• Journal of Life Science
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• v.17 no.6 s.86
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• pp.778-782
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• 2007

The Diphenyleneiodonium (DPI) is widely used as an inhibitor of flavoenzymes, particularly NADPH oxidase. In this study, we investigated the effect of DPI on the cell growth progression of human colon cancer cells HCT-116 (wild-type p53), HT-29 (p53 mutant) and human breast cancer cells MCF-7 (wild-type p53). DPI treatment in cancer cells evoked a dose- and time-dependent growth inhibition, and also induced the cell cycle arrest in C2/M phase. The peak of cell population arrested in C2/M phase was observed at12 hr after treatment of DPI. In addition, DPI significantly induced the expression of p53, which induces proapoptotic genes in response to DNA damage or irreparable cell cycle arrest, at 6 hr in DPI-stimulated cells. However, a catechol apocynin, which inhibits the assembly of NADPH oxidase, did not induce p53 expression. This suggest that p53 expression induced by DPI is not associated with the inhibition of NADPH oxidase. In conclusion, we suggest that DPI induces the expression of wild-type p53 by ROS-in-dependent mechanism in several cancer cells, and upregulated p53 may be involved in regulatory mechanisms for growth inhibition and cell cycle arrest at C2/M phase in DPI-stimulated cells.

• Korean Journal of Food Science and Technology
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• v.34 no.4
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• pp.688-693
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• 2002

The anticarcinogenic effects of various food components have received much attention in recent years. However mechanism of anticarcinogens in food materials on cancer cells have rarely been investigated. This study was performed to investigate the effects on the cytotoxicity and quinone reductase (QR) activity of Allium tuberusum (AT) on the human cancer cells. The six partition layers which are methanol (ATM), hexane (ATMH), ethylether (ATMEE), ethylacetate (ATMEA), butaonl (ATMB) and aqueous (ATMA) of Allium tuberusum were screened for their cytotoxic effects on HepG2, MCF-7, HeLa and SK-N-MC cells by the MTT assay. Among the six partition layers, ATMEE had the strongest cytotoxic effect at concentration of $150\;{\mu}g/mL$ which resulted over 95% on HepG2, HeLa, MCF-7 and SK-N-MC cell lines. The ATMEA also showed significant cytotoxic effect on HepG2 and SK-N-MC cell lines. The ATMB showed the highest induction activity of QR on HepG2 cells among the other partition layers. QR activity of HepG2 cells, grown in the presence of ATMB at the concentration of $50\;{\mu}g/mL$, was increased by 3.9 times, compared to the control value of 1.0. Based on these results, the ATMEE and ATMB may have potentially anticarcinogenic and chemopreventive activities.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.2
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• pp.322-328
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• 2000

This study was performed to determine the antimutagenic and cytotoxic effect of the Phellinus linteus methanol extract on Salmonella typhimurium TA98, TA100 and human cancer cell lines. In the Ames test, methanol extract of P. linteus alone did not exhibit any mutagenicity but showed substantial inhibitory effects against mutation induced by N-methyl-N'-nitro-N-nitrosoguanidine(MNNG), 4-nitroquinoline-nitroquinoline-1-oxide(4NQO), 3-amino-1,4-dimethyl-5H-pyrdo[4,3-blindol(Trp-P-1) and benzo(α)pyrene(B(α)P). The methanol extracts of P. linteus(200㎍/plate) showed approximately 78.3%, 78.7% and 88.1% inhibitory effect on the mutagenesis induced by 4NQO, Trp-P-1 and B(α)P. The anticancer effects of P. linteus extract against human breast adenocarcinoma(MCF7), human lung carcinoma (A549), human fibrosarcoma (HT1080), human hepatocelular carcinoma (Hep3B) and human epitheloid carcinoma (HeLa) were investigated. The treatment of 1mg/mL P. linteus extracts had the highest cytotoxicity against MCF7 (92.0%), followed by Hep3B (84.9%), A549 (84.2%) and HT1080 (82.9%). In contrast 1mg/mL treatment of P. linteus extracts had only 10∼40% cytotoxicity on normal human liver cell (WRL68).

