• 한국작물학회지
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• 제49권3호
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• pp.237-242
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• 2004

우용유전자 도입을 통한 신품종 톨페스큐를 개발할 목적으로 Agrobacterium을 이용한 효율적인 형질전환 체계를 확립하였다 톨페스큐 성숙종자 유래의 캘러스를 standard binary vector인 pIG121Hm을 가지는 Agrobacterium EHA101을 이용하여 감염시킨 후 공동배양하여 형질전환시켰다. Agrobacterium을 이용한 형질전환에 있어서 중요한 인자로 작용하는 몇 가지 요인에 대한 톨페스큐 캘러스의 형질전환 효율을 GUS 유전자의 발현정도로 조사하였다. Agrobacterium 감염시에 접종배지와 공동배양배지에 $200\mu\textrm{M}$의 acetosyringone(AS)을 첨가해 주었을 때 형질전환 효율이 증가 되었으며, 공동배양기간을 5일까지 증가시켰을 때 형질전환효율이 증가되었다. 또한 Agrobacterium 감염시에 $200\mu\textrm{M}$의 AS와 0.l%의 Tween20을 동시에 첨가해 주었을 때 가장 높은 형질전환 효율을 나타내었다. 50 mg/L.의 hygromycin이 첨가된 선발배지에서 살아남은 캘러스로부터 정상적인 식물체가 재분화 되었으며 이들 형질전환체를 GUS 염색과 Southern blot 분석을 실시하여 본 결과 발현백터의 T-DNA 영역이 형질전환 식물체의 genome에 성공적으로 도입되었음을 확인할 수 있었다. 본 연구를 통하여 확립된 효율적인 형질전환 시스템은 분자육종을 통한 신품종 톨페스큐의 개발에 유용하게 이용될 수 있을 것이다.

• 한국초지조사료학회지
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• 제26권4호
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• pp.193-198
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• 2006

유용유전자 도입을 통한 신품종 오차드그래스를 개발할 목적으로 Agrobacterium을 이용한 효율적인 형질전환 체계를 확립하였다. 오차드그래스 성숙종자 유래의 캘러스를 standard binary vector인 pIG121Hm을 가지고 있는 Agrobacterium을 이용하여 감염시킨 후 공동배양하여 형질전환 시켰다. Agrobacterium을 이용한 형질전환에 있어서 중요한 인자로 작용하는 AS 첨가와 오차드그래스 품종에 따른 캘러스의 형질전환 효율의 차이를 GUS 유전자의 발현정도로 조사하였다. 'Roughricer' 품종의 형질전환 효율이 가장 우수하였으며, Agrobacterium 감염시에 접종배지와 공동배양배지에 $200{\mu}M$의 AS를 첨가해 주었을 때 형질전환 효율이 증가하는 것으로 나타났다. 50 mg/L의 hygromycin이 첨가된 선발배지에서 살아남은 캘러스로부터 정상적인 식물체가 재분화 되었으며 이들 형질 전환체에 대한 GUS 염색과 PCR 분석을 실시한 결과 발현벡터의 T-DNA 영역이 형질전환식물체의 genome에 성공적으로 도입되었음을 확인할 수 있었다. 본 연구를 통하여 확립된 효율적인 형질전환시스템은 환경스트레스 내성 신품종 오차드그래스의 개발에 유용하게 이용될 수 있을 것이다.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제30권1호
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• pp.41-51
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• 2008

Mucoepidermoid carcinoma (MEC) is the most common malignant salivary gland tumor which compromises about 6$\sim$8% of all tumors followed by the adenoid cystic carcinoma (ACC) and adenocarcinoma. Most deaths from salivary carcinomas are caused by recurrent or metastatic lesions that are resistant to conventional therapy. Therefore, knowledge of cellular properties and tumor-host interactions that influence the vascular metastasis is important for the design of more effective therapy of salivary carcinomas. Neoangiogenesis is essential for tumor growth, which is postulated to be fundamentally dependent on the induction of stromal neovascularization. However, how neovascularization takes place in live tissue has not been fully established, especially in recruitment and differentiation of endothelial cells in the salivary gland tumors. Vascular endothelial growth factor (VEGF) is a heparin-binding, dimeric polypeptide growth factor known to exert its mitogenic activity specifically on endothelial cells. VEGF has been shown th be directly involved in angiogenesis, which in essential for the pathogenesis of many solid tumors. von Willebrand factor (vWF) is a large multimeric protein synthesized by megakaryocytes and endothelial cells that enable platelets to adhere to exposed subendothelium and, as well, to respond to changes in the blood flow. Recent studies suggest that increased levels of vWF correlate with progression of disease, metastasis, or survival time and thus may have a prognostic significance. vWF is explained as an acute phase proteins which is increased in cancer or as a result of increased endothelial cell synthesis associated with tumor-induced angiogenesis. Due to adhesive properties of vWF, its increased concentrations may also contribute metastasis of tumor. In this study, we determined the mRNA expression of VEGF and vWF in salivary ACC, MEC and pleomorphic adenoma by in situ hybridization. As a result, stronger expression of VEGF and vWF was seen in salivary ACC and MEC which has more invasive nature than the salivary benign tumor.

