auxin in TOR signalling activation and reinitiation after upstream open reading frame (uORF) translation, which in plants is dependent on translation initiation factor eIF3h. We show that auxin triggers TOR activation followed by S6K1 phosphorylation at T449 and efficient loading of uORF-mRNAs onto polysomes in a manner sensitive to the TOR inhibitor Torin-1. Torin-1 mediates recruitment of inactive S6K1 to polysomes, while auxin triggers S6K1 dissociation and recruitment of activated TOR instead. A putative target of TOR/S6K1—eIF3h—is phosphorylated and detected in polysomes in response to auxin. In TOR-deficient plants, polysomes were prebound by inactive S6K1, and loading of uORF-mRNAs and eIF3h was impaired. Transient expression of eIF3h-S178D in plant protoplasts specifically upregulates uORF-mRNA translation. We propose that TOR functions in polysomes to maintain the active S6K1 (and thus eIF3h) phosphorylation status that is critical for translation reinitiation. PMID:23524850

  1. Hydrogen peroxide inhibits transforming growth factor-β1-induced cell cycle arrest by promoting Smad3 linker phosphorylation through activation of Akt-ERK1/2-linked signaling pathway.

    PubMed

    Choi, Jiyeon; Park, Seong Ji; Jo, Eun Ji; Lee, Hui-Young; Hong, Suntaek; Kim, Seong-Jin; Kim, Byung-Chul

    2013-06-14

    Hydrogen peroxide (H2O2) functions as a second messenger in growth factor receptor-mediated intracellular signaling cascade and is tumorigenic by virtue of its ability to promote cell proliferation; however, the mechanisms underlying the growth stimulatory action of H2O2 are less understood. Here we report an important mechanism for antagonistic effects of H2O2 on growth inhibitory response to transforming growth factor-β1 (TGF-β1). In Mv1Lu and HepG2 cells, pretreatment of H2O2 (0.05-0.2 mM) completely blocked TGF-β1-mediated induction of p15(INK4B) expression and increase of its promoter activity. Interestingly, H2O2 selectively suppressed the transcriptional activation potential of Smad3, not Smad2, in the absence of effects on TGF-β1-induced phosphorylation of the COOH-tail SSXS motif of Smad3 and its nuclear translocation. Mechanism studies showed that H2O2 increases the phosphorylation of Smad3 at the middle linker region in a concentration- and time-dependent manner and this effect is mediated by activation of extracellular signal-activated kinase 1/2 through Akt. Furthermore, expression of a mutant Smad3 in which linker phosphorylation sites were ablated significantly abrogated the inhibitory effects of H2O2 on TGF-β1-induced increase of p15(INK4B)-Luc reporter activity and blockade of cell cycle progression from G1 to S phase. These findings for the first time define H2O2 as a signaling molecule that modulate Smad3 linker phosphorylation and its transcriptional activity, thus providing a potential mechanism whereby H2O2 antagonizes the cytostatic function of TGF-β1.

  2. Hydrogen peroxide inhibits transforming growth factor-β1-induced cell cycle arrest by promoting Smad3 linker phosphorylation through activation of Akt-ERK1/2-linked signaling pathway

    SciTech Connect

    Choi, Jiyeon; Park, Seong Ji; Jo, Eun Ji; Lee, Hui-Young; Hong, Suntaek; Kim, Seong-Jin; Kim, Byung-Chul

    2013-06-14

    Highlights: •H{sub 2}O{sub 2} inhibits TGF-β1-induced cell cycle arrest. •H{sub 2}O{sub 2} induces Smad3 linker phosphorylation through Akt-ERK1/2 pathway. •H{sub 2}O{sub 2}-mediated suppression of TGF-β signal requires Smad3 linker phosphorylation. •This is a first report about interplay between H{sub 2}O{sub 2} and growth inhibition pathway. -- Abstract: Hydrogen peroxide (H{sub 2}O{sub 2}) functions as a second messenger in growth factor receptor-mediated intracellular signaling cascade and is tumorigenic by virtue of its ability to promote cell proliferation; however, the mechanisms underlying the growth stimulatory action of H{sub 2}O{sub 2} are less understood. Here we report an important mechanism for antagonistic effects of H{sub 2}O{sub 2} on growth inhibitory response to transforming growth factor-β1 (TGF-β1). In Mv1Lu and HepG2 cells, pretreatment of H{sub 2}O{sub 2} (0.05–0.2 mM) completely blocked TGF-β1-mediated induction of p15{sup INK4B} expression and increase of its promoter activity. Interestingly, H{sub 2}O{sub 2} selectively suppressed the transcriptional activation potential of Smad3, not Smad2, in the absence of effects on TGF-β1-induced phosphorylation of the COOH-tail SSXS motif of Smad3 and its nuclear translocation. Mechanism studies showed that H{sub 2}O{sub 2} increases the phosphorylation of Smad3 at the middle linker region in a concentration- and time-dependent manner and this effect is mediated by activation of extracellular signal-activated kinase 1/2 through Akt. Furthermore, expression of a mutant Smad3 in which linker phosphorylation sites were ablated significantly abrogated the inhibitory effects of H{sub 2}O{sub 2} on TGF-β1-induced increase of p15{sup INK4B}-Luc reporter activity and blockade of cell cycle progression from G1 to S phase. These findings for the first time define H{sub 2}O{sub 2} as a signaling molecule that modulate Smad3 linker phosphorylation and its transcriptional activity, thus providing

  3. Atypical Ormond's disease associated with bile duct stricture mimicking cholangiocarcinoma.

    PubMed

    Quante, Michael; Appenrodt, Beate; Randerath, Simone; Wolff, Martin; Fischer, Hans-Peter; Sauerbruch, Tilman

    2009-01-01

    A 55-year-old woman with suspected hilar cholangiocarcinoma presented with jaundice and dilated intrahepatic bile ducts owing to high-grade hepatic duct confluence stenosis. The suspected tumour and the entire extrahepatic bile duct system were resected and Roux-en-Y hepaticojejunostomy was performed. Histological investigations showed perihepatic fibrosis but no signs of malignancy. One year later the patient developed bilateral hydronephrosis caused by ureteral obstruction. Since the patient had a gynaecological history of widespread inflammation, she was referred for transabdominal operative ureterolysis combined with hysterectomy and adnexectomy. Histological investigations as well as fluorodeoxyglucose-positron emission tomography (FDG-PET) and computed tomography (CT) findings were compatible with retroperitoneal fibrosis (Ormond's disease). Treatment with tamoxifen was initiated. To the best of our knowledge, only a few cases of intraperitoneal fibroses mimicking cholangiocarcinoma followed by the typical symptoms of retroperitoneal Ormond's disease have been reported.

  4. Common Hepatic Duct Mixed Adenoneuroendocrine Carcinoma Masquerading as Cholangiocarcinoma

    PubMed Central

    Priyanka Akhilesh, Sali; Kamal Sunder, Yadav; Chandralekha, Tampi; Samir, Parikh; Prasad Kashinath, Wagle

    2016-01-01

    Bile duct mixed adenoneuroendocrine carcinoma (MANEC) is a rare entity. It is defined as having mixed elements of both neuroendocrine tumors (NET) and an adenocarcinoma element, the lesser component forming at least 30% of the tumor. It is a subtype of neuroendocrine carcinoma (NEC) showing both gland-forming epithelial tumor cells and neuroendocrine cells. It is generally misdiagnosed as cholangiocarcinoma on imaging studies. The preoperative pathological workup from the endoscopic retrograde cholangiography brush cytology usually misses the NET/NEC component since it often lies deeper in the tumor. However, it is reported that it is the NEC component that defines the prognosis of the tumor; hence, it is vital to identify the NEC component. We present a rare case of common hepatic duct (CHD) MANEC that was preoperatively misdiagnosed as cholangiocarcinoma. PMID:27375908

  5. Intrahepatic cholangiocarcinoma in a captive meerkat (Suricata suricatta).

    PubMed

    Boonsri, Kittikorn; Sritan, Jiraporn; Vechmanus, Thewarach; O'Sullivan, M Gerard; Pringproa, Kidsadagon

    2013-09-01

    A 9-yr-old male meerkat (Suricata suricatta) living in captivity, with a history of anorexia, lethargy, and weight loss, was examined postmortem. Physical examination revealed poor body condition, dehydration, and icteric mucous membranes. Macroscopically, white to yellowish, multinodulated masses were found protruding from the liver. These multinodular masses were also observed in all lobes of the lungs and the mediastinal lymph nodes. Microscopic examination revealed tumors with well-circumscribed, atypical proliferating cuboidal to columnar bile duct epithelial layers arranged in solid sheets and papillary patterns. The neoplastic masses were separated by dense fibrous connective tissues and invaded the normal parenchyma. Periodic acid-Schiff-positive material was occasionally found within the lumen of tubuloacinar structures. Immunohistochemical labeling revealed that neoplastic cells were intensely positive for pan-cytokeratin, but negative for vimentin. Based on the macroscopic and microscopic findings, intrahepatic cholangiocarcinoma was diagnosed. This is the first report describing cholangiocarcinoma in a meerkat.

  6. Spinal cord infarct as a presentation of cholangiocarcinoma with metastases.

    PubMed

    Thar, Yu Yu; Tun, Aung Myint; Huang, Tiangui; Bordia, Sonal; Guevara, Elizabeth

    2015-11-01

    It is well-known that malignancies, particularly pancreatic and brain cancers, often present as venous thromboembolism. However, stroke and angina attributable to arterial occlusion are relatively common presentations as well. We are reporting a patient, with treatment-naïve hepatitis C and multiple liver nodules, was admitted for deep vein thrombosis (DVT) and pulmonary embolism (PE). Subsequently, she developed an ascending paralysis due to spinal cord infarct (SCI) despite adequate anticoagulation. She also had an enlargement of left supraclavicular lymph node, which was confirmed histologically metastatic cholangiocarcinoma. To our best knowledge, this is the first literature report showing the association linking SCI to metastatic cholangiocarcinoma as a consequence of hypercoagulable state of malignancy.

  7. Spinal cord infarct as a presentation of cholangiocarcinoma with metastases

    PubMed Central

    Tun, Aung Myint; Huang, Tiangui; Bordia, Sonal; Guevara, Elizabeth

    2015-01-01

    It is well-known that malignancies, particularly pancreatic and brain cancers, often present as venous thromboembolism. However, stroke and angina attributable to arterial occlusion are relatively common presentations as well. We are reporting a patient, with treatment-naïve hepatitis C and multiple liver nodules, was admitted for deep vein thrombosis (DVT) and pulmonary embolism (PE). Subsequently, she developed an ascending paralysis due to spinal cord infarct (SCI) despite adequate anticoagulation. She also had an enlargement of left supraclavicular lymph node, which was confirmed histologically metastatic cholangiocarcinoma. To our best knowledge, this is the first literature report showing the association linking SCI to metastatic cholangiocarcinoma as a consequence of hypercoagulable state of malignancy. PMID:26697480

  8. Intestinal Cell Kinase (ICK) Promotes Activation of mTOR Complex 1 (mTORC1) through Phosphorylation of Raptor Thr-908*

    PubMed Central

    Wu, Di; Chapman, Jessica R.; Wang, Lifu; Harris, Thurl E.; Shabanowitz, Jeffrey; Hunt, Donald F.; Fu, Zheng

    2012-01-01

    Intestinal cell kinase (ICK), named after its cloning origin, the intestine, is actually a ubiquitously expressed and highly conserved serine/threonine protein kinase. Recently we reported that ICK supports cell proliferation and G1 cell cycle progression. ICK deficiency significantly disrupted the mammalian target of rapamycin (mTOR) complex 1 (mTORC1) signaling events. However, the biological substrates that mediate the downstream signaling effects of ICK in proliferation and the molecular mechanisms by which ICK interacts with mTORC1 are not well defined. Our prior studies also provided biochemical evidence that ICK interacts with the mTOR/Raptor complex in cells and phosphorylates Raptor in vitro. In this report, we investigated whether and how ICK targets Raptor to regulate the activity of mTORC1. Using the ICK substrate consensus sequence [R-P-X-S/T-P/A/T/S], we identified a putative phosphorylation site, RPGT908T, for ICK in human Raptor. By mass spectrometry and a phospho-specific antibody, we showed that Raptor Thr-908 is a novel in vivo phosphorylation site. ICK is able to phosphorylate Raptor Thr-908 both in vitro and in vivo and when Raptor exists in protein complexes with or without mTOR. Although expression of the Raptor T908A mutant did not affect the mTORC1 integrity, it markedly impaired the mTORC1 activation by insulin or by overexpression of the small GTP-binding protein RheB under nutrient starvation. Our findings demonstrate an important role for ICK in modulating the activity of mTORC1 through phosphorylation of Raptor Thr-908 and thus implicate a potential signaling mechanism by which ICK regulates cell proliferation and division. PMID:22356909

  9. Radiotherapy in the Treatment of Patients With Unresectable Extrahepatic Cholangiocarcinoma

    SciTech Connect

    Ghafoori, A. Paiman; Nelson, John W.; Willett, Christopher G.; Chino, Junzo; Tyler, Douglas S.; Hurwitz, Herbert I.; Uronis, Hope E.; Morse, Michael A.; Clough, Robert W.; Czito, Brian G.

    2011-11-01

    Purpose: Extrahepatic cholangiocarcinoma is an uncommon but lethal malignancy. We analyzed the role of definitive chemoradiotherapy for patients with nonmetastatic, locally advanced extrahepatic cholangiocarcinoma treated at a single institution. Methods and Materials: This retrospective analysis included 37 patients who underwent external beam radiation therapy (EBRT) with concurrent chemotherapy and/or brachytherapy (BT) for locally advanced extrahepatic cholangiocarcinoma. Local control (LC) and overall survival (OS) were assessed, and univariate regression analysis was used to evaluate the effects of patient- and treatment-related factors on clinical outcomes. Results: Twenty-three patients received EBRT alone, 8 patients received EBRT plus BT, and 6 patients received BT alone (median follow-up of 14 months). Two patients were alive without evidence of recurrence at the time of analysis. Actuarial OS and LC rates at 1 year were 59% and 90%, respectively, and 22% and 71%, respectively, at 2 years. Two patients lived beyond 5 years without evidence of recurrence. On univariate analysis, EBRT with or without BT improved LC compared to BT alone (97% vs. 56% at 1 year; 75% vs. 56% at 2 years; p = 0.096). Patients who received EBRT alone vs. BT alone also had improved LC (96% vs. 56% at 1 year; 80% vs. 56% at 2 years; p = 0.113). Age, gender, tumor location (proximal vs. distal), histologic differentiation, EBRT dose ({<=} or >50 Gy), EBRT planning method (two-dimensional vs. three-dimensional), and chemotherapy were not associated with patient outcomes. Conclusions: Patients with locally advanced extrahepatic cholangiocarcinoma have poor survival. Long-term survival is rare. The majority of patients treated with EBRT had local control at the time of death, suggesting that symptoms due to the local tumor effect might be effectively controlled with radiation therapy, and EBRT is an important element of treatment. Novel treatment approaches are indicated in the therapy

  10. RADIOTHERAPY IN THE TREATMENT OF PATIENTS WITH UNRESECTABLE EXTRAHEPATIC CHOLANGIOCARCINOMA

    PubMed Central

    Ghafoori, A. Paiman; Nelson, John W.; Willett, Christopher G.; Chino, Junzo; Tyler, Douglas S.; Hurwitz, Herbert I.; Uronis, Hope E.; Morse, Michael A.; Clough, Robert W.; Czito, Brian G.

    2014-01-01

    Purpose Extrahepatic cholangiocarcinoma is an uncommon but lethal malignancy. We analyzed the role of definitive chemoradiotherapy for patients with nonmetastatic, locally advanced extrahepatic cholangiocarcinoma treated at a single institution. Methods and Materials This retrospective analysis included 37 patients who underwent external beam radiation therapy (EBRT) with concurrent chemotherapy and/or brachytherapy (BT) for locally advanced extrahepatic cholangiocarcinoma. Local control (LC) and overall survival (OS) were assessed, and univariate regression analysis was used to evaluate the effects of patient- and treatment-related factors on clinical outcomes. Results Twenty-three patients received EBRT alone, 8 patients received EBRT plus BT, and 6 patients received BT alone (median follow-up of 14 months). Two patients were alive without evidence of recurrence at the time of analysis. Actuarial OS and LC rates at 1 year were 59% and 90%, respectively, and 22% and 71%, respectively, at 2 years. Two patients lived beyond 5 years without evidence of recurrence. On univariate analysis, EBRT with or without BT improved LC compared to BT alone (97% vs. 56% at 1 year; 75% vs. 56% at 2 years; p = 0.096). Patients who received EBRT alone vs. BT alone also had improved LC (96% vs. 56% at 1 year; 80% vs. 56% at 2 years; p = 0.113). Age, gender, tumor location (proximal vs. distal), histologic differentiation, EBRT dose (≤ or >50 Gy), EBRT planning method (two-dimensional vs. three-dimensional), and chemotherapy were not associated with patient outcomes. Conclusions Patients with locally advanced extrahepatic cholangiocarcinoma have poor survival. Long-term survival is rare. The majority of patients treated with EBRT had local control at the time of death, suggesting that symptoms due to the local tumor effect might be effectively controlled with radiation therapy, and EBRT is an important element of treatment. Novel treatment approaches are indicated in the therapy for

  11. Liver carcinogenesis: Rodent models of hepatocarcinoma and cholangiocarcinoma

    PubMed Central

    Minicis, Samuele De; Kisseleva, Tatiana; Francis, Heather; Baroni, Gianluca Svegliati; Benedetti, Antonio; Brenner, David; Alvaro, Domenico; Alpini, Gianfranco; Marzioni, Marco

    2013-01-01

    Hepatocellular carcinoma and cholangiocarcinoma are primary liver cancers, both represent a growing challenge for clinicians due to their increasing morbidity and mortality. In the last few years a number of in vivo models of hepatocellular carcinoma and cholangiocarcinoma have been developed. The study of these models is providing a significant contribution in unveiling the pathophysiology of primary liver malignancies. They are also fundamental tools to evaluate newly designed molecules to be tested as new potential therapeutic agents in a pre-clinical set. Technical aspects of each model are critical steps, and they should always be considered in order to appropriately interpret the findings of a study or its planning. The purpose of this review is to describe the technical and experimental features of the most significant rodent models, highlighting similarities or differences between the corresponding human diseases. The first part is dedicated to the discussion of models of hepatocellular carcinoma, developed using toxic agents, or through dietary or genetic manipulations. In the second we will address models of cholangiocarcinoma developed in rats or mice by toxin administration, genetic manipulation and/or bile duct incannulation or surgery. Xenograft or syngenic models are also proposed. PMID:23177172

  12. Liver transplantation for cholangiocarcinoma: Current status and new insights

    PubMed Central

    Sapisochín, Gonzalo; Fernández de Sevilla, Elena; Echeverri, Juan; Charco, Ramón

    2015-01-01

    Cholangiocarcinoma is a malignant tumor of the biliary system that can be classified into intrahepatic (iCCA), perihiliar (phCCA) and distal. Initial experiences with orthotopic liver transplantation (OLT) for patients with iCCA and phCCA had very poor results and this treatment strategy was abandoned. In the last decade, thanks to a strict selection process and a neoadjuvant chemoradiation protocol, the results of OLT for patients with non-resectable phCCA have been shown to be excellent and this strategy has been extended worldwide in selected transplant centers. Intrahepatic cholangiocarcinoma is a growing disease in most countries and can be diagnosed both in cirrhotic and in non-cirrhotic livers. Even though OLT is contraindicated in most centers, recent investigations analyzing patients that were transplanted with a misdiagnosis of HCC and were found to have an iCCA have shown encouraging results. There is some information suggesting that patients with early stages of the disease could benefit from OLT. In this review we analyze the current state-of-the-art of OLT for cholangiocarcinoma as well as the new insights and future perspectives. PMID:26464755

  13. Clinical features, histology, and histogenesis of combined hepatocellular-cholangiocarcinoma

    PubMed Central

    Gera, Shweta; Ettel, Mark; Acosta-Gonzalez, Gabriel; Xu, Ruliang

    2017-01-01

    Combined hepatocellular-cholangiocarcinoma (CHC) is a rare tumor with poor prognosis, with incidence ranging from 1.0%-4.7% of all primary hepatic tumors. This entity will be soon renamed as hepato-cholangiocarcinoma. The known risk factors for hepatocellular carcinoma (HCC) have been implicated for CHC including viral hepatitis and cirrhosis. It is difficult to diagnose this tumor pre-operatively. The predominant histologic component within the tumor largely determines the predominant radiographic features making it a difficult distinction. Heterogeneous and overlapping imaging features of HCC and cholangiocarcinoma should raise the suspicion for CHC and multiple core biopsies (from different areas of tumor) are recommended before administering treatment. Serum tumor markers CA19-9 and alpha-fetoprotein can aid in the diagnosis, but it remains a challenging diagnosis prior to resection. There is sufficient data to support bipotent hepatic progenitor cells as the cell of origin for CHC. The current World Health Organization classification categorizes two main types of CHC based on histo-morphological features: Classical type and CHC with stem cell features. Liver transplant is one of the available treatment modalities with other management options including transarterial chemoembolization, radiofrequency ablation, and percutaneous ethanol injection. We present a review paper on CHC highlighting the risk factors, origin, histological classification and therapeutic modalities. PMID:28293379

  14. Enhanced TLR4 Expression on Colon Cancer Cells After Chemotherapy Promotes Cell Survival and Epithelial-Mesenchymal Transition Through Phosphorylation of GSK3β.

