• 한국생물공학회:학술대회논문집
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• 2005.04a
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• pp.233-233
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• 2005

• Proceedings of the Korea Society of Design Studies Conference
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• 2001.10a
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• pp.8.2-8
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• 2001

• Molecules and Cells
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• v.43 no.11
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• pp.953-963
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• 2020

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is an infectious disease with multiple severe symptoms, such as fever over 37.5℃, cough, dyspnea, and pneumonia. In our research, microRNAs (miRNAs) binding to the genome sequences of severe acute respiratory syndrome coronavirus (SARS-CoV), Middle East respiratory-related coronavirus (MERS-CoV), and SARS-CoV-2 were identified by bioinformatic tools. Five miRNAs (hsa-miR-15a-5p, hsa-miR-15b-5p, hsa-miR-195-5p, hsa-miR-16-5p, and hsa-miR-196a-1-3p) were found to commonly bind to SARS-CoV, MERS-CoV, and SARS-CoV-2. We also identified miRNAs that bind to receptor proteins, such as ACE2, ADAM17, and TMPRSS2, which are important for understanding the infection mechanism of SARS-CoV-2. The expression patterns of those miRNAs were examined in hamster lung samples infected by SARS-CoV-2. Five miRNAs (hsa-miR-15b-5p, hsa-miR-195-5p, hsa-miR-221-3p, hsa-miR-140-3p, and hsa-miR-422a) showed differential expression patterns in lung tissues before and after infection. Especially, hsa-miR-15b-5p and hsa-miR-195-5p showed a large difference in expression, indicating that they may potentially be diagnostic biomarkers for SARS-CoV-2 infection.

• Journal of Environmental Health Sciences
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• v.41 no.6
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• pp.405-411
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• 2015

Objectives: The purpose of this study is to evaluate the optimum conditions for oral mucosal irritation testing using the buccal pouch of hamsters. Methods: Test materials were applied to the buccal pouch of seven-week old male Syrian hamsters (SLC, Japan) four times at one-hour intervals and macroscopic changes were examined at 24 hours after final treatment. After sacrifice, the buccal pouches were removed and prepared for histopathological evaluation. In order to set the exposure time, we performed exposure tests of 5, 12, 18 and 23 minutes using sodium lauryl sulfate (SLS) 1% and set the treatment volume from the test results at 2, 3, or 4 ml treatment using SLS 1%, Triton X-100 1% and ethanol. After setting the experimental conditions, seven groups of materials [sodium lauryl sulfate (SLS) (1%), Triton X-100 (1%), hydrogen peroxide (3%), ethanol (100%), chlorhexidine (0.2%, 2%), phosphate buffer saline (PBS)] were assessed. Results: Experimental conditions of material exposure time were fixed as 18 minutes from the exposure tests of 5, 12, 18 or 23 min using sodium lauryl sulfate (SLS) 1%. Treated volume was set as 4 ml per each pouch from the test results of 2, 3, or 4 ml treatments using SLS 1%, Triton X-100 1% and ethanol. The results in terms of irritation degree were in the order of sodium lauryl sulfate (SLS) (1%) > Triton X-100 (1%) ${\fallingdotseq}$ hydrogen peroxide (3%) > ethanol (100%) ${\fallingdotseq}$ chlorhexidine (0.2%, 2%) > phosphate buffer saline (PBS). Conclusion: From this study, suitable conditions for hamster mucosal irritation testing were suggested and this method was verified through materials commonly used on oral mucosal membranes.

• Environmental Mutagens and Carcinogens
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• v.24 no.2
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• pp.99-107
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• 2004

The validation of many synthetic chemicals that may pose a genetic hazard in our environment is of great concern at present. Since these substances are not limited to the original products, and enter the environment, they have become widespread environmental pollutants, thus leading to a variety of chemicals that possibly threaten the public health. In this respect, the regulation and evaluation of the chemical hazard playa very important role to environment and human health. The clastogenicity of 11 synthetic chemicals was evaluated in Chinese hamster lung (CHL) fibroblast in vitro. Benzoyl chloride (CAS No. 98-88-4) induced chromosomal aberrations with statistical significance at the concentration of 31-123 $\mug/ml$ and 43 $\mug/ml$ in the absence and presence of S-9 metabolic activation system, respectively. 2-Propyn-l-o1 (CAS No. 107-19-7) and 2-Phenoxy ethanol (CAS No. 122-99-6) revealed clastogenicity only at the highest concentration in the presence of S-9 mixture. However, 1-naphthol (CAS No. 90-15-3) which is one of the most cytotoxic chemical among 11 chemicals tested revealed no clastogenicity both in the presence and absence of S-9 metabolic activation system. From the results of chromosomal aberration assay with 11 synthetic chemicals in CHL fibroblast in vitro, Benzoyl chloride (CAS No. 98-88-4), 2-Propyn-l-01 (CAS No. 107-19-7) and 2-Phenoxy ethanol (CAS No. 122-99-6) revealed positive clastogenic results in this study.

