• 제목/요약/키워드: topoisomerase

검색결과 181건 처리시간 0.022초

시프로플록사신 내성 황색 포도상 구균에서 MIC의 하향 분포로 입증된 DW-224a의 in vitro 항균 활성의 비교 우수성 (Comparative Superiority of in vitro Activity of DW-224a Supported by the Downward MIC Distribution in Ciprofloxacin-resistant Staphylococcus aureus)

  • 윤은정;이춘영;이종서;최응칠;심미자
    • Journal of Pharmaceutical Investigation
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    • 제39권6호
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    • pp.431-435
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    • 2009
  • The comparative superior in vitro activity of DW-224a was supported by the downward MIC distribution due to the weakened influence of alterations within target enzymes in ciprofloxacin-resistant Staphylococcus aureus. The MI$C_{50}$ for DW-224a was 4 $\mu$g/mL, similar to that of gemifloxacin, 8-fold less than that of sparfloxacin and 16-over-fold less than that of ciprofloxacin. We constructed combinations of amino acid changes, located at codon 80, 83 or 84 within GrlA and 84, 85 or 88 within GyrA, which were associated with MIC increase. The amino acid changes were less influential to the MIC of DW-224a compared to those of other fluoroquinolones, and it was verified from the requirement of a total of two GrlA- and two GyrA-alterations to reach the MIC of DW-224a over 32 $\mu$g/mL.

Construction and analysis of painting probe for homogeneously staining regions in human neuroblastoma cell line IMR-32

  • Park, Sun-Hwa;Kim, Ho-Chung;Chun, Yong-Hyuck
    • Journal of Genetic Medicine
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    • 제1권1호
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    • pp.45-50
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    • 1997
  • Neuroblastoma, a pediatric malignant neoplasm of neural crest origin, has a wide range of clinical virulence. The mechanisms contributing to the development of neuroblastomas are largely unclear, but non-random chromosomal changes identified over the past years suggest the involvement of genetic alterations. Amplification of the human N-myc proto-oncogene is frequently seen either in extrachromosomal double minutes or in homogeneously staining regions (HSRs) of aggressively growing neuroblastomas. N-myc maps to chromosome 2 band 24, but HSR have never been observed at this band, suggesting transposition of N-myc during amplification. We have constructed and analyzed the region-specific painting probe for HSR in neuroblastoma IMR-32 to determine the derivative chromosomes. Microdissection was performed on HSR using an inverted microscope with the help of microglass needles and an micromanipulator. We pretreated the microdissected fragments with Topoisomerase I which catalyzes the relaxation of supercolled DNA, and performed two initial rounds of DNA synthesis with T7 DNA polymerase followed by conventional PCR to enable the reliable preparation of Fluorescent in situ hybridization probe from a single microdissected chromosome. With this method, it was possible to construct the region-specific painting probe for HSR. The probe hybridized specifically to the HSRs of IMR-32, and to 2p24, 2p13 of normal chromosome. Our results suggest there was coamplification of N-myc together with DNA of the chromosome 2p24 and 2p13. Moreover, the fluorescent signals for the amplified chromosomal regions in IMR-32 cells were also easily recognized at a Thus this painting probe can be applied to detect the similar amplification of N-myc in neuroblastoma tissue, and the probe pool for HSR may be used to identify the cancer-relevant genes.

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미꾸라지의 복제원점에 대한 특성 및 구조 분석 (Characterization and DNA Structure Analysis of Replication Origin of Misgurnus mizolepis)

  • 임학섭;김무상;석영선;박상대;이형호
    • 한국양식학회지
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    • 제9권1호
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    • pp.93-100
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    • 1996
  • 물고기에서 효과적인 발현 vector의 구성을 위해, 미꾸라지 MAR로부터 ARS를 cloning하여, 그 염기서열을 분석하였다. 총 443 염기들로 구성된 미꾸라지의 ARS는 다른 여러종들의 DNA 복제원점에서 나타나는 것 처럼, AT가 풍부하고, ARS consensus sequences, topoi-somerase II consensus sequences, 그리고 A 흑은 T-box등을 포함하고 있다. 그리고 그 DNA 단편은 복제원점에서 일반적인 양상으로 나타나는 반복적인 inverted sequence들을 가지고 있고, 5개의 가능한 hairpin loop 구조들을 내포하고 있다. 이들 구조는 DNA 복제개시에 관여하는 단백질들의 인지부위로 작용할 것으로 생각된다.

