• Journal of Life Science
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• v.15 no.6 s.73
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• pp.895-903
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• 2005

Thrombospondin-1 (TSP-1), a negative regulator in tumor growth and angiogenesis, is cell-type specifically regulated under pathological conditions or by extracellular stimuli, and the regulation of TSP-1 gene expression is important for developing new approaches in tumor therapy. Mistletoe is a parasitir plant that have been used for immunomodulation and antitumor therapy. Helixor A is an aqueous part of mistletoes extract. Here we showed that TSP-1 expression was significantly induced at both mRNA and protein levels in the Hepatocarcinorna cell line (Hep3B) and primary bovine endothelial cell line (BAE) exposed to Helixor A. Our promoter analysis confirmed that the expression of TSP-1 gene was regulated by Helixor A at the transcriptional level. In cell invasion assay, the conditioned media obtained from treatment of these cells significantly reduced the number of invasive cells and also inhibited capillary-like tube formation of BAE cells on Matrigel. Moreover, the inhibitory efforts of the conditioned media on cell invasion and tube formation were reversed by blocking with anti-TSP-1 neutralizing antibodies, suggesting that TSP-1 is involved in Helixor A-indured antiangiogenic effect. Taken together, our results suggest that Helixor A have an antiangiogenic effects through upregulation of TSP-1.

• International Journal of Oral Biology
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• v.34 no.4
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• pp.177-183
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• 2009

Human mesenchymal stem cell (hMSCs) isolated from human adult bone marrow have self-renewal capacity and can differentiate into multiple cell types in vitro and in vivo. A number of studies have now demonstrated that MSCs can differentiate into various neuronal populations. Due to their autologous characteristics, replacement therapy using MSCs is considered to be safe and does not involve immunological complications. The basic helix-loop-helix (bHLH) transcription factor Olig2 is necessary for the specification of both oligodendrocytes and motor neurons during vertebrate embryogenesis. To develop an efficient method for inducing neuronal differentiation from MSCs, we attempted to optimize the culture conditions and combination with Olig2 gene overexpression. We observed neuron-like morphological changes in the hMSCs under these induction conditions and examined neuronal marker expression in these cells by RTPCR and immunocytochemistry. Our data demonstrate that the combination of Olig2 overexpression and neuron-specific conditioned medium facilitates the neuronal differentiation of hMSCs in vitro. These results will advance the development of an efficient stem cell-mediated cell therapy for human neurodegenerative diseases.

• Biomolecules & Therapeutics
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• v.13 no.3
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• pp.143-149
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• 2005

We have demonstrated previously on a replication incompetent recombinant adenoviral vector, AdLPCD, in which the expression of cytosine deaminase (CD) gene is driven by the tumor-specific L-plastin promoter. The object of this study was to evaluate the efficacy of AdLPCD together with 5-fluorocytosine (5-FC) in suppression of the growth of established human tumor cells of ovary, Consistent with the knowledge that infection of OVCAR-3 cells with AdLPCD resulted in expression of a functional intracellular CD enzyme capable of converting 5-FC to 5-fluorouracil (5-FU) (Chung and Deisseroth, 2004), statistically significant differences in cytotoxicity were observed when AdLPCD infected cells were also exposed to 5-FC for 6 days (p=0.05), 9 days (p<0.0005) and 12 days (p<0.005), compared to 5-FC exposure alone, These results indicate that the CD gene delivered by adenoviral vector could efficiently sensitize OVCAR-3, otherwise non-toxic 5-FC. On the other hand, SKOV-3 cells, an ovarian carcinoma cell line, were more resistant to the CD/5-FC strategy compared with OVCAR-3 cells under the same condition. The results of present study suggest that the replacement of 5-FU with CD/5-FC in combination chemotherapy would be less toxic and much greater cytotoxicity than the conventional combination chemotherapy in some patients.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.12
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• pp.7489-7496
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• 2013

This study was conducted to investigate enhancement of anti-tumor effects of the lentogenic Newcastle disease virus Clone30 strain (NDV rClone30) expressing cytosine deaminase (CD) gene against tumor cells and in murine groin tumor-bearing models. Cytotoxic effects of the rClone30-CD/5-FC on the HepG2 cell line were examined by an MTT method. Anti-tumor activity of rClone30-CD/5-FC was examined in H22 tumor-bearing mice. Compared to the rClone30-CD virus treatment alone, NDV rClone30-CD/5-FC at 0.1 and 1 MOIs exerted significant cytotoxic effects (P<0.05) on HepG2 cells. For treatment of H22 tumor-bearing mice, recombinant NDV was injected together with 5-FC given by either intra-tumor injection or tail vein injection. When 5-FC was administered by intra-tumor injection, survival for the rClone30-CD/5-FC-treated mice was 4/6 for 80 days period vs 1/6, 0/6 and 0/6 for the mice treated with rClone30-CD, 5-FC and saline alone, respectively. When 5-FC was given by tail vein injection, survival for the rClone30-CD/5-FC-treated mice was 3/6 vs 2/6, 0/6 and 0/6 for the mice treated with rClone30-CD, 5-FC or saline alone, respectively. In this study, NDV was used for the first time to deliver the suicide gene for cancer therapy. Incorporation of the CD gene in the lentogenic NDV genome together with 5-FC significantly enhances cell death of HepG2 tumor cells in vitro, decreases tumor volume and increases survival of H22 tumor-bearing mice in vivo.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.9
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• pp.4815-4822
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• 2012