• 원예과학기술지
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• 제31권3호
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• pp.328-336
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• 2013

본 연구는 외국 종자 회사의 토마토 $F_1$ 품종들을 대상으로 토마토황화잎말림바이러스(TYLCV) 저항성 분자마커 분석과 포장병리검정을 통해 각 품종의 저항성 유전자형과 내병성 수준을 분석하고, 원예형질 특성평가를 통해 TYLCV 저항성 품종보급과 분리육종에 적절한 품종선발을 위해 수행되었다. 40개 공시품종의 분자마커 및 병리검정 결과, 대부분 저항성으로 표기된 품종들이 TYLCV 저항성 유전자인 Ty-1, Ty-3, 또는 Ty-3a유전자를 이형접합 또는 동형접합으로 지니고 있으며, 표현형에서도 매우 낮은 발병률을 보였다. 반면, 중간 저항성으로 표기된 4 품종 중 3 품종은 18.1-33.3%의 발병률을 보였으며, 마커형이 이병성이었다. 내병성이 확인된 $F_1$품종들을 대상으로 원예형질 특성조사 결과, 유럽형 TYLCV 저항성 대과종 품종은 국내 선호 대비종보다 비교적 수량이 높고 당도 및 당산도도 크게 떨어지지 않아 국내용 품종 육성재료로 적합하였지만, 높은 과실경도의 문제점이 있었다. 반면, 소과종 품종들은 수량, 당도 등에서 국내 선호 품종보다 낮고 절간장도 길어 이들을 활용한 고품질 TYLCV 저항성 품종 육성을 위해서는 대과종에 비해 많은 시간과 노력이 소요될 것으로 판단되었다.

• 생명과학회지
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• 제27권8호
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• pp.958-964
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• 2017

Autophagy는 세포 내에서 세포의 재활용과 다양한 스트레스에 세포 homeostasis와 survival에 중요한 역할을 한다. 최근 연구에서는 autophagy 활성이 oncogenes과 tumor suppressor genes의 발현이 조절됨으로써 암이 발달되거나 억제됨이 보고되고 있다. Autophagy의 유도는 정상세포에서는 암 발생을 예방하는데 관여하며, 손상된 세포사멸 기능을 가진 암세포에서는 특정세포사멸기전을 유발하는데 중요한 역할을 한다. 또한 autophagy 억제는 항암약물과 치료법에 저항을 나타내는 암세포를 민감하게 만들어 치료효능을 증가시킨다고 증명되고 있다. 그러나 cancer 치료에서의 autophagy의 역할은 아직까지 완전히 이해되지 않았다. Oral squamous cell carcinoma(OSCC)는 구강암의 90% 이상을 차지하고 있으며, 전세계적으로 6th 가장 흔한 암중의 하나로, 최근 2배 이상 증가하고 있으며 높은 mortality rate를 보이고 있다. 구강암에서의 autophagy의 역할은 다른 암들과 마찬가지로 종양형성의 초기 단계 동안 종양억제성을 보이나, 종양진행 동안은 종양세포 생존에 관여하는 두 가지의 기능을 나타내는 것으로 보고되고 있다. 본 리뷰에서는, 암에서의 autophagy의 조절에 대한 다양한 역할을 요약하고, 이를 바탕으로 효과적인 암 치료를 위한 유망한 target으로 autophagy의 가능성을 제시하고자 한다.

