• The Korean Journal of Applied Statistics
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• v.24 no.4
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• pp.609-622
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• 2011

The pattern of methylation draws significant attention from cancer researchers because it is believed that DNA methylation and gene expression have a causal relationship. As the interest in the role of methylation patterns in cancer studies (especially drug resistant cancers) increases, many studies have been done investigating the association between gene expression and methylation. However, a model-based approach is still in urgent need. We developed a finite mixture model in the Bayesian framework to find a possible relationship between gene expression and methylation. For inference, we employ Expectation-Maximization(EM) algorithm to deal with latent (unobserved) variable, producing estimates of parameters in the model. Then we validated our model through simulation study and then applied the method to real data: wild type and hydroxytamoxifen(OHT) resistant MCF7 breast cancer cell lines.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.24
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• pp.10613-10619
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• 2015

Background: Both alcohol and aqueous extracts of Sauromatum giganteum(Engl.) Cusimano and Hett, the dried root tuber of which is named Baifuzi in Chinese, have been used for folklore treatment of cancer in Northeast of China. However, little is known about which is most suitable to the cancer therapy. Materials and Methods: Serum pharmacology and MTT assays were adopted to detect the effects of ethanol and aqueous extracts of Sauromatum giganteum(Engl.) Cusimano and Hett, prepared by heat reflux methods, on proliferation of different cancer cells. Results: Cancer cells treated with medium supplemented with 10%, 20%, 40% serum(v/v) containing ethanol extract had a decline in viability, with inhibition rates of 7.69%, 21.8%, 41.9% in MCF-7 cells, 42.8%, 48.1%, 51.8% in SGC-7901 cells, 44.1%, 49.2%, 53.7% in SMMC-7721 cells, 6.8%, 15.2%, 39.8% in HepG2 cells, 7.57%, 16.3%, 36.2% in HeLa cells, 6.24%, 12.5%, 27.4% in A549 cells, and 7.20%, 17.5%, 31.3% in MDA-MB-231 cells, respectively. Viability in the aqueous extract groups was no different with that of controls. Conclusions: An ethanol extract of Sauromatum giganteum(Engl.) Cusimano and Hett inhibited the proliferation of SMMC-7721, SGC-7901 and MCF-7 cells, which supports the use of alcoholic but not aqueous extracts for control of sensive cancers, which might include hepatocarcinoma, gastric cancer and breast cancer.

• Proceedings of the Korean Society of Applied Pharmacology
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• 2001.11a
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• pp.112-112
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• 2001

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is an environmental toxin that activates the aryl hydrocarbon receptor (AhR) and disrupts multiple endocrine signaling pathways by enhancing ligand metabolism, altering hormone synthesis, down regulating receptor levels, and interfering with gene transcription. And TCDD-mediated gene transactivation via the AhR has been shown to be dependent upon estrogen receptor (ER) expression in human breast cancer cells. In the present study, we have examined the effect of natural estrogen, phytoestrognes and environmental estrogens on the regulation of CYP1A1 gene expression in MCF-7 human breast cancer cell line. that ER and AhR are co-expressed. pCYP1A1 -luc reporter gene was transiently transfected into MCF-7 cells. These cells were treated with various chemicals and then luciferase assay was carried out. 17be1a-estradiol significantly inhibited TCDD stimulated luciferase activity dose dependently and this inhibition was partially recovered by concomitant treatment of tamoxifen. 17beta-estradiol metabolites, 2-hydroxyestradiol and 16alpha-estriol resulted in less potent inhibitory effect than estradiol and synthetic estrogen, diethylstilbestrol (DES) showed no effect on CYP1A1 gene expression. This study demonstrated that estrogen down-regulated TCDD stimulated CYP1A1 expression via ER mediation. And we have found out that several flavonoids such as genistein, kaempferol, daidzein, naringenin, and alkylphenols such as nonylphenol, 4-octylphenol and resveratrol also inhibited TCDD induced CYP1A1 expression like estrogen.