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Pharmacodynamics of CKD-602 (Belotecan) in 3D Cultures of Human Colorectal Carcinoma Cells

  • Lee Sin-Hyung;Al-Abd Ahmed M.;Park Jong-Kook;Cha Jung-Ho;Ahn Soon-Kil;Kim Joon-Kyum;Kuh Hyo-Jeong
    • Biomolecules & Therapeutics
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    • 제14권2호
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    • pp.90-95
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    • 2006
  • CKD-602 exerts its antitumor effect via inhibition of topoisomerase I in cancer cells. Multicellular spheroid (MCS) and Multicellular layers (MCLs) are known as in vitro 3-dimensional models which closely represent tumor conditions in vivo. In order to investigate the potential of CKD-602 against human colorectal tumors, we evaluated the anti-proliferative activity and penetration ability of CKD-602 in MCS and MCL cultures of DLD-l human colorectal cancer cells, respectively. The maximum effects($E_{max}$) induced by CKD-602 were significantly lower in MCS compared to monolayers (48% vs 92%). With prolonged drug exposure, the $IC_{50's}$ of CKD-602 decreased to $23.5{\pm}1.0nM$ in monolayers after 24 h exposure and $42.3{\pm}1.7nM$ in MCS after 6 days, respectively. However, no further increase in effect was observed for exposure time longer than growth doubling time (Td) in both cultures. Activity of CKD-602 was significantly reduced after penetration through MCL and also with cell-free insert membrane. In conclusion, CKD-602 showed significantly decreased anti-proliferative activity in 3D cultures (MCS) of human colorectal cancer cells. Tumor penetration of CKD-602 could not be determined due to loss of activity after penetration through cell free insert membrane, which warrants further evaluation using a modified model.

Molecular Cloning of the DNA Gyrase Genes from Methylovorus Sp. Strain SS1 and the Mechanism of Intrinsic Quinolone Resistance in Methylotrophic Bacteria

  • Kim, Kwang-Seo;Kim, Jeong Hoon;Kim, Do Yeob;Kim, Hyun Jong;Park, Sang Tae;Kim, Young Min
    • Molecules and Cells
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    • 제20권3호
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    • pp.392-400
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    • 2005
  • The genes encoding the DNA gyrase A (GyrA) and B subunits (GyrB) of Methylovorus sp. strain SS1 were cloned and sequenced. gyrA and gyrB coded for proteins of 846 and 799 amino acids with calculated molecular weights of 94,328 and 88,714, respectively, and complemented Escherichia coli gyrA and gyrB temperature sensitive (ts) mutants. To analyze the role of type II topoisomerases in the intrinsic quinolone resistance of methylotrophic bacteria, the sequences of the quinolone resistance-determining regions (QRDRs) in the A subunit of DNA gyrase and the C subunit (ParC) of topoisomerase IV (Topo IV) of Methylovorus sp. strain SS1, Methylobacterium extorquens AM1 NCIB 9133, Methylobacillus sp, strain SK1 DSM 8269, and Methylophilus methylotrophus NCIB 10515 were determined. The deduced amino acid sequences of the QRDRs of the ParCs in the four methylotrophic bacteria were identical to that of E. coli ParC. The sequences of the QRDR in GyrA were also identical to those in E. coli GyrA except for the amino acids at positions 83, 87, or 95. The $Ser^{83}$ to Thr substitution in Methylovorus sp. strain SS1, and the $Ser^{83}$ to Leu and $Asp^{87}$ to Asn substitutions in the three other methylotrophs, agreed well with the minimal inhibitory concentrations of quinolones in the four bacteria, suggesting that these residues play a role in the intrinsic susceptibility of methylotrophic bacteria to quinolones.

