• 미생물학회지
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• 제28권1호
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• pp.19-26
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• 1990

To examine the effects of sequence variations near the transcriptional start site on the rate of formation of the open complexes at bacteriophage $\lambda P_{R}$ promoter, two mutant promoters were created by site-specific mutagenesis using synthetic oligonucleotides. Mutant I coatains changes at positions -3 and -4 from TT to CC, thus having a 6-bp long G/C stretch between -10 region and transciptional start site (+1). Mutant II has changes at positions -5 and -6 from GG to AA, thereby having a 9-bp long A/T stretch between positions -11 and -3. Selective filter binding assays were performed to measure the rate of formation of the open complexes between the wild-type or two mutant $P_{R}$ promoters on 664 bp fragments and E. coli RNA polymerase at two temperatures. At 37.deg.C, the wild-type and two mutants showed similar rates for the formation of open complex. The second order rate constant $k_{a}$ and $\tau _{int}$, as determined from the .tau.-plot analysis, were $(6.0\pm0.4)\times10^{6}M^{-1}sec^{-1}$ and $11\pm5$sec, respectively. At 18.deg.C, however, the wild-type and two mutant promoters showed differences in the kinetic parameters. k for the wild-type promoter was (2.2$\pm$0.1)\times 10^{6}M^{-1}sec^{-1}$ and $\tau _{int}$ was 76$\pm$sec. Mutant I and II exhibited differences mainly in the rate of isomerization ($\tau_{int,I}=91\pm$10 sec, int,II=34$\pm$ sec), whereas the second order rate constant $k_{a}$ was similar to the wild type value. This result implies that at $18^{\circ}C$, the isomerization rate is determined by both protein conformational change and DNA melting, which are separable kinetically according to the 3-step mechanism of Roe et al.(1984,1985), and that the base changes affected mainly the rate of DNA melting as predicted.lting as predicted.

• Molecules and Cells
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• 제43권10호
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• pp.856-869
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• 2020

To elucidate the mechanism of action of HOXA11-AS in modulating the cisplatin resistance of nasopharyngeal carcinoma (NPC) cells. HOXA11-AS and miR-454-3p expression in NPC tissue and cisplatin-resistant NPC cells were measured via quantitative reverse transcriptase polymerase chain reaction. NPC parental cells (C666-1 and HNE1) and cisplatin-resistant cells (C666-1/DDP and HNE1/DDP) were transfected and divided into different groups, after which the MTT method was used to determine the inhibitory concentration 50 (IC₅₀) of cells treated with different concentrations of cisplatin. Additionally, a clone formation assay, flow cytometry and Western blotting were used to detect DDP-induced changes. Thereafter, xenograft mouse models were constructed to verify the in vitro results. Obviously elevated HOXA11-AS and reduced miR-454-3p were found in NPC tissue and cisplatin-resistant NPC cells. Compared to the control cells, cells in the si-HOXA11-AS group showed sharp decreases in cell viability and IC₅₀, and these results were reversed in the miR-454-3p inhibitor group. Furthermore, HOXA11-AS targeted miR-454-3p, which further targeted c-Met. In comparison with cells in the control group, HNE1/DDP and C666-1/DDP cells in the si-HOXA11-AS group demonstrated fewer colonies, with an increase in the apoptotic rate, while the expression levels of c-Met, p-Akt/Akt and p-mTOR/mTOR decreased. Moreover, the si-HOXA11-AS-induced enhancement in sensitivity to cisplatin was abolished by miR-454-3p inhibitor transfection. The in vivo experiment showed that DDP in combination with si-HOXA11-AS treatment could inhibit the growth of xenograft tumors. Silencing HOXA11-AS can inhibit the c-Met/AKT/mTOR pathway by specifically upregulating miR-454-3p, thus promoting cell apoptosis and enhancing the sensitivity of cisplatin-resistant NPC cells to cisplatin.

