• BMB Reports
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• 제35권4호
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• pp.377-383
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• 2002

Arsenic trioxide ($As_O_3$) was recently demonstrated to be an effective inducer of apoptosis in patients with relapsed acute promyelocytic leukemia (APL) as well as patients with APL in whom all-trans-retinoic acid and conventional chemotherapy failed. Chronic myelogenous leukemia cells are highly resistant to chemotherapeutic drugs. To determine if $As_O_3$ might be useful for the treatment of chronic myelogenous leukemia, we examined the ability of $As_O_3$ to induce apoptosis in K562 cells. In vitro cytotoxicity of $As_O_3$ was evaluated in K562 cells by a MTT assay: the $IC_50$ value for $As_O_3$ was determined to be $10\;{\mu}m$. When analyzed by agarose gel electorphoresis, the DNA fragments became evident after incubation of the cells with $20\;{\mu}m$ $As_O_3$ for 24 h. We also found morphological changes and chromatin condensation of the cells undergoing apoptosis. Activation of caspase-3 was observed 6 h after treatment with $20\;{\mu}m$ $As_O_3$ by a Western blot analysis. Next, we examined the MAP kinase-signaling pathway of $As_O_3$-induced apoptosis in K562 cells. $As_O_3$ at $10\;{\mu}m$ strongly induced the activation of p38, inhibited $As_O_3$ induced apoptotic cell death. These results suggest that $As_O_3$ is able to induce the apoptotic activity in K562 cells, and its apoptotic mechanism may be associated with the activation of p38.

• Clinical and Experimental Pediatrics
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• 제55권7호
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• pp.249-253
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• 2012

We report a case of a 13-year-old girl with acute lymphoblastic lymphoma- leukemia, who presented with a cardiac metastasis in the right ventricle, resulting in a pulmonary embolism. At the time of her leukemia diagnosis, a cardiac mass was incidentally found. The differential diagnosis for this unusual cardiac mass included cardiac tumor, metastasis, vegetation, and thrombus. Empirical treatment was initiated, including anticoagulation and antibiotics. She underwent plasmapheresis and was administered oral prednisolone for her leukemia. Five days later, she experienced sudden hemodynamic collapse and required extracorporeal membrane oxygenation insertion and emergency surgery. These interventions proved futile, and the patient died. Pathology revealed that the cardiac mass comprised an aggregation of small, round, necrotic cells consistent with leukemia. This is the first known case of acute lymphoblastic leukemia presenting as a right ventricular mass, with consequent fatal acute pulmonary embolism. A cardiac mass in a child with acute leukemia merits investigation to rule out every possible etiology, including vegetation, thrombus, and even a mass of leukemic cells, which could result in the fatal complication of pulmonary embolism.

• Preventive Nutrition and Food Science
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• 제9권3호
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• pp.265-269
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• 2004

Prunus mandshurica var. glabra Nakai (Rosaceae) is widely distributed in South Korea and bears a fruit with a bitter and astringent taste. An ethyl acetate-soluble extract of Prunus mandshurica was found to exhibit significant cytotoxicity against human leukemia cell lines. Bioassay-directed fractionation of this extract using an MTT(3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) cell proliferation assay as a monitor led to the isolation of the bioactive compounds. Two compounds, 1 and 2 were subsequently found to mediate cytotoxicity against U937, human monocytic leukemia cells. The 50% growth inhibitory concentrations ($IC_{50}$/) of compounds 1 and 2 on U937 were 40 and 62 $\mu\textrm{g}$/mL, respectively.

• 대한의생명과학회지
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• 제24권2호
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• pp.134-137
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• 2018

S100A8 and S100A9 are involved in pathogenesis of cancer by induction or inhibition of cancer as well as inflammation. In this study, we investigated the association of S100A8 and S100A9 with pathogenesis of leukemia using human monocytic leukemia cells, THP-1. The expression of TLR4, which is a known receptor of S100A8 and S100A9, was examined by using flow cytometry and Western blotting. THP-1 cells have high surface and cytosol expression of TLR4. S100A8 and S100A9 suppressed the cell survival, and this suppression was found to be associated with apoptosis because they increased the number of apoptotic cells in a dose- and a time-dependent manners. However, S100A8 and S100A9 had no effect on the survival and apoptosis of monocytes isolated from the peripheral blood. We next examined the apoptotic effect of lipopolysaccharide (LPS) and monophosphoryl lipid A (MPLA), which are other ligands of TLR4, in THP-1 cells. Lipopolysaccharide had no effect on cell survival, but MPLA is effective on the cell apoptosis. These results suggest that S100A8 and S100A9 may regulate leukemia cell survival via TLR4, which is an essential receptor in the pro-apoptotic mechanism induced by S100A8 and S100A9. These findings may shed light on development of a possible therapeutic drug for leukemia treatment.

