• 제목/요약/키워드: Cell free DNA

검색결과 275건 처리시간 0.028초

Label/Quencher-Free Detection of Exon Deletion Mutation in Epidermal Growth Factor Receptor Gene Using G-Quadruplex-Inducing DNA Probe

  • Kim, Hyo Ryoung;Lee, Il Joon;Kim, Dong-Eun
    • Journal of Microbiology and Biotechnology
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    • 제27권1호
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    • pp.72-76
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    • 2017
  • Detection of exon 19 deletion mutation in the epidermal growth factor receptor (EGFR) gene, which results in increased and sustained phosphorylation of EGFR, is important for diagnosis and treatment guidelines in non-small-cell lung cancer. Here, we have developed a simple and convenient detection system using the interaction between G-quadruplex and fluorophore thioflavin T (ThT) for discriminating EGFR exon 19 deletion mutant DNA from wild type without a label and quencher. In the presence of exon 19 deletion mutant DNA, the probe DNAs annealed to the target sequences were transformed into G-quadruplex structure. Subsequent intercalation of ThT into the G-quadruplex resulted in a light-up fluorescence signal, which reflects the amount of mutant DNA. Due to stark differences in fluorescence intensity between mutant and wild-type DNA, we suggest that the induced G-quadruplex structure in the probe DNA can report the presence of cancer-causing deletion mutant DNAs with high sensitivity.

Carbohydrase inhibition and anti-cancerous and free radical scavenging properties along with DNA and protein protection ability of methanolic root extracts of Rumex crispus

  • Shiwani, Supriya;Singh, Naresh Kumar;Wang, Myeong Hyeon
    • Nutrition Research and Practice
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    • 제6권5호
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    • pp.389-395
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    • 2012
  • The study elucidated carbohydrase inhibition, anti-cancerous, free radical scavenging properties and also investigated the DNA and protein protection abilities of methanolic root extract of Rumex crispus (RERC). For this purpose, pulverized roots of Rumex crispus was extracted in methanol (80% and absolute conc.) for 3 hrs for $60^{\circ}C$ and filtered and evaporated with vacuum rotary evaporator. RERC showed high phenolic content ($211{\mu}g$/GAE equivalent) and strong 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging ($IC_{50}$ = 42.86 (absolute methanol) and $36.91{\mu}g/mL$ (80% methanolic extract)) and reduced power ability. Furthermore, RERC exhibited significant protective ability in $H_2O_2/Fe^{3+}$/ascorbic acid-induced protein or DNA damage and percentage inhibition of the HT-29 cell growth rate following 80% methanolic RERC exposure at $400{\mu}g/mL$ was observed to be highest ($10.2%{\pm}1.03$). Moreover, methanolic RERC inhibited ${\alpha}$-glucosidase and amylase effectively and significantly (P < 0.05). Conclusively, RERC could be considered as potent carbohydrase inhibitor, anti-cancerous and anti-oxidant.

방사선 조사 사료를 섭취한 Mouse의 혈장, 간, 소장 점막의 과산화지질과 림프구 DNA의 산화적 손상 (Plasma, Tissue Thiobarbituric Acid Reactive Substance and Lymphocyte Oxidative DNA Damage in Mouse Fed Gamma Irradiated Diet)

  • 장현희;강명희;양재승;이선영
    • Journal of Nutrition and Health
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    • 제36권3호
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    • pp.255-261
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    • 2003
  • Food irradiation has been steadily increasing in many countries in line with increasing international trade and concerns about naturally occurring harmful contaminants in food. Although irradiation provides an excellent safeguard for the consumer by destroying almost 100% of harmful bacteria, it is necessary to ensure the safety of irradiated foods. This study was performed to investigate the effect of an irradiated diet on lipid peroxidation in the plasma, liver, small intestinal mucosa, and lymphocyte DNA damage in mice. Eight-week old ICR mice were assigned to two groups to receive either non-irradiated or irradiated (10 kGy) diets containing 20.38% fish powder and 6.06% sesame seeds for 4 weeks. The resulting changes in the degrees of lipid peroxidation were evaluated based on the level of plasma and liver thiobarbituric acid reactive substance (TBARS), transmission electron micrograph of jejunal mucosa, and free radical-induced oxidative DNA damage in lymphocytes, as measured by alkaline comet assay (single cell gel electrophoresis). The peroxide values of the gamma irradiated diet were measured every week, and the sample for comet assay was taken at the end of the four week experimental period. There was no significant difference in food efficiency ratio between the two groups. The peroxide values of the diet were immediately increased to 35.5% after gamma irradiation and kept on increasing during storage. After 4 weeks, no differences in tissue or plasma TBARS value were observed between the two groups, but epithelial cells of jejumum showed osmiophillic laminated membranous structures, considered as myelin figures,. The oxidative DNA damage expressed as tail moment (TM) increased 30% in the blood lymphocytes of the mice fed the irradiated diet. In conclusion, the comet assay sensitively detected differences in lymphocyte DNA damage after feeding with the irradiated diet for 4 weeks. However, in order to ensure the safety of irradiated foods, it would be more useful to conduct a long-term feeding regimen using an irradiated diet and examine the level of lipid peroxidation and the state of oxidative stress in a greater range of organs.

