• Journal of Life Science
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• v.19 no.9
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• pp.1200-1208
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• 2009

Tight junctions (TJs) that act as paracellular permeability barriers play an essential role in regulating the diffusion of fluid, electrolytes and macromolecules through the paracellular pathway. In this study, we investigated the correlation between the tightening of TJs, permeability and the invasive activity of genistein - a bioactive isoflavone of soybeans - in human breast carcinoma MCF-7 and MDA-MB-231 cells. The inhibitory effects of genistein on cell proliferation, motility and invasiveness were found to be associated with the increased tightness of the TJs, which was demonstrated by an increase in transepithelial electrical resistance and a decrease in paracellular permeability. Additionally, the immunoblotting results indicated that genistein repressed the levels of the proteins that comprise the major components of TJ, claudin-3 and claudin-4, which play a key role in the control and selectivity of paracellular transport. Furthermore, genistein decreased the metastasis-related gene expressions of insulin like growth factor-1 receptor and snail, while concurrently increasing that of thrombospondin-1 and E-cadherin. In addition, we demonstrated that claudins play an important role in the anti-motility and invasiveness of genistein using claudin-3 small interfering RNA. Taken together, our results indicate a possible role for genistein as an inhibitor of cancer cell invasion through the tightening of TJs, which may counteract the up-regulation of claudins. In addition, our results indicate that this may be beneficial for the inhibition of tumor metastasis.

• Journal of Life Science
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• v.16 no.4
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• pp.598-604
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• 2006

The $Ca^{2+}-activated$ neutral protease calpain induced proteolysis has been suggested to play a role in certain cell growth regulatory proteins. Cyclin proteolysis is essential for cell cycle progression. D-type cyclins, which form an assembly with cyclin-dependent kinases (cdk4 and cdk6), are synthesized earlier in G1 of the cell cycle and seem to be induced in response to external signals that promote entry into the cell cycle. Here we show that cyclin D3 protein levels are regulated at the posttranscriptional level by calpain protease. Treatment of human breast carcinoma MDA-MB-231 cells with lovastatin and actinomycin D resulted in a loss of cyclin D3 protein that was completely reversible by the peptide aldehyde calpain inhibitor, LLnL. The specific inhibitor of the 26S proteasome, lactacystin, the lysosome inhibitors, ammonium chloride and chloroquine, and the serine protease inhibitor, phenylmethylsulfonylfluoride (PMSF), did not block the degradation of cyclin D3 by lovastatin and actinomycin D. Results of in vitro degradation of cyclin D3 by purified calpain showed that cyclin D3 protein is degraded in a $Ca^{2+}-dependent$ manner, and the half-life of cyclin D3 protein was dramatically increased in LLnL treated cells. These data suggested that cyclin D3 protein is regulated by the $Ca^{2+}-activated$ protease calpain.

• Nutrition Research and Practice
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• v.12 no.2
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• pp.129-134
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• 2018

BACKGROUND/OBJECTIVES: Although several recent studies have reported the anti-cancer effects of extracts or components of Citrus unshiu peel, which has been used for various purposes in traditional medicine, the molecular mechanisms for their effects remain unclear. In the present study, the anti-cancer activity of a water-soluble extract of C. unshiu peel (WECU) in MDA-MB-231 human breast carcinoma cells at the level of apoptosis induction was investigated. MATERIALS/METHODS: Cytotoxicity was evaluated using the MTT assay. Apoptosis was detected using DAPI staining and flow cytometry analyses. Mitochondrial membrane potential, reactive oxygen species (ROS) assay, caspase activity and Western blotting were used to confirm the basis of apoptosis. RESULTS: The results indicated that WECU-induced apoptosis was related to the activation of caspase-8, and -9, representative initiator caspases of extrinsic and intrinsic apoptosis pathways, respectively, and caspase-3 accompanied by proteolytic degradation of poly(ADP-ribose) polymerase and down-regulation of the inhibitors of apoptosis protein family members. WECU also increased the pro-apoptotic BAX to anti-apoptotic BCL-2 ratio, loss of mitochondrial membrane potential and cytochrome c release from mitochondria to cytoplasm. Furthermore, WECU provoked the generation of ROS, but the reduction of cell viability and induction of apoptosis by WECU were prevented when ROS production was blocked by antioxidant N-acetyl cysteine. CONCLUSIONS: These results suggest that WECU suppressed proliferation of MDA-MB-231 cells by activating extrinsic and intrinsic apoptosis pathways in a ROS-dependent manner.

