Effects of CYP1A2$^*$1C and CYP1A2$^*$1F Genotypes on the Activity and Inducibility of CYP1A2 Determined by Urinary Caffeine Metabolite Ratio in Koreans

Shin, Mi-Kyung,Yi, Hyeon-Gyu,Kwon, Yong-Hyun,Lee, Sung-Keun,Lim, Woo-Sung,Park, Chang-Shin,Kang, Ju-Hee The Korean Society of Toxicogenomics and Toxicopro 2007 Molecular & cellular toxicology Vol.3 No.4

The effects of common variants of CYP1A2 gene (CYP1A2$^*$1C and CYP1A2$^*$1F) on the CYP1A2 activity and inducibility were controversial. The aim of the present study is to investigate the effects of CYP1A2$^*$1C and CYP1A2$^*$1F on the activity of CYP1A2 determined by urinary caffeine metabolite ratio in Koreans. As might be expected, there was large inter-individual variation (16-folds) of CYP1A2 activity ranged from 2.41 to 39.58. The mean CYP1A2 activity of smokers was significantly higher than that of non-smokers. The frequencies of CYP1A2$^*$1C (-3858A) and $^*$1F (-164A) alleles were 0.219 and 0.646, respectively. The effect of CYP1A2$^*$1C on the CYP1A2 activity was not significant. However, the CYP1A2 activity of subjects with AA genotype for CYP1A2$^*$1F allele was significantly lower than that of non-AA genotypes (CC, or CA). Interestingly, the significant effect of CYP1A2$^*$1F allele on CYP1A2 activity was not observed in nonsmokers. Our results suggest that CYP1A2$^*$1F allele rather than CYP1A2$^*$1C allele significantly influences on the inducibility of CYP1A2 in Koreans. Owing to small sample size of our study, further studies should be conducted to reveal the inter-ethnic difference or the gene-environmental interaction.

Eco-toxicogenomics Research with Fish

Park, Kyeong-Seo,Kim, Han-Na,Gu, Man-Bock The Korean Society of Toxicogenomics and Toxicopro 2005 Molecular & cellular toxicology Vol.1 No.1

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.

Mercury Level in Hair of Primary School Children in Korea and China

Park, Hee-Jin,Kim, Dae-Seon,Moon, Jeong-Suk,Yang, Won-Ho,Son, Bu-Soon The Korean Society of Toxicogenomics and Toxicopro 2008 Molecular & cellular toxicology Vol.4 No.3

Exposure to mercury was assessed in 125 Korean (Gwangju and Busan) and 373 Chinese primary school students (Xinguang village, Goumen town) using hair mercury analysis from November 2006 to September 2007. The geometric mean concentration of mercury was higher among Korean children with recording 0.73 ${\mu}g$/g, compared to Chinese children of 0.12 ${\mu}g$/g, which indicated statistically difference (P<0.01). The mean concentration of Korean children living near incineration facilities was higher by recording 0.76 ${\mu}g$/g while the average concentration of their counterpart in Korea reached 0.69 ${\mu}g$/g. In case of Chinese children, those who are living near power plants showed higher level with posting 0.16 ${\mu}g$/g while the others recorded 0.10 ${\mu}g$/g (P<0.01). Intake of fish was found to be related to hair mercury level. In case of Korean children, those with high fish intake recorded 0.79 ${\mu}g$/g in terms of the geometric mean concentration while the others with low fish intake posted 0.61 ${\mu}g$/g. Among Chinese children, those who often eat fish recorded 0.13 ${\mu}g$/g compared to the others with low fish intake of 0.11 ${\mu}g$/g. On the other hand, amalgam dental fillings have limited influence on mean hair mercury level. As for vaccination, within a month of vaccination, the geometric mean concentration of Korean children reached 0.76 ${\mu}g$/g, and in case of 15 days after injection, the level was 1.20 ${\mu}g$/g. In China, the level of children at one month after receiving injection stood at 0.15 ${\mu}g$/g while the level within 15 days was 0.13 ${\mu}g$/g. Multiple regression analysis showed that BMI, passive smoking, and fish consumption are closely related to hair mercury level among the Korean subjects. In China, hair mercury level was affected by age, location, passive smoking, fish consumption, and vaccination. Explanatory power was 21.6% with $R^2$=0.216.

Application of Toxicogenomic Technology for the Improvement of Risk Assessment

Hwang, Myung-Sil,Yoon, Eun-Kyung,Kim, Ja-Young,Son, Bo-Kyung,Jang, Dong-Deuk,Yoo, Tae-Moo The Korean Society of Toxicogenomics and Toxicopro 2008 Molecular & cellular toxicology Vol.4 No.3

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.

