• Korean Journal of Environmental Biology
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• v.26 no.1
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• pp.30-35
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• 2008

In order to investigate whether or not CCD-986sk cell line can be affected by Korean Ecklonia stolonifera Okamura, we examined the MTT assay when we treated Korean Ecklonia stolonifera Okamura extract in CCD-986sk human fibroblast cell line. The sample were tested for cell proliferation activity by means of a modification of the MTT assay. Ecklonia stolonifera Okamura extract showed significantly strong cell proliferation activity at the range of from 6.25 mg $mL^{-1}$ to 1.56 mg $mL^{-1}$ compared with control group. And in order to search for inhibition agents of skin melanin formation, we tested for inhibition effect of melanin pigmentation of Korean Ecklonia stolonifera Okamura using Clone M-3 mouse melanocyte cell lines. when we treated the extracts of Ecklonia stolonifera Okamura to the mouse melanocyte cell lines, the sample showed a significantly little formation of melanin pigments compared with control group at the only range of 200 mg $mL^{-1}$. These results suggest that extract of Korean Ecklonia stolonifera Okamura may represents an excellent candidate for inhibition of melanin pigmentation and for protection of human skin aging at in vitro level.

• Journal of Microbiology and Biotechnology
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• v.14 no.4
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• pp.810-815
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• 2004

Many biological properties and the clinical potential of human interleukin-2 (hIL-2) draw much attention to its high-level expression in mammalian cells. Recombinant human IL-2 (rhIL-2) was expressed in Chinese hamster ovary (CHO) cells, using the recently developed expression system which confers position-independent expression. Stable CHO cell lines carrying several hundred amplified copies of the rhIL-2 gene were easily obtained and rhIL-2 was expressed at high levels after selection with increasing concentrations of methotrexate. Interestingly, the insertion of the transcription terminator of the human gastrin gene into the downstream region of the gene for rhIL-2 considerably increased rhIL-2 expression. Using the expression system with the transcription terminator, it was possible to get a CHO cell line expressing the rhIL-2 at a very high level, about $11.4\mug/10^6$ cell/day, which is about 6 times higher than that previously reported. The biological activity of the rhIL-2 protein purified from the cell line was also confirmed by the cell proliferation assay.

• Journal of Microbiology
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• v.37 no.2
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• pp.86-89
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• 1999

An OTHBVS cell line from HepG2 was established. This cell line stably expresses the human hepatitis B virus (HBV) middle S protein that includes the preS2 region which is important for HBV particle entry into the hepatocyte. To establish this cell line, the middle S open reading frame (ORF), with a promoter located in the 5' region and enhancer located in the 3' region, was cloned downstream from the metallothionine (MT) promoter of the OT1529 vector. In this vector, expression of the middle S protein was constructed to be regulated by its own promoter and enhancer. Expression of the large S protein which contains the preS1 region in addition to the middle S protein was designed to be regulated by the MT promoter. When extracts of OTHBVS cells were examined with an S protein detection kit (RPHA, Korea Green Cross Co.), an S protein was detected. Total mRNA of OTHBVS cell examined by northern blot analysis with an S ORF probe revealed small/middle S transcripts (2.1 kb). When the MT promoter was induced by Zn, large S transcripts (2.4 kb) were detected. The GP36 and GP33 middle S proteins were presumably detected, but large S proteins were not detected by immunostain analysis using anti-preS2 antibody.

• Journal of Pharmacopuncture
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• v.20 no.3
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• pp.207-212
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• 2017

Objectives: Study of the mechanisms involved in cancer progression suggests that cyclooxygenase enzymes play an important role in the induction of inflammation, tumor formation, and metastasis of cancer cells. Thus, cyclooxygenase enzymes could be considered for cancer chemotherapy. Among these enzymes, cyclooxygenase 2 (COX-2) is associated with liver carcinogenesis. Various COX-2 inhibitors cause growth inhibition of human hepatocellular carcinoma cells, but many of them act in the COX-2 independent mechanism. Thus, the introduction of selective COX-2 inhibitors is necessary to achieve a clear result. The present study was aimed to determine the growth-inhibitory effects of new analogues of chalcone epoxide as selective COX-2 inhibitors on the human hepatocellular carcinoma (HepG2) cell line. Methods: Estimation of both cell growth and the amount of prostaglandin E2 (PGE2) production were used to study the effect of selective COX-2 inhibitors on the hepatocellular carcinoma cell. Cell growth determination has done by MTT assay in 24 h, 48 h and 72 h, and PGE2 production has estimated by using ELYSA kit in 48 h and 72 h. Results: The results showed growth inhibition of the HepG2 cell line in a concentration and time-dependent manner, as well as a reduction in the formation of PGE2 as a product of COX-2 activity. Among the compounds those analogues with methoxy and hydrogen group showed more inhibitory effect than others. Conclusion: The current in-vitro study indicates that the observed significant growth-inhibitory effect of chalcone-epoxide analogues on the HepG2 cell line may involve COX-dependent mechanisms and the PGE2 pathway parallel to the effect of celecoxib. It can be said that these analogues might be efficient compounds in chemotherapy of COX-2 dependent carcinoma specially preventing and treatment of hepatocellular carcinomas.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.373.2-373.2
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• 2002

