• Tuberculosis and Respiratory Diseases
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• 제47권5호
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• pp.618-628
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• 1999

연구배경: 세포성장은 세포증식과 세포죽음의 균형에 의해 이루어 진다. 세포성장에 관여하는 여러 growth factor증 IGF-I은 IGF-IR와 결합하여 세포증식을 유발하는 mitogen으로 알려져 있다. 또한 IGF-I에 결합하는 IGFBPs중에 IGFBP-3는 혈액내에 가장 많은 carrier protein으로, IGF-I과 결합하여 IGF-I의 세포증식 효과를 증가 혹은 억제시킨다. 방 법: 3T3 fibroblast 세포를 이용하여 IGF-I과 IGF-IR transcripts를 northern blot으로 확인하고, IGF-I에 의한 mitogenic effect를 MTT assay 및 $^3H$-thymidine incorporation test로 관찰하고, IGF-I의 receptor인 IGF-IR의 활성화를 보기 위해 intracellular $\beta$-subunit의 tyrosine kinase domain의 phosphorylation을 western blot으로 관찰하였다. 또한 IGFBP-3가 3T3 세포에서 mitogenic effect에 미치는 영향을 보기 위해 anti-IGFBP-3와 ${\alpha}IR_3$을 단독 및 병용투여하여 관찰하였다. 결 과: 3T3 세포는 IGF-I와 IGF-IR의 mRNA expression을 보였으며, IGF-I을 투여시 IGF-IR의 intracelluar cytoplasmic protein인 $\beta$-subunit의 tyrosine kinase domain을 phosphorylation시켜 활성화시키며, 5%, 1% serum-containing media에서 세포증식을 보였으나, serum-free media에서는 세포증식을 보이지 않았다. 또한 anti-IGFBP-3 투여와 ${\alpha}IR_3$과 anti-IGFBP-3를 병용투여시는 세포종식이 각각 2배이상 증가하였으나, ${\alpha}IR_3$을 4시간 전처치후 ${\alpha}IR_3$과 anti-IGFBP-3를 병용투여시는 anti-IGFBP-3에 의한 세포종식이 보이지 않은 것으로 보아 IGF -I/IGFBP-3 결합에서 분리되는 free IGF-I어l 의해 세포증식이 유도된 것으로 생각된다. 결 론: IGF-I은 IGF-IR를 phosphorylation시켜 mitogenic effect를 보이며, IGFBP-3는 IGF-I의 mitogenic effect를 억제하는 것으로 생각된다.

• Nuclear Medicine and Molecular Imaging
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• 제40권4호
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• pp.218-227
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• 2006

목적 : 헤르페스 심플렉스 1형 바이러스 티미딘 키나제(Herpes simplex virus type 1 thymidine kinase. HSV1-tk) 유전자는 보고 유전자로서 필요한 조건뿐만 아니라 별도의 치료 유전자를 따로 이입할 필요가 없다는 장점을 가지고 있어 유전자 영상과 치료에서 가장 널리 사용되는 유전자이다. 본 연구에서는 간암세포주에서 HSV1-tk 보고 유전자 발현을 비침습적 PET 영상으로 평가하는데 있어서 $9-(4-[^{18}F]Fluoro-3-hydroxymethylbutyl)$guanine ($[^{18}F]FHBG$)의 유용성을 평가하고자 하였다. 대상 및 방법 : $[^{18}F]FHBG$는 triester로부터 8단계를 거쳐 합성하였다. $[^{18}F]FHBG$는 전구체로 N2-monomethoxytrityl-9-[4-(tosyl)-3-monomethoxytritylmethylbutyl]guanine를 사용하고 kyptofix [2.2.2.]를 이용한 친핵성 반응으로 $120^{\circ}C$에서 20분 동안 반응한 후에 1 N HCl로 보호기를 제거함으로써 합성하였다. HSV1-tk 보고 유전자가 이입되어 있는 세포주인 MCA-tk와 이입되지 않은 MCA 세포주를 이용하여 in vitro 상에서의 $[^{18}F]FHBG$의 섭취 및 방출 실험을 실시하였으며 섭취량과 발현량의 상관성 평가를 위해 세포수 백분율에 따른 섭취실험을 실시하였다. In vivo 상에서의 평가를 위하여 피하 종양 형성 동물모델을 이용하여 microPET생체영상을 획득하였다. 결과: 합성된 $[^{18}F]FHBG$를 역상 HPLC를 사용하여, 머무름 시간 16-18분에서 분리하였다. 반감기를 고려한 방사화학적 수율은 20-25%, 방사화학적 순도는 95% 이상이었으며 비방사능은 55.0 $GBq/{\mu}\;mol$ 이상이었다. HSV1-tk 유전자가 이입된 MCA-tk 세포에서는 특이적인 $[^{18}F]FHBG$의 집적이 발생하였으며 대조군인 MCA에서는 거의 집적이 이루어지지 않았다. 또한, 방출 실험에서 방출 후 1시간 경과까지 86% 이상의 $[^{18}F]FHBG$가 세포내에 잔류하였다. MCA-tk 세포주의 비율이 증가함에 따라 $[^{18}F]FHBG$의 섭취량도 직선적 상관관계($R^2=0.995$)에 따라 증가하여 기질의 섭취량이 유전자 발현량을 잘 반영하고 있음이 확인되었다. MicroPET을 이용한 생체영상에서도 MCA와 MCA-tk 에서 확연한 집적의 차이를 보여주었다. 결론: 간암세포주에서 HSV1-tk 유전자의 발현 정도와 지속성 그리고 위치를 확인하기 위한 비침습적 PET 영상을 위한 기질로서 $[^{18}F]FHBG$는 매우 유용할 것으로 기대된다.