SOP (Search of Omics Pathway): A Web-based Tool for Visualization of KEGG Pathway Diagrams of Omics Data

Kim, Jun-Sub,Yeom, Hye-Jung,Kim, Seung-Jun,Kim, Ji-Hoon,Park, Hye-Won,Oh, Moon-Ju,Hwang, Seung-Yong The Korean Society of Toxicogenomics and Toxicopro 2007 Molecular & cellular toxicology Vol.3 No.3

With the help of a development and popularization of microarray technology that enable to us to simultaneously investigate the expression pattern of thousands of genes, the toxicogenomics experimenters can interpret the genome-scale interaction between genes exposed in toxicant or toxicant-related environment. The ultimate and primary goal of toxicogenomics identifies functional context among the group of genes that are differentially or similarly coexpressed under the specific toxic substance. On the other side, public reference databases with transcriptom, proteom, and biological pathway information are needed for the analysis of these complex omics data. However, due to the heterogeneous and independent nature of these databases, it is hard to individually analyze a large omics annotations and their pathway information. Fortunately, several web sites of the public database provide information linked to other. Nevertheless it involves not only approriate information but also unnecessary information to users. Therefore, the systematically integrated database that is suitable to a demand of experimenters is needed. For these reasons, we propose SOP (Search of Omics Pathway) database system which is constructed as the integrated biological database converting heterogeneous feature of public databases into combined feature. In addition, SOP offers user-friendly web interfaces which enable users to submit gene queries for biological interpretation of gene lists derived from omics experiments. Outputs of SOP web interface are supported as the omics annotation table and the visualized pathway maps of KEGG PATHWAY database. We believe that SOP will appear as a helpful tool to perform biological interpretation of genes or proteins traced to omics experiments, lead to new discoveries from their pathway analysis, and design new hypothesis for a next toxicogenomics experiments.

Promising Next Generation Technology in Toxicology-Toxicogenomics

Ryu, Jae-Chun,Kim, Meyoung-Kon,Cho, Man-Ho,Chun, Tae-Hoon The Korean Society of Toxicogenomics and Toxicopro 2005 Molecular & cellular toxicology Vol.1 No.1

Toxicology is a multidisciplinary field, and an important science that impacts both environmental health regulation and the development and practice of medicine. The rapid progress in cellular and molecular biology, like many other branches of biomedical research, toxicology is now experiencing a renaissance fueled by the application of "omic" technologies to gain a better understanding of the biological basis of toxicology of drugs and other environmental factors. In this review on current progress on toxicology, the future perspective, concept, approaches and applications of toxicogenomics as next generation promising technology in toxicology field will be described.

Toxicogenomics Study on ${\alpha}-Naphthylisothiocyanate\;(ANIT)$ Induced Hepatotoxictiy in Mice

Hwang, Ji-Yoon,Lim, Jung-Sun,Jeong, Sun-Young,Park, Han-Jin,Cho, Jae-Woo,Yoon, Seok-Joo The Korean Society of Toxicogenomics and Toxicopro 2006 Molecular & cellular toxicology Vol.2 No.1

[ ${\alpha}-Naphthylisothiocyanate$ ] (ANIT) induces intrahepatic cholestasis, involving damage to biliary epitheial cells. This study investigates hepatic gene expression and histopathological alterations in response to ANIT treatment in order to elucidate early time response of ANIT-induced hepatotoxicity. ANIT was treated with single dose (3, 6, and 60 mg/kg) in corn oil by oral gavage. Serum biochemical and histopathological observation were performed for evaluation of hepatotoxicity level. Affymetrix oligo DNA chips were used for gene expression profile by ANIT-induced hetpatoxicity. Hepatic enzyme levels (ALT, AST, and ALP) were increased in 24 hr high dose group. In microscopic observations, moderate hepatocellular necrosis, were confirmed 24 hr high dose groups. We found that gene expression patterns were dependent on time and dose. Our selected genes were related inflammation and immunomodulation. In this study, ANIT-induced hepatotoxicity was involved in acute phase responses and provides evidence for role of neutrophil could be mechanism associated with ANIT-mediated hepatotoxicity.