• 식물병연구
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• 제11권2호
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• pp.213-216
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• 2005

토마토 반점위조 바이러스(Tomato spotted wilt virus; TSWV)가 2004년 경기도 안양지역에서 토마토, 고추 등을 포함한 14개 채소 작물에서 발생하였다. TSWV검정은 지표식물 검정, IC/RT-PCR, VC/RT-PCR 및 Total RNA를 이용한 RT-PCR방법을 이용하였으며, TSWV가 발생한 작물의 종류는 토마토, 방울 토마토, 고추, 시금치, 치커리, 적치커리, 적겨자, 용설채, 트레비소, 감자, 들깨, 참깨, 호박, 쌈추 이었다. 포장에서의 발생율은 토마토, 고추 등 주요 작물에서 $30\%$에서 $100\%$ 발생하였으며,병징은 대부분 전형적인 원형반점이었으며, 괴저, 위조 및 심한 모자이크 병징으로 진전되었다. TSWV가 발생한 포장에서 채집한 꽃노랑 총채벌레(Frankliniella occidentalis)를 IC/RT-PCR 검정한 결과 감염율이 $90\%$이었다.

• Journal of Preventive Medicine and Public Health
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• 제38권3호
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• pp.330-336
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• 2005

Objectives : The aim of this study was to investigate the effects of bisphenol A (BPA), an estrogen-like environmental endocrine disrupter, on the placental function and reproduction in rats. The mRNA levels of the placental prolactin-growth hormone(PRL-GH) gene family, placental trophoblast cell frequency and reproductive data were analyzed. Methods : The pregnancies of F344 Fisher rats ($160g{\pm}20g$) were detected by the presence of the copulatory plug or sperm in the vaginal smear, which marked Day 0 of pregnancy. Pregnant rats were divided into three groups. The control group was intraperitoneally injected with a sesame oil vehicle. The two remaining groups were injected with 50 or 500 mg/kg B.W/day of BPA, resuspended in sesame oil, on either days 7 to 11 or 16 to 20 of pregnancy, with the rats sacrificed on either day 11 or 20, respectively. The mRNA levels of PRL-GH and Pit-1a and b isotype genes were analyzed by Northern blot hybridization and reverse transcription-polymerase chain reaction. The hormone concentrations were analyzed by radioimmunoassay, and the frequency of the placental trophoblast cells observed by a histochemical study. Reproductive data, such as the placental weight and litter size, were surveyed on day 20. The fetal weight was surveyed for 4 weeks after birth. A statistical analysis was carried out using the SAS program (version 8.1). Results : The mRNA levels of the PRL-GH gene family, such as placental lactogen I, Iv and II, prolactin like protein A, C and Cv, and decidual prolactin-related protein were significantly reduced due to BPA exposure. The mRNA levels of the Pit-1a and b isotype genes, which induce the expression of the PRL-GH gene family in the rat placenta, were also reduced due to BPA exposure. The PL-Iv and PL-II concentrations were reduced in the BPA exposed group. During the middle to last stage of pregnancy (Days 11-20), a high dose of BPA exposure reduced the frequency of spongiotrophoblast cells, which are responsible for the secretion of the PRL-GH hormones. Reproductive data, such as the placental and fetal weights and the litter size, were reduced, but that of the pregnancy period was extended in the BPA exposed compared to the control group. Conclusions : BPA disrupts the placental functions in rats, which leads to reproductive disorders.

• 한국식품영양과학회지
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• 제44권5호
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• pp.673-680
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• 2015

본 연구에서는 우렁쉥이 껍질 유래 다당류의 기능성식품 소재로의 활용 가능성을 확인하기 위하여 조다당류의 분리 및 정제를 통해 획분을 얻었으며 다양한 면역증강 효과를 확인하였다. 건조된 조다당류를 DEAE-sepharose CL-6B를 이용하여 크로마토그래피한 후 총당 및 uronic acid 함량을 분석한 결과, 증류수로 용출되는 비흡착 획분(APF-I, fraction No. 11~17)과 흡착된 후 NaCl 용액에 의해 용출되는 획분(APF-II, fraction No. 22~37)을 얻었다. 정제된 APF-I 및 APF-II의 이화학적 특성으로 총당 함량은 각각 66.62%, 27.03%, uronic acid 함량은 47.53%, 15.87%, hexosamine 함량은 16.62%, 46.79% 및 단백질 함량은 2.43%, 4.94%로 나타났다. APF-I 및 APF-II에 대해 RAW 264.7 세포에 처리하여 독성을 평가한 결과 $5{\mu}g/mL$ 농도까지 유의적으로 세포사멸이 나타나지 않아 세포독성이 없음을 확인할 수 있었다. Nitric oxide 생산량은 APF-I이 $5{\mu}g/mL$ 농도에서 $22.23{\mu}m$ 함량을 나타내어 LPS 대비 73.48%로 타 구간에 비해 높은 생성량을 나타내었으며, cytokine 생성량(TNF-${\alpha}$ 및 IL-6) 또한 APF-I $5{\mu}g/mL$ 농도에서 각각 LPS 대비 104%, 100.1%를 나타내어 LPS와 유사한 생성량을 나타내었다. Polymerase chain reaction을 통한 면역관련 유전자 발현 분석 결과, iNOS, COX-2, TNF-${\alpha}$, IL-6에서 APF-I 구간에서 LPS 처리군 보다 높은 발현량을 나타내어 면역증강을 목적으로 한 기능성식품 개발에 활용 가능하다고 사료된다.

