Publications by authors named "Sungyoul Hong"

93 Publications

Antibody-Based Targeting of Interferon-Beta-1a Mutein in HER2-Positive Cancer Enhances Antitumor Effects Through Immune Responses and Direct Cell Killing.

Front Pharmacol 2020 8;11:608774. Epub 2021 Jan 8.

Laboratory of Molecular Pathology and Cancer Genomics, College of Pharmacy, Seoul National University, Seoul, South Korea.

Type I interferon (IFN) has been approved as an anticancer agent to treat some malignancies. However, IFNs have a short half-life, systemic toxicity, and poor biophysical properties, which prevent it from being widely used for cancer therapy. This study aimed to construct recombinant IFN-β-1a mutein immunocytokines that comprise a human epidermal growth factor receptor 2 (HER2)-targeting antibody and IFN-β muteins with an additional glycosylation, which can overcome the limitation of the cytokine itself. Hence, the molecular design aims to 1) enhance productivity and biophysical properties by adding secondary glycosylation in IFN-β, 2) increase the therapeutic index of IFN-β therapy by preferential retention at the tumor by possessing high affinity for HER2-expressing cancer cells, and 3) improve the pharmacokinetics and, thus, the convenience of IFN-β administration. The yield of trastuzumab-IFN-β mutein was higher than that of trastuzumab-wild-type IFN-β in the mammalian cell culture system. Trastuzumab-IFN-β mutein showed similar IFN activity and HER2-targeting ability equivalent to that of IFN-β mutein and trastuzumab, respectively. Trastuzumab-IFN-β mutein directly inhibited the growth of HER2-positive gastric cancer cell lines and was more effective than trastuzumab or IFN-β mutein alone. Trastuzumab-IFN-β mutein and IFN-β mutein displayed enhanced immune cell-mediated cytotoxicity. Collectively, trastuzumab-IFN-β mutein may have indirect immune cell-mediated antitumor effects and direct cell growth inhibitory effects. Tumor-targeting effect of trastuzumab-IFN-β mutein was analyzed using fluorescence imaging. The accumulation of trastuzumab-IFN-β mutein was observed in HER2-positive tumors rather than other tissues except the liver. To evaluate the both direct tumor growth inhibition effect and indirect immune cell-mediated antitumor effect, we tested the effect of trastuzumab-IFN-β mutein in HER2-positive cancer xenograft models using nude mice or humanized mice. Trastuzumab-IFN-β mutein could significantly enhance tumor regression when compared with trastuzumab or IFN-β mutein. In addition, an increase in tumor-infiltrating lymphocytes was observed in the trastuzumab-IFN-β mutein-treated group, implying that the tumor-targeting IFN-β may have an enhanced antitumor effect through increased immune response. Therefore, targeting IFN-β with an anti-HER2 monoclonal antibody makes the immunocytokine more potent than either agent alone. These novel findings suggest that trastuzumab-IFN-β mutein merits clinical evaluation as a new candidate of anticancer therapeutics.
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http://dx.doi.org/10.3389/fphar.2020.608774DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7832035PMC
January 2021

RGS2-mediated translational control mediates cancer cell dormancy and tumor relapse.

J Clin Invest 2021 01;131(1)

Creative Research Initiative Center for Concurrent Control of Emphysema and Lung Cancer, College of Pharmacy.

Slow-cycling/dormant cancer cells (SCCs) have pivotal roles in driving cancer relapse and drug resistance. A mechanistic explanation for cancer cell dormancy and therapeutic strategies targeting SCCs are necessary to improve patient prognosis, but are limited because of technical challenges to obtaining SCCs. Here, by applying proliferation-sensitive dyes and chemotherapeutics to non-small cell lung cancer (NSCLC) cell lines and patient-derived xenografts, we identified a distinct SCC subpopulation that resembled SCCs in patient tumors. These SCCs displayed major dormancy-like phenotypes and high survival capacity under hostile microenvironments through transcriptional upregulation of regulator of G protein signaling 2 (RGS2). Database analysis revealed RGS2 as a biomarker of retarded proliferation and poor prognosis in NSCLC. We showed that RGS2 caused prolonged translational arrest in SCCs through persistent eukaryotic initiation factor 2 (eIF2α) phosphorylation via proteasome-mediated degradation of activating transcription factor 4 (ATF4). Translational activation through RGS2 antagonism or the use of phosphodiesterase 5 inhibitors, including sildenafil (Viagra), promoted ER stress-induced apoptosis in SCCs in vitro and in vivo under stressed conditions, such as those induced by chemotherapy. Our results suggest that a low-dose chemotherapy and translation-instigating pharmacological intervention in combination is an effective strategy to prevent tumor progression in NSCLC patients after rigorous chemotherapy.
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http://dx.doi.org/10.1172/JCI136779DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7773398PMC
January 2021

The ATF6-EGF Pathway Mediates the Awakening of Slow-Cycling Chemoresistant Cells and Tumor Recurrence by Stimulating Tumor Angiogenesis.

Cancers (Basel) 2020 Jul 2;12(7). Epub 2020 Jul 2.

Creative Research Initiative Center for concurrent control of emphysema and lung cancer, College of Pharmacy, Seoul National University, Seoul 08826, Korea.

Slow-cycling cancer cells (SCCs) with a quiescence-like phenotype are believed to perpetrate cancer relapse and progression. However, the mechanisms that mediate SCC-derived tumor recurrence are poorly understood. Here, we investigated the mechanisms underlying cancer recurrence after chemotherapy, focusing on the interplay between SCCs and the tumor microenvironment. We established a preclinical model of SCCs by exposing non-small-cell lung cancer (NSCLC) cells to either the proliferation-dependent dye carboxyfluorescein diacetate succinimidyl ester (CFSE) or chemotherapeutic drugs. An RNA sequencing analysis revealed that the established SCCs exhibited the upregulation of a group of genes, especially epidermal growth factor (EGF). Increases in the number of vascular endothelial growth factor receptor (VEGFR)-positive vascular endothelial cells and epidermal growth factor receptor (EGFR) activation were found in NSCLC cell line- and patient-derived xenograft tumors that progressed upon chemotherapy. EGFR tyrosine kinase inhibitors effectively suppressed the migration and tube formation of vascular endothelial cells. Furthermore, activating transcription factor 6 (ATF6) induced the upregulation of EGF, and its antagonism effectively suppressed these SCC-mediated events and inhibited tumor recurrence after chemotherapy. These results suggest that the ATF6-EGF signaling axis in SCCs functions to trigger the angiogenesis switch in residual tumors after chemotherapy and is thus a driving force for the switch from SCCs to actively cycling cancer cells, leading to tumor recurrence.
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http://dx.doi.org/10.3390/cancers12071772DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7407555PMC
July 2020

Therapeutic Efficacy of ABN401, a Highly Potent and Selective MET Inhibitor, Based on Diagnostic Biomarker Test in -Addicted Cancer.

