• 한국환경생물학회:학술대회논문집
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• 한국환경생물학회 2002년도 학술대회
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• pp.145-153
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• 2002

유해 화학 물질류에 의해 오염된 해양 환경 시료의 환경독성 수준을 평가하기 위하여 다양한 화학물질에 대해 민감성이 우수한 생물학적 독성평가기법을 개발 하고자하였다. 지속성 유기오염 물질 중 다환 방향 족 탄화수소(PAHs)를 처리한 광어(Conger myriaster)와 개조개(Saxidomus pupurata)의 DNA 손상정도를 single cell gel electrophoresis assay(comet assay)를 통해 분석하였다. PAHs 중 광양만에서 높은 농도로 검출되는 benzo(a)pyrene을 농도별(0, 10, 50, 100 ppb)로 처리한 후 2일과 4일에 광어의 혈액세포와 개조개의 근육세포를 채취해 comet assay를 실시하였다. benso(a)pyrene에 대한 DNA 손상정도를 처리된 농도와 생물종에 따라 다르게 나타났는데 광어의 혈액세포는 2일에 가장 DNA 손상정도가 높았고, 4일에는 회복되는 경향을 나타냈다. 개조개의 근육세포는 시간이 지나면서 DNA 손상정도가 증가하는 경향을 보였다. 이와 같은 결과는 comet assay 기법이 유해 화학물질로 오염된 해양생물 종의 환경독성을 검색하는 유용한 수단이 될 수 있음을 보여준다.

• Journal of Preventive Medicine and Public Health
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• 제37권4호
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• pp.373-380
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• 2004

Objectives : There has been gradually increasing concern about the adverse health effects of electromagnetic radiation originating from cell phones which are widely used in modern life. Cell phone radiation may affect human health by increasing free radicals of human blood cells. This study has been designed to identify DNA damage of blood cells by electromagnetic radiation caused by cell phone use. Methods : This study investigated the health effect of acute exposure to commercially available cell phones on certain parameters such as an indicator of DNA damage for 14 healthy adult volunteers. Each volunteer during the experiment talked over the cell phone with the keypad facing the right side of the face for 4 hours. The single cell gel electrophoresis assay (Comet assay), which is very sensitive in detecting the presence of DNA strand-breaks and alkali-labile damage in individual cells, was used to assess peripheral blood cells (T-cells, B-cells, granulocytes) from volunteers before and after exposure to cell phone radiation. The parameters of Comet assay measured were Olive Tail Moment and Tail DNA %. Results : The Olive Tail Moment of B-cells and granulocytes and Tail DNA % of B-cells and granulocytes were increased by a statistically significant extent after 4-hour use of a cell phone compared with controls. Conclusion : It is concluded that cell phone radiation caused the DNA damage during the 4 hours of experimental condition. Nonetheless, this study suggested that cell phone use may increase DNA damage by electromagnetic radiation and other contributing factors.

• The Korean Journal of Physiology and Pharmacology
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• 제16권3호
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• pp.153-158
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• 2012

Cellular effects of ethanol in YD-15 tongue carcinoma cells were assessed by MTT assay, caspase activity assay, Western blotting and flow cytometry. Ethanol inhibited the growth and proliferation of YD-15 cells in a dose- and time-dependent manner in an MTT assay. The effects of ethanol on cell cycle control at low percent range of ethanol concentration (0 to 1.5%), the condition not inducing YD-15 cell death, was investigated after exposing cells to alcohol for a certain period of time. Western blotting on the expression of cell cycle inhibitors showed that p21 and p27 was up-regulated as ethanol concentration increases from 0 to 1.5% whilst the cell cycle regulators, cdk1, cdk2, and cdk4 as well as Cyclin A, Cyclin B1 and Cyclin E1, were gradually down-regulated. Flow cytometric analysis of cell cycle distribution revealed that YD-15 cells exposed to 1.5% ethanol for 24 h was mainly arrested at G2/M phase. However, ethanol induced apoptosis in YD-15 cells exposed to 2.5% or higher percent of ethanol. The cleaved PARP, a marker of caspase-3 mediated apoptosis, and the activation of caspase-3 and -7 were detected by caspase activity assay or Western blotting. Our results suggest that ethanol elicits inhibitory effect on the growth and proliferation of YD-15 tongue carcinoma cells by mediating cell cycle arrest at G2/M at low concentration range and ultimately induces apoptosis under the condition of high concentration.

