• BMB Reports
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• v.36 no.4
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• pp.387-389
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• 2003

The young developing leaves of willow (Salix safsaf, Salicaceae) trees have antileukemic activity. After a 24-h incubation in vitro, the crude water extracts of the leaves killed a majority of the blasts of acute myeloid leukemia (AML, 73.8%).

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.166.3-167
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• 2003

Helenalin, a cell-permeable pseudoguainolide sesquiterpene lactone, is a potent anti-inflammatory agent that inhibits $NF-{\kappa}B$ DNA binding activity by selectively alkylating the p65 subunit of $NF-{\kappa}B$. Transcription factors such as $NF-{\kappa}B$ provide powerful target of drugs to use in the treatment of cancer. Human promyelocytic leukemia HL-60 cells are differentiated into monocytic or granulocytic lineage when treated with 1,25-dihydroxyvitamin $D_3{\;}[1,25-(OH)_2D_3]$ or all-trans-retinoic acid (ATRA), respectively. (omitted)

• Journal of Photoscience
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• v.9 no.2
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• pp.509-511
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• 2002

In this study, we investigated apoptotic cell death induced by photodynamic therapy using 5-aminolaevulinic acid (ALA-PDT) in human promyelocytic leukemia cells (HL-60). ALA-PDT induced apoptosis in HL-60 cells as confirmed by DNA agarose gel electrophoresis and nuclear staining with Hoechst 33342. The apoptotic cell death was inhibited by addition of broad-spectrum caspase inhibitor Z-Asp-CH$_2$-DCB, indicating that the apoptotic cell death was induced in a caspase-dependent manner. Actually, western blotting analysis revealed that caspase-3 was processed as early as 1.5 h after ALA-PDT. Cytoplasmic cytochrome c released from mitochondria was detected by western blotting. However, inhibitor of caspase-9, a cysteine protease located in the downstream of cytochrome c release, was not able to reduce the apoptotic cell death. Therefore, the mitochondrial apoptotic pathway was not involved in the ALA-PDT-induced apoptosis. On the other hand, it was found that ALA-PDT-induced apoptosis was clearly inhibited by pretreatment of caspase-8 inhibitor. These data suggest that caspase-8-mediated apoptotic pathway is important in ALA-PDT-induced cell death.

• Molecules and Cells
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• v.44 no.7
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• pp.444-457
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• 2021

Although the mechanism of chronic myeloid leukemia (CML) initiation through BCR/ABL oncogene has been well characterized, CML cell differentiation into erythroid lineage cells remains poorly understood. Using CRISPR-Cas9 screening, we identify Chromobox 8 (CBX8) as a negative regulator of K562 cell differentiation into erythrocytes. CBX8 is degraded via proteasomal pathway during K562 cell differentiation, which activates the expression of erythroid differentiation-related genes that are repressed by CBX8 in the complex of PRC1. During the differentiation process, the serine/threonine-protein kinase PIM1 phosphorylates serine 196 on CBX8, which contributes to CBX8 reduction. When CD235A expression levels are analyzed, the result reveals that the knockdown of PIM1 inhibits K562 cell differentiation. We also identify TRIM28 as another interaction partner of CBX8 by proteomic analysis. Intriguingly, TRIM28 maintains protein stability of CBX8 and TRIM28 loss significantly induces proteasomal degradation of CBX8, resulting in an acceleration of erythroid differentiation. Here, we demonstrate the involvement of the CBX8-TRIM28 axis during CML cell differentiation, suggesting that CBX8 and TRIM28 are promising novel targets for CML research.

• Journal of Nutrition and Health
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• v.31 no.4
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• pp.799-808
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• 1998

To investigate the antitumor activity of mugwort (Artemisia princeps Pampan), petroleum ether extract of mugwork was partially purified by a silica gel chromatography. Among several fractions, the fraction which was obtained under the elution with acetone, showed potent cytotoxicity against mouse leukemia cell line(Ll210), human colon cancer cell line (HCT-48) and human hepatoma cell line (Hep G2) , but was less effective with normal cell line(mouse embryo cell). Acetone fraction appeared to be glycolipid by Benedict test and the major fatty acids of the lipid were C16 ; 0 , C 18: 3by GC/MS analysis.

• Journal of Life Science
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• v.10 no.1
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• pp.57-63
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• 2000

${\beta}$-catenin, which plays a critical role in both the cytoskeleton and in transcriptional regulation in variousadherent cell types, undergoes degradation during adherent cell apoptosis. Although ${\beta}$-catenin has been reported to be present in Jurkat T-acute lymphoblastic leukemia cells, the regulation of ${\beta}$-catenin in hematologic malignancies have not been examined. The data presented here demonstrate that treatment of the T cell leukemia Jurkat iwht the apoptosis inducer anti-Fas induced proteolytic cleavage of ${\beta}$-catenin. ${\beta}$-catenin was cleaved at both the N- and C-terminus after anti-Fas treatment. Cleavage of intact ${\beta}$-catenin was completely inhibited by caspase selective protease inhibitors. These data demonstrate that ${\beta}$ -catenin proteolysis is triggered by the cross-linking of the Fas receptor on Jurkat cells and subsequent activation of caspase protease. There was a clear accumulatio of the large proteolytic fragment in Jurkat cells treated with lactacystin of ALLM. These are potent inhibitors of proteasome and calpain. these results suggest that both the proteasome and clapain may recognize the large ${\beta}$-catenin fragment as a substrate fot further degradation and that these pathewasy may act downstream of scapase in response to Fas receptor activation. Therefore, we suggest that ${\beta}$-catenin may play a role in promoting Jurkat survival.

