• Biomedical Science Letters
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• v.24 no.1
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• pp.50-54
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• 2018

N-nitroso-N-methylurea (NMU) and N-nitroso-N-ethylurea (NEU), direct alkylating chemical mutagens and carcinogens, are shown to be the upregulators of cellular $NF-{\kappa}B$, regulating various genes that mediate tumorigenesis and carcinogenesis. Nitric oxide (NO), a toxic reactive radical gas, has been known to induce programmed cell death or apoptosis in various cells. Therefore, the assessment of NO production was examined to elucidate the possible contribution of NO release to the chemical carcinogenic potency of NMU and NEU in human skin cells. NMU and NEU did not alter the NO production, but they caused a significant downregulation of the NO generation on lipopolysaccharide (LPS)-induced NO production at concentrations ranging from $2{\sim}5{\mu}M$. The degree of downregulation of NO by NMU and NEU decreased up to 15% and 20%, respectively, compared to the control. These results demonstrate that the LPS-inducible keratinocytes NO synthase is involved in modulating carcinogenic potency by NMU and NEU, and the regulation of the cellular $NF-{\kappa}B$ activity by NMU and NEU is negatively correlated with the level of LPS-induced NO production in human skin cells. The findings of this study suggest the hypothesis that NMU and NEU-induced carcinogenesis may be associated with the downregulation of NO production, and the inducible NO may play an important role in NMU and NEU-induced carcinogenicity in human epidermal keratinocytes.

• Korean Journal of Plant Resources
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• v.19 no.2
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• pp.374-380
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• 2006

With the aim of inducing mutation in fern Cyrtomium caryoptideum var. coreanum, rhizome segments of In vitro-grown cultures were treated with chemical mutagens such as EMS, NMU and colchicine. Based on regeneration ratios, sensitivities for each treatments were assessed and also optimum treatment condition of each mutagens was explored. Optimum concentration for EMS treatment was considered to be 20 to 50mM and for NMU 5 to 10mM. NMU was found to be more effective in inducing chlorophyll and morphological variations than EMS. The RAPD were performed to check the genetic modification of phenotypical variants. As a result, polymorphic DNA band patterns between wild type and variants were observed by two 10-mer primers.

• Environmental Mutagens and Carcinogens
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• v.9 no.1
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• pp.1-12
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• 1989

To study the selective organospecific carcinogenesis by the specific chemical carcinogens, the breast cancer induction model by oral administration of 7, 12-dimethylbenzanthracene (DMBA) or by intravenous injection of N-methylni-trosourea (NMU) on female rats was analyzed. In the present experiment, we compared the effexts of ages on the chemical mammary carcinogenesis by studying the metabolic system of the carcinogenic activation, detoxification or DNA damage and repair. The breast tumor incidence was significantly higher in the young rats of 50 days old than in those of one year old rats. As an index of organospecific DNA damage or repair, the in vivo covalent binding index(CBI) of the specific organs by the specific chemical carcinogens was monitored. And for the analysis of carcinogenic activation, the quantity of cytochrome P450`s was determined with the respective type-specific monoclonal antibody, while the detoxication capacity was deduced by the activity monitoring of glutathione S-transferase (GST) and peroxidase. The skin tissues of the mammary region had the highest CBI with both of DMBA and NMU at 50 days of age. And there were contrasting differences in the contents of carcinogenic activation and detoxication system: that is, the content of T.C.D.D.-inducible cytochrome P450 was high, while the activities of GST and peroxidase was low in the mammary skin tissues at tumor prevalent age. These results led us to conclude that the molecular organospecific carcinogenesis, as illustrated with mammary carcinoge-nesis by DMBA and NMU, is operated probably through the differential capacity of the target tissues in the high carcinogenic activation, low detoxication and the low DNA repair function.

• Korean Journal of Plant Resources
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• v.19 no.2
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• pp.348-354
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• 2006

Homogenized prothallus of 6 species (Cyrtomium falcatum, Cyrtomium caryoptideum var. coreanum, Dryopteris varia, Asplenium incisum, Camptosous sibiricus and Phyllitis scolopendrium) were treated with gamma radiation or by chemical mutagenesis with EMS, NMU, $NaN_3$ and colchicine to assess their sensitivities for each treatments and also with the aim of inducing mutations. Generally, decrease of proliferation ratio was dose-dependent and time-dependent. Based on proliferation ratio, optimum dose of gamma irradiation was $5{\sim}10krad$ except in D. varia with 20krad. Optimum condition of EMS treatment was considered as 50mM for 3h and for NMU as $5{\sim}10mM\;for\;1{\sim}3h$. Optimum condition of $NaN_3$ treatment was considered as $0.5{\sim}1mM\;for\;1{\sim}3h$. For colchicine, there were significant differences between species as to the proliferation ratios of prothallus for each treatment.

