• 한국독성학회:학술대회논문집
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• 한국독성학회 2001년도 International Symposium on Dietary and Medicinal Antimutgens and Anticarcinogens
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• pp.56-57
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• 2001

Modulation of events characteristic of carcinogenesis or of cancer cells is being emphasized as a rational strategy to combat cancer. This is achieved through chemoprevention by a variety of agents. Phenolic compounds, particularly polyphenols, have been shown to be highly active in this regard. Certain cellular and molecular events relevant to carcinogenesis are modified by polyphenols. The present investigation has been carried out to examine some of these aspects.(omitted)

• 한국독성학회:학술대회논문집
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• 한국독성학회 2001년도 International Symposium on Effects of Edible Phytochemicals and Their Synthetic Derivatives on Carcinogenesis and Mutagenesis
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• pp.13-14
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• 2001

Modulation of events characteristic of carcinogenesis or of cancer cells is being emphasized as a rational strategy to combat cancer. This is achieved through chemoprevention by a variety of agents. Phenolic compounds, particularly polyphenols, have been shown to be highly active in this regard. Certain cellular and molecular events relevant to carcinogenesis are modified by polyphenols. The present investigation has been carried out to examine some of these aspects.(omitted)

• 생약학회지
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• 제32권4호통권127호
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• pp.269-273
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• 2001

Ethanol extracts from Xanthii Fructus (XFE) and Prunellae Spica (PSE) were investigated for the effects on the induction of cancer chemoprevention-associated enzymes. The following effects were measured: (a) induction of quinone reductase (QR) (b) induction of glutathione S-transferase (GST) (c) reduced glutathione (GSH) level. XFE and PSE were potent inducers of quinone reductase activity in Hepa1c1c7 murine hepatoma cells. Glutathione levels were increased with XFE and PSE. In addition, glutathione S-transferase activity was increased with XFE. However, GST activity was not increased with PSE. These results suggest that XFE and PSE have chemopreventive potentials by inducing quinone reductase and increasing GSH levels.

• 한국독성학회:학술대회논문집
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• 한국독성학회 2002년도 Current Trends in Toxicological Sciences
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• pp.92-92
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• 2002

Recently we have reported that various hydroxystilbenes show strong inhibition of human P450 1 activity. A series of synthetic trans-stilbene derivatives were prepared and their inhibitory potentials were evaluated with the bacterial membrane of recombinant human P450 1A1, 1A2 or 1B1 coexpressed with human P450/NADPH-450 reductase to find new candidates for cancer chemoprevention.(omitted)

• 한국독성학회:학술대회논문집
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• 한국독성학회 2001년도 International Symposium on Dietary and Medicinal Antimutgens and Anticarcinogens
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• pp.11-12
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• 2001

Selenium is known to have both chemopreventive and therapeutic benefits of cancer. Recent studies have implicated that apoptosis is one of the most plausible mechanism of chemopreventive effects of selenium compounds and tumor invasion is a new factor involved in chemotherapy. In the present study, we demonstrate that Se-methylselenocysteine(MSC), one of the most effective selenium compound sat chemoprevention, induces apoptosis in HL-60 cells and that ROS plays a crucial role in MSC-induced apoptosis.(omitted)

• 한국식품영양과학회지
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• 제29권2호
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• pp.316-321
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• 2000

This study carried out to eluciate the cancer chemoprevention of Korean native fermented food, baechu kimchi using Comet assay (in other words, single cell microgel electrophoresis). For this purpose, baechu kimchi was fractionated by water, n-hexane, chloroform and ethyl acetate. 5 strains of dominant fermented bacteria were isolated from baechu kimchi. The water fraction, n-hexane fraction, chloroform fraction, ethyl acetate fraction and water insoluble fractions showed no antigenotoxicitie in non-tumoral normal 3T3 cells. Among 5 bacteria isolates from baechu kimchi, two isolates bacteria 1 and 2 strongly inhibited genotoxicity of N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) in non-tumoral normal 3T3 cells (p<0.05). Bacteria 3, 4 and 5 were also not antigenotoxic.

• BMB Reports
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• 제36권1호
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• pp.43-48
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• 2003