• Journal of Microbiology and Biotechnology
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• 제10권6호
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• pp.789-796
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• 2000

In order to analyze the effects of tktA, $aroF^{FBR}$, and aroL expression in a tryptophan-producing Escherichia coli, a series of plasmids carrying the genes were constructed. Introduction of tktA, $aroF^{FBR}$, and aroL into the E. coli strain resulted in approximately 10-20 fold increase in the activities of transketolase, the feedback inhibition-resistant 3-deoxy-D-arabinoheptulsonate-7-phosphate synthase, and shikimate kinase. Expression of $aroF^{FBR}$ in the aroB mutant strain of E. coli resulted in the accumulation of 10 mM of 3-deoxy-D-arabinoheptulsonate-7-phosphate (DAHP) in the medium. Simultaneous expression of tktA and $aroF^{FBR}$ in the strain further increased the amount of excreted DAHP to 20 mM. In contrast, the mutant strain which has no gene introduced accumulated 0.5 mM of DAHP. However, the expression of tktA and $aroF^{FBR}$ in a tryptophan-producing E. coli strain did not lead to the increased production of tryptophan, but instead, a significant amount of shikimate, which is an intermediate in the tryptophan biosynthetic pathway, was excreted to the growth medium. Despite the fact that additional expression of shikimate kinase in the strain could possibly remove 90% of excreted shikimate to 0.1 mM, the amount of tryptophan produced was still unchanged. Removing shikimate using a cloned aroL gene caused the excretion of glutamate, which suggests disturbed central carbon metabolism. However, when cultivated in a complex medium, the strain expressing tktA, $aroF^{FBR}$, and aroL produced more tryptophan than the parental strain. These data indicate that additional rate-limiting steps are present in the tryptophan biosynthetic pathway, and the carbon flow to the terminal pathway is strictly regulated. Expressing tktA in E. coli cells appeared to impose a great metabolic burden to the cells as evidenced by retarded cell growth in the defined medium. Recombinant E. coli strains harboring plasmids which carry the tktA gene showed a tendency to segregate their plasmids almost completely within 24h.

• 한국식물생명공학회:학술대회논문집
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• 한국식물생명공학회 2002년도 추계학술대회
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• pp.69-75
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• 2002

Sterols play two major roles in plants: a bulk component in biological membranes and precursors of plant steroid hormones. Physiological effects of plant steroids, brassinosteroids (BRs), include cell elongation, cell division, stress tolerance, and senescence acceleration. Arabidopsis mutants that carry genetic defects in BR biosynthesis or its signaling display characteristic phenotypes, such as short robust inflorescences, dark-green round leaves, and sterility. Currently there are more than 100 dwarf mutants representing 7 genetic loci in Arabidopsis. Mutants of 6 loci, dwf1/dim1/cbb1, cpd/dwf3, dwf4, dwf5, det2/dwf6, dwf7 are rescued by exogenous application of BRs, whereas bri1/dwf2 shares phenotypes with the above 6 loci but are resistant to BRs. These suggest that the 6 loci are defective in BR biosynthesis, and the one locus is in BR signaling. Biochemical analyses, such as intermediate feeding tests, examining the levels of endogenous BR, and molecular cloning of the genes revealed that dwf7, dwf5, and dwf1 are defective in the three consecutive steps of sterol biosynthesis, from episterol to campesterol via 5-dehydroepisterol. Similarly, det2/dwf6, dwf4, and cpd/dwf3 were shown to be blocked in $D^4$ reduction, 22a-hydroxylation, and 23 a-hydroxylation, respectively. A signaling mutant bri1/dwf2 carries mutations in a Leucine-rich repeat receptor kinase. Interestingly, the bri1 mutant was shown to accumulate significant amount of BRs, suggesting that signaling and biosynthesis are dynamically coupled in Arabidopsis. Thus It is likely that transgenic plants over-expressing the rate-limiting step enzyme DWF4 as well as blocking its use by BRI1 could dramatically increase the biosynthetic yield of BRs. When applied industrially, BRs will boost new sector of plant biotechnology because of its potential use as a precursor of human steroid hormones, a novel lead compound for cholesterol-lowering effects, and a various application in plant protection.

• 미생물학회지
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• 제30권2호
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• pp.88-95
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• 1992

유전공학 기법으로 번형시킨 Km' plasmid 들의 전이를 30.deg.C 의 Luris-Bertani broth 에서 실시하였으며, 그 전이 빈도에 대한 donor 와 recipient 의 균주와 함께 pH 의 영향을 연구하였다. GEM 균주들과 NI 균주의 Km'plasmid 의 전이빈도는 recipient 가 MTI 일 경우 pH 7 에서 약 $10^{-5}$ 로 비슷하였으나 CS 균주인 DKC601 에서는 Km'plasmid 의 전이빈도가 $2.2 * 10^{-7}$ 로 훨씬 떨어졌다. 그리고 recipient 가 lab. strain (E. coli HB101) 인 경우에도 Km'plasmid 의 전이경향은 GEM 균주들과 NI 균주사이에 큰차이가 없었다. 또 어느 균주의 경우에나 pH 7 일 때의 전이 빈도가 $10^{-5}$ 정도로 가장 높게 나타났으며, pH 5 와 pH 9 에서는 그보다 조금 떨어졌다. 그러나 E. coli C600을 host 로 하여 제조한 CS 균주(DKC601)에서는 Km'plasmid 의 전이 빈도가 다른 GEM 균주들에 비하여 $10^{2}$ $-10^{3}$ 배 낮았으며 pH 4와 9 에서 6 시간의 conjugation 후에도 전이가 전혀 일어나지 않았다. Conjugant 에서의 plasmid의 재배열은 lab, strain 을 recipient 로 했을 경우에는 별로 없었지만, NI 균주를 recipient 로 했을 경우에 많이 나타났으며, 특히 donor 가 NI 균주보다 GEM 균주인 경우에 더욱 다양하였다. 그러나 pH 에 따른 타이는 그렇게 크지 않았다.

