• Molecular & Cellular Toxicology
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• v.3 no.4
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• pp.254-261
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• 2007

20-O-($\beta$-D-Glucopyranosyl)-20 (S)-protopanaxadiol (IH-901) is one of the major metabolites of ginsenosides from Panax ginseng, and is suggested that IH-901 has been associated with various pharmacological and physiological activities. In this study, we demonstrate that IH-901 induced anti-inflammation in HT-29 human colon adenocarcinoma cells. Our results showed that IH-901 inhibited cell proliferation of HT-29 in a time- and dose-dependent manner. We also found that IH-901 was significantly decreased expression of iNOS compared with non-treated. We observed effect of IH-901 related with inflammatory genes using by cDNA microarray. We were known that the 34 inflammatory genes such as E2F, CDK6, TNF-$\alpha$, and PKC were down-regulated. Thus, these results suggest that IH-901 may have a potential preventive factor to improving cancer induced by chronic inflammation.

• Molecular & Cellular Toxicology
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• v.3 no.4
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• pp.282-291
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• 2007

Although the etiology of schizophrenia is known to be linked with the disturbance of glutamatergic and dopaminergic neurotransmission, little is known about the relationship between gene expression and the disease process. To identify genes related to abnormalities in glutamatergic and dopaminergic function, we investigated the effects of olanzapine in the changes of mRNA levels in the animal model of schizophrenia, using a high-density DNA microarray. Olanzapine (3.0 mg/kg, i.p.) significantly reduced hyperlocomotive activities, which was induced by MK-801 (1.0 mg/kg, i.p.). We identified that the expression of 719 genes were significantly altered more than two folds in the prefrontal cortex of the rats treated with MK-801. We selected 15 genes out of them by the changes of the expression pattern in the treatment of Olanzapine and/or MK801 for the further confirmation in RT-PCR. The administration of MK-801 increased the expression of 7 genes (NOS3, Hspb1, Hspa1a, CRH, Serpine1, Igfbp6, Snf1lk) and decreased the expression of 1 gene (Aldh1a2), which was attenuated by olanzapine. One gene (Prss12) was up-regulated after olanzapine treatment although it did not show the significant changes after MK-801 treatment. These results showed that antipsychotic drug, such as olanzapine, may alter the gene expression patterns, which were accompanied by MK-801-induced psychosis. Our results also provide us high-density DNA microarray technology could be potential approaches to find the candidate molecules for the therapeutics and also for the early diagnosis of psychiatric diseases.

• Molecular & Cellular Toxicology
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• v.3 no.4
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• pp.262-266
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• 2007

ENPP2, a 125 kDa secreted lysophopholipase D which originally identified as a tumor-motogen, Autotaxin, enhances cellular locomotion, cell proliferation, angiogenesis and cell survival by generating the signal molecule lysophosphatic acid or sphingosine-1-phosphate. Previous studies have suggested that expression of Autotaxin is associated with invasive phenotype in advanced breast carcinomas. Thus, to determine whether genetic alterations of ENPP2 gene are involved in the development or progression of breast cancer, we analyzed its somatic mutation in 85 breast carcinomas by single-stranded conformational polymorphism and sequencing. Overall, six ENPP2 mutations were found (7.0%), comprising five missense and one nonsense mutation (s). To our knowledge, this is the first report on ENPP2 mutation in breast carcinoma, and the data indicate that ENPP2 is occasionally mutated in breast carcinomas, and suggest that ENPP2 mutation may contribute to the tumor development in some breast carcinomas.

• Molecular & Cellular Toxicology
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• v.3 no.4
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• pp.292-298
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• 2007

Zinc plays indispensable roles in metabolism, including cell growth, apoptosis, proliferation and differentiation. Kidneys are target organs for various regulators of mineral metabolism, and play a key role in zinc balance. To investigate the zinc uptake efficiency, we examined the zinc uptake and accumulation level in vivo and in vitro study. Plasma zinc concentration was peaked out at 1 hr after oral zinc administration. The renal zinc level was peaked out at 12 hr after oral zinc administration, and it was the highest in 40 mg/kg Zn-Asp administrated group in comparison with other groups. In addition, the m-RNA expression level of zinc transporter-1 (ZnT-1), zinc transporter-2 (ZnT-2) and high-affinity L-aspartate transporter (EAAT-3) in Zn-Asp administered group were increased compared with control groups and $ZnSO_4$ group. In order to investigate the intracellular zinc uptake mechanism, we performed the in vitro study by using human embryonic kidney cell line, HEK 293. Intracellular zinc level was peaked out at 3 hr after zinc treatment. In the same way, the mRNA expression level of ZnT-1 and EAAT-3 were increased compared with control group. This study showed that Zn-Asp is effective the zinc uptake into the kidney by increasing the zinc transporter expression.