• Journal of Yeungnam Medical Science
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• v.28 no.2
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• pp.187-191
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• 2011

Adult T-cell leukemia/lymphoma (ATLL) is a malignancy of mature T-cells caused by the human T-cell lymphotrophic virus type I (HTLV-D. HTLV-I is endemic in some areas in Japan, the Caribbean basin, and Africa but has low prevalence in South Korea. Patients with ATLL are susceptible to opportunistic infections such as cytomegalovirus (CMV) infection, but CMV infection in chronic ATLL is uncommon. Reported herein is a case involving a 44-year-old woman with chronic ATLL who presented the symptoms of fever and diarrhea. She was suspected to have acute-type ATLL but was later diagnosed with CMV colitis.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.12
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• pp.7719-7724
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• 2013

Background: Overexpression of survivin, a known inhibitor of apoptosis, is associated with tumor progression and drug resistance in numerous malignancies, including leukemias. The aim of this study was to investigate the effect of a specific survivin small interference RNA (siRNA) on proliferation and the sensitivity of HL-60 acute myeloid leukemia (AML) cells to the chemotherapeutic drug etoposide. Materials and Methods: The cells were transfected with siRNAs using Lipofectamine $^{TM}2000$ transfection reagent. Relative survivin mRNA and protein levels were measured by quantitative real-time PCR and Western blotting, respectively. Trypan blue exclusion assays were performed to monitor tumor cell proliferation after siRNA transfection. The cytotoxic effects of etoposide and survivin siRNA, alone and in combination, on leukemic cells were determined using MTT assay. Apoptosis was assessed by ELISA cell death assay. Results: Survivin siRNA markedly reduced both mRNA and protein expression levels in a time-dependent manner, leading to distinct inhibition of cell proliferation and increased spontaneous apoptosis. Surprisingly, survivin siRNA synergistically increased the cell toxic effects of etoposide. Moreover, survivin down-regulation significantly enhanced its induction of apoptosis. Conclusions: Our study suggests that down-regulation of survivin by siRNA can trigger apoptosis and overcome drug resistance of leukemia cells. Therefore, survivin siRNA may be an effective adjuvant in AML chemotherapy.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.3
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• pp.1721-1724
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• 2013

Objective: To investigate the effect of epirubicin on soluble CD25 (sCD25) secretion by CD4+CD25+ regulatory T (Treg) cells isolated from diffuse large B-cell lymphoma (DLBCL) patients. Methods: Treg cells were isolated from the peripheral blood mononuclear cells isolated from the newly diagnosed DBLCL patients. The concentration of sCD25 in the supernatant was determined with a commercial sCD25 (IL-2R) enzyme-linked immunosorbent assay (ELISA) kit. The fluorescence intensity of CD25 was detected by flow cytometry. Results: Cell survival rate was significantly decreased along with the increase of epirubicin concentration after treatment for 24 h. There was also a significant difference in the concentration of sCD25 between the epirubicin group and the control group (P<0.01). A positive correlation between the Treg cells survival rate and the concentration of sCD25 was detected (r=0.993, P<0.01). When equal numbers of CD4+CD25+ Treg cells of the epirubicin group and the control group were cultured for another 24 h without epirubicin the CD25 fluorescence intensity on the surface of Treg cells was obviously higher in the epirubicin group than that in the control group (P<0.01), while the sCD25 concentration in the supernatant in the epirubicin group was significantly lower than that in the control group (P<0.05). Conclusion: Epirubicin may improve the body's immune functions by inhibiting the sCD25 secretion by Treg cells in DLBCL patients.

• Journal of Microbiology
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• v.44 no.4
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• pp.447-452
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• 2006

The murine ecotropic retroviral receptor has been demonstrated to function as a mouse cationic amino acid transporter 1(mCAT1), and is comprised of multiple membranespanning domains. Feral mouse (Mus dunni) cells are not susceptible to infection by the ecotropic Moloney murine leukemia virus (MoMLV), although they can be infected by other ecotropic murine leukemia viruses, including Friend MLV and Rauscher MLV. The relative inability of MoMLV to replicate in M. dunni cells has been attributed to two amino acids $(V_{214}\;and\;G_{236})$ located within the third extracellular loop of the M. dunni CAT1 receptor (dCAT1). Via the exchange of the third extracellular loop of the mCAT1 cDNA encoding receptor from the permissive mouse and the corresponding portion of cDNA encoding for the nonpermissive M. dunni receptor, we have identified the most critical amino acid residue, which is a glycine located at position 236 within the third extracellular loop of dCAT1. We also attempted to determine the role of the third extracellular loop of the M. dunni CAT1 receptor with regard to the formation of the syncytium. The relationship between dCAT1 and virus-induced syncytia was suggested initially by our previous identification of two MLV isolates (S82F in Moloney and S84A in Friend MLV), both of which are uniquely cytopathic in M. dunni cells. In an attempt to determine the relationship existing between dCAT1 and the virally-induced syncytia, we infected 293-dCAT1 or chimeric dCAT1 cells with the S82F pseudotype virus. The S82F pseudotype virus did not induce the formation of syncytia, but did show increased susceptibility to 293 cells expressing dCATl. The results of our study indicate that S82F-induced syncytium formation may be the result of cell-cell fusion, but not virus-cell fusion.