• Biomedical Science Letters
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• v.11 no.2
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• pp.175-183
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• 2005

The two major isoflavones in soy, genistein and daidzein, are well known to prevent hormone-dependent cancers by their anti estrogenic activity. The exact molecular mechanisms for the protective action are, however, not provided yet. It has been reported that genistein and daidzein have a potential anticancer activity through their antiproliferative effect in many hormone-dependent cancer cell lines. Transforming growth $factor-\beta1(TGF-\beta1)$ has also been found to have cell growth inhibitory effect, especially in mammary epithelial cells. This knowledge led to a hypothetical mechanism that the soy isoflavones-induced growth inhibitory effect can be derived from the regulation of $TGF-\beta1$ and $TGF-\beta$ receptors. In order to test this hypothesis, the effects of the soy isoflavones at various concentrations and periods on the expression of $TGF-\beta1$and $TGF-\beta$ receptors were investigated by using Northern blot analysis in human breast carcinoma epithelial cell lines, an estrogen receptor positive cell line (MCF-7) and an estrogen receptor negative cell line (MDA-MB-231). As a result, only genistein has shown a profound dose-dependent effect on $TGF-\beta1$ expression in the $ER^+$ cell line within the range of doses tested, and the expression levels are correspondent to their inhibitory activities of cell growth. Moreover, daidzein showed down-regulated $TGF-\beta1$ expression at a low dose, the cell growth proliferation was promoted at the same condition. Therefore, antiproliferative activity of the soy isoflavones can be mediated by $TGF-\beta1$ expression, and the effects are mainly, if not all, occurred by ER dependent pathway. The expression of $TGF-\beta$ receptors was induced at a lower dose than the one for $TGF-{\beta}1$ induction regardless of the presence of ER, and the expression patterns are similar to those of the cell growth inhibition. These results indicated that the regulation of $TGF-\beta$ receptor expression as well, prior to $TGF-\beta1$ expression, may be involved in the antiproliferative activity of soy isoflavones. Little or no expression of $TGF-\beta$ receptors was found in the MCF-7 and MDA-MB-231 cells, suggesting refractory properties of the cells to growth inhibitory effect of the $TGF-\beta$. The soy isoflavones can seemingly restore the sensitivity of growth inhibitory responses to $TGF-\beta1$ by re-inducing $TGF-\beta$ receptors expression. In conclusions, our findings presented in this study show that the antitumorigenic activity of the soy isoflavones could be mediated by not only $TGF-\beta1$induction but $TGF-\beta$ receptor restoration. Thus, soy isoflavones could be good model molecules to develop new nonsteroidal antiestrogenic chemopreventive agents, associated with, regulation of $TGF-\beta$ and its receptors.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.4
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• pp.410-415
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• 2008

This study was performed to observe the antimutagenic and cytotoxic activities of methanol extract of kochujang added with sea tangle and deep sea water salts (SDK) and kochujang added with sea tangle (SK) using the Ames test and SRB assay, respectively. The direct antimutagenic effect of SDK and SK methanol extracts were examined by Ames test using Salmonella Typhimurium TA98 and TA100. In the Ames test, methanol extract of SDK and SK alone did not exhibit mutagenicity and most of the samples showed high antimutagenic effects against mutation induced by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) and 4-nitroquinoline-1-oxide (4NQO). Methanol extract of SDK ($200{\mu}g$/plate) showed approximately 71.4% inhibitory effect on the mutagenesis induced by 4NQO against TA98 strain; whereas 56.1% and 83.6% inhibitions were observed on the mutagenensis induced by 4NQO and MNNG against TA100 strain. The cytotoxic effects of SDK and SK increased with increasing sample concentration against human cervical adenocarcinoma (HeLa), human hepatocellular carcinoma (Hep3B), human breast adenocarcinoma (MCF-7), human stomach adenocarcinoma (AGS), and human lung carcinoma (A549). The SDK at the concentration of 1 mg/ml showed cytotoxicities of 61.5%, 61.3%, 51.4%, 57.9% and 77.7% against HeLa, Hep3B, MCF-7, AGS and A549, respectively. In contrast 1 mg/ml treatment of SDK and SK methanol extract had only $2{\sim}38%$ cytotoxicity on human transformed primary embryonal kidney cell (293).

