• Asian Pacific Journal of Cancer Prevention
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• v.16 no.2
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• pp.465-469
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• 2015

Background: Orostachys japonicus A. Berger (A. Berger) is commonly used as a folk remedy for cancer therapy. However, the mechanisms of its anti-cancer activity are poorly investigated in human cancer cells. In this study, we investigated whether flavonoids extracted from Orostachys japonicus A. Berger (FEOJ) might have anticancer effects in human leukemia cells, focusing on cell death mechanisms. Materials and Methods: U937 human leukemic cancer cells were used. Results: FEOJ induced apoptosis in a dose-dependent manner in human U937 cancer cells. Flow cytometry revealed significant accumulation of cells with sub-G1 DNA content at the concentrations of $200{\mu}g/mL$ and $400{\mu}g/mL$. FEOJ-induced apoptosis was caspase-dependent through loss of mitochondrial membrane potential (MMP, ${\Delta}{\Psi}m$) in human U937 cancer cells, which might be associated with suppression of Bcl-2 and XIAP proteins. FEOJ induced the p38 MAPK signaling pathway, playing at least in part an important role in FEOJ-induced apoptosis. Conclusions: This study suggested that FEOJ may induce caspase-dependent apoptosis in human leukemic cells by regulating MMP (${\Delta}{\Psi}m$) through suppressing Bcl-2 and X-IAP. In addition, the results indicated that upstream p38 MAPK signaling regulates the apoptotic effect of FEOJ. This study provides evidence that FEOJ might have anti-cancer potential for human leukemic cells.

• Journal of Life Science
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• v.17 no.7 s.87
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• pp.896-904
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• 2007

Regulation mechanism of apoptosis has been known to be important for understanding the pathogenesis of a number of human diseases including cancers. The effects of $RRR-{\alpha}-tocopheryl$ succinate(vitamin E succinate, VES) on the cell viability, generation of ROS, expression of proteins involved in apoptosis, and growth of human chronic myelogenous leukemia K562 cells were analyzed in this study. VES treatment not only induced the generation of the ROS but also increased the levels of $NF-{\kappa}B$, COX-2, and $p21^{WAF1/CIP1}$ in K562 cells. It modulates the levels of pro-apoptotic proteins such as Bax provoking the apoptosis in K562 cells. The cleavage of PARP into 89 kDa was also increased upon VES treatment in a dosage-dependent manner. Induction of an apoptosis was evident by the increase of sub-Gl peak and cell shrinkage condensed chromatin in K562 cells treated with VES. It also resulted in an inhibition of tumor growth by 50% and prolonged survival of the Iymphoma-induced mice. This potentiation of VES obtained in vitro and in vivo may indicate the feasibility of more effective chemotherapy in chronic myelogenous leukemia.

• Journal of Physiology & Pathology in Korean Medicine
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• v.19 no.4
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• pp.913-921
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• 2005

In this study, we investigated gene expression patterns induced by Ailanthus altissima extract and compared it with Gleevec, a well-known anti-leukemia drug, in K562 chromic leukemia cells. Ailanthus altissima extract(100 ug/ml) and Gleevec(50 ug/ml) were treated to cells for 1h, 2h, 4h, and 16h and total RNA was extracted. Gene expressions were evaluated using cDMA microarray, in which 24,000 genes were spotted. Hierarchical clustering analysis showed that expression of genes included in two clusters were increased or decreased time dependently by both Ailanthus altissima extract and Gleevec. Genes included in another cluster were induced by Ailanthus altissima extract but not by Gleevec. In biological process analysis, expression of genes involved in apoptosis, growth arrest and DNA-damage were increased, but genes stimulating cell cycle were decreased. This study provides comprehensive comparison of the patterns of gene expression changes induced by Ailanthus altissima extract and Gleevec in K-562 leukemia cells.