• Biotechnology and Bioprocess Engineering:BBE
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• v.11 no.4
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• pp.319-324
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• 2006

Although the sera used in animal cell culture media provide the macromolecules, nutrients, hormones, and growth factors necessary to support cell growth, it could also be an obstacle to the production of recombinant proteins in animal cell culture systems used in many sectors of the biotechnology industry. For this reason, many research groups, including our laboratory, have been trying to develop serum-free media (SFM) or serum-supplemented media (SSM) for special or multi-purpose cell lines. The Chinese hamster ovary (CHO) cell, for example, is frequently used to produce proteins and is especially valuable in the large-scale production of pharmaceutically important proteins, yet information about its genome is lacking. Also, SFMs have only been evaluated by comparing growth patterns for cells grown in SFMs with those grown in SSM or by measuring the titer of the target protein obtained from cells grown in each type of medium. These are not reliable methods of obtaining the type of information needed to determine whether an SFM should be replaced with an SSM. We carried out a cDNA microarray analysis to evaluate MED-3, an SFM developed in our laboratory, as a CHO culture medium When CHO cells were cultured in MED-3 instead of an SSM, several genes associated with cell growth were down-regulated, although this change diminished over time. We found that the insulin-like growth factor (IGF) gene was representative of the proteins that were down-regulated in cells cultured in MED-3. When several key supplements - including insulin, transferrin, ethanolamine, and selenium - were removed from MED-3, the IGF expression was consistently down- regulated and cell growth decreased proportionately. Based on these results, we concluded that when an SFM is used as a culture medium, it is important to supplement it with substances that can help the cells maintain a high level of IGF expression. The data presented in this study, therefore, might provide useful information for the design and development of SFM or SSM, as well as for the design of genome-based studies of CHO cells to determine how they can be used optimally for protein production in pharmaceutical and biomedical research.

• Microbiology and Biotechnology Letters
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• v.34 no.1
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• pp.47-51
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• 2006

Sodium butyrate (NaBu) is used as an enhancer for the production of recombinant proteins in Chinese hamster ovary (CHO) cells. However, NaBu is well-known for its cytotoxic effect, thereby inducing apoptosis. CHO cells which had been engineered to express a humanised anti-HBV antibody were cultured using serum-free medium, Ex-cell 301. From a seeding density of $2{\times}10^5$ cells/ml, CHO cells grown with serum-free medium reached a maximum cell density of $1.3{\times}10^6$ cells/ml after 9 days in culture and produced a maximal antibody concentration of 130 mg/l after 13 days in culture. In the perfusion culture system, CHO cells producing anti-HBV antibody grown in an 7.5 1 bioreactor seeded with $2{\times}10^5$ cells/ml reached a maximal antibody concentration of 85 mg/1 after 720 h in culture. The addition of 0.3 mM NaBu and lowering culture temperature to $33^{\circ}C$ elongated the culture period to 60 days and increased the production yield by 2-fold, compared to control culture.

• Journal of Microbiology and Biotechnology
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• v.23 no.8
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• pp.1116-1122
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• 2013

Cell line development is the most critical and also the most time-consuming step in the production of recombinant therapeutic proteins. In this regard, a variety of vector and cell engineering strategies have been developed for generating high-producing mammalian cells; however, the cell line engineering approach seems to show various results on different recombinant protein producer cells. In order to improve the secretory capacity of a recombinant tissue plasminogen activator (t-PA)-producing Chinese hamster ovary (CHO) cell line, we developed cell line engineering approaches based on the ceramide transfer protein (CERT) and X-box binding protein 1 (XBP1) genes. For this purpose, CERT S132A, a mutant form of CERT that is resistant to phosphorylation, and XBP1s were overexpressed in a recombinant t-PA-producing CHO cell line. Overexpression of CERT S132A increased the specific productivity of t-PA-producing CHO cells up to 35%. In contrast, the heterologous expression of XBP1s did not affect the t-PA expression rate. Our results suggest that CERT-S132A-based secretion engineering could be an effective strategy for enhancing recombinant t-PA production in CHO cells.

• Environmental Mutagens and Carcinogens
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• v.16 no.1
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• pp.19-23
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• 1996

This study was performed by the sister chromatid exchanges (SCEs) and micronuclei (MN) assays to investigate the adaptive response to ultraviolet light (UV) or ethyl methanesulfonate (EMS) in Chinese hamster ovary (CHO) and Sarcoma 180 (S180) cells. The pretreatment with 1 J/m$^2$ UV or 2 mM EMS decreased the frequency of SCEs induced by the treatment with 5 J/m$^2$ UV or 8 mM EMS in CHO cells. The pretreatment with UV (1 or 2 J/m$^2$) or EMS (1, 2 or 3 mM) did not affect the SCEs induced by the treatment with 7 J/m$^2$ UV or 10 mM EMS in S180 cells. On the other hand, the pretreatment with 1 J/m$^2$ UV or 2 mM EMS decreased the frequency of MN induced by the treatment with 5 J/m$^2$ UV or 8 mM EMS in CHO cells. The pretreatment with UV (1 or 2 J/m$^2$) or EMS (1, 2 or 3 mM) did not affect the frequency of MN induced by the treatment with 7 J/m$^2$ UV or 10 mM EMS in S180 cells. It is suggested that there are adaptive responses at the level of chromosome and micronuclei to UV and EMS in CHO cells.

• Parasites, Hosts and Diseases
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• v.26 no.1
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• pp.9-14
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• 1988

In an attempt to determine the susceptibility of inbred golden hamsters(Mesocricetus auratus) to the experimental infection with Clonorchis sinensis, twenty-five hamsters were divided into 5 groups and administered orally 5, 10, 20, 30 or 50 metacercariae each. The hamsters were killed on the 45th day after infection. The adult flukes were recovered from all hamsters. The overall recovery rate for the fluke was 57.9% with the range of 48.4% to 92.0%. As the number of the metacercariae given increased, a porportionate decrease in the recovery rate was found, the prepatent period of the fluke in the hamster varied from 15 to 17 days, with the average of 16 days. No significant differences in the development of the flukes were observed. Egg production expressed by EPG, increased step by step as the time elapsed. However, a tendency of decreasing egg laying capacity was observed with the increase of worm burden. It is suggested that the hamster is a suitable final host of C. sinensis.