Understanding the process of carcinogenesis will involve both the accumulation of many scientific facts derived from molecular, biochemical, cellular, physiological, whole animal experiments and epidemiological studies, as well as from conceptual understanding as to how to order and integrate those facts. From decades of cancer research, a number of the "hallmarks of cancer" have been identified, as well as their attendant concepts, including oncogenes, tumor suppressor genes, cell cycle biochemistry, hypotheses of metastasis, angiogenesis, etc. While all these "hallmarks" are well known, two important concepts, with their associated scientific observations, have been generally ignored by many in the cancer research field. The objective of the short review is to highlight the concept of the role of human adult pluri-potent stem cells as "target cells" for the carcinogenic process and the concept of the role of gap junctional intercellular communication in the multi-stage, multi-mechanism process of carcinogenesis. With these two concepts, an attempt has been made to integrate the other well-known concepts, such as the multi-stage, multi-mechanisn or the "initiation/promotion/progression" hypothesis; the stem cell theory of carcinogenesis; the oncogene/tumor suppression theory and the mutation/epigenetic theories of carcinogenesis. This new "integrative" theory tries to explain the well-known "hallmarks" of cancers, including the observation that cancer cells lack either heterologous or homologous gap junctional intercellular communication whereas normal human adult stem cells do not have expressed or functional gap junctional intercellular communication. On the other hand, their normal differentiated, non-stem cell derivatives do express connexins and express gap junctional intercellular communication during their differentiation. Examination of the roles of chemical tumor promoters, oncogenes, connexin knock-out mice and roles of genetically-engineered tumor and normal cells with connexin and anti-sense connexin genes, respectively, seems to provide evidence which is consistent with the roles of both stem cells and gap junctional communication playing a major role in carcinogenesis. The integrative hypothesis provides new strategies for chemoprevention and chemotherapy which focuses on modulating connexin gene expression or gap junctional intercellular communication in the premalignant and malignant cells, respectively.

• Nutritional Sciences
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• 제2권2호
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• pp.71-75
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• 1999

Epidemiologic studies consistently demonstrate an inverse relationship between risk for colon canter and consumption of fruits and vegetables. Wheat bran, flax and soy contain dietary fiber and phytochemicals, such as lignans and isoflavones, that may inhibit colon carcinogenesis. Orange juice contains hesperidin, a flavanone glucoside that protects against colon carcinogenesis. This study determined if feeding orange juice, wheat bran, soy and flaxseed (combined diet) would inhibit azoxymethane (AOM) induced colon cancer. Cancer was initiated in male Fisher 344 rats by injecting 15 mg AOM/kg of weight at 22 and 29 days of age. One week after the second AOM injection, rats (N = 30) in the combined diet group received dry diet containing wheat bran (4%), soy with ethanol soluble phytochemirals(13%) and flaxseed (8%) and orange juice replaced drinking water. The control group remained on the control diet and received distilled water to drink. The rats were killed 28 weeks later, and colon tissues and tumors were removed for histologic analysis. Feeding the combined diet significantly reduced tumor incidence (p < 0.05), however tumor multiplicity was not changed (p > 0.05, 0.9 tumors/rat fed the combined diet vs 1.2 for controls). Also, tumor burden was only marginally reduced in rats fed the combined diet vs control rats (65 vs 210 mg of tumor/rats, respectively). The reduction in tumor incidence was associated with a decreased labeling index and proliferation zone in normal appearing colon mucosa. Therefore, this study shows that phytochemicals in wheat bran, soy, flax and orange juice reduce colon carcinogenesis, presumably by decreasing cell proliferation and enhancing cell differentiation.

• Asian Pacific Journal of Cancer Prevention
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• 제13권12호
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• pp.6403-6407
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• 2012

Detoxifying enzymes are present in most epithelial cells of the human gastrointestinal tract where they protect against xenobiotics which may cause cancer. Induction of examples such as glutathione S-transferase (GST) and its thiol conjugate, glutathione (GSH) as well as NAD(P)H: quinoneoxidoreductase (NQO1) facilitate the excretion of carcinogens and thus preventing colon carcinogenesis. Pterostilbene, an analogue of resveratrol, has demonstrated numerous pharmacological activities linked with chemoprevention. This study was conducted to investigate the potential of pterostilbene as a chemopreventive agent using the HT-29 colon cancer cell line to study the modulation of GST and NQO1 activities as well as the GSH level. Initially, our group, established the optimum dose of 24 hours pterostilbene treatment using MTT assays. Then, effects of pterostilbene ($0-50{\mu}M$) on GST and NQO1 activity and GSH levels were determined using GST, NQO1 and Ellman assays, respectively. MTT assay of pterostilbene ($0-100{\mu}M$) showed no cytotoxicity toward the HT-29 cell line. Treatment increased GST activity in the cell line significantly (p<0.05) at 12.5 and $25.0{\mu}M$. In addition, treatment at $50{\mu}M$ increased the GSH level significantly (p<0.05). Pterostilbene also enhanced NQO1 activity significantly (p<0.05) at $12.5{\mu}M$ and $50{\mu}M$. Hence, pterostilbene is a potential chemopreventive agent capable of modulation of detoxifiying enzyme levels in HT-29 cells.

• 한국해양바이오학회지
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• 제1권2호
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• pp.71-75
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• 2006

별불가사리 단백추출물을 조제하여 유방암 유발억제효과를 측정한 결과, 별불가사리 단백추출물은 estrogen-의존성의 유방암세포(MCF-7)와 estrogen-비의존성 유방암세포(MDA-MB-231)의 증식을 농도의존적으로 억제하는 효과가 있었으며, 유방암발생 발암물질 활성에 관여하는 cytochrome P450 1A1 활성도 저해하였다. 또한 유방암발생의 촉진단계에 주요한 기능을 가진 ODC 활성도 억제하였으므로 별불가사리 단백추출물은 유방암 발생을 저해할 것으로 기대된다.