• 한국환경성돌연변이발암원학회지
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• 제21권1호
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• pp.34-43
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• 2001

Di-2-ethylhexyl phthalate (DEHP) is the most commonly used phthalate ester in polyvinyl chloride formulations including food packing and storage of human blood. DEHP is a well known as non-genotoxic carcinogen and endocrine disrupting chemical (EDC). DEHP have shown all negative results in ICH-guildeline recommended standard genotoxicity test battery. In this study, to assess the clastogenic and DNA damaging effect in human-derived tissue specific cells, DEHP was treated in human derived MCE-7 cells, HepG2 cells, LNCap cells, BeWo cells, MCE-10A cells, and female peripheral blood cells using micronucleus assay and in human breast carcinoma MCF-7 cells up to $1.28$\times$10^{-2}$ M using Comet assay. The in vitro micronucleus assay is a mutagenicity test system for the detection of chemicals which induce the formation of small membrane bound DNA fragment i.e. micronuclei in the cytoplasm of interphase cells, originated from clastogenic and/or aneugenic mechanism. The single cell gel electrophoresis assay (Comet assay) is used to detect DNA strand-breaks and alkaline labile site. In our results, DEHP increased significantly and/or dose-depentently and time-dependently micronucleus frequency at the 6 and 24 hr without metabolic activation system only in MCE-7 cells. DEHP treated with 2 hrs in MCF-7 cells using Comet assay induced DNA damage dose-depentantly.

• BMB Reports
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• 제41권7호
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• pp.511-515
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• 2008

The nucleocapsid (NC) protein of the Human Immunodeficiency Virus-1 plays a key role in viral genomic packaging by specifically recognizing the Psi($\Psi$) RNA sequence within the HIV-1 genome RNA. Recently, a novel cell-based assay was developed to probe the specific interactions in vivo between the NC and $\Psi$-RNA using E.coli cells (J. Virol. 81: 6151-55, 2007). In order to examine the extendibility of this cell-based assay to RNAs other than $\Psi$-RNA, this study tested the RNA aptamers isolated in vitro using the SELEX method, but whose specific binding ability to NC in a living cellular environment has not been established. The results demonstrate for the first time that each of those aptamer RNAs can bind specifically to NC in a NC zinc finger motif dependent manner within the cell. This confirms that the cell-based assay developed for NC-$\Psi$interaction can be further extended and applied to NC-binding RNAs other than $\Psi$-RNA.

• Asian Pacific Journal of Cancer Prevention
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• 제15권2호
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• pp.617-622
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• 2014

Voacanga globosa (Blanco), a plant endemic to the Philippines, is traditionally used especially by indigenous people of Bataan in the treatment of ulcers, wounds and tumorous growths. This study aimed to provide scientific evidence to therapeutic properties by determining cytotoxic and pro-apoptotic activity of HPLC fractions from leaves on HCT116 human colon carcinoma and A549 human lung carcinoma cell lines. Ethanolic extraction was performed on V globosa leaves followed by hexane and ethyl acetate partitioning. Silica gel column chromatography and high performance liquid chromatography (HPLC) produced MP1, MP2 and MP3 fractions. Cytotoxic activity of the fractions was determined through MTT assay against the cancer cell lines HCT116 and A549 and the non-cancer AA8 Chinese hamster ovarian cell line. Pro-apoptotic activities of the most active fractions were further assessed through DAPI staining, TUNEL assay and JC-1 mitochondrial membrane potential assay with HCT116 cells. While the MPI fraction exerted no significant activity against all cell lines tested, MP2 and MP3 fractions demonstrated high toxicity against HCT116 and A549 cells. The MP3 fraction induced formation of apoptotic bodies, condensed DNA and other morphological changes consistent with apoptosis of HCT116 cells and TUNEL assay showed significant increase in DNA fragmentation over time. In these cells, the MP3 fraction also induced mitochondrial membrane destabilization, which is generally associated with the beginning of apoptosis. Phytochemical analysis demonstrated the presence only of saponins and terpenoids in the MP3 fraction. The results indicate that the MP3 fraction exerts cytotoxic activity on HCT116 cells via induction of apoptosis triggered by loss of mitochondrial membrane potential crucial for cell survival.

