• 생명과학회지
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• 제13권5호
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• pp.712-717
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• 2003

박테리오신의 일종인 leucocin A를 생산하는 효모의 제작을 위하여 117 bp 길이의 개시코돈과 종지코돈을 포함하는 leucocin A 유전자를 합성하여 효모운반체인 pAUR123에 클로닝하였다. 형질전환된 효모는 부패균의 일종인 고초균(Bacillus subtilis)에 대해 항균활성을 나타냈다. 형질전환 효모로부터 분리한 플라스미드를 주형으로 하고 leucocin A에 특이적인 primer들을 이용하여 PCR 반응을 행한 결과, 효모에 도입된 leucocin A 유전자를 확인할 수 있었다. 이 연구의 결과로 부패하기 쉬운 식품들의 보존성을 향상시키거나, 내성이 생긴 병원균의 생육을 저해하기 위한 항생제로 사용할 수 있는 박테리오신을 산업적으로 생산할 수 있는 효모세포를 제작하였다.

• 식물조직배양학회지
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• 제24권4호
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• pp.225-231
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• 1997

For genetic engineering to be commercially viable, an efficient transformation system is needed to produce transgenic plane from diverse genotypes ("generalized protocol"). Development of such a system requires optimization of a number of components such as gene transfer agent, plant tissues competent for both regeneration and transformation, and control of transgene expression. Although several novel gene transfer methods have been developed for plane, a majority of stably transformed plane express the introduced genes at low levels. Moreover, silencing of selectable marker genes shortly after their incorporation into plant chromosomes may result in low recovery of transgenic tissues from selection. Matrix attachment regions (MARs) are DNA sequences that bind to the cell's proteinaceous nuclear matrix to form DNA loop domains. MARs have been shown to increase transgene expression in tobacco cells, and reduce position in mature transgenic plants. Flanking an antibiotic resistance transgene with MARs should therefore lead to improved rates of transformation in a diversity of species, and may permit recalcitrant species and genotypes to be successfully transformed. Literature review and recent data from my laboratory suggest that MARs can serve as a transformation booster in recalcitrant plant species.

• 한국독성학회:학술대회논문집
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• 한국독성학회 2001년도 International Symposium on Dietary and Medicinal Antimutgens and Anticarcinogens
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• pp.157-157
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• 2001

One of the most frequent defects in human cancer is the uncontrolled activation of the ras-signaling pathways. We have previously shown that H-ras, but not N-ras, induces an invasiveness and motility in human breast epithelial cells (MCF10A), while both H-ras and N-ras induce transformed phenotype. Since migration plays a crucial role in invasive, we examined motility of MCF10A cells transformed with H-ras of N-ras.(omitted)

• Journal of Plant Biology
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• 제36권1호
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• pp.75-81
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• 1993

Ginseng (Panax ginseng C.A. Meyer) hairy root transformed with Agrobacterium rhizogenes (strain A4) was examined cytogenetically and histologically to assess its characteristics. The optimum growth of hairy root obtained in hormone-free MS medium (sucrose 30 g/L, pH5-6) for long period cultures. All hairy root strains (HB1, HB2, HB3) had the 2n diploid number (2n=48) of chromosomes in root tip cells. There were no alteration in chromosome structure except in one cell of HB3 strain. Results of SDS-PAGE showed a few difference in pattern and number of bands between normal and hairy root of ginseng. The root anatomy of normal root and hairy root differed each other. The hairy root had a clearly defined vascular strand, and the morphology of cortical cells were disorganised with large intercellular spaces.

• Natural Product Sciences
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• 제10권3호
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• pp.129-133
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• 2004

Quercetin is a dietary anticancer chemical that is capable of inducing apoptosis in tumor cells. However, little is known about its biological effect in nonmalignant hepatic cells. Using embryonic normal hepatic cell line (BNL CL.2) and its SV40-transformed tumorigenic cell line (BNL SV A.8), we evaluated the effects of quercetin on cell proliferation and apoptosis. As the results, our present study demonstrated that quercetin had a selective growth inhibition in normal versus tumorigenic hepatic cells such that BNL SV A.8 cells were very sensitive to the quercetin-mediated cytotoxicity. In particular, as evidenced by the increased number of positively stained cells in the TUNEL assay, the induction of characteristic nuclear DNA ladders, and the migration of many cells to sub-G1 phase in the BNL SV A.8 cells, quercetin treatment more sensitively induced apoptosis in BNL SV A8 cells than in BNL CL.2 cells. Collectively, our findings suggest that quercetin can be approached as a potential agent that is capable of inducing selective growth inhibition and apoptosis of hepatic cancer cells.

