Cancer Research Meeting Calendar  Frontiers in Basic Cancer Research
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Cancer Research Clinical Cancer Research
Cancer Epidemiology Biomarkers & Prevention Molecular Cancer Therapeutics
Molecular Cancer Research Cancer Prevention Research
Cancer Prevention Journals Portal Cancer Reviews Online
Annual Meeting Education Book Meeting Abstracts Online

This Article
Right arrow Abstract Freely available
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Thimmulappa, R. K.
Right arrow Articles by Biswal, S.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Thimmulappa, R. K.
Right arrow Articles by Biswal, S.
[Cancer Research 62, 5196-5203, September 15, 2002]
© 2002 American Association for Cancer Research


Carcinogenesis

Identification of Nrf2-regulated Genes Induced by the Chemopreventive Agent Sulforaphane by Oligonucleotide Microarray1

Rajesh K. Thimmulappa, Kim H. Mai, Sorachai Srisuma, Thomas W. Kensler, Masayuki Yamamoto and Shyam Biswal2

Department of Environmental Health Sciences, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland 21205-2179 [R. K. T., K. H. M., S. S., T. W. K., S. B.], and Center for Tsukuba Advanced Research Alliance and Institute of Basic Medical Sciences, University of Tsukuba, Tsukuba, 305-8577 Japan [M. Y.]


    ABSTRACT
 Top
 ABSTRACT
 INTRODUCTION
 MATERIALS AND METHODS
 RESULTS
 DISCUSSION
 REFERENCES
 
Electrophiles formed during metabolic activation of chemical carcinogens and reactive oxygen species generated from endogenous and exogenous sources play a significant role in carcinogenesis. Cancer chemoprevention by induction of phase 2 proteins to counteract the insults of these reactive intermediates has gained considerable attention. Nuclear factor E2 p45-related factor 2 (Nrf2), a bZIP transcription factor, plays a central role in the regulation (basal and or inducible expression) of phase 2 genes by binding to the "antioxidant response element" in their promoters. Identification of novel Nrf2-regulated genes is likely to provide insight into cellular defense systems against the toxicities of electrophiles and oxidants and may define effective targets for achieving cancer chemoprevention. Sulforaphane is a promising chemopreventive agent that exerts its effect by strong induction of phase 2 enzymes via activation of Nrf2. In the present study, a transcriptional profile of small intestine of wild-type (nrf2 +/+) and knock out (nrf2 -/-) mice treated with vehicle or sulforaphane (9 µmol/day for 1 week, p.o.) was generated using the Murine Genome U74Av2 oligonucleotide array (representing ~6000 well-characterized genes and nearly 6000 expressed sequence tags). Comparative analysis of gene expression changes between different treatment groups of wild-type and nrf2-deficient mice facilitated identification of numerous genes regulated by Nrf2 including previously reported Nrf2-regulated genes such as NAD(P)H:quinone reductase (NQO1), glutathione S-transferase (GST), {gamma}-glutamylcysteine synthetase (GCS), UDP-glucuronosyltransferases (UGT),epoxide hydrolase, as well as a number of new genes. Also identified were genes encoding for cellular NADPH regenerating enzymes (glucose 6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase, and malic enzyme), various xenobiotic metabolizing enzymes, antioxidants (glutathione peroxidase, glutathione reductase, ferritin, and haptaglobin), and biosynthetic enzymes of the glutathione and glucuronidation conjugation pathways. The data were validated by Northern blot analysis and enzyme assays of selected genes. This investigation expands the horizon of Nrf2-regulated genes, highlights the cross-talk between various metabolic pathways, and divulges the pivotal role played by Nrf2 in regulating cellular defenses against carcinogens and other toxins.


    INTRODUCTION
 Top
 ABSTRACT
 INTRODUCTION
 MATERIALS AND METHODS
 RESULTS
 DISCUSSION
 REFERENCES
 
There is considerable epidemiological evidence suggesting an association of consumption of fruits and vegetables with reduced incidence of cancer, especially in the gastrointestinal tract (1) . Induction of phase 2 enzymes by phytochemicals represents an important mechanism for achieving protection against cancer (2) . Although phase 2 enzymes have been traditionally recognized as those catalyzing the conjugation of endogenous ligands, glutathione and glucuronic acid, to endo- and xenobiotic substrates, this classification is expanding to include proteins that catalyze a wide variety of reactions that confer cytoprotection against the toxicity of electrophiles and reactive oxygen species (3) . The growing list of phase 2 proteins includes NAD(P)H:quinone reductase (NQO1), epoxide hydrolase, dihydrodiol dehydrogenase, {gamma}-GCS,3 heme oxygenase-1, leukotriene B4 dehydrogenase, aflatoxin B1 dehydrogenase, and ferritin (3) . These proteins, which enhance resistance to different toxicants, are regulated by a common element (5'-A/G TGA C/T NNN GC A/G-3') in their promoter region that is termed the ARE (4) . The mechanisms that regulate the expression of phase 2 genes through the ARE are the subject of intensive investigation (5) .

It has been demonstrated clearly that Nrf2, a bZIP transcription factor, translocates into the nucleus and binds to the ARE in conjugation with small Maf proteins after activation by chemopreventive agents and that Nrf2 plays a central role in the constitutive and inducible expression of several phase 2 proteins (6, 7, 8, 9, 10, 11) . Higher sensitivity of nrf2-deficient mice to liver damage by acetaminophen (12) , pulmonary injury by butylated hydroxytoluene (13) , increased DNA adducts in lungs after exposure to diesel exhaust (14) , and gastric tumors by benzo(a)pyrene (7) have been attributed to decreased basal expression of phase 2 enzymes in various organs (8 , 10 , 15) . The induction of several phase 2 genes (e.g., GST and NQO1) by butylated hydroxyanisole, oltipraz, and sulforaphane is also dependent on Nrf2 (7 , 10) . Collectively, these studies clearly indicate the pivotal role of this transcription factor in the regulation of phase 2 proteins and, thus, chemoprevention against xenobiotic toxicities.

Molecular epidemiological studies have indicated that consumption of dietary isothiocyanates are effective in decreasing the relative risk of colorectal cancer (16) and lung cancer (17 , 18) . Among the isothiocyanates, sulforaphane (R-1-isothiocyanato-4-methylsulfinylbutane) is the most potent inducer of phase 2 proteins (19, 20, 21) and functions to activate Nrf2 (10 , 11) . Sulforaphane effectively reduces colonic aberrant crypt foci formation in carcinogen-treated rats (22) . Identification of cytoprotective genes, which are directly or indirectly dependent on Nrf2 for transcriptional activation in response to promising chemopreventive agents such as sulforaphane, will facilitate the understanding of molecular downstream effectors of chemoprevention. By feeding sulforaphane p.o. to wild type and nrf2-deficient mice, we have identified several genes in a target organ, the small intestine, using oligonucleotide arrays that are dependent on Nrf2 for their basal and/or inducible expression. This study expands the horizon of Nrf2-regulated protective proteins and identifies novel downstream mediators for chemoprevention by sulforaphane and, presumably, other classes of enzyme inducers.


    MATERIALS AND METHODS
 Top
 ABSTRACT
 INTRODUCTION
 MATERIALS AND METHODS
 RESULTS
 DISCUSSION
 REFERENCES
 
Reagents.
L-Sulforaphane was purchased from LKT Laboratories (St. Paul, MN). A nucleotide removal kit was procured from Qiagen (Valencia, CA). NADPH, malate, glucose-6-phosphate, 1-chloro-2,4-dinitrobenzene, p-nitrophenylacetate, NAD+, and menadione were purchased from Sigma Chemical Co. (St. Louis, MO).

Animals.
Experiments were conducted in accordance with the standards established by the United States Animal Welfare Acts, set forth in NIH guidelines and the Policy and Procedures Manual of the Johns Hopkins University Animal Care and Use Committee. Nrf2-deficient ICR mice were generated as described (8) . Genotypes of homozygous wild-type and nrf2-deficient mice (10 weeks of age) were confirmed by PCR amplification of genomic DNA extracted from blood or liver. PCR amplification was carried out by using three different primers, 5'-TGGACGGGACTATTGAAGGCTG-3' (sense for both genotypes), 5'-CGCCTTTTCAGTAGATGGAGG-3' (antisense for wild type), and 5'-GCGGATTGACCGTAATGGGATAGG-3' (antisense for LacZ), as described previously (7) .

Female mice [wild-type nrf2 (+/+) and nrf2 (-/-) deficient], 10 weeks of age, were maintained on an AIN 76A diet and water ad libitum and housed at a temperature range of 20–23°C under 12-h light/dark cycles. The mice were grouped into four groups (n = 3): I, control (nrf2 +/+) wild type; II, treatment (nrf2 +/+) wild type; III, control knock out (nrf2 -/-); and IV, treatment knock out (nrf2 -/-). The control and treatment groups were administered either vehicle (corn oil) alone or sulforaphane (9 µmol/mouse/day) by gavage (0.2 ml), respectively, for 7 consecutive days. Body weights were recorded to monitor the health of animals. Animals were sacrificed by cervical dislocation 24 h after the last dose. The small intestine was removed and washed thoroughly with ice-cold PBS to remove the fecal material and frozen in liquid nitrogen before storage at -80°C until further use.

Northern Blotting.
Total RNA from the intestine was extracted with TRIzol reagent (Life Technologies, Inc., Grand Island, NY) according to the manufacturer’s instructions. Total RNA (10 µg) was separated on 1.2% agarose gels containing 2.2 M formaldehyde, transferred to nylon membranes (Nytran Super Charge; Schleicher and Schuell, Dassel, Germany), and UV-cross-linked. Probes for NAD(P)H:quinone oxidoreductase (NQO1), GST Ya, {gamma}-GCS (regulatory subunit), UDP-glucuronosyltransferases (UGT1A6), malic enzyme, glutathione reductase, and ß-actin were generated by PCR from the cDNA of murine liver. These PCR products were radiolabeled with [{alpha}-32P]dCTP using a random primers DNA labeling kit (Invitrogen, San Diego, CA). Northern hybridization was done using QuickHyb (Stratagene, Carlsbad, CA) as per the manufacturer’s protocol. After hybridization, the membranes were washed twice in 0.2% SSC (1x SSC is 0.15 M NaCl/0.015 M sodium citrate) containing 0.1% (w/v) SDS at room temperature for 15 min and finally in 0.1% SSC/0.1% SDS at 60°C for 45 min. The membranes were exposed to a phosphorimager screen, and radioactivity was visualized and quantified with a BAS1000 Bioimaging system (Fuji Photo Film, Tokyo, Japan). Levels of RNA were quantified and normalized for RNA loading by stripping and reprobing the blots with a probe for ß-actin.

