• Asian Pacific Journal of Cancer Prevention
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• v.14 no.12
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• pp.7537-7542
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• 2013

Background: Terpinen-4-ol, a monoterpene, is found as the main component of essential oil extracts from many plants. In this study apoptotic and autophagic types of cell death induced by terpinen-4-ol and associated mechanisms were investigated in human leukemic HL-60 cells. Materials and Methods: The cytotoxicity of human leukemic U937 and HL-60 cells was determined by MTT assay. Cytochrome c release, expression of Bax, Bcl-2, Bcl-xl and cleaved Bid were determined by Western blotting. Cell morphology was examined under a transmission electron microscope. LC3-I/II, ATG5 and Beclin-1 levels were detected by immunoblotting. Results: Terpinen-4-ol exhibited cytotoxicity to human leukemic HL-60 but not U937 cells. The apoptotic response to terpinen-4-ol in HL-60 cells was due to induction of cytochrome c release from mitochondria and cleavage of Bid protein after the stimulation of caspase-8. There was a slightly decrease of Bcl-xl protein level. The characteristic cell morphology of autophagic cell death was demonstrated with multiple autophagosomes in the cytoplasm. At the molecular level, the results from Western blot analysis showed that terpinen-4-ol significantly induced accumulation of LC3-I/II, ATG5 and Beclin-1, regulatory proteins required for autophagy in mammalian cells. Conclusions: Terpinen-4-ol induced-human leukemic HL-60 cell death was via both autophagy and apoptosis.

• BMB Reports
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• v.48 no.8
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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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• v.29 no.11
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• pp.1032-1041
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• 2006

Extracellular adenosine 5'-triphosphate (ATP) affects the function of many tissues and cells. To confirm the biological activity of ATP on human myeloid leukemic cells, F-36P and HL-60, cells were treated with a variety of concentrations of ATP. The stimulation with extracellular ATP induced the arrest of cell proliferation and cell death. from the analysis of Annexin-V staining and caspase activity by flow cytometry. The Annexin-V positive cells in both cell lines were dramatically increased following ATP stimulation. The expression of P2 purinergic receptor genes was confirmed, such as P2X1, P2X4, P2X5, P2X7 and P2Y1, P2Y2, P2Y4, P2Y5, P2Y6, P2Y11 in both leukemic cell lines. Interestingly, ATP induced intracellular calcium flux in HL-60 cells but not in F-36P cells, as determined by Fluo-3 AM staining. Cell cycle analysis revealed that ATP treatment arrested both F-36P and HL-60 cells at G1/G0. Taken together, these data showed that extracellular ATP via P2 receptor genes was involved in the cell proliferation and survival in human myeloid leukemic cells, HL-60 and F-36P cells by the induction of apoptosis and control of cell cycle. Our data suggest that treatment with extracellular nucleotides may be a novel and powerful therapeutic avenue for myeloid leukemic disease.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.7
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• pp.3073-3076
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• 2012

Terpinen-4-ol is a terpene found in the rhizome of Plai (Zingiber montanum (Koenig) Link ex Dietr.). In this study apoptogenic activity and mechanisms of cell death induced by terpinen-4-ol were investigated in the human leukemic MOLT-4 cell line. Terpinen-4-ol exhibited cytotoxicity in MOLT-4 cells, with characteristic morphological features of apoptosis by Wright's staining. The mode of cell death was confirmed to be apoptosis by flow cytometric analysis after staining with annexin V-FITC and propidium iodide. A sub-G1 peak in DNA histograms of cell cycle assays was observed. Terpinen-4-ol induced-MOLT-4 cell apoptosis mediated through an intrinsic pathway involving the loss of mitochondrial transmembrane potential (MTP) and release of cytochrome c into the cytosol. In addition, terpinen-4-ol also induced apoptosis via an extrinsic pathway by caspase-8 activation resulting in the cleavage of cytosolic Bid. Truncated-Bid (tBid) translocated to mitochondria and activated the mitochondrial pathway in conjunction with down-regulation of Bcl-2 protein expression. Caspase-3 activity also increased. In conclusion, terpinen-4-ol can induce human leukemic MOLT-4 cell apoptosis via both intrinsic and extrinsic pathways.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.5
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• pp.1977-1981
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• 2012

Houttuynia cordata Thunb (HCT) is a native herb found in Southeast Asia which features various pharmacological activities against allergy, inflammation, viral and bacterial infection, and cancer. The aims of this study were to determine the cytotoxic effect of 6 fractions obtained from silica gel column chromatography of alcoholic HCT extract on human leukemic Molt-4 cells and demonstrate mechanisms of cell death. Six HCT fractions were cytotoxic to human lymphoblastic leukemic Molt-4 cells in a dose-dependent manner by MTT assay, fraction 4 exerting the greatest effects. Treatment with $IC_{50}$ of HCT fraction 4 significantly induced Molt-4 apoptosis detected by annexinV-FITC/propidium iodide for externalization of phosphatidylserine to the outer layer of cell membrane. The mitochondrial transmembrane potential was reduced in HCT fraction 4-treated Molt-4 cells. Moreover, decreased expression of Bcl-xl and increased levels of Smac/Diablo, Bax and GRP78 proteins were noted on immunoblotting. In conclusion, HCT fraction 4 induces Molt-4 apoptosis cell through an endoplasmic reticulum stress pathway.