• Molecular & Cellular Toxicology
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• 제2권3호
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• pp.151-158
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• 2006

Khal was a synthetic congener of halocidin, a heterodimeric peptide consisting of 19 and 15 amino acid residues detected in Halocynthia aurantium. This compound was considered a candidate for the development of a novel peptide antibiotic. The genotoxicity of Khal was subjected to high throughput toxicity screening (HTTS) because they revealed strong antibacterial effects. Mouse lymphoma thymidine kinase ($tk^{+/-}$) gene assay (MOLY), single cell gel electrophoresis (Comet) assay and chromosomal aberration 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 Khal was determined the concentration of $25.51\;{\mu}/mL\;and\;21.99\;{\mu}g/mL$ with and without S-9, respectively. In the comet assay, Khal was not induced DNA damage in mouse lymphoma cell line. Also, the mutation frequencies in the Khal-treated cultures were similar to the vehicle controls. It is suggests that Khal is non-mutagenic in MOLY assay. And no clastogenicity was observed in Khal-treated Chinese hamster lung cells. The results of this battery of assays indicate that Khal has no genotoxic potential in bacterial or mammalian cell systems. Therefore, we suggest that Khal, as the optimal candidates with both no genotoxic potential and antibacterial effects must be chosen.

• KSBB Journal
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• 제25권4호
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• pp.344-350
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• 2010

This paper demonstrates a microfluidic chip incorporating patterned hollow silica beads that can be effectively used for chemotaxis assay. The hollow silica bead has been exploited to develop a carrier for chemoattractant to induce cell migration. The microfluidic chip contains a patterned array of microfabricated docks which can hold only one bead per docking site. The hollow bead placed inside microfluidic chip releases chemotactic reagent (PDGF-BB) around its periphery in a controlled fashion which generates a signal for chemotatic migration of fibroblast cells. The number of cells migrated close to each bead has been assessed. On-chip cell migration assay showed a remarkable result proving the high efficiency and reliable accuracy in quantitative analysis. Therefore, the device could be extensively used in cell migration assay and other various studies related to cellular movements.

• 대한본초학회지
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• 제21권2호
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• pp.121-127
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• 2006

Objectives : Nickel is a major metal used in the nickel-chromium alloys of most orthodontic appliances, partial denture and implants. This study was carried out for the examination of the cytotoxicity on nickel sulfide in cultured NIH3T3 fibroblasts, and poncirin effect on nickel-induced cytotoxicity. Methods : Cell viability for the MTT assay and cell adhesion activity for the XTT assay. Results : The $IC_{50}$ of nickel sulfide by the MTT assay was $93.7\;{\mu}M$. Poncirin was significantly increased the cell viability and cell adhesion activity. Conclusion : Nickel was highly toxic and poncirin has the inhibitory effects against nickel induced cytotoxicity.

• Animal cells and systems
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• 제13권2호
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• pp.97-103
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• 2009

Recently, great advance is achieved in the field of genome-wide functional screening using cell-based assay. Here, we briefly introduce well-established and typical cell-based assays of GPCR and some parameters which should be considered for genome-wide functional screening. Because of characters and importance of GPCR as drug targets, several ways of assay systems were devised. Among them, high-content screening (HCS) that is based on the analysis of image by confocal microscope is becoming favorite choice. The advances in this technology have been driven exclusively by industry for their convenience. Now, it is turn for academy to define more detail signaling networks via HCS using cDNA or siRNA libraries at genome-wide level. By isolating novel signaling mediators using cDNA or siRNA library, and postulating them as new candidates for therapeutic target, more understanding about life science and more increased chances to develop therapeutics against human disease will be achieved.