• 동의생리병리학회지
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• 제19권2호
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• pp.452-458
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• 2005

Cordyceps militaris is a medicinal fungus, which has been used for patient suffering from cancer in Oriental medicine. It was reported previously that C. militaris extracts are capable of inhibiting tumor growth, however, the anti-poliferative effects of human cancer cells have not been poorly understood. In this study, to elucidate the growth inhibitory mechanisms of human cancer cells by treatment of aqueous extract of C. militaris (AECM) we investigated the anti-proliferative effects of AECM in human leukemia U937 cell line. AECM treatment inhibited the growth of U937 cells and induced the apoptotic cell death in a concentration-dependent manner, which was associated with morphological changes. We observed the up-regulation of cyclin-dependent kinase (Cdk) inhibitor p21(WAF1/CIP1) by p53-independent manner and activation of caspase-3 in AECM-treated U937 cells, however, the activity of caspase-9 was remained unchanged. Additionally, AECM treatment caused a dose-dependent inhibition of the expression of telomere regulatory gene products such as human telomere reverse transcriptase (hTERT) and telomerase-associated protein-1 (TEP-1). Taken together, these findings suggest that AECM-induced inhibition of human leukemic cell proliferation is associated with the induction of apoptotic cell death via modulation of several major growth regulatory gene products, and C. militaris may have therapeutic potential in human lung cancer.

• Biomolecules & Therapeutics
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• 제15권3호
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• pp.145-149
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• 2007

We have previously shown that 2,4,3',5'-tetramethoxystilbene (TMS), a synthetic trans-stilbene analogue acting as a potent inhibitor of human cytochrome P450 1B1, induces apoptotic cell death in human cancer cells. In the present studies, we report the mechanisms of apoptotic cell death by TMS in human promyelocytic leukemic HL-60 cells. We found that treatment of HL-60 cells with TMS suppressed the cell growth in a concentration-dependent manner with $IC_{50}$ value of about 0.8 ${\mu}M$. Immunoblot experiments revealed that DMHS-induced apoptosis was associated with cleavage of poly (ADP-ribose) polymerase. The release of cytochrome c from mitochondria into the cytosol was significantly increased in response to TMS. TMS caused activation of caspase-3 in a concentration-dependent manner and TMS-mediated caspase-3 activation was partially prevented by the caspase inhibitor, zVAD-fmk. Interestingly, we found that the cytotoxic effect of anticancer drugs such as paclitaxel, docetaxel, or etoposide was enhanced in the presence of TMS. Simultaneous treatment with TCDD also significantly increased cytotoxic effects of TMS alone or TMS and anti-cancer agents. Taken together, our present results indicated that TMS leads to apoptotic cell death in HL-60 cells through activation of caspase-3 activity and release of cytochrome c into cytosol. The ability of TMS to increase cytotoxic effect of anticancer drugs may contribute to its usefulness for cancer chemotherapy.

• 동의생리병리학회지
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• 제19권6호
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• pp.1636-1639
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• 2005

To develop novel anti-leukemic medicine, we have prepared a Korean traditional medicine, named Hang-baek-Tang, which is composed of 8 kinds of anti-leukemic medicinal plants. The water extracts was examined anti-leukemic activity using the human leukemia cell line, HL-60 cells. HL-60 cells showed the growth inhibition and several apoptotic features, including DNA ladders, morphological changes, by treatment of the cells with Hang-Daek-Tang. We have observed that Hang-baek-Tang induced the activation of caspase-3, caspase-8 and caspase-9. Further molecular analysis demonstrated that Hang-baek-Tang induced cleavage of PARP and increase of hypodiploid (Sub-G1) population in flow cytometric analysis. These results indicate that Hang-baek-Tang has been considered to exert anti-leukemic activity through the procaspase-3 activation pathway.

• 대한약학회:학술대회논문집
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• 대한약학회 2001년도 Proceedings of International Convention of the Pharmaceutical Society of Korea
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• pp.205.1-205.1
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• 2001

• 대한약학회:학술대회논문집
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• 대한약학회 2001년도 Proceedings of the Pharmaceutical Society of Korea
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• pp.170.2-170.2
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• 2001

• Nutrition Research and Practice
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• 제8권2호
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• pp.132-137
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• 2014

