• Journal of Microbiology and Biotechnology
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• 제8권1호
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• pp.89-91
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• 1998

Cryptotanshinone induced topoisomerase I-mediated DNA cleavage in vitro as strongly as camptothecin, whereas topoisomerase II-mediated DNA cleavage was not induced by this agent. In DNA relaxation assay using calf thymus DNA topoisomerase I and supercoiled pBR322 DNA, cryptotanshinone inhibited topoisomerase I-mediated DNA relaxation in a dose-dependent manner. In unwinding assay, cryptotanshinone ($50{\mu}M$) did not shift the topoisomers of DNA. These results suggest that cryptotanshinone exerted a preferential inhibition of topoisomerase I without intercalating into DNA.

• 약학회지
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• 제47권3호
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• pp.125-129
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• 2003

A series of 2-phenyl-5-nitrobenzimidazoles substituted at the para positon of the 2-phenyl moiety was synthesized ＆ evaluated for their activity to inhibit topoisomerase I. The structure-activity relationship study revealed that neither the electronic nor lipophilic parameters were related to the topoisomerase I inhibition. A strict spatial requirement seems to be present for retention of topoisomerase I inhibition activity.

• Journal of Microbiology and Biotechnology
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• 제12권6호
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• pp.1013-1016
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• 2002

Cyclo(L-prolyl-L-phenylalanyl) [cyclo(pro-phe)] was isolated from Streptomyces sp. AMLK-335 and found to inhibit DNA topoisomerase I activity. In a DNA relaxation assay using supercoiled pBR322 DNA, cyclo(pro-phe) inhibited the DNA topoisomerase activity more strongly than camptothecin, a known topoisomerase inhibitor. However, at a concentration of $10{\mu}M$, cyclo(pro-phe) produced a lower degree of DNA relaxation than camptothecin, therefore, the inhibition of topoisomerase I activity by cyclo(pro-phe) was also found to be dose dependent. Accordingly, the current results suggest that cyclo(pro-phe) may be a novel inhibitor of topoisomerase I.

• 약학회지
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• 제44권4호
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• pp.358-361
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• 2000

Parameter focusing on the DNA topoisomerase-Iinhibition with X-substituted phenyl substituents in 1-(2-furyl)-3-phenylpropenone derivatives as inhibition material were analyzed. From the basis on the results the inhibition on DNA topoisomerase I suggested that the inhibition activities of X-substituted phenyl substitutents would depend largely on the net charge of $\beta$-carbon atom, LUMO energy (e.v.) and STERIMOL parameter B$_{5}$ (width) of X. Among them, non-substituent (X=H), 1 and 2,2-dichloro substituent, 4 showed the highest DNA topoisomerase-I inhibition activity.y.

• 생명과학회지
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• 제18권1호
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• pp.75-83
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• 2008

인체 DNA topoisomerase는 DNA를 단일 또는 두 가닥을 일시적인 절단을 촉매하여 DNA의 topological 문제를 조절함으로써, DNA 복제, 전사, 재조합과 유사분열 과정 등에 관여한다. 이 효소는 많은 항생, 항암제의 표적효소로서 널리 알려져 있으며, 이들 유도체를 이용한 다양한 억제제의 개발과 임상적 응용에 관한 연구가 활발하게 진행되고 있다. 본 실험에서는 인체 백혈병 HL-60 세포에서 topoisomerase 억제제가 topoisomerase 기능 활성과 유전자 발현을 조절하는지를 규명하기 위하여 본 연구를 수행하였다. 연구 방법은 HL-60세포에 topoisomerase type I과 type II의 대표적 억제제인 10-hydroxycamptothecin (10-CPT)과 doxorubicin을 투여한 후 total RNA를 분리하였고, 10K-oligo-nucleotide microarray 방법으로 분석하여 유전자의 발현 양상을 조사하였다. 연구 결과에 의하면 10-CPT 또는 doxorubicin을 투여한 HL-60세포에서의 유전자 발현 양상은 주로 signal transduction, cell adhesion, cell cycle, cell growth, cell proliferation, cell differentiation, transcription 및 immune response 등과 관련이 있었다. Topoisomerase type I의 억제제인 10-CPT를 HL-60 세포주에 투여 하였을 때 type I으로 분류되는 topoisomerase III${\alpha}$, III${\beta}$ 및 I의 발현은 증가하였으나 type II인 topoisomerase II${\alpha}$와 II${\beta}$의 유전자의 발현은 감소되었다. 반대로 type II의 억제제인 doxorubicin을 투여하였을 때는 앞의 결과와 상반된 topoisomerase II${\alpha}$와 II${\beta}$의 유전자의 발현이 현저히 증가되었으며, topoisomerase III${\alpha}$와 III${\beta}$의 mRNA의 발현은 약간 감소하는 양상을 보였으나 의미 있는 차이는 없었다. 이 연구 결과는 앞으로 항암제의 기전을 밝히고 약물에 대한 치료 반응을 예측하고 새로운 약제 개발에 기초자료가 될 것으로 여겨진다.