Cancers (Basel) 2020 Jun 15;12(6). Epub 2020 Jun 15.

College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul 08826, Korea.

The receptor tyrosine kinase c-MET regulates processes essential for tissue remodeling and mammalian development. The dysregulation of c-MET signaling plays a role in tumorigenesis. The aberrant activation of c-MET, such as that caused by gene amplification or mutations, is associated with many cancers. c-MET is therefore an attractive therapeutic target, and inhibitors are being tested in clinical trials. However, inappropriate patient selection criteria, such as low amplification or expression level cut-off values, have led to the failure of clinical trials. To include patients who respond to MET inhibitors, the selection criteria must include oncogenic addiction. Here, the efficacy of ABN401, a MET inhibitor, was investigated using histopathologic and genetic analyses in -addicted cancer cell lines and xenograft models. ABN401 was highly selective for 571 kinases, and it inhibited c-MET activity and its downstream signaling pathway. We performed pharmacokinetic profiling of ABN401 and defined the dose and treatment duration of ABN401 required to inhibit c-MET phosphorylation in xenograft models. The results show that the efficacy of ABN401 is associated with MET status and they highlight the importance of determining the cut-off values. The results suggest that clinical trials need to establish the characteristics of each sample and their correlations with the efficacy of MET inhibitors.
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http://dx.doi.org/10.3390/cancers12061575DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7352216PMC
June 2020

The Interplay between Slow-Cycling, Chemoresistant Cancer Cells and Fibroblasts Creates a Proinflammatory Niche for Tumor Progression.

Cancer Res 2020 06 19;80(11):2257-2272. Epub 2020 Mar 19.

Creative Research Initiative Center for Concurrent Control of Emphysema and Lung Cancer, College of Pharmacy, Seoul National University, Seoul, Republic of Korea.

Quiescent cancer cells are believed to cause cancer progression after chemotherapy through unknown mechanisms. We show here that human non-small cell lung cancer (NSCLC) cell line-derived, quiescent-like, slow-cycling cancer cells (SCC) and residual patient-derived xenograft (PDX) tumors after chemotherapy experience activating transcription factor 6 (ATF6)-mediated upregulation of various cytokines, which acts in a paracrine manner to recruit fibroblasts. Cancer-associated fibroblasts (CAF) underwent transcriptional upregulation of COX2 and type I collagen (Col-I), which subsequently triggered a slow-to-active cycling switch in SCC through prostaglandin E (PGE)- and integrin/Src-mediated signaling pathways, leading to cancer progression. Both antagonism of ATF6 and cotargeting of Src/COX2 effectively suppressed cytokine production and slow-to-active cell cycling transition in SCC, withholding cancer progression. Expression of COX2 and Col-I and activation of Src were observed in patients with NSCLC who progressed while receiving chemotherapy. Public data analysis revealed significant association between and expression and NSCLC relapse. Overall, these findings indicate that a proinflammatory niche created by the interplay between SCC and CAF triggers tumor progression. SIGNIFICANCE: Cotargeting COX2 and Src may be an effective strategy to prevent cancer progression after chemotherapy.
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http://dx.doi.org/10.1158/0008-5472.CAN-19-0631DOI Listing
June 2020

New Preclinical Development of a c-Met Inhibitor and Its Combined Anti-Tumor Effect in c-Met-Amplified NSCLC.

Pharmaceutics 2020 Feb 3;12(2). Epub 2020 Feb 3.

College of Pharmacy, Dongguk University-Seoul, Gyeonggi 10326, Korea.

c-Met is a receptor tyrosine kinase with no commercially available product despite being a pivotal target in cancer progression. Unlike other c-Met inhibitors that fail clinically, ABN401 is a newly synthesized c-Met inhibitor that is not potentially degraded by aldehyde oxidase (AO) in human liver cytosol. This study aimed to determine the physicochemical stability, pharmacokinetics in beagle dogs, and therapeutic effect of ABN401 in a c-Met-amplified non-small-cell lung cancer (NSCLC) patient-derived xenograft (PDX) model. ABN401 was found to be a weak basic compound, with pKa and log values of 7.49 and 2.46, respectively. It is poorly water-soluble but soluble at acidic pH. The accelerated storage stability is dependent on temperature, but the purity remains at over 97% after 6 months. The bioavailability is approximately 30% in dogs and it is highly efficient in the PDX model, achieving around 90% tumor growth inhibition in combination with erlotinib. These observations indicate that the compound is acceptable for the next phase of trials.
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http://dx.doi.org/10.3390/pharmaceutics12020121DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7076440PMC
February 2020

Development of Human Monoclonal Antibody for Claudin-3 Overexpressing Carcinoma Targeting.

Biomolecules 2019 12 28;10(1). Epub 2019 Dec 28.

Laboratory of Molecular Pathology and Cancer Genomics, Research Institute of Pharmaceutical Sciences and College of Pharmacy, Seoul National University, Seoul 08826, Korea.

Most malignant tumors originate from epithelial tissues in which tight junctions mediate cell-cell interactions. Tight junction proteins, especially claudin-3 (CLDN3), are overexpressed in various cancers. Claudin-3 is exposed externally during tumorigenesis making it a potential biomarker and therapeutic target. However, the development of antibodies against specific CLDN proteins is difficult, because CLDNs are four-transmembrane domain proteins with high homology among CLDN family members and species. Here, we developed a human IgG1 monoclonal antibody (h4G3) against CLDN3 through scFv phage display using CLDN3-overexpressing stable cells and CLDN3-embedded lipoparticles as antigens. The h4G3 recognized the native conformation of human and mouse CLDN3 without cross-reactivity to other CLDNs. The binding kinetics of h4G3 demonstrated a sub-nanomolar affinity for CLDN3 expressed on the cell surface. The h4G3 showed antibody-dependent cellular cytotoxicity (ADCC) according to CLDN3 expression levels in various cancer cells by the activation of FcγRIIIa (CD16a). The biodistribution of h4G3 was analyzed by intravenous injection of fluorescence-conjugated h4G3 which showed that it localized to the tumor site in xenograft mice bearing CLDN3-expressing tumors. These results indicate that h4G3 recognizes CLDN3 specifically, suggesting its value for cancer diagnosis, antibody-drug conjugates, and potentially as a chimeric antigen receptor (CAR) for CLDN3-expressing pan-carcinoma.
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http://dx.doi.org/10.3390/biom10010051DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7022679PMC
December 2019

Phenotype-based discovery of a HeLa-specific cytotoxic molecule that downregulates HPV-mediated signaling pathways via oxidative damage.