• Journal of Life Science
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• v.28 no.10
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• pp.1201-1211
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• 2018

The study compared the anti-aging, anti-adipogenesis, and anti-tumor effects of epigallocatechin-3- gallate (EGCG) in various cancer cell lines (SNU-601, MKN74, AGS, MCF-7, U87-MG, and A-549) and normal cell lines (MRC-5 fibroblasts, dental tissue-derived mesenchymal stem cells [DSC], and 3T3-L1 pro-adipocytes). Half inhibitory concentration ($IC_{50}$) values were significantly (p<0.05) higher in normal cell lines (~50 uM), when compared to that in cancer cell lines (~10 uM). For anti-aging effects, MRC-5 and DSC were exposed to 10 uM EGCG for up to five passages that did not display any growth arrest. Population doubling time and senescence-related ${\beta}-galactosidase$ ($SA-{\beta}-gal$) activity in treated cells were similar to untreated cells. For anti-adipogenic effects, mouse 3T3-L1 pre-adipocytes were induced to adipocytes in an adipogenic differentiation medium containing 10 uM EGCG, but adipogenesis in 3T3-L1 cells was not inhibited by EGCG treatment. For anti-tumor effects, the cancer cell lines were treated with 10 uM EGCG. PDT was significantly (p<0.05) increased in EGCG-treated SNU-601, AGS, MCF-7, and U87-MG cancer cell lines, except in MKN74 and A-549. The level of telomerase activity and cell migration capacity were significantly (p<0.05) reduced, while $SA-{\beta}-gal$ activity was highly up-regulated in EGCG treated-cancer cell lines, when compared to that in untreated cancer cell lines. Our results have demonstrated that EGCG treatment induces anti-tumor effects more efficiently as noted by decreased cell proliferation, cell migration, telomerase activity, and increased $SA-{\beta}-gal$ activity than inducing anti-aging and anti-adipogenesis. Therefore, EGCG at a specific concentration can be considered for a potential anti-tumor drug.

• Molecules and Cells
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• v.25 no.2
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• pp.305-311
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• 2008

After successful clinical application, arginine deiminase (ADI) has been proposed to be a new cancer therapeutic. In the present study, we examined the effect of ADI in combination with ionizing radiation (IR) on MCF-7 cell growth and clonogenic cell death. Cell growth was inhibited by IR in a dose-dependent manner and ADI enhanced the radiosensitivity. ADI itself did not suppress the growth of MCF-7 cells due to the high level of expression of argininosuccinate synthetase (ASS), which convert citrulline, a product of arginine degradation by ADI, to arginine. Previously, it was suggested that ammonia, another product of arginine degradation by ADI, is the main cause of the growth inhibition of irradiated hepatoma cells contaminated with ADI-expressing mycoplasma [van Rijn et al. (2003)]. However, we found that ammonia is not the only factor that enhances radiosensitivity, as enhancement was also observed in the absence of ammonia. In order to identify the enhancing effect, levels of ASS and proteins related to the cell cycle were examined. ASS was unchanged by ADI plus IR, but p21 (a CDK inhibitor) was upregulated and c-Myc downregulated. These findings indicate that changes in the expressions of cell cycle proteins are involved in the enhancement of radiosensitivity by ADI. We suggest that ADI is a potential adjunct to cancer therapy.

• Molecules and Cells
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• v.20 no.3
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• pp.378-384
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• 2005

Estrogen metabolites are carcinogenic. The comparative mitogenic activities of $17{\beta}$-estradiol (E2) and four metabolites, 2-hydroxyestradiol (2-OHE2), 4-hydroxyestradiol (4-OHE2), $16{\alpha}$-hydroxyestrone ($16{\alpha}$-OHE1) and 2-methoxyestradiol (2-ME), were determined in estrogen receptor(ER)-positive MCF-7 human breast cancer cells. Each of the E2 metabolites caused proliferation of the MCF-7 cells, but only E2 and $16{\alpha}$-OHE1 induced a greater than 20-fold increases in transcripts of the progesterone receptor (PR) gene, a classical ER-mediated gene. This suggests that the mitogenic action of E2 and $16{\alpha}$-OHE1 could result from their effects on gene expression via the ER. E2 metabolites altered the expression of E2-regulated proteins including heat shock proteins (Hsps). $16{\alpha}$-OHE1 and 2-ME as well as E2 increased levels of Hsp56, Hsp60, $Hsp90{\alpha}$ and Hsp110 transcripts, and the patterns of these inductions resembled that of PR. Hsp56 and Hsp60 protein levels were increased by all the E2 metabolites. Levels of the transcripts of 3 E2-upregulated proteins (XTP3-transactivated protein A, protein disulfide isomerase-associated 4 protein and stathmin 1) and an E2-downregulated protein (aminoacylase 1) were also affected by the E2 metabolites. These results suggest that the altered expression of Hsps (especially Hsp56 and Hsp60) by E2 metabolites such as E2, $16{\alpha}$-OHE1 and 2-ME could be closely linked to their mitogenic action.