Transcriptional Profiling by Oligonucleotide Microarray.
Total RNA was purified with the RNeasy Mini kit (Qiagen, Valencia, CA) after isolation with TRIzol reagent as described above and was used for experiments with Murine Genome U74A version 2 GeneChip arrays (Affymetrix, Santa Clara, CA), which contain probes for detecting ~6000 well-characterized genes and 6000 expressed sequence tags (ESTs). Briefly, double-stranded cDNA was synthesized from 15 µg of total RNA with SuperScript Choice System (Invitrogen) by using oligo(dT)24 primers with a T7 RNA polymerase promoter site added to its 3' end (Genset Corp., La Jolla, CA). The isolated cDNA was then labeled to generate biotinylated cRNA in vitro and amplified using the BioArray T7 RNA polymerase labeling kit (Enzo, Farmingdale, NY). After purification of the cRNA by RNeasy Mini kit, 20 µg of cRNA were fragmented at 94°C for 35 min. Approximately 12.5 µg of fragmented cRNA was used in a 250-µl hybridization mixture containing herring sperm DNA (0.1 mg/ml; Promega Corp., Madison, WI), plus bacterial and phage cRNA controls (1.5 pmol of BioB, 5 pmol of BioC, 25 pmol of BioD, and 100 pmol of Cre) to serve as internal controls for hybridization efficiency as directed by the manufacturer (Affymetrix). Aliquots (200 µl) of the mixture were hybridized onto the array for 18 h at 45°C in a GeneChip Hybridization Oven 640 (Affymetrix). Each array was washed and stained with streptavidin-phycoerythrin (Molecular Probes, Eugene, OR) and amplified with biotinylated anti-streptavidin antibody (Vector Laboratory, Burlingame, CA) on the GeneChip Fluidics Station 400 (Affymetrix). Each array was scanned with the GeneArray scanner (Agilent Technologies, Palo Alto, CA) to obtain image and signal intensities.

Data Analysis Using Affymetrix Software.
Scanned output files were analyzed with the Affymetrix Microarray Suite 5.0 and normalized to an average intensity of 500 independently, before comparison. To identify differentially expressed transcripts, pairwise comparison analysis were carried out with Data Mining Tool 3.0 (Affymetrix). The analysis compares the differences in values of perfect match to mismatch of each probe pair in the baseline array to its matching probe pair on the experimental array. Ps were determined by the Wilcoxon’s signed rank test and denoted as increase, decrease, or no change. Analysis using Data Mining Tool also provides the signal log ratio, which estimates the magnitude and direction of change of a transcript when two arrays are compared (experimental versus baseline). We have converted the signal log ratio output into fold change for convenience using the formula recommended by Affymetrix:

In the present study, we performed nine pairwise comparisons for each group (experimental, n = 3 versus baseline, n = 3). Only those altered genes that appeared in at least seven of the nine comparisons were selected. This conservative analytical approach was used to limit the number of false positives. In addition, we also performed a Mann-Whitney pairwise comparison test in Data Mining Tool to rank the results by concordance as a calculation of significance (P) of each identified change in gene expression. The ESTs obtained in the data were searched for their recent annotation using the "Analysis Center" at the Affymetrix site (www.netaffx.com).

Enzyme Activity Assays.
Total GST activity was measured in cytosolic fractions (100,000 x g) in the presence of 0.1% BSA with 1-chloro-2,4-dinitrobenzene as a substrate (23) , whereas NQO1 activity was determined using menadione as substrate (24) . Activity of G6PDH was determined from the rate of glucose 6-phosphate-dependent reduction of NADP+ (25) . Malic enzyme activity was measured from the rate of malate-dependent NADP+ reduction (26) . Carboxylesterase activity was determined by measuring the hydrolysis of p-nitrophenyl acetate to p-nitrophenol at 410 nm (27) . UDP-glucose dehydrogenase activity was measured by the reduction of NAD+ in the presence of UDP-glucose at 340 nm (28) . Protein concentration was determined by using the Bio-Rad DC reagent and BSA as the standard.

Statistics.
The values for enzyme-specific activities are mean ± SE, and the Student t test was used to analyze the statistical significance.


    RESULTS
 Top
 ABSTRACT
 INTRODUCTION
 MATERIALS AND METHODS
 RESULTS
 DISCUSSION
 REFERENCES
 
Microarray Analysis.
The transcriptional profile of a target organ, the small intestine of Nrf2wild-type and -deficient mice with or without sulforaphane treatment was generated using the Murine Genome U74Av2 chip. The obtained transcriptional profile was logically analyzed to derive the set of genes regulated by Nrf2. We performed three categories of comparisons (Fig. 1)Citation to accomplish the objective. Because Nrf2 is well established in the positive regulation of genes (15) , we have concentrated only on up-regulated genes.4 The gene profile that emerged after comparative analysis was further filtered. The genes that appeared in at least seven of the nine comparisons that showed fold changes >1.5 and had Ps of <=0.05 were selected. These cutoff values gave a conservative estimate of the number of genes in each category, and only those genes complying with the criteria were considered further.



View larger version (15K):
[in this window]
[in a new window]
[Download PPT slide]
 
Fig. 1. Schematic depicting the strategy for comparison and analysis of transcriptional profiles obtained from microarray using the Affymetrix Murine Genome U74A version 2 arrays that contain probes for detecting ~6000 well-characterized genes and 6000 expressed sequence tags. Wild type, nrf2 +/+ mice; knock out, nrf2 -/- mice.

 
Wild-Type Control and Nrf2-deficient Control.
In this category, the altered gene profile reflects the effect of disruption of Nrf2. Overall, there were 45 genes and 27 ESTs with higher expression in the wild-type mice. Prominent genes showing large fold changes were carboxyl esterase (15-fold), epoxide hydrolase (12-fold), various GSTs (3–6-fold), malic enzyme (3.5-fold), UGT (8-fold), aldehyde dehydrogenase II (4.6-fold), and NQO1 (3-fold).

Wild-Type Treated and Wild-Type Control.
The altered transcriptional profile in this comparison group is the result of treatment with sulforaphane. Thirty-three genes and 17 ESTs were induced by sulforaphane. The most responsive genes in this class of comparison were GSTs(2.5–6-fold), catalytic subunit of GCS (4-fold), fibroblast growth factor related protein (3-fold), carboxyl esterase (4-fold), and NQO1 (2.5-fold).

Nrf2-deficient Treated and Nrf2-deficient Control.
This profile also includes genes induced by sulforaphane; however, Nrf2 does not regulate them. There were 59 genes and 62 ESTs, of which the most responsive genes were histone genes (H2B and H2A; 5-fold) and mouse immunoglobulin-active {lambda}-1-chain V-region (V-J) gene (2.5-fold).

Nrf2-dependent Genes.
To identify the gene targets of Nrf2 based on the transcriptional pattern of gene expression, we adopted a specific strategy of analysis that is depicted in Fig. 1Citation . Our analysis revealed 77 up-regulated genes whose expression was influenced by Nrf2 (Table 1)Citation . They can be classified into three different categories based on their dependence on Nrf2. For basal expression, the expressions of this class of genes were elevated in wild-type control mice compared with nrf2-deficient mice and were not effected by sulforaphane in either genotype, suggesting that these genes require Nrf2 for their basal but not inducible expression. For inducible expression, this subset of genes was elevated in the sulforaphane-treated, wild-type group relative to vehicle-treated, wild-type and nrf2-deficient mice and were not induced in sulforaphane-treated, nrf2-deficient mice, demonstrating their dependence on Nrf2 for induction. For basal and inducible expression, this class of genes was elevated in vehicle-treated, wild-type mice when compared with the nrf2-deficient mice and selectively induced in response to sulforaphane in the wild-type mice only. Thus, these genes are dependent on Nrf2 for basal as well as inducible expression. All genes belonging to these three groups are presented in Table 1Citation , together with fold change and mode of dependence on Nrf2. Genes elevated in the nrf2-deficient, treated and nrf2-deficient, control comparison are considered to be Nrf2-independent genes and are included as supplementary data at the web site.


View this table:
[in this window]
[in a new window]

 
Table 1 Nrf2 up-regulated genes obtained from the screening

 
We have further categorized the Nrf2 up-regulated genes based on their functions (Table 1)Citation . The majority of the up-regulated genes at the inducible and/or basal level are associated with various metabolic reactions (hydrolysis, reduction, oxidation, and conjugation with endogenous ligands: glutathione and glucuronide) involved in detoxication of electrophiles and free radicals. Antioxidative genes such as glutathione peroxidase, glutathione reductase, ferritin, and haptaglobinand the genes encoding NADPH-generating enzymes, i.e., glucose 6-phosphate dehydrogenase, malic enzyme, and 6-phosphogluconate dehydrogenasewere also dependent on Nrf2 for expression.

Validation of Microarray Data by Northern Blot.
Four well-characterized Nrf2 regulated genes, NQO1, GST Ya, {gamma}-GCS(h), and UGT 1A6 and two new genes identified by this screening, malic enzymeand glutathione reductase, were selected for verification of the transcriptional changes using Northern hybridization. The fold changes [NQO1, 2.5-fold; GST Ya, 2 fold; {gamma}-GCS(h), 3-fold; UGT 1A6, 1.4-fold; malic enzyme, 1.8-fold; and glutathione reductase, 2-fold] in sulforaphane-treated, wild-type mice compared with vehicle-treated, wild-type mice are in close agreement with the oligonucleotide array data (Fig. 2A)Citation . Furthermore, lower expression of these genes in nrf2-deficient mice compared with wild-type mice is consistent with the transcriptional changes observed by microarray.



View larger version (54K):
[in this window]
[in a new window]
[Download PPT slide]
 
Fig. 2. A, Northern blot analysis of mRNA levels of NQO1, GST (Ya), GCS (h), UGT, malic enzyme, and glutathione reductase in small intestine of wild-type [nrf2 (+/+)] and nrf2-deficient [nrf2 (-/-)] mice treated with either vehicle (corn oil) or sulforaphane to show the basal and inducible expression. B, GST and NQO1 activities in the cytosolic fractions of small intestine of wild-type [nrf2 (+/+)] and nrf2-deficient [nrf2 (-/-)] mice treated with vehicle (corn oil) or sulforaphane. The activities of both enzymes are elevated only in sulforaphane-treated nrf2+/+ mice. Values represent means (n = 3); bars, SE. *, significantly greater from control of same genotypes, P < 0.05 (analyzed by Student’s t test).

