Research Institute National Cancer Center

Gyeonggi, South Korea

Research Institute National Cancer Center

Gyeonggi, South Korea
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Woo J.K.,Seoul National University | Woo J.K.,Gachon University | Jang J.-E.,Gachon University | Kang J.-H.,Research Institute National Cancer Center | And 5 more authors.
Molecular Cancer Therapeutics | Year: 2017

Heat shock protein 90 (HSP90) stabilizing oncoproteins has been an attractive target in cancer therapy. 17-N-Allylamino-17-demethoxygeldanamycin (17-AAG), an HSP90 inhibitor, was tested in phase II/III clinical trials, but due to lack of efficacy, clinical evaluation of 17-AAG has achieved limited success, which led to resistance to 17-AAG. However, the mechanism of 17-AAG resistance has not clearly been identified. Here, we identified LGALS3BP (Lectin, galactoside-binding soluble 3 binding protein), a secretory glycoprotein, as a 17-AAG resistance factor. In the clinical reports, it was suggested that LGALS3BP was associated with low survival rate, development of cancer progression, and enhancement of metastasis in human cancers. As we confirmed that the LGALS3BP level was increased in 17-AAG–resistant cells (H1299_17R) compared with that of the parental cell line (H1299_17P), knockdown of LGALS3BP expression increased sensitivity to 17-AAG in H1299_17R cells. Overexpression of LGALS3BP also augmented PI3K/Akt and ERK signaling pathways. Furthermore, we determined that the PI3K/Akt signaling pathway was involved in LGALS3BP-mediated 17-AAG resistance in vitro and in vivo, demonstrating that LGALS3BP mediates the resistance against 17-AAG through PI3K/Akt activation rather than ERK activation. These findings suggest that LGALS3BP would be a target to overcome resistance to 17-AAG in lung cancer. For example, the combination of 17-AAG and PI3K/Akt inhibitor would effectively suppress acquired resistance to 17-AAG. In conclusion, targeting of LGALS3BP-mediated–specific survival signaling pathway in resistant cells may provide a novel therapeutic model for the cancer therapy. ©2017 AACR.

Shin J.H.,Research Institute National Cancer Center | Park H.B.,Research Institute National Cancer Center | Oh Y.M.,Research Institute National Cancer Center | Lim D.P.,Research Institute National Cancer Center | And 7 more authors.
Blood | Year: 2012

Cytotoxic T lymphocyte-associated antigen 4 (CTLA4) has been known to be a strong tolerance-inducing inhibitory receptor on T-cell surface. Systemic blocking of CTLA4 function with blocking antibodies has been regarded as an attractive strategy to enhance antitumor immunity. However, this strategy accompanies systemic autoimmune side effects that are sometimes problematic. Therefore, we developed a novel CTLA4 mutant that could be expressed in tumor antigen-specific T cells to enhance antitumor effect without systemic autoimmunity. This mutant, named CTLA4-CD28 chimera, consists of extracellular and transmembrane domains of CTLA4, linked with cytoplasmic CD28 domain. Overexpression of CTLA4-CD28 chimera in T cells delivered stimulatory signals rather than inhibitory signals of CTLA4 and significantly enhanced T-cell reactivity. Although this effect was observed in both CD4 and CD8 T cells, the effect on CD4 T cells was predominant. CTLA4-CD28 chimera gene modification of CD4 T cells significantly enhanced antitumor effect of unmodified CD8T cells. Nonetheless, the gene modification of CD8 T cells along with CD4 T cells further maximized antitumor effect of T cells in 2 different murine tumor models. Thus, CTLA4-CD28 chimera gene modification of both tumor antigen-specific CD4 and CD8 T cells would be an ideal way of modulating CTLA4 function to enhance tumor-specific T-cell reactivity. © 2012 by The American Society of Hematology.