Org Biomol Chem 2019 08;17(31):7388-7397

Center for Neuro-Medicine, Brain Science Institute, Korea Institute of Science and Technology, Seoul 02792, Korea.

Selective bioactive compounds have emerged as major players in chemical biology for their potential in disrupting diverse biological pathways with minimal adverse effects. Using phenotypic screening, we identified an anti-cancer agent, SB2001, with a highly specific cytotoxicity toward HeLa human cervical cancer cells. The subsequent mechanistic study revealed that SB2001 induced apoptotic cell death through restoring p53 function and suppressed the human papillomavirus (HPV)-mediated oncoprotein signaling pathway via oxidative damage in HeLa cells. SB2001 also selectively induced HeLa-specific tumor regression without any adverse effects in an in vivo tumor xenograft model, demonstrating its potential as a promising chemical probe.
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http://dx.doi.org/10.1039/c9ob01341eDOI Listing
August 2019

Development of an Equine Antitoxin by Immunizing the Halla Horse with the Receptor-Binding Domain of Botulinum Neurotoxin Type A1.

J Microbiol Biotechnol 2019 Jul;29(7):1165-1176

ABION Inc., R&D Center, Seoul 08394, Republic of Korea.

Botulinum neurotoxins (BoNTs), produced by , are the most toxic substances known. However, the number of currently approved medical countermeasures for these toxins is very limited. Therefore, studies on therapeutic antitoxins are essential to prepare for toxin-related emergencies. Currently, more than 10,000 Halla horses, a crossbreed between the native Jeju and Thoroughbred horses, are being raised in Jeju Island of Korea. They can be used for equine antitoxin experiments and production of hyperimmune serum against BoNT/A1. Instead of the inactivated BoNT/A1 toxoid, Halla horse was immunized with the receptor-binding domain present in the C-terminus of heavy chain of BoNT/A1 (BoNT/A1-HCR) expressed in . The anti-BoNT/A1-HCR antibody titer increased rapidly by week 4, and this level was maintained for several weeks after boosting immunization. Notably, 20 μL of the week 24 BoNT/A1-HCR(-immunized) equine serum showed an in vitro neutralizing activity of over 8 international unit (IU) of a reference equine antitoxin. Furthermore, 20 μL of equine serum and 100 μg of purified equine F(ab') showed 100% neutralization of 10,000 LD in vivo. The results of this study shall contribute towards optimizing antitoxin production for BoNT/A1, which is essential for emergency preparedness and response.
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http://dx.doi.org/10.4014/jmb.1904.04027DOI Listing
July 2019

A Glycoengineered Interferon-β Mutein (R27T) Generates Prolonged Signaling by an Altered Receptor-Binding Kinetics.

Front Pharmacol 2018 24;9:1568. Epub 2019 Jan 24.

Laboratory of Molecular Pathology and Cancer Genomics, Research Institute of Pharmaceutical Sciences and College of Pharmacy, Seoul National University, Seoul, South Korea.

The glycoengineering approach is used to improve biophysical properties of protein-based drugs, but its direct impact on binding affinity and kinetic properties for the glycoengineered protein and its binding partner interaction is unclear. Type I interferon (IFN) receptors, composed of IFNAR1 and IFNAR2, have different binding strengths, and sequentially bind to IFN in the dominant direction, leading to activation of signals and induces a variety of biological effects. Here, we evaluated receptor-binding kinetics for each state of binary and ternary complex formation between recombinant human IFN-β-1a and the glycoengineered IFN-β mutein (R27T) using the heterodimeric Fc-fusion technology, and compared biological responses between them. Our results have provided evidence that the additional glycan of R27T, located at the binding interface of IFNAR2, destabilizes the interaction with IFNAR2 via steric hindrance, and simultaneously enhances the interaction with IFNAR1 by restricting the conformational freedom of R27T. Consequentially, altered receptor-binding kinetics of R27T in the ternary complex formation led to a substantial increase in strength and duration of biological responses such as prolonged signal activation and gene expression, contributing to enhanced anti-proliferative activity. In conclusion, our findings reveal -glycan at residue 25 of R27T is a crucial regulator of receptor-binding kinetics that changes biological activities such as long-lasting activation. Thus, we believe that R27T may be clinically beneficial for patients with multiple sclerosis.
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http://dx.doi.org/10.3389/fphar.2018.01568DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6353837PMC
January 2019

Genes co-amplified with or as novel potential cancer-promoting genes in gastric cancer.

Oncotarget 2017 Nov 21;8(54):92209-92226. Epub 2017 Sep 21.

Laboratory of Molecular Pathology and Cancer Genomics, College of Pharmacy, Seoul National University, Seoul, Korea.

Gastric cancer (GC), one of the most common cancers worldwide, has a high mortality rate due to limited treatment options. Identifying novel and promising molecular targets is a major challenge that must be overcome if treatment of advanced GC is to be successful. Here, we used comparative genomic hybridization and gene expression microarrays to examine genome-wide DNA copy number alterations (CNAs) and global gene expression in 38 GC samples from old and young patients. We identified frequent CNAs, which included copy number gains on chromosomes 3q, 7p, 8q, 20p, and 20q and copy number losses on chromosomes 19p and 21p. The most frequently gained region was 7p21.1 (55%), whereas the most frequently deleted region was 21p11.1 (50%). Recurrent highly amplified regions 17q12 and 7q31.1-7q31.31 harbored two well-known oncogenes: and . Correlation analysis of CNAs and gene expression levels identified (co-amplified with ) and genes , , , and (co-amplified with ) as potential candidate cancer-promoting genes (CPGs). Public dataset analysis confirmed co-amplification of these genes with or in GC tissue samples, and revealed that high expression (except for ) was significantly associated with shorter overall survival. Knockdown of these genes using small interfering RNA led to significant suppression of GC cell proliferation and migration. Reduced GC cell proliferation mediated by knockdown was attributable to attenuated cell cycle progression and increased apoptosis. This study identified novel candidate CPGs co-amplified with or , and suggests that they play a functional role in GC.
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http://dx.doi.org/10.18632/oncotarget.21150DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5696175PMC
November 2017

MTA1 is a novel regulator of autophagy that induces tamoxifen resistance in breast cancer cells.

Autophagy 2018 15;14(5):812-824. Epub 2018 Jan 15.

a Department of Pharmacy, College of Pharmacy and Bio-MAX Institute , Seoul National University 1 Gwanak-ro , Gwanak-gu , Seoul , Korea.