• Journal of Korean Neurosurgical Society
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• 제59권6호
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• pp.551-558
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• 2016

Malignant glioma cells invading surrounding normal brain are inoperable and resistant to radio- and chemotherapy, and eventually lead to tumor regrowth. Identification of genes related to motility is important for understanding the molecular biological behavior of invasive gliomas. According to our previous studies, Metallothionein 1E (MT1E) was identified to enhance migration of human malignant glioma cells. The purpose of this study was to confirm that MT1E could modulate glioma invasion in vivo. Firstly we established 2 cell lines; MTS23, overexpressed by MT1E complementary DNA construct and pV12 as control. The expression of matrix metalloproteinases (MMP)-2, -9 and a disintegrin and metalloproteinase 17 were increased in MTS23 compared with pV12. Furthermore it was confirmed that MT1E could modulate MMPs secretion and translocation of NFkB p50 and B-cell lymphoma-3 through small interfering ribonucleic acid knocked U87MG cells. Then MTS23 and pV12 were injected into intracranial region of 5 week old male nude mouse. After 4 weeks, for brain tissues of these two groups, histological analysis, and immunohistochemical stain of MMP-2, 9 and Nestin were performed. As results, the group injected with MTS23 showed irregular margin and tumor cells infiltrating the surrounding normal brain, while that of pV12 (control) had round and clear margin. And regrowth of tumor cells in MTS23 group was observed in another site apart from tumor cell inoculation. MT1E could enhance tumor proliferation and invasion of malignant glioma through regulation of activation and expression of MMPs.

• Nutrition Research and Practice
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• 제11권3호
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• pp.190-197
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• 2017

BACKGROUND/OBJECTIVES: Gallus gallus domesticus (GD) is a natural mutant breed of chicken in Korea with an atypical characterization of melanin in its tissue. This study investigated the effects of melanin extracts of GD on osteoblast differentiation and inhibition of osteoclast formation. MATERIALS/METHODS: The effects of the melanin extract of GD on human osteoblast MG-63 cell differentiation were examined by evaluating cell viability, osteoblast differentiation, and expression of osteoblast-specific transcription factors such as bone morphogenetic protein 2 (BMP-2), small mothers against decapentaplegic homologs 5 (SMAD5), runt-related transcription factor 2 (RUNX2), osteocalcin and type 1 collagen (COL-1) by reverse transcription-polymerase chain reaction and western blotting analysis. We investigated the inhibitory effect of melanin on the osteoclasts formation through tartrate-resistant acid phosphatase (TRAP) activity and TRAP stains in Raw 264.7 cell. RESULTS: The melanin extract of GD was not cytotoxic to MG-63 cells at concentrations of $50-250{\mu}g/mL$. Alkaline phosphatase (ALP) activity and bone mineralization of melanin extract-treated cells increased in a dose-dependent manner from 50 to $250{\mu}g/mL$ and were 149% and 129% at $250{\mu}g/mL$ concentration, respectively (P < 0.05). The levels of BMP-2, osteocalcin, and COL-1 gene expression were significantly upregulated by 1.72-, 4.44-, and 2.12-fold in melanin-treated cells than in the control cells (P < 0.05). The levels of RUNX2 and SMAD5 proteins were higher in melanin-treated cells than in control vehicle-treated cells. The melanin extract attenuated the formation of receptor activator of nuclear factor kappa-B ligand-induced TRAP-positive multinucleated RAW 264.7 cells by 22%, and was 77% cytotoxic to RAW 264.7 macrophages at a concentration of $500{\mu}g/mL$. CONCLUSIONS: This study provides evidence that the melanin extract promoted osteoblast differentiation by activating BMP/SMADs/RUNX2 signaling and regulating transcription of osteogenic genes such as ALP, type I collagen, and osteocalcin. These results suggest that the effective osteoblastic differentiation induced by melanin extract from GD makes it potentially useful in maintaining bone health.