• Korean Journal of Veterinary Research
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• v.45 no.1
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• pp.85-91
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• 2005

Much of the interest on the chemopreventive properties of herbs and plants has been raised, whereas little is regarding to anti-tumor effect of farming and aquatic products. In the present study, the anti-tumor effect of hot-water extract of a seaweed, BLC (Sargassum fulvellum) and BLC/HEN egg was investigated using MCF-7 cells in vitro and in vivo systems. We found that the BLC extract and BLC/HEN egg inhibited cell proliferation in a dose-dependent manner, which might be mediated through up-regulation of p53. Furthermore, this test compound can directly induce apoptosis in MCF-7 cells, which might be mediated through up-regulation of a pro-apoptotic Bax protein and down-regulation of a anti-apoptotic Bcl-2 protein, not by immune system. Nude mice bearing established breast tumors (with exogenous estradiol) were treated with BLC extract and BLC/HEN egg. Treatment BLC extract and BLC/HEN egg caused a 42% and 71% inhibition of tumor growth, respectively. Both agents caused a significant inhibition of volume and weight growth of estrogen independent human breast tumors established from MCF-7 cells. Our results suggested that BLC extract and BLC/HEN egg have the efficacious effect of human breast cancer not only in vitro but also in vivo.

• Food Science and Biotechnology
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• v.18 no.1
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• pp.108-112
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• 2009

Antioxidant and anticancer effects of methanolic extracts from the flesh (WFME) and peel (WPME) of white onion, the flesh (YFME) and peel (YPME) of yellow onion, the flesh (RFME) and peel (RPME) of red onion were studied. The content of total phenolics in WFME, WPME, YPME, YFME, RPME, and RFME were $0.260{\pm}0.01$, $4.480{\pm}0.23$, $0.319{\pm}0.02$, $719.12{\pm}37.36$, $0.248{\pm}0.01$, and $806.21{\pm}26.38\;mg/g$, respectively. The quercetin content of WFME, WPME, YFME, YPME, RFME, and RPME were $12.56{\pm}0.19$, $3.57{\pm}0.14$, $15.24{\pm}0.65$, $755.29{\pm}22.24$, $5.70{\pm}0.23$, and $774.03{\pm}29.48\;mg$/100 g, respectively. Like total phenolics, the highest 2,2'-diphenyl-1-picrylhydrazyl (DPPH) scavenging activities were found in RPME. However, inhibitory effects on lipid oxidation of RPME were similar to those of WPME and YPME. In addition, inhibitory effect of WPME, YPME, and RPME for human breast cancer cell (MCF-7) growth were 78.43, 81.90, and 96.52% while those on human prostate cancer cell (LNcap) were 71.58, 77.93, and 98.47% at $100{\mu}g/mL$, respectively. Total phenolics, quercetin content, antioxidant, and anticancer activities exhibited significant variation among the 3 onion varieties in this experiment. Therefore, it is assumed that antioxidant and anticancer activities were affected by the total phenolics and quercetin level of onion.

• Proceedings of the PSK Conference
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• 2003.04a
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• pp.183.2-184
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• 2003

Zinc is known to have an inhibitory effect on apoptosis and an antioxidative effect scavenging reactive oxygen species (ROS) under oxidative stress. We studied the influence of zinc on cadmium-induced apoptosis especially associated with ROS in MCF-7 human breast carcinoma cell line. For the determination of appropriate experimental concentration and time, we excecuted MTT [3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide] assay and DNA fragmentation assay. (omitted)

• Molecular & Cellular Toxicology
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• v.5 no.1
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• pp.67-74
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• 2009

Exposures to environmental chemicals that mimic endogenous hormones are proposed for a number of adverse health effects, including infertility, abnormal prenatal and childhood development and above all cancers. In addition, recently miRNA (micro RNA) has been recognized to play an important role in various diseases and in cellular and molecular responses to toxicants. In this study, endocrine disrupting environmental toxicant, nonylphenol (NP) was treated to MCF-7 (Human breast cancer cell) and HepG2 (Human hepatocellular liver carcinoma) cell line at 3 hrs and 48 hrs time point and miRNA analysis using $mirVana^{TM}$ miRNA bioarray was performed and compared with total mRNA microarray data for the same cell line and treatment. Robust data quality was achieved through the use of dye-swap. Analysis of microarray data identifies a total of 20 and 11 miRNA expressions at 3 hrs and 48 hrs exposure to NP in MCF-7 cell line and a total of 14 and 47 miRNA expression at 3 hrs and 48 hrs exposure respectively to NP in HepG2 cell line. Expression profiling of the selected miRNA (let-7c, miR-16, miR-195, miR-200b, miR200c, miR-205, and miR-589) reveals changes in the expression of target genes related to metabolism, immune response, apoptosis, and cell differentiation. The present study can be informative and helpful to understand the role of miRNA in molecular mechanism of chemical toxicity and their influence on hormone dependent disease. Also this study may prove to be a valuable tool for screening potential estrogen mimicking pollutants in the environment.