    PubMed

    Chung, Yoon Hee; Kim, Daejin

    2016-07-01

    Phosphorylation of glycogen synthase kinase 3β (GSK3β) by phosphatidyl-inositide 3-kinase (PI3K)/protein kinase B (AKT) or inhibition of GSK3β with small-molecule inhibitor attenuates cell survival and proliferation and increases apoptosis in most cancer cell lines. In this study, we investigated the role of phosphorylated GSK3β activated by enhanced toll-like receptor 4 (TLR4) expression in drug-treated colon cancer cells as a model of post-chemotherapy cancer cells. The effect of TLR4 stimulation on metastasis and apoptosis in drug-exposed colon cancer cells was determined by real-time polymerase chain reaction (PCR) and immunoblotting. Despite the induction of apoptosis after treatment with oxaliplatin and 5-fluorouracil, lipopolysaccharide (LPS) stimulation via increased TLR4 in drug-treated cancer cells effectively inhibited apoptosis through up-regulation of expression of anti-apoptosis-related B-cell lymphoma 2 (BCL2) family proteins [X-linked inhibitor of apoptosis protein (XIAP), BCL2, and survivin] and drug-resistance proteins [multidrug-resistance protein 1 (MDR1), multidrug resistance-associated protein (MRP)1/2/3]. LPS-mediated signaling in drug-treated cancer cells elevated the expression of phosphorylated GSK3β, extracellular signal-regulated kinase (ERK), and the p65 subunit of nuclear factor kappa-light-chain-enhancer of activated B-cells (NF-κB). Pharmacological inhibition of GSK3β (using SB216763) reduced phosphorylation of GSK3β, re-activated caspase-dependent apoptosis, and blocked the expression of cancer stem cell markers and invasive characteristics in LPS-stimulated drug-treated cells. In addition, the ERK-specific inhibitor, PD98059, triggered the apoptosis of TLR4-activated drug-exposed colon cancer cells, whereas there was no effect on the expression of epithelial-mesenchymal transition markers or GSK3β phosphorylation. These results suggest that TLR4-induced GSK3β and ERK phosphorylation independently controls cancer cell

  15. Opposing actions of endocannabinoids on cholangiocarcinoma growth is via the differential activation of Notch signaling

    SciTech Connect

    Frampton, Gabriel; Coufal, Monique; Li, Huang; Ramirez, Jonathan; DeMorrow, Sharon

    2010-05-15

    The endocannabinoids anandamide (AEA) and 2-arachidonylglycerol (2-AG) have opposing effects on cholangiocarcinoma growth. Implicated in cancer, Notch signaling requires the {gamma}-secretase complex for activation. The aims of this study were to determine if the opposing effects of endocannabinoids depend on the differential activation of the Notch receptors and to demonstrate that the differential activation of these receptors are due to presenilin 1 containing- and presenilin 2 containing-{gamma}-secretase complexes. Mz-ChA-1 cells were treated with AEA or 2-AG. Notch receptor expression, activation, and nuclear translocation were determined. Specific roles for Notch 1 and 2 on cannabinoid-induced effects were determined by transient transfection of Notch 1 or 2 shRNA vectors before stimulation with AEA or 2-AG. Expression of presenilin 1 and 2 was determined after AEA or 2-AG treatment, and the involvement of presenilin 1 and 2 in the cannabinoid-induced effects was demonstrated in cell lines with low presenilin 1 or 2 expression. Antiproliferative effects of AEA required increased Notch 1 mRNA, activation, and nuclear translocation, whereas the growth-promoting effects induced by 2-AG required increased Notch 2 mRNA expression, activation, and nuclear translocation. AEA increased presenilin 1 expression and recruitment into the {gamma}-secretase complex, whereas 2-AG increased expression and recruitment of presenilin 2. The development of novel therapeutic strategies aimed at modulating the endocannabinoid system or mimicking the mode of action of AEA on Notch signaling pathways would prove beneficial for cholangiocarcinoma management.

  16. IL-33 Facilitates Oncogene Induced Cholangiocarcinoma in Mice by an IL-6 Sensitive Mechanism

    PubMed Central

    Yamada, Daisaku; Rizvi, Sumera; Razumilava, Nataliya; Bronk, Steven F.; Davila, Jaime I.; Champion, Mia D.; Borad, Mitesh J.; Bezerra, Jorge A.; Chen, Xin; Gores, Gregory J.

    2015-01-01

    Cholangiocarcinoma (CCA) is a lethal hepatobiliary neoplasm originating from the biliary apparatus. In humans, CCA risk factors include hepatobiliary inflammation and fibrosis. The recently identified IL-1 family member, IL-33, has been shown to be a biliary mitogen which also promotes liver inflammation and fibrosis. Our aim was to generate a mouse model of CCA mimicking the human disease. Ectopic oncogene expression in the biliary tract was accomplished by the Sleeping Beauty transposon transfection system with transduction of constitutively active AKT (myr-AKT) and Yes-associated protein (YAP). Intrabiliary instillation of the transposon-transposase complex was coupled with lobar bile duct ligation in CL57BL/6 mice, followed by administration of IL-33 for three consecutive days. Tumors developed in 72% of the male mice receiving both oncogenes plus IL-33 by 10 weeks, but in only 20% of the male mice transduced with the oncogenes alone. Tumors expressed SOX9 and pancytokeratin (PanCK) [features of cholangiocarcinoma] but were negative for HepPar1 [a marker of hepatocellular carcinoma (HCC)]. RNA profiling revealed substantive overlap with human CCA specimens. Not only did IL-33 induce IL-6 expression by human cholangiocytes, but IL-33 likely facilitated tumor development in vivo by an IL-6 sensitive process, as tumor development was significantly attenuated in Il-6 -/- male animals. Furthermore, tumor formation occurred at a similar rate when IL-6 was substituted for IL-33 in this model. In conclusion, the transposase-mediated transduction of constitutively active AKT and YAP in the biliary epithelium coupled with lobar obstruction and IL-33 administration results in the development of CCA with morphological and biochemical features of the human disease. This model highlights the role of inflammatory cytokines in CCA oncogenesis. PMID:25580681

  17. Cdk5 promotes DNA replication stress checkpoint activation through RPA-32 phosphorylation, and impacts on metastasis free survival in breast cancer patients

    PubMed Central

    Chiker, Sara; Pennaneach, Vincent; Loew, Damarys; Dingli, Florent; Biard, Denis; Cordelières, Fabrice P; Gemble, Simon; Vacher, Sophie; Bieche, Ivan; Hall, Janet; Fernet, Marie

    2015-01-01

    Cyclin dependent kinase 5 (Cdk5) is a determinant of PARP inhibitor and ionizing radiation (IR) sensitivity. Here we show that Cdk5-depleted (Cdk5-shRNA) HeLa cells show higher sensitivity to S-phase irradiation, chronic hydroxyurea exposure, and 5-fluorouracil and 6-thioguanine treatment, with hydroxyurea and IR sensitivity also seen in Cdk5-depleted U2OS cells. As Cdk5 is not directly implicated in DNA strand break repair we investigated in detail its proposed role in the intra-S checkpoint activation. While Cdk5-shRNA HeLa cells showed altered basal S-phase dynamics with slower replication velocity and fewer active origins per DNA megabase, checkpoint activation was impaired after a hydroxyurea block. Cdk5 depletion was associated with reduced priming phosphorylations of RPA32 serines 29 and 33 and SMC1-Serine 966 phosphorylation, lower levels of RPA serine 4 and 8 phosphorylation and DNA damage measured using the alkaline Comet assay, gamma-H2AX signal intensity, RPA and Rad51 foci, and sister chromatid exchanges resulting in impaired intra-S checkpoint activation and subsequently higher numbers of chromatin bridges. In vitro kinase assays coupled with mass spectrometry demonstrated that Cdk5 can carry out the RPA32 priming phosphorylations on serines 23, 29, and 33 necessary for this checkpoint activation. In addition we found an association between lower Cdk5 levels and longer metastasis free survival in breast cancer patients and survival in Cdk5-depleted breast tumor cells after treatment with IR and a PARP inhibitor. Taken together, these results show that Cdk5 is necessary for basal replication and replication stress checkpoint activation and highlight clinical opportunities to enhance tumor cell killing. PMID:26237679

  18. Kaempferol inhibits the growth and metastasis of cholangiocarcinoma in vitro and in vivo.

    PubMed

    Qin, Youyou; Cui, Wu; Yang, Xuewei; Tong, Baifeng

    2016-03-01

    Kaempferol is a flavonoid that has been reported to exhibit antitumor activity in various malignant tumors. However, the role of kaempferol on cholangiocarcinoma (CCA) is largely unknown. In this article, we found that kaempferol inhibited proliferation, reduced colony formation ability, and induced apoptosis in HCCC9810 and QBC939 cells in vitro. Results from transwell assay and wound-healing assay demonstrated that kaempferol significantly suppressed the migration and invasion abilities of HCCC9810 and QBC939 cells in vitro. Kaempferol was found to decrease the expression of Bcl-2 and increase the expressions of Bax, Fas, cleaved-caspase 3, cleaved-caspase 8, cleaved-caspase 9, and cleaved-PARP. In addition, kaempferol also downregulated the levels of phosphorylated AKT, TIMP2, and MMP2. In vivo, it was found that the volume of subcutaneous xenograft (0.15 cm(3)) in the kaempferol-treated group was smaller than that (0.6 cm(3)) in the control group. Kaempferol also suppressed the number and volume of metastasis foci in the lung metastasis model, with no marked effects on body weight of mice. Immunohistochemistry assay showed that the number of Ki-67-positive cells was lower in the kaempferol-treated group than that in the control group. We further confirmed that the changes of apoptosis- and invasion-related proteins after kaempferol treatment in vivo were similar to the results in vitro. These data suggest that kaempferol may be a promising candidate agent for the treatment of CCA.

  19. STATs profiling reveals predominantly-activated STAT3 in cholangiocarcinoma genesis and progression.

    PubMed

    Dokduang, Hasaya; Techasen, Anchalee; Namwat, Nisana; Khuntikeo, Narong; Pairojkul, Chawalit; Murakami, Yoshinori; Loilome, Watcharin; Yongvanit, Puangrat

    2014-10-01

    We investigated the aberrant expression of the STAT family in humans and liver fluke (Opisthorchis viverrini, Ov)-induced hamster cholangiocarcinoma (CCA) tissues. The expression and phosphorylation of STAT1, STAT2, STAT3, STAT4, STAT5a, STAT5b and STAT6 in human hamster CCA tissues were immunohistochemistry-profiled. Localizations of STAT5 in macrophages and lipopolysaccharide (LPS)-induced macrophage-conditioned media mediated STAT3 activation in CCA cells were demonstrated. The expressions of STAT 1-4 and 6 were detected in the cytoplasm of hyperplastic bile ducts and tumor cells, whereas STAT5a and STAT5b were observed in macrophages and connective tissues surrounding tumor, respectively. The expressions of STAT3 and STAT5b were significantly observed in tumors with a poorer histological differentiation. STAT3 expression was significantly associated with shorter survival of CCA patients and was predominately activated in CCA cell lines. In the CCA-hamsters, STATs expression was gradually increased along the carcinogenesis, especially at 30 days post-infection in which the inflammatory response was markedly observed, showing the correlation between the inflammation and STATs activation. Moreover, LPS-induced macrophage-conditioned media could mediate STAT3 activation in CCA cells. STAT3 is the major STAT, which plays roles in the inflammation that contributes to CCA carcinogenesis and progression and may serve as a marker for a poor prognosis of CCA. © 2014 Japanese Society of Hepato-Biliary-Pancreatic Surgery.

  20. Ganglioside GM3 promotes HGF-stimulated motility of murine hepatoma cell through enhanced phosphorylation of cMet at specific tyrosine sites and PI3K/Akt-mediated migration signaling.

    PubMed

    Li, Ying; Huang, Xiaohua; Zhong, Weiliang; Zhang, Jianing; Ma, Keli

    2013-10-01

    Ganglioside GM3 plays a well-documented and important role in the regulation of tumor cell proliferation, invasion, and metastasis by modulating tyrosine kinase growth factor receptors. However, the effect of GM3 on the hepatocyte growth factor receptor (HGFR, cMet) has not been fully delineated. In the current study, we investigated how GM3 affects cMet signaling and HGF-stimulated cell motility and migration using three hepatic cancer cell lines of mouse (Hca/A2, Hca/16A3, and Hepa1-6). Decreasing GM3 expression with the use of P4, a specific inhibitor for ganglioside synthesis inhibited the HGF-stimulated phosphorylation of cMet and activity of PI3K/Akt signaling pathway. In contrast, the increased expression of GM3 as a result of adding exogenous GM3 enhanced the HGF-stimulated phosphorylation of cMet and activity of PI3K/Akt signaling pathway. Furthermore, HGF-stimulated cell motility and migration in vitro were inhibited by reduced expression of GM3 and enhanced by increased expression of GM3. All the observations indicate that ganglioside GM3 promotes HGF-stimulated motility of murine hepatoma cell through enhanced phosphorylation of cMet at specific tyrosine sites and PI3K/Akt-mediated migration signaling.

  1. Immunoglobulin G4-mediated sclerosing cholangitis as a risk factor for cholangiocarcinoma: A case report

    PubMed Central

    Koopman, Karin E.; Bloemena, Elisabeth; Kazemier, Geert; Klemt-Kropp, Michael

    2016-01-01

    Immunoglobulin (Ig)G4-mediated disease is a systemic autoimmune disease, which occasionally presents solely as sclerosing cholangitis (SC). IgG4-mediated SC is challenging to diagnose, as it may mimic cholangiocarcinoma radiologically, and carcinoma cells may produce IgG4. The diagnosis of IgG4-mediated disease is based on histological consensus criteria and response to corticosteroids. In addition to the radiological and histological overlap between IgG4-mediated SC and cholangiocarcinoma, IgG4-mediated SC may be considered as a risk factor for the development of cholangiocarcinoma. We herein present the case of a patient in whom cholangiocarcinoma developed in two lesions previously characterized as IgG4-mediated SC, including a suggested mechanism underlying the contribution of IgG4-mediated SC to the development of cholangiocarcinoma. PMID:28105357

  2. Prognostic Significance of Neutrophil to Lymphocyte Ratio in Oncologic Outcomes of Cholangiocarcinoma: A Meta-analysis.

    PubMed

    Tan, De-Wen; Fu, Yan; Su, Qi; Guan, Ming-Jun; Kong, Po; Wang, Sheng-Qiang; Wang, He-Ling

    2016-10-03

    Increasing evidence indicates that the neutrophil to lymphocyte ratio (NLR) is a useful biomarker of long-term outcomes in patients with cholangiocarcinoma. However, the prognostic role of NLR in patients with cholangiocarcinoma remains unclear. Thus, the current meta-analysis was undertaken to clarify the correlation between NLR and overall survival (OS) in cholangiocarcinoma, and a comprehensive literature research was conducted to understand the association of NLR and prognosis of cholangiocarcinoma. The hazard ratio (HR) with 95% confidence interval (CI) was used to assess OS. The synthesized HR of 1.449 (95% CI: 1.296-1.619, P < 0.001) indicated that a high NLR had an unfavourable effect on OS. Overall, this meta-analysis suggested that elevated preoperative NLR is associated with poorer rates of survival in cholangiocarcinoma patients.

  3. Phosphorylation of tau is regulated by PKN.

    PubMed

    Taniguchi, T; Kawamata, T; Mukai, H; Hasegawa, H; Isagawa, T; Yasuda, M; Hashimoto, T; Terashima, A; Nakai, M; Mori, H; Ono, Y; Tanaka, C

    2001-03-30

    For the phosphorylation state of microtubule-associated protein, tau plays a pivotal role in regulating microtubule networks in neurons. Tau promotes the assembly and stabilization of microtubules. The potential for tau to bind to microtubules is down-regulated after local phosphorylation. When we investigated the effects of PKN activation on tau phosphorylation, we found that PKN triggers disruption of the microtubule array both in vitro and in vivo and predominantly phosphorylates tau in microtubule binding domains (MBDs). PKN has a catalytic domain highly homologous to protein kinase C (PKC), a kinase that phosphorylates Ser-313 (= Ser-324, the number used in this study) in MBDs. Thus, we identified the phosphorylation sites of PKN and PKC subtypes (PKC-alpha, -betaI, -betaII, -gamma, -delta, -epsilon, -zeta, and -lambda) in MBDs. PKN phosphorylates Ser-258, Ser-320, and Ser-352, although all PKC subtypes phosphorylate Ser-258, Ser-293, Ser-324, and Ser-352. There is a PKN-specific phosphorylation site, Ser-320, in MBDs. HIA3, a novel phosphorylation-dependent antibody recognizing phosphorylated tau at Ser-320, showed immunoreactivity in Chinese hamster ovary cells expressing tau and the active form of PKN, but not in Chinese hamster ovary cells expressing tau and the inactive form of PKN. The immunoreactivity for phosphorylated tau at Ser-320 increased in the presence of a phosphatase inhibitor, FK506 treatment, which means that calcineurin (protein phosphatase 2B) may be involved in dephosphorylating tau at Ser-320 site. We also noted that PKN reduces the phosphorylation recognized by the phosphorylation-dependent antibodies AT8, AT180, and AT270 in vivo. Thus PKN serves as a regulator of microtubules by specific phosphorylation of tau, which leads to disruption of tubulin assembly.

  4. Intrahepatic cholangiocarcinoma in a transplant liver--selective internal radiation therapy followed by right hemihepatectomy: report of a case.

    PubMed

    Sperling, Jens; Justinger, Christoph; Schuld, Jochen; Ziemann, Christian; Seidel, Roland; Kollmar, Otto

    2014-07-01

    Intra- or extrahepatic cholangiocarcinomas are the second most common primary liver malignancies behind hepatocellular carcinoma. Whereas the incidence for intrahepatic cholangiocarcinoma is rising, the occurrence of extrahepatic cholangiocarcinoma is trending downwards. The treatment of choice for intrahepatic cholangiocarcinoma remains liver resection. However, a case of liver resection after selective internal radiation therapy in order to treat a recurrent intrahepatic cholangiocarcinoma in a transplant liver is unknown in the literature so far. Herein, we present a case of a patient undergoing liver transplantation for Wilson's disease with an accidental finding of an intrahepatic cholangiocarcinoma within the explanted liver. Due to a recurrent intrahepatic cholangiocarcinoma after liver transplantation, a selective internal radiation therapy with yttrium-90 microspheres was performed followed by right hemihepatectomy. Four years later, the patient is tumor-free and in a healthy condition.

  5. Binding of Galectin-3, a β-Galactoside-binding Lectin, to MUC1 Protein Enhances Phosphorylation of Extracellular Signal-regulated Kinase 1/2 (ERK1/2) and Akt, Promoting Tumor Cell Malignancy.

    PubMed

    Mori, Yugo; Akita, Kaoru; Yashiro, Masakazu; Sawada, Tetsuji; Hirakawa, Kosei; Murata, Takeomi; Nakada, Hiroshi

    2015-10-23

    Both mucin 1 (MUC1) and galectin-3 are known to be overexpressed in various malignant tumors and associated with a poor prognosis. It has been extensively reported that MUC1 is involved in potentiation of growth factor-dependent signal transduction. Because some carbohydrate moieties carried on MUC1 change to preferable ones for binding of galectin-3 in cancer cells, we speculated that MUC1-mediated signaling may occur through direct binding of galectin-3. Immunochemical studies showed that the distribution of galectin-3 coincided with that of MUC1 in various human tumor tissues but not in human nonmalignant tissues, and the level of galectin-3 retained on the surface of various cancer cells paralleled that of MUC1. Treatment of MUC1-expressing cells with galectin-3 induced phosphorylation of ERK1/2 and Akt following enhanced phosphorylation of MUC1 C-terminal domain, consistently promoting tumor cell malignancy. It is also noted that this enhanced phosphorylation occurred independently of EGF receptor-mediated signaling in both EGF receptor- and MUC1-expressing cells, and multivalency of galectin-3 was important for initiation of MUC1-mediated signaling. Expectedly, both silencing of endogenous galectin-3 and treatment with galectin-3 antagonists down-regulated cell proliferation of MUC1-expressing cells. These results suggest that the binding of galectin-3 to MUC1 plays a key role in MUC1-mediated signaling. Thus, constitutive activation of MUC1-mediated signaling in an autocrine/paracrine manner caused by ligation of galectin-3 promotes uncontrolled tumor cell malignancy. This signaling may be another MUC1-mediated pathway and function in parallel with a growth factor-dependent MUC1-mediated signaling pathway.

  6. Hypoxia Promotes Synergy between Mitomycin C and Bortezomib through a Coordinated Process of Bcl-xL Phosphorylation and Mitochondrial Translocation of p53

    PubMed Central

    Song, Xinxin; Dilly, Ashok-Kumar; Choudry, Haroon Asif; Bartlett, David L.; Kwon, Yong Tae; Lee, Yong J.

