• Title, Summary, Keyword: topoisomerase $II{\alpha}$

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Mapping of the Interaction Domain of DNA Topoisomerase $II{\alpha}$ and $II{\beta}$ with Extracellular Signal-Regulated Kinase 2

  • Park, Gye-Hwa;Bae, Young-Seuk
    • BMB Reports
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    • v.34 no.1
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    • pp.85-89
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    • 2001
  • Both topoisomerase $II{\alpha}$ and $II{\beta}$ east as phosphoproteins in the cells. Recently it was reported that DNA topoisomerase $II{\alpha}$ associates with and is phosphorylated by the extracellular signal-regulated kinase 2 (ERK2). Also, ERK2 stimulates the activity of topoisomerase II by a phosphorylation-independent manner [Shapiro et al., (1999) Mol. Cell. Biol. 19, 3551-3560]. In this study, a yeast two-hybrid system was used to investigate the binding site between topoisomerase $II{\alpha}$ or $II{\beta}$ and ERK2. The two-hybrid test clearly showed that topoisomerase $II{\beta}$ residues 1099-1263, and topoisomerase $II{\alpha}$ residues 1078-1182, mediate the interaction with ERK2, and that the leucine zipper motifs of topoisomerase $II{\alpha}$ and $II{\beta}$ are not required for its physical binding to ERK2. Our results suggest that topoisomerase $II{\beta}$ residues 1099-1263, and topoisomerase $II{\alpha}$ residues 1078-1182, may be common binding sites for activator proteins.

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Effects of Inhibitors on the Function and Activity of Topoisomerase, and Gene Expression in HL-60 Human Leukemia Cells (HL-60 세포의 유전자 발현 및 topoisomerase의 기능 활성에 미치는 억제제의 영향)

  • Jeong, In-Cheol;Cho, Moo-Youn;Park, Jang-Su
    • Journal of Life Science
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    • v.18 no.1
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    • pp.75-83
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    • 2008
  • This studies were designed to elucidate whether inhibitors of topoisomerase regulate function and activity of topoisomerase, and gene expression in HL-60 human leukemia cells. HL-60 cells were treated with 10-hydroxycamptothecin or doxorubicin, total RNA was isolated, and expressed genes were investigated with human oligonucleotide microarray containing 10K gene, respectively. Expression profiles of the human leukemia HL-60 cells treated with 10-hydroxycamptothecin (10-CIT) or doxorubicin associated with signal transduction,. cell adhesion, cell cycle, cell growth, cell proliferation, cell differentiation, transcription and immune response, especially genes related with transcription and cell growth. In HL-60 cells treated with 10-CPT, the expression of topoisomerase III${\alpha}$, III${\beta}$ and I gene from oligo chip microarray analysis were increased over, but the expression of topoisomerase II${\alpha}$ and II${\beta}$ gene were decreased over. In contrast, the expression of topoisomerase II${\alpha}$ and II${\beta}$ gene were increased over in HL-60 cells treated with doxorubicin, whereas the expression of topoisomerase III${\alpha}$ and III${\beta}$ mRNA remained no significant change. These results suggest that these data may be useful for novel therapeutic markers.

Arctigenin Inhibits Etoposide Resistance in HT-29 Colon Cancer Cells during Microenvironmental Stress

  • Yoon, Sae-Bom;Park, Hae-Ryong
    • Journal of Microbiology and Biotechnology
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    • v.29 no.4
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    • pp.571-576
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    • 2019
  • Microenvironmental stress, which is naturally observed in solid tumors, has been implicated in anticancer drug resistance. This tumor-specific stress causes the degradation of topoisomerase $II{\alpha}$, rendering cells resistant to topoisomerase $II{\alpha}$-targeted anticancer agents. In addition, microenvironmental stress can induce the overexpression of 78kDa glucose regulated protein (GRP78), which can subsequently block the activation of apoptosis induced by treatment with anticancer agents. Therefore, inhibition of topoisomerase $II{\alpha}$ degradation and reduction in GRP78 expression may be effective strategies for inhibiting anticancer drug resistance. In this study, we investigated the active compound arctigenin, which inhibited microenvironmental stress-induced etoposide resistance in HT-29 cells. Arctigenin was also highly toxic to etoposide-resistant HT-29 cells, with an $IC_{50}$ value of $10{\mu}M$ for colony formation. We further showed that arctigenin inhibited the degradation of topoisomerase $II{\alpha}$ and reduced the expression of GRP78. Thus, these results suggest that arctigenin is a novel therapeutic agent that inhibits resistance to etoposide associated with microenvironmental stress conditions.