 
Enzyme Assays of Selected Genes.
Six genes were selected for enzymatic assays (Figs. 2BCitation and 3Citation ). NQO1 and GST enzyme activities were induced 1.6- and 1.3-fold, respectively, by treatment of wild-type mice with sulforaphane. Moreover, their basal activities were significantly lower in the untreated nrf2-deficient mice when compared with the untreated wild-type mice. Malic enzyme and glucose 6-phosphate dehydrogenase activities were induced to 1.8- and 10.3-fold, respectively, and there were significant differences in basal activities between the wild-type and knock-out mice. There was 1.3-fold difference in the basal activity of UDP-glucose dehydrogenase between wild-type and nrf2-deficient mice, and significant induction was seen with sulforaphane treatment in wild-type mice. Carboxylesterase activity showed a modest induction of 1.3-fold in response to sulforaphane only in wild-type mice (Fig. 3)Citation . In general, the fold increases in enzyme activities were lower than those observed for the increases in transcript levels.



View larger version (33K):
[in this window]
[in a new window]
[Download PPT slide]
 
Fig. 3. Specific activities of selected enzymes in the cytosolic fractions of small intestine of wild-type [nrf2 (+/+)] and nrf2-deficient [nrf2 (-/-)] mice treated with sulforaphane. The activities of all of the enzymes are elevated only in sulforaphane-treated nrf2 +/+ mice. Values represent means (n = 3); bars, SE. *, significantly greater from control of same genotypes, P < 0.05 (analyzed by Student’s t test).

 

    DISCUSSION
 Top
 ABSTRACT
 INTRODUCTION
 MATERIALS AND METHODS
 RESULTS
 DISCUSSION
 REFERENCES
 
Previous studies using biochemical and Northern blot analyses in wild-type and nrf2-deficient mice have demonstrated that Nrf2 controls the constitutive expression of antioxidative enzymes such as the light regulatory subunit of {gamma}-glutamylcysteine synthetase, heme oxygenase 1, and peroxiredoxin MSP23 (29) and also mediates induction of hepatic and intestinal NQO1 and GST enzymes by butylated hydroxytoluene, oltipraz, and sulforaphane (8 , 11) . In the present investigation, we have compared the transcriptional profile of small intestine of nrf2 wild-type and nrf2-deficient mice with and without sulforaphane treatment, a potent chemopreventive agent that activates the Nrf2 pathway (30) , and identified several new target genes that are positively regulated at the basal and/or inducible level by Nrf2. Interestingly, most of the proteins that are positively regulated through Nrf2 are implicated directly or indirectly in counteracting the cellular stress induced by a wide spectrum of electrophiles and free radicals (Table 1)Citation .

Fig. 1Citation depicts the strategy and the outcomes of the comparisons of transcriptional profiles obtained from the different treatment groups. The strategy we used of comparative analysis of transcriptional profile resulted in both up-regulated and down-regulated genes in each category of comparison. Our focus in the present investigation has been only on genes that are positively regulated by Nrf2, because most of the detoxifying phase 2 proteins depend on this transcription factor for their constitutive and or inducible synthesis. The down-regulated genes in sulforaphane treated/vehicle control comparison using nrf2-deficient mice cannot be attributed to Nrf2; however, the role of Nrf2 in the repression of these genes that are present exclusively in "wild type treatment/wild type control" comparisons cannot go unnoticed. It is reported that the balance in expression of Nrf2 and its small maf binding proteins can affect the positive or negative regulation of some genes (31) .

Two major cellular pathways of detoxication, i.e., glucuronidation and glutathione conjugation, appeared to be even more dependent on Nrf2-regulated genes than thought previously. The glucuronidation pathway enhances the elimination of many lipophilic xenobiotics and endobiotics by conversion to more water-soluble compounds. Glucuronidation requires the cofactor UDP-glucuronic acid, and the reaction is catalyzed by a family of UGTs, some members of which are well-characterized Nrf2-regulated genes (32) . In the present investigation, we found several new Nrf2-dependent genes (transketolase, transaldolase, fructose bisphosphatase, phosphoglucomutase, and UDP-glucose dehydrogenase), which are associated with metabolic pathways that may directly or indirectly aid the glucuronidation process (Fig. 4)Citation . Transketolase and transaldolase catalyzes the formation of fructose-6-phosphate from the products derived from ribulose-5-phosphate. Furthermore, fructose 1,6-bisphosphatase also catalyzes the conversion of fructose 1,6-bisphosphate to fructose-6-phosphate. Both these reactions may increase the influx of fructose-6-phosphate, which after conversion to glucose-6-phosphate forms glucose-1-phosphate by the action of phosphoglucomutase (Fig. 4)Citation . The UDP-glucose that provides the glucuronic acid for UGT-mediated conjugation with xenobiotics is formed from glucose-1-phosphate by UDP-glucose dehydrogenase.



View larger version (50K):
[in this window]
[in a new window]
[Download PPT slide]
 
Fig. 4. Probable network of Nrf2-regulated genes involved in the detoxication process. *, genes containing ARE that are known to be regulated by Nrf2. **, genes with ARE.

 
GSTs constitute a family of enzymes that detoxify xenobiotics by conjugating glutathione to a range of electrophilic substrates. The cytosolic GSTs are currently divided into at least eight classes on the basis of their physical and chemical properties (33) . In our study, we have found several Nrf2-dependent genes coding for isozymes of GST, including GST mu (GST5-5), GST mu 1, GST GT8.7, GST GT9.3, GST {alpha}3, GST {alpha}2 (Yc2), GST {alpha}1 (Ya). In addition, a few ESTs that were homologous to human GST [GST M2 (muscle), microsomal GST 3, and microsomal GST 2] and rat GST required Nrf2 for either basal or inducible expression.

Glutathione using genes such as GR and GPX [other than the well-known Nrf2 targets, GST(33) and {gamma}-GCS(34) ] were up-regulated in wild-type mice. GR, which is involved in the production of reduced glutathione by using NADPH, is up-regulated only in wild-type sulforaphane-treated mice, suggesting the role of Nrf2 in its induction, whereas GPX, which is involved in detoxifying various free radicals and peroxides by consuming glutathione (35) , was found to be elevated only in the wild-type control mice, indicating the dependence of Nrf2 for basal expression. Lack of or low expression of all these glutathione-associated genes in nrf2-deficient mice undoubtedly makes them more susceptible to xenobiotic toxicities (12 , 14) .

Other than NQO1 (36) and epoxide hydrolase (3) , which are known Nrf2 targets, additional targets of xenobiotic detoxication genes regulated by Nrf2 obtained from the screening can be grouped as oxido-reductase, hydrolytic, and oxidative detoxication enzymes. Carbonyl reductase, aldose reductase (fibroblast growth factor regulated protein), aldo-keto reductase, and aflatoxin aldehyde reductase belong to a class of NADPH-dependent oxido-reductases catalyzing the reduction of aldehyde and keto groups of several endogenous and exogenous compounds. The broad range of substrates includes acrolein, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone, prostaglandins, steroids, pterins, and biogenic amines (37, 38, 39, 40, 41, 42) . Carboxylesterase and peptidases belong to the hydrolytic class of detoxication enzymes. Carboxylesterase hydrolyzes xenobiotics containing functional groups such as carboxylic esters (procaine), amides (procainamide), and thioesters (spironolactone; Ref. 43 ). Several oxidative enzymes, such as aldehyde dehydrogenase, monoamine oxidase, and amino oxidase, are also regulated by Nrf2. ALDH enzymes are involved in the oxidation of xenobiotic aldehydes (44) and also possess esterase activity. ALDH2, one of the genes identified in our investigation, is a mitochondrial enzyme that appears to be regulated by Nrf2. It is primarily responsible for oxidizing simple aldehydes such as acetaldehydes (45) . Interestingly, the presence of AREs in the 5' upstream region of ALDH was shown recently (46) . This observation is consistent with our findings and suggests the positive regulation by Nrf2 on these classes of genes. Monoamine oxidase, an integral protein of the mitochondria outer membrane is a flavoenzyme that is dependent on Nrf2 for basal expression. It catalyzes the oxidation of structurally diverse amines and xenobiotics such as the neurotoxins 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (47) . Leukotriene B4 hydroxydehydrogenase is another basal and inducible oxidoreductase regulated by Nrf2 that has been found to be effective in catalyzing the hydrogenation and detoxication of wide variety of cytotoxic and mutagenic {alpha},ß-unsaturated aldehydes and ketones that are major toxic environmental pollutants and products of lipid peroxidation (48, 49, 50) .

The genes coding for NADPH generating enzymes, such as G6PDH and malic enzyme, were elevated only in the wild-type control mice, suggesting the dependence of these genes on Nrf2 for basal expression. Recently, malic enzyme has been reported to contain an ARE in its promoter region, which corroborates well with our observation (51) . However, another NADPH-generating enzyme, 6PGDH, was up-regulated in wild-type mice in response to sulforaphane, indicating that its induction is mediated by Nrf2 (52 , 53) . Increased formation of NADPH may prove to be beneficial because it is involved in the microsomal monooxygenation of xenobiotics, reductive biosynthesis, maintenance of redox state, and also acts as a potent antioxidant (direct and indirect; Ref. 54 ). The hexose shunt enzymes, G6PDH and 6PGDH, are also responsible for generating the ribose-5-phosphate necessary for nucleic acid biosynthesis and repair. The coordinated expression of all of these genes involved in detoxication, antioxidant status, and repair suggests an important role for Nrf2 in regulating the cellular defenses against carcinogenic challenges by increasing the reductive capacity of the cell. The microarray data were verified by the observed increases in enzyme activity of G6PDH and malic enzyme in the intestine of wild- type mice treated with sulforaphane (Fig. 3)Citation . Although the impact of Nrf2 genotype on the transcript levels of the genes coding G6PDH and malic enzyme appeared to be on basal expression, the activities of these enzymes were elevated in wild-type mice by sulforaphane treatment (nearly 10-fold and 2-fold higher when compared with vehicle, respectively). Also, there was significant increase in G6PDH activity in nrf2-deficient mice after treatment with sulforaphane, suggesting that the induction of this enzyme is partly controlled by other transcription factors.

Apart from enzymes, several cytoprotective proteins involved in lessening electrophile toxicity and oxidative stress appear to be regulated through Nrf2. Ferritin (light chain), an antioxidant, known to possess an ARE (55) , requires Nrf2 for basal expression. HSP 40, a cofactor for HSP 70, the expression of which is up-regulated by a variety of cellular stresses (56) , requires Nrf2 for induction. Another antioxidant protein, haptaglobin, an acute phase protein capable of binding to hemoglobin, thus preventing iron loss and renal damage, is also dependent on Nrf2 for basal expression (57) . Multidrug resistance protein is elevated only in wild-type control, suggesting that Nrf2 contributes to its basal expression. Multidrug resistance protein is a ubiquitously expressed protein with several physiological functions, such as protection against heavy metal oxyanions, modulation of the activity of ion channels, and transport of leukotriene C4 and other glutathione conjugates and glucuronides (58) .

