• Food Science and Preservation
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• v.12 no.1
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• pp.80-85
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• 2005

The effect of 12 edible mushroom species on the antioxidant and cytotoxicity on cancer cells were studied Methanol extract of Lyophyllum ulmarium, Cordyceps militaris and Sarcodon aspratus showed $30\~60\%$ DPPH radical scavenging activity and $39\~53\%$ protective effects against the cytotoxicity of $B_2O_2$. Methanol extracts of Sarcodon aspratus, Lyophyllum ulmarium, Cordyceps militaris, Agaricus blazei and Ganoderma lucidum revealed high inhibitive activities in cytotoxicity on human leukemia tells such as promyelocytic leukemia cell (HL60) and histiocytic lymphoma cell (U937). Highest toxicity was observed against HL60 cells in Sarcodon aspratus methanol extract showing $70.5\%$ inhibition at 1mg/mL whereas Cordyceps militaris methanol extract showed $81.5\%$ inhibition against U937 cells. Most water extracts of edible mushrooms exhibited the lowest effect against HL60 and U937 cells compared to methanol extract. These extract did not show cytotoxic effects against human lymphocyte. Results revealed 5 kinds of edible murshroom (Cordyceps militaris, Agaricus blaxei, Lyophyllum ulmarium, Ganoderma lucidum and Sarcodon aspratus) have strong antioxidative and in vitro anticancer efforts.

• Journal of Life Science
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• v.18 no.1
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• pp.96-102
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• 2008

Piceatannol is a polyphenol that is found in abundant quantities in grapes and wine. Although recent experimental data revealed the anti-cancer potency of piceatannol, the molecular mechanisms underlying the antileukemic activity have not yet been studied in detail. In the present study, we investigated further possible mechanisms by which piceatannol exerts its anti-proliferative action in cultured human leukemia U937 cells. Exposure of U937 cells to piceatannol resulted in growth inhibition and induction of apoptosis as measured by MTT assay and flow cytometry analysis, which was associated with S phase arrest of the cell cycle. Piceatannol treatment markedly inhibited the activity of telomerase, and the levels of human telomerase reverse transcriptase (hTERT) and telomerase-associated protein-1 (TEP-1), main determinants of the telomerase enzymatic activity, were progressively down-regulated by piceatannol treatment in a dose-dependent fashion. However, the levels of cyclooxygenases (COXs) expression and prostaglandin E2 (PGE2) release were not changed in piceatannol-treated U937 cells. Taken together, these findings provide important new insights into the possible molecular mechanisms of the anti-cancer activity of piceatannol.

• Journal of Physiology & Pathology in Korean Medicine
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• v.19 no.2
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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.

• Journal of Life Science
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• v.19 no.7
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• pp.871-877
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• 2009

We investigated the effects of sodium butyrate, a histone deacetylase inhibitor, on the cell cycle progression in human monocytic leukemia U937 cells. Exposure of U937 cells to sodium butyrate resulted in growth inhibition, G1 arrest of the cell cycle and induction of apoptosis in a dose-dependent manner as measured by MTT assay and flow cytometry analysis. The increase in G1 arrest was associated with the down-regulation in cyclin D1, E, A, cyclin-dependent kinase (Cdk) 4 and 6 expression, and up-regulation of Cdk inhibitors such as p21 and p27. Sodium butyrate treatment also inhibited the phosphorylation of retinoblastoma protein (pRB) and p130, however, the levels of transcription factors E2F-1 and E2F-4 were not markedly modulated. Furthermore, the down-regulation of phosphorylation of pRB and p130 by this compound was associated with enhanced binding of pRB and E2F-1, as well as p130 and E2F-4, respectively. Overall, the present results demonstrate a combined mechanism involving the inhibition of pRBjp130 phosphorylation and induction of Cdk inhibitors as targets for sodium butyrate that may explain some of its anti-cancer effects in U937 cells.

• 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 the Korean Society of Food Science and Nutrition
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• v.23 no.3
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• pp.443-452
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• 1994

This study describes the effects of novel1, 25-dihydroxyvitamin D$_3$ analong[1,25(OH)$_2$-16ene-23yne-26, 27-F6-D$_3$] on proliferation of the human histiocytic lymphoma cell line U937 in vitro. We also examined the expression of c-myc oncogene in U937 cells was apparently inhibited to 62% and 87% of the control level after 4 days in the presence of 10-8M and 10-7 M of this analog, respectively. This compound morpholgically and functionally differentiated U937 cells to nonocyte-macrophage phenotype showing the increase of adherence ability to surface and a decrease of N/C ratio in Giemsa staining . Especially, nonspecific esterase activity which is a marker of cell differentiation to monocyte-macrophage was positive, and production of the positive stained cells increased in a dose dependent fashion . The expression of c-myc oncogene by 1, 25(OH)$_2$D$_3$ analog(10-7 M) was reduced by 60% at the mRNA level as determined by Northern blotting. The effects of this novel analog on cell proliferation and cell differentiation may open op new therapeutic strategies for human disorders such as psoriassis and may provide a tool to understand the mechanism of action of vitamin D$_3$ seco-steroids in malignancy.