• Korean Journal of Food Science and Technology
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• v.32 no.6
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• pp.1371-1378
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• 2000

This study was performed to determine the antimutagenic and cytotoxic effect of Agaricus blazei Murill methanol extract on Salmonella typhimurium TA98, TA100 and human cancer cell lines using Ames test and cytotoxicity assay, respectively. In Ames test, methanol extract from A. blazei Murill did not exhibit any mutagenicity and most of the samples showed high antimutagenic effects against mutation induced by N-methyl-N'-nitro-N-nitrosoguanidine(MNNG), 4-nitroquinoline-1-oxide(4NQO), 3-amino-1,4-dimethyl-5H-pyrido [4,3-b] indol(Trp-P-1) and $benzo({\alpha})pyrene(B({\alpha})P)$. The methanol extracts of A. blazei Murill$(200\;{\mu}g/plate)$ showed approximately 92.4%, 81.9% and 83.4% inhibitory effect on the mutagenesis induced by 4NQO, Trp-P-1 and $B({\alpha})P$ against TA98 strain, whereas 87.3%, 94.7%. 92.3% and 89.9% inhibitions were observed on the mutagenesis induced by MNNG, 4NQO, Trp-P-1 and $B({\alpha})P$ against TA100 strain. The solvent fractions of methanol extracts from A. blazei Murill except water fraction showed high antimutagenic effects of $70{\sim}90%$ against mutation induced by MNNG, 4NQO. Trp-P-1 and $B({\alpha})P$. In anticancer effects of A. blazei Murill extract and fraction against cancer cell lines including human breast adenocarcinoma(MCF7), human lung carcinoma(A549), human fibrosarcoma(HT1080), human hepatocellular carcinoma(Hep3B), human epitheloid carcinoma(HeLa), human gastric carcinoma(KATO III) and human chronic myelogenous leukemia(K562) were investigated. The treatment of 1 mg/mL A. blazei Murill extracts had the highest cytotoxicity with 91.9% against HeLa, followed by KATO III(88.7%), A549(86.5%) and Hpe3B(84.3%). Whereas 1 mg/mL treatment of A. blazei Murill extracts had only $10{\sim}40%$ cytotoxicity on human normal liver cell (WRL68).

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.5
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• pp.921-927
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• 2001

This study was performed to investigated the effects on the cytotoxicity and antigenotoxicity of Cordyceps militaris extracts on the human cancer cell lines. The ethanol extract and five fractions which were hexane, chloroform, ethylacetate, butanol and aqueous were screened for crytotoxicity on human lung carcinoma(A549). human breast adenocarcinoma (MCF-7) human epitheloid carcinoma(HeLa), human fibrosarcoma(HT1080) human hepatocellular carcinoma(Hep3B), human gastric carcinoma(KATOIII) and chronic myelogenous leukemia(K562) cell by SRB and MTT assays. The results showed that growth inhibition rates of the human cancer cell in the presence of Cordyceps militaris were inhibited with increasing concentration of the extract. The ethanol extract from Cordyceps militaris had strong inhibitory effects in1 mg/mL treatment by SRB assay , showing 89.4%, 85.7%, 72.9% and 65.5% inhibition in HT1080, HeLa, Hep3B and A549, respectively. The treatment of 1 mg/mL hexane fraction by SRB assay had the strongest cytotoxicity with 97.0% on HT1080 followed by MCF-7(92.9%) and HeLA(90.3%). The inhibition ration on KATOIII by MTT assay was much higher in the butanol (83.7%) and aqueous (80.4%) than in the ethanol extract (61.5%) And also, K562 showed similar tendency with KATOIII. The effects of Cordyceps militaris extracts on the frequencies of micronucleated polychromatic erythrocytes (MNPCEs) induced by N-methyl-N-nitro-N-nitrosoguanidime(MNNG) were investigated in the bone-marrow cells of ICR male mice. The amount of 10, 20, 40 and 80 mg/kg of each extract were administered to animals immediately after injection of MNNG, and the exposure time was 36 hours. Significant reductions(p<0.05) with 39.7%, 52.7%, 71.4% and 83.9% were observed in the frequencies of MNPCE when 10, 20, 40 and 80 mg/kg of the hexane fraction of Coryceps militarus extracts were given to the mice.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.4
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• pp.516-523
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• 2015