We have identified a number of Nrf2-dependent genes (for either basal or inducible expression) that are involved in different biological functions such as ornithine aminotransferase[protects against ammonia intoxication (59) ], tryptophan hydrolase, aromatic amino acid decarboxylase, nucleoside diphosphatase, putative membrane-associated progesterone receptor, and glucocorticoid-regulated kinase. The screening also enabled us to identify genes that are induced in response to sulforaphane but not regulated by Nrf2 (genes up-regulated in nrf2-deficient treated/nrf2-deficient control comparison).

The time of sampling point is very critical to monitor the transcriptional activation of any gene. Probably in the present investigation at the selected sampling point (24 h after the last dose), there may be certain genes whose transcriptional activity might have returned to basal expression levels; such differential outcome between transcript and protein levels has been observed with hepatic GST Ya in oltipraz-treated rats (60) . Similarly, with G6PDH and malic enzyme, enzyme activities were high at the selected time point after sulforaphane treatment, but the transcript levels were basal as determined by our microarray data analysis. In addition to the dynamic influence of time of sampling, potency and efficacy of different Nrf2 activators will vary with chemical class and target tissue. Thus, studies of the transcriptional profiles with different Nrf2 activators in various tissues at a range of sampling points may result in identification of additional sets of Nrf2-dependent genes that our study is unable to reveal.

This study expands the scope of the positive, coordinated regulation of a wide variety of cellular defense proteins by Nrf2 and underscores the potential of Nrf2 activation as a strategy for achieving cancer chemoprevention. The genes regulated by Nrf2 include detoxication enzymes as well as antioxidative and cytoprotective proteins that can collectively alleviate the toxicities mediated by a broad range of electrophiles and reactive oxygen species. Future studies aimed at searching for AREs in the promoter of these target genes of Nrf2 will help in deciphering the direct and indirect role of this transcription factor in these actions. In conclusion, this study expands the molecular basis by which the cancer preventive agents such as sulforaphane exert protective efficacy against a broad spectrum of exogenous and endogenous toxicants. Furthermore, understanding of the downstream molecular targets of these anticarcinogens will facilitate their development and use in clinical interventions (61) .


    FOOTNOTES
 
The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked advertisement in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.

1 Supported by grants from the Maryland Cigarette Restitution Fund (to S. B.), the American Cancer Society (to S. B.), R01 CA94076 (to T. W. K.), P01 ES06052 (to T. W. K.), and National Institute of Environmental Health Sciences Centre grant ES06052. Back

2 To whom requests for reprints should be addressed, at Department of Environmental Health Sciences, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205. E-mail: sbiswal{at}jhsph.edu Back

3 The abbreviations used are: {gamma}-GCS, {gamma}-glutamylcysteine synthetase; {gamma}-GCS(h), heavy catalytic subunit of {gamma}-GCS; EST, expressed sequence tag; ALDH, aldehyde dehydrogenase; ARE, antioxidant response element; HSP, heat shock protein; G6PDH, glucose-6-phosphate dehydrogenase; GPX, glutathione peroxidase; GR, glutathione reductase; GST, glutathione S-transferase; NQO1, NAD(P)H:quinone reductase; Nrf2, nuclear factor E2 p45-related factor 2; 6PGDH, 6-phsophogluconate dehydrogenase; UGT, UDP-glucuronosyltransferase. Back

4 The comprehensive lists of all up-regulated and down-regulated genes in the comparisons are reported in http://commprojects.jhsph.edu/ehs/biswal_data.xls. Back

Received 4/ 3/02. Accepted 7/ 9/02.