압단자(鴨蛋子)의 항암활성(抗癌活性) 및 항전이(抗轉移) 효과(效果)에 관(關)한 연구(硏究) (Study on Antitumor Activity and Antimetastatic Effects of Bruceae Fructus(BF))

  • 이동훈;김성훈;김동희
    • 혜화의학회지
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    • 제10권2호
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    • pp.11-19
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    • 2002
  • To evaluate the antitumor activity and antimetastatic effects of Bruceae FructusCBF), studies were done experimentally. The results were obtained as follows : 1. In cytotoxicity against A549, SK-MEL-2, MCF-7 and XF498 cell concentration inhibiting cell growth up to below 50% of control was recognized at $25{\mu}g/m{\ell}$ of BF. Also BF inhibited cell growth up to below 50% of control against HCT15 cell at $12.5{\mu}g/m{\ell}$, so it showed stronger cytotoxicity against HCT15 cell than another cancer cell. 2. In Inhibitory effect on activity of DNA topoisomerase- I, the $IC_{50}$ was shown $10-50{\mu}g/m{\ell}$ of BF. 3. The T/C% was 143.4 in BF treated group in S-180 bearing ICR mice. 4. The concentration inhibiting adhesion of A549 and SK-OV-3 to complex extracellular matrix up to below 30% of control was recognized at $1{\mu}g/m{\ell}$ of BF. 5. In pumonary colonization assay, a number of colonies in the lungs were decreased significantly in BF treated group as compared with control group. These results suggested that BF extracts might be usefully applied for prevention and treatment of cancer.

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활혈대보탕(活血大補湯)의 항암활성(抗癌活性) 및 항전이(抗轉移) 효과(效果)에 관(關)한 연구(硏究) (Study on Antitumor Activity of Hwalheuldaibotang(HDBT))

  • 배문용;김동희
    • 혜화의학회지
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    • 제9권2호
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    • pp.97-109
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    • 2001
  • To evaluate the antitumor activity and antimetastatic effects of HDBT, studies were done experimentally. The results were obtained as follows: 1. HDBT extracts didn't show cytotoxicity against BALB/C mouse lung fibroblast cell. 2. In cytotoxicity against A549, SK-OV-3, B16-BL6 and HT1080 concen- tration inhibiting cell growth up to below 30% of control was recognized at $10^{-3}g/ml$ of HDBT. 3. The concentration inhibiting adhesion of A549 and B16-BL6 to complex extracellular matrix up to below 30% of control was recognized at $10^{-3}g/ml$ of HDBT. 4. In Inhibitory effect on activity of DNA topoisomerase I, the $IC_{50}$ was shown $200-300{\mu}g/m{\ell}$ of HDBT. 5. The T/C% was 137.9% in HDBT-treated group in S-180 bearing ICR mice. 6. In CAM assay, HDBT extracts inhibited angiogenesis significantly at $15{\mu}g/egg$ concentration as compared with control. 7. In pumonary colonization assay, a number of colonies in the lungs were decreased but insignificantly in HDBT-treated group as compared with control group. 8. In hematological changes in B16-BL6 injected C57BL/6, numbers of WBC were decreased significantly in HDBT-treated group but numbers PLT were increased insignificantly as compared with control. From above results it was concluded that HDBT could be usefully applied for the prevention and treatment of cancer.

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가미사삼맥문동탕(加味沙蔘麥門冬湯)이 항암활성(抗癌活性)과 방사선부작용(放射線副作用) 억제효과(抑制效果)에 미치는 영향(影響) (Study on Antitumor Activity and Radioprotective effects of Kamisasammaekmundongtang)

  • 박양춘;김병탁
    • 혜화의학회지
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    • 제8권1호
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    • pp.403-424
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    • 1999
  • To evaluate the antitumor activity, antimetastatic and radioprotective effects of Kamisasammaekmundongtang(KSMT), studies were done experimentally. The results were obtained as follows: 1. In cytotoxicity against P388, A549 and B16-F10, KSMT was not showed satisfiable cytotoxicity as compared with control. 2. In Inhibitory effect on activity of DNA topoisomerase I, KSMT has strong inhibitory effect. 3. The inhibitory effect on adhesion of A549 to complex extracellular matrix was significantly increased at 0.5mg/ml, 1mg/ml of KSMT. 4. The T/C% was 122 in KSMT treated group in S-180 bearing ICR mice. 5. In antiangiogenetic effect on CAM assay, inhibitory rate was 33% in KSMT treated group. 6. In pulmonary colonization assay, a number of colonies in the lungs were decreased significantly in KSMT treated group as compared with control group. 7. By FACS analysis of splenic leukocyte after exposure to radiation by linear accelerator, T-helper cell, B cell and macrophage in KSMT treated group were significantly increased while splenocytes were decreased in control group. 8. In histological changes of jejunum of $Bald{\setminus}C$ mice after exposure to radiation by linear accelerator, exclusion and fusion of villi were decreased as compared with control group. But in duodenum and ileum, exclusion and fusion of villi were not decreased as compared with control group. 9. WBC, PLT were increased in KSMT treated group as compared with control group after exposure to radiation by linear accelerator, but the increasing effect was not significant. Above results suggest that KSMT may be useful in prevention of cancer metastasis and protection from damage by radiotherapy. But the further study of KSMT would be demanded.