Tamoxifen is commonly used to treat patients with ESR/ER-positive breast cancer, but its therapeutic benefit is limited by the development of resistance. Recently, alterations in macroautophagy/autophagy function were demonstrated to be a potential mechanism for tamoxifen resistance. Although MTA1 (metastasis-associated 1) has been implicated in breast tumorigenesis and metastasis, its role in endocrine resistance has not been studied. Here, we report that the level of MTA1 expression was upregulated in the tamoxifen resistant breast cancer cell lines MCF7/TAMR and T47D/TR, and knockdown of MTA1 sensitized the cells to 4-hydroxytamoxifen (4OHT). Moreover, knockdown of MTA1 significantly decreased the enhanced autophagy flux in the tamoxifen resistant cell lines. To confirm the role of MTA1 in the development of tamoxifen resistance, we established a cell line, MCF7/MTA1, which stably expressed MTA1. Compared with parental MCF7, MCF7/MTA1 cells were more resistant to 4OHT-induced growth inhibition in vitro and in vivo, and showed increased autophagy flux and higher numbers of autophagosomes. Knockdown of ATG7 or cotreatment with hydroxychloroquine, an autophagy inhibitor, restored sensitivity to 4OHT in both the MCF7/MTA1 and tamoxifen resistant cells. In addition, AMP-activated protein kinase (AMPK) was activated, probably because of an increased AMP:ATP ratio and decreased expression of mitochondrial electron transport complex components. Finally, publicly available breast cancer patient datasets indicate that MTA1 levels correlate with poor prognosis and development of recurrence in patients with breast cancer treated with tamoxifen. Overall, our findings demonstrated that MTA1 induces AMPK activation and subsequent autophagy that could contribute to tamoxifen resistance in breast cancer.
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http://dx.doi.org/10.1080/15548627.2017.1388476DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6070012PMC
October 2019

Polyamidoamine-Decorated Nanodiamonds as a Hybrid Gene Delivery Vector and siRNA Structural Characterization at the Charged Interfaces.

ACS Appl Mater Interfaces 2017 Sep 11;9(37):31543-31556. Epub 2017 Sep 11.

College of Pharmacy, Dongguk University-Seoul , Goyang, Gyeonggi 10326, Republic of Korea.

Nanodiamonds have been discovered as a new exogenous material source in biomedical applications. As a new potent form of nanodiamond (ND), polyamidoamine-decorated nanodiamonds (PAMAM-NDs) were prepared for E7 or E6 oncoprotein-suppressing siRNA gene delivery for high risk human papillomavirus-induced cervical cancer, such as types 16 and 18. It is critical to understand the physicochemical properties of siRNA complexes immobilized on cationic solid ND surfaces in the aspect of biomolecular structural and conformational changes, as the new inert carbon material can be extended into the application of a gene delivery vector. A spectral study of siRNA/PAMAM-ND complexes using differential scanning calorimetry and circular dichroism spectroscopy proved that the hydrogen bonding and electrostatic interactions between siRNA and PAMAM-NDs decreased endothermic heat capacity. Moreover, siRNA/PAMAM-ND complexes showed low cell cytotoxicity and significant suppressing effects for forward target E6 and E7 oncogenic genes, proving functional and therapeutic efficacy. The cellular uptake of siRNA/PAMAM-ND complexes at 8 h was visualized by macropinocytes and direct endosomal escape of the siRNA/PAMAM-ND complexes. It is presumed that PAMAM-NDs provided a buffering cushion to adjust the pH and hard mechanical stress to escape endosomes. siRNA/PAMAM-ND complexes provide a potential organic/inorganic hybrid material source for gene delivery carriers.
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http://dx.doi.org/10.1021/acsami.7b09624DOI Listing
September 2017

Effect of HPV E6/E7 siRNA with Chemotherapeutic Agents on the Regulation of TP53/E2F Dynamic Behavior for Cell Fate Decisions.

Neoplasia 2017 Oct 24;19(10):735-749. Epub 2017 Aug 24.

Research Institute of Pharmaceutical Science, College of Pharmacy, Seoul National University, Seoul 08826, Republic of Korea; The Center for Anti-cancer CDx, N-Bio, Seoul National University, Seoul 08826, Republic of Korea; Tumor Microenvironment Global Core Research Center, Seoul National University, Seoul 08826, Republic of Korea; Molecular Medicine and Biopharmaceutical Sciences, Graduate School of Convergence Science and Technology, Seoul National University, Seoul 08826, Republic of Korea. Electronic address:

Toxicity and resistance remain major challenges for advanced or recurrent cervical cancer therapies, as treatment requires high doses of chemotherapeutic agents. Restoration of TP53 and hypophosphorylated-retinoblastoma (pRB) proteins by human papillomavirus (HPV) E6/E7 siRNA sensitizes HPV-positive cervical cancer cells toward chemotherapeutic agents. Here, we investigated the therapeutic effects of E6/E7 siRNA on the dynamic behavior of TP53 and RB/E2F signaling networks in deciding the cell fate. The synergistic effect of HPV E6/E7 siRNA pool (SP) with chemotherapeutic agents on TP53 and RB/E2F signaling, proliferation, and apoptosis was analyzed in vitro and in vivo. Compared to the E6/E7 SP alone, E6/E7 SP with cisplatin treatment effectively restored TP53 and RB/E2F signaling and contributes to differences in cell fate, such as apoptosis or cell cycle arrest. We also developed a cellular dynamics model that includes TP53-RB/E2F dynamics and cell proliferation profiles, and confirmed its utility for investigating E6/E7 siRNA-based combination regimens. Using a dual reporter system, we further confirmed the cross talk between TP53 and RB/E2F signaling mechanisms. Treatment of E6/E7 SP cationic liposome (i.v.) with cisplatin and paclitaxel (i.p.) potentially inhibited tumor growth in BALB/c-nude mice. Altogether, our findings suggest that stabilization of TP53 and the RB/E2F repressor complex by E6/E7 SP combined with low-dose chemotherapy can effectively suppress tumor growth.
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http://dx.doi.org/10.1016/j.neo.2017.07.005DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5570578PMC
October 2017

Enhanced Cell Growth of Adipocyte-Derived Mesenchymal Stem Cells Using Chemically-Defined Serum-Free Media.

Int J Mol Sci 2017 Aug 16;18(8). Epub 2017 Aug 16.

Xcell Therapeutics, Hanhwa Biz Metro Building, 242 Digital-ro, Guro-gu, Seoul 152-733, Korea.