• Biomolecules & Therapeutics
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• 제19권2호
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• pp.187-194
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• 2011

Atherosclerosis and post-angiography restenosis are associated with intimal thickening and concomitant vascular smooth muscle cell (VSMC) proliferation. Obovatol, a major biphenolic component isolated from the Magnolia obovata leaf, is known to have anti-inflammatory and anti-tumor activities. The goal of the present study was to enhance the inhibitory effects of obovatol to improve its potential as a preventive or therapeutic agent in atherosclerosis and restenosis. Platelet-derived growth factor (PDGF)-BB-induced proliferation of rat aortic smooth muscle cells (RASMCs) was examined in the presence or absence of a newly synthesized obovatol derivative, OD78. The observed anti-proliferative effect of OD78 was further investigated by cell counting and [$^3H$]-thymidine incorporation assays. Treatment with 1-4 ${\mu}M$ OD78 dose-dependently inhibited the proliferation and DNA synthesis of 25 ng/ml PDGF-BB-stimulated RASMCs. Accordingly, OD78 blocked PDGF-BB-induced progression from the $G_0/G_1$ to S phase of the cell cycle in synchronized cells. OD78 decreased the expression levels of CDK4, cyclin E, and cyclin D1 proteins, as well as the phosphorylation of retinoblastoma protein and proliferating cell nuclear antigen; however, it did not change the CDK2 expression level. In addition, OD78 inhibited downregulation of the cyclin-dependent kinase inhibitor (CKI) $p27^{kip1}$. However, OD78 did not affect the CKI $p21^{cip1}$ or phosphorylation of early PDGF signaling pathway. These results suggest that OD78 may inhibit PDGF-BB-induced RASMC proliferation by perturbing cell cycle progression, potentially through $p27^{kip1}$ pathway activation. Consequently, OD78 may be developed as a potential anti-proliferative agent for the treatment of atherosclerosis and angioplasty restenosis.

• Bulletin of the Korean Chemical Society
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• 제28권12호
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• pp.2449-2453
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• 2007

L-[18F]FMAU ([18F]1b) was prepared from the precursor 2-O-[(trifluoromethyl)-sulfonyl]-1,3,5-tri-Obenzoyl- α-L-ribofuranose, by coupling the radioactive fluoro-sugar with the corresponding silylated thymine in 4 steps. The final products, including the α and β anomers, were purified using reverse phase HPLC with an appropriate solvent (5% CH3CN/H2O) at a flow rate of 3.0 mL/min. The total elapsed time of synthesis was about 180-200 min from EOB. The α/β anomeric ratio of the compounds was about 1:9, and the radiochemical purity of the product (β-form) was >98% with decay-corrected yields of 25-35%. All radioactive samples were confirmed using co-injection with pure non-radioactive analogues in every step. In the cellular uptake in vitro test of herpes simplex virus-thymidine kinase (HSV1-TK) gene expressed cells, the percent uptake of injected dose (%ID) of L- and D-FMAU was 37.28 and 65.86, respectively after 240 min incubation. However, the relative uptake (MCA-TK/MCA cellular uptake ratio) of L-FMAU was higher than that of D-FMAU (%ID of L-FMAU, 0.36 and D-FMAU, 0.93 after 240 min incubation in MCA cells). This means that L-FMAU will show better specific HSV1-TK gene expressed cell uptake for selective HSV1-TK gene imaging.