    2015-01-01

    Colorectal peritoneal carcinomatosis (CPC) exhibits severe tumor hypoxia, leading to drug resistance and disease aggressiveness. This study demonstrates that the combination of the chemotherapeutic agent mitomycin C with the proteasome inhibitor bortezomib induced synergistic cytotoxicity and apoptosis, which was even more effective under hypoxia in colorectal cancer cells. The combination of mitomycin C and bortezomib at sub-lethal doses induced activation of c-Jun NH2-terminal kinase and p38 mitogen-activated protein kinase and resulted in Bcl-xL phosphorylation at Serine 62, leading to dissociation of Bcl-xL from pro-apoptotic Bak. Interestingly, the intracellular level of p53 became elevated and p53 translocated to the mitochondria during the combinatorial treatment, in particular under hypoxia. The coordinated action of Bcl-xL phosphorylation and p53 translocation to the mitochondria resulted in conformational activation of Bak oligomerization, facilitating cytochrome c release and apoptosis induction. In addition, the combinatorial treatment with mitomycin C and bortezomib significantly inhibited intraperitoneal tumor growth in LS174T cells and increased apoptosis, especially under hypoxic conditions in vivo. This study provides a preclinical rationale for the use of combination therapies for CPC patients. Implications The combination of a chemotherapy agent and proteasome inhibitor at sub-lethal doses induced synergistic apoptosis, in particular under hypoxia, in vitro and in vivo through coordinated action of Bcl-xL and p53 on Bak activation. PMID:26354682

  7. Retinoic acid promotes expression of germline-specific genes in chicken blastoderm cells by stimulating Smad1/5 phosphorylation in a feeder-free culture system.

    PubMed

    Tang, Xiaochuan; Xu, Shiyong; Zhang, Hongpeng; Chen, Qing; Li, Rongyang; Wu, Wangjun; Yu, Minli; Liu, Honglin

    2017-02-20

    Producing transgenic chickens with chicken blastodermal cells (cBCs) is inefficient due to the extremely low germline transmission capacity of cBCs. As chicken primordial germ cells (PGCs) have been reported as an efficient method for producing transgenic chickens, the inefficiency of cBCs could potentially be resolved by inducing them to differentiate into germ cells. However, whether chemical inducers are able to enhance cBCs germline competence in vitro is unknown and the molecular mechanisms of differentiation of chicken pluripotent cells into germ cells are poorly understood. We cultured cBCs with a monolayer morphology in E8 medium, a xeno- and feeder-free medium. We showed that retinoic acid (RA) treatment increased expression of germ cell-specific genes in cBCs. Using western blot, we determined that RA stimulated Smad1/5 phosphorylation. Moreover, Smad1/5 activation regulates the expression of germ cell-specific genes, as co-treatment with a Smad1/5 phosphorylation inhibitor or activator alters expression of these genes. We also demonstrate that Smad1/5 is required for RA-induced differentiation by RNA interference knockdown. Our results demonstrated that E8 medium is able to maintain cBC growth for weeks and RA treatment induced germ cell differentiation of cBCs through the BMP-Smad1/5 signaling pathway.

  8. Cyclin-dependent kinase 5 contributes to endoplasmic reticulum stress induced podocyte apoptosis via promoting MEKK1 phosphorylation at Ser280 in diabetic nephropathy.

    PubMed

    Zhang, Yue; Gao, Xiang; Chen, Shuanggang; Zhao, Min; Chen, Jing; Liu, Rui; Cheng, Shengyang; Qi, Mengyuan; Wang, Shuo; Liu, Wei

    2017-02-01

    Endoplasmic reticulum (ER) stress has been reported to be associated with podocyte apoptosis in diabetic nephropathy, but the mechanism of ER signaling in podocyte apoptosis hasn't been fully understood. Our previous studies have demonstrated that Cyclin-dependent kinase 5 (Cdk5) was associated with podocyte apoptosis in diabetic nephropathy. The present study was designed to examine whether and how Cdk5 activity plays a role in ER stress induced podocyte apoptosis in diabetic nephropathy. The results showed that along with induction of Cdk5 and apoptosis, GRP78 and its two sensors as well as CHOP and cleaved caspase-12 were induced in high glucose treated podocytes. These responses were attenuated by treated salubrinal. The ER stress inducer, tunicamycin, also up-regulated the kinase activity and protein expression of Cdk5 in podocytes accompanied with the increasing of GRP78. On the other hand, Cdk5 phosphorylates MEKK1 at Ser280 in tunicamycin treated podocytes, and together, they increase the JNK phosphorylation. Moreover, disruption of this pathway can decrease the podocyte apoptosis induced by tunicamycin. Therefore, our study proved that Cdk5 may play an important role in ER stress induced podocyte apoptosis through MEKK1/JNK pathway in diabetic nephropathy.

  9. Cdc25A promotes cell survival by stimulating NF-{kappa}B activity through I{kappa}B-{alpha} phosphorylation and destabilization

    SciTech Connect

    Hong, Hey-Young; Choi, Jiyeon; Cho, Young-Wook; Kim, Byung-Chul

    2012-04-06

    Highlights: Black-Right-Pointing-Pointer We examine the antiapoptotic mechanisms of Cdc25A. Black-Right-Pointing-Pointer Smad7 decreases the phosphorylation of I{kappa}B-alpha at Ser-32. Black-Right-Pointing-Pointer Smad7 positively regulates NF-{kappa}B activity through I{kappa}B-alpha ubiquitination. -- Abstract: Cell division cycle 25A (Cdc25A), a dual specificity protein phosphatase, exhibits anti-apoptotic activity, but the underlying molecular mechanisms are poorly characterized. Here we report that Cdc25A inhibits cisplatin-induced apoptotic cell death by stimulating nuclear factor-kappa B (NF-{kappa}B) activity. In HEK-293 cells, Cdc25A decreased protein level of inhibitor subunit kappa B alpha (I{kappa}-B{alpha}) in association with increased serine 32-phosphorylation, followed by stimulation of transcriptional activity of NF-{kappa}B. Inhibition of NF-{kappa}B activity by chemical inhibitor or overexpression of I{kappa}-B{alpha} in Cdc25A-elevated cancer cells resistant to cisplatin improved their sensitivity to cisplatin-induced apoptosis. Our data show for the first time that Cdc25A has an important physiological role in NF-{kappa}B activity regulation and it may be an important survival mechanism of cancer cells.

  10. Omega-3 Polyunsaturated Fatty Acids Upregulate 15-PGDH Expression in Cholangiocarcinoma Cells by Inhibiting miR-26a/b Expression.

    PubMed

    Yao, Lu; Han, Chang; Song, Kyoungsub; Zhang, Jinqiang; Lim, Kyu; Wu, Tong

    2015-04-01

    Prostaglandin E2 (PGE2) is a proinflammatory lipid mediator that promotes cancer growth. The 15-hydroxyprostaglandin dehydrogenase (15-PGDH) catalyzes oxidation of the 15(S)-hydroxyl group of PGE2, leading to its inactivation. Therefore, 15-PGDH induction may offer a strategy to treat cancers that are driven by PGE2, such as human cholangiocarcinoma. Here, we report that omega-3 polyunsaturated fatty acids (ω-3 PUFA) upregulate 15-PGDH expression by inhibiting miR-26a and miR-26b, thereby contributing to ω-3 PUFA-induced inhibition of human cholangiocarcinoma cell growth. Treatment of human cholangiocarcinoma cells (CCLP1 and TFK-1) with ω-3 PUFA (DHA) or transfection of these cells with the Fat-1 gene (encoding Caenorhabditis elegans desaturase, which converts ω-6 PUFA to ω-3 PUFA) significantly increased 15-PGDH enzymes levels, but with little effect on the activity of the 15-PGDH gene promoter. Mechanistic investigations revealed that this increase in 15-PGDH levels in cells was mediated by a reduction in the expression of miR-26a and miR-26b, which target 15-PGDH mRNA and inhibit 15-PGDH translation. These findings were extended by the demonstration that overexpressing miR-26a or miR-26b decreased 15-PGDH protein levels, reversed ω-3 PUFA-induced accumulation of 15-PGDH protein, and prevented ω-3 PUFA-induced inhibition of cholangiocarcinoma cell growth. We further observed that ω-3 PUFA suppressed miR-26a and miR-26b by inhibiting c-myc, a transcription factor that regulates miR-26a/b. Accordingly, c-myc overexpression enhanced expression of miR-26a/b and ablated the ability of ω-3 PUFA to inhibit cell growth. Taken together, our results reveal a novel mechanism for ω-3 PUFA-induced expression of 15-PGDH in human cholangiocarcinoma and provide a preclinical rationale for the evaluation of ω-3 PUFA in treatment of this malignancy.

  11. Comorbidity negatively influences prognosis in patients with extrahepatic cholangiocarcinoma

    PubMed Central

    Fernández-Ruiz, Mario; Guerra-Vales, Juan-Manuel; Colina-Ruizdelgado, Francisco

    2009-01-01

    AIM: To study the outcome and prognostic factors in a series of patients with extrahepatic cholangiocarcinoma and determine the impact of comorbidity on survival. METHODS: A retrospective analysis of 68 patients with extrahepatic cholangiocarcinoma (perihilar, n = 37; distal, n = 31) seen at a single tertiary-care institution during the period 1999-2003 was performed. Data on presentation, management, and outcome were assessed by chart review. Pathologic confirmation was obtained in 37 cases (54.4%). Comorbidity was evaluated by using the Charlson comorbidity index (CCI). RESULTS: Mean age at diagnosis was 73.4 ± 11.5 years. Jaundice was the most common symptom presented (86.8%). Median CCI score was 1 (range, 0 to 4). Nineteen patients (27.9%) underwent tumor resection. Palliative biliary drainage was performed in 39 patients (57.4%), and 6 patients (8.8%) received only best supportive care. Tumor-free margin status (R0) was achieved in 15 cases (78.9% of resection group). Baseline serum carbohydrate antigen 19-9 (CA 19-9) level was revealed to be an independent predictor of surgical treatment (P = 0.026). Overall median survival was 3.1 ± 0.9 mo, with 1- and 2-year survival rates of 21% and 7%, respectively. In the univariate analysis, tumor resection, CCI score, and serum CA 19-9 levels correlated significantly with outcome. In the multivariate analysis, only resection (HR 0.10; 95% CI, 0.02-0.51, P = 0.005) and a CCI score ≥ 2 (HR 3.36; 95% CI, 1.0-10.9, P = 0.045) were found to independently predict survival. CONCLUSION: Tumor resection and comorbidity emerged as significant prognostic variables in extrahepatic cholangiocarcinoma. Comorbidity evaluation instruments should be applied in the clinical management of such patients. PMID:19908335

  12. Multigene mutational profiling of cholangiocarcinomas identifies actionable molecular subgroups

    PubMed Central

    Mafficini, Andrea; Wood, Laura D.; Corbo, Vincenzo; Melisi, Davide; Malleo, Giuseppe; Vicentini, Caterina; Malpeli, Giorgio; Antonello, Davide; Sperandio, Nicola; Capelli, Paola; Tomezzoli, Anna; Iacono, Calogero; Lawlor, Rita T.; Bassi, Claudio; Hruban, Ralph H.; Guglielmi, Alfredo; Tortora, Giampaolo; de Braud, Filippo; Scarpa, Aldo

    2014-01-01

    One-hundred-fifty-three biliary cancers, including 70 intrahepatic cholangiocarcinomas (ICC), 57 extrahepatic cholangiocarcinomas (ECC) and 26 gallbladder carcinomas (GBC) were assessed for mutations in 56 genes using multigene next-generation sequencing. Expression of EGFR and mTOR pathway genes was investigated by immunohistochemistry. At least one mutated gene was observed in 118/153 (77%) cancers. The genes most frequently involved were KRAS (28%), TP53 (18%), ARID1A (12%), IDH1/2 (9%), PBRM1 (9%), BAP1 (7%), and PIK3CA (7%). IDH1/2 (p=0.0005) and BAP1 (p=0.0097) mutations were characteristic of ICC, while KRAS (p=0.0019) and TP53 (p=0.0019) were more frequent in ECC and GBC. Multivariate analysis identified tumour stage and TP53 mutations as independent predictors of survival. Alterations in chromatin remodeling genes (ARID1A, BAP1, PBRM1, SMARCB1) were seen in 31% of cases. Potentially actionable mutations were seen in 104/153 (68%) cancers: i) KRAS/NRAS/BRAF mutations were found in 34% of cancers; ii) mTOR pathway activation was documented by immunohistochemistry in 51% of cases and by mutations in mTOR pathway genes in 19% of cancers; iii) TGF-ß/Smad signaling was altered in 10.5% cancers; iv) mutations in tyrosine kinase receptors were found in 9% cases. Our study identified molecular subgroups of cholangiocarcinomas that can be explored for specific drug targeting in clinical trials. PMID:24867389

  13. Promotion

    PubMed Central

    Alam, Hasan B.

    2013-01-01

    This article gives an overview of the promotion process in an academic medical center. A description of different promotional tracks, tenure and endowed chairs, and the process of submitting an application is provided. Finally, some practical advice about developing skills and attributes that can help with academic growth and promotion is dispensed. PMID:24436683

  14. Recurrent Cardiac Tamponade: An Unusual Presentation of Intrahepatic Cholangiocarcinoma

    PubMed Central

    Corral, Juan E.; Arosemena, Leopoldo; Garcia-Buitrago, Monica T.; Madrazo, Beatrice; Martin, Paul

    2016-01-01

    A 48-year-old Egyptian woman presented with 8 months of sharp right upper chest pain and weight loss. She was discovered to have an enlarged cardiac silhouette on chest x-ray, and an echocardiogram revealed a large pericardial effusion with diastolic right atrial collapse. Pericardial window was done, and epithelial membrane antigen-positive neoplastic cells were identified in the pericardial fluid. Computed tomography showed a 6-cm hypermetabolic lesion on the liver segment IV, confirmed on biopsy to be a moderately differentiated adenocarcinoma consistent with intrahepatic cholangiocarcinoma. PMID:27144206

  15. Perinatal exposure to lead (Pb) promotes Tau phosphorylation in the rat brain in a GSK-3β and CDK5 dependent manner: Relevance to neurological disorders.

    PubMed

    Gąssowska, Magdalena; Baranowska-Bosiacka, Irena; Moczydłowska, Joanna; Tarnowski, Maciej; Pilutin, Anna; Gutowska, Izabela; Strużyńska, Lidia; Chlubek, Dariusz; Adamczyk, Agata

    2016-03-10

    Hyperphosphorylation of Tau is involved in the pathomechanism of neurological disorders such as Alzheimer's, Parkinson's diseases as well as Autism. Epidemiological data suggest the significance of early life exposure to lead (Pb) in etiology of disorders affecting brain function. However, the precise mechanisms by which Pb exerts neurotoxic effects are not fully elucidated. The purpose of this study was to evaluate the effect of perinatal exposure to low dose of Pb on the Tau pathology in the developing rat brain. Furthermore, the involvement of two major Tau-kinases: glycogen synthase kinase-3 beta (GSK-3β) and cyclin-dependent kinase 5 (CDK5) in Pb-induced Tau modification was evaluated. Pregnant female rats were divided into control and Pb-treated group. The control animals were maintained on drinking water while females from the Pb-treated group received 0.1% lead acetate (PbAc) in drinking water, starting from the first day of gestation until weaning of the offspring. During the feeding of pups, mothers from the Pb-treated group were still receiving PbAc. Pups of both groups were weaned at postnatal day 21 and then until postnatal day 28 received only drinking water. 28-day old pups were sacrificed and Tau mRNA and protein level as well as Tau phosphorylation were analyzed in forebrain cortex (FC), cerebellum (C) and hippocampus (H). Concomitantly, we examined the effect of Pb exposure on GSK-3β and CDK5 activation. Our data revealed that pre- and neonatal exposure to Pb (concentration of Pb in whole blood below 10μg/dL, considered safe for humans) caused significant increase in the phosphorylation of Tau at Ser396 and Ser199/202 with parallel rise in the level of total Tau protein in FC and C. Tau hyperphosphorylation in Pb-treated animals was accompanied by elevated activity of GSK-3β and CDK5. Western blot analysis revealed activation of GSK-3β in FC and C as well as CDK5 in C, via increased phosphorylation of Tyr-216 and calpain-dependent p25

  16. Hypermutation and unique mutational signatures of occupational cholangiocarcinoma in printing workers exposed to haloalkanes

    PubMed Central

    Mimaki, Sachiyo; Totsuka, Yukari; Suzuki, Yutaka; Nakai, Chikako; Goto, Masanori; Kojima, Motohiro; Arakawa, Hirofumi; Takemura, Shigekazu; Tanaka, Shogo; Marubashi, Shigeru; Kinoshita, Masahiko; Matsuda, Tomonari; Shibata, Tatsuhiro; Nakagama, Hitoshi; Ochiai, Atsushi; Kubo, Shoji; Nakamori, Shoji; Esumi, Hiroyasu; Tsuchihara, Katsuya

    2016-01-01

    Cholangiocarcinoma is a relatively rare cancer, but its incidence is increasing worldwide. Although several risk factors have been suggested, the etiology and pathogenesis of the majority of cholangiocarcinomas remain unclear. Recently, a high incidence of early-onset cholangiocarcinoma was reported among the workers of a printing company in Osaka, Japan. These workers underwent high exposure to organic solvents, mainly haloalkanes such as 1,2-dichloropropane (1,2-DCP) and/or dichloromethane. We performed whole-exome analysis on four cases of cholangiocarcinoma among the printing workers. An average of 44.8 somatic mutations was detected per Mb in the genome of the printing workers’ cholangiocarcinoma tissues, approximately 30-fold higher than that found in control common cholangiocarcinoma tissues. Furthermore, C:G-to-T:A transitions with substantial strand bias as well as unique trinucleotide mutational changes of GpCpY to GpTpY and NpCpY to NpTpY or NpApY were predominant in all of the printing workers’ cholangiocarcinoma genomes. These results were consistent with the epidemiological observation that they had been exposed to high concentrations of chemical compounds. Whole-genome analysis of Salmonella typhimurium strain TA100 exposed to 1,2-DCP revealed a partial recapitulation of the mutational signature in the printing workers’ cholangiocarcinoma. Although our results provide mutational signatures unique to occupational cholangiocarcinoma, the underlying mechanisms of the disease should be further investigated by using appropriate model systems and by comparison with genomic data from other cancers. PMID:27267998

  17. Effect of verteporfin-PDT on epithelial growth factor receptor (EGFR) signaling pathway in cholangiocarcinoma cell lines

    NASA Astrophysics Data System (ADS)

    Andreola, Fausto; Cerec, Virginie; Pereira, Stephen P.

    2009-06-01

    EGFR, a member of the ERBB family, plays a pivotal role in carcinogenesis. EGFR overexpression is implicated in DNA repair and synergistic interactions between EGFR-targeting drugs and conventional chemo/radiotherapy have been reported in preclinical studies for different cancers but not cholangiocarcinoma (CCA). To date there are no in vitro data available on the cellular response and effect of either photodynamic therapy (PDT) or EGFR-targeting drugs on CCA. Therefore, we aimed to study the: (i) response to Verteporfin PDT and to EGFR-targeting drugs, as single agents; (ii) effect of PDT on ERBBs expression, phosporylation status and activation of its signaling pathways; (iii) response to combination of PDT and EGFR-targeting agents. We showed that two cholangiocarcinoma cell lines (HuCCT1 and TFK1 cells, intra- and extrahepatic, respectively) differentially respond to verteporfin-PDT treatment and are resistant to EGFR-targeting agents. A constitutive activation of EGFR in both cell lines was also observed, which could partly account for the observed resistance to EGFR-targeting drugs. In addition, verteporfin-PDT induced further phosphorylation of both EGFR and other Receptor Tyrosine Kinases. Mitochondria-independent apoptosis was induced by PDT in both CCA cell lines; in particular, PDT modulated the expression of members of the Inhibitor of Apoptosis (IAP) family of proteins. Interestingly, there was a PDT-induced EGFR nuclear translocation in both cell lines; co-treatment with either an EGFR-inhibitor (Cetuximab) or a nuclear import blocking agent (Wheat Germ Agglutinin) had an additive effect on PDT cell killing, thus implying a role of EGFR in repairing the potential PDT-induced DNA damage.