The multipotency and anti-inflammatory effects of mesenchymal stem cells (MSCs) make them attractive for cell therapy in regenerative medicine. A large number of MSCs is required for efficient therapy owing to the low homing efficiency of MSCs to target sites. Furthermore, owing to limitations in obtaining sufficient amounts of MSCs, in vitro expansion of MSCs that preserves their differentiation and proliferative potential is essential. The animal factor included in culture media also limits clinical application. In this study, adipose-derived MSCs showed a significantly higher proliferation rate in STK2, a chemically-defined medium, than in DMEM/FBS. The expression of MSC surface markers was increased in the culture using STK2 compared to that using DMEM/FBS. Tri-lineage differentiation analyses showed that MSCs cultured in STK2 were superior to those cultured in DMEM/FBS. In addition, MSCs cultured in STK2 showed a reduced senescence rate, small and homogenous cell size, and were more genetically stable compared to those cultured in DMEM/FBS. Furthermore, secretome analysis showed that the expression of factors related to proliferation/migration, anti-inflammation, and differentiation were increased in STK2 culture medium compared to DMEM/FBS. Taken together, these results suggest that culture using STK2 medium offers many advantages through which it is possible to obtain safer, superior, and larger numbers of MSCs.
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http://dx.doi.org/10.3390/ijms18081779DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5578168PMC
August 2017

Anticancer Efficacy of Ethanol Extract in a Xenografted Leukemia Model.

Evid Based Complement Alternat Med 2017 6;2017:8474703. Epub 2017 Jul 6.

Department of Genetic Engineering, Sungkyunkwan University, Suwon 16419, Republic of Korea.

is used widely as a traditional medicine in East Asia. Although a few studies have attempted to elucidate the anticancer activities of , the precise mechanism of therapeutic effects is not fully understood. We examined the anticancer activities of ethanolic extract (Cm-EE) and its cellular and molecular mechanisms. For this purpose, a xenograft mouse model bearing murine T cell lymphoma (RMA) cell-derived cancers was established to investigate in vivo anticancer mechanisms. MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay, immunoblotting analysis, and flow cytometric assay were employed to check in vitro cytotoxicity, molecular targets, and proapoptotic action of Cm-EE. Interestingly, cancer sizes and mass were reduced in a -administered group. Levels of the phosphorylated forms of p85 and AKT were clearly decreased in the group administered with Cm-EE. This result indicated that levels of phosphoglycogen synthase kinase 3 (p-GSK3) and cleaved caspase-3 were increased with orally administered Cm-EE. In addition, Cm-EE directly inhibited the viability of cultured RMA cells and C6 glioma cells. The number of proapoptotic cells was significantly increased in a Cm-EE treated group compared with a control group. Our results suggested that might be able to inhibit cancer growth through regulation of p85/AKT-dependent or GSK3-related caspase-3-dependent apoptosis.
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http://dx.doi.org/10.1155/2017/8474703DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5518515PMC
July 2017

MET Exon 14 Skipping Mutations in Lung Adenocarcinoma: Clinicopathologic Implications and Prognostic Values.

J Thorac Oncol 2017 08 10;12(8):1233-1246. Epub 2017 May 10.

Department of Thoracic and Cardiovascular Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea.

Introduction: Response to mesenchymal-epithelial transition (MET) inhibitors in NSCLC with mesenchymal-epithelial transition gene (MET) exon 14 skipping (METex14) has fueled molecular screening efforts and the search for optimal therapies. However, further work is needed to refine the clinicopathologic and prognostic implications of METex14 skipping.

Methods: Among 795 East Asian patients who underwent a surgical procedure for NSCLC, we screened 45 patients with quintuple-negative (EGFR-negative/KRAS-negative/anaplastic lymphoma kinase gene [ALK]-negative/ROS1-negative/ret proto-oncogene [RET]-negative) lung adenocarcinomas by using reverse-transcriptase polymerase chain reaction and found 17 patients (37.8%) with METex14 skipping. We also investigated the effect of small interfering RNA (siRNA) targeting skipping junction in cells with METex14 skipping.

Results: The median age of the 17 patients was 73 years. The acinar subtype was predominant (52.9%), followed by the solid subtype (35.3%). MET immunohistochemistry demonstrated 100% sensitivity and 70.4% specificity. Multivariate analyses showed that patients with METex14 skipping had a higher recurrence rate than those with ALK fusion (versus METex14 skipping) (hazard ratio = 0.283, 95% confidence interval: 0.119-0.670) in stage I to IIIA disease; however, the differences in overall survival were not significant after adjustment for pathologic stage (p = 0.669). Meanwhile, siRNA decreased MET-driven signaling pathways in Hs746T cells, and combined treatment with siRNA and crizotinib inhibited cell proliferation in crizotinib-resistant H596 cells.

Conclusions: The prevalence of METex14 skipping was quite high in East Asian patients without other driver mutations in lung adenocarcinomas. METex14 skipping was associated with old age, the acinar or solid histologic subtype, and high MET immunohistochemical expression. The prognosis of patients with METex14 skipping was similar to that of patients with major driver mutations. siRNA targeting the junction of METex14 skipping could inhibit MET-driven signaling pathways in cells with METex14 skipping.
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http://dx.doi.org/10.1016/j.jtho.2017.04.031DOI Listing
August 2017

Sensitization of glycoengineered interferon-β1a-resistant cancer cells by cFLIP inhibition for enhanced anti-cancer therapy.

Oncotarget 2017 Feb;8(8):13957-13970

College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul 08826, Republic of Korea.

In this study, we examined the molecular mechanism underlying the resistance of cancer cells to R27T, a glycoengineered version of recombinant human interferon (IFN)-β1a, and sought to overcome R27T resistance through combination therapy. R27T has been shown to induce anti-proliferation and apoptosis in human OVCAR-3 and MCF-7 cells, but not in HeLa cells. R27T treatment increased caspase-8 activity and the consequent cleavage of caspase-8 and -3 in R27T-sensitive OVCAR-3 cells, but not in R27T-resistant HeLa cells. Conversely, R27T increased the expression of cellular FLICE-like inhibitory protein (cFLIP) in HeLa cells, but not in OVCAR-3 cells. The sensitization of HeLa cells with cFLIP small interfering RNA or 4,5,6,7-tetrabromobenzotriazole (TBB, an inhibitor of casein kinase-2) facilitated R27T-induced caspase activation, and consequently apoptosis. In OVCAR-3-xenografted mice, intraperitoneal administration of R27T showed 2.1-fold higher anti-tumor efficacy than did the control vehicle. The combined administration of R27T and TBB showed the greatest anti-tumor effect in HeLa tumor-bearing mice, reducing the relative tumor volume by 35.7% compared to that in R27T-treated mice. Taken together, our results suggest that R27T has potential as an anti-cancer drug, and combination therapy with cFLIP inhibitors may be an effective strategy for overcoming R27T resistance.
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http://dx.doi.org/10.18632/oncotarget.14573DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5355153PMC
February 2017

Upregulation of SMAD4 by MZF1 inhibits migration of human gastric cancer cells.

Int J Oncol 2017 Jan 6;50(1):272-282. Epub 2016 Dec 6.

Research Institute of Pharmaceutical Science, Department of Pharmacy, College of Pharmacy, Seoul National University, Seoul, Republic of Korea.