• BMB Reports
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• 제48권8호
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• pp.427-428
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• 2015

Despite high interests on microenvironmental regulation of leukemic cells, little is known for bone marrow (BM) niche in leukemia patients. Our recent study on BMs of acute myeloid leukemia (AML) patients showed that the mesenchymal stromal cells (MSCs) are altered during leukemic conditions in a clinical course-dependent manner. Leukemic blasts caused reprogramming of transcriptomes in MSCs and remodeling of niche cross-talk, selectively suppressing normal primitive hematopoietic cells while supporting leukemogenesis and chemo-resistance. Notably, differences in BM stromal remodeling were correlated to heterogeneity in subsequent clinical courses of AML, i.e., low numbers of mesenchymal progenitors at initial diagnosis were correlated to complete remission for 5-8 years, and high contents of mesenchymal progenitor or MSCs correlated to early or late relapse, respectively. Thus, stromal remodeling by leukemic cell is an intrinsic part of leukemogenesis that can contribute to the clonal dominance of leukemic cells over normal hematopoietic cells, and can serve as a biomarker for prediction of prognosis. [BMB Reports 2015; 48(8): 427-428]

• Archives of Pharmacal Research
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• 제26권11호
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• pp.912-916
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• 2003

Four known lanostane triterpenoids, schiprolactone A (1), schisanlactone B (2), nigranoic acid (3) and schisandronic acid (4) Were isolated from the stems of Schisandra henryi for the first time. Their structures were characterized by IR, MS and NMR techniques. Compounds 1, 2 and 4 showed moderate cytotoxic activity against Leukemia cells in vitro. Cytotoxic activity of compounds 1-4 showed $IC_{50}$ of 0.0097, 0.01, 0.097 and 0.0099 $\mu$ mol/mL respectively toward Leukemia cells and $IC_{50}$ of 0.097, 0.1, 0.097 and 0.099 $\mu$mol/mL toward Hela cells respectively. It is the first report that these compounds possess cytotoxic activity on Leukemia and Hela cells.

• Molecules and Cells
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• 제43권2호
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• pp.198-202
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• 2020

Comprehensive inhibition of RUNX1, RUNX2, and RUNX3 led to marked cell suppression compared with inhibition of RUNX1 alone, clarifying that the RUNX family members are important for proliferation and maintenance of diverse cancers, and "cluster regulation of RUNX (CROX)" is a very effective strategy to suppress cancer cells. Recent studies reported by us and other groups suggested that wild-type RUNX1 is needed for survival and proliferation of certain types of leukemia, lung cancer, gastric cancer, etc. and for their one of metastatic target sites such as born marrow endothelial niche, suggesting that RUNX1 often functions oncogenic manners in cancer cells. In this review, we describe the significance and paradoxical requirement of RUNX1 tumor suppressor in leukemia and even solid cancers based on recent our findings such as "genetic compensation of RUNX family transcription factors (the compensation mechanism for the total level of RUNX family protein expression)", "RUNX1 inhibition-induced inhibitory effects on leukemia cells and on solid cancers through p53 activation", and "autonomous feedback loop of RUNX1-p53-CBFB in acute myeloid leukemia cells". Taken together, these findings identify a crucial role for the RUNX cluster in the maintenance and progression of cancers and suggest that modulation of the RUNX cluster using the pyrrole-imidazole polyamide gene-switch technology is a potential novel therapeutic approach to control cancers.

• 대한의생명과학회지
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• 제27권2호
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• pp.95-98
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• 2021

The S100 family proteins act as inducers of cancer cell apoptosis and inflammatory mediators. This study examined the pro-apoptotic mechanism caused by S100A8 and S100A9 in human FIP1L1-PDGFRα-positive eosinophilic leukemia cells. S100A8 and S100A9 elicited the death of EoL-1 cells in a time and dose-dependent manner. The activation of PDGFRα was suppressed by a decrease in PDGFRα after treatment with S100A8 and S100A9. Cycloheximide, a translation inhibitor, suppressed PDGFRα expression from 1 h to 5 h, and a co-treatment with S100A8 and S100A9 boosted the decrease in expression. The phosphorylation and expression of STAT5 decreased after treatment with S100A8 and S100A9 in EoL-1 and imatinib-resistant (EoL-1-IR) cells. S100A8 and S100A9 induced the chemotaxis of EoL-1 cells but did not affect the chemoattraction of EoL-1-IR. These findings indicate the cell death mechanism due to S100 family proteins and the development of leukemia therapy using S100A8 and S100A9.

• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-2
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• pp.167.2-168
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• 2003

Anticancer drug resistance occasionally occurs in malignant hematologic diseases such as acute myelocytic leukemia (AML) treated with chemotherapy and is a major problem to complete remission. Malignant cells primarily induce intrinsic resistance to treatment of anticancer drug, but gradually obtain acquired resistance to cytotoxic activities of chemotherapy. In this study, we monitored the expression profiles of doxorubicin resistance-related genes in AML-2/DX100, a doxorubicin-resistant human acute myelocytic leukemia cell line. (omitted)

• 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.