• 생명과학회지
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• 제17권4호
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• pp.552-560
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• 2007

본 연구에서는 인체백혈병세포 U937에서 HDAC 저해제에 의한 증식억제, 세포주기 교란 및 apoptosis 유도에 미치는 Bcl-2 유전자의 영향에 관하여 조사하였다. 이를 위하여 U937/vector 및 U937/Bcl-2 세포주를 대상으로 대표적인 HDAC 저해제인 TSA 및 Na-B 처리에 의한 세포 증식 및 생존율에 미치는 영향을 조사한 결과, TSA에 의한 U937 세포의 증식억제 및 생존율의 감소는 Bcl-2의 과발현에 의하여 차단되는 효과를 보였으나, Na-B는 U937/vector 및 U937/Bcl-2세포사이에 큰 변화를 보이지는 않았다. 세포주기 교란효과에서 Na-B는 TSA에 비하여 유의적인 차이를 보이지 못하였으며, 이는 TSA에 의한 apoptosis가 U937/Bcl-2 세포에서는 억제되었으나, Na-B에 의한 apoptosis는 Bcl-2의 과발현에 의하여 차단되지 못한 것과 연관성이 있는 결과였다. 또한 TSA에 의한 apoptosis 유발의 Bcl-2에 의한 차단 효과는 TSA에 의하여 활성화된 caspase의 활성 억제, Bcl-2 발현 자체의 완화 등 apoptosis 조절 인자들의 발현 및 활성 변화에 기인 된 것임을 알 수 있었다.

• 한국해양바이오학회지
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• 제1권2호
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• pp.63-70
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• 2006

본 연구에서는 U937 인체 백혈병 세포의 증식에 미치는 PTX-2의 영향을 조사한 결과, PTX-2의 처리에 따라 U937 세포는 처리 농도 및 처리 시간 의존적으로 심한 형태적 변형과 함께 증식이 억제되었다. 이러한 PTX-2 처리에 의한 U937 세포의 증식억제는 apoptosis 유발과 관련이 있었으며, 이를 DAPI staining에 의한 apoptotic body 형성, flow cytometry를 이용한 sub-G1 세포 빈도의 정량적 분석을 통하여 확인하였다. 이러한 PTX-2 처리에 의한 U937 세포의 apoptosis 유발은 Bcl-2 family에 속하는 anti-apoptotic 인자인 Bcl-$X_L$의 발현 감소 및 IAPs family에 속하는 유전자들의 선택적 발현 감소와 연관성이 있음을 알 수 있었다. 이상의 결과들은 인체 암세포에서 PTX-2의 항암작용을 이해하는데 중요한 자료가 될 것이고 나아가 PTX-2을 포함한 그와 유사한 항암제 후보물질들의 연구에 있어서 기초 자료로서 사용될 수 있을 것으로 생각된다.

• 생약학회지
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• 제33권1호통권128호
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• pp.29-34
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• 2002

Albizzia julibrissin belonging to the family Leguminosae has been used for the treatment of contusion, sore throat, amnesia, and insomnia in Oriental traditional medicine. The water extract of A. julibrissin induced apoptosis in Jurkat T-acute lymphoblastic leukemia (ALL) cells as measured by cell morphology. The capability of this herb medicine to induce apoptosis was associated with proteolytic cleavage of specific target protein such as beta-catenin protein suggesting the possible involvement of caspases. The purpose of the present study is also to investigate the effect of A. julibrissin on cell cycle progression. Our results showed that GI checkpoint related gene products (cyclin D1, cyclin dependent kinase 4, retinoblastoma, E2F1) were decreased in their protein levels in a dose-dependent manners after treatment of the extract. These results indicate that the increase of apoptotic cell death by A. julibrissin may be due to the inhibition of cell cycle progression in wild type p53-lacking Jurkat cells.