    REFERENCES
 Top
 ABSTRACT
 INTRODUCTION
 MATERIALS AND METHODS
 RESULTS
 DISCUSSION
 REFERENCES
 

  1. Block G., Patterson B., Subar A. Fruit, vegetables, and cancer prevention: a review of the epidemiological evidence. Nutr. Cancer, 18: 1-29, 1992.[Medline]
  2. Steinkellner H., Rabot S., Freywald C., Nobis E., Scharf G., Chabicovsky M., Knasmuller S., Kassie F. Effects of cruciferous vegetables and their constituents on drug metabolizing enzymes involved in the bioactivation of DNA-reactive dietary carcinogens. Mutat. Res., 480–481: 285-297, 2001.
  3. Talalay P. Chemoprotection against cancer by induction of phase 2 enzymes. Biofactors, 12: 5-11, 2000.[Medline]
  4. Wasserman W. W., Fahl W. E. Functional antioxidant responsive elements. Proc. Natl. Acad. Sci. USA, 94: 5361-5366, 1997.[Abstract/Free Full Text]
  5. Zhu M., Fahl W. E. Functional characterization of transcription regulators that interact with the electrophile response element. Biochem. Biophys. Res. Commun., 289: 212-219, 2001.[Medline]
  6. Nguyen T., Huang H. C., Pickett C. B. Transcriptional regulation of the antioxidant response element. Activation by Nrf2 and repression by MafK. J. Biol. Chem., 275: 15466-15473, 2000.[Abstract/Free Full Text]
  7. Ramos-Gomez M., Kwak M. K., Dolan P. M., Itoh K., Yamamoto M., Talalay P., Kensler T. W. Sensitivity to carcinogenesis is increased and chemoprotective efficacy of enzyme inducers is lost in Nrf2 transcription factor-deficient mice. Proc. Natl. Acad. Sci. USA, 98: 3410-3415, 2001.[Abstract/Free Full Text]
  8. Itoh K., Chiba T., Takahashi S., Ishii T., Igarashi K., Katoh Y., Oyake T., Hayashi N., Satoh K., Hatayama I., Yamamoto M., Nabeshima Y. An Nrf2/small Maf heterodimer mediates the induction of Phase II detoxifying enzyme genes through antioxidant response elements. Biochem. Biophys. Res. Commun., 236: 313-322, 1997.[Medline]
  9. Itoh K., Wakabayashi N., Katoh Y., Ishii T., Igarashi K., Engel J. D., Yamamoto M. Keap1 represses nuclear activation of antioxidant responsive elements by Nrf2 through binding to the amino-terminal Neh2 domain. Genes Dev., 13: 76-86, 1999.[Abstract/Free Full Text]
  10. McMahon M., Itoh K., Yamamoto M., Chanas S. A., Henderson C. J., McLellan L. I., Wolf C. R., Cavin C., Hayes J. D. The Cap’n’Collar basic leucine zipper transcription factor Nrf2 (NF-E2 p45-related factor 2) controls both constitutive and inducible expression of intestinal detoxification and glutathione biosynthetic enzymes. Cancer Res., 61: 3299-3307, 2001.[Abstract/Free Full Text]
  11. Hayes J. D., McMahon M. Molecular basis for the contribution of the ARE to cancer chemoprevention. Cancer Lett., 174: 103-113, 2001.[Medline]
  12. Enomoto A., Itoh K., Nagayoshi E., Haruta J., Kimura T., O’Connor T., Harada T., Yamamoto M. High sensitivity of Nrf2 knockout mice to acetaminophen hepatotoxicity associated with decreased expression of ARE-regulated drug metabolizing enzymes and antioxidant genes. Toxicol. Sci., 59: 169-177, 2001.[Abstract/Free Full Text]
  13. Chan K., Kan Y. W. Nrf2 is essential for protection against acute pulmonary injury in mice. Proc. Natl. Acad. Sci. USA, 96: 12731-12736, 1999.[Abstract/Free Full Text]
  14. Aoki Y., Sato H., Nishimura N., Takahashi S., Itoh K., Yamamoto M. Accelerated DNA adduct formation in the lung of the Nrf2 knockout mouse exposed to diesel exhaust. Toxicol. Appl. Pharmacol., 173: 154-160, 2001.[Medline]
  15. Kwak M-K., Itoh K., Yamamoto M., Sutter T. R., Kensler T. W. Role of transcription factor Nrf2 in the induction of hepatic phase 2 and antioxidative enzymes in vivo by the cancer chemopreventive agent, 3H-1, 2 dithiole-3 thione. Mol. Med., 7: 135-145, 2001.[Medline]
  16. Lin H. J., Probst-Hensch N. M., Louie A. D., Kau I. H., Witte J. S., Ingles S. A., Frankl H. D., Lee E. R., Haile R. W. Glutathione transferase null genotype, broccoli, and lower prevalence of colorectal adenomas. Cancer Epidemiol. Biomark. Prev., 7: 647-652, 1998.[Abstract]
  17. London S. J., Yuan J. M., Chung F. L., Gao Y. T., Coetzee G. A., Ross R. K., Yu M. C. Isothiocyanates, glutathione S-transferase M1 and T1 polymorphisms, and lung-cancer risk: a prospective study of men in Shanghai, China. Lancet, 356: 724-729, 2000.[Medline]
  18. Zhao B., Seow A., Lee E. J., Poh W. T., Teh M., Eng P., Wang Y. T., Tan W. C., Yu M. C., Lee H. P. Dietary isothiocyanates, glutathione S-transferase-M1, -T1 polymorphisms and lung cancer risk among Chinese women in Singapore. Cancer Epidemiol. Biomark. Prev., 10: 1063-1067, 2001.[Abstract/Free Full Text]
  19. Fahey J. W., Zhang Y., Talalay P. Broccoli sprouts: an exceptionally rich source of inducers of enzymes that protect against chemical carcinogens. Proc. Natl. Acad. Sci. USA, 94: 10367-10372, 1997.[Abstract/Free Full Text]
  20. Prochaska H. J., Santamaria A. B., Talalay P. Rapid detection of inducers of enzymes that protect against carcinogens. Proc. Natl. Acad. Sci. USA, 89: 2394-2398, 1992.[Abstract/Free Full Text]
  21. Zhang Y., Talalay P., Cho C. G., Posner G. H. A major inducer of anticarcinogenic protective enzymes from broccoli: isolation and elucidation of structure. Proc. Natl. Acad. Sci. USA, 89: 2399-2403, 1992.[Abstract/Free Full Text]
  22. Chung F. L., Conaway C. C., Rao C. V., Reddy B. S. Chemoprevention of colonic aberrant crypt foci in Fischer rats by sulforaphane and phenethyl isothiocyanate. Carcinogenesis (Lond.), 21: 2287-2291, 2000.[Abstract/Free Full Text]
  23. Habig W. H., Pabst M. J., Jakoby W. B. Glutathione S-transferases. The first enzymatic step in mercapturic acid formation. J. Biol. Chem., 249: 7130-7139, 1974.[Abstract/Free Full Text]
  24. Prochaska H. J., Santamaria A. B. Direct measurement of NAD(P)H: quinone reductase from cells cultured in microtiter wells: a screening assay for anticarcinogenic enzyme inducers. Anal. Biochem., 169: 328-336, 1988.[Medline]
  25. Lee C. Y. Glucose-6-phosphate dehydrogenase from mouse. Methods Enzymol., 89: 252-257, 1982.
  26. Hsu R. Y., Lardy H. A. Pigeon liver malic enzyme.II. Isolation, crystallization,andsomeproperties. J.Biol.Chem., 242: 520-526, 1967.[Abstract/Free Full Text]
  27. Morgan E. W., Yan B., Greenway D., Parkinson A. Regulation of two rat liver microsomal carboxylesterase isozymes: species differences, tissue distribution, and the effects of age, sex, and xenobiotic treatment of rats. Arch. Biochem. Biophys., 315: 513-526, 1994.[Medline]
  28. Spicer A. P., Kaback L. A., Smith T. J., Seldin M. F. Molecular cloning and characterization of the human and mouse UDP- glucose dehydrogenase genes. J. Biol. Chem., 273: 25117-25124, 1998.[Abstract/Free Full Text]
  29. Ishii T., Itoh K., Takahashi S., Sato H., Yanagawa T., Katoh Y., Bannai S., Yamamoto M. Transcription factor Nrf2 coordinately regulates a group of oxidative stress-inducible genes in macrophages. J. Biol. Chem., 275: 16023-16029, 2000.[Abstract/Free Full Text]
  30. Morimitsu Y., Nakagawa Y., Hayashi K., Fujii H., Kumagai T., Nakamura Y., Osawa T., Horio F., Itoh K., Iida K., Yamamoto M., Uchida K. A sulforaphane analogue that potently activates the Nrf2-dependent detoxification pathway. J. Biol. Chem., 277: 3456-3463, 2002.[Abstract/Free Full Text]
  31. Motohashi H., Katsuoka F., Shavit J. A., Engel J. D., Yamamoto M. Positive or negative MARE-dependent transcriptional regulation is determined by the abundance of small Maf proteins. Cell, 103: 865-875, 2000.[Medline]
  32. King C. D., Rios G. R., Green M. D., Tephly T. R. UDP-glucuronosyltransferases. Curr. Drug Metab., 1: 143-161, 2000.[Medline]
  33. Ketterer B. A bird’s eye view of the glutathione transferase field. Chem. Biol. Interact., 138: 27-42, 2001.[Medline]
  34. Griffith O. W. Biologic and pharmacologic regulation of mammalian glutathione synthesis. Free Radical Biol. Med., 27: 922-935, 1999.[Medline]
  35. Arthur J. R. The glutathione peroxidases. Cell Mol. Life Sci., 57: 1825-1835, 2000.[Medline]
  36. Chesis P. L., Levin D. E., Smith M. T., Ernster L., Ames B. N. Mutagenicity of quinones: pathways of metabolic activation and detoxification. Proc. Natl. Acad. Sci. USA, 81: 1696-1700, 1984.[Abstract/Free Full Text]
  37. Kolb N. S., Hunsaker L. A., Vander Jagt D. L. Aldose reductase-catalyzed reduction of acrolein: implications in cyclophosphamide toxicity. Mol. Pharmacol., 45: 797-801, 1994.[Abstract]
  38. Atalla A., Breyer-Pfaff U., Maser E. Purification and characterization of oxidoreductases-catalyzing carbonyl reduction of the tobacco-specific nitrosamine 4-methylnitrosamino-1-(3-pyridyl)-1-butanone (NNK) in human liver cytosol. Xenobiotica, 30: 755-769, 2000.[Medline]
  39. Forrest G. L., Gonzalez B. Carbonyl reductase. Chem. Biol. Interact., 129: 21-40, 2000.[Medline]
  40. Jez J. M., Flynn T. G., Penning T. M. A new nomenclature for the aldo-keto reductase superfamily. Biochem. Pharmacol., 54: 639-647, 1997.[Medline]
  41. Ellis E. M., Hayes J. D. Substrate specificity of an aflatoxin-metabolizing aldehyde reductase. Biochem. J., 312: 535-541, 1995.
  42. Bohren K. M., Bullock B., Wermuth B., Gabbay K. H. The aldo-keto reductase superfamily. cDNAs and deduced amino acid sequences of human aldehyde and aldose reductases. J. Biol. Chem., 264: 9547-9551, 1989.[Abstract/Free Full Text]
  43. Satoh T., Hosokawa M. The mammalian carboxylesterases: from molecules to functions. Annu. Rev. Pharmacol. Toxicol., 38: 257-288, 1998.[Medline]
  44. Goedde H. W., Agarwal D. P., Fritze G., Meier-Tackmann D., Singh S., Beckmann G., Bhatia K., Chen L. Z., Fang B., Lisker R., et al Distribution of ADH2 and ALDH2 genotypes in different populations. Hum. Genet., 88: 344-346, 1992.[Medline]
  45. Yoshida A., Rzhetsky A., Hsu L. C., Chang C. Human aldehyde dehydrogenase gene family. Eur. J. Biochem., 251: 549-557, 1998.[Medline]
  46. Sreerama L., Sladek N. E. Three different stable human breast adenocarcinoma sublines that overexpress ALDH3A1 and certain other enzymes, apparently as a consequence of constitutively upregulated gene transcription mediated by transactivated EpREs (electrophile responsive elements) present in the 5'-upstream regions of these genes. Chem. Biol. Interact., 130–132: 247-260, 2001.
  47. Benedetti M. S., Dostert P. Contribution of amine oxidases to the metabolism of xenobiotics. Drug Metab. Rev., 26: 507-535, 1994.[Medline]
  48. Primiano T., Li Y., Kensler T. W., Trush M. A., Sutter T. R. Identification of dithiolethione-inducible gene-1 as a leukotriene B4 12-hydroxydehydrogenase: implications for chemoprevention. Carcinogenesis (Lond.), 19: 999-1005, 1998.[Abstract/Free Full Text]
  49. Dick R. A., Kwak M. K., Sutter T. R., Kensler T. W. Antioxidative function and substrate specificity of NAD(P)H-dependent alkenal/one oxidoreductase. A new role for leukotriene B4 12- hydroxydehydrogenase/15-oxoprostaglandin 13-reductase. J. Biol. Chem., 276: 40803-40810, 2001.[Abstract/Free Full Text]
  50. Eder E., Hoffman C., Deininger C. Identification and characterization of deoxyguanosine adducts of methyl vinyl ketone and ethyl vinyl ketone. Genotoxicity of the ketones in the SOS Chromotest. Chem. Res. Toxicol., 4: 50-57, 1991.[Medline]
  51. Li J., Lee J. M., Johnson J. A. Microarray analysis reveals an antioxidant responsive element-driven gene set involved in conferring protection from an oxidative stress-induced apoptosis in IMR-32 cells. J. Biol. Chem., 277: 388-394, 2002.[Abstract/Free Full Text]
  52. Chayen J., Howat D. W., Bitensky L. Cellular biochemistry of glucose 6-phosphate and 6-phosphogluconate dehydrogenase activities. Cell Biochem. Funct., 4: 249-253, 1986.[Medline]
  53. Hanukoglu I., Rapoport R. Routes and regulation of NADPH production in steroidogenic mitochondria. Endocr. Res., 21: 231-241, 1995.[Medline]
  54. Kirsch M., De Groot H. NAD(P)H, a directly operating antioxidant?. FASEB J., 15: 1569-1574, 2001.[Abstract/Free Full Text]
  55. Tsuji Y., Ayaki H., Whitman S. P., Morrow C. S., Torti S. V., Torti F. M. Coordinate transcriptional and translational regulation of ferritin in response to oxidative stress. Mol. Cell. Biol., 20: 5818-5827, 2000.[Abstract/Free Full Text]
  56. Fink A. L. Chaperone-mediated protein folding. Physiol. Rev., 79: 425-449, 1999.[Abstract/Free Full Text]
  57. Wassell J. Haptoglobin: function and polymorphism. Clin. Lab., 46: 547-552, 2000.[Medline]
  58. Keppler D., Leier I., Jedlitschky G. Transport of glutathione conjugates and glucuronides by the multidrug resistance proteins MRP1 and MRP2. Biol. Chem., 378: 787-791, 1997.[Medline]
  59. Sarhan S., Knoedgen B., Seiler N. Protection against lethal ammonia intoxication: synergism between endogenous ornithine and L-carnitine. Metab. Brain Dis., 9: 67-79, 1994.[Medline]
  60. Davidson N. E., Egner P. A., Kensler T. W. Transcriptional control of glutathione S-transferase gene expression by the chemoprotective agent 5-(2-pyrazinyl)-4-methyl-1,2-dithiole-3-thione (oltipraz) in rat liver. Cancer Res., 50: 2251-2255, 1990.[Abstract/Free Full Text]
  61. Kensler T. W., Groopman J. D., Sutter T. R., Curphey T. J., Roebuck B. D. Development of cancer chemopreventive agents: oltipraz as a paradigm. Chem. Res. Toxicol., 12: 113-126, 1999.[Medline]



This article has been cited by other articles:


Home page
CarcinogenesisHome page
M. S. Yates, Q. T. Tran, P. M. Dolan, W. O. Osburn, S. Shin, C. C. McCulloch, J. B. Silkworth, K. Taguchi, M. Yamamoto, C. R. Williams, et al.
Genetic versus chemoprotective activation of Nrf2 signaling: overlapping yet distinct gene expression profiles between Keap1 knockout and triterpenoid-treated mice
Carcinogenesis, June 1, 2009; 30(6): 1024 - 1031.
[Abstract] [Full Text] [PDF]


Home page
Drug Metab. Dispos.Home page
D. B. Buckley and C. D. Klaassen
Induction of Mouse UDP-Glucuronosyltransferase mRNA Expression in Liver and Intestine by Activators of Aryl-Hydrocarbon Receptor, Constitutive Androstane Receptor, Pregnane X Receptor, Peroxisome Proliferator-Activated Receptor {alpha}, and Nuclear Factor Erythroid 2-Related Factor 2
Drug Metab. Dispos., April 1, 2009; 37(4): 847 - 856.
[Abstract] [Full Text] [PDF]


Home page
Toxicol SciHome page
S. A. Reisman, R. L. Yeager, M. Yamamoto, and C. D. Klaassen
Increased Nrf2 Activation in Livers from Keap1-Knockdown Mice Increases Expression of Cytoprotective Genes that Detoxify Electrophiles more than those that Detoxify Reactive Oxygen Species
Toxicol. Sci., March 1, 2009; 108(1): 35 - 47.
[Abstract] [Full Text] [PDF]


Home page
J. Immunol.Home page
S. A. Rushworth, D. J. MacEwan, and M. A. O'Connell
Lipopolysaccharide-Induced Expression of NAD(P)H:Quinone Oxidoreductase 1 and Heme Oxygenase-1 Protects against Excessive Inflammatory Responses in Human Monocytes
J. Immunol., November 15, 2008; 181(10): 6730 - 6737.
[Abstract] [Full Text] [PDF]