  18. Upregulation of transferrin receptor-1 induces cholangiocarcinoma progression via induction of labile iron pool.

    PubMed

    Jamnongkan, Wassana; Thanan, Raynoo; Techasen, Anchalee; Namwat, Nisana; Loilome, Watcharin; Intarawichian, Piyapharom; Titapun, Attapol; Yongvanit, Puangrat

    2017-07-01

    Labile iron pool is a cellular source of ions available for Fenton reactions resulting in oxidative stress. Living organisms avoid an excess of free irons by a tight control of iron homeostasis. We investigated the altered expression of iron regulatory proteins and iron discrimination in the development of liver fluke-associated cholangiocarcinoma. Additionally, the levels of labile iron pool and the functions of transferrin receptor-1 on cholangiocarcinoma development were also identified. Iron deposition was determined using the Prussian blue staining method in human cholangiocarcinoma tissues. We investigated the alteration of iron regulatory proteins including transferrin, transferrin receptor-1, ferritin, ferroportin, hepcidin, and divalent metal transporter-1 in cholangiocarcinoma tissues using immunohistochemistry. The clinicopathological data of cholangiocarcinoma patients and the expressions of proteins were analyzed. Moreover, the level of intracellular labile iron pool in cholangiocarcinoma cell lines was identified by the RhoNox-1 staining method. We further demonstrated transferrin receptor-1 functions on cell proliferation and migration upon small interfering RNA for human transferrin receptor 1 transfection. Results show that Iron was strongly stained in tumor tissues, whereas negative staining was observed in normal bile ducts of healthy donors. Interestingly, high iron accumulation was significantly correlated with poor prognosis of cholangiocarcinoma patients. The expressions of iron regulatory proteins in human cholangiocarcinoma tissues and normal liver from cadaveric donors revealed that transferrin receptor-1 expression was increased in the cancer cells of cholangiocarcinoma tissues when compared with the adjacent normal bile ducts and was significantly correlated with cholangiocarcinoma metastasis. Labile iron pool level and transferrin receptor-1 expression were significantly increased in KKU-214 and KKU-213 when compared with cholangiocyte

  19. Positioning high-dose radiation in multidisciplinary management of unresectable cholangiocarcinomas: review of current evidence.

    PubMed

    Chopra, Supriya; Mathew, Ashwathy S; Engineer, Reena; Shrivastava, Shyam K

    2014-09-01

    Cholangiocarcinoma is a rare malignancy of the bile ducts. The current standard of care for unresectable nonmetastatic disease is doublet systemic chemotherapy, which provides a median survival of 11.7 months. Although chemoradiation is a therapeutic option that provides almost equivalent or superior survival, the lack of level I evidence presents a major hurdle in routinely recommending it within multidisciplinary clinics. This mini review presents the current evidence on the use of chemoradiation for unresectable nonmetastatic cholangiocarcinoma and rationale for positioning it within multidisciplinary management of unresectable cholangiocarcinomas.

  20. Intrahepatic clear cell cholangiocarcinoma - An uncommon histologic subtype: case report and literature review.

    PubMed

    Fernandes, Samuel Raimundo; Baldaia, Cilénia; Pinto Marques, Hugo; Tortosa, Francisco; Ramalho, Fernando

    2017-02-03

    Clear-cell cholangiocarcinoma is a very uncommon variant of cholangiocarcinoma with a largely unknown natural history and prognosis. We report a case of a 51-year-old previously healthy woman presenting with a large liver nodule found on routine imaging. Needle biopsy of the lesion suggested a non-hepatocellular carcinoma. After extensive workup for other primary neoplasms, the patient underwent a partial hepatectomy. Histopathology was compatible with a moderately differentiated clear-cell cholangiocarcinoma. There was no evidence of liver disease in the remaining tissue. The patient underwent chemotherapy and remains in clinical remission after two years.

  1. Clonorchis sinensis excretory-secretory products regulate migration and invasion in cholangiocarcinoma cells via extracellular signal-regulated kinase 1/2/nuclear factor-κB-dependent matrix metalloproteinase-9 expression.

    PubMed

    Pak, Jhang Ho; Shin, Jimin; Song, In-Sung; Shim, Sungbo; Jang, Sung-Wuk

    2017-01-01

    Matrix metalloproteinase-9 plays an important role in the invasion and metastasis of various types of cancer cells. We have previously reported that excretory-secretory products from Clonorchis sinensis increases matrix metalloproteinase-9 expression. However, the regulatory mechanisms through which matrix metalloproteinase-9 expression affects cholangiocarcinoma development remain unclear. In the current study, we examined the potential role of excretory-secretory products in regulating the migration and invasion of various cholangiocarcinoma cell lines. We demonstrated that excretory-secretory products significantly induced matrix metalloproteinase-9 expression and activity in a concentration-dependent manner. Reporter gene and chromatin immunoprecipitation assays showed that excretory-secretory products induced matrix metalloproteinase-9 expression by enhancing the activity of nuclear factor-kappa B. Moreover, excretory-secretory products induced the degradation and phosphorylation of IκBα and stimulated nuclear factor-kappa B p65 nuclear translocation, which was regulated by extracellular signal-regulated kinase 1/2. Taken together, our findings indicated that the excretory-secretory product-dependent enhancement of matrix metalloproteinase-9 activity and subsequent induction of IκBα and nuclear factor-kappa B activities may contribute to the progression of cholangiocarcinoma.

  2. High glucose levels boost the aggressiveness of highly metastatic cholangiocarcinoma cells via O-GlcNAcylation

    PubMed Central

    Phoomak, Chatchai; Vaeteewoottacharn, Kulthida; Silsirivanit, Atit; Saengboonmee, Charupong; Seubwai, Wunchana; Sawanyawisuth, Kanlayanee; Wongkham, Chaisiri; Wongkham, Sopit

    2017-01-01

    Increased glucose utilization is a feature of cancer cells to support cell survival, proliferation, and metastasis. An association between diabetes mellitus and cancer progression was previously demonstrated in cancers including cholangiocarcinoma (CCA). This study was aimed to determine the effects of high glucose on protein O-GlcNAcylation and metastatic potentials of CCA cells. Two pairs each of the parental low metastatic and highly metastatic CCA sublines were cultured in normal (5.6 mM) or high (25 mM) glucose media. The migration and invasion abilities were determined and underlying mechanisms were explored. Results revealed that high glucose promoted migration and invasion of CCA cells that were more pronounced in the highly metastatic sublines. Concomitantly, high glucose increased global O-GlcNAcylated proteins, the expressions of vimentin, hexokinase, glucosamine-fructose-6-phosphate amidotransferase (GFAT) and O-GlcNAc transferase of CCA cells. The glucose level that promoted migration/invasion was shown to be potentiated by the induction of GFAT, O-GlcNAcylation and an increase of O-GlcNAcylated vimentin and vimentin expression. Treatment with a GFAT inhibitor reduced global O-GlcNAcylated proteins, vimentin expression, and alleviated cell migration. Altogether, these results suggested the role of high glucose enhanced CCA metastasis via modulation of O-GlcNAcylation, through the expressions of GFAT and vimentin. PMID:28262738

  3. Corilagin suppresses cholangiocarcinoma progression through Notch signaling pathway in vitro and in vivo

    PubMed Central

    GU, YUE; XIAO, LINFENG; MING, YANLIN; ZHENG, ZHIZHONG; LI, WENGANG

    2016-01-01

    Corilagin is a natural plant polyphenol tannic acid with antitumor, anti-inflammatory, and anti-oxidative properties. However, the mechanisms of its actions are largely unknown. Our group reported that corilagin could induce cell inhibition in human breast cancer cell line MCF-7 and human liver hepatocellular carcinoma cell lines HepG2. We report here that corilagin inhibits cholangiocarcinoma (CCA) development through regulating Notch signaling pathway. We found that, in vitro, corilagin inhibited CCA cell proliferation, migration and invasion, promoted CCA cell apoptosis, and inhibited Notch1 and Notch signaling pathway protein expression. Co-immunoprecipitation was used to establish Notch intracellular domain (NICD) interaction with MAML1 and P300 in CCA. Importantly, corilagin reduced Hes1 mRNA level through inhibiting Hes1 promoter activity. In nude mice, corilagin inhibited CCA growth and repressed the expression of Notch1 and mTOR. These results indicate that corilagin may control CCA cell growth by downregulating the expression of Notch1. Therefore, our findings suggest that corilagin may have the potential to become a new therapeutic drug for human CCA. PMID:26935808

  4. Stent Placement With or Without Photodynamic Therapy Using Porfimer Sodium as Palliative Treatment in Treating Patients With Stage III or Stage IV Cholangiocarcinoma That Cannot Be Removed By Surgery

    ClinicalTrials.gov

    2013-04-02

    Cholangiocarcinoma of the Extrahepatic Bile Duct; Cholangiocarcinoma of the Gallbladder; Unresectable Extrahepatic Bile Duct Cancer; Unresectable Gallbladder Cancer; Recurrent Extrahepatic Bile Duct Cancer; Recurrent Gallbladder Cancer

  5. [A Case of Cholangiocarcinoma with Intestinal Malrotation Treated with Pancreaticoduodenectomy].

    PubMed

    Saito, Yurina; Miyamoto, Atsushi; Maeda, Sakae; Hama, Naoki; Haraguchi, Naotsugu; Yamamoto, Kazuyoshi; Miyake, Masakazu; Nishikawa, Kazuhiro; Miyazaki, Michihiko; Ikeda, Masataka; Hirao, Motohiro; Sekimoto, Mitsugu; Nakamori, Shoji

    2015-11-01

    We report a case of cholangiocarcinoma with intestinal malrotation that was treated with pancreaticoduodenectomy. The patient was a 74-year-old man, who underwent laboratory screening and was subsequently found to have elevated γglutamyl transpeptidase levels. Preoperative ultrasonography revealed intrahepatic bile duct dilatation. Endoscopic retrograde cholangiopancreatography demonstrated a filling defect in the common bile duct and cytology of the bile demonstrated the presence of an adenocarcinoma. On preoperative computed tomography (CT), the SMV was located on the left side of the SMA, which showed the SMV rotation sign. Additionally, the small intestine and the colon were deviated to the right and left side of abdominal cavity, respectively. We diagnosed the patient with cholangiocarcinoma with intestinal malrotation and preduodenal portal vein involvement using the CT scan, and performed pancreaticoduodenectomy. Since the ligament of Treitz was absent during surgery, we diagnosed this as a case of the nonrotation type of malrotation. The postoperative course was uneventful and the patient was discharged from the hospital 42 days after the surgery. Anomalies of the portal venous system are so rare that recognition of its variation is important in order to avoid accidental injuries during the operation.

  6. Current Diagnostic and Management Options in Perihilar Cholangiocarcinoma

    PubMed Central

    Rizvi, Sumera; Gores, Gregory J.

    2014-01-01

    Cholangiocarcinomas (CCA) are heterogeneous biliary tract tumors with dismal prognosis. Perihilar cholangiocarcinoma (pCCA) involves the large bile ducts of the hepatic hilum, and is the most common type of CCA. Primary sclerosing cholangitis (PSC) is an established risk factor for pCCA. Although the diagnosis of pCCA is challenging, recent advances have been made including cytologic techniques such as fluorescence in situ hybridization. Endoscopic ultrasound with sampling of regional lymph nodes is emerging as a valuable diagnostic modality in the diagnosis and staging of pCCA. Curative treatment options are limited to early stage disease, and include surgical resection and liver transplantation after neoadjuvant therapy. This underscores the importance of early detection, and the need for development of innovative diagnostic tools such as biomarkers. A dense desmoplastic tumor stroma plays an integral role in pCCA progression. The tumor stroma represents an additional target for development of new therapies. Herein, we discuss these advances in the diagnosis and treatment of pCCA. PMID:24860985

  7. Bisphenol-A rapidly promotes dynamic changes in hippocampal dendritic morphology through estrogen receptor-mediated pathway by concomitant phosphorylation of NMDA receptor subunit NR2B

    SciTech Connect

    Xu Xiaohong Ye Yinping; Li Tao; Chen Lei; Tian Dong; Luo Qingqing; Lu Mei

    2010-12-01

    Bisphenol-A (BPA) is known to be a potent endocrine disrupter. Evidence is emerging that estrogen exerts a rapid influence on hippocampal synaptic plasticity and the dendritic spine density, which requires activation of NMDA receptors. In the present study, we investigated the effects of BPA (ranging from 1 to 1000 nM), focusing on the rapid dynamic changes in dendritic filopodia and the expressions of estrogen receptor (ER) {beta} and NMDA receptor, as well as the phosphorylation of NMDA receptor subunit NR2B in the cultured hippocampal neurons. A specific ER antagonist ICI 182,780 was used to examine the potential involvement of ERs. The results demonstrated that exposure to BPA (ranging from 10 to 1000 nM) for 30 min rapidly enhanced the motility and the density of dendritic filopodia in the cultured hippocampal neurons, as well as the phosphorylation of NR2B (pNR2B), though the expressions of NMDA receptor subunits NR1, NR2B, and ER{beta} were not changed. The antagonist of ERs completely inhibited the BPA-induced increases in the filopodial motility and the number of filopodia extending from dendrites. The increased pNR2B induced by BPA (100 nM) was also completely eliminated. Furthermore, BPA attenuated the effects of 17{beta}-estradiol (17{beta}-E{sub 2}) on the dendritic filopodia outgrowth and the expression of pNR2B when BPA was co-treated with 17{beta}-E{sub 2}. The present results suggest that BPA, like 17{beta}-E{sub 2}, rapidly results in the enhanced motility and density of dendritic filopodia in the cultured hippocampal neurons with the concomitant activation of NMDA receptor subunit NR2B via an ER-mediated signaling pathway. Meanwhile, BPA suppressed the enhancement effects of 17{beta}-E{sub 2} when it coexists with 17{beta}-E{sub 2}. These results provided important evidence suggesting the neurotoxicity of the low levels of BPA during the early postnatal development of the brain.

  8. Dopamine promotes NMDA receptor hypofunction in the retina through D1 receptor-mediated Csk activation, Src inhibition and decrease of GluN2B phosphorylation

    PubMed Central

    Socodato, Renato; Santiago, Felipe N.; Portugal, Camila C.; Domith, Ivan; Encarnação, Thaísa G.; Loiola, Erick C.; Ventura, Ana L. M.; Cossenza, Marcelo; Relvas, João B.; Castro, Newton G.; Paes-de-Carvalho, Roberto

    2017-01-01

    Dopamine and glutamate are critical neurotransmitters involved in light-induced synaptic activity in the retina. In brain neurons, dopamine D1 receptors (D1Rs) and the cytosolic protein tyrosine kinase Src can, independently, modulate the behavior of NMDA-type glutamate receptors (NMDARs). Here we studied the interplay between D1Rs, Src and NMDARs in retinal neurons. We reveal that dopamine-mediated D1R stimulation provoked NMDAR hypofunction in retinal neurons by attenuating NMDA-gated currents, by preventing NMDA-elicited calcium mobilization and by decreasing the phosphorylation of NMDAR subunit GluN2B. This dopamine effect was dependent on upregulation of the canonical D1R/adenylyl cyclase/cAMP/PKA pathway, of PKA-induced activation of C-terminal Src kinase (Csk) and of Src inhibition. Accordingly, knocking down Csk or overexpressing a Csk phosphoresistant Src mutant abrogated the dopamine-induced NMDAR hypofunction. Overall, the interplay between dopamine and NMDAR hypofunction, through the D1R/Csk/Src/GluN2B pathway, might impact on light-regulated synaptic activity in retinal neurons. PMID:28098256

  9. Novel B55α-PP2A mutations in AML promote AKT T308 phosphorylation and sensitivity to AKT inhibitor-induced growth arrest

    PubMed Central

    Shouse, Geoffrey; de Necochea-Campion, Rosalia; Mirshahidi, Saied; Liu, Xuan; Chen, Chien-Shing

    2016-01-01

    Activation of the Protein Kinase B (PKB), or AKT pathway has been shown to correlate with acute myeloid leukemia (AML) prognosis. B55α-Protein Phosphatase 2A (PP2A) has been shown to dephosphorylate AKT at Thr-308 rendering it inactive. In fact, low expression of the PP2A regulatory subunit B55α was associated with activated phospho-AKT and correlated with inferior outcomes in AML. Despite this fact, no studies have specifically demonstrated a mechanism whereby B55α expression is regulated in AML. In this study, we demonstrate novel loss of function mutations in the PPP2R2A gene identified in leukemic blasts from three AML patients. These mutations eliminate B55α protein expression thereby allowing constitutive AKT activation. In addition, leukemic blasts with PPP2R2A gene mutation were more sensitive to treatment with the AKT inhibitor MK2206, but less responsive to the PP2A activator FTY720. Using leukemia cell lines, we further demonstrate that B55α expression correlates with AKT Thr-308 phosphorylation and predicts responsiveness to AKT inhibition and PP2A activation. Together our data illustrate the importance of the B55α-PP2A-AKT pathway in leukemogenesis. Screening for disruptions in this pathway at initial AML diagnosis may predict response to targeted therapies against AKT and PP2A. PMID:27531894

  10. ASF1a Promotes Non-homologous End Joining Repair by Facilitating Phosphorylation of MDC1 by ATM at Double-Strand Breaks.

    PubMed

    Lee, Kyung Yong; Im, Jun-Sub; Shibata, Etsuko; Dutta, Anindya

    2017-09-13

    Double-strand breaks (DSBs) of DNA in eukaryotic cells are predominantly repaired by non-homologous end joining (NHEJ). The histone chaperone anti-silencing factor 1a (ASF1a) interacts with MDC1 and is recruited to sites of DSBs to facilitate the interaction of phospho-ATM with MDC1 and phosphorylation of MDC1, which are required for the recruitment of RNF8/RNF168 histone ubiquitin ligases. Thus, ASF1a deficiency reduces histone ubiquitination at DSBs, decreasing the recruitment of 53BP1, and decreases NHEJ, rendering cells more sensitive to DSBs. This role of ASF1a in DSB repair cannot be provided by the closely related ASF1b and does not require its histone chaperone activity. Homozygous deletion of ASF1A is seen in 10%-15% of certain cancers, suggesting that loss of NHEJ may be selected in some malignancies and that the deletion can be used as a molecular biomarker for cancers susceptible to radiotherapy or to DSB-inducing chemotherapy. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. Phosphorylation of ezrin-radixin-moesin-binding phosphoprotein 50 (EBP50) by Akt promotes stability and mitogenic function of S-phase kinase-associated protein-2 (Skp2).

    PubMed

    Song, Gyun Jee; Leslie, Kristen L; Barrick, Stacey; Mamonova, Tatyana; Fitzpatrick, Jeremy M; Drombosky, Kenneth W; Peyser, Noah; Wang, Bin; Pellegrini, Maria; Bauer, Philip M; Friedman, Peter A; Mierke, Dale F; Bisello, Alessandro

    2015-01-30

    The regulation of the cell cycle by the ubiquitin-proteasome system is dependent on the activity of E3 ligases. Skp2 (S-phase kinase associated protein-2) is the substrate recognition subunit of the E3 ligase that ubiquitylates the cell cycle inhibitors p21(cip1) and p27(kip1) thus promoting cell cycle progression. Increased expression of Skp2 is frequently observed in diseases characterized by excessive cell proliferation, such as cancer and neointima hyperplasia. The stability and cellular localization of Skp2 are regulated by Akt, but the molecular mechanisms underlying these effects remain only partly understood. The scaffolding protein Ezrin-Binding Phosphoprotein of 50 kDa (EBP50) contains two PDZ domains and plays a critical role in the development of neointimal hyperplasia. Here we report that EBP50 directly binds Skp2 via its first PDZ domain. Moreover, EBP50 is phosphorylated by Akt on Thr-156 within the second PDZ domain, an event that allosterically promotes binding to Skp2. The interaction with EBP50 causes cytoplasmic localization of Skp2, increases Skp2 stability and promotes proliferation of primary vascular smooth muscle cells. Collectively, these studies define a novel regulatory mechanism contributing to aberrant cell growth and highlight the importance of scaffolding function of EBP50 in Akt-dependent cell proliferation.

  12. Colon Mass as a Secondary Metastasis from Cholangiocarcinoma: A Diagnostic and Therapeutic Dilemma.

    PubMed

    Niazi, Azfar; Saif, Muhammad W

    2016-07-22

    Cholangiocarcinoma (bile ducts cancer) is a rare and aggressive form of cancer. It metastasizes frequently to liver, peritoneum, and lungs. Colon metastasis is extremely uncommon. We report here a 70-year-old male who was diagnosed with cholangiocarcinoma for which he underwent a Whipple procedure. Fifteen months later, a CT scan revealed mural thickening in the colon; this was supplemented with a PET scan, which confirmed this mass. Histological diagnosis of metastatic cholangiocarcinoma to the colon was made and the patient was treated with chemotherapy. Although rare, cholangiocarcinoma metastasis can be found in the colon. A high index of suspicion is required to diagnose and treat early. More cases need to be reported to find out further about the prognosis of the disease.

  13. Living Donor Liver Transplantation for Combined Hepatocellular Carcinoma and Cholangiocarcinoma: Experience of a Single Center.