Invasion and metastasis are the major causes of cancer-related death. Pharmacological or therapeutic interventions such as chemoprevention of the progression stages of neoplastic development could result in substantial reduction in the incidence of cancer mortality. (-)-Epigallocatechin-3-gallate (EGCG), a promising chemopreventive agent, has attracted extensive interest for cancer therapy utilizing its antioxidant, anti-proliferative and inhibitory effects on angiogenesis and tumor cell invasion. In this study, we assessed the influence of EGCG on the proliferative potential of HeLa cells by cell viability assay and authenticated the results by nuclear morphological examination, DNA laddering assay and cell cycle analysis. Further we analyzed the anti-invasive properties of EGCG by wound migration assay and gene expression of MMP-9 and TIMP-1 in HeLa cells. Our results indicated that EGCG induced growth inhibition of HeLa cells in a dose- and time-dependent manner. It was observed that cell death mediated by EGCG was through apoptosis. Interestingly, EGCG effectively inhibited invasion and migration of HeLa cells and modulated the expression of related genes (MMP-9 and TIMP-1). These results indicate that EGCG may effectively suppress promotion and progression stages of cervical cancer development.

• Genomics & Informatics
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• v.19 no.1
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• pp.2.1-2.10
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• 2021

BRAF inhibitors (e.g., vemurafenib) are widely used to treat metastatic melanoma with the BRAF V600E mutation. The initial response is often dramatic, but treatment resistance leads to disease progression in the majority of cases. Although secondary mutations in the mitogen-activated protein kinase signaling pathway are known to be responsible for this phenomenon, the molecular mechanisms governing acquired resistance are not known in more than half of patients. Here we report a genome- and transcriptome-wide study investigating the molecular mechanisms of acquired resistance to BRAF inhibitors. A microfluidic chip with a concentration gradient of vemurafenib was utilized to rapidly obtain therapy-resistant clones from two melanoma cell lines with the BRAF V600E mutation (A375 and SK-MEL-28). Exome and transcriptome data were produced from 13 resistant clones and analyzed to identify secondary mutations and gene expression changes. Various mechanisms, including phenotype switching and metabolic reprogramming, have been determined to contribute to resistance development differently for each clone. The roles of microphthalmia-associated transcription factor, the master transcription factor in melanocyte differentiation/dedifferentiation, were highlighted in terms of phenotype switching. Our study provides an omics-based comprehensive overview of the molecular mechanisms governing acquired resistance to BRAF inhibitor therapy.

• IMMUNE NETWORK
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• v.4 no.3
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• pp.190-197
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• 2004

Background: Rheumatoid arthritis (RA) is an autoimmune disorder characterized by chronic synovial inflammation which leads to joint destruction. Gene therapy of RA targets the players of inflammation or articular destruction. However, viral vectors have safety problems and side effects, while non-viral vectors suffer from inefficient gene transfer and fast loss of gene expression. To overcome the limits of non-vial vectors, an EBV-based plasmid which is known to exert prolonged high level gene expression can be used. Methods: pEBVGFP, pEBVIL-10, and pEBVvIL-10 were constructed by cloning GFP, IL-10, and vIL-10 genes into an EBV-based plasmid, respectively. The pGFP was used as a control plasmid. Each constructs were lipofected into HIG-82 rabbit synoviocytes. The expression of GFP was monitored by FACS and confocal microscopy. IL-10 and vIL-10 expressions were measured by ELISA. Results: GFP expression 2 days after transfection was achieved in 33.2% of cells. GFP-expressing cells transfected with pGFP decreased rapidly from 4 days after transfection and disappeared completely by 11 days. Cells transfected with pEBVGFP began to decrease slowly from 4 days. But GFP expression was detected for over 35 days. In addition, HIG-82 cells transfected with pEBVIL-10 ($44.6{\pm}1.5ng/ml$) or pEBVvIL-10 ($51.0{\pm}5.7ng/ml$) secreted these cytokines at high levels. High level cytokine production by hygromycin selection was maintained at least for up to 26 days after transfection. Conclusion: These results suggest that the EBV-based plasmid has a potential to improve non-viral gene transfer system and may be applicable to treat RA without the drawbacks of viral vectors.