This study investigated the antimutagenic and anticancer effects of Platycodon grandiflorum extract (PGE) and its fractions against carcinogenic N-nitrosodimethylamine (NDMA) and genotoxicity. The Ames Salmonella mutagenicity test employing histidine mutants of Salmonella Typhimurium TA98 and TA100 was used to examine the mutagenicity of PGE and its fractions. Bacterial reversion assay with S. Typhimurium TA98 and TA100 did not show a significantly increased number of revertant colonies. The same test was used to examine the ability of PGE and its fractions to prevent acquisition of N-methyl-N'-nitro-N-nitrosoguanidine- and 4-introquino-line-1-oxide-induced mutations. PGE and its fractions inhibited mutagenesis in a dose-dependent manner. Among the fractions, ethyl acetate fraction from PGE (PGEA) exhibited a higher antimutagenic effect than other fractions. PGE and its fractions suppressed the growth of cancer cell lines, including human cervical adenocarcinoma, human hepatocellular carcinoma, human breast adenocarcinoma, human lung carcinoma, and transformed primary human embryonic kidney cells. In addition, we evaluated the antitumor activity of PGEA and its fractions in sacorma-180 solid tumor-bearing mice. In vivo anticancer activity results showed that PGE and its fractions could more effectively suppress tumor growth than the control. PGEA showed higher in vitro and in vivo anticancer effects than PGE and other fractions, and PGEA inhibited NDMA formation. Thus, we showed that PGEA has antimutagenic and anticancer activities, making it a candidate anticancer material under these experimental conditions.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.2
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• pp.143-148
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• 2007

This study was to investigate the mixed buckwheat flour quality by observing antimutagenic and cytotoxic effects of mixed buckwheat flour extracts using Ames test and SRB (sulforhodamine B) assay. Samples were prepared to the ratio of 100% (B1), 90% (BF1), 80% (BF2), 70% (BF3) and 60% (BF4) (w/w) flour buckwheat based on wheat flour weight. The initial pasting temperature in an amylograph was increased according to the increase of the buckwheat flour. The water absorption in farinograph decreased with the addition of buckwheat flour. The inhibition rates of B1, BF3 and BF4 extract (160 g/plate) were 45%, 37.3% and 42% against the mutagenesis of Salmonella Typhimurium TA100 induced by MNNG $(0.4{\mu}g/plate)$, respectively. In addition, the B1 at the same concentration showed 64% and 44.3% inhibition on the mutagenesis of Salmonella Typhimurium TA98 and TA100 induced by 4NQO $(0.15{\mu}g/plate)$, respectively. In SRB assay, human breast adenocarcinoma (MCF 7), human hepatocellular carcinoma (Hep3B), human stomach adonocarcinoma (AGS), human lung carcinoma (A549) and human cervical adenocarcinoma (HeLa) proliferations were inhibited by the increase in the sample concentration.

• Korean Journal of Animal Reproduction
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• v.27 no.3
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• pp.259-268
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• 2003

Lactadherin (formerly known as BA46), a major glycoprotein of the human milk fat globule membrane, is abundant in human breast milk and breast carcinoma cells and is known to prevent symptomatic rotavirus infections. In this study, we tried to transfer the human lactadherin gene to the Chinese Hamster Ovary (CHO) cells using retrovirus vector system and tested inducible expression of the gene under the tetracycline-controllable promoter. At first, tetracycline-mediated inducibility was tested using E.coli LacZ marker gene. NIH3T3 cells co-infected with RevTet-On and RevTRE-LacZ retrovirus vectors showed that the cells responded to doxycycline (a derivative of tetracycline) in a dose-dependent manner, and prominent induction of the lacZ gene expression was observed from 1 $\mu\textrm{g}$/ml of doxycycline concentration. Based on the results of the pilot experiment, inductional expression of the human lactadherin gene was conducted using RevTet-On and RevTRE-Ltd retrovirus vectors. Analysis with the RT-PCR demonstrated successful inductional expression of the lactadherin gene in the Chinese Hamster Ovary (CHO) cells. Considering that constitutive overexpression of the exogenous genes in the target cells causes serious physiological imbalance, the results obtained in this study will be very useful especially in the studies of gene therapy and transgenic animal production.