Lim S.-C.,Chosun University | Duong H.-Q.,Chosun University | Choi J.E.,Chosun University | Lee T.-B.,Chosun University | And 3 more authors.
Carcinogenesis | Year: 2011

Ursodeoxycholic acid (UDCA) is known as a suppressor of cholestatic liver diseases and colorectal cancer development. Here, we demonstrate that UDCA induces apoptosis without necrotic features in SNU601, SNU638, SNU1 and SNU216 human gastric cancer cells, implying its possible use as an effective chemotherapeutic agent in treatment of gastric cancer. UDCA-induced apoptosis was dominantly mediated by an extrinsic pathway dependent on caspase-8, -6 and -3. UDCA increased expression of death receptor 5 [(DR5), also known as tumor necrosis factorrelated apoptosis-inducing ligand (TRAIL) receptor 2], and this DR appeared to be responsible for UDCA-induced apoptosis, as evidenced by DR5 knockdown. UDCA triggered formation of lipid rafts that played crucial roles in UDCA-induced apoptotic actions. Lipid rafts were required not only for provision of a proper site for DR5 action but also for mediation of DR5 expression. In addition, reactive oxygen species (ROS) and protein kinase C (PKC) d appeared to be implicated in UDCA-induced raft-dependent DR5 expression. Our results indicate that UDCAinduced apoptosis is mediated by DR5 expression, which is regulated by the raft formation/ROS production/PKCd activation pathway and DR5 localization into lipid rafts in gastric cancer cells. Tumor-suppressive activity of UDCAwas confirmed in an in vivo system: UDCA (120 mg/kg/day) significantly decreased tumor growth in gastric cancer xenograft mice. Taken together, our results demonstrate that UDCA can be used as a potent chemotherapeutic agent for treatment of gastric cancer. © The Author 2011. Published by Oxford University Press. All rights reserved.

Paek A.R.,Research Institute National Cancer Center | You H.J.,Research Institute National Cancer Center
Molecules and Cells | Year: 2011

Previously, we reported that the expression of zinc-finger protein 143 (ZNF143) was induced by insulin-like growth factor-1 (IGF-1) via reactive oxygen species (ROS)- and phosphatidylinositide-3-kinase (PI3-kinase)-linked pathways in colon cancer cells. Here, we investigated whether GAIP-interacting protein, C-terminus (GIPC), a binding partner of IGF-1R, is involved in ZNF143 expression through IGF-1 and IGF-1R signaling in colon cancer cells. The knockdown of GIPC in colon cancer cells reduced ZNF143 expression in response to IGF-1. IGF-1 signaling through its receptor, leading to the phosphorylation and activation of the PI3-kinase-Akt pathway and mitogenactivated protein kinases (MAPKs) was unaffected by the knockdown of GIPC, indicating the independence of the GIPC-linked pathway from PI3-kinase- and MAPK-linked signaling in IGF-1-induced ZNF143 expression. In accordance with previous results in breast cancer cells (Choi et al., 2010), the knockdown of GIPC reduced ROS production in response to IGF-1 in colon cancer cells. Furthermore, the knockdown of GIPC reduced the expression of Rad51, which is regulated by ZNF143, in response to IGF-1 in colon cancer cells. Taken together, these data suggest that GIPC is involved in IGF-1 signaling leading to ZNF143 expression through the regulation of ROS production, which may play a role for colon cancer tumorigenesis. © 2011 KSMCB.

Seo H.K.,Pusan National University | Seo J.B.,Pusan National University | Nam J.-K.,Research Institute National Cancer Center | Jeong K.-C.,Research Institute National Cancer Center | And 4 more authors.
Oncotarget | Year: 2014

Survivin is a member of the inhibitors of apoptosis protein family. Here, we examined survivin expression and confirmed abundant survivin expression in bladder cancer cells. This expression pattern indicated that the transcriptional regulatory elements that control survivin expression could be utilized to discriminate cancer from normal cells. We therefore generated a novel adenovirus termed Ad5/35E1apsurvivinE4 with the following characteristics: 1) E1A and E4 protein expression was dependent on survivin promoter activity; 2) the green fluorescence protein gene was inserted into the genome under the control of the CMV promoter; 3) most of the E3 sequences were deleted, but the construct was still capable of expressing the adenovirus death protein with potent cytotoxic effects; and 4) the fiber knob was from serotype 35 adenovirus. As expected from the abundant survivin expression observed in bladder cancer cells, Ad5/35E1apsurvivinE4 replicated better in cancer cells than in normal cells by a factor of 106 to 102. Likewise, Ad5/35E1apsurvivinE4 exerted greater cytotoxic effects on all bladder cancer cell lines tested. Importantly, Ad5/35E1apsurvivinE4 inhibited the growth of Ku7-Luc orthotopic xenografts in nude mice. Taken together, Ad5/35E1apsurvivinE4 indicates that the survivin promoter may be utilized for the development of a replication-competent adenovirus to target bladder cancers.