• Biomolecules & Therapeutics
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• v.22 no.4
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• pp.347-354
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• 2014

Larrea nitida is a plant that belongs to the Zygophyllaceae family and is widely used in South America to treat inflammatory diseases, tumors and menstrual pain. However, its pharmacological activity remains unclear. In this study we evaluated the property of selective estrogen receptor modulator (SERM) of Larrea nitida extracts (LNE) as a phytoestrogen that can mimic, modulate or disrupt the actions of endogenous estrogens, depending on the tissue and relative amount of other SERMs. To investigate the property of SERM of LNE, we performed MCF-7 cell proliferation assays, estrogen response element (ERE)-luciferase reporter gene assay, human estrogen receptor (hER) binding assays and in vivo uterotrophic assay. To gain insight into the active principles, we performed a bioassay-guided analysis of LNE employing solvents of various polarities and using classical column chromatography, which yielded 16 fractions (LNs). LNE showed high binding affinities for $hER{\alpha}$ and $hER{\beta}$ with $IC_{50}$ values of $1.20{\times}10^{-7}$ g/ml and $1.00{\times}10^{-7}$ g/ml, respectively. LNE induced $17{\beta}$-estradiol (E2)-induced MCF-7 cell proliferation, however, it reduced the proliferation in the presence of E2. Furthermore, LNE had an atrophic effect in the uterus of immature rats through reducing the expression level of progesterone receptor (PR) proteins. LN08 and LN10 had more potent affinities for binding on $hER{\alpha}$ and ${\beta}$ than other fractions. Our results indicate that LNE had higher binding affinities for $hER{\beta}$ than $hER{\alpha}$, and showed SERM properties in MCF-7 breast cancer cells and the rat uterus. LNE may be useful for the treatment of estrogen-related conditions, such as female cancers and menopause.

• Biomolecules & Therapeutics
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• v.27 no.6
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• pp.591-602
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• 2019

Human breast cancer cell line, MDA-MB-231, is highly invasive and aggressive, compared to less invasive cell line, MCF-7. To explore the genes that might influence the malignancy of MDA-MB-231, DNA microarray analysis was performed. The results showed that G0/G1 switch 2 (G0S2) was one of the most highly expressed genes among the genes upregulated in MDA-MB-231. Although G0S2 acts as a direct inhibitor of adipose triglyceride lipase, action of G0S2 in cancer progression is not yet understood. To investigate whether G0S2 affects invasiveness of MDA-MB-231 cells, G0S2 expression was inhibited using siRNA, which led to decreased cell proliferation, migration, and invasion of MDA-MB-231 cells. Consequently, G0S2 inhibition inactivated integrin-regulated FAK-Src signaling, which promoted Hippo signaling and inactivated ERK1/2 signaling. In addition, G0S2 downregulation decreased ${\beta}$-catenin expression, while E-cadherin expression was increased. It was demonstrated for the first time that G0S2 mediates the Hippo pathway and induces epithelial to mesenchymal transition (EMT). Taken together, our results suggest that G0S2 is a major factor contributing to cell survival and metastasis of MDA-MB-231 cells.

• Natural Product Sciences
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• v.27 no.1
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• pp.18-27
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• 2021

Eight cytotoxic constituents, consisting of six triterpenoids, cabralealactone (1), cabraleadiol (2), prototiamin A (3), 23-desmethyllimocin B (5), melianodiol (7) and indicalilacol (8) along with one limonoid, neemfruitins A (4) and one protolimonoid, protoxylocarpin G (6), were isolated from the extract of n-hexane of the stembark of Chisocheton pentandrus. The chemical structures were identified on the basis of spectroscopic evidence and compared to previously reported spectra. These isolated compounds appear for the first time in the plant. Compounds 1 - 8 were evaluated for their cytotoxic effect against MCF-7 breast cancer lines in vitro. Among the isolated compounds, melianodiol (7) showed the strongest cytotoxic activity with IC50 values of 16.8 µM.