• Journal of Life Science
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• v.25 no.2
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• pp.249-255
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• 2015

Schisandrae fructus [Schizandra chinensis (Turcz.) Baillon] is a medicinal herb widely used for treating various inflammatory and immune diseases in East Asian countries. The Schisandrae Semen essential oil (SSeo) from this plant has pharmacological activities, including antioxidant, antimicrobial, and antitumoral activities. Nevertheless, the biological activities and underlying molecular mechanisms of the potential anti-cancer effects of this oil remain unclear. In the present study, we investigated the potential inhibition of apoptosis signaling pathways by SSeo in human leukemia U937 cells and evaluated the underlying molecular mechanism. Exposure to SSeo resulted in a concentration-dependent growth inhibition due to apoptosis, which was verified by DNA fragmentation, the presence of apoptotic bodies, and an increase in the sub-G1 ratio. Induction of apoptotic cell death by SSeo was correlated with the down-regulation of members of the inhibitor of apoptosis protein (IAP) family (including X-linked inhibitor of apoptosis protein (XIAP), cIAP-1, and surviving) and anti-apoptotic Bcl-2, and with up-regulation of death receptor (DR) 4 and DR5, depending on dosage. SSeo treatment also induced Bid truncation, mitochondrial dysfunction, proteolytic activation of caspase-3, -8 and -9, and concomitant degradation of activated caspase-3 target proteins such as poly (ADP-ribose) polymerase. Taken together, these findings suggest that SSeo may be a potential chemotherapeutic agent for use in the control of human leukemia cells. Further studies are needed to identify its active compounds.

• Preventive Nutrition and Food Science
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• v.11 no.1
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• pp.17-24
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• 2006

Methanolic and aqueous extracts from 37 seaweed species (10 green and 27 brown seaweeds) collected from Jeju Island coast were prepared at high ($70^{\circ}C$) and room ($20^{\circ}C$) temperatures and examined for cytotoxic activity against 4 tumor cell lines: U937 (human monoblastoid leukemia cell line), HL60 (human promyelocytic leukemia cell line), HeLa (woman cervical carcinoma cell line) and CT26 (mouse colon carcinoma line). Both MeOH extracts of Desmarestia tabacoides and Dictyota dichotoma possessed strong cytotoxic activities against all the tumor cell lines tested, but the aqueous extract exhibited no activity. On the other hand Ecklonia cava showed strong cytotoxic activities for the $20^{\circ}C$ aqueous extract against the three tumor cells except HeLa cell. Sagassum coreanum and Sagassum siliquastrum $20^{\circ}C$ aqueous extracts also exhibited strong cytotoxic activities against U937, HL60, HeLa cells. Even though green seaweeds showed less activity than brown seaweeds, $20^{\circ}C$ aqueous extracts of Codium contractum and Codium fragile exhibited strong cytotoxic activities against HL60 or CT26 cells, respectively.

• Food Science and Biotechnology
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• v.15 no.3
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• pp.369-373
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• 2006

Water extracts obtained from cultured mountain ginseng (CMG) were evaluated for their ability to stimulate immune cells and inhibit cancer cell proliferation. The lymphocyte subpopulation in mouse splenocytes in vivo was significantly increased by the administration of the CMG extract (27.4 mg/mouse). Interleukin-2 and ${\gamma}$-interferon in the mice serum increased up to 30% in CMG extract-treated mice. At a concentration of 1.37 mg/mL, nitric oxide increased up to 400% in the macrophage cell line treated with CMG extract. The CMG extract significantly retarded the proliferation of human acute promyelocytic (HL60), human histiocytic (U937), and mouse lymphocytic (L1210) leukemia cell lines in vitro at concentrations over 2.74-13.7 mg/mL. In addition, CMG extract treatments (1.37 mg/mL and 2.74 mg/mL) lead to the increased expression of the p53 gene and protein in cultured U937 leukemia cell lines. These results indicate that water extracts of CMG are capable of both immune cell stimulation and cancer cell growth inhibition.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.9
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• pp.4827-4834
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• 2012

Tumor suppressor genes have received much attention for their roles in the development of human malignancies. Gelsolin has been found to be down-regulated in several types of human cancers, including leukemias. It is, however, expressed in macrophages, which are the final differentiation derivatives for the monocytic myeloid lineage, implicating this protein in the differentiation process of such cells. In order to investigate the role of gelsolin in leukaemic cell differentiation, stable clones over-expressing ectopic gelsolin, and a control clone were established from U937 leukaemia cells. Unlike the control cells, both gelsolin-overexpressing clones displayed retarded growth, improved monocytic morphology, increased NADPH and NSE activities, and enhanced surface expression of the ${\beta}$-integrin receptor, CD11b, when compared with the parental U937 cells. Interestingly, RT-PCR and western blot analysis also revealed that gelsolin enhanced p21CIP1 mRNA and protein expression in the overexpressing clones. Moreover, transient transfection with siRNA silencing P21CIP1, but not the control siRNA, resulted in a reduction in monocytic differentiation, accompanied by an increase in proliferation. In conclusion, our work demonstrates that gelsolin, by itself, is capable of inducing monocytic differentiation in U937 leukaemia cells, most probably through p21CIP1 activation.