재조합 효모 세포내에서의 간염백신 생산 (The Production of HBsAg in the Recombinant Yeast Cells)

  • Park, Cha-Yong;Lee, Hei-Chan
    • 한국미생물·생명공학회지
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    • 제14권6호
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    • pp.455-460
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    • 1986
  • 간염 보균자의 혈액으로부터 Dane 입자를 분리하였다. Dane 입자의 핵으로부터 분리해낸 DNA는 $\alpha$-($^{32}$P) dNTP 존재하의 DNA 폴리머레이즈 반응 후 액체 씬틸레이션 카운터와 한천 전기영동 및 가이거 뮐러 카운터에 의하여 간염의 DNA임이 확인되었다. 간염 바이러스에 의한 감염을 막기 위한 백신으로서의 B형 간염 바이러스 표면항원을 생산하기 위하여 산성포스파테이즈 프로모터를 갖는 재조합 프라스미드를 함유하는 효모균주를 사용하였다. 재조합 프라스미드는 pHBV 130 및 pAM 82로부터 제작되었으며 대장균에 변환되어진 후 효모균주에 전달되었다. 간염 표면항원은 조절된 무기 인산 농도하에서 버크홀더 최소배지에서의 저해 해제로 생산되었다. 간염 표면항원의 생산 속도도 조사하였다. 전체 간염 표면항원 활성은 인산이 없는 배지에 옮겨진 뒤 3시간 내지 6시간에서 급격히 증가하였으며 9시간째에 최대에 도달하였다. 인산이 없는 배지에 옮기는 것은 고농도 인산 배지에서의 세포 배양을 6시간동안 수행한 뒤에 하는 것이 최적의 결과를 나타내었다.

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Chlorella 세포에서의 $^{32}P$-인산의 단백질 및 다른 질소화합물로의 전환 (Incorporation of phosphate into protein and other nitrogenous compounds in Chlorella cells)

  • Lee, Yung-nok
    • 미생물학회지
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    • 제5권2호
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    • pp.61-68
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    • 1967
  • In the process of the incorporation of orthophsphate into protein and other cell constituents, the role of inorganic polyphosphate and RNA-polyphosphate complex and the correlation between them were pursued by analyzing the contents of $^{32}P$ and total P in various fractions of Chlorella cells, which had been uniformly labeled with $^{32}P$ before the inoculation in a normal "cold" medium or P-free medium during the culture. The effects of ionizing radiation and various micronutritional-element deficiencies on the phosphate incorporation into, and biosynthesis of, protein and other introgenus compounds in the cells were also observed. When the uniformly $^{32}P$-labeled algae were grown in a normal "cold" medium the contents of $^{32}$ P in the fractions of protein, DNA and RNA-polyphosphate complex increased, but those in the fraction of acid-insoluble polyphosphate decreased. On the other hand, amount of $^{32}P$in the fraction of RNA was almost unchanged in spite of rapid increase of the total P. In the growing period of $^{32}P$-labeled algae in a P-free medium, amounts of $^{32}P$ in the fractions of DNA, protein and lipid increased, while those in the fractions of RNA-polyphosphate and inorganic polyphosphates decreased. When the algal cells were irradiated with about 70, 000r of gamma-rays before the inoculation in the medium, amounts of phosphate in the fractions of DNA, RNA, nucleotides and protein decreased during the culture, compared with those of the control. However, the phosphate content in the fraction of acid-insoluble polyphosphate of the irradiated cells increased than those of the control. In the growing period of the algae in a Mo-free, medium, amounts of acid-soluble total phosphate and nucleotides of the cells increased, while the amounts of residual protein and RNA decresed compared with those of the normal cells. Amounts of alkali-labile protein and phospholipid of the cells grown in a B-free medium decreased, whereas amount of phosphate in acid-soluble fraction increased compared with the control. In general, the contents of protein and RNA in each microelement deficient cells decreased more or less, compared with those in the normal cells.in the normal cells.