• BMB Reports
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• v.49 no.1
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• pp.63-68
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• 2016

The serine/threonine kinase mTOR is essential for the phosphoinositide 3-kinases (PI3K) signaling pathway, and regulates the development and function of immune cells. Aberrant activation of mTOR signaling pathway is associated with many cancers including leukemia. Here, we report the contributions of mTOR signaling to growth of human leukemic cell lines and mouse T-cell acute leukemia (T-ALL) cells. Torin, an ATP-competitive mTOR inhibitor, was found to have both cytotoxic and cytostatic effects on U-937, THP-1, and RPMI-8226 cells, but not on Jurkat or K-562 cells. All cells were relatively resistant to rapamycin even with suppressed activity of mTOR complex 1. Growth of T-ALL cells induced by Notch1 was profoundly affected by torin partially due to increased expression of Bcl2l11 and Bbc3. Of note, activation of Akt or knockdown of FoxO1 mitigated the effect of mTOR inhibition on T-ALL cells. Our data provide insight on the effect of mTOR inhibitors on the survival and proliferation of leukemic cells, thus further improving our understanding on cell-context-dependent impacts of mTOR signaling. [BMB Reports 2016; 49(1): 63-68]

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.1
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• pp.475-481
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• 2014

Background: Pereskia sacharosa is a genus of cacti widely used in folk medicine for cancer-related treatment. Anti-proliferative effects have been studied in recent years against colon, breast, cervical and lung cancer cell lines, with promising results. We here extended study of anti-proliferative effects to a blood malignancy, leukemia. Materials and Methods: Two leukemic cell lines, MV4-11 (acute myeloid leukemia) and K562 (chronic myeloid leukemia), were studied. $IC_{50}$ concentrations were determined and apoptosis and cell cycle regulation were studied by flow cytometric analysis. The expression of apoptosis and cell-cycle related regulatory proteins was assessed by Western blotting. Results: P sacharosa inhibited growth of MV4-11 and K562 cells in a dose-dependent manner. The mode of cell death was via induction of intrinsic apoptotic pathways and cell cycle arrest. There was profound up-regulation of cytochrome c, caspases, p21 and p53 expression and repression of Akt and Bcl-2 expression in treated cells. Conclusions: These results suggest that P sacharosa induces leukemic cell death via apoptosis induction and changes in cell cycle checkpoint, thus deserves further study for anti-leukemic potential.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.5
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• pp.2885-2889
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• 2013

Goniothalamin is an active compound extracted from Goniothalamus griffithii, a local plant found in northern Thailand. Goniothalamin inhibits cancer cell growth but is also toxic to normal cells. The aims of this study were to identify the cytotoxic effect of goniothalamin and the mechanism of cell death in human HL-60 and U937 cells. Cytotoxicity was determined by MTT assay and cell cycle profiles were demonstrated by staining with propidium iodide (PI) and flow cytometry. Apoptosis was confirmed by staining with annexin V-FITC/propidium iodide (PI) and flow cytometry. Reduction of mitochondrial transmembrane potential was determined by staining with dihexyloxacarbocyanine iodide and flow cytometry and expression of Smac, caspase-8 and -9 was demonstrated by Western blotting. Goniothalamin inhibited growth of HL-60 and U937 cell lines. An increase of SubG1 phase was found in their cell cycle profiles, indicating apoptosis as the mode of cell death. Apoptosis was confirmed by the flip-flop of phosphatidylserine using annexin V-FITC/PI assay in HL60 and U937 cells in a dose response manner. Furthermore, reduction of mitochondrial transmembrane potential was found in both cell types while expression of caspase-8, -9 and Smac/Diablo was increased in HL-60 cells. Taken together, our results indicate that goniothalamin-treated human leukemic cells undergo apoptosis via intrinsic and extrinsic pathways.

• Biomedical Science Letters
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• v.21 no.2
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• pp.51-59
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• 2015

A humanized mice (hu-mice) model is extremely valuable to verify human cell activity in vivo condition and is regarded as an important tool in examining multimodal therapies and drug screening in tumor biology. Moreover, hu-mice models that simply received human $CD34^+$ blood cells and tissue transplants are also overwhelmingly useful in immunology and stem cell biology. Because generated hu-mice harboring a human immune system have displayed phenotype of human $CD45^+$ hematopoietic cells and when played partly with functional immune network, it could be used to evaluate human cell properties in vivo. Although the hu-mice model does not completely recapitulate human condition, it is a key methodological factor in studying human hematological malignancies with impaired immune cells. Also, an advanced humanized leukemic mice (hu-leukemic-mice) model has been developed by improving immunodeficient mice. In this review, we briefly described the history of development on immunodeficient SCID strain mice for hu-and hu-leukemic-mice model for immunologic and tumor microenviromental study while inferring the potential benefits of hu-leukemic-mice in cancer biology.

• Journal of Ginseng Research
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• v.13 no.2
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• pp.242-247
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• 1989

The effect of ginseng extract and sodium ascorbate (vitamin C) administered separately or in combination on the some cancer cells cultured in vitro have been examined. Mouse leukemic cells (L1210 and P388), human rectal cancer cells (HRT-18) and human colon cancer cells (HCT-48) were used for the experiment. When given separately, the growth rate for each kind of cancer cell was inhibited In proportion to the concentration of ginseng extract or vitamin C. The inhibitory effect on the growth rate of the cancer cells was stronger in ginseng extract than in vitamin C except for the HCT-48 cells. Based on the cytotoxic activity, combined administration of ginseng extract and vitamin C demonstrated a synergistic inhibition of cancer cell growth. The cytotoxic activities of ginseng extract and vitamin C on the mouse leukemic cells were more sensitive than on human colon cancer cells. And the sensitivity of cytotoxic activity was somewhat different in different cancer cell lines.