    PubMed

    Chang, Cheng-Chih; Chen, Ying-Ju; Huang, Tzu-Hao; Chen, Chun-Han; Kuo, Fang-Ying; Eng, Hock-Liew; Yong, Chee-Chien; Liu, Yueh-Wei; Lin, Ting-Lung; Li, Wei-Feng; Lin, Yu-Hung; Lin, Chih-Che; Wang, Chih-Chi; Chen, Chao-Long

    2017-02-28

    BACKGROUND Because the outcome of liver transplantation for cholangiocarcinoma is often poor, cholangiocarcinoma is a contraindication for liver transplantation in most centers. Combined hepatocellular carcinoma and cholangiocarcinoma is a rare type of primary hepatic malignancy containing features of hepatocellular carcinoma and cholangiocarcinoma. Diagnosing combined hepatocellular carcinoma and cholangiocarcinoma pre-operatively is difficult. Because of sparse research presentations worldwide, we report our experience with living donor liver transplantation for combined hepatocellular carcinoma and cholangiocarcinoma. MATERIAL AND METHODS A total of 710 patients underwent living donor liver transplantation at our institution from April 2006 to June 2014; 377 of them received transplantation because of hepatocellular carcinoma with University of California San Francisco (UCSF) staging criteria fulfilled pre-operatively. Eleven patients (2.92%) were diagnosed with combined hepatocellular carcinoma and cholangiocarcinoma confirmed pathologically from explant livers; we reviewed these cases retrospectively. Long-term survival was compared between patients diagnosed with combined hepatocellular carcinoma and cholangiocarcinoma and patients diagnosed with hepatocellular carcinoma. RESULTS The mean age of the patients in our series was 60.2 years, and the median follow-up period was 23.9 months. Four patients were diagnosed with a recurrence during the follow-up period, including one intra-hepatic and three extra-hepatic recurrences. Four patients died due to tumor recurrence. Except for patients with advanced-stage cancer, disease-free survival of patients with combined hepatocellular carcinoma and cholangiocarcinoma compared with that of patients with hepatocellular carcinoma was 80% versus 97.2% in 1 year, and 46.7% versus 92.5% in 3 years (p<0.001), and overall survival was 90% versus 97.2% in 1 year, and 61.7% versus 95.1% in 3 years (p<0.001). CONCLUSIONS

  14. Inhibition of hypoxia inducible factor 1 and topoisomerase with acriflavine sensitizes perihilar cholangiocarcinomas to photodynamic therapy

    PubMed Central

    Krekorian, Massis; Alles, Lindy K.; van Wijk, Albert C.; Mackaaij, Claire; Verheij, Joanne; van der Wal, Allard C.; van Gulik, Thomas M.; Storm, Gert; Heger, Michal

    2016-01-01

    Background: Photodynamic therapy (PDT) induces tumor cell death by oxidative stress and hypoxia but also survival signaling through activation of hypoxia-inducible factor 1 (HIF-1). Since perihilar cholangiocarcinomas are relatively recalcitrant to PDT, the aims were to (1) determine the expression levels of HIF-1-associated proteins in human perihilar cholangiocarcinomas, (2) investigate the role of HIF-1 in PDT-treated human perihilar cholangiocarcinoma cells, and (3) determine whether HIF-1 inhibition reduces survival signaling and enhances PDT efficacy. Results: Increased expression of VEGF, CD105, CD31/Ki-67, and GLUT-1 was confirmed in human perihilar cholangiocarcinomas. PDT with liposome-delivered zinc phthalocyanine caused HIF-1α stabilization in SK-ChA-1 cells and increased transcription of HIF-1α downstream genes. Acriflavine was taken up by SK-ChA-1 cells and translocated to the nucleus under hypoxic conditions. Importantly, pretreatment of SK-ChA-1 cells with acriflavine enhanced PDT efficacy via inhibition of HIF-1 and topoisomerases I and II. Methods: The expression of VEGF, CD105, CD31/Ki-67, and GLUT-1 was determined by immunohistochemistry in human perihilar cholangiocarcinomas. In addition, the response of human perihilar cholangiocarcinoma (SK-ChA-1) cells to PDT with liposome-delivered zinc phthalocyanine was investigated under both normoxic and hypoxic conditions. Acriflavine, a HIF-1α/HIF-1β dimerization inhibitor and a potential dual topoisomerase I/II inhibitor, was evaluated for its adjuvant effect on PDT efficacy. Conclusions: HIF-1, which is activated in human hilar cholangiocarcinomas, contributes to tumor cell survival following PDT in vitro. Combining PDT with acriflavine pretreatment improves PDT efficacy in cultured cells and therefore warrants further preclinical validation for therapy-recalcitrant perihilar cholangiocarcinomas. PMID:26657503

  15. Paraneoplastic Necrotizing Autoimmune Myopathy in a Patient Undergoing Laparoscopic Pancreatoduodenectomy for Distal Cholangiocarcinoma

    PubMed Central

    van Dijk, Stefan; van der Kooi, Anneke J.; Aronica, Eleonora; van Gulik, Thomas M.; Busch, Olivier R.; Besselink, Marc G.

    2016-01-01

    A 73-year-old male presented with jaundice and severe muscle weakness. He was diagnosed with distal cholangiocarcinoma and paraneoplastic necrotizing autoimmune myopathy (NAM). Treatment of NAM consisted of dexamethasone pulse therapy, prednisone, and single-dose intravenous immunoglobulin. The distal cholangiocarcinoma was resected through a total laparoscopic pancreatoduodenectomy. After hospital discharge, muscle strength initially increased postoperatively; however, pneumonia resulted in the deterioration of his general condition and death 5 months after the diagnosis of paraneoplastic NAM. PMID:27843429

  16. Pesticides, fresh water fish, liver flukes and nitrosamines: A story of cholangiocarcinoma development in Thailand.

    PubMed

    Wiwanitkit, Viroj

    2009-01-01

    Cholangiocarcinoma is a common hepatobiliary carcinoma in Thailand. It is believed that both chronic exposure to liver fluke infestation and nitrosamine exposure are the two main underlying factors leading to the carcinogenesis. Here, the author further extrapolates and proposes a new hypothesis based on the environmental ecological data that the stimulation of fresh water fish by contaminated pesticide in water reservoirs might be a possible background of the high prevalence of cholangiocarcinoma in Thailand.

  17. Endothelial CD47 promotes Vascular Endothelial-cadherin tyrosine phosphorylation and participates in T-cell recruitment at sites of inflammation in vivo

    PubMed Central

    Azcutia, Veronica; Stefanidakis, Michael; Tsuboi, Naotake; Mayadas, Tanya; Croce, Kevin J.; Fukuda, Daiju; Aikawa, Masanori; Newton, Gail; Luscinskas, Francis W.

    2012-01-01

    At sites of inflammation, endothelial adhesion molecules bind leukocytes and transmit signals required for transendothelial migration (TEM). We previously reported that adhesive interactions between endothelial cell CD47 and leukocyte Signal Regulatory Proteinγ (SIRPγ) regulate human T-cell TEM. The role of endothelial CD47 in T-cell TEM in vivo, however, has not been explored. Here, CD47−/− mice showed reduced recruitment of blood T-cells as well as neutrophils and monocytes in a dermal air pouch model of TNF-α induced inflammation. Reconstitution of CD47−/− mice with wild type bone marrow (BM) cells did not restore leukocyte recruitment to the air pouch, indicating a role for endothelial CD47. The defect in leukocyte TEM in the CD47−/− endothelium was corroborated by intravital microscopy of inflamed cremaster muscle microcirculation in BM chimera mice. In an in vitro human system, CD47 on both HUVEC and T-cells were required for TEM. Although previous studies showed CD47-dependent signaling required Gαi coupled pathways, this was not the case for endothelial CD47 because pertussis toxin (PTX), which inactivates Gαi, had no inhibitory effect, whereas Gαi was required by the T-cell for TEM. We next investigated the endothelial CD47-dependent signaling events that accompany leukocyte TEM. Antibody-induced crosslinking of CD47 revealed robust actin cytoskeleton reorganization and Src and Pyk-2 kinase dependent tyrosine phosphorylation of the VE-cadherin cytoplasmic tail. This signaling was PTX insensitive suggesting that endothelial CD47 signaling is independent of Gαi. These findings suggest that engagement of endothelial CD47 by its ligands triggers “outside-in” signals in endothelium that facilitate leukocyte TEM. PMID:22815286

  18. Cholangiocarcinoma presenting as hemobilia and recurrent iron-deficiency anemia: a case report

    PubMed Central

    2010-01-01

    Introduction Iron-deficiency anemia is a relatively common presenting feature of several gastrointestinal malignancies. However, cholangiocarcinoma has rarely been reported as an underlying cause. The association of cholangiocarcinoma with the rare clinical finding of hemobilia is also highly unusual. To our knowledge, this is the first case report of cholangiocarcinoma presenting with acute hemobilia and chronic iron-deficiency anemia. Case presentation We report the case of a Caucasian, 84-year-old woman presenting with recurrent, severe iron-deficiency anemia who was eventually diagnosed with intra-hepatic cholangiocarcinoma, following an acute episode of hemobilia. A right hepatectomy was subsequently performed with curative intent, and our patient has now fully recovered. Conclusion This is a rare example of hemobilia and chronic iron-deficiency anemia in association with cholangiocarcinoma. We suggest that a diagnosis of cholangiocarcinoma should be considered in patients who present with iron-deficiency anemia of unknown cause, particularly in the presence of abnormal liver function. PMID:20459809

  19. Olaparib in Treating Patients With Advanced Glioma, Cholangiocarcinoma, or Solid Tumors With IDH1 or IDH2 Mutations

    ClinicalTrials.gov

    2017-09-12

    Advanced Malignant Solid Neoplasm; Glioblastoma; Grade II Glioma; IDH1 Gene Mutation; IDH2 Gene Mutation; Recurrent Cholangiocarcinoma; Recurrent Glioma; Recurrent Malignant Solid Neoplasm; WHO Grade III Glioma

  20. Pan-mTOR inhibitor MLN0128 is effective against intrahepatic cholangiocarcinoma in mice.

    PubMed

    Zhang, Shanshan; Song, Xinhua; Cao, Dan; Xu, Zhong; Fan, Biao; Che, Li; Hu, Junjie; Chen, Bin; Dong, Mingjie; Pilo, Maria G; Cigliano, Antonio; Evert, Katja; Ribback, Silvia; Dombrowski, Frank; Pascale, Rosa M; Cossu, Antonio; Vidili, Gianpaolo; Porcu, Alberto; Simile, Maria M; Pes, Giovanni M; Giannelli, Gianluigi; Gordan, John; Wei, Lixin; Evert, Matthias; Cong, Wenming; Calvisi, Diego F; Chen, Xin

    2017-07-19

    Intrahepatic cholangiocarcinoma (ICC) is a lethal malignancy without effective treatment options. MLN0128, a second generation pan-mTOR inhibitor, shows efficacy for multiple tumor types. We evaluated the therapeutic potential of MLN0128 vs. gemcitabine/oxaliplatin in a novel ICC mouse model. We established a novel ICC mouse model via hydrodynamic transfection of activated forms of AKT (myr-AKT) and Yap (YapS127A) protooncogenes (that will be referred to as AKT/YapS127A). Genetic approaches were applied to study the requirement of mTORC1 and mTORC2 in mediating AKT/YapS127A driven tumorigenesis. Gemcitabine/oxaliplatin and MLN0128 were administered in AKT/YapS127A tumor-bearing mice to study their anti-tumor efficacy in vivo. Multiple human ICC cell lines were used for in vitro experiments. Hematoxylin and eosin staining, immunohistochemistry and immunoblotting were applied for the characterization and mechanistic study. Co-expression of myr-AKT and YapS127A promoted ICC development in mice. Both mTORC1 and mTORC2 complexes were required for AKT/YapS127A ICC development. Gemcitabine/oxaliplatin had limited efficacy in treating late stage AKT/YapS127A ICC. In contrast, partial tumor regression was achieved when MLN0128 was applied in the late stage of AKT/YapS127A cholangiocarcinogenesis. Furthermore, when MLN0128 was administered in the early stage of AKT/YapS127A carcinogenesis, it led to disease stabilization. Mechanistically, MLN0128 efficiently inhibited AKT/mTOR signaling both in vivo and in vitro, inducing strong ICC cell apoptosis and only marginally affecting proliferation. This study suggests that mTOR kinase inhibitors may be beneficial for the treatment of ICC, even in tumors that are resistant to standard of care chemotherapeutics, such as gemcitabine/oxaliplatin-based regimens, especially in the subset of tumors exhibiting activated AKT/mTOR cascade. Lay summary: We established a novel mouse model of intrahepatic cholangiocarcinoma (ICC). Using this

  1. A Resveratrol Analogue Promotes ERKMAPK–Dependent Stat3 Serine and Tyrosine Phosphorylation Alterations and Antitumor Effects In Vitro against Human Tumor Cells

    PubMed Central

    Chelsky, Zachary L.; Yue, Peibin; Kondratyuk, Tamara P.; Paladino, David; Pezzuto, John M.; Cushman, Mark

    2015-01-01

    (E)-4-(3,5-dimethoxystyryl)phenyl acetate (Cmpd1) is a resveratrol analog that preferentially inhibits glioma, breast, and pancreatic cancer cell growth, with IC50 values of 6–19 μM. Notably, the human U251MG glioblastoma tumor line is the most sensitive, with an IC50 of 6.7 μM, compared with normal fibroblasts, which have an IC50 > 20 μM. Treatment of U251MG cells that harbor aberrantly active signal transducer and activator of transcription (Stat) 3 with Cmpd1 suppresses Stat3 tyrosine705 phosphorylation in a dose-dependent manner in parallel with the induction of pserine727 Stat3 and extracellular signal-regulated kinase/mitogen-activated protein kinase 1/2 (pErk1/2MAPK). Inhibition of pErk1/2MAPK induction by the mitogen-activated protein/extracellular signal-regulated kinase kinase inhibitor PD98059 [2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one] blocked both the pserine727 Stat3 induction and ptyrosine705 Stat3 suppression by Cmpd1, indicating dependency on the mitogen-activated protein/extracellular signal-regulated kinase kinase–Erk1/2MAPK pathway for Cmpd1-induced modulation of Stat3 signaling. Cmpd1 also blocked epidermal growth factor–stimulated pStat1 induction, whereas upregulating pSrc, pAkt, p-p38, pHeat shock protein 27, and pmammalian target of rapamycin levels. However, pJanus kinase 2 and pEpidermal growth factor receptor levels were not significantly altered. Treatment of U251MG cells with Cmpd1 reduced in vitro colony formation, induced cell cycle arrest in the G2/M phase and cleavage of caspases 3, 8, and 9 and poly(ADP ribose) polymerase, and suppressed survivin, myeloid cell leukemia 1, Bcl-xL, cyclin D1, and cyclin B1 expression. Taken together, these data identify a novel mechanism for the inhibition of Stat3 signaling by a resveratrol analog and suggest that the preferential growth inhibitory effects of Cmp1 occur in part by Erk1/2MAPK-dependent modulation of constitutively active Stat3. PMID:26138072

  2. c-Jun localizes to the nucleus independent of its phosphorylation by and interaction with JNK and vice versa promotes nuclear accumulation of JNK

    SciTech Connect

    Schreck, Ilona; Al-Rawi, Marco; Mingot, Jose-Manuel; Scholl, Christine; Diefenbacher, Markus Elmar; O'Donnell, Paul; Bohmann, Dirk; Weiss, Carsten

    2011-04-22

    Highlights: {yields} HSP70, Ku70 and 80 as well as importin 8 are novel interactors of c-Jun. {yields} Nuclear accumulation of c-Jun does not require its functions as a transcription factor. {yields} Nuclear accumulation of c-Jun does not require the interaction with its kinase JNK. {yields} Nuclear accumulation of JNK is regulated by interaction with c-Jun. -- Abstract: In order to activate gene expression, transcription factors such as c-Jun have to reside in the nucleus. The abundance of c-Jun in the nucleus correlates with the activity of its target genes. As a consequence of excessive c-Jun activation, cells undergo apoptosis or changes in differentiation whereas decreased c-Jun function can reduce proliferation. In the present study we addressed how nuclear accumulation of the transcription factor c-Jun is regulated. First, we analyzed which functions of c-Jun are required for efficient nuclear accumulation. Mutants of c-Jun deficient in dimerization or DNA-binding show no defect in nuclear transport. Furthermore, c-Jun import into the nucleus of living cells occurred when the c-Jun phosphorylation sites were mutated as well in cells that lack the major c-Jun kinase, JNK, suggesting that c-Jun transport into the nucleus does not require JNK signaling. Conversely, however, binding of c-Jun seemed to enhance nuclear accumulation of JNK. In order to identify proteins that might be relevant for the nuclear translocation of c-Jun we searched for novel binding partners by a proteomic approach. In addition to the heat shock protein HSP70 and the DNA damage repair factors Ku70 and 80, we isolated human importin 8 as a novel interactor of c-Jun. Interaction of Imp 8 with c-Jun in human cells was confirmed by co-immunoprecipitation experiments. Nuclear accumulation of c-Jun does not require its functions as a transcription factor or the interaction with its kinase JNK. Interestingly, nuclear accumulation of JNK is regulated by interaction with c-Jun. Unraveling the

  3. Whole-Genome and Epigenomic Landscapes of Etiologically Distinct Subtypes of Cholangiocarcinoma

    DOE PAGES

    Jusakul, Apinya; Cutcutache, Ioana; Yong, Chern Han; ...

    2017-06-30

    Cholangiocarcinoma (CCA) is a hepatobiliary malignancy exhibiting high incidence in countries with endemic liver-fluke infection. We analysed 489 CCAs from 10 countries, combining whole-genome (71 cases), targeted/exome, copy-number, gene expression, and DNA methylation information. Integrative clustering defined four CCA clusters - Fluke- Positive CCAs (Clusters 1/2) are enriched in ERBB2 amplifications and TP53 mutations, conversely Fluke-Negative CCAs (Clusters 3/4) exhibit high copy-number alterations and PD-1/PD-L2 expression, or epigenetic mutations (IDH1/2, BAP1) and FGFR/PRKA-related gene rearrangements. Whole-genome analysis highlighted FGFR2 3’UTR deletion as a mechanism of FGFR2 upregulation. Integration of non-coding promoter mutations with protein-DNA binding profiles demonstrates pervasive modulation ofmore » H3K27me3-associated sites in CCA. Clusters 1 and 4 exhibit distinct DNA hypermethylation patterns targeting either CpG islands or shores - mutation signature and subclonality analysis suggests that these reflect different mutational pathways. Lastly, our results exemplify how genetics, epigenetics and environmental carcinogens can interplay across different geographies to generate distinct molecular subtypes of cancer.« less

  4. Roles of liver fluke infection as risk factor for cholangiocarcinoma.

    PubMed

    Sithithaworn, Paiboon; Yongvanit, Puangrat; Duenngai, Kunyarat; Kiatsopit, Nadda; Pairojkul, Chawalit

    2014-05-01

    Several factors are known to be associated with risk of cholangiocarcinoma (CCA) and infection with the liver flukes, Opisthorchis viverrini and Clonorchis sinensis, has often been singled out as the leading risk factor in east and southeast Asia. In this review, current knowledge of their biology, life cycle, and pathogenesis of O. viverrini, and its role as a carcinogenic parasite are presented. The trends of age-specific incidence of liver cancer in Khon Kaen, northeast Thailand are considered and compared with the prevalence profiles of O. viverrini. Potential impacts of the liver fluke control program particularly by mass drug administration (MDA) and public health education in the past and a recent drop of incidence of CCA are discussed in relation to primary prevention and control of this fatal bile duct cancer. © 2014 Japanese Society of Hepato-Biliary-Pancreatic Surgery.

  5. Combined hepatocellular-cholangiocarcinoma in a lesser flamingo (Phoenicopterus minor).

    PubMed

    Van Wettere, A J; Degernes, L A; Barnes, H John

    2010-08-01

    A case of combined hepatocellular-cholangiocarcinoma (CHCC) in an adult male lesser flamingo (Phoenicopterus minor) that was part of a breeding programme at a private facility is reported. Grossly, the liver was markedly enlarged with multifocal, well-circumscribed, pinpoint to 2 cm diameter pale tan nodular masses. Histologically, the hepatic parenchyma was replaced by neoplastic cells that demonstrated hepatocellular and, less frequently, biliary epithelial cell differentiation. Positive pan-cytokeratin (AE1/AE3/PCK26) immunolabelling of the neoplastic cells forming bile ducts with the scattered immunoreactivity of cells forming glandular structures within the areas of hepatocellular differentiation supported the diagnosis. No metastases were detected. CHCC is a rare neoplasm in mammals and birds. This is the first report where gross, histological, and immunohistochemical characteristics of CHCC in a bird are described, and the first report of CHCC in a lesser flamingo.

  6. Huge subcapsular hematoma caused by intrahepatic sarcomatoid cholangiocarcinoma.

    PubMed

    Jung, Gum O; Park, Dong Eun; Youn, Gi Jung

    2012-05-01

    Intrahepatic sarcomatoid cholangiocarcinomais is a very rare disease with a poor prognosis due to its biologically aggressive tumor behavior. We report a patient who presented with subcapsular hemorrhage and a rapidly growing liver mass. A 57 year-old man was admitted with severe abdominal pain. CT and MRI images showed the presence of a 10 cm-sized subcapsular hemorrhage connected with a multi-lobulated mass with hemorrhage and necrotic foci in the right liver. The patients underwent right hemihepatectomy with caudate lobectomy and lymphadenectomy. The operation findings revealed metastatic nodules to the diaphragm and omentum. Detailed histopathological analysis through immunohistochemistry confirmed the diagnosis of sarcomatoid cholangiocarcinoma with a poorly undifferentiated sarcomatous component. The patient underwent chemotherapy. To date, the patient is doing well for 8 months after initial diagnosis.