• Molecular & Cellular Toxicology
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• v.1 no.1
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• pp.62-71
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• 2005

For toxicity model in the kidney, renal cell carcinoma (RCC) is one of the most important model to assess the structural and functional alterations. Most RCCs are sporadic, and environmental agents are suspected to play a role in the etiology of the disease. In this study, we discovered novel evidence for previously unknown gene expression patterns related to progression according to cancer stage in RCC. Four clear cell RCC tissue samples along with five corresponding patient-matched normal kidney tissue samples were obtained from patients undergoing partial or radical nephrectomy. To examine the difference of gene expression profile in clear cell RCC, radioactive cDNA microarrays were used to evaluate changes in the expression of 1,152 genes in a total. Using $^{33}P-labeled$ probes, this method provided highly sensitive gene expression profiles including drug metabolism, and cellular signaling. 29 genes were identified with expression levels that differed by more than 2.0 value of z-ratio, compared with that in control. Whereas expression of 38 genes were decreased by less than-2.0 value of z-ratio. In conclusion, this study has identified 67 gene expression alterations in clear-cell type of RCC. Most notably, genes involved in cell growth were up-regulated in stage I more than stage III whereas genes involved in signal transduction were down-regulated in which both stage I and stage III. The identified alteraions of gene expression will likely give in sight in to clear cell RCC and tumor progression.

• Molecular & Cellular Toxicology
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• v.1 no.1
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• pp.17-25
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• 2005

There are some critical drawbacks in the use of biomarkers for a global assessment of the toxicological impacts many chemicals and environmental pollutants have, primarily due to an individual biomarker's specificity for an explicit chemical or toxicant. In other words, the biomarker-based assessment methodology used to analyze toxicological effects lacks a high-throughput capability. Therefore, eco-toxicogenomics, or the study of toxicogenomics with organisms present within a given environmental locale, has recently been introduced with the advent of the so-called "-omics" era, which began with the creation of microarray technologies. Fish are comparable with humans in their toxicological responses and thus data from toxicogenomic studies performed with fish could be applied, with appropriate tools and implementation protocols, to the evaluation of environments where human or animal health is of concern. At present, there have been very active research streams for developing expression sequence tag (EST) databases (DBs) for zebra fish and rainbow trout. Even though few reports involve toxicogenomic studies with fish, a few groups have successfully fabricated and used cDNA microarrays or oligo DNA chips when studying the toxicological impacts of hypoxia or some toxicants with fish. Furthermore, it is strongly believed that this technology can also be implemented with non-model fish. With the standardization of DNA microarray technologies and ample progress in bioinformatics and proteomic technologies, data obtained from DNA microarray technologies offer not only multiple biomarker assays or an analysis of gene expression profiles, but also a means of elucidating gene networking, gene-gene relations, chemical-gene interactions, and chemical-chemical relationships. Accordingly, the ultimate target of eco-toxicogenomics should be to predict and map the pathways of stress propagation within an organism and to analyze stress networking.

• Molecular & Cellular Toxicology
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• v.4 no.3
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• pp.211-217
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• 2008

To clarify the DNA damage from reactive oxygen species, we measured the DNA damage through Fpg/Endo III FLARE (Fragment Length Analysis with Repair Enzyme) assay and real time RT-PCR. The 80 SD rats assigned to 4 dose groups exposed to cumene vapor for 90 days. With Fpg/Endo III FLARE assay in hepatocytes, we found the OTM (Olive Tail Moment) and TL (Tail Length) significantly increased in no-enzyme treated and Fpg-treated control and 8 ppm groups with 28 days exposure. In Endo III-treated 8 ppm group, significantly increased the values with 90 days exposure. With lymphocytes, it was founded the values significantly increased in no-enzyme treated 800 ppm group in 28 and 90 days. It was significantly increased in Endo III-treated 80 ppm for 28 days and 800 ppm for 90 days. From the above findings, FLARE assay was suggested as being available as a biological marker for DNA damage induced by cumene exposure in SD rats. And we used real time RT-PCR for the OGG1 mRNA expression, it had dose-dependent biologic effects in 1 day exposure, but decrease the levels of rOGG1 mRNA. Our findings provide evidence that cumene exposure may cause suppression of rOGG1 in the rat hepatocytes or lymphocytes.