• Journal of Oriental Neuropsychiatry
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• v.20 no.1
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• pp.147-164
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• 2009

Objectives : We investigated the effects of Sopungsungi-won(Shu!engshunqiyuan) (SSEx1, SSEx2) to treat the metabolic syndrome by the molecular mechanism of regulation of PPAR and modulation of mitochondrial MCAD, VLCAD mRNA expression. Methods : Mouse NMu2Li liver cells and C2C12 skeletal muscle myogenic progenital cells were transiently transfected with expression plasmids for PPAR(PPAR${\alpha}$, PPAR${\delta}$), a luciferase reporter gene construct containing 3 copies of the PPRE from the rat acyl-CoA oxidase gene and ${\beta}$-galactosidase gene. Cells were treated with several concentrated kinds of SSEx1, SSEx2 at the initial time of culture and analyzed PPAR${\alpha}$, PPAR${\delta}$ reporter gene activity using spectrophotometer (405 nm). Total RNA was extracted from SSEx1, SSEx2 and measured mRNA levels of mitochondrial MCAD, VLCAD. Representative RT-PCR bands are shown. Results : 1. SSEx1 increased the expression of PPAR${\alpha}$ reporter gene activities at 0.1 ${\mu}$g/ml (p${\mu}$g/ml (p<0.05), SSEx2 at 0.1 ${\mu}$g/ml (p${\mu}$g/ml (p<0.05) significantly in NMu2Li liver cell lines. 2. SSEx1 increased the expression of PPAR${\alpha}$ reporter gene activities at 1 ${\mu}$g/ml (p${\mu}$g/ml (p${\alpha}$ reporter gene activities in C2C12 skeletal muscle cells. 4. SSEx1 increased the modulation of mitochondrial MCAD mRNA expression (p<0.05) significantly in NMu2Li liver cell lines. 5. SSEx1, SSEx2 both increased the modulation of mitochondrial MCAD mRNA expression (p<0.05) significantly in C2C12 skeletal muscle cells. Conclusions : These results show the SSEx1, SSEx2 can be used as therapeutic agent for metabolic syndrome and it's molecular mechanisms of PPAR more contribute to the activation of PPAR${\alpha}$ then PPAR${\delta}$ reporter gene activities and it's total RNA more contribute to the modulation of mitochondrial MCAD then VLCAD mRNA expression.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.16
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• pp.6721-6726
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• 2014

Background: The aim of this preliminary study was to address variations of responses observed with different starting tumor sizes of 10 and 15 mm, and the effects of different doses of tamoxifen (TAM) on experimental rat mammary tumors. Materials and Methods: Thirty-five inbred female Sprague Dawley rats aged 43 days were administered with three weekly doses of N-methyl-N-nitrosourea (NMU) intraperitoneally (ip) at 50 mg/kg body weight. Animals were randomized (beginning from 10 mm tumor size) into four TAM-treated (50, 100, 200 and $500{\mu}g/day$) groups of six animals each, and another group (n=6) treated with TAM $100{\mu}g/day$ at starting tumour size of 15 mm. The animals were treated by oral gavage daily for 8 weeks before sacrifice. Results: Serum urea and creatinine, and overall physical tumor burden were significantly modulated in animals treated with variable doses of TAM compared to the untreated controls (n=5). Final body weight and tumor number were significantly different in the 10 mm-treated animals compared to those treated at 15 mm. There were no significant differences in histopathological features among all the groups. Conclusions: Our findings suggest the importance of standardizing tumour size and drug doses before initiation of treatment, particularly in the direct comparison of basic end-tumour physical parameters.

• The Korea Journal of Herbology
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• v.27 no.2
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• pp.53-59
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• 2012

Objectives : This study was undertaken to investigate the effects of the GGEx18 ethyl acetate fraction (EF) on lipid accumulation and gene expression of fatty acid-oxidizing enzymes using 3T3-L1 adipocytes, C2C12 skeletal muscle cells, and NMu2Li liver cells. Methods : PPAR${\alpha}$, AMPK and UCPs transactivation was examined in NMu2Li hepatocytes, C2C12 myocytes, and 3T3-L1 preadipocytes using transient transfection assays. Results : 1. Compared with control, EF significantly increased the mRNA expression of VLCAD in 3T3-L1 adipocytes. 2. Compared with control, EF (0.1 ${\mu}g/ml$) significantly inhibited lipid accumulation in 3T3-L1 adipocytes. 3. EF significantly increased the mRNA expression of AMPK${\alpha}$1, AMPK${\alpha}$2 and PPAR${\alpha}$ in C2C12 skeletal muscle cells compared with control. 4. EF significantly increased the mRNA expression of genes involved in fatty acid ${\beta}$-oxidation, such as thiolase, MCAD, and CPT-1 in C2C12 skeletal muscle cells compared with control. 5. EF significantly increased the mRNA expression of UCP2 involved in energy expenditure in C2C12 skeletal muscle cells compared with control. 6. Compared with control, EF (10 ${\mu}g/ml$) significantly inhibited lipid accumulation in C2C12 skeletal muscle cells. 7. EF (10 ${\mu}g/ml$) significantly increased the mRNA expression of ACOX, HD, VLCAD and MCAD in NMu2Li liver cells compared with control. Conclusions : These results suggest that EF may prevent obesity by increasing the mRNA expression of mitochondrial fatty acid ${\beta}$-oxidizing enzymes in 3T3-L1 adipocytes, by not only regulating the fatty acid oxidation through activation of AMPK and PPAR${\alpha}$, but also increasing the UCP2 mRNA expression in C2C12 skeletal muscle cells, and by stimulating the mRNA expression of fatty acid-oxidizing enzymes in NMu2Li liver cells.