• Journal of Microbiology and Biotechnology
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• 제10권1호
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• pp.27-34
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• 2000

The chloroform and methanol (2;1, v/v) extract from an edible plant, Actinidia arguta Planchon, appeared to possess antitumor activity against human leukemias Jurkat T and U937 cells through inducing apoptosis. The substance in the solvent extract was purified by silica gel column chromatography, preparative TLC, and Sephadex LH-20 column chromatography. Characteristics of the substance analyzed by UV scanning analysis, $^1H$ and $^{13}C$ NMR spectra suggested that the substance belongs to the chlorophyll derivatives-like group. The $IC_{50}$ value of the chlorophyll derivative (Cp-D) determined by MTT assay was $15\mu\textrm{g}/ml$ for Jurkat, $10\mu\textrm{g}/ml$ for U937, and $11.4\mu\textrm{g}/ml$ for HL-60m and was more toxic to these leukemias than to solid tumors or normal fibroblast. In order to elucidate cellular mechanisms underlying the cytotoxicity, the effect of the Cp-D on Jurkat T cells was investigated. When cells were treated with the Cp-D at a concentration of $15\mu\textrm{g}/ml$, [3H]thymidine incorporation declined rapidly and wa undetectable in 1h. However, no significant changes were made in the cell cycle distribution of the cells by 24h. The sub-Gl peak representing apoptotic cells began to be detectable in 36h, at which time apoptotic DNA fragmentation was also detected on agarose gel electrophoresis, demonstrating that the cytotoxic effect of the Cp-D is attributable to the induced apoptosis. Under the same conditions, although the protein level of cyclin-dependent kinases such as cdc4, csk6, cdk2, and cdc2 was not significantly changed until 24h, the kinase activity of all c안 rapidly declined and reached a minimum level within 1-6h and then recovered to the initial level by 12h and sustained until 24h. These results suggest that inactivation of cdks at an inappropriate time during the cell cycle progression in jurkat T cells following a treatment with the Cp-D leads to induction of apoptotic cell death.

• The Korean Journal of Physiology and Pharmacology
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• 제17권3호
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• pp.203-208
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• 2013

As the abnormal proliferation of vascular smooth muscle cells (VSMCs) plays a critical role in the development of atherosclerosis and vascular restenosis, a candidate drug with antiproliferative properties is needed. We investigated the antiproliferative action and underlying mechanism of a newly synthesized naphthoquinone derivative, 5,8-dimethoxy-2-nonylamino-naphthalene-1,4-dione (2-nonylamino-DMNQ), using VSMCs treated with platelet-derived growth factor (PDGF). 2-Nonylamino-DMNQ inhibited proliferation and cell number of VSMCs induced by PDGF, but not epidermal growth factor (EGF), in a concentration-dependent manner without any cytotoxicity. This derivative suppressed PDGF-induced $[^3H]$-thymidine incorporation, cell cycle progression from $G_0/G_1$ to S phase, and the phosphorylation of phosphor-retinoblastoma protein (pRb) as well as the expression of cyclin E/D, cyclin-dependent kinase (CDK) 2/4, and proliferating cell nuclear antigen (PCNA). Importantly, 2-nonylamino-DMNQ inhibited the phosphorylation of PDGF receptor${\beta}$(PDGF-$R{\beta}$) enhanced by PDGF at $Tyr^{579}$, $Tyr^{716}$, $Tyr^{751}$, and $Tyr^{1021}$ residues. Subsequently, 2-nonylamino-DMNQ inhibited PDGF-induced phosphorylation of STAT3, ERK1/2, Akt, and $PLC{\gamma}1$. Therefore, our results indicate that 2-nonylamino-DMNQ inhibits PDGF-induced VSMC proliferation by blocking PDGF-$R{\beta}$ autophosphorylation, and subsequently PDGF-$R{\beta}$-mediated downstream signaling pathways.