Toxicogenomic Effect of Liver-toxic Environmental Chemicals in Human Hepatoma Cell Line

Kim, Seung-Jun,Park, Hye-Won,Yu, So-Yeon,Kim, Jun-Sub,Ha, Jung-Mi,Youn, Jong-Pil,An, Yu-Ri,Oh, Moon-Ju,Kim, Youn-Jung,Ryu, Jae-Chun,Hwang, Seung-Yong The Korean Society of Toxicogenomics and Toxicopro 2009 Molecular & cellular toxicology Vol.5 No.4

Some environmental chemicals have been shown to cause liver-toxicity as the result of bioaccumulation. Particularly, fungicides have been shown to cause varying degrees of hepatictoxicity and to disrupt steroid hormone homeostasis in in vivo models. The principal objective of this study was to evaluate the liver-toxic responses of environmental chemicals-in this case selected fungicides and parasiticides-in order to determine whether or not this agent differentially affected its toxicogenomic activities in hepatic tumor cell lines. To determine the gene expression profiles of 3 fungicides (triadimefon, myclobutanil, vinclozolin) and 1 parasiticide (dibutyl phthalate), we utilized a modified HazChem human array V2. Additionally, in order to observe the differential alterations in its time-dependent activities, we conducted two time (3 hr, 48 hr) exposures to the respective IC20 values of four chemicals. As a result, we analyzed the expression profiles of a total of 1638 genes, and we identified 70 positive significant genes and 144 negative significant genes using four fungicidic and parasiticidic chemicals, using SAM (Significant Analysis of Microarray) methods (q-value<0.5%). These genes were analyzed and identified as being related to apoptosis, stress responses, germ cell development, cofactor metabolism, and lipid metabolism in GO functions and pathways. Additionally, we found 120 genes among those time-dependently differentially expressed genes, using 1-way ANOVA (P-value<0.05). These genes were related to protein metabolism, stress responses, and positive regulation of apoptosis. These data support the conclusion that the four tested chemicals have common toxicogenomic effects and evidence respectively differential expression profiles according to exposure time.

Toxicogenomic Study to Identify Potential New Mechanistic Markers on Direct-Acting Mutagens in Human Hepatocytes (THLE-3)

Kim, Youn-Jung,Song, Mi-Kyung,Song, Mee,Ryu, Jae-Chun The Korean Society of Toxicogenomics and Toxicopro 2007 Molecular & cellular toxicology Vol.3 No.4

Exposure to DNA-damaging agents can elicit a variety of stress-related responses that may alter the expression of genes associated with numerous biological pathways. We used 19 k whole human genome chip to detect gene expression profiles and potential signature genes in human normal hepatocytes (THLE-3) by treatment of five direct acting mutagens, furylfuramide (AF-2), N-nitroso-N-methylurea (MNU), methylmethanesulfonate (MMS), 4-nitroquinoline-N-oxide (4-NQO) and 2-nitrofluorene (2NF) of the $IC_{20}$ concentration for 3 h. Fifty one up-regulated common genes and 45 down-regulated common genes above 1.5-fold by five direct-acting mutagens were identified by clustering analysis. Many of these changed genes have some association with apoptosis, control of cell cycle, regulation of transcription and signal transduction. Genes related to these functions, as TP73L, E2F5, MST016, SOX5, MAFB, LIF, SII3, TFIIS, EMR1, CYTL1, CX3CR1 and RHOH are up-regulated. Down-regulated genes are ALOX15B, xs155, IFITM1, BATF, VAV2, CD79A, DCDC2, TNFSF8 and KOX8. We suggest that gene expression profiling on mutagens by toxicogenomic analysis affords promising opportunities to reveal potential new mechanistic markers of genotoxicity.

Gene Expression Profiling of Genotoxicity Induced by MNNG in TK6 Cell

Suh, Soo-Kyung,Kim, Tae-Gyun,Kim, Hyun-Ju,Koo, Ye-Mo,Lee, Woo-Sun,Jung, Ki-Kyung,Jeong, Youn-Kyoung,Kang, Jin-Seok,Kim, Joo-Hwan,Lee, Eun-Mi,Park, Sue-Nie,Kim, Seung-Hee,Jung, Hai-Kwan The Korean Society of Toxicogenomics and Toxicopro 2007 Molecular & cellular toxicology Vol.3 No.2

Genotoxic stress triggers a variety of biological responses including the transcriptional activation of genes regulating DNA repair, cell survival and cell death. In this study, we investigated to examine gene expression profiles and genotoxic response in TK6 cells treated with DNA damaging agents MNNG (N-methyl-N'-nitrosoguanidine) and hydrogen peroxide $(H_2O_2)$. We extracted total RNA in three independent experiments and hybridized cRNA probes with oligo DNA chip (Applied Biosystems Human Genome Survey Microarray). We analyzed raw signal data with R program and AVADIS software and identified a number of deregulated genes with more than 1.5 log-scale fold change and statistical significancy. We indentified 14 genes including G protein alpha 12 showing deregulation by MNNG. The deregulated genes by MNNG represent the biological pathway regarding MAP kinase signaling pathway. Hydrogen peroxide altered 188 genes including sulfiredoxins. These results show that MNNG and $H_2O_2$ have both uniquely regulated genes that provide the potential to serve as biomarkers of exposure to DNA damaging agents.