• 약학회지
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• 제45권6호
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• pp.730-738
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• 2001

Apoptosis is a morphologically and biochemically distinct form of cell death that occurs in many different cell types in a wide variety of organisms. Ajbizzia julibrissin belonging the family Leguminosae has been used for the treatment of contusion, sore throat, amnesia, and insomnia in oriental traditional medicine. This study investigates whether the water extract off julibrissin induce apoptotic cell death in Jurkat T-acute lymphoblastic leukemia (ALL) cells. Jurkat cells were increased inhibitions of cell viability in a concentration-dependent manner by A julibrissin. This herbal medicine also caused apoptosis as measured by cell morphology and DNA fragmentation. The capability oft julibrissin to induce apoptosis was associated with proteolytic cleavage of specific target protein such as poly (ADP-ribose) polymerase (PARP) protein suggesting the possible involvement of caspases. Our result skewed that Bcl-2 and Bax protein levels were not changed in all A julibrissin-treated groups compared to control group. These results suggest that A julibrissin-mediated apoptosis is independent with Bcl-2 related signaling pathway in this cells.

• 약학회지
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• 제37권1호
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• pp.89-94
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• 1993

In order to find out a proper connecting bridge between 5-fluorouracil(5-FU) and a macromolecule such as a polypeptide, potentially hydrolytic N$^{1}$-derivartives of 5-FU have been systhesized and evaluated for their biological activity. When tested with in vitro leukemic L$_{1210}$ cells all the obtained derivartives exhibited slightly higher antitumor activity than the parent 5FU. Among them the N$^{1}$ -carbamoyl analogue 2 and N$^{1}$-acetamido analogue 6b showed 50% inhibition of the L$_{1210}$ cell growth at the concentrations of 5.01$\times$10$^{-8}$M and 1.03$\times$10$^{-7}$M, respectively. When tested against sarcoma 180 tumor cells inoculated into mice, the compounds 2 and 6b exhibited, respectively, 62% and 54% inhibition of the solid tumor growth at the 5-time doses of 100 mg/kg/day. Both compounds, N$^{1}$-carbamoyl analogue 2 and N$^{1}$-acetamido analogue 6b, realeased the parent 5-FU when incubated in the L$_{1210}$ cell cultural media for 5 hrs.

• Molecules and Cells
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• 제41권5호
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• pp.444-453
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• 2018

Aberrations in histone modifications are being studied in mixed-lineage leukemia (MLL)-AF9-driven acute myeloid leukemia (AML). In this study, we focused on the regulation of the differentiation of the MLL-AF9 type AML cell line THP-1. We observed that, upon phorbol 12-myristate 13-acetate (PMA) treatment, THP-1 cells differentiated into monocytes by down-regulating Aurora kinase A (AURKA), resulting in a reduction in H3S10 phosphorylation. We revealed that the AURKA inhibitor alisertib accelerates the expression of the H3K27 demethylase KDM6B, thereby dissociating AURKA and YY1 from the KDM6B promoter region. Using Flow cytometry, we found that alisertib induces THP-1 differentiation into monocytes. Furthermore, we found that treatment with the KDM6B inhibitor GSK-J4 perturbed the PMA-mediated differentiation of THP-1 cells. Thus, we discovered the mechanism of AURKA-KDM6B signaling that controls the differentiation of THP-1 cells, which has implications for biotherapy for leukemia.

• Natural Product Sciences
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• 제13권2호
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• pp.169-173
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• 2007

Luteolin is a major flavonoid of Lonicera japonica and has anti-inflammatory effect. The activation of proteinase-activated receptor (PAR)-2 and -4 by trypsin appears to play a role in inflammation, In the present study, we examined the inhibitory effects of luteolin on activation of trypsin-induced human leukemic mast cells (HMC-1). HMC-1 cells were stimulated with trypsin, PAR-2 and PAR-4 agonist, in the presence or absence of luteolin. The level of TNF-${\alpha}$ secretion was measured by enzyme-linked immunosorbent assay (ELISA). The expression of tryptase and phosphorylated-extracellular signal-regulated kinase (ERK) were assessed by Westem blot analysis. Moreover, trypsin activity was measured by the substrate Bz-DL-Arg-p-nitroanilide (BAPNA). TNF-${\alpha}$ secretion and Tryptase expression in trypsin-stimulated HMC-1 cells were markedly inhibited by pretreatment of luteolin. Furthermore, the pretreatment of luteolin resulted in the reduction of ERK phosphorylation and trypsin activity. These results suggest that luteolin might has the inhibitory effects on the PAR-2 and -4-dependent inflammation.