Home page
Journals of Gerontology Series A: Biological Sciences and Medical SciencesHome page
M. H. Noyan-Ashraf, Z. Sadeghinejad, G. F. Davies, A. R. Ross, D. Saucier, T. A. A. Harkness, and B. H. J. Juurlink
Phase 2 Protein Inducers in the Diet Promote Healthier Aging
J. Gerontol. A Biol. Sci. Med. Sci., November 1, 2008; 63(11): 1168 - 1176.
[Abstract] [Full Text] [PDF]


Home page
Cancer Res.Home page
A. Singh, S. Boldin-Adamsky, R. K. Thimmulappa, S. K. Rath, H. Ashush, J. Coulter, A. Blackford, S. N. Goodman, F. Bunz, W. H. Watson, et al.
RNAi-Mediated Silencing of Nuclear Factor Erythroid-2-Related Factor 2 Gene Expression in Non-Small Cell Lung Cancer Inhibits Tumor Growth and Increases Efficacy of Chemotherapy
Cancer Res., October 1, 2008; 68(19): 7975 - 7984.
[Abstract] [Full Text] [PDF]


Home page
Am. J. Respir. Cell Mol. Bio.Home page
T. L. Adair-Kirk, J. J. Atkinson, G. L. Griffin, M. A. Watson, D. G. Kelley, D. DeMello, R. M. Senior, and T. Betsuyaku
Distal Airways in Mice Exposed to Cigarette Smoke: Nrf2-Regulated Genes Are Increased in Clara Cells
Am. J. Respir. Cell Mol. Biol., October 1, 2008; 39(4): 400 - 411.
[Abstract] [Full Text] [PDF]


Home page
DiabetesHome page
M. Xue, Q. Qian, A. Adaikalakoteswari, N. Rabbani, R. Babaei-Jadidi, and P. J. Thornalley
Activation of NF-E2-Related Factor-2 Reverses Biochemical Dysfunction of Endothelial Cells Induced by Hyperglycemia Linked to Vascular Disease
Diabetes, October 1, 2008; 57(10): 2809 - 2817.
[Abstract] [Full Text] [PDF]


Home page
Am. J. Respir. Crit. Care Med.Home page
D. Malhotra, R. Thimmulappa, A. Navas-Acien, A. Sandford, M. Elliott, A. Singh, L. Chen, X. Zhuang, J. Hogg, P. Pare, et al.
Decline in NRF2-regulated Antioxidants in Chronic Obstructive Pulmonary Disease Lungs Due to Loss of Its Positive Regulator, DJ-1
Am. J. Respir. Crit. Care Med., September 15, 2008; 178(6): 592 - 604.
[Abstract] [Full Text] [PDF]


Home page
Am. J. Respir. Cell Mol. Bio.Home page
K. K. Meja, S. Rajendrasozhan, D. Adenuga, S. K. Biswas, I. K. Sundar, G. Spooner, J. A. Marwick, P. Chakravarty, D. Fletcher, P. Whittaker, et al.
Curcumin Restores Corticosteroid Function in Monocytes Exposed to Oxidants by Maintaining HDAC2
Am. J. Respir. Cell Mol. Biol., September 1, 2008; 39(3): 312 - 323.
[Abstract] [Full Text] [PDF]


Home page
Am. J. Respir. Cell Mol. Bio.Home page
R. L. Rouse, G. Murphy, M. J. Boudreaux, D. B. Paulsen, and A. L. Penn
Soot Nanoparticles Promote Biotransformation, Oxidative Stress, and Inflammation in Murine Lungs
Am. J. Respir. Cell Mol. Biol., August 1, 2008; 39(2): 198 - 207.
[Abstract] [Full Text] [PDF]


Home page
Cancer Res.Home page
L. Mastrangelo, A. Cassidy, F. Mulholland, W. Wang, and Y. Bao
Serotonin Receptors, Novel Targets of Sulforaphane Identified by Proteomic Analysis in Caco-2 Cells
Cancer Res., July 1, 2008; 68(13): 5487 - 5491.
[Abstract] [Full Text] [PDF]


Home page
CarcinogenesisHome page
X.-J. Wang, Z. Sun, N. F. Villeneuve, S. Zhang, F. Zhao, Y. Li, W. Chen, X. Yi, W. Zheng, G. T. Wondrak, et al.
Nrf2 enhances resistance of cancer cells to chemotherapeutic drugs, the dark side of Nrf2
Carcinogenesis, June 1, 2008; 29(6): 1235 - 1243.
[Abstract] [Full Text] [PDF]


Home page
Drug Metab. Dispos.Home page
H. Takakusa, H. Masumoto, A. Mitsuru, O. Okazaki, and K. Sudo
Markers of Electrophilic Stress Caused by Chemically Reactive Metabolites in Human Hepatocytes
Drug Metab. Dispos., May 1, 2008; 36(5): 816 - 823.
[Abstract] [Full Text] [PDF]


Home page
Am. J. Respir. Cell Mol. Bio.Home page
G. Murphy Jr., R. L. Rouse, W. W. Polk, W. G. Henk, S. A. Barker, M. J. Boudreaux, Z. E. Floyd, and A. L. Penn
Combustion-Derived Hydrocarbons Localize to Lipid Droplets in Respiratory Cells
Am. J. Respir. Cell Mol. Biol., May 1, 2008; 38(5): 532 - 540.
[Abstract] [Full Text] [PDF]


Home page
Mol. Cell. ProteomicsHome page
H. Sarioglu, S. Brandner, M. Haberger, C. Jacobsen, J. Lichtmannegger, M. Wormke, and U. Andrae
Analysis of 2,3,7,8-Tetrachlorodibenzo-p-dioxin-induced Proteome Changes in 5L Rat Hepatoma Cells Reveals Novel Targets of Dioxin Action Including the Mitochondrial Apoptosis Regulator VDAC2
Mol. Cell. Proteomics, February 1, 2008; 7(2): 394 - 410.
[Abstract] [Full Text] [PDF]


Home page
StrokeHome page
X. Zhao, G. Sun, J. Zhang, R. Strong, P. K. Dash, Y. W. Kan, J. C. Grotta, and J. Aronowski
Transcription Factor Nrf2 Protects the Brain From Damage Produced by Intracerebral Hemorrhage
Stroke, December 1, 2007; 38(12): 3280 - 3286.
[Abstract] [Full Text] [PDF]


Home page
Physiol. GenomicsHome page
V. Misra, H. Lee, A. Singh, K. Huang, R. K. Thimmulappa, W. Mitzner, S. Biswal, and C. G. Tankersley
Global expression profiles from C57BL/6J and DBA/2J mouse lungs to determine aging-related genes
Physiol Genomics, November 14, 2007; 31(3): 429 - 440.
[Abstract] [Full Text] [PDF]


Home page
Toxicol SciHome page
M. Rokushima, K. Omi, K. Imura, A. Araki, N. Furukawa, F. Itoh, M. Miyazaki, J. Yamamoto, M. Rokushima, M. Okada, et al.
Toxicogenomics of Drug-Induced Hemolytic Anemia by Analyzing Gene Expression Profiles in the Spleen
Toxicol. Sci., November 1, 2007; 100(1): 290 - 302.
[Abstract] [Full Text] [PDF]


Home page
J. Neurosci.Home page
J. Zhao, A. N. Moore, J. B. Redell, and P. K. Dash
Enhancing Expression of Nrf2-Driven Genes Protects the Blood Brain Barrier after Brain Injury
J. Neurosci., September 19, 2007; 27(38): 10240 - 10248.
[Abstract] [Full Text] [PDF]


Home page
J. Biol. Chem.Home page
K. Iwasaki, K. Hailemariam, and Y. Tsuji
PIAS3 Interacts with ATF1 and Regulates the Human Ferritin H Gene through an Antioxidant-responsive Element
J. Biol. Chem., August 3, 2007; 282(31): 22335 - 22343.
[Abstract] [Full Text] [PDF]


Home page
CarcinogenesisHome page
B. S. Cornblatt, L. Ye, A. T. Dinkova-Kostova, M. Erb, J. W. Fahey, N. K. Singh, M.-S. A. Chen, T. Stierer, E. Garrett-Mayer, P. Argani, et al.
Preclinical and clinical evaluation of sulforaphane for chemoprevention in the breast
Carcinogenesis, July 1, 2007; 28(7): 1485 - 1490.
[Abstract] [Full Text] [PDF]


Home page
Toxicol PatholHome page
L. M. Aleksunes and J. E. Manautou
Emerging Role of Nrf2 in Protecting Against Hepatic and Gastrointestinal Disease
Toxicol Pathol, June 1, 2007; 35(4): 459 - 473.
[Abstract] [Full Text] [PDF]


Home page
Clin. Cancer Res.Home page
A. F. Baker, T. Landowski, R. Dorr, W. R. Tate, J. M.C. Gard, B. E. Tavenner, T. Dragovich, A. Coon, and G. Powis
The Antitumor Agent Imexon Activates Antioxidant Gene Expression: Evidence for an Oxidative Stress Response
Clin. Cancer Res., June 1, 2007; 13(11): 3388 - 3394.
[Abstract] [Full Text] [PDF]


Home page
Hum Mol GenetHome page
X. Wang, D. J. Tomso, B. N. Chorley, H.-Y. Cho, V. G. Cheung, S. R. Kleeberger, and D. A. Bell
Identification of polymorphic antioxidant response elements in the human genome
Hum. Mol. Genet., May 15, 2007; 16(10): 1188 - 1200.
[Abstract] [Full Text] [PDF]


Home page
Toxicol SciHome page
S. G. Kim and S. J. Lee
PI3K, RSK, and mTOR Signal Networks for the GST Gene Regulation
Toxicol. Sci., April 1, 2007; 96(2): 206 - 213.
[Abstract] [Full Text] [PDF]


Home page
J. Biol. Chem.Home page
M.-F. Yueh and R. H. Tukey
Nrf2-Keap1 Signaling Pathway Regulates Human UGT1A1 Expression in Vitro and in Transgenic UGT1 Mice
J. Biol. Chem., March 23, 2007; 282(12): 8749 - 8758.
[Abstract] [Full Text] [PDF]


Home page
Am. J. Physiol. Lung Cell. Mol. Physiol.Home page
A. Balbir, H. Lee, M. Okumura, S. Biswal, R. S. Fitzgerald, and M. Shirahata
A search for genes that may confer divergent morphology and function in the carotid body between two strains of mice
Am J Physiol Lung Cell Mol Physiol, March 1, 2007; 292(3): L704 - L715.
[Abstract] [Full Text] [PDF]