SMAD4 is a tumor suppressor that is frequently inactivated in many types of cancer. The role of abnormal expression of SMAD4 has been reported in developmental processes and the progression of various human cancers. The expression level of SMAD4 has been related to the survival rate in gastric cancer patients. However, the molecular mechanism underlying transcriptional regulation of SMAD4 remains largely unknown. In the present study, we characterized the promoter region of SMAD4 and identified myeloid zinc finger 1 (MZF1), as a putative transcription factor. MZF1 directly bound to a core region of the SMAD4 promoter and stimulated transcriptional activity. We also found that the expression of MZF1 influences the migration ability of gastric adenocarcinoma cells. Collectively, our results showed that MZF1 has a role in cellular migration of gastric cancer cells via promoting an increase in intracellular SMAD4 levels. This study might provide new evidence for the molecular basis of the tumor suppressive effect of the MZF1-SMAD4 axis, a new therapeutic target in advanced human gastric cancer.
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http://dx.doi.org/10.3892/ijo.2016.3793DOI Listing
January 2017

LYN expression predicts the response to dasatinib in a subpopulation of lung adenocarcinoma patients.

Oncotarget 2016 Dec;7(50):82876-82888

Laboratory of Cancer Genomics and Molecular Pathology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.

Therapies targeting SRC family kinases (SFKs) have shown efficacy in treating non-small cell lung cancer (NSCLC). However, recent clinical trials have found that the SFK inhibitor dasatinib is ineffective in some patient cohorts. Regardless, dasatinib treatment may benefit some NSCLC patient subgroups. Here, we investigated whether expression of LYN, a member of the SFK family, is associated with patient survival, the efficacy of dasatinib, and/or NSCLC cell viability. LYN expression was associated with poor overall survival in a multivariate analysis, and this association was strongest in non-smoker female patients with adenocarcinoma (ADC). In lung ADC cells, LYN expression enhanced cell proliferation, migration, and invasion. Dasatinib inhibited LYN activity and decreased cell viability in LYN-positive ADC cell lines and xenografts. Additionally, we identified the SFKs SRC and YES as candidate dasatinib targets in LYN-negative ADC cell lines. Our findings suggest that LYN is a useful prognostic marker and a selective target of dasatinib therapy in the lung ADC subpopulation especially in female non-smokers with lung ADC.
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http://dx.doi.org/10.18632/oncotarget.12657DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5347739PMC
December 2016

and anti-inflammatory activities of Korean Red Ginseng-derived components.

J Ginseng Res 2016 Oct 24;40(4):437-444. Epub 2016 Aug 24.

Department of Genetic Engineering, Sungkyunkwan University, Suwon, Korea.

Background: Although Korean Red Ginseng (KRG) has been traditionally used for a long time, its anti-inflammatory role and underlying molecular and cellular mechanisms have been poorly understood. In this study, the anti-inflammatory roles of KRG-derived components, namely, water extract (KRG-WE), saponin fraction (KRG-SF), and nonsaponin fraction (KRG-NSF), were investigated.

Methods: To check saponin levels in the test fractions, KRG-WE, KRG-NSF, and KRG-SF were analyzed using high-performance liquid chromatography. The anti-inflammatory roles and underlying cellular and molecular mechanisms of these components were investigated using a macrophage-like cell line (RAW264.7 cells) and an acute gastritis model in mice.

Results: Of the tested fractions, KGR-SF (but not KRG-NSF and KRG-WE) markedly inhibited the viability of RAW264.7 cells, and splenocytes at more than 500 μg/mL significantly suppressed NO production at 100 μg/mL, diminished mRNA expression of inflammatory genes such as inducible nitric oxide synthase, cyclooxygenase-2, tumor necrosis factor-α, and interferon-β at 200 μg/mL, and completely blocked phagocytic uptake by RAW264.7 cells. All three fractions suppressed luciferase activity triggered by interferon regulatory factor 3 (IRF3), but not that triggered by activator protein-1 and nuclear factor-kappa B. Phospho-IRF3 and phospho-TBK1 were simultaneously decreased in KRG-SF. Interestingly, all these fractions, when orally administered, clearly ameliorated the symptoms of gastric ulcer in HCl/ethanol-induced gastritis mice.

Conclusion: These results suggest that KRG-WE, KRG-NSF, and KRG-SF might have anti-inflammatory properties, mostly because of the suppression of the IRF3 pathway.
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http://dx.doi.org/10.1016/j.jgr.2016.08.003DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5052440PMC
October 2016

Anti-Inflammatory and Antinociceptive Activities of Anthraquinone-2-Carboxylic Acid.

Mediators Inflamm 2016 3;2016:1903849. Epub 2016 Jan 3.

Department of Genetic Engineering, Sungkyunkwan University, Suwon 440-746, Republic of Korea.

Anthraquinone compounds are one of the abundant polyphenols found in fruits, vegetables, and herbs. However, the in vivo anti-inflammatory activity and molecular mechanisms of anthraquinones have not been fully elucidated. We investigated the activity of anthraquinones using acute inflammatory and nociceptive experimental conditions. Anthraquinone-2-carboxylic acid (9,10-dihydro-9,10-dioxo-2-anthracenecarboxylic acid, AQCA), one of the major anthraquinones identified from Brazilian taheebo, ameliorated various inflammatory and algesic symptoms in EtOH/HCl- and acetylsalicylic acid- (ASA-) induced gastritis, arachidonic acid-induced edema, and acetic acid-induced abdominal writhing without displaying toxic profiles in body and organ weight, gastric irritation, or serum parameters. In addition, AQCA suppressed the expression of inflammatory genes such as cyclooxygenase- (COX-) 2 in stomach tissues and lipopolysaccharide- (LPS-) treated RAW264.7 cells. According to reporter gene assay and immunoblotting analyses, AQCA inhibited activation of the nuclear factor- (NF-) κB and activator protein- (AP-) 1 pathways by suppression of upstream signaling involving interleukin-1 receptor-associated kinase 4 (IRAK1), p38, Src, and spleen tyrosine kinase (Syk). Our data strongly suggest that anthraquinones such as AQCA act as potent anti-inflammatory and antinociceptive components in vivo, thus contributing to the immune regulatory role of fruits and herbs.
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http://dx.doi.org/10.1155/2016/1903849DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4735930PMC
January 2017

The Role of Protein Arginine Methyltransferases in Inflammatory Responses.

Mediators Inflamm 2016 2;2016:4028353. Epub 2016 Mar 2.

Department of Genetic Engineering, Sungkyunkwan University, Suwon 440-746, Republic of Korea.