• Molecular & Cellular Toxicology
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• v.4 no.3
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• pp.224-229
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• 2008

Eucommia ulmoides (Duchung) is commonly used for treatment of diabetes in Korean traditional medicine. However, the exact mechanism of its anti-diabetic effect has not yet been fully elucidated. In this study, the effect of E. ulmoides extract on glucose uptake was investigated in L6 rat skeletal muscle cells. E. ulmoides extract stimulated the activity of phosphatidylinositol (PI) 3-kinase that is a major regulatory molecule in glucose uptake pathway. Protein kinase B (PKB) and protein kinase C-${\xi}$ (PKC-${\xi}$), downstream mediators of PI 3-kinase, were also activated by E. ulmoides extract. We assessed the activity of AMP-activated protein kinase (AMPK), another regulatory molecule in glucose uptake pathway. Phosphorylation level of AMPK did not change with treatment of E. ulmoides extract. Phosphorylations of p38 mitogen activated protein kinase (p38 MAPK) and acetyl-CoA carboxylase (ACC), downstream mediators of AMPK, were not significantly different. Taken together, our results suggest that E. ulmoides may stimulate glucose uptake through PI 3-kinase but not AMPK in L6 skeletal muscle cells.

• Molecular & Cellular Toxicology
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• v.4 no.3
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• pp.246-252
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• 2008

Tumor tissue is usually contaminated by normal tissue components, which reduces the sensitivity of analysis for exploring genetic alterations. Although microdissection has been adopted to minimize the contamination of tumor DNA with normal cell components, there is a concern over the amount of microdissected DNA not enough to be applied to array-CGH reaction. To amplify the extracted DNA, several whole genome amplification (WGA) methods have been developed, but objective comparison of the array-CGH outputs using different types of WGA methods is still scarce. In this study, we compared the performance of non-amplified microdissected DNA and DNA amplified in 2 WGA methods such as degenerative oligonucleotide primed (DOP)-PCR, and multiple strand displacement amplification (MDA) using Phi 29 DNA polymerase. Genomic DNA was also used to make a comparison. We applied those 4 DNAs to whole genome BAC array to compare the false positive detection rate (FPDR) and sensitivity in detecting copy number alterations under the same hybridization condition. As a result microdissected DNA method showed the lowest FPDR and the highest sensitivity. Among WGA methods, DOP-PCR amplified DNA showed better sensitivity but similar FPDR to MDA-amplified method. These results demonstrate the advantage and applicability of microdissection for array-CGH analysis, and provide useful information for choosing amplification methods to study copy number alterations, especially based on precancerous and microscopically invaded lesions.

• Molecular & Cellular Toxicology
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• v.4 no.3
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• pp.260-266
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• 2008

Recently, there has been scientific discussion on the utility of -omics techniques such as genomics, proteomics, and metabolomics within toxicological research and mechanism-based risk assessment. Toxicogenomics is a novel approach integrating the expression analysis of genes (genomic) or proteins (proteomic) with traditional toxicological methods. Since 1999, the toxicogenomic approach has been extensively applied for regulatory purposes in order to understand the potential toxic mechanisms that result from chemical compound exposures. Therefore, this article's purpose was to consider the utility of toxicogenomic profiles for improved risk assessment, explore the current limitations in applying toxicogenomics to regulation, and finally, to rationalize possible avenues to resolve some of the major challenges. Based on many recent works, the significant impact toxicogenomic techniques would have on human health risk assessment is better identification of toxicity pathways or mode-of-actions (MOAs). In addition, the application of toxicogenomics in risk assessment and regulation has proven to be cost effective in terms of screening unknown toxicants prior to more extensive and costly experimental evaluation. However, to maximize the utility of these techniques in regulation, researchers and regulators must resolve many parallel challenges with regard to data collection, integration, and interpretation. Furthermore, standard guidance has to be prepared for researchers and assessors on the scientifically appropriate use of toxicogenomic profiles in risk assessment. The National Institute of Toxicological Research (NITR) looks forward to an ongoing role as leader in addressing the challenges associated with the scientifically sound use of toxicogenomics data in risk assessment.