• 한국동물학회지
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• 제27권2호
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• pp.103-116
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• 1984

유전자 구조 및 유전정보 흐름의 차이로 인하여 고등생물의 유전자를 미생물에 직접 cloning하면 원하는 유전자 산물을 얻지 못하는 경우가 많다. 이것을 극복하기 위해서는 화학적인 방법으로 유전자를 합성하든지, 또는 역제효소를 사용하여 고등생물의 mRNA로부터 유전자를 합성하여 cloning하는 방법을 사용한다. 본 연구에서는 oligo(dT)-cellulose column 방법으로 순수분리한 plasmid pBR322의 Pst I site에 cloning하였다. 우선 AMV reverse transcriptase로 primary cDNA를 합성하고, 알칼리를 처리하여 주형 RNA를 제거했다. 이번에는 이 primary cDNA를 주형으로 Klenow enzyme과 reverse transcriptase를 차례로 처리하여 double stranded DNA를 합성하고, 이 때 5' end 근처에 형성되는 hairpin loop을 Sl nuclease로 제거했다. Terminal deoxynucleotidyl transferase를 사용하여, 합성된 dsDNA에는 poly(dC) track을, Pst I endonuclease를 처리한 plasmid DNA에서는 poly(dG) track을 각각 붙인다음 이들을 서로 annealing시키고 E. coli에 transformation시켜서 크기가 큰 plasmid를 갖는 clone을 cracking 방법으로 일처 선별하였다. 이렇게 선별된 clone을 in 냐셔 hybridization 방법으로 조사하여 globin DNA가 들어간 colony를 이차 선별하고 여러 restriction enzyme으로 잘라보아 globin DNA가 cloning된 것을 확인하였다. 토끼 hemoglobin으로 immunize한 rat (Wistar)에서 뽑은 제일차 혈청과 염소에서 뽑은 제이차 혈청의 antibody를 사용한 radioimmunoassay방법으로, cloning된 globin gene이 대장균내에서 발현되는 지의 여부를 살펴 보았는데, 박테리아의 $\\beta$-lactamase와 토끼의 globin이 결합된 chimeric protein이 대장균 내에서 다량 합성되며, 이 단백질은 토끼 hemoglobin의 antigenic determinant를 가지고 있음을 알 수 있었다.

• Genomics & Informatics
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• 제11권4호
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• pp.245-253
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• 2013

A radioresistant cell line was established by fractionated ionizing radiation (IR) and assessed by a clonogenic assay, flow cytometry, and Western blot analysis, as well as zymography and a wound healing assay. Microarray was performed to profile global expression and to search for differentially expressed genes (DEGs) in response to IR. H460R cells demonstrated increased cell scattering and acidic vesicular organelles compared with parental cells. Concomitantly, H460R cells showed characteristics of increased migration and matrix metalloproteinase activity. In addition, H460R cells were resistant to IR, exhibiting reduced expression levels of ionizing responsive proteins (p-p53 and ${\gamma}$-H2AX); apoptosis-related molecules, such as cleaved poly(ADP ribose) polymerase; and endoplasmic reticulum stress-related molecules, such as glucose-regulated protein (GRP78) and C/EBP-homologous protein compared with parental cells, whereas the expression of anti-apoptotic X-linked inhibitor of apoptosis protein was increased. Among DEGs, syntrophin beta 2 (SNTB2) significantly increased in H460R cells in response to IR. Knockdown of SNTB2 by siRNA was more sensitive than the control after IR exposure in H460, H460R, and H1299 cells. Our study suggests that H460R cells have differential properties, including cell morphology, potential for metastasis, and resistance to IR, compared with parental cells. In addition, SNTB2 may play an important role in radioresistance. H460R cells could be helpful in in vitro systems for elucidating the molecular mechanisms of and discovering drugs to overcome radioresistance in lung cancer therapy.