• BMB Reports
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• v.48 no.2
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• pp.109-114
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• 2015

The COX-2/$PGE_2$ pathway has been implicated in the occurrence and progression of cancer. The underlying mechanisms facilitating the production of COX-2 and its mediator, $PGE_2$, in cancer survival remain unknown. Herein, we investigated $PGE_2$-induced COX-2 expression and signaling in HL-60 cells following menadione treatment. Treatment with $PGE_2$ activated anti-apoptotic proteins such as Bcl-2 and Bcl-xL while reducing pro-apoptotic proteins, thereby enhancing cell survival. $PGE_2$ not only induced COX-2 expression, but also prevented casapse-3, PARP, and lamin B cleavage. Silencing and inhibition of COX-2 with siRNA transfection or treatment with indomethacin led to a pronounced reduction of the extracellular levels of $PGE_2$, and restored the menadione- induced cell death. In addition, pretreatment of cells with the MEK inhibitor PD98059 and the PKA inhibitor H89 abrogated the $PGE_2$-induced expression of COX-2, suggesting involvement of the MAPK and PKA pathways. These results demonstrate that $PGE_2$ signaling acts in an autocrine manner, and specific inhibition of $PGE_2$ will provide a novel approach for the treatment of leukemia.

• Journal of Physiology & Pathology in Korean Medicine
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• v.18 no.4
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• pp.1173-1178
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• 2004

Gagamhwanglyeonhaedog-tang(GHH), a Korean genuine medicine, is a newly designed herbal drug formula based on the traditional oriental pharmacological knowledge for the purpose of treating tumorous diseases. Apoptosis is an evolutionarily conserved suicide program residing in cells. It leads to cell death through a tightly regulated process resulting in the removal of damaged or unwanted tissue. In the present study, the apoptosis inducing activities of the decocted water extract of GHH were studied. Results of the 3- [4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide assay showed that GHH had a strong cytotoxic effect on HL-60 cells. The number of live cells was less than 20% after exposure to 1㎎/㎖ GHH for 48 hr. GHH increased cytotoxicity of HL-60 cells in a dose- and time­dependent manner. Cell apoptosis by GHH was confirmed by flow cytometric analysis of the DNA-stained cells. The percentage of apoptotic cells increased to 28%, 31% and 37% 24 hr and 37%, 44% and 81% 48 hr after treatment with 0.01, 0.1 and 1㎎/㎖ GHH, respectively. Flow cytometric analysis of GHH treated HL-60 cells showed increase of hypodiploid apoptotic cells in a dose- and time- dependent manner. DNA fragmentation also occurred in apoptosis and was characterized by a ladder pattern on agarose gel. In addition, GHH (0.01 and 0.1㎎/㎖) increased the secretion of tumor necrosis factor-alpha in 24 and 48 hr. The author showed that GHH-induced apoptosis was accompanied by activation of caspase-3. These results suggest that GHH induces activation of caspase-3 and eventually leads to apoptosis.

• Natural Product Sciences
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• v.12 no.2
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• pp.109-112
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• 2006

The chloroform-soluble fraction of the vinegar treated small black soybean [Glycine max (Leguminosae)] showed antiproliferative activity against human myeloid leukemia HL-60 cells, in terms of inhibition of proliferation and induction of apoptosis. Bioassay-guided chromatography of the chloroform-soluble fraction resulted in the isolation of two isoflavonoid compounds, genistein and daidzein, as active principles. Genistein showed more potent antiproliferative effects against HL-60 cells. Treatment of HL-60 cells with genistein induced apoptosis in a dose dependent manner. Apoptosis was judged by the detection of DNA fragmentation by a flow cytometry and the degree of apoptosis was assayed by RT-PCR.

• Journal of Microbiology and Biotechnology
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• v.15 no.3
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• pp.532-536
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• 2005

In the course of our screening for small molecules to inhibit apoptosis of U937 human leukemia cells induced by etoposide ($10\;{\mu}g/ml$), Penicillium sp. F020150 with potent inhibitory activity was selected. The active compound was purified from ethyl acetate extract of the microorganism by Sephadex LH-20 column chromatography and HPLC, and was identified as gentisyl alcohol (2,5-dihydroxybenzyl alcohol) by spectroscopic methods. The compound inhibited caspase-3 induction with $IC_{50}$ value of $3.0\;{\mu}g/ml$ after 8 h of etoposide treatment. The expression levels of caspase-3 and PARP were dose-dependently inhibited by the compound, suggesting that gentisyl alcohol inhibits etoposide-induced apoptosis via downregulation of caspases.