In search for plant-derived cytotoxic compounds, it was found that the MeOH extracts obtained from Amanita pantherina(DC. ex Fr.) Krombh exhibited significant cytotoxic activity against human tumor cell line. The classical fractionation on the basis of the inhibitory activity upon the growth human tumor cell line. in vitro, and repeated column chromatography afforded several cytotoxic compounds from Amanita pantherina (DC, ex Fr.) Krombh. (omitted)

• Biomedical Science Letters
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• v.15 no.1
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• pp.37-45
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• 2009

Insect cell cultures have become important tools in the production of biological substances for use in a variety of research, human and veterinary medicine, and pest control applications. These applications often require the introduction of foreign DNA into the cells and have generally used methods originally developed for use with human and other mammalian cell cultures. While these methods can be successfully employed, they are often less efficient with insect cells and frequently involve complex procedures or require specialized equipment. Even when they do work, they may require substantial modification because of differences in the culture medium or growth patterns of insect cells. In this study, We have optimized transfection conditions of Sf9 cell line using insect expression vector pIZT/V5-His which expresses green fluorescent protein effectively. Human stem cell factor (hSCF) is a glycoprotein that plays a key role in hematopoiesis acting both as a positive and negative regulator, often in synergy with other cytokines. It also plays a key role in mast cell development, gametogenesis, and melanogenesis. It can exist in membrane-bound form and in proteolytically released soluble form. As determined by an enzyme-linked immunosorbent assay performed, hSCF level in supernatant averaged 995ng/ml. The human hSCF was partially purified by immunoaffinity chromatography and analyzed with sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting. The results show that the hSCF has N-linked carbohydrate and corresponds to the soluble form, at or about 223 amino acids in length. The findings suggest functional importance for soluble hSCF in cells.

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.66-69
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• 2001

Previously we developed a CHO cell line (CHO-OTC1-A19) expressing the first two enzymes of urea cycle. This cell line showed higher ammonia removal activity and faster growth rate than the vector controlled CHO cells (CHO-neo-5). The purpose of this study was to develop a cell line with higher ammonia removal activity than the cell line developed previously. To accomplish this, we constructed stable CHO cell lines expressing the first three, the first four, or all five enzymes of urea cycle by the stable transfection method. We finally selected CHO-AL-19 cell line expressing the first three, the first four enzymes of the cycle with higher ammonia activity than CHO-OTC1-A19 and CHO-n대-5 cell lines: 40% and 15% higher than those of CHO-neo-5 and CHO-OTC1-A19 cell lines 72 hour after culture started, respectively. It also showed 44% and 10% higher cell viability than CHO-neo-5 and CHO- OTC1-A19 cell lines at higher cell density. In addition, CHO-AL-19 cells showed 45%-60% and about 20% lower ammonia concentration per cell than those of CHO-neo-% and CHO-OTC1-A19 cell lines, respectively. These results indicate that CHO-AL-19 could be used in the production of human therapeutic proteins with higher efficiency.

• Bulletin of the Korean Chemical Society
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• v.34 no.5
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• pp.1503-1507
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• 2013

The two major symptoms characterizing Alzheimer's disease are the formation of amyloid-${\beta}$ extracellular deposits in the form of senile plaques and intracellular neurofibrillary tangles (NFTs) that consist of pathological hyperphosphorylated tau protein aggregated into insoluble paired helical filaments (PHFs). Neurons of the central nervous system have appreciable amounts of tau protein, a microtubule-associated protein. To maintain an optimal operation of nerves, the microtubules are stabilized, which is necessary to support cell structure and cellular processes. When the modified tau protein becomes dysfunctional, the cells containing misfolded tau cannot maintain cell structure. One of the pathological hallmarks of Alzheimer's disease is hyperphosphorylated tau protein. This paper shows that the small heat shock protein from humans (Hsp27) reduces hyperphosphorylated tau and prevents hyperphosphorylated tau-induced cell death of the human neuroblastoma cell line SH-SY5Y.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.246.1-246.1
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• 2002

We studied the effects of ursodeoxycholic acid (UDCA) and its synthetic derivatives. HS-l030 and HS-1183. and chenodeoxycholic acid (CDCA) and its synthetic derivatives, HS-1199 and HS-1200. on the human colon adenocarcinoma cell line. HT -29 (p53 mutant type). The effects on cell viability and growth were assessed by MTT assay and cell growth study. While UDCA and CDCA exhibited no significant effect, their novel derivatives inhibited the proliferation of HT-29 cell line in a concentration- and time-dependent manners. (omitted)

• Journal of The Korean Radiological Technologist Association
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• v.30 no.1
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• pp.70-76
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• 2004

To evaluate the process of radiation-induced cell damage in human promyelocytic leukemia cell HL-60 cell and chinese hamster cell CHO cell lines. I irradiated HL-60 cells, CHO cell line, using the V - radiation from Cs-137 cell irradiation(Gamma cell 3000