Shin S.-P.,Research Institute National Cancer Center | Shin S.-P.,Sungkyunkwan University | Seo H.-H.,Research Institute National Cancer Center | Shin J.-H.,Research Institute National Cancer Center | And 8 more authors.
Molecular Therapy | Year: 2013

Adenoviruses harboring the herpes simplex virus thymidine kinase (HSVtk) gene under the regulation of a trans-splicing ribozyme targeting human telomerase reverse transcriptase (hTERT-TR) show marked and specific antitumor activity. In addition to inducing tumor cell death by direct cytotoxicity, it is becoming clear that HSVtk also induces antitumor immunity. Programmed death ligand 1 (PD-L1) expressed on tumor cell surfaces mediates tumor-induced immunoresistance by inhibiting PD1-expressing tumor-infiltrating T cells. Here, we explored whether a soluble form of PD1 (sPD1-Ig), which blocks PD-L1, could synergize with TERT-TR-regulated HSVtk to enhance the adenoviral therapeutic efficacy by boosting antitumor immunity. Tumor antigen released by HSVtk-transduced tumors successfully primed tumor antigen-specific CD8 T cells via dendritic cells (DC). Regression of murine tumors was markedly enhanced when sPD1-Ig was incorporated into the adenovirus as compared with a single-module adenovirus expressing only HSVtk. This effect was abolished by CD8 T-cell depletion. Consistent with this, following adoptive transfer of tumor antigen-specific CD8 T cells into tumor-bearing Rag1-/- mice, dual-module adenovirus significantly enhanced CD8 T cell-mediated tumor rejection. In addition, secondary tumor challenge at a distal site was completely suppressed in mice treated with a dual-module adenovirus. These results suggest that a dual-targeting strategy to elicit both tumor antigen priming and tumor-induced immunoresistance enhances CD8 T cell-mediated antitumor immunity. Copyright © 2013, The American Society of Gene & Cell Therapy.

Kim J.H.,Research Institute National Cancer Center | Kim J.H.,University of Seoul | Yoon E.-K.,Research Institute National Cancer Center | Yoon E.-K.,Ewha Womans University | And 10 more authors.
Apoptosis | Year: 2013

Microtubule inhibitors (MTIs) such as Taxol have been used for treating various malignant tumors. Although MTIs have been known to induce cell death through mitotic arrest, other mechanisms can operate in MTI-induced cell death. Especially, the role of p53 in this process has been controversial for a long time. Here we investigated the function of p53 in Taxol-induced apoptosis using p53 wild type and p53 null cancer cell lines. p53 was upregulated upon Taxol treatment in p53 wild type cells and deletion of p53 diminished Taxol-induced apoptosis. p53 target proteins including MDM2, p21, BAX, and β-isoform of PUMA were also upregulated by Taxol in p53 wild type cells. Conversely, when the wild type p53 was re-introduced into two different p53 null cancer cell lines, Taxol-induced apoptosis was enhanced. Among post-translational modifications that affect p53 stability and function, p53 acetylation, rather than phosphorylation, increased significantly in Taxol-treated cells. When acetylation was enhanced by anti-Sirt1 siRNA or an HDAC inhibitor, Taxol-induced apoptosis was enhanced, which was not observed in p53 null cells. When an acetylation-defective mutant of p53 was re-introduced to p53 null cells, apoptosis was partially reduced compared to the re-introduction of the wild type p53. Thus, p53 plays a pro-apoptotic role in Taxol-induced apoptosis and acetylation of p53 contributes to this pro-apoptotic function in response to Taxol in several human cancer cell lines, suggesting that enhancing acetylation of p53 could have potential implication for increasing the sensitivity of cancer cells to Taxol. © 2012 Springer Science+Business Media New York.

