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Daejeon, South Korea

Lee N.,Pohang University of Science and Technology | Kwon J.-H.,CbsBioscience Inc. | Kim Y.B.,Ajou University | Kim S.-H.,Pohang University of Science and Technology | And 6 more authors.
Oncotarget | Year: 2015

We identified the specific role of vaccinia-related kinase 1 (VRK1) in the progression of hepatocellular carcinoma (HCC) and evaluated its therapeutic and prognostic potential. VRK1 levels were significantly higher in HCC cell lines than a normal hepatic cell line, and were higher in HCC than non-tumor tissue. VRK1 knockdown inhibited the proliferation of SK-Hep1, SH-J1 and Hep3B cells; moreover, depletion of VRK1 suppressed HCC tumor growth in vivo. We also showed that VRK1 knockdown increased the number of G1 arrested cells by decreasing cyclin D1 and p-Rb while upregulating p21 and p27, and that VRK1 depletion downregulated phosphorylation of CREB, a transcription factor regulating CCND1. Additionally, we found that luteolin, a VRK1 inhibitor, suppressed HCC growth in vitro and in vivo, and that the aberrant VRK1 expression correlated with poor prognostic features of HCC. High levels of VRK1 were associated with shorter overall and disease-free survival and higher recurrence rates. Taken together, our findings suggest VRK1 may act as a tumor promoter by controlling the level of cell cycle regulators associated with G1/S transition and could potentially serve as a therapeutic target and/or prognostic biomarker for HCC. Source

Park C.W.,Pohang University of Science and Technology | Hong S.M.,Pohang University of Science and Technology | Kim E.-S.,Pohang University of Science and Technology | Kwon J.H.,CbsBioscience Inc. | And 3 more authors.
Autophagy | Year: 2013

BNIP3 (BCL2/adenovirus E1B 19 kDa interacting protein 3) is an atypical BH3-only protein that is induced by hypoxiainducible factor 1 (HI F1) under hypoxia. BNIP3 is primarily regulated at the transcriptional level. However, little is known about the underlying mechanism of BNIP3 degradation. In this study, we found that BNIP3 was downregulated when hypoxia was accompanied by amino acid starvation. The BNIP3 downregulation did not occur at the transcription level and was independent of HI F1A. BNIP3 was primarily degraded by the proteasome, but BNIP3 was subjected to both proteasomal and autophagic degradation in response to starvation. The autophagic degradation of BNIP3 was dependent on ATG7 and MAP1LC3. We determined that autophagic degradation of BNIP3 was specifically regulated by ULK1 via the MTOR-AMPK pathway. Moreover, we confirmed that BNIP3 could play a protective role in tumor cells under hypoxia, and the treatment with Torin1, an MTOR inhibitor, decreased the BNIP3 level and enhanced the death of hypoxic tumor cells. © 2013 Landes Bioscience. Source

Cbs Bioscience Co. | Date: 2010-04-16

The present invention relates to a marker for the prognosis of liver cancer; a composition for estimating the prognosis of liver cancer, which contains a substance for detecting a change in the expression level of the prognostic marker for liver cancer; a kit for estimating the prognosis of liver cancer, which contains the composition for estimating liver cancer prognosis; a method for estimating the prognosis of liver cancer using the marker for liver cancer prognosis; and a method for screening a therapeutic agent for liver cancer using the marker for the prognosis of liver cancer.

Provided herein is an analytical method for determining whether a hepatocellular carcinoma patient has susceptibility or resistance to sorafenib treatment by analyzing the mRNA expression of FGFR1, optionally along with the mRNA expressions of other biomarkers (i.e., VEGFR2, PDGFR, c-KIT, c-RAF, EGFR, and/or mTOR) to select a patient having susceptibility to sorafenib treatment and a patient having resistance to sorafenib treatment before employing molecular targeted therapy with sorafenib.

Lee N.,Pohang University of Science and Technology | Kim D.-K.,Pohang University of Science and Technology | Kim E.-S.,Chonnam National University | Kim E.-S.,University of Washington | And 8 more authors.
Proteomics | Year: 2014

Sirtuins are NAD+-dependent deacetylases that regulate a range of cellular processes. Although diverse functions of sirtuins have been proposed, those functions of SIRT6 and SIRT7 that are mediated by their interacting proteins remain elusive. In the present study, we identified SIRT6- and SIRT7-interacting proteins, and compared their interactomes to investigate functional links. Our interactomes revealed 136 interacting proteins for SIRT6 and 233 for SIRT7 while confirming seven and 111 proteins identified previously for SIRT6 and SIRT7, respectively. Comparison of SIRT6 and SIRT7 interactomes under the same experimental conditions disclosed 111 shared proteins, implying related functional links. The interaction networks of interactomes indicated biological processes associated with DNA repair, chromatin assembly, and aging. Interactions of two highly acetylated proteins, nucleophosmin (NPM1) and nucleolin, with SIRT6 and SIRT7 were confirmed by co-immunoprecipitation. NPM1 was found to be deacetylated by both SIRT6 and SIRT7. In senescent cells, the acetylation level of NPM1 was increased in conjunction with decreased levels of SIRT6 and SIRT7, suggesting that the acetylation of NPM1 could be regulated by SIRT6 and SIRT7 in the aging process. Our comparative interactomic study of SIRT6 and SIRT7 implies important functional links to aging by their associations with interacting proteins. All MS data have been deposited in the ProteomeXchange with identifiers PXD000159 and PXD000850 (http://proteomecentral.proteomexchange.org/dataset/PXD000159, http://proteomecentral.proteomexchange.org/dataset/PXD000850). © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

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