  7. Spontaneous external biliary fistula: a rare complication of cholangiocarcinoma.

    PubMed

    Song, In Do; Oh, Hyoung-Chul; Do, Jae Hyuk; Jeong, Lae Ik; Kim, Beom Jin; Kim, Jeong Wook; Kim, Jae Gyu; Chi, Kyong Choun; Kim, Mi Kyung

    2011-01-01

    A 68-year-old woman presented with yellowish discharge oozing from a fistula opening in the upper epigastric area that had persisted for one month prior to her visit. The patient had undergone a left lateral segmentectomy of the liver ten years prior for treatment of intrahepatic duct (IHD) stones. An abdominal computed tomography (CT) scan showed focal stricture and proximal dilatation of remnant IHD and a 1 cm-sized rim-enhancing lesion located under the surgical bed of the abdominal wall surrounding the dilated remnant IHD. Despite conservative management including nasobiliary drainage, no further improvement was anticipated. Partial hepatectomy and fistulectomy were performed for pathologic diagnosis and treatment of the enhancing lesion. Histopathology revealed adenocarcinoma. In this case, cholangiocarcinoma might have arisen in association with IHD stones and then developed a choledocho-cutaneous fistula as a clinical manifestation.

  8. Cell lineage tracing reveals a biliary origin of intrahepatic cholangiocarcinoma

    PubMed Central

    Guest, Rachel V; Boulter, Luke; Kendall, Timothy J; Minnis-Lyons, Sarah E; Walker, Robert; Wigmore, Stephen J; Sansom, Owen J; Forbes, Stuart J

    2014-01-01

    Intrahepatic cholangiocarcinoma (ICC) is a treatment refractory malignancy with a high mortality and an increasing incidence worldwide. Recent studies have observed that activation of Notch and AKT signalling within mature hepatocytes is able to induce the formation of tumours displaying biliary lineage markers, thereby raising the suggestion that it is hepatocytes, rather than cholangiocytes or hepatic progenitor cells that represent the cell of origin of this tumour. Here we utilise a cholangiocyte-lineage tracing system to target p53 loss to biliary epithelia and observe the appearance of labelled biliary lineage tumours in response to chronic injury. Consequent to this, up-regulation of native functional Notch signalling is observed to occur spontaneously within cholangiocytes and hepatocytes in this model as well as in human ICC. These data prove that in the context of chronic inflammation and p53 loss, frequent occurrences in human disease, biliary epithelia are a target of transformation and an origin of ICC. PMID:24310400

  9. Rapidly aggravated skeletal muscle metastases from an intrahepatic cholangiocarcinoma

    PubMed Central

    Lee, Jiyoung; Lee, Sung Wook; Han, Sang Young; Baek, Yang Hyun; Kim, Su Young; Rhyou, Hyo In

    2015-01-01

    We present a rare case of intrahepatic cholangiocarcinoma (ICC) with multiple skeletal muscle metastases. The patient was a 55-year-old Asian woman presenting with abdominal pain; abdominal and pelvic computed tomography and magnetic resonance cholangiopancreatography revealed an unresectable ICC with hepatic metastasis and metastastatic lymphadenopathy in the porto-caval area. After 3 mo of treatment with palliative radiotherapy and chemotherapy, magnetic resonance imaging of the thoracolumbar spine detected right psoas muscle and paraspinous muscle metastases. We performed an ultrasound-guided percutaneous fine-needle biopsy that confirmed a similar pattern of poorly differentiated adenocarcinoma. The patient treated with palliative chemotherapy and achieved 10 mo of survival. Here we report the first case quickly spread to multiple sites of muscle even though the three-month treatment, compare to the other cases reported muscle metastases at diagnosis. PMID:25684968

  10. Systemic therapy of cholangiocarcinoma: From chemotherapy to targeted therapies.

    PubMed

    Schweitzer, N; Vogel, A

    2015-04-01

    Cholangiocarcinomas (CCA) are rare tumors of the liver with poor prognosis. The standard of care in patients with unresectable tumors or metastatic disease is combination chemotherapy (CT) with gemcitabine and cisplatin. Targeted therapies inhibiting EGFR, VEGF, MEK and others are broadly tested in CCA but to date, the existing data from randomized and nonrandomized trials do not justify the application of small molecules outside of clinical trials. In clinical practice, many patients receive second-line CT after failure of gemcitabine/cisplatin, although there is so far no evidence to support second-line CT. This review summarizes current chemotherapy protocols and ongoing studies, including conventional chemotherapy and targeted therapies. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Outcome of Transplant-fallout Patients With Unresectable Cholangiocarcinoma

    PubMed Central

    Sio, Terence T.; Haddock, Michael G.; Novotny, Paul J.; Gores, Gregory J.; Alberts, Steven R.; Miller, Robert C.; Heimbach, Julie K.; Rosen, Charles B.

    2016-01-01

    Objectives: The aim of this was to determine survival after starting neoadjuvant therapy for patients who became ineligible for orthotopic liver transplantation (OLT). Methods and Materials: Since January 1993, 215 patients with unresectable cholangiocarcinoma began treatment with planned OLT. Treatment included external-beam radiation therapy (EBRT) with fluorouracil, bile duct brachytherapy, and postradiotherapy fluorouracil or capecitabine before OLT. Adverse findings at the staging operation, death, and other factors precluded OLT in 63 patients (29%), of whom 61 completed neoadjuvant chemoradiation. Results: By October 2012, 56 (89%) of the 63 patients unable to undergo OLT had died. Twenty-two patients (35%) became ineligible for OLT before the staging operation, 38 (60%) at the staging operation, and 3 (5%) after staging. From the date of diagnosis, median overall survival was 12.3 months. Survival was 17% at 18 months and 7% at 24 months. Median survival after fallout was 6.8 months. Median survival after the staging operation was 6 months. Two patients lived for 3.7 and 8.7 years before dying of cancer or liver failure caused by persistent biliary stricture at the site of the original cancer, respectively. Univariate analysis showed that time from diagnosis to fallout correlated with overall survival (P=0.04). Conclusions: In highly selected patients initially suitable for OLT, the mortality rate for cholangiocarcinoma was high in patients who became ineligible for OLT. Their survival, however, was comparable to expected survival for patients with locally advanced or metastatic disease treated with nontransplant therapies. The most common reason for patient fallout was adverse findings at the staging operation. PMID:24921218

  12. Synergistic effect of melatonin and ghrelin in preventing cisplatin-induced ovarian damage via regulation of FOXO3a phosphorylation and binding to the p27(Kip1) promoter in primordial follicles.

    PubMed

    Jang, Hoon; Na, Younghwa; Hong, Kwonho; Lee, Sangho; Moon, Sohyeon; Cho, Minha; Park, Miseon; Lee, Ok-Hee; Chang, Eun Mi; Lee, Dong Ryul; Ko, Jung Jae; Lee, Woo Sik; Choi, Youngsok

    2017-10-01

    Premature ovarian failure during chemotherapy is a serious problem for young women with cancer. To preserve the fertility of these patients, approaches to prevent chemotherapy-induced ovarian failure are needed. In a previous study, we reported that melatonin treatment prevents the depletion of the dormant follicle pool via repression of the simultaneous activation of dormant primordial follicles by cisplatin. However, melatonin's protective effect was only partial and thus insufficient. In this study, we found that the hormone ghrelin enhances the protective effect of melatonin against cisplatin-induced ovarian failure in mouse model. Co-administration of melatonin and ghrelin more effectively prevented cisplatin-induced follicle disruption. Simultaneous treatment with melatonin and ghrelin almost restored the number of primordial follicles and the corpus luteum in cisplatin-treated ovaries, compared with single administration. We found melatonin and ghrelin receptors on the cell membrane of premature oocytes of primordial follicles. In addition, melatonin and ghrelin co-administration inhibited the cisplatin-induced phosphorylation of PTEN and FOXO3a that induces cytoplasmic translocation of FOXO3a. Inhibition of FOXO3a phosphorylation by melatonin and ghrelin increased the binding affinity of FOXO3a for the p27(Kip1) promoter in primordial follicles. Co-administration of melatonin and ghrelin in cisplatin-treated ovaries restored the expression of p27(Kip1) , which is critical for retention of the dormant status of primordial follicles. In conclusion, these findings suggest that melatonin and ghrelin co-administration is suitable for use as a fertoprotective adjuvant therapy during cisplatin chemotherapy in young female cancer patients. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  13. Ectopic expression of H2AX protein promotes TrkA-induced cell death via modulation of TrkA tyrosine-490 phosphorylation and JNK activity upon DNA damage

    SciTech Connect

    Jung, Eun Joo; Kim, Deok Ryong

    2011-01-21

    Research highlights: {yields} We established TrkA-inducible U2OS cells stably expressing GFP-H2AX proteins. {yields} GFP-H2AX was colocalized with TrkA in the cytoplasm. {yields} {gamma}H2AX production was significantly increased upon activation of TrkA and suppressed by TrkA inhibitor or JNK inhibitor. {yields} Ectopic expression of H2AX promoted TrkA-mediated cell death through the modulation of TrkA tyrosine-490 phosphorylation and JNK activity upon DNA damage. -- Abstract: We previously reported that TrkA overexpression causes accumulation of {gamma}H2AX proteins in the cytoplasm, subsequently leading to massive cell death in U2OS cells. To further investigate how cytoplasmic H2AX is associated with TrkA-induced cell death, we established TrkA-inducible cells stably expressing GFP-tagged H2AX. We found that TrkA co-localizes with ectopically expressed GFP-H2AX proteins in the cytoplasm, especially at the juxta-nuclear membranes, which supports our previous results about a functional connection between TrkA and {gamma}H2AX in TrkA-induced cell death. {gamma}H2AX production from GFP-H2AX proteins was significantly increased when TrkA was overexpressed. Moreover, ectopic expression of H2AX activated TrkA-mediated signal pathways via up-regulation of TrkA tyrosine-490 phosphorylation. In addition, suppression of TrkA tyrosine-490 phosphorylation under a certain condition was removed by ectopic expression of H2AX, indicating a functional role of H2AX in the maintenance of TrkA activity. Indeed, TrkA-induced cell death was highly elevated by ectopic H2AX expression, and it was further accelerated by DNA damage via JNK activation. These all results suggest that cytoplasmic H2AX could play an important role in TrkA-mediated cell death by modulating TrkA upon DNA damage.

  14. Untangling the Complexity of Liver Fluke Infection and Cholangiocarcinoma in NE Thailand Through Transdisciplinary Learning.

    PubMed

    Ziegler, A D; Echaubard, P; Lee, Y T; Chuah, C J; Wilcox, B A; Grundy-Warr, C; Sithithaworn, P; Petney, T N; Laithevewat, L; Ong, X; Andrews, R H; Ismail, T; Sripa, B; Khuntikeo, N; Poonpon, K; Tungtang, P; Tuamsuk, K

    2016-06-01

    This study demonstrates how a transdisciplinary learning approach provided new insights for explaining persistent Opisthorchis viverrini infection in northern Thailand, as well as elucidating problems of focusing solely on the parasite as a means of addressing high prevalence of cholangiocarcinoma. Researchers from diverse backgrounds collaborated to design an investigative homestay program for 72 Singaporean and Thai university students in five northeast Thai villages. The students explored how liver fluke infection and potential cholangiocarcinoma development are influenced by local landscape dynamics, aquatic ecology, livelihoods, food culture and health education. Qualitative fieldwork was guided daily by the researchers in a collaborative, co-learning process that led to viewing this health issue as a complex system, influenced by interlinked multidimensional factors. Our transdisciplinary experience has led us to believe that an incomplete understanding of these linkages may reduce the efficacy of interventions. Further, viewing liver fluke infection and cholangiocarcinoma as the same issue is inadvisable. Although O. viverrini infection is an established risk factor for the development of cholangiocarcinoma, multiple factors are known to influence the likelihood of acquiring either. Understanding the importance of the current livelihood transition, landscape modification and the resulting mismatch between local cultures and new socio-ecological settings on cholangiocarcinoma initiation and liver fluke transmission is of critical importance as it may help readjust our view of the respective role of O. viverrini and other socioeconomic risk factors in cholangiocarcinoma etiology and refine intervention strategies. As demonstrated in this study, transdisciplinary approaches have the potential to yield more nuanced perspectives to complex diseases than research that focuses on specific aspects of their epidemiology. They may therefore be valuable when designing

  15. Prognostic significance of peroxiredoxin 1 and ezrin-radixin-moesin-binding phosphoprotein 50 in cholangiocarcinoma.

    PubMed

    Yonglitthipagon, Ponlapat; Pairojkul, Chawalit; Chamgramol, Yaovalux; Loukas, Alex; Mulvenna, Jason; Bethony, Jeffrey; Bhudhisawasdi, Vajarabhongsa; Sripa, Banchob

    2012-10-01

    We performed a comparative proteomic analysis of protein expression profiles in 4 cholangiocarcinoma cell lines: K100, M156, M213, and M139. The H69 biliary cell line was used as a control. Peroxiredoxin 1 and ezrin-radixin-moesin-binding phosphoprotein 50 were selected for further validation by immunohistochemistry using a cholangiocarcinoma tissue microarray (n = 301) to assess their prognostic value in this cancer. Both peroxiredoxin 1 and ezrin-radixin-moesin-binding phosphoprotein 50 were overexpressed in cholangiocarcinoma tissues compared with normal liver tissues. Of the 301 cholangiocarcinoma cases, overexpression of peroxiredoxin 1 in 103 (34.3%) was associated with an age-related effect in young patients (P = .011) and the absence of cholangiocarcinoma in lymphatic vessels and perineural tissues (P = .004 and P = .037, respectively). Expression of radixin-moesin-binding phosphoprotein 50 correlated with histopathologic type, with 180 (59.8%) of moderately or poorly differentiated tumors (P = .039) being higher, and was associated with the presence of cholangiocarcinoma in lymphatic and vascular vessels (P < .001 and P < .001, respectively). The high expression of radixin-moesin-binding phosphoprotein 50 and the low expression of peroxiredoxin 1 correlated with reduced survival by univariate analysis (P = .017 and P = .048, respectively). Moreover, the impact of peroxiredoxin 1 and radixin-moesin-binding phosphoprotein 50 expression on patient survival was an independent predictor in multivariate analyses (P = .004 and P = .025, respectively). Therefore, altered expression of peroxiredoxin 1 and radixin-moesin-binding phosphoprotein 50 may be used as prognostic markers in cholangiocarcinoma.

  16. Protein phosphatase Mg2+/Mn2+ dependent 1F promotes smoking-induced breast cancer by inactivating phosphorylated-p53-induced signals

    PubMed Central

    Tu, Shih-Hsin; Lin, Yin-Ching; Huang, Chi-Cheng; Yang, Po-Sheng; Chang, Hui-Wen; Chang, Chien-Hsi; Wu, Chih-Hsiung; Chen, Li-Ching; Ho, Yuan-Soon

    2016-01-01

    We previously demonstrated that the activation of α9-nicotinic acetylcholine receptor (α9-nAchR) signaling by smoking promotes breast cancer formation. To investigate the downstream signaling molecules involved in α9-nAChR-induced breast tumorigenesis, we used real-time polymerase chain reactions and Western blotting to assess expression of protein phosphatase Mg2+/Mn2+ dependent 1F (PPM1F), a Ser/Thr protein phosphatase, in human breast cancer samples (n=167). Additionally, stable PPM1F-knockdown and -overexpressing cell lines were established to evaluate the function of PPM1F. The phosphatase activity of PPM1F in nicotine-treated cells was assessed through Western blotting, confocal microscopy, and fluorescence resonance energy transfer. Higher levels of PPM1F were detected in the breast cancer tissues of heavy smokers (n=7, 12.8-fold) greater than of non-smokers (n= 28, 6.3-fold) (**p=0.01). In vitro, nicotine induced PPM1F expression, whereas α9-nAChR knockdown reduced the protein expression of PPM1F. A series of biochemical experiments using nicotine-treated cells suggested that the dephosphorylation of p53 (Ser-20) and BAX (Ser-184) by PPM1F is a critical posttranslational modification, as observed in breast cancer patients who were heavy smokers. These observations indicate that PPM1F may be a mediator downstream of α9-nAChR that activates smoking-induced carcinogenic signals. Thus, PPM1F expression could be used for prognostic diagnosis or inhibited for cancer prevention and therapy. PMID:27769050

  17. Fluorogenic 2D Peptidosheet Unravels CD47 as a Potential Biomarker for Profiling Hepatocellular Carcinoma and Cholangiocarcinoma Tissues.

    PubMed

    Ma, Yun-Han; Dou, Wei-Tao; Pan, Yu-Fei; Dong, Li-Wei; Tan, Ye-Xiong; He, Xiao-Peng; Tian, He; Wang, Hong-Yang

    2017-02-01

    A 2D peptidosheet unravels CD47 as a potential biomarker to image hepatocarcinoma and cholangiocarcinoma cells and tissues. Supramolecular assembly between water-soluble 2D MoS2 and a peptide probe produces the 2D peptidosheet suited for the profiling of hepatocarcinoma and cholangiocarcinoma tissues over healthy tissues on clinical specimens.

  18. Biological effects of RNAi targeted inhibiting Tiam1 gene expression on cholangiocarcinoma cells.

    PubMed

    Cheng, Wei; Liu, Yaling; Zuo, Zhi; Yin, Xinmin; Jiang, Bo; Chen, Daojin; Peng, Chuang; Yang, Jianhui

    2015-01-01

    To investigate the characteristics of Tiam1 gene expression in human cholangiocarcinoma tissues and benign bile duct tissues, and to analyze the correlations between Tiam1 gene expression and the degree of tumor differentiation, invasive and metastatic abilities. To explore the effect of targeted inhibiting Tiam1 gene expression on proliferation and migration activity of human cholangiocarcinoma cells. Expression of Tiam1 in 83 cases of cholangiocarcinoma tissues and 25 cases of benign bile tissues was detected using immunohistochemistry. The clinical data of patients with cholangiocarcinoma were collected. The correlations between Tiam1 gene expression and the clinicopathologic features in patients with cholangiocarcinoma were analyzed. The human cholangiocarcinoma RBE cells were divided into 3 groups. Cells in experimental group and control group were respectively transfected with Tiam1 shRNA lentiviral vectors and negative shRNA lentiviral control vectors. Cells in blank group received no treatment. Real-time PCR endogenesis was used to verify Tiam1 gene expression. Cell cycle experiments and MTT assay were used to measure cell proliferation activity. Transwell test was used to detect cell migration activity. The negative rate Tiam1 protein expression in cholangiocarcinoma tissues was significantly higher than that in benign bile tissues (P<0.001). Tiam1 protein expression in cholangiocarcinoma tissues had correlations with cholangiocarcinoma differentiation degree, TNM stage and lymph node metastasis (P<0.05), and had no significant correlations with gender, age and distant metastasis (P>0.05). Real-time PCR detection indicated that Tiam1 expression of experimental group was significantly lower than that in control group and blank group (P<0.05), demonstrating that Tiam1 shRNA was effective on Tiam1 gene silencing in RBE cells. Cell cycle experiment showed that the percentage of S phase in cell cycle in experimental group was lower than that in control group

  19. Biological effects of RNAi targeted inhibiting Tiam1 gene expression on cholangiocarcinoma cells

    PubMed Central

    Cheng, Wei; Liu, Yaling; Zuo, Zhi; Yin, Xinmin; Jiang, Bo; Chen, Daojin; Peng, Chuang; Yang, Jianhui

    2015-01-01

    Objective: To investigate the characteristics of Tiam1 gene expression in human cholangiocarcinoma tissues and benign bile duct tissues, and to analyze the correlations between Tiam1 gene expression and the degree of tumor differentiation, invasive and metastatic abilities. To explore the effect of targeted inhibiting Tiam1 gene expression on proliferation and migration activity of human cholangiocarcinoma cells. Methods: Expression of Tiam1 in 83 cases of cholangiocarcinoma tissues and 25 cases of benign bile tissues was detected using immunohistochemistry. The clinical data of patients with cholangiocarcinoma were collected. The correlations between Tiam1 gene expression and the clinicopathologic features in patients with cholangiocarcinoma were analyzed. The human cholangiocarcinoma RBE cells were divided into 3 groups. Cells in experimental group and control group were respectively transfected with Tiam1 shRNA lentiviral vectors and negative shRNA lentiviral control vectors. Cells in blank group received no treatment. Real-time PCR endogenesis was used to verify Tiam1 gene expression. Cell cycle experiments and MTT assay were used to measure cell proliferation activity. Transwell test was used to detect cell migration activity. Results: The negative rate Tiam1 protein expression in cholangiocarcinoma tissues was significantly higher than that in benign bile tissues (P<0.001). Tiam1 protein expression in cholangiocarcinoma tissues had correlations with cholangiocarcinoma differentiation degree, TNM stage and lymph node metastasis (P<0.05), and had no significant correlations with gender, age and distant metastasis (P>0.05). Real-time PCR detection indicated that Tiam1 expression of experimental group was significantly lower than that in control group and blank group (P<0.05), demonstrating that Tiam1 shRNA was effective on Tiam1 gene silencing in RBE cells. Cell cycle experiment showed that the percentage of S phase in cell cycle in experimental group was lower

  20. Free radicals enzymatically triggered by Clonorchis sinensis excretory-secretory products cause NF-κB-mediated inflammation in human cholangiocarcinoma cells.