Protein arginine methyltransferases (PRMTs) mediate the methylation of a number of protein substrates of arginine residues and serve critical functions in many cellular responses, including cancer development, progression, and aggressiveness, T-lymphocyte activation, and hepatic gluconeogenesis. There are nine members of the PRMT family, which are divided into 4 types (types I-IV). Although most PRMTs do not require posttranslational modification (PTM) to be activated, fine-tuning modifications, such as interactions between cofactor proteins, subcellular compartmentalization, and regulation of RNA, via micro-RNAs, seem to be required. Inflammation is an essential defense reaction of the body to eliminate harmful stimuli, including damaged cells, irritants, or pathogens. However, chronic inflammation can eventually cause several types of diseases, including some cancers, atherosclerosis, rheumatoid arthritis, and periodontitis. Therefore, inflammation responses should be well modulated. In this review, we briefly discuss the role of PRMTs in the control of inflammation. More specifically, we review the roles of four PRMTs (CARM1, PRMT1, PRMT5, and PRMT6) in modulating inflammation responses, particularly in terms of modulating the transcriptional factors or cofactors related to inflammation. Based on the regulatory roles known so far, we propose that PRMTs should be considered one of the target molecule groups that modulate inflammatory responses.
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http://dx.doi.org/10.1155/2016/4028353DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4793140PMC
January 2017

Critical role of protein L-isoaspartyl methyltransferase in basic fibroblast growth factor-mediated neuronal cell differentiation.

BMB Rep 2016 Aug;49(8):437-42

Department of Genetic Engineering, Sungkyunkwan University, Suwon 16419, Korea.

We aimed to study the role of protein L-isoaspartyl methyltransferase (PIMT) in neuronal differentiation using basic fibroblast growth factor (bFGF)-induced neuronal differentiation, characterized by cell-body shrinkage, long neurite outgrowth, and expression of neuronal differentiation markers light and medium neurofilaments (NF). The bFGF-mediated neuronal differentiation of PC12 cells was induced through activation of mitogen-activated protein kinase (MAPK) signaling molecules [MAPK kinase 1/2 (MEK1/2), extracellular signal-regulated kinase 1/2 (ERK1/2), and p90RSK], and phosphatidylinositide 3-kinase (PI3K)/Akt signaling molecules PI3Kp110β, PI3Kp110γ, Akt, and mTOR. Inhibitors (adenosine dialdehyde and S-adenosylhomocysteine) of protein methylation suppressed bFGF-mediated neuronal differentiation of PC12 cells. PIMTeficiency caused by PIMT-specific siRNA inhibited neuronal differentiation of PC12 cells by suppressing phosphorylation of MEK1/2 and ERK1/2 in the MAPK signaling pathway and Akt and mTOR in the PI3K/Akt signaling pathway. Therefore, these results suggested that PIMT was critical for bFGF-mediated neuronal differentiation of PC12 cells and regulated the MAPK and Akt signaling pathways. [BMB Reports 2016; 49(8): 437-442].
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5070731PMC
http://dx.doi.org/10.5483/bmbrep.2016.49.8.020DOI Listing
August 2016

STAT3-mediated IGF-2 secretion in the tumour microenvironment elicits innate resistance to anti-IGF-1R antibody.

Nat Commun 2015 Oct 14;6:8499. Epub 2015 Oct 14.

College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 151 742, Korea.

Drug resistance is a major impediment in medical oncology. Recent studies have emphasized the importance of the tumour microenvironment (TME) to innate resistance, to molecularly targeted therapies. In this study, we investigate the role of TME in resistance to cixutumumab, an anti-IGF-1R monoclonal antibody that has shown limited clinical efficacy. We show that treatment with cixutumumab accelerates tumour infiltration of stromal cells and metastatic tumour growth, and decreases overall survival of mice. Cixutumumab treatment stimulates STAT3-dependent transcriptional upregulation of IGF-2 in cancer cells and recruitment of macrophages and fibroblasts via paracrine IGF-2/IGF-2R activation, resulting in the stroma-derived CXCL8 production, and thus angiogenic and metastatic environment. Silencing IGF-2 or STAT3 expression in cancer cells or IGF-2R or CXCL8 expression in stromal cells significantly inhibits the cancer-stroma communication and vascular endothelial cells' angiogenic activities. These findings suggest that blocking the STAT3/IGF-2/IGF-2R intercellular signalling loop may overcome the adverse consequences of anti-IGF-1R monoclonal antibody-based therapies.
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http://dx.doi.org/10.1038/ncomms9499DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4608384PMC
October 2015

CD4⁺ T cells play a crucial role for lenalidomide in vivo anti-tumor activity in murine multiple myeloma.

Oncotarget 2015 Nov;6(34):36032-40

Department of Lymphoma/Myeloma, Division of Cancer Medicine, University of Texas MD Anderson Cancer Center, Houston, TX, United States.

Lenalidomide modulates the host immune response against myeloma via multiple actions. Although these effects have been elucidated in vitro, the central action of lenalidomide-mediated anti-myeloma immune response in vivo is not clear. To investigate its immune action in vivo, we selected the murine myeloma cell line 5TGM1, which is resistant to direct tumoricidal effects of lenalidomide in vitro and in immunodeficient mice, but sensitive to lenalidomide treatment in 5TGM1-bearing immunocompetent mice. Depletion of CD4+ T cells, but not NK cells, B cells, or CD8+ T cells, deprived lenalidomide of its therapeutic effects on 5TGM1-bearing immunocompetent mice. Lenalidomide significantly increased the numbers of IFN-γ-secreting CD4+ and CD8+ T cells but had no effects on NK cells and B cells in this mouse model. Lenalidomide slightly decreased the number of CD25+Foxp3+ T cells but increased perforin expression in CD8+ T cells in vivo. Using this mouse model for investigation of anti-tumor immune action of lenalidomide, we demonstrated that lenalidomide facilitated a type-1 anti-tumor immune response in vivo. The CD4+ T cell subset may play a critical role in the lenalidomide-mediated anti-myeloma immune response in vivo.
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http://dx.doi.org/10.18632/oncotarget.5506DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4742159PMC
November 2015

AKT-independent Reelin signaling requires interactions of heterotrimeric Go and Src.

Biochem Biophys Res Commun 2015 Nov 9;467(4):1063-9. Epub 2015 Oct 9.