PubMed | Research Institute National Cancer Center and Seoul National University
Type: Journal Article | Journal: Immune network | Year: 2016

Programmed death-1 (PD-1) is a strong negative regulator of T lymphocytes in tumor-microenvironment. By engaging PD-1 ligand (PD-L1) on tumor cells, PD-1 on T cell surface inhibits anti-tumor reactivity of tumor-infiltrating T cells. Systemic blockade of PD-1 function using blocking antibodies has shown significant therapeutic efficacy in clinical trials. However, approximately 10 to 15% of treated patients exhibited serious autoimmune responses due to the activation of self-reactive lymphocytes. To achieve selective activation of tumor-specific T cells, we generated T cells expressing a dominant-negative deletion mutant of PD-1 (PD-1 decoy) via retroviral transduction. PD-1 decoy increased IFN- secretion of antigen-specific T cells in response to tumor cells expressing the cognate antigen. Adoptive transfer of PD-1 decoy-expressing T cells into tumor-bearing mice potentiated T cell-mediated tumor regression. Thus, T cell-specific blockade of PD-1 could be a useful strategy for enhancing both efficacy and safety of anti-tumor T cell therapy.

PubMed | Korea University, Research Institute National Cancer Center and Korea Research Institute of Bioscience and Biotechnology
Type: | Journal: Angewandte Chemie (International ed. in English) | Year: 2016

p53 is an important tumor-suppressor protein deactivation of which by mdm2 results in cancers. A SUMO-specific protease4 (SUSP4) was shown to rescue p53 from mdm2-mediated deactivation, but the mechanism is unknown. The discovery by NMR spectroscopy of a p53 rescue motif in SUSP4 that disrupts p53-mdm2 binding is presented. This 29-residue motif is pre-populated with two transient helices connected by a hydrophobic linker. The helix at the C-terminus binds to the well-known p53-binding pocket in mdm2 whereas the N-terminal helix serves as an affinity enhancer. The hydrophobic linker binds to a previously unidentified hydrophobic crevice in mdm2. Overall, SUSP4 appears to use two synergizing modules, the p53 rescue motif described here and a globular-structured SUMO-binding catalytic domain, to stabilize p53. A p53 rescue motif peptide exhibits an anti-tumor activity in cancer cell lines expressing wild-type p53. A pre-structures motif in the intrinsically disordered proteins is thus important for target recognition.

Rome Paek A.,Carcinogenesis Branch | Kim S.H.,Carcinogenesis Branch | Kim S.S.,Carcinogenesis Branch | Kim K.T.,Research Institute National Cancer Center | You H.J.,Carcinogenesis Branch
Experimental and Molecular Medicine | Year: 2010

Expression of zinc-finger protein 143 (ZNF143), a human homolog of the Xenopus transcriptional activator protein Staf, is induced by various DNA-damaging agents including etoposide, doxorubicin, and γ- irradiation. ZNF143 binds to cisplatin-modified DNA, and its levels are increased in cancer cells that are resistant to anticancer drugs, including cisplatin, suggesting that it plays a role in carcinogenesis and cancer cell survival. However, the mechanism of ZNF143 induction in cancer cells remains unclear. Both insulin-like growth factor-1 (IGF-1) and its receptor (IGF-1R) have been reported to be overexpressed in cancer cells and to be related to anticancer drug resistance, but the identity of the relevant signaling mediators is still being investigated. In the present study, we observed that IGF-1 was able to induce ZNF143 expression in HCT116 human colon cancer cells and that wortmannin, an inhibitor of phosphatidylinositide 3-kinase (PI3-kinase), inhibited this induction, as did diphenyleneiodonium (DPI), an NADPH oxidase inhibitor, and monodansylcardavarine (MDC), a receptor internalization inhibitor. Treatment with MDC dedecreased the IGF-1-stimulated generation of reactive oxygen species. Taken together, these data suggest that IGF-1 induces ZNF143 expression in cancer cells via PI3-kinase and reactive oxygen species generation during receptor internalization.

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