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홍삼대보탕(紅蔘大補湯)의 항암활성(抗癌活性) 및 항전이(抗轉移) 효과(效果)에 관(關)한 연구(硏究) (Study on Antitumor Activity of Hongsamdaibotang(HDT-C))

  • 김성훈;최봉균;김동희
    • 혜화의학회지
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    • 제9권1호
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    • pp.143-153
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    • 2000
  • To evaluate the antitumor activity and antimetastatic effects of Hongsam -daibotang(HDT-C), studies were done experimentally. The results were obtained as follows: 1. In cytotoxicity against A549, SK-OV-3 and B16-BL6 concentration inhibi ting cell growth up to below 30% of control was recognized at $10^{-3}g/ml$ of HDT-C. 2. The T/C% was 145.4% in HDT-C treated group in S-180 bearing ICR mice. 3. In Inhibitory effect on activity of DNA topoisomerase I, the $IC_{50}$ was shown $100-200{\mu}g/ml$ of HDT-C. 4. The expressing $TNF-{\alpha}$ was increased in HDT-C treated group as compared with control. 5. The expressing MMP-9 was decreased in HDT-C treated group as compared with control. 6. HDT-C extracts exhibited efficient adhesive effect of A549, B16-BL6 cell to complex extracellular matrix. 7. In CAM assays, angiogenesis was significantly inhibited in HDT-C treated group than control group. 8. In pumonary colonization assay, a number of colonies in the lungs were decreased significantly in HDT-C treated group as compared with control group. 9. In hematological changes in B16-BL6 injected C57BL/6, numbers of WBC and were decreased insignificantly and also those of platelet were increased insignificantly in HDT-C treated group as compared with control. 10. In the histological changes of lung in B16-BL6 injected mice, infiltration of cancer cells were inhibited effectively in HDT-C treated groups whereas many cancer cells were infiltrated into erivascular and peribronchiol of control group. These results suggested that HDT-C extracts might be usefully applied for prevention and treatment of cancer.

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Multi-Function of a New Bioactive Secondary Metabolite Derived from Endophytic Fungus Colletotrichum acutatum of Angelica sinensis

  • Ramy S. Yehia
    • Journal of Microbiology and Biotechnology
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    • 제33권6호
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    • pp.806-822
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    • 2023
  • In the current study we assessed a new crystallized compound, 5-(1-hydroxybutyl)-4-methoxy-3-methyl-2H-pyran-2-one (C-HMMP), from the endophytic fungus Colletotrichum acutatum residing in the medicinal plant Angelica sinensis for its in vitro antimicrobial, antibiofilm, antioxidant, antimalarial, and anti-proliferative properties. The promising compound was identified as C-HMMP through antimicrobial-guided fraction. The structure of C-HMMP was unambiguously confirmed by 2D NMR and HIRS spectroscopic analysis. Antimicrobial property testing of C-HMMP showed it to be effective against a variety of pathogenic bacteria and fungi with MICs ranging from 3.9 to 31.25 ㎍/ml. The compound displayed excellent antibiofilm activity against C. albicans, S. aureus, and K. pneumonia. Furthermore, the antimalarial and radical scavenging activities of C-HMMP were clearly dosedependent, with IC50 values of 0.15 and 131.2 ㎍/ml. The anti-proliferative activity of C-HMMP against the HepG-2, HeLa, and MCF-7 cell lines in vitro was investigated by MTT assay, revealing notable anti-proliferative activity with IC50 values of 114.1, 90, and 133.6 ㎍/ml, respectively. Moreover, CHMMP successfully targets topoisomerase I and demonstrated beneficial anti-mutagenicity in the Ames test against the reactive carcinogenic mutagen, 2-aminofluorene (2-AF). Finally, the compound inhibited the activity of α-glucosidase and α-amylase with IC50 values of 144.7 and 118.6 ㎍/ml, respectively. To the best of our knowledge, the identified compound C-HMMP was obtained for the first time from C. acutatum of A. sinensis, and this study demonstrated that C-HMMP has relevant biological significance and could provide better therapeutic targets against disease.