Home page
Molecular Cancer TherapeuticsHome page
A. Pledgie-Tracy, M. D. Sobolewski, and N. E. Davidson
Sulforaphane induces cell type-specific apoptosis in human breast cancer cell lines
Mol. Cancer Ther., March 1, 2007; 6(3): 1013 - 1021.
[Abstract] [Full Text] [PDF]


Home page
J. Biol. Chem.Home page
S.-C. Lo and M. Hannink
PGAM5, a Bcl-XL-interacting Protein, Is a Novel Substrate for the Redox-regulated Keap1-dependent Ubiquitin Ligase Complex
J. Biol. Chem., December 8, 2006; 281(49): 37893 - 37903.
[Abstract] [Full Text] [PDF]


Home page
FASEB J.Home page
M. O. Leonard, N. E. Kieran, K. Howell, M. J. Burne, R. Varadarajan, S. Dhakshinamoorthy, A. G. Porter, C. O'Farrelly, H. Rabb, and C. T. Taylor
Reoxygenation-specific activation of the antioxidant transcription factor Nrf2 mediates cytoprotective gene expression in ischemia-reperfusion injury
FASEB J, December 1, 2006; 20(14): 2624 - 2626.
[Abstract] [Full Text] [PDF]


Home page
J. Biol. Chem.Home page
W. Li, S.-W. Yu, and A.-N. T. Kong
Nrf2 Possesses a Redox-sensitive Nuclear Exporting Signal in the Neh5 Transactivation Domain
J. Biol. Chem., September 15, 2006; 281(37): 27251 - 27263.
[Abstract] [Full Text] [PDF]


Home page
J. Immunol.Home page
J. Wan and D. Diaz-Sanchez
Phase II Enzymes Induction Blocks the Enhanced IgE Production in B Cells by Diesel Exhaust Particles.
J. Immunol., September 1, 2006; 177(5): 3477 - 3483.
[Abstract] [Full Text] [PDF]


Home page
J. Exp. Biol.Home page
C. Goldring, N. Kitteringham, R. Jenkins, I. Copple, J.-F. Jeannin, and B. K. Park
Plasticity in cell defence: access to and reactivity of critical protein residues and DNA response elements
J. Exp. Biol., June 15, 2006; 209(12): 2337 - 2343.
[Abstract] [Full Text] [PDF]


Home page
Mol. Pharmacol.Home page
H. Lou, S. Du, Q. Ji, and A. Stolz
Induction of AKR1C2 by Phase II Inducers: Identification of a Distal Consensus Antioxidant Response Element Regulated by NRF2
Mol. Pharmacol., May 1, 2006; 69(5): 1662 - 1672.
[Abstract] [Full Text] [PDF]


Home page
Am. J. Physiol. Heart Circ. Physiol.Home page
X.-L. Chen, G. Dodd, S. Thomas, X. Zhang, M. A. Wasserman, B. H. Rovin, and C. Kunsch
Activation of Nrf2/ARE pathway protects endothelial cells from oxidant injury and inhibits inflammatory gene expression
Am J Physiol Heart Circ Physiol, May 1, 2006; 290(5): H1862 - H1870.
[Abstract] [Full Text] [PDF]


Home page
CarcinogenesisHome page
M. C. Myzak, K. Hardin, R. Wang, R. H. Dashwood, and E. Ho
Sulforaphane inhibits histone deacetylase activity in BPH-1, LnCaP and PC-3 prostate epithelial cells
Carcinogenesis, April 1, 2006; 27(4): 811 - 819.
[Abstract] [Full Text] [PDF]


Home page
Toxicol SciHome page
T. Umemura, Y. Kuroiwa, Y. Kitamura, Y. Ishii, K. Kanki, Y. Kodama, K. Itoh, M. Yamamoto, A. Nishikawa, and M. Hirose
A Crucial Role of Nrf2 in In Vivo Defense against Oxidative Damage by an Environmental Pollutant, Pentachlorophenol
Toxicol. Sci., March 1, 2006; 90(1): 111 - 119.
[Abstract] [Full Text] [PDF]


Home page
Molecular Cancer TherapeuticsHome page
G. Shen, C. Xu, R. Hu, M. R. Jain, A. Gopalkrishnan, S. Nair, M.-T. Huang, J. Y. Chan, and A.-N. T. Kong
Modulation of nuclear factor E2-related factor 2-mediated gene expression in mice liver and small intestine by cancer chemopreventive agent curcumin
Mol. Cancer Ther., January 1, 2006; 5(1): 39 - 51.
[Abstract] [Full Text] [PDF]


Home page
CarcinogenesisHome page
C.-T. Yeh and G.-C. Yen
Effect of sulforaphane on metallothionein expression and induction of apoptosis in human hepatoma HepG2 cells
Carcinogenesis, December 1, 2005; 26(12): 2138 - 2148.
[Abstract] [Full Text] [PDF]


Home page
J. Nutr.Home page
Y.-J. Surh, J. K. Kundu, H.-K. Na, and J.-S. Lee
Redox-Sensitive Transcription Factors as Prime Targets for Chemoprevention with Anti-Inflammatory and Antioxidative Phytochemicals
J. Nutr., December 1, 2005; 135(12): 2993S - 3001S.
[Abstract] [Full Text] [PDF]


Home page
J. Neurosci.Home page
A. Y. Shih, P. Li, and T. H. Murphy
A Small-Molecule-Inducible Nrf2-Mediated Antioxidant Response Provides Effective Prophylaxis against Cerebral Ischemia In Vivo
J. Neurosci., November 2, 2005; 25(44): 10321 - 10335.
[Abstract] [Full Text] [PDF]


Home page
Cancer Epidemiol. Biomarkers Prev.Home page
T. W. Kensler, J.-G. Chen, P. A. Egner, J. W. Fahey, L. P. Jacobson, K. K. Stephenson, L. Ye, J. L. Coady, J.-B. Wang, Y. Wu, et al.
Effects of Glucosinolate-Rich Broccoli Sprouts on Urinary Levels of Aflatoxin-DNA Adducts and Phenanthrene Tetraols in a Randomized Clinical Trial in He Zuo Township, Qidong, People's Republic of China
Cancer Epidemiol. Biomarkers Prev., November 1, 2005; 14(11): 2605 - 2613.
[Abstract] [Full Text] [PDF]


Home page
Proc. Natl. Acad. Sci. USAHome page
K. J. Hintze and E. C. Theil
DNA and mRNA elements with complementary responses to hemin, antioxidant inducers, and iron control ferritin-L expression
PNAS, October 18, 2005; 102(42): 15048 - 15052.
[Abstract] [Full Text] [PDF]


Home page
J. Immunol.Home page
H.-J. Kim and A. E. Nel
The Role of Phase II Antioxidant Enzymes in Protecting Memory T Cells from Spontaneous Apoptosis in Young and Old Mice
J. Immunol., September 1, 2005; 175(5): 2948 - 2959.
[Abstract] [Full Text] [PDF]


Home page
J. Biol. Chem.Home page
D. D. Zhang, S.-C. Lo, Z. Sun, G. M. Habib, M. W. Lieberman, and M. Hannink
Ubiquitination of Keap1, a BTB-Kelch Substrate Adaptor Protein for Cul3, Targets Keap1 for Degradation by a Proteasome-independent Pathway
J. Biol. Chem., August 26, 2005; 280(34): 30091 - 30099.
[Abstract] [Full Text] [PDF]


Home page
J. Biol. Chem.Home page
W. Li, M. R. Jain, C. Chen, X. Yue, V. Hebbar, R. Zhou, and A.-N. T. Kong
Nrf2 Possesses a Redox-insensitive Nuclear Export Signal Overlapping with the Leucine Zipper Motif
J. Biol. Chem., August 5, 2005; 280(31): 28430 - 28438.
[Abstract] [Full Text] [PDF]


Home page
J. Nutr.Home page
M. Traka, A. V. Gasper, J. A. Smith, C. J. Hawkey, Y. Bao, and R. F. Mithen
Transcriptome Analysis of Human Colon Caco-2 Cells Exposed to Sulforaphane
J. Nutr., August 1, 2005; 135(8): 1865 - 1872.
[Abstract] [Full Text] [PDF]


Home page
J. Biol. Chem.Home page
R. Feng, Y. Lu, L. L. Bowman, Y. Qian, V. Castranova, and M. Ding
Inhibition of Activator Protein-1, NF-{kappa}B, and MAPKs and Induction of Phase 2 Detoxifying Enzyme Activity by Chlorogenic Acid
J. Biol. Chem., July 29, 2005; 280(30): 27888 - 27895.
[Abstract] [Full Text] [PDF]


Home page
FASEB J.Home page
J.-M. Lee, J. Li, D. A. Johnson, T. D. Stein, A. D. Kraft, M. J. Calkins, R. J. Jakel, and J. A. Johnson
Nrf2, a multi-organ protector?
FASEB J, July 1, 2005; 19(9): 1061 - 1066.
[Abstract] [Full Text] [PDF]


Home page
BrainHome page
J. Kirby, E. Halligan, M. J. Baptista, S. Allen, P. R. Heath, H. Holden, S. C. Barber, C. A. Loynes, C. A. Wood-Allum, J. Lunec, et al.
Mutant SOD1 alters the motor neuronal transcriptome: implications for familial ALS
Brain, July 1, 2005; 128(7): 1686 - 1706.
[Abstract] [Full Text] [PDF]


Home page
CarcinogenesisHome page
J. W. Fahey, K. K. Stephenson, A. T. Dinkova-Kostova, P. A. Egner, T. W. Kensler, and P. Talalay
Chlorophyll, chlorophyllin and related tetrapyrroles are significant inducers of mammalian phase 2 cytoprotective genes
Carcinogenesis, July 1, 2005; 26(7): 1247 - 1255.
[Abstract] [Full Text] [PDF]


Home page
J. Biol. Chem.Home page
A. Y. Shih, S. Imbeault, V. Barakauskas, H. Erb, L. Jiang, P. Li, and T. H. Murphy
Induction of the Nrf2-driven Antioxidant Response Confers Neuroprotection during Mitochondrial Stress in Vivo
J. Biol. Chem., June 17, 2005; 280(24): 22925 - 22936.
[Abstract] [Full Text] [PDF]


Home page
Cancer Res.Home page
K. Liby, T. Hock, M. M. Yore, N. Suh, A. E. Place, R. Risingsong, C. R. Williams, D. B. Royce, T. Honda, Y. Honda, et al.
The Synthetic Triterpenoids, CDDO and CDDO-Imidazolide, Are Potent Inducers of Heme Oxygenase-1 and Nrf2/ARE Signaling
Cancer Res., June 1, 2005; 65(11): 4789 - 4798.
[Abstract] [Full Text] [PDF]