• Journal of Radiation Industry
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• v.6 no.2
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• pp.189-197
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• 2012

This study was carried out to develop the improved useful mutants for yield or composition of stevia plants using the gamma ray or chemical mutagens treatments. The seeds of stevia 'Suwon No. 11' were irradiated up to 400 Gy of gamma ray. Chemical mutagens were treated on the seeds of the 'Suwon No. 11' using 0.07% colchicine, 10 mM sodium azide, or 10 mM NMU for various durations. The germination rate, and shoot and root growth of seedling were estimated at 30 days after gamma ray irradiation or chemical mutagen treatment, and the plant height, the number of branches, and leaf length and width were examined at 3 months after mutagenesis treatments. In the case of gamma ray treatments, the germination rate and early-stage growth were decreased as the increase of radiation dose, and the 50% lethal dose was found to be 200 Gy. the plant height was decreased as the increase of radiation dose, while the number of branches per plant and leaf length were increased. Leaf shape was modified to the relatively longer one compared to the control, which was identified more apparently at the treatments of higher than 150 Gy. In the treatment of chemical mutagens, the rate of germination and survival were decreased as the increase of incubation time. The 50% lethal dose for germination rate were identified as the conditions of the 15 hours incubation in 0.07% colchicine, the 4 hrs in 10 mM sodium azide, and the 2 hrs in 10 mM NMU, in the three chemical mutagens treatments. Chemical mutagens had no influence on shoot growth, while root growth was increased, especially as the incubation time was extended. The highest root growth occurred in the NMU treatment at 6 hrs incubation time. The plant height was decreased as the increase of incubation time in the chemical mutagens treatments. Among the chemical mutagens, NMU was the most effective to induce the mutants with long-shaped or the least lobed leaves.

• Journal of Life Science
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• v.8 no.1
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• pp.102-108
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• 1998

The nascent from of glycosylphosphatidylinositol (GPI)-anchored proteins possesses both amino and carboxy terminal hydrophobic signal sequences to direct processing in the endoplasmic reticulum (ER). Following cleavage of the amino-terminal signal peptide, the carboxy-terminal peptide is processed. Previously, mouse lymphocyte NDA: agrinine ADP-ribosyltransferase (Yac-1) was cloned and the deduced amino acid sequence of the Yac-1 transferase contained hydrophobic amino and carboxy termini, consistent with known signal sequences of GPI-anchored proteins. This tranferase was present on the surface of NMU (rat mammary adenocarcinoma) cells transfected with the wildtype cDNA and was released with phosphatidylinositol-specific phosphilpase C. Expression of the mutant protein, lacking the carboxy terminal hydrophobic sequence, resulted in the peoduction of soluble, secreted from of the transferase. This result shows that carboxy terminal sequence is important for GPI-attachment.

• The Korea Journal of Herbology
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• v.28 no.2
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• pp.39-44
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• 2013

Objectives : Gambigyeongsinhwan 16 (GGEx16), gambigyeongsinhwan 18 (GGEx18) and gambitongseong capsule are shown to be involved in the regulation of obesity. Therefore, the aim of this study was to compare the reporter activity of anti-obesity genes such as peroxisome proliferator-activated receptor ${\alpha}$ ($PPAR{\alpha}$) and $PPAR{\delta}$ by GGEx16, GGEx18 and gambitongseong capsule. Methods : After NMu2Li liver cells, C2C12 skeletal muscle cells and 3T3-L1 preadipocytes were treated with GGEx16 (1 ${\mu}g/ml$), GGEx18 (1 ${\mu}g/ml$) and different concentrations of gambitongseong capsule, the transactivation of $PPAR{\alpha}$ and $PPAR{\delta}$ was measured by a luciferase reporter gene assay. Results : $PPAR{\alpha}$ reporter gene activity in NMu2Li liver cells and 3T3-L1 preadipocytes was significantly increased by GGEx16, GGEx18 and gambitongseong capsule compared with control, whereas $PPAR{\alpha}$ reporter gene activity in C2C12 skeletal muscle cells was significantly increased by GGEx18 only compared with control. Similarly, $PPAR{\delta}$ reporter gene activity in 3T3-L1 preadipocytes was also significantly increased by GGEx18 compared with control. $PPAR{\delta}$ reporter gene activity in C2C12 skeletal muscle cells was significantly increased by GGEx16 and GGEx18 compared with control although $PPAR{\delta}$ reporter gene activity in NMu2Li liver cells was not changed by these three formulas. Conclusions : These results suggest that all three formulas have the ability to stimulate $PPAR{\alpha}$ and $PPAR{\delta}$ transactivation in animal cell lines with high metabolic rates. In particular, this effects were most prominent in GGEx18-treated cells. In addition, it is likely that GGEx18 may be used as an effective anti-obesity composition.