Department of Anatomy, Ajou University School of Medicine, Suwon 16499, South Korea; Center for Cell Death Regulating Bio-drug, Ajou University School of Medicine, Suwon 16499, South Korea. Electronic address:

Reelin, a large secreted extracellular matrix glycoprotein, plays a key role in neuronal migration during cortical development and promotes neuronal maturation. The signaling pathway regulating neuronal maturation in the postnatal period are relatively less well understood. In this study, we demonstrated that a heterotrimeric G protein, Go, is a novel target of Reelin-induced signaling to promote neurite outgrowth. In primary hippocampal neurons of Reelin-deficient reeler mice, neurite outgrowth was significantly reduced and rescued upon addition of Reelin. Pertussis toxin (PTX) treatment or transfection with Gαo-siRNA suppressed Reelin-mediated neurite outgrowth in wild-type neurons. Additionally, Reelin treatment led to increased phosphorylation of AKT, GSK3β, and JNK, which were all effectively blocked by the PI3K inhibitor, LY294002. By comparison, PTX specifically blocked JNK activation, but not AKT and GSK3β. Immunoprecipitation assays disclosed that Reelin increases the active forms of both Src and Gαo and promotes their direct association. Notably, Dab1, a cytoplasmic adaptor molecule that mediates Reelin signaling, did not interact with Gαo. Neurite outgrowth by Reelin was induced via activating Src kinase, which directly stimulated Gαo, activity, leading to JNK activation. Based on the collective findings, we suggest that Reelin-dependent signaling mechanisms may be split into Src-AKT-dependent and Src-Go-dependent pathways. Our results additionally provide evidence that Reelin receptors cross-communicate with heterologous G protein-coupled receptors (GPCR) independently of the cognate ligands of GPCR.
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http://dx.doi.org/10.1016/j.bbrc.2015.09.167DOI Listing
November 2015

TBK1 inhibitors: a review of patent literature (2011 - 2014).

Expert Opin Ther Pat 2015 19;25(12):1385-96. Epub 2015 Aug 19.

c 3 Sungkyunkwan University, Department of Genetic Engineering , 300 Chuncheon-Dong, Suwon 440-746, Korea +82 312 907 868 ; +82 312 907 870 ;

Introduction: TANK-binding kinase 1 (TBK1) is a noncanonical IκB kinase family member that regulates the innate immune response. Misregulation of TBK1 activity can promote inflammatory disorders and oncogenesis; therefore, TBK1 inhibitors are considered a promising therapy for inflammation and cancer.

Areas Covered: In this review, the authors provide information on the role of TBK1 in human health and on recently developed inhibitors from patents granted from 2011 to 2014. The reader will gain an understanding of the mechanisms of TBK1 function as well as the structure and biological activity of recently developed TBK1 inhibitors. Google and NCBI search engines were used to find relevant patents and clinical information using "TBK1 inhibitor" as the search term.

Expert Opinion: The role of TBK1 in various diseases has prompted the further investigation of significant targets. Although research on TBK1 inhibitors has increased over the last few years, only a few inhibitors of this kinase have been identified. In addition, almost all of the chemical inhibitors are modified from different scaffolds and/or chemotypes of pyrimidine. Specifically, compound BX795 is the representative one, which was first patented as a potent TBK1 inhibitor. Even though some compounds have displayed interesting potential inhibition and selectivity of TBK1 in vitro and in in vivo trials, the development of more efficient and selective TBK1 inhibitors is still required.
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http://dx.doi.org/10.1517/13543776.2015.1081168DOI Listing
July 2016

Immunotoxicological Effects of Aripiprazole: In vivo and In vitro Studies.

Korean J Physiol Pharmacol 2015 Jul 30;19(4):365-72. Epub 2015 Jun 30.

Department of Genetic Engineering, Sungkyunkwan University, Suwon 440-746, Korea.

Aripiprazole (ARI) is a commonly prescribed medication used to treat schizophrenia and bipolar disorder. To date, there have been no studies regarding the molecular pathological and immunotoxicological profiling of aripiprazole. Thus, in the present study, we prepared two different formulas of aripiprazole [Free base crystal of aripiprazole (ARPGCB) and cocrystal of aripiprazole (GCB3004)], and explored their effects on the patterns of survival and apoptosis-regulatory proteins under acute toxicity and cytotoxicity test conditions. Furthermore, we also evaluated the modulatory activity of the different formulations on the immunological responses in macrophages primed by various stimulators such as lipopolysaccharide (LPS), pam3CSK, and poly(I:C) via toll-like receptor 4 (TLR4), TLR2, and TLR3 pathways, respectively. In liver, both ARPGCB and GCB3004 produced similar toxicity profiles. In particular, these two formulas exhibited similar phospho-protein profiling of p65/nuclear factor (NF)-κB, c-Jun/activator protein (AP)-1, ERK, JNK, p38, caspase 3, and bcl-2 in brain. In contrast, the patterns of these phospho-proteins were variable in other tissues. Moreover, these two formulas did not exhibit any cytotoxicity in C6 glioma cells. Finally, the two formulations at available in vivo concentrations did not block nitric oxide (NO) production from activated macrophage-like RAW264.7 cells stimulated with LPS, pam3CSK, or poly(I:C), nor did they alter the morphological changes of the activated macrophages. Taken together, our present work, as a comparative study of two different formulas of aripiprazole, suggests that these two formulas can be used to achieve similar functional activation of brain proteins related to cell survival and apoptosis and immunotoxicological activities of macrophages.
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http://dx.doi.org/10.4196/kjpp.2015.19.4.365DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4499649PMC
July 2015

Pro-Apoptotic Activity of 4-Isopropyl-2-(1-Phenylethyl) Aniline Isolated from Cordyceps bassiana.

Biomol Ther (Seoul) 2015 Jul 1;23(4):367-73. Epub 2015 Jul 1.

Department of Genetic Engineering, Sungkyunkwan University, Suwon 440-746.

Cordyceps species including Cordyceps bassiana are a notable anti-cancer dietary supplement. Previously, we identified several compounds with anti-cancer activity from the butanol fraction (Cb-BF) of Cordyceps bassiana. To expand the structural value of Cb-BF-derived anti-cancer drugs, we employed various chemical moieties to produce a novel Cb-BF-derived chemical derivative, KTH-13-amine-monophenyl [4-isopropyl-2-(1-phenylethyl) aniline (KTH-13-AMP)], which we tested for anti-cancer activity. KTH-13-AMP suppressed the proliferation of MDA-MB-231, HeLa, and C6 glioma cells. KTH-13-AMP also dose-dependently induced morphological changes in C6 glioma cells and time-dependently increased the level of early apoptotic cells stained with annexin V-FITC. Furthermore, the levels of the active full-length forms of caspase-3 and caspase-9 were increased. In contrast, the levels of total forms of caspases-3, caspase-8, caspase-9, and Bcl-2 were decreased in KTH-13-AMP treated-cells. We also confirmed that the phosphorylation of STAT3, Src, and PI3K/p85, which is linked to cell survival, was diminished by treatment with KTH-13-AMP. Therefore, these results strongly suggest that this compound can be used to guide the development of an anti-cancer drug or serve as a lead compound in forming another strong anti-proliferative agent.
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http://dx.doi.org/10.4062/biomolther.2015.021DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4489832PMC
July 2015
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