RTP1, a Rat Homologue of Adenovirus ElA-associated Protein BS69, Interacts with DNA Topoisomerase II

  • Oh, Misook;Rha, Geun-Bae;Yoon, Jeong-Ho;Sunwoo, Yang-Il;Hong, Seung-Hwan;Park, Sang-Dai
    • Animal cells and systems
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    • v.6 no.3
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    • pp.277-282
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    • 2002
  • Topoisomearse II is an essential enzyme in all organisms with several independent roles in DNA metabolism. Recently, it has been demonstrated that the C-terminal region of topoisomerases II is associated with hetero-logous protein-protein interactions in human and yeast. In this study, we identified that RTP1, a rat homologue of EIA binding protein BS69, is another topoisomerae II interacting protein by yeast two-hybrid screening. RTP1 has an E1A-binding domain and a MYND motif, which are known to be required for transcriptional regulation by binding to other proteins and interaction with the leucine zipper motif of topoisomerase II. The physical interaction between RTP1 and topoisomerase ll$\alpha$ was examined by GST pull-down assay in vitro. The expression level of RTP1 peaks in S phase as that of topoisomerase ll$\alpha$. These results suggest that the interaction between topoisomerase ll$\alpha$ and RTP1 might play an important role in regulating the transcription of genes involved in DNA metabolism in higher eukaryotes.

M Phase-Specific Phosphorylation of DNA Topoisomerase IIα in HeLa Cells

  • Bae, Young-Seuk;Lee, Sook-Ja;Kwak, Sang-Soo
    • BMB Reports
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    • v.29 no.1
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    • pp.27-31
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    • 1996
  • Using topoisomerase II (topo II) isozyme-specific antibodies, we investigated the phosphorylation of topo $II{\alpha}$ in mitotic HeLa cells. Topo $II{\alpha}$ was specifically modified in the mitotic cells, resulting in slow migration on SDS-polyacrylamide gel electrophoresis. To characterize the nature of this modification, we treated the nuclear extracts prepared from the mitotic cells with alkaline phosphatase. After the treatment with alkaline phosphatase, the slowly migrated band disappeared and instead a normal (170 kDa) topo $II{\alpha}$ band appeared. These results indicate that human topo $II{\alpha}$ is modified at a specific site(s) in M phase by phosphorylation, supporting the possibility that M phase-specific phosphorylation of topo II is critical for mitotic chromosome condensation and segregation.

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Epidermal Growth Factor Decreases the Level of DNA Topoisomerase $II{\alpha}$ in Human Carcinoma A431 Cells

  • Chang, Jong-Soo
    • BMB Reports
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    • v.31 no.3
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    • pp.245-248
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    • 1998
  • Human epidermoid carcinoma A431 cells have an extraordinarily large number of epidermal growth factor (EGF) receptors, and their growth is inhibited by EGF, which results in growth arrest at the Gl phase. In order to investigate the EGF-mediated inhibition mechanism, the expression level of DNA topoisomerase (topo) II was analyzed after EGF treatment. As a result, it was shown that EGF treatment lowered the amount of 170 kDa topo II (topo $II{\alpha}$) but not 180 kDa (topo $II{\beta}$). However, the A431 cell variant resistant to EGF was not sensitive to EGF treatment. These results suggest that EGF-induced growth arrest of A431 cells may be closely related to the depletion of topo $II{\alpha}$.

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Effect of TNF-$\alpha$ Gene Transfer to Respiratory Cancer Cell Lines on Sensitivity to Anticancer drugs (호흡기계암세포주에서 TNF-$\alpha$ 유전자의 이입이 항암제 감수성에 미치는 효과)

  • Mo, Eun-Kyung;Lee, Jae-Ho;Lee, Kye-Young;Yoo, Chul-Gyu;Kim, Young-Whan;Han, Sung-Koo;Shim, Young-Soo;Choi, Hyung-Seok
    • Tuberculosis and Respiratory Diseases
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    • v.42 no.3
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    • pp.302-313
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    • 1995
  • Background: Tumor necrosis factor(TNF) showed antitumor cytolytic effects on sensitive tumor cells in numerous in vivo and in vitro studies. But it could not be administered systemically to human because of severe systemic adverse effects at effective concentrations against tumor cells. Many studies showed that a high concentrations of TNF in the local milieu may evoke in vivo TNF-responsive mechanisms sufficient to suppress tumor growth. Recently developed technique of TNF gene transfer to tumor cells using retrovirus vector could be a good candidate for local TNF administration. TNF is also known to synergistically enhance in vitro cytotoxicity of chemotherapeutic drugs targeted to DNA topoisomerase II against TNF-sensitive tumor cell lines. In this study the in vitro chemosensitivity against DNA topoisomerase II targeted chemotherapeutic drugs was evaluated using some respiratory cancer cell lines to which TNF gene had been transferred. Method: NCI-H2058, a human mesothelioma cell line, A549, a human lung adenocarcinoma cell line and WEHI 164 cell line, a murine fibrosarcoma cell line were treated with etoposide and doxorubicin, which are typical topoisomerase II - targeted chemotherapeutic agents, at different concentration. The resultant cytotoxicity was measured by MIT assay. Then the cytotoxicity of the same chemotherapeutic agents was measured after TNF-$\alpha$ gene-transfer and the two results were compared. Results: The cytotoxicity was not increased significantly in WEHI164 cell line and A549 cell line but statistically significant increase was observed in H2058 cell line when TNF-$\alpha$ gene was transferred(p<0.05). Conclusion: These findings show that TNF-$\alpha$ gene transfer to respiratory cancer cell lines results in variable effects on chemosensitivity against topoisomerase II inhibitor among different cell lines in vitro and can be additively cytotoxic in certain selective tumor cell lines.

