• 제목/요약/키워드: DNA-dependent

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DNA topoisomerase 억제제인 β-lapachone에 의한 인체 간암 및 방광암세포 증식억제에 관한 연구 (Growth Inhibition of Human Hepatoma and Bladder Carcinoma Cells by DNA Topoisomerae Inhibitor β-lapachone)

  • 최다연;이재일;정협섭;서한결;우현주;최영현
    • 생명과학회지
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    • 제15권3호
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    • pp.323-331
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    • 2005
  • 남미지역에서 자생하는 Tabebuia avellanedae라는 나무의 수피에서 동정된 quinone계 물질이며, DNA topoisomeras억제제로 알려진 $\beta-lapachone$의 항암작용에 관한 부가적인 자료를 얻기 위하여 인체 간암(HepG2) 및 방광암(T24)세포를 대상으로 조사한 결과 다음과 같은 결과를 얻게 되었다. MTT assay 및 flow cytometry 분석 등의 결과에서, $\beta-lapachone$의 처리에 따라 조사된 두 가지 암세포에서 $\beta-lapachone$처리 농도의존적으로 암세포의 심한 형태적 변형이 동반되면서 암세포의 증식이 억제되었으며, 생존율이 저하되었고 이는 apoptosis유발과 상관성이 있음을 알 수 있었다. $\beta-lapachone$처리에 의한 두 암세포의 증식억제는 종양억제 유전자 p53 및 Cdk inhibitor p21의 발현과는 큰 연관성이 없음을 RT-PCR 및 Western blot analysis를 통하여 확인하였다. 그러나 전사조절인자 Sp-1 및 세포증식 주요조절인자인 PCNA의 단백질 발현은 $\beta-lapachone$처리에 따라 매우 감소되었으며, telomere조절에 중요한 인자들의 선택적 발현 저하 현상도 관찰되었다. 이상의 결과들은 인체 암세포에서 $\beta-lapachone$의 항암작용을 이해하는 중요한 자료가 될 것이며, $\beta-lapachone$과 유사한 화학적 구조 및 성질을 가지는 항암제 후보물질들의 항암기전 비교 및 항암제 개발을 위한 기초 자료로서 응용될 것이다.

치주인대세포 및 치은섬유아세포의 DNA 합성능에 대한 b-Fibroblast growth factor의 영향 (The Effect of the Basic Fibroblast Growth Factor on Proliferation Rate of the Human Periodontal Ligament Cells and Human Gingival Fibroblasts)

  • 조영준;이재목;서조영
    • Journal of Periodontal and Implant Science
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    • 제26권2호
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    • pp.414-428
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    • 1996
  • The use of basic fibroblast growth factor which function as potent biologic mediators regulating numerous activities of wound healing has been suggested for the promotion of periodontal regeneration. The mitogenic effects of basic fibroblast growth factor on human periodontal ligament cells and human gingival fibroblasts were evaluated by determining the incorporation of 5-Bromo-2'deoxy-uridine into DNA of the cells in a dose -dependent manner. The cells which were prepared were the primary cultured gingival fibroblasts and periodontal ligament cells from human the fourth or sixth subpassages were used in the experiments. The cells which were seeded DMEM contain 10% FBS. The added concentrations of basic fibroblast growth factor were 0.1, 1, 10, 50, $l00{\eta}g/ml$ and basic fibroblast growth factor were added to the quiescent cells for 24 hours, 48 hours and 72 hours. They were labeled with $10{\mu}l/200{\mu}l$ 5Bromo-2'-deoxy-uridine for the last 6 hours of each culture. The results of the five determinants were presented as mean and S.D.. The results were as follows. : The DNA synthetic activity of human gingival fibroblasts was increased dose dependently by basic fibroblast growth factor at 24 hours, 48 hours and 72 hours. The similar mitogenic effects were at the 24 and 48 hours of basic fibroblast growth factor, but the DNA synthetic activity of human gingival fibroblasts generally decreased at 72 hours. The DNA synthetic activity of human periodontal ligament cells was increased dose dependently to $50{\eta}g/ml$ by basic fibroblast growth factor at 24, 48 and 72 hours, but the DNA synthetic activity decreased at $l00{\eta}g/ml$ of each hour. Generally the maximum mitogenic effects were at the 48 hours application of basic fibroblast growth factor. The DNA synthetic activity of human periodontal ligament cells generally decreased lower at 72 hours than at 24, 48 hours the application of basic fibroblast growth factor. In the comparison of DNA synthetic activity between human gingival fibroblasts and human periodontal ligament cells, human periodontal ligament cells had slightly higher proliferation activity than human gingival fibroblasts for a longer time at the high dosage of the basic fibroblast growth factor.In conclusion, basic fibroblast growth factor have important roles in the stimulation of DNA synthesis in human periodontal ligament cells and human gingival fibroblasts, and thus may be useful for clinical applications in periodontal regenerative procedures.