• Archives of Pharmacal Research
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• 제27권1호
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• pp.61-67
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• 2004

When ginseng water extract was incubated at $60^{\circ}C$ in acidic conditions, its protopanaxadiol ginsenosides were transformed to ginsenoside $Rg_3$ and ${\Delta}^{20}$-ginsenoside $Rg_3$. However, protopanaxadiol glycoside ginsenosides $Rb_1, Rb_2$ and Rc isolated from ginseng were mostly not transformed to ginsenoside $Rg_3$ by the incubation in neutral condition. The transformation of these ginsenosides to ginsenoside $Rg_3$ and ${\Delta}^{20}$-ginsenoside $Rg_3$ was increased by increasing incubation temperature and time in acidic condition: the optimal incubation time and temperature for this transformation was 5 h and $60^{\circ}C$ resepectively. The transformed ginsenoside $Rg_3$ and ${\Delta}^{20}$-ginsenoside $Rg_3$ were metabolized to ginsenoside $Rh_2$ and $\Delta^{20}$--ginsenoside $Rh_2$, respectively, by human fecal microflora. Among the bacteria isolated from human fecal microflora, Bacteroides sp., and Bifidobacterium sp. and Fusobacterium sp. potently transformed ginsenoside $Rg_3$ to ginsenoside $Rh_2$. Acid-treated ginseng (AG) extract, fermented AG extract, ginsenoside $Rh_2$ and protopanaxadiol showed potent cytotoxicity against tumor cell lines. AG extract, fermented AG extract and protopanaxadiol potently inhibited the growth of Helicobacter pylori.

• Archives of Pharmacal Research
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• 제25권6호
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• pp.903-909
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• 2002

Research in the cytokine field has grown exponentially in recent years, and the validity of such studies relies heavily on the appropriate measurement of levels of cytokines in various biological samples. Transforming growth factor (TGF)-$\beta$, a hormonally active polypeptide found in normal and transformed tissue, is a potent regulator of cell growth and differentiation. The most widely used bioassay for TGF-$\beta$ is the inhibition of the proliferation of mink lung epithelial cells. Though detection of [$^3$H]thymidine incorporation is more sensitive than the MTT assay, it presents some disadvantages due to the safety and disposal problems associated with radioisotopes. In this study, we attempted to ascertain the experimental conditions which could be used for measuring the in vitro biological activity of TGF-$\beta$ in a safer and more sensitive way compared with the currently available methods. We compared the commonly used method, the MTT assay, to the XTT assay using different parameters including cell number, incubation time and the wave length used for detecting the product. We examined the anti-proliferative activities of TGF-$\beta$ in three different cell lines: Mv-1-Lu mink lung epithelial cells, MCF10A human breast epithelial cells and H-ras-transformed MCF10A cells. Herein, we present an experimental protocol which provides the most sensitive method of quantifying the biological activity of TGF-$\beta$, with a detection limit of as low as 10 pg/ml: Mv-1-Lu or H-ras MCF10A cells ($1{\times}10^5/well$) were incubated with TGF-$\beta$ at $37^{\circ}C$ in a humidified $CO_2$ incubator for 24 hr followed by XTT treatment and determination of absorbance at 450 or 490 nm. Our results may contribute to the establishment of an in vitro bioassay system, which could be used for the satisfactory quantitation of TGF-$\beta$.

• BMB Reports
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• 제45권3호
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• pp.200-205
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• 2012

Enzymatic oxidation of commercially available pyrogallol was efficiently transformed to an oxidative product, purpurogallin. Purpurogallin plays an important role in inhibiting glutathione S-transferase, xanthine oxidase, catechol O-methyltransferase activities and is effective in the cell protection of several cell types. However, the anti-inflammatory functions of purpurogallin are not well studied. Here, we determined the effects of purpurogallin on lipopolysaccharide (LPS)-mediated proinflammatory responses. The results showed that purpurogallin inhibited LPS-mediated barrier hyper-permeability, monocyte adhesion and migration and such inhibitory effects were significantly correlated with the inhibitory functions of purpurogallin on LPS-mediated cell adhesion molecules (vascular cell adhesion molecules, intracellular cell adhesion molecule, E-selectin). Furthermore, LPS-mediated nuclear factor-${\kappa}B$ (NF-${\kappa}B$) and tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$) releases from HUVECs were inhibited by purpurogallin. Given these results, purpurogallin showed its anti-inflammatory activities and could be a candidate as a therapeutic agent for various systemic inflammatory diseases.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2001년도 The 8th International Symposium
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• pp.49-58
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• 2001

We tried to introduce two forsythia genes related in lignan biosynthesis, dirigent protein and pinoresinol/lariciresinol (P/L) reductase, into potatoes for accumulation of lignans in transgenic potatoes. We made binary vectors overexpressing dirigent protein gene and P/L reductase gene driven by a CaMV35S promoter and transformed into potatoes via Agrobacterium mediated transformation. And in order to control the metabolic flux of lignan biosynthesis pathway, we tried to inhibit chalcone synthase genes of potatoes by antisense inhibition technique also. We tried to use PCR screening method for selection of transgenic plants of different vectors. We tried to determine and compare lignan contents from different transgenic potato lines.

• 한국미생물·생명공학회지
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• 제21권1호
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• pp.59-65
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• 1993

방선균 분리주 GMT 1153로부터 ts/NRK 세포의 형태를 변형된 세포형태에서 정상세포의 형태로 전환하는 활성물질을 분리, 정제하였다. 활성물질 MT 1155는 UV, IR, 1H-NMR, 13C-NMR, mass,원소분석 등의 기기분석을 통하여 항진균성 항암물질인 toyocamycin으로 동정되었다. MT 1155는 ts/NRK 세포의 형태전환에 대한 활성외에도 PKA 효소활성 저해와 CTLL 세포에 대한 세포독성이 있으나 K562 소포형성 억제 및 PKC 효소활성에 대한 저해효과도 없었다.