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The Identification of Type II DNA Topoisomerase-Associated Protein Kinase Activity from Regenerating Rat Liver (재생 쥐간에서 분리한 DNA topoisomerase II에 결합된 protein kinase 활성)

  • 이치건;박세호;남궁록;김찬길;박상대
    • The Korean Journal of Zoology
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    • v.36 no.3
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    • pp.367-372
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    • 1993
  • We have found a protein kinase activity that is tightly associated with type II DNA topoisomerase purified from regenerating rat liver. The activities of protein kinase and topoisomerase II were not separable when the enzyme was subjected to analytical chromatographies (Hydroxyapatite, phosphocellulose, and double strand DNA cellulose) and glycerol gradient sedimentation. The kinase activity from purified rat topoisomerase II was also inactivated by the topoisomerase II inhibitors such as N-ethylmaleimide or novobiocin. The evidences, however, do not rule out a possibility that the kinase activity resides in a polypeptide other than the topoisomerase II protein. The topoisomerase II-associated protein kinase required Mg++ for its activity, and this requirement was not substituted by any other mono- or divalent ions. Histone H1 act as a strong stimulator and a good substrate for the kinase activity and other histones and ${\alpha}$-casein could not substitute the effect of histone H1.

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[ ${\alpha}$ ]-Amyrin Triterpenoids and Two Known Compounds with DNA Topoisomerase I Inhibitory Activity and Cytotoxicity from the Spikes of Prunella vulgaris var. lilacina

  • Byun, Soon-Jung;Fang, Zhe;Jeong, Su-Yang;Lee, Chong-Soon;Son, Jong-Keun;Woo, Mi-Hee
    • Natural Product Sciences
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    • v.13 no.4
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    • pp.359-364
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    • 2007
  • Three known ${\alpha}$-amyrin triterpenoids, ursolic acid (1), $2{\alpha},3{\alpha}$-dihydro xyurs-12-ene-28-oic acid (2) and euscaphic acid (3), and ${\beta}$-amyrin triterpenoid, $3{\beta}$-hydroxyolean-5,12-diene (4), and ${\alpha}$-spinasterol (5) have been isolated from the fractionated n-butanol extracts of the spikes of Prunella vulgaris var. lilacina, guided by DNA topoisomerases I and II inhibitory activities and cytotoxic activity against human cancer cells. Their structures were elucidated on the basis of spectroscopic and chemical methods. Compound 4 exhibited significant cytotoxic activity against human colon adenoblastoma (HT-29), and 5 showed DNA topoisomerase I and II inhibitions.

Topoisomerase I and II Inhibitory Activities and Cytotoxic Constituents from the Barks of Tilia amurnesis

  • Piao, Dong Gen;Lee, You-Jeong;Seo, Chang-Seob;Lee, Chong-Soon;Kim, Jae-Ryong;Chang, Hyun-Wook;Son, Jong-Keun
    • Natural Product Sciences
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    • v.17 no.3
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    • pp.245-249
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    • 2011
  • Eight compounds, squalene (1), friedelin (2), ${\beta}$-sitosterol (3), ${\beta}$-sitosterol-3-O-glucoside (4), ${\alpha}$-tocopherol (5), betulinic acid (6), trilinolein (7) and 1-O-(9Z,12Z-Octadecadienoyl)-3-nonadecanoyl glycerol (8), were isolated from the barks of Tilia amurensis. Their chemical structures were identified by comparing their physicochemical and spectral data with those published in the literature. These isolated compounds were examined for their inhibitory activities against topoisomerase I and II. Compound 7 showed significant inhibition of DNA topoisomerase I and II activities, with percent decreases in activity of 87 and 95%, respectively at a concentration of $100\;{\mu}M$. Compound 6 exhibited cytotoxicity against the human colon adenocarcinoma cell line (HT-29), the human breast adenocarcinoma cell line (MCF-7) and the human liver hepatoblastoma cell line (HepG-2), with $IC_{50}$ values of 20, 59 and $16\;{\mu}M$, respectively.