• Radiation Oncology Journal
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• v.21 no.3
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• pp.207-215
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• 2003

Purpose: Extracellular signal-regulated kinase (ERK), which is part of the mitogen-activated protin kinase cascade, opposes initiation of the apoptotic cell death which is programmed by diverse cytotoxic stimuli. In this regard, the inhibition of ERK may be useful in improving the therapeutic efficacy of established anticancer agents. Materials and Methods: Murine hepatocarcinoma, HCa-I is known to be highly radioresistant with a TCD50 (radiation dose yield in $50\%$ cure) of more than 80 Gy. Various anticancer drugs have been found to enhance the radioresponse of this particular tumor but none were successful. The objective of this study was to explore whether the selective inhibition of MEK could potentiate the antitumor efficacy of radiation in vivo, particularly in the case on radioresistant tumor. C3H/HeJ mice hearing $7.5\~8\;mm$ HCa-I, were treated with PD98059(intratumoral injection of $0.16\;\mug/50\;\mul$). Results: Downregulation on ERK by PD98059 was most prominent 1h after the treatment. In the tumor growth delay assay, the drug was found to Increase the effect of the tumor radioresponse with an enhancement factor (EF) of 1.6 and 1.87. Combined treatment of 25 Gy radiation with PD98059 significantly increased radiation induced apoptosis. The peak apoptotic index (number on apoptotic nuclei in 1000 nuclei X100) was $1.2\%$ in the case of radiation treatment alone, $0.9\%$ in the case of drug treatment alone and $4.9\%,\;5.3\%$ in the combination treatment group. An analysis of apoptosis regulating molecules with Western blotting showed upregulation of p53, p$p21^{WAF1/CIP1}\;and\;Bcl-X_s$ in the combination treatment group as compared to their levels in either the radiation alone or drug alone treatment groups. The level of other molecules such as $Bcl-X_L4, Bax and Bcl-2 were changed to a lesser extent. Conclusion: The selective inhibition of MEK in combination with radiation therapy may have potential benefit in cancer treatment.

• Tuberculosis and Respiratory Diseases
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• v.47 no.5
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• pp.650-659
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• 1999

Background/Aims: It is well recognized that all aerobic cells have the protective mechanisms in order to minimize the tissue damage induced by various reactive oxygen species(ROS). Thioredoxin peroxidase(TPX) which has been recently identified and characterized functions to convert peroxide to water. The protein is also found in various subtypes(TPX-A & B, MER5, HS22 and HORF-06) and is known to be ubiquitous in most human cells. Especially, ischemic brain injuries, partial hepatectomy and radiation induced DNA damages. In treating lung cancer, radiation therapy has a major place in the local control and the relief of symptoms, but radiation induced free radical injury and resulting pulmonary fibrosis has been the major drawback of the therapy. However, little is known about the protective mechanisms and biologic modulations against radiation-induced tissue damages. Methods: Eighteen mice were divided into six groups, 3 in each group, and fifteen had received 900cGy of radiation. The mice were sacrificed according to the pre determined time schedule; immediate, 1, 2, 3 and 6 weeks after irradiation. Extracts were made from the lungs of each mice, Western blot analysis of various subtypes of TPX were done after SDS-P AGE. Examination of H & E stained slides from the same irradiated specimens and the control specimens were also performed. Results: No difference in the intensity of the immunoreactive bands in the irradiated lung samples of the mice compared to the unirradiated control was observed regardless of the time intervals, although H & E examination of the sample specimens demonstrated progressive fibrotic changes of the irradiated lung samples. Conclusion: In conclusion, according to our data, it is suggested that various thioredoxin peroxidase subtypes and catalase which are known to be increased in many repair processes may not be involved in the repair of the radiation injury to the lung and subsequent fibrosis.

• Journal of Ginseng Research
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• v.30 no.3
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• pp.117-127
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• 2006

Ginseng is a medicinal herb widely used in Asian countries. Dendritic cells(DCs) play a pivotal role in the initiation of T cell-mediated immune responses, making them an attractive cellular adjuvant for use in cancer vaccines. In this study, we examined the effects of Red-ginseng(water extract, edible and fermented ethyl alcohol extract, crude saponin) on the DCs phenotypic and functional maturation. Immature DCs were cultured in the presence of GM-CSF and IL-4, and the generated immature DCs were stimulated by water extract, edible and fermented ethyl alcohol extract, crude saponin and LPS, respectively, for 24hours. The expression of surface co-stimulatory molecules, including MHC(major histocompatibility complex) class II, CD40, CD80 and CD86, was increased on DCs that were stimulated with crude saponin, but antigen-uptake capacity was decreased. The antigen-presenting capacity of Red-ginseng extracts-treated DCs as analyzed by allogeneic T cells proliferation and IL-2, $IFN-{\gamma}$ production was increased. Furthermore, $CD4^+$ and $CD8^+$ syngeneic T cell(OVA-specific) proliferation and $IFN-{\gamma}$ production was significantly increased. However, $CD4^+$ syngeneic T cell secreted higher levels of IL-2 in responding but not $CD8^+$ syngeneic T cell. These results indicate the immunomodulatory properties of Red-ginseng extracts, which might be therapeutically useful in the control of cancers and immunodeficient diseases through the up-regulation of DCs maturation.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.1
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• pp.147-152
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• 2000

Various lines of evidence suggest that dietary components protect the initiation of carcinogenesis. In this study, the ethanol extracts (AGE) and the methanol and hexane partition layers (AGEM, AGEH) of the Angelica radix were screened for their cytotoxic effects using the MTT assay on HepG2, HeLa, MCF7 and SW626 cells and for their ability to induce quinone reductase (QR) in HepG2 cells. AGEM and AGEH of the Angelica radix showed the strongest cytotoxic effects on HepG2 and HeLa cells. Cell growth was inhibited by 99.8% and 99.8% on HepG2 cells and 99.3% and 99.4% on HeLa cells, at dose of $100\;\mu\textrm{g}/ml$ of AGEM and AGEH extracts respectively. AGE and AGEH significantly induced QR activities in the HepG2 cells. The QR activities of HepG2 cells grown in the presence of AGE, AGEH, and AGEM at the concentration of $50\;\mu\textrm{g}/mL$ were 313.5, 273.3 and 133.3 nmol/min/mg protein, respectively. Therefore, based on these studies, Angelica radix may be developed into a potentially useful cancer chemopreventive agent.