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New anti-wrinkle cosmetics

  • Lee, Kang-Tae;Lee, Sun-Young;Jeong, Ji-Hean;Jo, Byoung-Kee
    • 대한화장품학회지
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    • 제28권1호
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    • pp.71-79
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    • 2002
  • In the aged skin especially in the face and eyelid, deep and slight wrinkles are one of the remarkable phenomena of aging and the cause of wrinkle is various. Among the cause of wrinkles an oxidative stress plays an important roles in wrinkle formation process. It caused the lipid peroxidation of cell membrane, the increase of the MMPs(MatrixMetalloProteinase) gene expression and cellular DNA damage. These ROS induced materials may cause the degradation of collagen matrix system in the dermis and cause the formation of skin wrinkle. So, it is very important for protecting skin wrinkle formation to regulate ROS activity. In this study, we developed one active ingredient having multi functional activities such as activation of collagen synthesis, inhibition of MMPs activity, lipid peroxidation and free radical scavenging activity and inhibition of free radical induced DNA damage in vitro. Pericarpium castaneae extracts showed collagen synthesis increase in Normal Human Fibroblast and the inhibition of elastase activity (IC$\_$50/ of Elastase: 43.9$\mu\textrm{g}$/㎖). It showed also anti-oxidative activity (IC$\_$50/ : 48$\mu\textrm{g}$/㎖) and free radical scavenging activity(IC$\_$50/: 7.6$\mu\textrm{g}$/㎖). Conclusively, Pericarpium castaneae extracts may be used as an ingredient for new anti-wrinkle cosmetics.

Change of Insulin-like Growth Factor Gene Expression in Chinese Hamster Ovary Cells Cultured in Serum-free Media

  • Park, Hong-Woo;An, Sung-Kwan;Choe, Tae-Boo
    • Biotechnology and Bioprocess Engineering:BBE
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    • 제11권4호
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    • pp.319-324
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    • 2006
  • Although the sera used in animal cell culture media provide the macromolecules, nutrients, hormones, and growth factors necessary to support cell growth, it could also be an obstacle to the production of recombinant proteins in animal cell culture systems used in many sectors of the biotechnology industry. For this reason, many research groups, including our laboratory, have been trying to develop serum-free media (SFM) or serum-supplemented media (SSM) for special or multi-purpose cell lines. The Chinese hamster ovary (CHO) cell, for example, is frequently used to produce proteins and is especially valuable in the large-scale production of pharmaceutically important proteins, yet information about its genome is lacking. Also, SFMs have only been evaluated by comparing growth patterns for cells grown in SFMs with those grown in SSM or by measuring the titer of the target protein obtained from cells grown in each type of medium. These are not reliable methods of obtaining the type of information needed to determine whether an SFM should be replaced with an SSM. We carried out a cDNA microarray analysis to evaluate MED-3, an SFM developed in our laboratory, as a CHO culture medium When CHO cells were cultured in MED-3 instead of an SSM, several genes associated with cell growth were down-regulated, although this change diminished over time. We found that the insulin-like growth factor (IGF) gene was representative of the proteins that were down-regulated in cells cultured in MED-3. When several key supplements - including insulin, transferrin, ethanolamine, and selenium - were removed from MED-3, the IGF expression was consistently down- regulated and cell growth decreased proportionately. Based on these results, we concluded that when an SFM is used as a culture medium, it is important to supplement it with substances that can help the cells maintain a high level of IGF expression. The data presented in this study, therefore, might provide useful information for the design and development of SFM or SSM, as well as for the design of genome-based studies of CHO cells to determine how they can be used optimally for protein production in pharmaceutical and biomedical research.

국화추출물이 산화적 스트레스에 의해 유발되는 세포와 DNA 손상에 미치는 영향 (Effect of Dendranthema indicum Extracts on Cell and DNA Damage Induced by Oxidative Stress)