• Journal of Physiology & Pathology in Korean Medicine
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• v.16 no.6
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• pp.1223-1229
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• 2002

The purpose of this research was to investigate the effect of Cheongsimondam-tang(CSODT) on the activity of immune cell and anti-carcinogenic effect of mouse leukemia cell. The addition of CSODT(1 ㎍/ml) enhanced the proliferation of cultured-splenocytes and thymocytes. And also administration of CSODT(500 ㎍/kg) accelerated subpopulation of splenic and thymic T lymphocytes especially CD4/sup +/-T/sub H/ cells in BALB/c mice. CSODT treatment decreased cell proliferation and increased apoptotic cell death of cultured-L1210 leukemia cells, and induced apoptosis in addition to decreased mitochondrial transmembrane potential (ΔΨm) of transplanted-L1210 cells in vivo. These results suggest that CSODT have a cellular immuno-regulatory effect and anti-cancer property action.

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.90.2-90.2
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• 2003

In a continuous effort to develop novel anticancer agents we newly synthesized and evaluated the antitumor activity of nucleoside analogues. One analogue, 4-[2-Chlor-6-(3-iodo-benzylamino)-purin-9-yl]-2,3-dihydroxy-cyclopentanecarboxylic acid methylamide (LJ-331), has been shown to exert a potent inhibition of human cancer cell growth in vitro including human lung (A549), stomach (SNU-638) and leukemia (HL-60) cancer cells. Following mechanism of action study revealed that LJ-331 induces cell cycle arrest at the G$_1$ phase in HL-60 cells and evokes apoptotic phenomena such as an increase in DNA ladder intensity and chromatin condensation by a dose-and time-dependent manner. (omitted)

• Radiation Oncology Journal
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• v.18 no.1
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• pp.51-58
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• 2000

Purpose :The effect of PTK inhibitors (herbimycin A and genistein) on the induction of radiation-induced apoptosis in Ph-positive KS62 leukemia cell line was investigated. Materials and Methods :K562 cells in exponential growth phase were irradiated with a linear accelerator at room temperature. For 6 MV X-ray irradiation and drug treatment, cultures were initiated at 2×106 cells/mL. The cells were irradiated with 10 Gy. Stock solutions of herbimycin A and genistein were prepared in dimethyl sulphoxide (DMSO). After incubation at 37$^{\circ}C$ for 0$\~$48 h, the extent of apoptosis was determined using agarose gel electrophoresis and TUNEL assay. The progression of cells through the cell cycle after irradiation and drug treatment was also determined with flow cytometry. Western blot analysis was used to monitor bel-2, bel-X$_{L}$ and bax protein levels. Results :Treatment with 10 Gy X-irradiation did not result in the induction of apoptosis. The HMA alone (500 nM) also failed to induce apoptosis. By contrast, incubation of K562 cells with HMA after irradiation resulted in a substantial induction of nuclear condensation and fragmentation by agarose gel electro-phoresis and TUNEL assay. Genistein failed to enhance the ability of X-irradiation to induce DNA fragmentation. Enhancement of apoptosis by HMA was not attributable to downregulation of the bel-2 or bel-X$_{L}$ anti-apoptotic proteins. When the cells were irradiated and maintained with HMA, the percentage of cells in G2/M phase decreased to 30$\~$40$\%$ at 48 h. On the other hand, cells exposed to 10 Gy X-irradiation alone or maintained with genistein did not show marked cell cycle redistribution. Conclusion : We have shown that nanomolar concentrations of the PTK inhibitor HMA synergize with X-irradiation in inducing the apoptosis in Ph (+) K562 leukemia cell line. While, genistein, a PTK inhibitor which is not selective for p210$^{bcr/abl}$ failed to enhance the radiation induced apoptosis in KS62 cells. It is unlikely that the ability of HMA to enhance apoptosis in K562 cells is attributable to bel-2 family. It is plausible that the relationship between cell cycle delays and cell death is essential for drug development based on molecular targeting designed to modify radiation-induced apoptosis.