• Molecules and Cells
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• v.42 no.3
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• pp.237-244
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• 2019

Understanding the mechanisms of cancer drug resistance is a critical challenge in cancer therapy. For many cancer drugs, various resistance mechanisms have been identified such as target alteration, alternative signaling pathways, epithelial-mesenchymal transition, and epigenetic modulation. Resistance may arise via multiple mechanisms even for a single drug, making it necessary to investigate multiple independent models for comprehensive understanding and therapeutic application. In particular, we hypothesize that different resistance processes result in distinct gene expression changes. Here, we present a web-based database, CDRgator (Cancer Drug Resistance navigator) for comparative analysis of gene expression signatures of cancer drug resistance. Resistance signatures were extracted from two different types of datasets. First, resistance signatures were extracted from transcriptomic profiles of cancer cells or patient samples and their resistance-induced counterparts for >30 cancer drugs. Second, drug resistance group signatures were also extracted from two large-scale drug sensitivity datasets representing ~1,000 cancer cell lines. All the datasets are available for download, and are conveniently accessible based on drug class and cancer type, along with analytic features such as clustering analysis, multidimensional scaling, and pathway analysis. CDRgator allows meta-analysis of independent resistance models for more comprehensive understanding of drug-resistance mechanisms that is difficult to accomplish with individual datasets alone (database URL: http://cdrgator.ewha.ac.kr).

• Microbiology and Biotechnology Letters
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• v.47 no.3
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• pp.449-458
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• 2019

Hepatitis B treatments using immune therapy are gaining interest because of the improvements in dendritic cell performance for antigen presentation, which induces an appropriate immune response and raises patient survival rates. This research aims to produce a significant amount of the HBcAg antigen, which can induce an immune response and have a curative effect on HBV infection. In this study, the HBV subgenotype B3 of the HBcAg gene was used, which is dominant in Indonesia. Further, Lactococcus lactis bacteria was used as the host because of its safety and tightly regulated protein expression. The codon usage for the HBcAg gene was optimized to improve protein expression in L. lactis, which is important because a codon is not random between species. The HBcAg gene is attached to a pNZ8148 plasmid and transformed into the L. lactis NZ3900 expression host. The results confirm that a positive protein band (21 kDa) in two fractions of purified HBcAg was recognized by both western blotting and dot blot hybridization, even if the HBcAg optimized codon has higher GC contents than that suggested for L. lactis expression. Overall, this research strengthens the broad use of L. lactis bacteria for any protein expression, including higher protein expression of codon optimized HBcAg gene compared to non-optimized genes. Furthermore, the improvement in the codon optimization of the HBcAg gene significantly increases the total protein expression by 10-20%, and the expression level of the codon optimized HBcAg increases 1.5 to 3.2-times that of the native HBcAg.

• Korean Journal of Head & Neck Oncology
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• v.22 no.2
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• pp.130-136
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• 2006

Introduction : The sensitivity of tumor cells to radiotherapy is a critical determinant of local control and potential cure in advanced head and neck squamous cell carcinoma(HNSCC). The emergence of radioresistant tumor cells is an obstacle to cancer therapy. Most radioresistant cells have a higher proportion of cells in the Sphase of the cell cycle and a lower apoptotic fraction than radiosensitive cells. HSV replication is increased in cells that have higher S-phase fractions. NV1066 is an oncolytic herpes simplex virus type-1 mutant. We hypothesized that NV1066 replication and cytotoxicity are increased in radioresistant cells. The purpose of this study is to evaluate the antitumor efficacy of NV1066 to treat radioresistant HNSCC. Methods : Radioresistant cells were selected by treating five HNSCC cell lines with repeated conventional fractionated doses of radiation(2Gy/day), using a Cs-137 irradiator, up to a cumulative dose of 70Gy. Clonogenic cell survival and S-phase fractions were compared between radioresistant and parental radiosensitive cells. The two cell populations were then treated with NV1066 to examine viral replication, by the viral plaque assay and viral cytotoxicity. Results : Fractionated irradiation resulted in the selection of radioresistant cells. Radioresistant cells had a higher S-phase fraction(42.9%) compared to parental cells(26.2%). NV1066 replication in radioresistant cells was 7.4 times higher than in parental cells(p<0.01). Treatment with NV1066 resulted in increased cytotoxicity of 24.5% in radioresistant cells compared to parental cells(p<0.05). Conclusion : NV1066 showed increased viral replication and cytotoxicity in radioresistant HNSCC cell lines. These findings suggest a potential clinical application for this oncolytic viral therapy as treatment for radioresistant head and neck cancers.