  • 박영미;김지인;이창호;임재환;서을원
    • 생명과학회지
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    • 제21권12호
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    • pp.1698-1704
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    • 2011
  • 본 연구는 국화추출물이 산화적 스트레스에 의한 세포와 DNA의 손상에 미치는 영향을 조사하였다. 국화추출물의 DPPH 유리 라디칼과 수산화 라디칼의 제거 활성은 $200{\mu}g$/ml에서 각각 92.8%, 73.8%로 나타났으며, $Fe^{2+}$-chelating 효과는 59.4%로 나타났다. 국화 추출물의 지질과산화 억제능은 대조군의 90.3%의 활성을 보였으며, p21 단백질의 발현 수준은 대조군의 79.6%로 나타나 라디칼 처리군에 비해 높은 것으로 조사되었다. 또한 국화추출물의 DNA 분절화 억제 활성은 대조군의 89.6%를 보였고, DNA tail의 이동은 농도에 따른 차이는 있으나 대조군과 비교적 유사한 수준으로 감소되는 경향을 나타내었으며 phospho-H2AX 단백질의 발현은 라디칼 처리군의 79.8%에 해당하는 수준을 보여 DNA 인산화를 억제하는 데 높은 활성을 나타내었다. 따라서 본 연구의 국화추출물은 산화적 스트레스에 의한 생체 내 독성으로부터 세포와 DNA를 보호하는 데 효과적으로 작용하는 천연 항산화 물질로서의 응용이 기대된다.

Protective Effect of Allomyrina dichotoma Larva Extract on tert-butyl Hydroperoxide-induced Oxidative Hepatotoxicity

  • Lee, Kyung-Jin;Lee, Jong-Bin
    • 환경생물
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    • 제27권2호
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    • pp.230-236
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    • 2009
  • An extract of Allomyrina dichotoma larva (ADL), one of the insects used most frequently in traditional Chinese medicine for the treatment of liver diseases such as hepatocirrhosis and hepatofibrosis, was assessed for antioxidant bioactivity in this study. In the current work, we have investigated the protective effects of ADL extracts on tert-butyl hydroperoxide (t-BHP)-induced hepatotoxicity in cultured hepa1c1c7 cells and in the mouse liver. The treatment of the hepa1c1c7 cells with ADL extracts induced a significant reduction of t-BHP-induced oxidative injuries, as determined by cell cytotoxicity, lipid peroxidation (LPO) and reactive oxygen species contents, in a dose-dependent manner. Moreover, ADL extracts evidenced a protective effect against t-BHPinduced oxidative DNA damage, as revealed by the results of the Comet assay in hepa1c1c7 cells. ADL extracts also protected against hydroxyl radical-induced 2-deoxy-d-ribose degradation by ferric ion-nitrilotriacetic acid and $H_2O_2$. In addition, ADL extracts were shown to be able to quench 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radicals. Our in vivo study revealed that ADL extracts pretreatment applied prior to t-BHP administration significantly prevented an increase in the serum levels of hepatic enzyme markers and reduced LPO in the mouse liver in a dose-dependent manner. Taken together, these results suggest that the protective effects of ADL extracts against t-BHP-induced hepatotoxicity may be attributable, at least in part, to its ability to scavenge free oxygen radicals, and to protect against DNA damage due to oxidative stress.

Targeting HSP90 Gene Expression with 17-DMAG Nanoparticles in Breast Cancer Cells

  • Mellatyar, Hassan;Talaei, Sona;Nejati-Koshki, Kazem;Akbarzadeh, Abolfazl
    • Asian Pacific Journal of Cancer Prevention
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    • 제17권5호
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    • pp.2453-2457
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    • 2016
  • Background: Dysregulation of HSP90 gene expression is known to take place in breast cancer. Here we used D,L-lactic-co-glycolic acid-polyethylene glycol-17-dimethylaminoethylamino-17-demethoxy geldanamycin (PLGA-PEG-17DMAG) complexes and free 17-DMAG to inhibit the expression of HSP90 gene in the T47D breast cancer cell line. The purpose was to determine whether nanoencapsulating 17DMAG improves the anti-cancer effects as compared to free 17DMAG. Materials and Methods: The T47D breast cancer cell line was grown in RPMI 1640 supplemented with 10% FBS. Encapsulation of 17DMAG was conducted through a double emulsion method and properties of copolymers were characterized by Fourier transform infrared spectroscopy and H nuclear magnetic resonance spectroscopy. Assessment of drug cytotoxicity was by MTT assay. After treatment of T47D cells with a given amount of drug, RNA was extracted and cDNA was synthesized. In order to assess HSP90 gene expression, real-time PCR was performed. Results: Taking into account drug load, IC50 was significant decreased in nanocapsulated 17DMAG in comparison with free 17DMAG. This finding was associated with decrease of HSP90 gene expression. Conclusions: PLGA-PEG-17DMAG complexes can be more effective than free 17DMAG in down-regulating of HSP90 expression, at the saesm time exerting more potent cytotoxic effects. Therefore, PLGA-PEG could be a superior carrier for this type of hydrophobic agent.