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윤폐산에 의한 폐암세포 증식억제기전에 관한 연구 (The Effects of Yunpyesan on Cell Proloferation, Apoptosis and Cell Cycle Progression of Human Lung Cancer A549 Cells)

  • 강윤경;박동일;이준혁;최영현
    • 동의생리병리학회지
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    • 제16권4호
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    • pp.745-755
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    • 2002
  • To examine the effects of Yunpyesan on the cell proliferation of A549 human lung carcinoma cell line, we performed various experiments such as dose-dependent effect of Yunpyesan on cell proliferation and viability, morphological changes, quantification of apoptotic cell death and alterations of apoptosis/cell cycle-regulatory gene products. Yunpyesan declined cell viability and proliferation in both a dose- and a time-dependent manner. The anti-proliferative effect by Yunpyesan treatment in A459 cells was associated with morphological changes such as membrane shrinking and cell rounding up. Yunpyesan Induced apoptotic cell death in a time-dependent manner, which was associated with degradation of poly-(ADP-ribose) polymerase (PARP), an apoptotic target protein, without alterations of the balance between Bcl-2 and Bax expressions. DNA flow cytometric histograms showed that population of G1 phase of the cell cycle was increased by Yunpyesan treatment in a dose-dependent manner. Western blot analysis revealed that cyclin D1 and A were reduced by Yunpyesan treatment, whereas cyclin dependent kinase (Cdk) inhibitor p27 was markedly increased in a time-dependent fashion. The level of tumor suppressor p53 proteins was also increased by Yunpyesan treatment and its increase might be linked to increase of Cdk inhibitor p27. In addition, Mdm2, negative regulator of p53, was down-regulated by Yunpyesan treatment. Since the expression of retinoblastome protein (pRB), a key regulator of G1/S progression, was reduced by Yunpyesan treatment, we supposed that phosphorylation of pRB might be also blocked. The present results indicated that Yunpyesan-induced inhibition of lung cancer cell proliferation is associated with the induction of apoptosis and the blockage of G1/S progression.

결핵균을 탐석한 말초혈액단핵구 배양상층액에 의해 유도되는 폐상피세포주에서의 NF-${\kappa}B$ 의존성 IL-8 분비기전 (NF-${\kappa}B$ Dependent IL-8 Secretion from Lung Epithelial Cells Induced by Peripheral Blood Monocytes Phagocytosing Mycobacterium Tuberculosis)