• 생명과학회지
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• 제20권2호
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• pp.176-182
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• 2010

벼의 생산에 있어 가장 큰 문제 요인 중 하나인 벼도열병의 발생 원인균인 벼도열병균은 다양한 기작에 의해 방제 약제에 대한 내성을 가지는 것으로 알려져 있다. 막 운반단백질인 ABC transporter의 경우 환경으로부터의 다양한 독성 물질들을 배출하는 것으로 알려져 있다. 이미 알려진 벼도열병균의 게놈 서열로부터 생물정보학적 분석을 통하여 ABC transporter 단백질의 도메인 특성을 보이는 33개의 유전자군 서열을 예측하였다. 이중 3개의 경우는 이미 알려진 유전자로 판명되었다. Southern Hybridization 분석에 적용한 20개의 유전자들이 모두 게놈상에 단일 copy로 존재함을 확인하였다. 새로 예측된 30개의 유전자중 11개는 RT-PCR을 통하여 전사단계에서의 유전자 발현이 확인되었다.

• 대한바이러스학회지
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• 제27권2호
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• pp.169-176
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• 1997

In this study, the feasibility of identification and genotypic differentiation of enteroviruses was investigated by using nested reverse transcription-polymerase chain reaction (nested RT-PCR), single-stranded conformation polymorphism (SSCP), and restriction fragment length polymorphism (RFLP) techniques. Two hundred seventy-four clinical samples were assayed by both nested RT-PCR and tube culture method using MRC-5 and MK cells; 58 (86.6%) out of 67 enterovirus culture-positive samples contained enteroviral RNA. In addition, 114 (55.1%) of 207 samples from patients with suspected enteroviral CNS disease with negative viral cultures were positive by the nested RT-PCR. The nested RT-PCR products were genotyped by the SSCP method and the results were compared with serotypes. We could differentiate 6 subtypes, 3 of which are similar to coxsackievirus B3, B5, echovirus 11, plus 3 other subtypes. RFLP cleaved with Sty I, Bgl I, and Xmn I yielded characteristic patterns for each laboratory strains. This study demonstrates the usefulness of the RT-PCR for the rapid diagnosis of enterovirus infection and the potentials of the SSCP method for differentiation of enterovirus strains.

• 한국동물생명공학회지
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• 제34권4호
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• pp.292-299
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• 2019

Interferon tau (IFNT) regulation, an anti-luteolytic factor produced by conceptuses of the ruminant ungulates, is essential for the maintenance of early pregnancy, but a definitive mechanism for its temporal transcription has not been elucidated. We and others have observed the T-box protein eomesodermin (EOMES) exhibited high mRNA expression in the ovine embryonic trophectoderm; thus, both caudal-relatedhomeobox-2 (CDX2) and EOMES coexist during the early stages of conceptus development. Objective of this study was to examine the effect of EOMES on ovine IFNT gene transcription when evaluated with CDX2, ETS2 and AP1 transcription factors implicated in the control of cell differentiation in the trophectoderm. In this study, quantitatively via reverse transcription-polymerase chain reaction (RT-PCR) analysis between ovine trophoblast cells was initially performed, finding that transcription factors CDX2 and 'EOMES transcription factor mRNAs' were specific to trophectoderm cells. These mRNAs were also found in days 15, 17, and 21 ovine conceptuses. Furthermore, human choriocarcinoma JEG3 cells (trophoblast cell line) were cotransfected with an ovine IFNT (-654bp)-luciferase reporter (-654-oIFNT-Luc) construct and several transcription factor expression plasmids. Cotransfection of the reporter construct with CDX2, ETS2 and AP1 increased transcription of -654-oIFNT-Luc by about 11-fold compared with transfection of the construct alone. When cells were initially transfected with EOMES followed by transfection with CDX2, ETS2 and/or AP1, the expression of -654-oIFNT-Luc was decreased. Also, EOMES factor inhibited the stimulatory activity of CDX2 alone. These results suggest that when conceptuses attach to the uterine epithelium, ovine IFNT gene transcription is down-regulated by an increase of EOMES factor expression in the attached ovine trophoblast cells.