• IMMUNE NETWORK
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• 제6권4호
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• pp.179-184
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• 2006

Background: Identification of antigen-specific T cells has yielded valuable information on pathologic process and the disease state. Assays for quantification of inflammatory cytokines or lytic-granule molecules have been generally used to evaluate antigen specific T cell response, however their applicability have been hampered due to the limited source of autologous antigen-presenting target cells (APC). Methods: K562, a leukemic cell line deficient of human leukocyte antigen (HLA), was transfected with a gene encoding HLA-A*02 (K562/ A*02) and its function as stimulator cells in inducing activation of HLA-matched T cells was evaluated by IFN-${\gamma}$ enzyme linked immunospot (ELISPOT) assay. Results: The stable transfectant K562/ A*02 pulsed with HLA- A*02 restricted peptide could specifically induce IFN-${\gamma}$ secretion by CD8+ T cells compared to no detectable secretion by CD4+ T cells. However, CD56+ NK cells secreted IFN-${\gamma}$ in both K562/ A*02 with peptide and without peptide. The number of IFN-${\gamma}$ secreted CD8+ T cells was increased according to the ratio of T cells to K562 and peptide concentration. Formalin-fixed K562/ A*02 showed similar antigen presenting function to live K562/ A*02. Moreover, K562/ A*02 could present antigenicpeptide to not only A*0201 restricted CD8+ T cells but also CD8+ T cells from A*0206 donor. Conclusion: These results suggest that K562/ A*02 could be generally used as target having specificity and negligible background for measuring CD8+ T cell responses and selective use of K562 with responsder matched HLA molecules on its surface as APC may circumvent the limitation of providing HLA-matched autologous target cells.

• 한국해양바이오학회지
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• 제1권2호
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• pp.76-83
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• 2006

본 연구에서는 다양한 인체암세포의 증식에 미치는 등불가사리 메탄올 추출물(MEGF)의 영향을 조사하였다. MEGF는 처리 농도의존적으로 암세포의 형태적변이 및 증식억제가 효과를 보여주었으며, 특히 백혈병세포에서 가장 높은 감수성을 보여주었다. 따라서 백혈병세포의 증식억제 효과가 apoptosis 유발과 연관성이 있는지를 flow cytometry 분석 및 DAPI staining 법으로 조사한 결과, MEGF 처리에 의한 백혈병세포의 증식억제는 세포주기 교란과 무관한 apoptosis 유발에 의한 것임을 sub-G1기 세포의 빈도 증가 및 apoptotic body 형성의 증가 등으로 확인하였다. 또한 MEGF 처리에 의한 백혈병세포의 증식억제 및 apoptosis 유발은 p53 비의존적인 p21의 발현 증가 및 Fas/FasL system의 발현 증가와 연관성이 있음을 알 수 있었다. 이상의 결과들은 인체 암세포, 특히 백혈병세포에서 MEGF의 항암작용을 이해하는데 중요한 자료가 될 것이고 나아가 MEGF 내 함유된 생리활성 물질의 분리 및 항암적용 연구를 위한 중요한 기초 자료로 활용될 것이다.

• BMB Reports
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• 제38권4호
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• pp.391-398
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• 2005

3-hydrogenwadaphnin (3-HK) is a new daphnane-type diterpene ester isolated from Dendrostellera lessertii with strong anti-tumoral activity in animal models and in cultures. Here, prolonged effects of this new agent on proliferation and viability of several different cancerous cell lines were evaluated. Using [$^3H$]thymidine incorporation, it was found that the drug inhibited cell proliferation and induced G1/S cell cycle arrest in leukemic cells 24 h after a single dose treatment. The cell viability of Jurkat cells was also decreased by almost 10%, 31% and 40% after a single dose treatment (7.5 nM) at 24, 48 and 72 h, respectively. The drug-treated cells were stained with acridine orange/ethidium bromide to document the chromatin condensation and DNA fragmentation. These observations were further confirmed by detection of DNA laddering pattern in the agarose gel electrophoresis of the extracted DNA from the treated cells. Treatment of K562 cells with the drug at 7.5, 15 and 30 nM caused apoptosis in 25%, 45% and 65% of the cells, respectively. Exogenous addition of $25-50\;{\mu}M$ guanosine and/or deoxyguanosine to the cell culture of the drug-treated cells restored DNA synthesis, released cell arrest at G1/S checkpoint and decreased the apoptotic cell death caused by the drug. These observations were not made using adenosine. However, the drug effects on K562 cells were potentiated by hypoxanthine. Based on these observations, perturbation of GTP metabolism is considered as one of the main reasons for apoptotic cell death by 3-HK.