BACKGROUND/OBJECTIVES: In this study, the apoptogenic activity and mechanisms of cell death induced by hexane extract of aged black garlic (HEABG) were investigated in human leukemic U937 cells. MATERIALS/METHODS: Cytotoxicity was evaluated by MTT (3-(4, 5-dimethyl-thiazol-2-yl)-2, 5-diphenyl tetrazoliumbromide) assay. Apoptosis was detected using 4,6-diamidino-2-phenyllindile (DAPI) staining, agarose gel electrophoresis and flow cytometry. The protein levels were determined by Western blot analysis. Caspase activity was measured using a colorimetric assay. RESULTS: Exposure to HEABG was found to result in a concentration- and time-dependent growth inhibition by induction of apoptosis, which was associated with an up-regulation of death receptor 4 and Fas legend, and an increase in the ratio of Bax/Bcl-2 protein expression. Apoptosis-inducing concentrations of HEABG induced the activation of caspase-9, an initiator caspase of the mitochodrial mediated intrinsic pathway, and caspase-3, accompanied by proteolytic degradation of poly(ADP-ribose)-polymerase. HEABG also induced apoptosis via a death receptor mediated extrinsic pathway by caspase-8 activation, resulting in the truncation of Bid, and suggesting the existence of cross-talk between the extrinsic and intrinsic pathways. However, pre-treatment of U937 cells with the caspase-3 inhibitor, z-DEVD-fmk, significantly blocked the HEABG-induced apoptosis of these cells, and increased the survival rate of HEABG-treated cells, confirming that HEABG-induced apoptosis is mediated through activation of caspase cascade. CONCLUSIONS: Based on the overall results, we suggest that HEABG reduces leukemic cell growth by inducing caspase-dependent apoptosis through both intrinsic and extrinsic pathways, implying its potential therapeutic value in the treatment of leukemia.

• Asian Pacific Journal of Cancer Prevention
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• 제16권2호
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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.

• 생명과학회지
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• 제16권4호
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• pp.589-597
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• 2006

본 연구에서는 T24 인체방광암 및 U937 백혈병 세포의 증식에 미치는 genistein의 영향을 조사 하였다. Genistein이 처리된 T24 및 U937 세포는 처리 농도 의존적으로 세포의 증식이 현저히 감소되었으며 심한 형태적 변형이 동반되었으나, U937 세포에서 보다 높은 감수성을 보였다. 이러한 T24 및 U937 세포의 증식억제 및 형태 변형은 G2/M기의 세포주기 억제 및 apoptosis 유발과 연관성이 있음을 flow cytometry를 이용한 세포주기의 분석을 통하여 확인하였다. T24 세포에서 genistein에 의한 G2/M arrest는 cyclin A, cyclin B1 및 Cdc25C 등의 단백질 발현 감소와 연관성이 있었으나, 종양억제 유전자 p53 및 Cdk inhibitor p21의 발현에는 큰 변화가 없었다. U937 세포에서 genistein에 의한 G2/M arrest는 cyclin B1 및 p53 비의존적인 p21의 발현 증가와 연관성이 있었다. 이상의 결과들은 현재까지 거의 연구가 진행된 바 없는 인체방광암 및 백혈병 세포에서 genistein의 항암작용을 이해하는데 중요한 자료가 될 것이고 나아가 genistein을 포함한 그와 유사한 항암제 후보물질들의 연구에 있어서 기초 자료로서 사용될 수 있을 것으로 생각된다.

• Archives of Pharmacal Research
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• 제25권4호
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• pp.421-427
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• 2002

For probing the importance of planarity of imidazolidinone motif of 4-phenyl-1-(N-acylindoline-5-sulfonyl)imidazolidinones 1 for their cytotoxicity, 4-phenyl-1-(N-acylindoline-5-sulfonyl)[1,2,5]thiadiazolidine-1,1-dioxides 2 were prepared and their cytotoxicity were measured against human lung carcinoma (A549), human colon carcinoma (COLO205), human ovarian cancer (SK-OV-3), human leukemic cancer (K562), and murine colon adenocarcinoma (Colon26) cell lines in vitro. Although only carbonyl moiety of imidazolidinone ring was replaced with sulfonyl group, compounds 2 do not show any activity against all five cancer cell lines unlike 1. Therefore the planarity of imidazolidinone ring of 1 should be an important factor for their cytotoxic activity.

• 동의생리병리학회지
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• 제17권3호
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• pp.629-632
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• 2003

Scutellaria barbata has been used as a traditional Chinese Herb for treating liver, lung and rectal tumors. In the present study, cytotoxic effect of Scutellaria barbata MC fradtion was investigated and it was found to inhibit proliferation of human leukemic U937 cells with an IC50 of approximately 10 μg/ml in a dose-dependent manner. We also demonstrated that Scutellaria barbata MC fraction caused apoptosis in U937 cells. In the flow cytometric assay, the MC fraction-treated U937 cells showed an increase in hypo-diplold Sub G1 DNA contents. DNA fragmentation was observed by TUNEL assay. An increase of Bax:Bcl-2 ratio, activation of caspase-9, caspase-3, and cleavage of poly (ADP-ribose) polymerase (PARP) were demonstrated by western blot analysis. Taken together, these results exerted that the MC fraction suppressed human leukemic U937 cell proliferation by inducing apoptosis via the mitochondrial pathway.