• Food Science and Preservation
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• v.11 no.4
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• pp.461-467
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• 2004

Antioxidant effect of traditional doenjang(TD) was reduced by increasing of maturation period. Methanol fractionate of TD matured for 1 year showed strong antioxidant effect against linoleic acid, following the order of hexane and water layer. Antioxidant effect in lipophilic and hydrophilic extracts of TD were gradually increased according to increasing maturation period, whereas their values or two extracts were lower than those or fractionates from TD. Hydrogen-scavenging effect in hydrophobic extract, methanol and butanol fractionates of TD were much higher than those of the other samples. Chloroform and ethylacetate fractionates were markedly lower in the range of $10.57{\sim}22.84\%\;and\;7.82{\sim}22.58\%$, respectively. Anticarcinogenic effect of extracts and fractionates from TD were higher in water fractionates for A549 cell (human lung carcinoma) and methanol fractionates fur MCF-7 cell (human breast adenocarcinoma). Especially, inhibitory effect for growth of cancer cell was increased by the increasing maturation period of TD.

• Molecules and Cells
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• v.24 no.1
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• pp.95-104
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• 2007

The mechanism of acacetin-induced apoptosis of human breast cancer MCF-7 cells was investigated. Acacetin caused 50% growth inhibition ($IC_{50}$) of MCF-7 cells at $26.4{\pm}0.7{\mu}M$ over 24 h in the MTT assay. Apoptosis was characterized by DNA fragmentation and an increase of sub-G1 cells and involved activation of caspase-7 and PARP (poly-ADP-ribose polymerase). Maximum caspase 7 activity was observed with $100{\mu}M$ acacetin for 24 h. Caspase 8 and 9 activation cascades mediated the activation of caspase 7. Acacetin caused a reduction of Bcl-2 expression leading to an increase of the Bax:Bcl-2 ratio. It also caused a loss of mitochondrial membrane potential that induced release of cytochrome c and apoptosis inducing factor (AIF) into the cytoplasm, enhancing ROS generation and subsequently resulting in apoptosis. Pretreatment of cells with N-acetylcysteine (NAC) reduced ROS generation and cell growth inhibition, and pretreatment with NAC or a caspase 8 inhibitor (Z-IETD-FMK) inhibited the acacetin-induced loss of mitochondrial membrane potential and release of cytochrome c and AIF. Stress-activated protein kinase/c-Jun $NH_4$-terminal kinase 1/2 (SAPK/JNK1/2) and c-Jun were activated by acacetin but extracellular-regulated kinase 1/2 (Erk1/2) nor p38 mitogen-activated protein kinase (MAPK) were not. Our results show that acacetin-induced apoptosis of MCF-7 cells is mediated by caspase activation cascades, ROS generation, mitochondria-mediated cell death signaling and the SAPK/JNK1/2-c-Jun signaling pathway, activated by acacetin-induced ROS generation.

• Food Science and Preservation
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• v.11 no.2
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• pp.214-220
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• 2004

This study was carried out to determine the antioxidative, antimutagenic, and anticancer effects of functional food manufactured from fermented soybean(FFMFS) using DPPH free radical donating method, Ames test and cytotoxicity, respectively. FFMFS extracted with ethanol and then further fractionated to n-hexane, chloroform, ethyl acetate(EtOAc), butanol and water, stepwise. Among five fractions, the EtOAc fractions showed highest electron donating activities (31.6 $\mu\textrm{g}$/mL). The inhibition rate of ethanol extract(200 $\mu\textrm{g}$/plate) of FFMFS in the S. typhimurium TA100 strain showed 84.8% against the mutagenesis induced by MNNG. In addition, the suppression of EtOAc fractions with same concentration of FFMFS the S. typhimurium TA98 and TA100 strains showed 88.7% and 92.8% inhibition against Trp-P-l, respectively. The cytotoxic effects of FFMFS against the cell lines with human lung carcinoma(A549), human gastric carcinoma(AGS) and human breast adenocarcinoma(MCF-7) were inhibited with the increase of the extract concentration. The treatment of 1.0 mg/mL FFMFS of EtOAc fraction showed strong cytotoxicities of 84.5%, 88.7% and 85.6% against A549, AGS and MCF-7, respectively.

• Journal of Life Science
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• v.22 no.7
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• pp.964-969
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• 2012

Genistein, a predominant isoflavone, has been shown to inhibit the growth of various cancer cells in vitro and in vivo without toxicity to normal cells. In the present study, we investigated the effects of genistein on the activity and the expression of matrix metalloproteinases (MMPs) in MCF-7 and MDA-MB-231 human breast adenocarcinoma cells. Our findings showed that MMP-9 and -2 activation was significantly increased in response to 12-O-tetradecanoyl phorbol-13-acetate (TPA). However, the increased activities of MMP-9 and -2 in TPA-treated cells were concentration-dependently inhibited by treatment with genistein, and this was also correlated with a decrease in the expression of their mRNA and proteins. In addition, a matrigel invasion assay showed that genistein reduced TPA-induced invasion of MCF-7 and MDA-MB-231 cells. Although further in vivo studies are needed, these results suggest that genistein treatment may inhibit tumor cell invasion and, therefore, act as a dietary source to decrease the risk of cancer metastasis.