• 한국환경성돌연변이발암원학회지
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• 제16권2호
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• pp.103-108
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• 1996

The mutagenic potential of rHu-EPO was evaluated using the short-term genotoxicity tests including Ames, chromosome aberration and micronuclei tests. In Salmonella typhimurium assay, rHu-EPO did not show any mutagenic response in the absence or presence of S9 mix with TA98, TA100, TA1535, and TA1537. In chromosome aberration test, rHu-EPO did not show any significant effect on Chinese Hamster Ovary(CHO) cells compared with control. In micronucleus test using male ICR mice, a dose-dependence increase in the frequency of micronucleuted polychromatic erythrocytes(MNPCEs) was observed in bone marrow cells treated with rHu-EPO. However, it was related to the secondary effect of rHu-EPO and the number of MNPCEs was equal to spontaneous frequency. These results indicate that rHu-EPO does not show any positive response in short-term genotoxicity assays.

• 한국식품위생안전성학회지
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• 제1권1호
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• pp.13-21
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• 1986

Two short-term bioassays were employed to asses the mutagenic and clastogenic activities in browning reaction of pentose-creatine, pentose-glycine and pentose-creatine-glycine browning reaction model system. Methylene chloride extract of rhamnose-creatine-glycine browning reaction exhibited the strongest mutagenicity toward Salmonella typhimurium TA98 with S-9. Methylene chloride extract of pentose-creatine and pentose-glycine browning reaction solutions was also tested for mutagenicity, with positive responses. Methylene chloride extract of pentose-creatine-glycine browning reaction solutions induced significant increase in chromosome aberrations in the treated Chinese hamster ovary(CHO) cells. Each of pentose-creatine and pentose-glycine browning reaction solutions induced a relatively low frequency of chromosome aberrations in the treated cells.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2002년도 생물공학의 동향 (X)
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• pp.53-56
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• 2002

Mammalian cell based biosensor kits are expected to be in assessment of samples toxicity more sensitive and accurate. A recombinant fluorescent Chinese Hamster Ovary (CHO) cell line was known to be responsive to the various toxicants Specially. KFC- AlO cell line. which contain the c-fos SRE::GFP plasmid (pKFG). was found to be able to detect toxicants sensitively. A biosensor kit was developed by using an immobilized KFC-A10 cell line. Immobilized recombinant fluorescent cells within agarose, known as a representative hydrogel matrix, have been maintained in the matrix viably and have shown constant fluorescent levels for long time. Immobilized cells have shown the ability to detect the chemical toxicity in the keep of fluorescent level as the metabolism is inhibited under toxic conditions.

• Toxicological Research
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• 제20권2호
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• pp.153-158
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• 2004

To evaluate the genotoxicity of CJ-11555, an anti-cirrhotic agent, the reverse mutation test, chromosomal aberration test and in vivo micronucleus test in rats were performed. In the reverse mutation test, the treatment of CJ-11555 at doses of 33.3, 100, 333, 1000, 3330 and 5000 $\mu\textrm{g}$/plate with and without 89 did not induce mutagenicity in Salmonella typhimurium TA98, TA100, TA1535, TA1537, and Escherichia coli (E. call) WP2uvrA. In chromosomal aberration test, CJ-11555 did not induce structural a chromosomal aberration in Chinese hamster ovary (CHO) cells with and without metabolic activation at all doses. In micronucleus test, CJ-11555 did not induce any statistically significant increases in micronucleated polychromatic erythrocyte (MNPCE) at doses of 500, 1000, and 2000 mg/kg. These results suggest that CJ-11555 might not have a mutagenic potential under the conditions in this study.

• 한국환경성돌연변이발암원학회지
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• 제9권2호
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• pp.63-72
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• 1989

본 연구는 N-methyl-N'-nitro-N-nitrosoguanidine(MNNG) 를 처리한 CHO-K1세포에서 DNA 복제억제와 그 회복과정의 분자론적 기작을 규명할 목적으로 방사선 이중표지에 의한 DNA합성율의 측정, 알카리 자당농도구배 초원심분리법에 의한 DNA 분자량과 후복제 회복율을 측정하여 다음과 같은 결과를 얻었다. DNA 합성율은 2nM 이하의 낮은 농도의 MNNG 처리군에서는 급격히 감소하였으나, 5nM 이상의 농도에서는 그 감소양상이 둔화되었다. 억제되었던 DNA 합성율은 시간경과에 따라 회복되어 처리 후 4시간 째에는 대조군 수준 또는 그 이상으로 회복되었다. MNNG 처리 후 DNA 분자 크기의 분포와 새로 합성된 DNA 분자의 생장양상을 알카리 자당농도구배 초원심분리법으로 조사한 결과 MNNG 처리 후 시간 경과에 따라 새로합성된 DNA 분자들의 크기분포는 1*107 달톤 이하의 DNA 분자들의 합성양이 특이하게 증가하였다가 감소함을 보였다.

• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-2
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• pp.120.1-120.1
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• 2003

The mutagenic potential of Gryllus bimaculatus was evaluated using the short-term genotoxicity tests including Ames, chromosome aberration and micronuclei tests. In salmonella typhimurium assay, G. bimaculatus did not show any mutagenic response in the absence or presence of S9 mix with TA98, TAl00, TA1535, and TA1537. In chromosome aberration test, G. bimaculatus did not show any significant effect on Chinese Hamster Ovary (CHO) cells compared with control. (omitted)

• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-2
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• pp.170.3-171
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• 2003

An efficient Erythropoietin (EPO)-expression system in mammalian cells is required for massive production for therapeutic use. Ammonium ion is a major problem in the production of valuable recombinant proteins in cultured animal cells. Therefore, it is of importance to devise a system by which a high productivity of human therapeutic recombinant protein can be maintained or enhanced under low ammonium concentration. To reduce the ammonium ion accumulated in EPO producing Chinese Hamster Ovary (CHO) ceels, IBE, we introduced the first two genes of the urea cycle, carbamoyl phosphate synthetase (CPSI) and arnithine transcarbamoylase (OTC), into IBE using a stable transfection method. (omitted)

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2002년도 생물공학의 동향 (X)
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• pp.261-264
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• 2002

CHO (Chinese hamster ovary) cells were transfected with plasmids containing both cis-acting HRE (hypoxia response element) and CMV-promoter that controls tissue-type plasminogen activator (t-PA). CHO cells with HRE produced 16.2 fold higher t-PA concentration than CHO cells without HRE. It was noted that hypoxia strongly induced CHO cell apoptosis. which resulted in decrease of cell viability and protein production. In this study. by introducing Bcl-2, anti-apoptotic gene, we tried to recover cell viability and increase the protein production. When batch culture of both control cells without transfection of Bcl-2 and cells transfected with Bcl-2 were performed in the absence of CoCl ι hypoxia mimic condition. the cells with Bcl-2 were effected specific cell growth rates, maximum cell density. Immunoblotting assay showed Bcl-2 was recombinant with HRE dependent t- P A expression cassette, and their expression level was depended on hypoxia. By introducing Bcl-2, both cell viability and maximum cell density could be increased.

• Journal of Microbiology and Biotechnology
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• 제13권6호
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• pp.926-936
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• 2003

Overexpression of human Bcl-2 protein in recombinant Chinese hamster ovary (rCHO) cells producing humanized antibody (SH2-0.32) considerably suppressed sodium butyrate (NaBu)-induced apoptosis during batch culture by using commercially available serum-free medium, which extended the culture longevity. Due to the extended culture longevity provided by the anti-apoptotic effect of Bcl-2 overexpression, the final antibody concentration of 14C6-bcl-2 culture (Bcl-2 high producer, $23\;\mu\textrm{g}\;ml^{-1}$) was 2 times higher than that of the $SH2-0.32-{\Delta}bcl-2$ culture (cells transfected with bcl-2-deficient plasmid, $10.5\;\mu\textrm{g}\;ml^{-1}$) in the presence of NaBu. To determine the effect of NaBu/Bcl-2 overexpression on the molecular integrity of protein products, antibodies purified from 14C6-bcl-2 and $SH2-0.32-{\Delta}bcl-2$ cultures in the presence of NaBu were characterized by using various molecular assay systems. For comparison, antibody purified from the parental rCHO cell culture (SH2-0.32) in the absence of NaBu was also characterized. No significant changes in molecular weight of antibodies could be observed by SDS-PAGE. From GlycoSep-N column analysis, it was found that the core oligosaccharide structure ($GlcNAc_2Man_3GlcNAc_2$) was not affected by NaBu/Bcl-2 overexpression, while the microheterogeneity of N-linked oligosaccharide structure was slightly affected. Compared with the antibody produced in the absence of NaBu, the proportion of neutral oligosaccharides was increased from 10% (14C6-bcl-2) to 16% ($SH2-0.32-{\Delta}bcl-2$) in the presence of NaBu, which was accompanied by the reduced proportion of acidic oligosaccharides, especially of monosialylated and disialylated forms. The changes in microheterogeneous oligoformal structures of antibody in turn affected the mobility of antibody isoforms in isoelectric focusing (IEF), resulting in the occurrence of some more basic antibody isoforms produced in the presence of NaBu. However, the antigen-antibody binding properties were not changed by alteration of glycosylation pattern. The competitive enzyme-linked immunosorbent assay (ELISA) showed that the antibody produced by NaBu/Bcl-2 overexpression maintained its antigen-antibody binding properties with binding affinity of about $2.5{\times}10^9{\;}M^{-1}$. Taken together, no significant effects of NaBu/Bcl-2 overexpression on the molecular integrity of antibodies, produced by using serum-free medium, could be observed by the molecular assay systems.

• 대한의생명과학회지
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• 제14권4호
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• pp.203-210
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• 2008

One of cell surface receptor proteins, human folate receptor (hFR) involves in the uptake of folates through cell membrane into cytoplasm, and is anchored to the plasma membrane by a fatty acid linkage, which has been identified in some cells as a glycosylphosphatidylinositol (GPI)-tailed protein with a molecular mass of about 40 kDa. The hFR is released by phosphatidylinositol phospholipase C (PI-PLC) because it contains fatty acids and inositol on the GPI tail. Caveolin decorates the cytoplasmic surface of caveolae and has been proposed to have a structural role in maintaining caveolae. It is unknown whether caveolin is involved in targeting, and is necessary for the function of GPI-tailed proteins. To compare the ability of folic acid binding, internalization and expression of hFR, and the effect of caveolin at the both apical and basolateral side of cell surfaces in Chinese hamster ovary (CHO) clone cells overexpressed the hFR and/or caveolin. Our present results suggest a possibility that the overexpression of caveolin does not be involved in expression of hFR, but plays a role as a factor in PI-PLC releasing kinetics, and for a regulation of formation, processing and function of hFR in CHO clone cells overexpressed cavcolin.