    PubMed

    Nam, Joo-Hyun; Moon, Ju Hyun; Kim, In Ki; Lee, Myoung-Ro; Hong, Sung-Jong; Ahn, Joong Ho; Chung, Jong Woo; Pak, Jhang Ho

    2012-01-01

    Chronic clonorchiasis, caused by direct and continuous contact with Clonorchis sinensis worms and their excretory-secretory products, is associated with hepatobiliary damage, inflammation, periductal fibrosis and even development of cholangiocarcinoma. Our previous report revealed that intracellular reactive oxygen species were generated in C. sinensis excretory-secretory product-treated human cholangiocarcinoma cells; however, their endogenous sources and pathophysiological roles in host cells were not determined. In the present study, we found that treatment of human cholangiocarcinoma cells with excretory-secretory products triggered increases in free radicals via a time-dependent activation of NADPH oxidase, xanthine oxidase and inducible nitric oxide synthase. This increase in free radicals substantially promoted the degradation of cytosolic IκB-α, nuclear translocation of nuclear factor-κB subunits (RelA and p50), and increased κB consensus DNA-binding activity. Excretory-secretory product-induced nuclear factor-κB activation was markedly attenuated by preincubation with specific inhibitors of each free radical-producing enzyme or the antioxidant, N-acetylcysteine. Moreover, excretory-secretory products induced an increase in the mRNA and protein expression of the proinflammatory cytokines, IL-1β and IL-6, in an nuclear factor-κB-dependent manner, indicating that enzymatic production of free radicals in ESP-treated cells participates in nuclear factor-κB-mediated inflammation. These findings provide new insights into the pathophysiological role of C. sinensis excretory-secretory products in host chronic inflammatory processes, which are initial events in hepatobiliary diseases.

  1. Metformin Exerts Antiproliferative and Anti-metastatic Effects Against Cholangiocarcinoma Cells by Targeting STAT3 and NF-ĸB.

    PubMed

    Saengboonmee, Charupong; Seubwai, Wunchana; Cha'on, Ubon; Sawanyawisuth, Kanlayanee; Wongkham, Sopit; Wongkham, Chaisiri

    2017-01-01

    Cholangiocarcinoma (CCA) is an aggressive cancer for which standard treatments are still ineffective. This study demonstrated the antiproliferative and anti-metastatic activity of metformin, an anti-diabetic drug, in CCA cells. Cell proliferation, migration/invasion and anoikis resistance were determined. The underlying mechanisms were identified using western blotting and immunocytofluorescence. Metformin significantly suppressed proliferation of CCA cells in a dose- and time-dependent manner, regardless of glucose present in the medium. A low dose of metformin significantly increased anoikis and inhibited migration/ invasion of CCA cells that was in concert with the decrease of vimentin, matrix metalloproteinase (MMP)-2 and -7. Activation of 5' adenosine monophosphate-activated protein kinase (AMPK) by phosphorylation together with suppression of nuclear translocation of signal transducer and activator of transcription 3 (STAT3) and nuclear factor-kappa B (NF-ĸB) were the underlying mechanisms for these effects. Metformin is a potent antiproliferative and anti-metastatic agent against human CCA cells. These findings encourage the repurposing of metformin in clinical trials to improve CCA treatment. Copyright© 2017 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

  2. Quercetin and EGCG exhibit chemopreventive effects in cholangiocarcinoma cells via suppression of JAK/STAT signaling pathway.

    PubMed

    Senggunprai, Laddawan; Kukongviriyapan, Veerapol; Prawan, Auemduan; Kukongviriyapan, Upa

    2014-06-01

    Quercetin and epigallocatechin-3-gallate (EGCG) are dietary phytochemicals with antiinflammatory and antitumor effects. In the present study, we examined the effects of these two compounds on Janus-like kinase (JAK)/signal transduction and transcription (STAT) pathway of cholangiocarcinoma (CCA) cells, because CCA is one of the aggressive cancers with very poor prognosis and JAK/STAT pathway is critically important in inflammation and carcinogenesis. The results showed that the JAK/STAT pathway activation by proinflammatory cytokine interleukin-6 and interferon-γ in CCA cells was suppressed by pretreatment with quercetin and EGCG, evidently by a decrease of the elevated phosphorylated-STAT1 and STAT3 proteins in a dose-dependent manner. The cytokine-mediated up-regulation of inducible nitric oxide synthase (iNOS) and intercellular adhesion molecule-1 (ICAM-1) via JAK/STAT cascade was abolished by both quercetin and EGCG pretreatment. Moreover, these flavonoids also could inhibit growth and cytokine-induced migration of CCA cells. Pretreatment with specific JAK inhibitors, AG490 and piceatannol, abolished cytokine-induced iNOS and ICAM-1 expression. These results demonstrate beneficial effects of quercetin and EGCG in the suppression of JAK/STAT cascade of CCA cells. Quercetin and EGCG would be potentially useful as cancer chemopreventive agents against CCA. Copyright © 2013 John Wiley & Sons, Ltd.

  3. Macrophage stimulating protein variation enhances the risk of sporadic extrahepatic cholangiocarcinoma.

    PubMed

    Krawczyk, Marcin; Höblinger, Aksana; Mihalache, Florentina; Grünhage, Frank; Acalovschi, Monica; Lammert, Frank; Zimmer, Vincent

    2013-07-01

    Primary sclerosing cholangitis confers risk of cholangiocarcinoma. Here, we assessed the primary sclerosing cholangitis-associated variant rs3197999 in the MST1 gene, coding for RON receptor tyrosine kinase ligand macrophage stimulating protein, in a large European cholangiocarcinoma cohort. 223 cholangiocarcinoma patients including three primary sclerosing cholangitis individuals and 355 cancer- and primary sclerosing cholangitis-free controls were genotyped for MST1 rs3197999. The cancer group departed from Hardy-Weinberg equilibrium (p = 0.022) and exhibited a trend for rs3197999 [A] overrepresentation (31% vs. 26%: p = 0.10). Homozygous rs3197999 [AA] carrier status significantly increased overall (OR = 1.97; p = 0.023) and primary sclerosing cholangitis-unrelated biliary tract cancer risk (OR = 1.84; p = 0.044), relative to homozygous common allele carriers. The association was most pronounced in patients with extrahepatic tumours. This finding was robust to multivariate analysis (p < 0.05), validating the [AA] genotype as an independent cholangiocarcinoma risk factor. These results suggest that the [AA] genotype of the common MST1 variant rs3197999 enhances genetic risk of sporadic extrahepatic cholangiocarcinoma irrespective of primary sclerosing cholangitis status, presumably by modulating inflammatory responses and/or altered MSP/RON signalling. Copyright © 2013 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.

  4. Cholangiocarcinoma and malignant bile duct obstruction: A review of last decades advances in therapeutic endoscopy

    PubMed Central

    Bertani, Helga; Frazzoni, Marzio; Mangiafico, Santi; Caruso, Angelo; Manno, Mauro; Mirante, Vincenzo Giorgio; Pigò, Flavia; Barbera, Carmelo; Manta, Raffaele; Conigliaro, Rita

    2015-01-01

    In the last decades many advances have been achieved in endoscopy, in the diagnosis and therapy of cholangiocarcinoma, however blood test, magnetic resonance imaging, computed tomography scan may fail to detect neoplastic disease at early stage, thus the diagnosis of cholangiocarcinoma is achieved usually at unresectable stage. In the last decades the role of endoscopy has moved from a diagnostic role to an invaluable therapeutic tool for patients affected by malignant bile duct obstruction. One of the major issues for cholangiocarcinoma is bile ducts occlusion, leading to jaundice, cholangitis and hepatic failure. Currently, endoscopy has a key role in the work up of cholangiocarcinoma, both in patients amenable to surgical intervention as well as in those unfit for surgery or not amenable to immediate surgical curative resection owing to locally advanced or advanced disease, with palliative intention. Endoscopy allows successful biliary drainage and stenting in more than 90% of patients with malignant bile duct obstruction, and allows rapid reduction of jaundice decreasing the risk of biliary sepsis. When biliary drainage and stenting cannot be achieved with endoscopy alone, endoscopic ultrasound-guided biliary drainage represents an effective alternative method affording successful biliary drainage in more than 80% of cases. The purpose of this review is to focus on the currently available endoscopic management options in patients with cholangiocarcinoma. PMID:26078827

  5. Mass spectrometry-based proteomic analysis of formalin-fixed paraffin-embedded extrahepatic cholangiocarcinoma.

    PubMed

    Maeda, Shimpei; Morikawa, Takanori; Takadate, Tatsuyuki; Suzuki, Takashi; Minowa, Takashi; Hanagata, Nobutaka; Onogawa, Tohru; Motoi, Fuyuhiko; Nishimura, Toshihide; Unno, Michiaki

    2015-09-01

    Extrahepatic cholangiocarcinoma is very difficult to diagnose at an early stage, and has a poor prognosis. Novel markers for diagnosis and optimal treatment selection are needed. However, there has been very limited data on the proteome profile of extrahepatic cholangiocarcinoma. This study was designed to unravel the proteome profile of this disease and to identify overexpressed proteins using mass spectrometry-based proteomic approaches. We analyzed a discovery set of formalin-fixed paraffin-embedded tissues of 14 extrahepatic cholangiocarcinomas using shotgun mass spectrometry, and compared proteome profiles with those of seven controls. Then, selected candidates were verified by quantitative analysis using scheduled selected reaction monitoring-based mass spectrometry. Furthermore, immunohistochemical staining used a validation set of 165 cases. In total, 1,992 proteins were identified and 136 proteins were overexpressed. Verification of 58 selected proteins by quantitative analysis revealed 11 overexpressed proteins. Immunohistochemical validation for 10 proteins showed positive rates of S100P (84%), CEAM5 (75%), MUC5A (62%), OLFM4 (60%), OAT (42%), CAD17 (41%), FABPL (38%), AOFA (30%), K1C20 (25%) and CPSM (22%) in extrahepatic cholangiocarcinomas, which were rarely positive in controls. We identified 10 proteins associated with extrahepatic cholangiocarcinoma using proteomic approaches. These proteins are potential targets for future diagnostic biomarkers and therapy. © 2015 Japanese Society of Hepato-Biliary-Pancreatic Surgery.

  6. Cholangiocarcinoma in Italy: A national survey on clinical characteristics, diagnostic modalities and treatment. Results from the "Cholangiocarcinoma" committee of the Italian Association for the Study of Liver disease.

    PubMed

    Alvaro, Domenico; Bragazzi, Maria Consiglia; Benedetti, Antonio; Fabris, Luca; Fava, Giammarco; Invernizzi, Pietro; Marzioni, Marco; Nuzzo, Gennaro; Strazzabosco, Mario; Stroffolini, Tommaso

    2011-01-01

    Very few studies assessed cholangiocarcinoma clinical characteristics. To evaluate the clinical characteristics of intra-hepatic (IH) and extra-hepatic (EH)-CCA. We performed a national survey based on a questionnaire. 218 cholangiocarcinomas were observed (47% EH-CCA, 53% IH-CCA) with an age at the diagnosis higher for EH-CCA. Coexistence of cirrhosis or viral cirrhosis was more frequent in IH-CCA than EH-CCA. An incidental asymptomatic presentation occurred in 28% of IH-CCA vs 4% EH-CCA whilst, 74% EH-CCA vs 28% IH-CCA presented with jaundice. 91% of IH-CCA presented as a single intra-hepatic mass, whilst 50% of EH-CCA was peri-hilar. In the diagnostic work-up, 70% of all cholangiocarcinoma cases received at least 3 different imaging procedures. Tissue-proven diagnosis was obtained in 80% cholangiocarcinoma. Open surgery with curative intent was performed in 45% of IH-CCA and 29% EH-CCA. 18% IH-CCA vs 4% EH-CCA did not received treatment. In Italy IH-CCA is managed as frequently as EH-CCA. In comparison to EH-CCA, IH-CCA occurs at younger age and is more frequently associated with cirrhosis and with an incidental asymptomatic presentation. In contrast, most EH-CCAs are jaundiced at the diagnosis. Cholangiocarcinoma diagnostic management is cost- and time-consuming with curative surgical treatment applicable more frequently in IH-CCA. Copyright © 2010 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.

  7. Predictors of intrahepatic cholangiocarcinoma in cirrhotic patients scanned by gadobenate dimeglumine-enhanced magnetic resonance imaging: diagnostic accuracy and confidence.

    PubMed

    Quaia, Emilio; Angileri, Roberta; Arban, Federica; Gennari, Antonio Giulio; Cova, Maria Assunta

    2015-01-01

    To identify predictors of intrahepatic cholangiocarcinoma in cirrhotic patients scanned by gadobenate dimeglumine (Gd-BOPTA)-enhanced magnetic resonance (MR) imaging. Fifty cirrhotic patients with 120 nodules, including 10 mass-forming intrahepatic cholangiocarcinomas and two combined hepatocellular carcinoma-cholangiocarcinomas, were scanned by Gd-BOPTA-enhanced MR imaging. T1 hypointensity [odds ratio (OR), 20.12], peripheral hyperintense rim at hepatic arterial phase (OR, 13.5), and iso-hyperintensity at hepatobiliary phase (OR 21.32) were found to be independent predictors of intrahepatic cholangiocarcinoma. T1 hypointensity, peripheral hyperintense rim at hepatic arterial phase, and iso-hyperintensity at hepatobiliary phase are independent predictors of intrahepatic cholangiocarcinoma diagnosis in patients with liver cirrhosis. Copyright © 2015 Elsevier Inc. All rights reserved.

  8. The dual effects of delta(9)-tetrahydrocannabinol on cholangiocarcinoma cells: anti-invasion activity at low concentration and apoptosis induction at high concentration.

    PubMed

    Leelawat, Surang; Leelawat, Kawin; Narong, Siriluck; Matangkasombut, Oraphan

    2010-05-01

    Currently, only gemcitabine plus platinum demonstrates the considerable activity for cholangiocarcinoma. The anticancer effect of Delta (9)-tetrahydrocannabinol (THC), the principal active component of cannabinoids has been demonstrated in various kinds of cancers. We therefore evaluate the antitumor effects of THC on cholangiocarcinoma cells. Both cholangiocarcinoma cell lines and surgical specimens from cholangiocarcinoma patients expressed cannabinoid receptors. THC inhibited cell proliferation, migration and invasion, and induced cell apoptosis. THC also decreased actin polymerization and reduced tumor cell survival in anoikis assay. pMEK1/2 and pAkt demonstrated the lower extent than untreated cells. Consequently, THC is potentially used to retard cholangiocarcinoma cell growth and metastasis.

  9. [Phosphorylation of tau protein].

    PubMed

    Uchida, T; Ishiguro, K

    1990-05-01

    In aged human brain and particularly in Alzheimer's disease brain, paired helical filaments (PHFs) accumulate in the neuronal cell. Recently, it has been found that the highly phosphorylated tau protein, one of the microtubule-associated proteins (MAPs), is a component of PHF. The authors attempted to clarify the mechanism underlying the accumulation of PHF from the following two aspects; 1) What is the mechanism of phosphorylation of tau protein? 2) Is the highly phosphorylated tau protein capable of forming PHFs? From rat or bovine microtubule proteins we partially purified and characterized a novel protein kinase that specifically phosphorylated tau and MAP2 among many proteins in the brain extract, and which formed a PHF epitope on the phosphorylated human tau. This enzyme was one of the protein serine/threonine kinases and was independent of known second messengers. The phosphorylation of tau by this enzyme was stimulated by tubulin under the condition of microtubule formation, suggesting that the phosphorylation of tau could occur concomitantly with microtubule formation in the brain. Since this kinase was usually bound to tau but not directly to tubulin, the enzyme was associated with microtubules through tau. From these properties related to tau, this kinase is designated as tau protein kinase. The tau that been phosphorylated with this kinase using [gamma-32P]ATP as a phosphate donor, was digested by endoprotinase Lys-C to produce three labeled fragments, K1, K2 and K3. These three fragments were sequenced and the phosphorylation sites on tau by this kinase were identified. The K2 fragment overlapped with the tau-1 site known to be one of the phosphorylation site in PHF. This result strengthens the possibility that tau protein phosphorylated by tau protein kinase is incorporated into PHF. Tubulin binding sites on tau were located between K1 and K3 fragments, while K2 fragment was located in the neighboring to N-terminus of K1. No phosphorylated sites were

  10. Examining site-specific GPCR phosphorylation.

    PubMed

    Butcher, Adrian J; Tobin, Andrew B; Kong, Kok Choi

    2011-01-01

    Phosphorylation of G protein-coupled receptors (GPCRs) is one of the most prominent post-translation modifications mediated by agonist stimulation. This process has been shown to result not only in receptor desensitisation but also, via the recruitment of arrestin adaptor proteins, to promote receptor coupling to numerous signalling pathways. Furthermore, there is now a growing body of evidence suggesting that GPCRs may employ phosphorylation as a mechanism to regulate their cell-type-specific signalling, hence generating tissue-specific functions. These advances have resulted partly from improved methods used in the determination of phospho-acceptor sites on GPCRs and improved analysis of the consequences of phosphorylation. This chapter aims to describe the methods used in our laboratory for the investigation of site-specific phosphorylation of the M₃-muscarinic receptor. These methods could easily be applied in the study of other receptors.

  11. A case of distal extrahepatic cholangiocarcinoma with two positive resection margins

    PubMed Central

    Warner, Wayne A.; Ramcharan, Wesley; Harnanan, Dave; Umakanthan, Srikanth; Maharaj, Ravi

    2016-01-01

    Cholangiocarcinoma is an uncommon primary malignancy of the biliary tract that is challenging to diagnose and treat effectively due to its relatively silent and late clinical presentation. The present study reports a case of a 60-year-old male with distal extrahepatic cholangiocarcinoma with a 3-week history of painless obstructive jaundice symptoms and subjective weight loss. Imaging revealed an obstructing lesion in the common bile duct, just distal to the entrance of the cystic duct. Pathology revealed moderately differentiated cholangiocarcinoma with two positive proximal resection margins. The two positive resection margins presented a challenge during surgery and points to an urgent need for further studies to better illuminate diagnostic and therapeutic options for patients with similar clinicopathological presentation. PMID:27895774

  12. Cholangiocarcinoma cell line TK may be useful for the pharmacokinetic study of the chemotherapeutic agent gemcitabine.

    PubMed

    Kamada, Minori; Akiyoshi, Kohei; Akiyama, Nobutake; Funamizu, Naotake; Watanabe, Michiko; Fujioka, Kouki; Ikeda, Kei-Ichi; Manome, Yoshinobu

    2014-08-01

    Cholangiocarcinoma is a disease with a poor prognosis. A human cholangiocarcinoma cell line, TK, was previously established to enable further understanding of the disease. We conducted this investigation to determine whether or not the TK line is useful for pharmacokinetic study of the chemotherapeutic agent gemcitabine (GEM). Along with the BXPC3 human pancreatic adenocarcinoma cell line, the sensitivity to and effects on the TK cell line of GEM were compared. The influence of deoxycytidine kinase (dCK) transduction was also comparatively investigated. The effects of GEM in terms of drug sensitivity of the TK cell line, cell cycle and levels of transcripts of key enzymes were comparable to the BXPC3 cell line. Responses to the drug were similar in both cell lines. In contrast to pancreatic carcinoma, cell lines for research on cholangiocarcinoma have been limited. This study suggests the application of the TK cell line to the pharmacokinetic study of the chemosensitization of therapeutic drugs, such as GEM.

  13. The impact of changed strategies for patients with cholangiocarcinoma in this millenium.

    PubMed

    Lindnér, Per; Rizell, Magnus; Hafström, Lo

    2015-01-01

    Background. Cholangiocarcinoma is a cancer with a poor prognosis. In this millennium there are new diagnostic and therapeutic strategies for these patients. Aim. The aim of this study was to find if these changes influenced survival of individuals with proximal cholangiocarcinoma. Material. 627 individuals with a diagnosis of cholangiocarcinoma (not including distal common duct cancer) during the period from 2000 to 2011 were registered in Sweden's Western Region. The material was divided into three consecutive time periods. Results. The overall survival curves for individuals with cholangiocarcinoma improved over the three time periods (n = 627) (P = 0.0013). Median survival increased from 2.6 months in the first period (2000-2003) to 3.6 months in the final four years (2008-2011). Patients with perihilar cholangiocarcinoma (PHC) had longer median survival than those with intrahepatic cholangiocarcinoma (IHC): 6.8 versus 3.2 months (P = 0.0003). An improvement in the survival curves over time was seen for those with IHC (P = 0.034) but not for patients with PHC (P = 0.38). Nine percent of the patients with IHC had potential curative surgical therapy. The three-year survival rate after liver resection for patients with IHC was 35% and 60% after liver transplantation. Among patients with PHC, 15.3% had potential curative bile duct resection with a concomitant liver resection and 6.1% bile duct resection alone. The three-year survival rate for these two groups was 32% and 20%, respectively. Conclusion. Overall survival for individuals with PHC was better than for those with IHC. Over time survival in IHC patients improved but not in those with PHC.