• Biomolecules & Therapeutics
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• 제29권5호
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• pp.562-570
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• 2021

Topoisomerase IIα has been a representative anti-cancer target for decades thanks to its functional necessity in highly proliferative cancer cells. As type of topoisomerase IIα targeting drugs, topoisomerase II poisons are frequently in clinical usage. However, topoisomerase II poisons result in crucial consequences resulted from mechanistically induced DNA toxicity. For this reason, it is needed to develop catalytic inhibitors of topoisomerase IIα through the alternative mechanism of enzymatic regulation. As a catalytic inhibitor of topoisomerase IIα, AK-I-191 was previously reported for its enzyme inhibitory activity. In this study, we clarified the mechanism of AK-I-191 and conducted various types of spectroscopic and biological evaluations for deeper understanding of its mechanism of action. Conclusively, AK-I-191 represented potent topoisomerase IIα inhibitory activity through binding to minor groove of DNA double helix and showed synergistic effects with tamoxifen in antiproliferative activity.

• 한국식품영양과학회지
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• 제29권5호
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• pp.917-921
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• 2000

This study was carried out to investigate the effects on the mutagenicity and activity of DNA topoisomerase I of Sarcodon aspratus. Using an Ames mutagenicity test, which has been used to assess both mutagenic and antimutagenic effects of various molecules, it was observed that the methanol extracted fraction and other fractions (prepared in water or ethylacetate) of Sarcodon aspratus showed a significant antimutagenic activity against a mutagenecity induced by both a direct mutagenic agent such as MNNG and an indirect mutagenic agents such as B(a)P and AFB$_1$in Salmonella typhimurium TA98, TA100. Also, the extract and fractions of Sarcodon aspratus were found to have an inhibitory activity on the relaxation process of DNA topoisomerase I.

• 한국미생물·생명공학회지
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• 제23권2호
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• pp.123-130
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• 1995

DNA topoisomerase I have been shown to be important therapeutic target in cancer chemotherapy. Chemotaxonomy and numerical identification were carried out for an isolate strain No.7489 producing an antibiotic that inhibits DNA topoisomerase I activity. The genus of strain No.7489 was determined as Streptomyces sp. from culture, morphological and chemotaxonomic data. Thirty-nine taxonomic unit characters were tested and the data were analyzed numerically using the TAXON program. The isolate was best matched to Streptomyces melanosporofaciens in the major cluster 32 of Streptomyces. Therefore, it was concluded that the isolate was identified to be a member of Streptomyces melanosporofaciens.

• Journal of Microbiology and Biotechnology
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• 제10권3호
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• pp.394-398
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• 2000

A methanol extract of the root of Peucedanum japonicum, used as a medicinal herb, showed an inhibitory effect on mammalian topoisomerase I activity. The methanol extract was suspended in ethyl acetate, and a topoisomerase I inhibitor in the organic soluble fraction was then isolated by silica gel and thin layer chromatography. The topoisomerase I inhibitory compound was indentified as falcarindiol based on the analysis of EI-MS, $^1$H and \ulcornerC NMR spectroscopy. This inhibitory showed cytotoxicity against human leukemia Jurkat T and HL60 cells with an IC\ulcorner value of 7 $\mu\textrm{g}$/ml. These results suggest the possibility of falcarindiol as a new anticancer agent which can be expected to have a synergistic effect on other anticancer drugs. In addition, the present data show that falcarindiol has antifungal, yet not antibacterial, activity.

• Applied Biological Chemistry
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• 제43권3호
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• pp.228-230
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• 2000