  • 박재석;지영구;최은경;김건열;이계영
    • Tuberculosis and Respiratory Diseases
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    • 제51권4호
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    • pp.315-324
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    • 2001
  • 연구배경 : IL-8은 강력한 화학주성인자로서 결핵감염 부위로 염증세포들을 동원함으로서 결핵균에 대한 숙주의 방어기전에 있어서 중요한 역할을 한다. IL-8의 유전자의 발현에 있어서 NF-${\kappa}B$가 중요한 역할을 한다. 저자들은 결핵 감염시 폐상피세포가 NF-${\kappa}B$ 의존성으로 IL-8을 분비하는지 알아보고자 하였다. 방 법 : 말초혈액단핵구에 결핵균을 감염시키고 24시간 배양 후 배양상층액(CoMTB)을 얻었다. 결핵균, CoMTB로 자극한 A549 세포주의 IL-8 분비 정도를 ELISA 방법으로 측정하였다. CoMTB로 자극한 A549 세포주의 IL-8 mRNA 의 발현 정도를 RT-PCR로, $I{\kappa}B{\alpha}$의 분해를 western blot 분석으로, NF-${\kappa}B$의 핵이동과 DNA 결합은 electrophoretic mobility shift assay(EMSA)를 이용하여, 그리고 NF-${\kappa}B$ 의존성 IL-8 유전자의 전사활성은 luciferase reporter gene assay를 이용하여 측정하였다. 결 과 : A549 세포주를 CoMTB로 24시간 자극하여 얻은 배양액의 IL-8 농도는 $46.8{\pm}4.8\;ng/ml$로 분비하여 결핵균으로 직접 자극하였을 때의 $6.8{\pm}2.9\;ng/ml$보다 높았다. CoMTB로 A549 세포주를 자극하였을 때 IL-8 mRNA의 발현이 증가하였고, $I{\kappa}B{\alpha}$의 분해가 일어났으며, NF-${\kappa}B$의 핵이동과 DNA 결합이 일어났으며, NF-${\kappa}B$ 의존성 IL-8 유전자의 전사활성이 증가하였다. 결 론 : 결핵병변에서 폐상피세포는 결핵균을 탐식한 단핵식 세포와의 상호작용에 의해 NF-${\kappa}B$ 의존성으로 IL-8을 분비한다.

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Activation of apoptotic protein in U937 cells by a component of turmeric oil

  • Lee, Yong-Kyu
    • BMB Reports
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    • 제42권2호
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    • pp.96-100
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    • 2009
  • Aromatic (ar)-turmerone from turmeric oil displays anti-tumorigenesis activity that includes inhibited cell proliferation. This study investigated ar-turmerone-mediated apoptotic protein activation in human lymphoma U937 cells. Ar-turmerone treatment inhibited U937 cell viability in a concentration-dependent fashion, with inhibition exceeding 84%. Moreover, the treatment produced nucleosomal DNA fragmentation and the percentage of sub-diploid cells increased in a concentration-dependent manner; both are hallmarks of apoptosis. The apoptotic effect of ar-turmerone was associated with the induction of Bax and p53 proteins, rather than Bcl-2 and p21. Activation of mitochondrial cytochrome c and caspase-3 demonstrated that the activation of caspases accompanied the apoptotic effect of ar-turmerone, which mediated cell death. These results suggest that the apoptotic effect of ar-turmerone on U937 cells may involve caspase-3 activation through the induction of Bax and p53, rather than Bcl-2 and p21.

전립선 암세포에서 패장 추출물의 세포고사 유도 효과 (Apoptosis-inducing Effect of Herba Patriniae Extract in the Prostate Cancer LNCaP Cells)

  • 문형철
    • 동의생리병리학회지
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    • 제18권3호
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    • pp.863-867
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    • 2004
  • Herba Patriniae(HP) has been known to exert anti-inflammation and -tumoral activity in Korea. However, its molecular mechanism of action is not understood. In this study, we found that HP extract induced apoptosis in androgen-dependent prostate cancer LNCaP cells as evidenced by DNA fragmentation. Our data demonstrated that HP extract-induced apoptotic cell death was accompanied by inhibition of NF- κB activation, lowering effects of intracellular prostate specific antigen(PSA) and androgen reoeptor(AR) expression in a time dependent manner. Taken together, HP extract may inhibit the proliferation of prostate cancer LNCaP cell associated with inhibition of NF- κB activation, PSA and AR expression and that of apoptosis.