  14. PI 3-kinase-dependent phosphorylation of Plk1–Ser99 promotes association with 14-3-3γ and is required for metaphase–anaphase transition

    PubMed Central

    Kasahara, Kousuke; Goto, Hidemasa; Izawa, Ichiro; Kiyono, Tohru; Watanabe, Nobumoto; Elowe, Sabine; Nigg, Erich A; Inagaki, Masaki

    2013-01-01

    Polo-like kinase 1 (Plk1) controls multiple aspects of mitosis and is activated through its phosphorylation at Thr210. Here we identify Ser99 on Plk1 as a novel mitosis-specific phosphorylation site, which operates independently of Plk1–Thr210 phosphorylation. Plk1–Ser99 phosphorylation creates a docking site for 14-3-3γ, and this interaction stimulates the catalytic activity of Plk1. Knockdown of 14-3-3γ or replacement of wild-type (WT) Plk1 by a Ser99-phospho-blocking mutant leads to a prometaphase/metaphase-like arrest due to the activation of the spindle assembly checkpoint. Inhibition of phosphatidylinositol 3-kinase (PI3K) and Akt significantly reduces the level of Plk1–Ser99 phosphorylation and delays metaphase to anaphase transition. Plk1–Ser99 phosphorylation requires not only Akt activity but also protein(s) associated with Plk1 in a mitosis-specific manner. Therefore, mitotic Plk1 activity is regulated not only by Plk1–Thr210 phosphorylation, but also by Plk1 binding to 14-3-3γ following Plk1–Ser99 phosphorylation downstream of the PI3K–Akt signalling pathway. This novel Plk1 activation pathway controls proper progression from metaphase to anaphase. PMID:23695676

  15. Potential targeted therapy for liver fluke associated cholangiocarcinoma.

    PubMed

    Vaeteewoottacharn, Kulthida; Seubwai, Wunchana; Bhudhisawasdi, Vajarabhongsa; Okada, Seiji; Wongkham, Sopit

    2014-06-01

    Biliary tree cancer or cholangiocarcinoma (CCA) is an unusual subtype of liver cancer with exceptionally poor prognosis. Lack of specific symptoms and availability of early diagnostic markers account for late diagnosis of CCA. Surgical treatment is a gold standard choice but few patients are candidates and local recurrence after surgery is high. Benefit of systemic chemotherapy is limited; hence, better treatment options are required. The differences in etiology, anatomical positions and pathology make it difficult to generalize all CCA subtypes for a single treatment regimen. Herein, we review the uniqueness of molecular profiling identified by multiple approaches, for example, serial analysis of gene expression, exome sequencing, transcriptomics/proteomics profiles, protein kinase profile, etc., that provide the opportunity for treatment of liver fluke-associated CCA. Anti-inflammatory, immunomodulator/immunosuppressor, epidermal growth factor receptor or platelet-derived growth factor receptor inhibitors, multi-targeted tyrosine kinase inhibitor, IL6 antagonist, nuclear factor-κB inhibitor, histone modulator, proteasome inhibitor as well as specific inhibitors suggested from various study approaches, such as MetAP2 inhibitor, 1,25(OH)2 D3 and cyclosporine A are suggested in this review for the treatments of this specific CCA subtype. This might provide an alternative treatment option for CCA patients; however, clinical trials in this specific CCA group are required. © 2014 Japanese Society of Hepato-Biliary-Pancreatic Surgery.

  16. Tumor-related gene changes in immunosuppressive Syrian hamster cholangiocarcinoma.

    PubMed

    Juasook, Amornrat; Aukkanimart, Ratchadawan; Boonmars, Thidarut; Sudsarn, Pakkayanee; Wonkchalee, Nadchanan; Laummaunwai, Porntip; Sriraj, Pranee

    2013-10-01

    The results of a previous study demonstrated that prednisolone enhanced cholangiocarcinogenesis. Therefore, to clarify molecular changes during immunosuppressive cholangiocarcinogenesis, Syrian hamsters were divided into 8 groups: uninfected controls; immunosuppressed Syrian hamsters using prednisolone (P); normal Syrian hamsters administered N-nitrosodimethylamine (ND); immunosuppressed Syrian hamsters administered N-nitrosodimethylamine (NDis); normal Syrian hamsters infected with Opisthorchis viverrini (OV); immunosuppressed Syrian hamsters infected with O. viverrini (OVis); normal Syrian hamsters infected with O. viverrini and administered N-nitrosodimethylamine (CCA); and immunosuppressed Syrian hamsters infected with O. viverrini and administered N-nitrosodimethylamine (CCAis). Syrian hamster livers were used for analysis of tumor-related gene expression and immunohistochemistry through cytokeratin 19 (CK19) and proliferating cell nuclear antigen (PCNA) staining. The tumor-related gene expression results show that CCAis groups at all time points exhibited upregulation of COX-2, IL-6, SOD1, CAT and iNOS and downregulation of p53, which correlated with the predominant expression of CK19 and PCNA in liver tissue. These results suggest that prednisolone enhances cholangiocarcinoma development, which was confirmed by molecular changes.

  17. Opisthorchiasis and Opisthorchis-associated cholangiocarcinoma in Thailand and Laos

    PubMed Central

    Sripa, Banchob; Bethony, Jeffrey M.; Sithithaworn, Paiboon; Kaewkes, Sasithorn; Mairiang, Eimorn; Loukas, Alex; Mulvenna, Jason; Laha, Thewarach; Hotez, Peter J.; Brindley, Paul J.

    2010-01-01

    Liver fluke infection caused by Opisthorchis viverrini is a major public health problem in Thailand and the Lao People’s Democratic Republic (Lao PDR; Laos). Currently, more than 600 million people are at risk of infection with these fish-borne trematodes and/or their close relatives. Opisthorchiasis has been studied extensively in Thailand, where about 8 million people are infected with the liver fluke. Here we review the pathogenesis, control and re-emergence of O. viverrini infection, in particular in Thailand and, to a lesser extent in Lao PDR given the contiguous geographical range of O. viverrini through these two regions. We also review the association of O. viverrini infection and cholangiocarcinoma, bile duct cancer, and highlight new findings on pathogenesis of liver fluke induced cholangiocarcinogenesis. Last, we comment on national control strategies in Thailand for the control of O. viverrini infection aimed at reduction in the prevalence of O. viverrini-associated liver cancer in the longer term. PMID:20655862

  18. The search for novel diagnostic and prognostic biomarkers in cholangiocarcinoma.

    PubMed

    Macias, Rocio I R; Banales, Jesus M; Sangro, Bruno; Muntané, Jordi; Avila, Matias A; Lozano, Elisa; Perugorria, Maria J; Padillo, Francisco J; Bujanda, Luis; Marin, Jose J G

    2017-08-04

    The poor prognosis of cholangiocarcinoma (CCA) is in part due to late diagnosis, which is currently achieved by a combination of clinical, radiological and histological approaches. Available biomarkers determined in serum and biopsy samples to assist in CCA diagnosis are not sufficiently sensitive and specific. Therefore, the identification of new biomarkers, preferably those obtained by minimally invasive methods, such as liquid biopsy, is important. The development of innovative technologies has permitted to identify a significant number of genetic, epigenetic, proteomic and metabolomic CCA features with potential clinical usefulness in early diagnosis, prognosis or prediction of treatment response. Potential new candidates must be rigorously evaluated prior to entering routine clinical application. Unfortunately, to date, no such biomarker has achieved validation for these purposes. This review is an up-to-date of currently used biomarkers and the candidates with promising characteristics that could be included in the clinical practice in the next future. This article is part of a Special Issue entitled: Cholangiocytes in Health and Disease edited by Jesus Banales, Marco Marzioni, Nicholas LaRusso and Peter Jansen. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Clinical analysis of cholangiocarcinoma patients receiving adjuvant radiotherapy

    PubMed Central

    Nantajit, Danupon; Trirussapanich, Pornwaree; Rojwatkarnjana, Sunanta; Soonklang, Kamonwan; Pattaranutraporn, Poompis; Laebua, Kanyanee; Chamchod, Sasikarn

    2016-01-01

    Cholangiocarcinoma (CCA) or bile duct cancer is a rare cancer type in developed countries, while its prevalence is increased in southeast Asia, affecting ~33.4 men and ~12.3 women per 100,000 individuals. CCA is one of the most lethal types of cancer. Neo-adjuvant and adjuvant therapies have been shown to have limited efficacy in improving the overall prognosis of patients. Radiotherapy has been reported to prolong the survival times of patients with certain characteristics. The present study retrospectively evaluated the medical records and follow-up data from 27 CCA patients who received radiotherapy at Chulabhorn Hospital (Bangkok, Thailand) between 2008 and 2014. A total of 14 patients underwent surgery followed by adjuvant chemoradiotherapy. Of the 27 CCA patients, 14 had intrahepatic CCA, 2 had extrahepatic CCA and 11 had hilar CCA. The 2-year survival rate was 40.7%. Tumor resectability, clinical symptoms and the Eastern Cooperative Oncology Group performance status score were found to be indicative of patient prognosis. In addition, the planning target volume and biologically effective radiotherapy dose were of prognostic value; however, initial treatment response was ambiguous in predicting survival time. The findings of the present study suggested that the currently used radiotherapy protocols for CCA may require modification to improve their efficacy. PMID:28105359

  20. Intrahepatic cholangiocarcinoma: pathogenesis and rationale for molecular therapies

    PubMed Central

    Sia, D; Tovar, V; Moeini, A; Llovet, JM

    2013-01-01

    Intrahepatic cholangiocarcinoma (ICC) is an aggressive malignancy with very poor prognosis. Genome-wide, high-throughput technologies have made major advances in understanding the molecular basis of this disease, although important mechanisms are still unclear. Recent data have revealed specific genetic mutations (for example, KRAS, IDH1 and IDH2), epigenetic silencing, aberrant signaling pathway activation (for example, interleukin (IL)-6/signal transducer and activator of transcription 3 (STAT3), tyrosine kinase receptor-related pathways) and molecular subclasses with unique alterations (for example, proliferation and inflammation subclasses). In addition, some ICCs share common genomic traits with hepatocellular carcinoma. All this information provides the basis to explore novel targeted therapies. Currently, surgery at early stage is the only effective therapy. At more advanced stages, chemotherapy regimens are emerging (that is, cisplatin plus gemcitabine), along with molecular targeted agents tested in several ongoing clinical trials. Nonetheless, a first-line conclusive treatment remains an unmet need. Similarly, there are no studies assessing tumor response related with genetic alterations. This review explores the recent advancements in the knowledge of the molecular alterations underlying ICC and the future prospects in terms of therapeutic strategies leading towards a more personalized treatment of this neoplasm. PMID:23318457

  1. The anticancer effects of Resina Draconis extract on cholangiocarcinoma.

    PubMed

    Wen, Feng; Zhao, Xiangxuan; Zhao, Yun; Lu, Zaiming; Guo, Qiyong

    2016-11-01

    Cholangiocarcinoma (CCA) is a relatively rare, heterogeneous malignant tumor with poor clinical outcomes. Because of high insensitivity to chemotherapy and radiotherapy, there are no effective treatment options. Efforts to identify and develop new agents for prevention and treatment of this deadly disease are urgent. Here, we assessed the apoptotic cytotoxicity of Resina Draconis extract (RDE) using in vitro and in vivo assays and identified the mechanisms underlying antitumor effects of RDE. RDE was obtained via vacuum distillation of Resina Draconis with 75 % ethanol. The ethanol extract could inhibit CCA cell proliferation and trigger apoptotic cell death in both QBC939 and HCCC9810 cell lines in a time- and concentration-dependent manner. RDE treatment resulted in intracellular caspase-8 and poly (ADP-ribose) polymerase protease activation. RDE significantly downregulated antiapoptotic protein survivin expression and upregulated proapoptotic protein Bak expression. RDE also inhibited CCA tumor growth in vivo. We observed that human CCA tissues had much higher survivin expression than did paired adjacent normal tissue. Taken together, the current data suggested that RDE has anticancer effects on CCA, and that RDE could function as a novel anticancer agent to benefit patients with CCA.

  2. Cholangiocarcinoma in primary sclerosing cholangitis: risk factors and clinical presentation.

    PubMed

    Boberg, K M; Bergquist, A; Mitchell, S; Pares, A; Rosina, F; Broomé, U; Chapman, R; Fausa, O; Egeland, T; Rocca, G; Schrumpf, E

    2002-10-01

    Primary sclerosing cholangitis (PSC) confers a high risk of cholangiocarcinoma (CC) development. Since patients at risk of CC may be selected for early liver transplantation, it is a challenge to identify any predisposing factors. We compared the presentation and natural history of a large number of PSC patients with and without later CC development to identify features associated with risk of CC. Clinical and laboratory data from presentation and follow-up were collected from 394 PSC patients from five European countries. The cohort included 48 (12.2%) patients with CC. CC was diagnosed within the first year after diagnosis of PSC in 24 (50%) cases and in 13 (27%) patients at intended liver transplantation. Jaundice, pruritus, abdominal pain and fatigue were significantly more frequent at diagnosis of PSC in the group that developed CC, but not after exclusion of cases diagnosed within the first year. Inflammatory bowel disease was diagnosed at least 1 year before PSC more often among patients with CC development than among those without (90% and 65%, respectively: P = 0.001). The duration of inflammatory bowel disease before diagnosis of PSC was significantly longer in patients who developed CC than in the remaining group (17.4 years and 9.0 years, respectively: P=0.009 in multivariate analysis). A high proportion of CC cases is diagnosed within the first year after diagnosis of PSC. A long history of inflammatory bowel disease is a risk factor for CC development.

  3. WNT signaling drives cholangiocarcinoma growth and can be pharmacologically inhibited.

    PubMed

    Boulter, Luke; Guest, Rachel V; Kendall, Timothy J; Wilson, David H; Wojtacha, Davina; Robson, Andrew J; Ridgway, Rachel A; Samuel, Kay; Van Rooijen, Nico; Barry, Simon T; Wigmore, Stephen J; Sansom, Owen J; Forbes, Stuart J

    2015-03-02

    Cholangiocarcinoma (CC) is typically diagnosed at an advanced stage and is refractory to surgical intervention and chemotherapy. Despite a global increase in the incidence of CC, little progress has been made toward the development of treatments for this cancer. Here we utilized human tissue; CC cell xenografts; a p53-deficient transgenic mouse model; and a non-transgenic, chemically induced rat model of CC that accurately reflects both the inflammatory and regenerative background associated with human CC pathology. Using these systems, we determined that the WNT pathway is highly activated in CCs and that inflammatory macrophages are required to establish this WNT-high state in vivo. Moreover, depletion of macrophages or inhibition of WNT signaling with one of two small molecule WNT inhibitors in mouse and rat CC models markedly reduced CC proliferation and increased apoptosis, resulting in tumor regression. Together, these results demonstrate that enhanced WNT signaling is a characteristic of CC and suggest that targeting WNT signaling pathways has potential as a therapeutic strategy for CC.

  4. WNT signaling drives cholangiocarcinoma growth and can be pharmacologically inhibited

    PubMed Central

    Boulter, Luke; Guest, Rachel V.; Kendall, Timothy J.; Wilson, David H.; Wojtacha, Davina; Robson, Andrew J.; Ridgway, Rachel A.; Samuel, Kay; Van Rooijen, Nico; Barry, Simon T.; Wigmore, Stephen J.; Sansom, Owen J.; Forbes, Stuart J.

    2015-01-01

    Cholangiocarcinoma (CC) is typically diagnosed at an advanced stage and is refractory to surgical intervention and chemotherapy. Despite a global increase in the incidence of CC, little progress has been made toward the development of treatments for this cancer. Here we utilized human tissue; CC cell xenografts; a p53-deficient transgenic mouse model; and a non-transgenic, chemically induced rat model of CC that accurately reflects both the inflammatory and regenerative background associated with human CC pathology. Using these systems, we determined that the WNT pathway is highly activated in CCs and that inflammatory macrophages are required to establish this WNT-high state in vivo. Moreover, depletion of macrophages or inhibition of WNT signaling with one of two small molecule WNT inhibitors in mouse and rat CC models markedly reduced CC proliferation and increased apoptosis, resulting in tumor regression. Together, these results demonstrate that enhanced WNT signaling is a characteristic of CC and suggest that targeting WNT signaling pathways has potential as a therapeutic strategy for CC. PMID:25689248

  5. Is Surgical Resection Justified for Advanced Intrahepatic Cholangiocarcinoma?

    PubMed Central

    Yoh, Tomoaki; Hatano, Etsuro; Yamanaka, Kenya; Nishio, Takahiro; Seo, Satoru; Taura, Kojiro; Yasuchika, Kentaro; Okajima, Hideaki; Kaido, Toshimi; Uemoto, Shinji

    2016-01-01

    Backgrounds Prognosis for patients with advanced intrahepatic cholangiocarcinoma (ICC) with intrahepatic metastasis (IM), vascular invasion (VI), or regional lymph node metastasis (LM) remains poor. The aim of this study was to clarify the indications for surgical resection for advanced ICC. Methods We retrospectively divided 213 ICC patients treated at Kyoto University Hospital between 1993 and 2013 into a resection (n=164) group and a non-resection (n=49) group. Overall survival was assessed after stratification for the presence of IM, VI, or LM. Results Overall median survival times (MSTs) for the resection and non-resection groups were 26.0 and 7.1 months, respectively (p<0.001). After stratification, MSTs in the resection and non-resection groups, respectively, were 18.7 vs. 7.0 months for patients with IM (p<0.001), 23.4 vs. 5.7 months for those with VI (p<0.001), and 12.8 vs. 5.5 months for those with LM (p<0.001). Conclusion When macroscopic curative resection is possible, surgical resection can be justified for some advanced ICC patients with IM, VI, or LM. PMID:27781200

  6. First Reported Case of Primary Intrahepatic Cholangiocarcinoma with Pure Squamous Cell Histology: A Case Report

    PubMed Central

    Lubana, Sandeep Singh; Singh, Navdeep; Seligman, Barbara; Tuli, Sandeep S.; Heimann, David M.

    2015-01-01

    Patient: Male, 64 Final Diagnosis: Intrahepatic cholangiocarcinoma with pure squamous cell Symptoms: — Medication: — Clinical Procedure: — Specialty: — Objective: Rare disease Background: In the United States, approximately 2500 cases of cholangiocarcinoma occur each year. The average incidence is 1 case/100 000 persons each year. Surgical resection is the mainstay for the treatment of cholangiocarcinoma. The result of surgery depends on location of the tumor, extent of tumor penetration of the bile duct, tumor-free resection margins, and lymph node and distant metastases. There has been an increase in the incidence of intrahepatic cholangiocarcinoma (IHCC) globally over a period of 30 years from 0.32/100 000 to 0.85/100 000 persons each year. Epidemiologically, the incidence of IHCC has been increasing in the U.S. from year 1973 to 2010. Case Report: We are reporting a first case of primary intrahepatic cholangiocarcinoma of pure squamous cell histology. A 64-year-old man presented with right upper-quadrant pain, jaundice, and weight loss. Imaging studies revealed a large hepatobiliary mass, intrahepatic bile duct dilation, normal common duct, and absence of choledocholithiasis. Delayed-contrast magnetic resonance imaging of the abdomen showed peripheral enhancement of the central lesion, which is typical of cholangiocarcinoma in contrast to hepatocellular carcinoma or metastasis. Cancer antigen 19-9 was markedly elevated. Liver function tests were deranged. Endoscopic retrograde cholangiopancreatography showed high degree of left hepatic duct stricture. Brush cytopathology was positive for atypia. The patient underwent exploratory laparotomy for en-bloc resection of the hepatobiliary mass with colon resection, liver resection, and cholecystectomy. Histology revealed keratinizing squamous cell carcinoma. Based on these findings, a definitive diagnosis of well-differentiated squamous cell carcinoma of the intrahepatic bile duct was made. Conclusions

  7. Induction of biliary cholangiocarcinoma cell apoptosis by 103Pd cholangial radioactive stent gamma-rays.

    PubMed

    He, Gui-jin; Sun, Dan-dan; Ji, Da-wei; Sui, Dong-ming; Yu, Fa-qiang; Gao, Qin-yi; Dai, Xian-wei; Gao, Hong; Jiang, Tao; Dai, Chao-liu

    2008-06-05

    In recent years, interventional tumor therapy, involving implantation of intra-cholangial metal stents through percutaneous trans-hepatic punctures, has provided a new method for treating cholangiocarcinoma. (103)Pd cholangial radioactive stents can concentrate high radioactive dosages into the malignant tumors and kill tumor cells effectively, in order to prevent re-stenosis of the lumen caused by a relapsed tumor. The aim of the present study was to investigate the efficacy of gamma-rays released by the (103)Pd biliary duct radioactive stent in treating cholangiocarcinoma via induction of biliary cholangiocarcinoma cell apoptosis. A group of biliary duct cancer cells was collectively treated with a dose of gamma-rays. Cells were then examined by the 3-(4, 5-dimethyl thiazol-2-yl)-2, 5-diphenyl terazolium-bromide (MTT) technique for determining the inhibition rate of the biliary duct cancer cells, as well as with other methods including electron microscopy, DNA agarose gel electrophoresis, and flow cytometry were applied for the evaluation of their morphological and biochemical characteristics. The growth curve and the growth inhibition rate of the cells were determined, and the changes in the ultrastructure of the cholangiocarcinoma cells and the DNA electrophoresis bands were examined under a UV-lamp. The gamma-ray released by (103)Pd inhibited cholangiocarcinoma cell growth, as demonstrated when the growth rate of the cells was stunned by a gamma-ray with a dosage larger than 197.321 MBq. Typical features of cholangiocarcinoma cell apoptosis were observed in the 197.321 MBq dosage group, while cell necrosis was observed when irradiated by a dosage above 245.865 MBq. DNA agarose gel electrophoresis results were different between the 197.321 MBq irradiation dosage group, the 245.865 MBq irradiation dosage