• Archives of Pharmacal Research
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• 제25권5호
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• pp.685-690
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• 2002

The mitogen-stimulated serine/threonine kinase $p70^{S6k}$ plays an important role in the progression of cells from $G_0/G$_1$$ to S phase of the cell cycle by translational up-regulation of a family of mRNA transcripts family of mRNA transcripts which contain polypyrimidine tract at their 5 transcriptional start site. Here, we report that $p70^{S6k}$ was constitutively phosphorylated and activated to various degrees in serum-deprived AGS, A2058, HT-1376, MG63, MCF7, MDA-MB-435S, MDA-MB-231 and MB-157. Rapamycin treatment induced a significant dephosphorylation and inactivation of $p70^{S6k}$ in all cancer cell lines, while wortmannin, a specific inhibitor of PI3-K, caused a mild dephosphorylation of $p70^{S6k}$ in AGS, MDA-MB-435S and MB-157. In addition, SQ20006, methylxanthine phosphodiesterase inhibitor, reduced the phosphorylation of $p70^{S6k}$ in all cancer cells tested. Consistent with inhibitory effect of rapamycin on $p70^{S6k}$ activity, rapamycin inhibited [$^3H$]-thymidine incorporation and increased the number of cells at $G_{0}G_{1}$ phase. Furthermore, these inhibitory effects were accompanied by the decrease in growth of cancer cells. Taken together, the results indicate that the antiproliferative activity of rapamycin might be attributed to cell cycle arrest at $G_{0}G_{1}$ phase in human cancer cells through the inhibition of constitutively activated $p70^{S6k}$ of cancer cells and suggest $p70^{S6k}$ as a potential target for therapeutic strategies aimed at preventing or inhibiting tumor growth.

• Molecular & Cellular Toxicology
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• 제1권3호
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• pp.172-178
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• 2005

[ $21{\alpha}$ ]- and ${\beta}$-Methylmelianodiol were isolated as the inhibitor of IL-5 bioactivity from Poncirus tripoliata. To develope as an anti-septic drug, the genotoxicity of $21{\alpha}\;-and\;{\beta}-methylmelianodiol$ was subjected to high throughput toxicity screening (HTTS) because they revealed strong IL-5 inhibitory activity and limitation of quantity. Mouse lymphoma thymidine kinase ($tk^{+/-}$) gene assay (MOLY), single cell gel electrophoresis (Comet) assay in mammalian cells and Ames reverse mutation assay in bacterial system were used as simplified, inexpensive, short-term in vitro screening tests in our laboratory. These compounds are not mutagenic in S. typhimurium TA98 and TA100 strains both in the presence and absence of metabolic activation. Before performing the comet assay, $IC_{20}$ of $21{\alpha}-methylmelianodiol$ was determined the concentration of $25.51\;{\mu}g/mL\;and\;21.99\;{\mu}g/mL$ with and without S-9, respectively. Also $21{\beta}-methylmelianodiol$ was determined the concentration of $24.15\;{\mu}g/mL\;and\;\;22.46\;{\mu}g/mL$ with and without S-9, respectively. In the comet assay, DNA damage was not observed both $21{\alpha}-methylmelianodiol\;and\;21{\beta}-methylmelianodiol$ in mouse lymphoma cell line. Also, the mutant frequencies in the treated cultures were similar to the vehicle controls, and none of $21{\alpha}\;-and\;{\beta}-methylmelianodiol$ with and without S-9 doses induced a mutant frequency over. twice the background. It is suggests that $21{\alpha}\;-and\;{\beta}-methylmelianodiol$ are non-mutagenic in MOLY assay. The results of this battery of assays indicate that $21{\alpha}\;-and\;{\beta}-methylmelianodiol$ have no genotoxic potential in bacterial or mammalian cell systems. Therefore, we suggest that $21{\alpha}\;-and\;{\beta}-methylmelianodiol$, as the optimal candidates with both no genotoxic potential and IL-5 inhibitory effects must be chosen.