Activation of Dihaloalkanes by Thiol-dependent Mechanisms

  • Guengerich, F. Peter
    • BMB Reports
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    • 제36권1호
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    • pp.20-27
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    • 2003
  • Dihaloalkanes constitute an important group of chemicals because of their widespread use in industry and agriculture and their potential for causing toxicity and cancer. Chronic toxic effects are considered to depend upon bioactivation, either by oxidation or thiol conjugation. Considerable evidence links genotoxicity and cancer with glutathione conjugations reactions, and some aspects of the mechanisms have been clarified with 1,2-dihaloalkanes and dihalomethanes. Recently the DNA repair protein $O^6$-alkylguanine transferase has been shown to produce cytotoxicity and genotoxicity by mans of a thiol-dependent process with similarities to the glutathione reactions.

Cell Cycle and Cancer

  • Park, Moon-Taek;Lee, Su-Jae
    • BMB Reports
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    • 제36권1호
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    • pp.60-65
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    • 2003
  • Cancer is frequently considered to be a disease of the cell cycle. As such, it is not surprising that the deregulation of the cell cycle is one of the most frequent alterations during tumor development. Cell cycle progression is a highly-ordered and tightly-regulated process that involves multiple checkpoints that assess extracellular growth signals, cell size, and DNA integrity. Cyclin-dependent kinases (CDKs) and their cyclin partners are positive regulators of accelerators that induce cell cycle progression; whereas, cyclin-dependent kinase inhibitors (CKIs) that act as brakes to stop cell cycle progression in response to regulatory signals are important negative regulators. Cancer originates from the abnormal expression of activation of positive regulators and functional suppression of negative regulators. Therefore, understanding the molecular mechanisms of the deregulation of cell cycle progression in cancer can provide important insights into how normal cells become tumorigenic, as well as how cancer treatment strategies can be designed.

Atromentin-Induced Apoptosis in Human Leukemia U937 Cells

  • Kim, Jin-Hee;Lee, Choong-Hwan
    • Journal of Microbiology and Biotechnology
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    • 제19권9호
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    • pp.946-950
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    • 2009
  • In the course of screening for apoptotic substances that induce apoptosis in human leukemia U937 cells, a fungal strain, F000487, which exhibits potent inducible activity, was selected. The active compound was purified from an ethyl acetate extract of the microorganism by Sep-pak $C_{18}$ column chromatography and HPLC, and was identified as atromentin by spectroscopic methods. This compound induced caspase-3 processing in human leukemia U937 cells. The caspase-3 and poly (ADP-ribose) polymerase (PARP) were induced by atromentin in a dose-dependent manner. Furthermore, DNA fragmentation was also induced by this compound in a dose-dependent manner. These results show that atromentin potently induces apoptosis in U937 cells and that atromentin-induced apoptosis is related to the selective activation of caspases.

Enhancement of UVB radiation-mediated apoptosis by knockdown of cytosolic NADP+-dependent isocitrate dehydrogenase in HaCaT cells

  • Lee, Su Jeong;Park, Jeen-Woo
    • BMB Reports
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    • 제47권4호
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    • pp.209-214
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    • 2014
  • Ultraviolet B (UVB) radiation induces the production of reactive oxygen species (ROS) that promote apoptotic cell death. We showed that cytosolic $NADP^+$-dependent isocitrate dehydrogenase (IDPc) plays an essential role in the control of cellular redox balance and defense against oxidative damage, by supplying NADPH for antioxidant systems. In this study, we demonstrated that knockdown of IDPc expression by RNA interference enhances UVB-induced apoptosis of immortalized human HaCaT keratinocytes. This effect manifested as DNA fragmentation, changes in cellular redox status, mitochondrial dysfunction, and modulation of apoptotic marker expression. Based on our findings, we suggest that attenuation of IDPc expression may protect skin from UVB-mediated damage, by inducing the apoptosis of UV-damaged cells.