• Clinical and Experimental Pediatrics
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• 제45권3호
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• pp.354-361
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• 2002

목 적: 본 연구에서는 in vitro 및 in vivo에서 HSV-TK 유전자 치료의 bystander 효과 및 기전을 관찰하고, 싸이토카인 유전자의 병합 치료가 bystander 효과를 증폭시킬 수 있는지 조사하여 그 결과를 향후 신경모세포종 치료에 적용하고자 본 연구를 시행하였다. 방 법: A/J 마우스 신경모세포종 모델에서, neuro-2a/TK 세포와 unmodified neuro-2a세포를 여러 비율로 혼합하여 접종한 후 GCV를 투여하여 종양의 크기 변화 및 생존 유무를 관찰하였다. 마우스 신경모 세포종에서 bystander 효과의 기전을 알아보기 위해 neuro-2a/TK 세포를 주입한 마우스의 조직을 절개하여 connexin 43, CD4+ 및 CD8+ 세포 침윤을 관찰 하였다. 10% 및 25% HSV-TK 투여 군에서 neuro-2a/IL-2 세포의 투여가 bystander 효과를 증폭시키는 지 조사하였다. 결 과 : 1) in vitro 및 in vivo에서 bystander 효과는 뚜렷하게 관찰되었다. 2) 마우스 신경모세포종의 면역 조직 화학 염색 검사에서 connexin 43 발현은 관찰되지 않았으나 많은 수의 CD4+ 및 CD8+ T 세포의 침윤이 관찰되었다. 3) 10% 및 25% HSV-TK 투여군의 마우스에서 neuro-2a/IL-2 세포의 투여는 대조군과 비교하여 종양의 성장을 더 억제 시켰다. 결 론: In vitro 및 in vivo에서 HSV-TK/GCV 유전자 치료의 bystander 효과는 뚜렷하였으며, 그 기전으로 면역 세포가 중요한 역할을 할 것으로 추측된다. 그리고 bystander 효과는 IL-2 투여에 의해 증폭됨을 확인하였다. 이는 향후 신경모세포종의 수술 후 잔존암 치료에 HSV-TK/GCV 유전자 치료가 이용 가능할 것으로 생각된다.

• 핵의학기술
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• 제15권2호
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• pp.72-75
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• 2011

단순 헤르페즈 제1형 티미딘 키나제(Herpes simplex virus type 1 thymidine kinase. HSV1-tk) 유전자는 보고 유전자(reporter gene)로서 필요한 조건뿐만 아니라 별도의 치료 유전자를 따로 이입할 필요가 없다는 장점을 가지고 있어 유전자 영상과 치료에서 가장 널리 사용되는 유전자 중 하나이다. 본 연구는 HSV1-tk 보고 유전자의 기질로서 많이 사용하고 있는 9-(4-[$^{18}F$] Fluoro-3-hydroxymethylbutyl) guanine ([$^{18}F$] FHBG) 합성의 자동화와 더불어 최적의 합성 조건을 구현하기 위하여 실행하게 되었다. [$^{18}F$] FHBG 합성의 자동화를 위해 Explora-RN (CTI, USA) module을 사용하였다. 최적의 합성수율 조건을 찾기 위하여 반응시간의 변화(3 min, 5 min, 10 min)와 반응온도의 변화($110^{\circ}C$, $120^{\circ}C$, $130^{\circ}C$)를 주었다. 또한 precursor 용량의 변화(5 mg, 7 mg, 10 mg)에도 합성수율이 어떻게 영향을 미치는지 알아보았다. [$^{18}F$] fluorination 단계에서 가장 높은 합성수율을 보인 반응온도는 $130^{\circ}C$였고, 반응시간은 5분이었다. 반면 precursor의 용량 변화 실험에서는 10 mg을 넣었을 때의 합성 수율($32{\pm}1.2%$)에 비하여 5 mg과 7 mg의 양에서는 안정된 값을 얻지 못하였다. [$^{18}F$] FHBG 합성의 Explora-RN 모듈에서의 자동화를 완성하였고 최적의 합성수율을 재현할 수 있는 반응시간과 반응온도, precursor의 농도를 찾았다. 하지만 감량 precursor 방법은 낮은 농도에서 비교적 큰 편차를 보여 안정된 값을 얻지는 못하였다. 이에 따라 임상에 직접 적용하기 위해서 더 많은 연구가 시행되어져야 할 것이다.