Home page
Molecular Cancer TherapeuticsHome page
A. G. Banerjee, I. Bhattacharyya, and J. K. Vishwanatha
Identification of genes and molecular pathways involved in the progression of premalignant oral epithelia
Mol. Cancer Ther., June 1, 2005; 4(6): 865 - 875.
[Abstract] [Full Text] [PDF]


Home page
Mol. Cell. Biol.Home page
S. H. Ki, I. J. Cho, D. W. Choi, and S. G. Kim
Glucocorticoid Receptor (GR)-Associated SMRT Binding to C/EBP{beta} TAD and Nrf2 Neh4/5: Role of SMRT Recruited to GR in GSTA2 Gene Repression
Mol. Cell. Biol., May 15, 2005; 25(10): 4150 - 4165.
[Abstract] [Full Text] [PDF]


Home page
J. Biol. Chem.Home page
H. Chen, E. Rubin, H. Zhang, S. Chung, C. C. Jie, E. Garrett, S. Biswal, and S. Sukumar
Identification of Transcriptional Targets of HOXA5
J. Biol. Chem., May 13, 2005; 280(19): 19373 - 19380.
[Abstract] [Full Text] [PDF]


Home page
Physiol. GenomicsHome page
J. Li, M. L. Spletter, and J. A. Johnson
Dissecting tBHQ induced ARE-driven gene expression through long and short oligonucleotide arrays
Physiol Genomics, March 21, 2005; 21(1): 43 - 58.
[Abstract] [Full Text] [PDF]


Home page
Proc. Natl. Acad. Sci. USAHome page
M. J. Calkins, R. J. Jakel, D. A. Johnson, K. Chan, Y. W. Kan, and J. A. Johnson
Protection from mitochondrial complex II inhibition in vitro and in vivo by Nrf2-mediated transcription
PNAS, January 4, 2005; 102(1): 244 - 249.
[Abstract] [Full Text] [PDF]


Home page
Mol. Cell. Biol.Home page
D. D. Zhang, S.-C. Lo, J. V. Cross, D. J. Templeton, and M. Hannink
Keap1 Is a Redox-Regulated Substrate Adaptor Protein for a Cul3-Dependent Ubiquitin Ligase Complex
Mol. Cell. Biol., December 15, 2004; 24(24): 10941 - 10953.
[Abstract] [Full Text] [PDF]


Home page
J. Nutr.Home page
G. K. McWalter, L. G. Higgins, L. I. McLellan, C. J. Henderson, L. Song, P. J. Thornalley, K. Itoh, M. Yamamoto, and J. D. Hayes
Transcription Factor Nrf2 Is Essential for Induction of NAD(P)H:Quinone Oxidoreductase 1, Glutathione S-Transferases, and Glutamate Cysteine Ligase by Broccoli Seeds and Isothiocyanates
J. Nutr., December 1, 2004; 134(12): 3499S - 3506S.
[Abstract] [Full Text] [PDF]


Home page
J AndrolHome page
W. Li, H. Amri, H. Huang, C. Wu, and V. Papadopoulos
Gene and Protein Profiling of the Response of MA-10 Leydig Tumor Cells to Human Chorionic Gonadotropin
J Androl, November 1, 2004; 25(6): 900 - 913.
[Abstract] [Full Text] [PDF]


Home page
Cancer Res.Home page
I. Bae, S. Fan, Q. Meng, J. K. Rih, H. J. Kim, H. J. Kang, J. Xu, I. D. Goldberg, A. K. Jaiswal, and E. M. Rosen
BRCA1 Induces Antioxidant Gene Expression and Resistance to Oxidative Stress
Cancer Res., November 1, 2004; 64(21): 7893 - 7909.
[Abstract] [Full Text] [PDF]


Home page
J. Immunol.Home page
N. Li, J. Alam, M. I. Venkatesan, A. Eiguren-Fernandez, D. Schmitz, E. Di Stefano, N. Slaughter, E. Killeen, X. Wang, A. Huang, et al.
Nrf2 Is a Key Transcription Factor That Regulates Antioxidant Defense in Macrophages and Epithelial Cells: Protecting against the Proinflammatory and Oxidizing Effects of Diesel Exhaust Chemicals
J. Immunol., September 1, 2004; 173(5): 3467 - 3481.
[Abstract] [Full Text] [PDF]


Home page
CarcinogenesisHome page
V. Svehlikova, S. Wang, J. Jakubikova, G. Williamson, R. Mithen, and Y. Bao
Interactions between sulforaphane and apigenin in the induction of UGT1A1 and GSTA1 in CaCo-2 cells
Carcinogenesis, September 1, 2004; 25(9): 1629 - 1637.
[Abstract] [Full Text] [PDF]


Home page
Cancer Res.Home page
M. C. Myzak, P. A. Karplus, F.-L. Chung, and R. H. Dashwood
A Novel Mechanism of Chemoprotection by Sulforaphane: Inhibition of Histone Deacetylase
Cancer Res., August 15, 2004; 64(16): 5767 - 5774.
[Abstract] [Full Text] [PDF]


Home page
J. Pharmacol. Exp. Ther.Home page
R. Hu, V. Hebbar, B.-R. Kim, C. Chen, B. Winnik, B. Buckley, P. Soteropoulos, P. Tolias, R. P. Hart, and A.-N. T. Kong
In Vivo Pharmacokinetics and Regulation of Gene Expression Profiles by Isothiocyanate Sulforaphane in the Rat
J. Pharmacol. Exp. Ther., July 1, 2004; 310(1): 263 - 271.
[Abstract] [Full Text] [PDF]


Home page
GENES CELLSHome page
T. Yanagawa, K. Itoh, J. Uwayama, Y. Shibata, A. Yamaguchi, T. Sano, T. Ishii, H. Yoshida, and M. Yamamoto
Nrf2 deficiency causes tooth decolourization due to iron transport disorder in enamel organ
Genes Cells, July 1, 2004; 9(7): 641 - 651.
[Abstract] [Full Text] [PDF]


Home page
Molecular Cancer TherapeuticsHome page
Y. Zhang and G. B. Gordon
A strategy for cancer prevention: Stimulation of the Nrf2-ARE signaling pathway
Mol. Cancer Ther., July 1, 2004; 3(7): 885 - 893.
[Abstract] [Full Text] [PDF]


Home page
Proc. Natl. Acad. Sci. USAHome page
J.-M. Lee, K. Chan, Y. W. Kan, and J. A. Johnson
Targeted disruption of Nrf2 causes regenerative immune-mediated hemolytic anemia
PNAS, June 29, 2004; 101(26): 9751 - 9756.
[Abstract] [Full Text] [PDF]


Home page
J. Biol. Chem.Home page
S. V. Singh, A. Herman-Antosiewicz, A. V. Singh, K. L. Lew, S. K. Srivastava, R. Kamath, K. D. Brown, L. Zhang, and R. Baskaran
Sulforaphane-induced G2/M Phase Cell Cycle Arrest Involves Checkpoint Kinase 2-mediated Phosphorylation of Cell Division Cycle 25C
J. Biol. Chem., June 11, 2004; 279(24): 25813 - 25822.
[Abstract] [Full Text] [PDF]


Home page
Toxicol SciHome page
W. H. M. Heijne, A. L. Slitt, P. J. van Bladeren, J. P. Groten, C. D. Klaassen, R. H. Stierum, and B. van Ommen
Bromobenzene-Induced Hepatotoxicity at the Transcriptome Level
Toxicol. Sci., June 1, 2004; 79(2): 411 - 422.
[Abstract] [Full Text] [PDF]


Home page
J. Biol. Chem.Home page
B. G. Petrich, B. C. Eloff, D. L. Lerner, A. Kovacs, J. E. Saffitz, D. S. Rosenbaum, and Y. Wang
Targeted Activation of c-Jun N-terminal Kinase in Vivo Induces Restrictive Cardiomyopathy and Conduction Defects
J. Biol. Chem., April 9, 2004; 279(15): 15330 - 15338.
[Abstract] [Full Text] [PDF]


Home page
CarcinogenesisHome page
S. Gebel, B. Gerstmayer, A. Bosio, H.-J. Haussmann, E. V. Miert, and T. Muller
Gene expression profiling in respiratory tissues from rats exposed to mainstream cigarette smoke
Carcinogenesis, February 1, 2004; 25(2): 169 - 178.
[Abstract] [Full Text] [PDF]


Home page
CarcinogenesisHome page
A. V. Singh, D. Xiao, K. L. Lew, R. Dhir, and S. V. Singh
Sulforaphane induces caspase-mediated apoptosis in cultured PC-3 human prostate cancer cells and retards growth of PC-3 xenografts in vivo
Carcinogenesis, January 1, 2004; 25(1): 83 - 90.
[Abstract] [Full Text] [PDF]


Home page
Mol. Cell. Biol.Home page
M.-K. Kwak, N. Wakabayashi, J. L. Greenlaw, M. Yamamoto, and T. W. Kensler
Antioxidants Enhance Mammalian Proteasome Expression through the Keap1-Nrf2 Signaling Pathway
Mol. Cell. Biol., December 1, 2003; 23(23): 8786 - 8794.
[Abstract] [Full Text] [PDF]


Home page
Mol. Cell. Biol.Home page
D. D. Zhang and M. Hannink
Distinct Cysteine Residues in Keap1 Are Required for Keap1-Dependent Ubiquitination of Nrf2 and for Stabilization of Nrf2 by Chemopreventive Agents and Oxidative Stress
Mol. Cell. Biol., November 15, 2003; 23(22): 8137 - 8151.
[Abstract] [Full Text] [PDF]


Home page
Mol. Pharmacol.Home page
I. R. Jowsey, Q. Jiang, K. Itoh, M. Yamamoto, and J. D. Hayes
Expression of the Aflatoxin B1-8,9-Epoxide-Metabolizing Murine Glutathione S-Transferase A3 Subunit Is Regulated by the Nrf2 Transcription Factor through an Antioxidant Response Element
Mol. Pharmacol., November 1, 2003; 64(5): 1018 - 1028.
[Abstract] [Full Text] [PDF]


Home page
Nucleic Acids ResHome page
S. A. Haas, M. Hild, A. P. H. Wright, T. Hain, D. Talibi, and M. Vingron
Genome-scale design of PCR primers and long oligomers for DNA microarrays
Nucleic Acids Res., October 1, 2003; 31(19): 5576 - 5581.
[Abstract] [Full Text] [PDF]


Home page
CarcinogenesisHome page
E.M.J. van der Logt, H.M.J. Roelofs, F.M. Nagengast, and W.H.M. Peters
Induction of rat hepatic and intestinal UDP-glucuronosyltransferases by naturally occurring dietary anticarcinogens
Carcinogenesis, October 1, 2003; 24(10): 1651 - 1656.
[Abstract] [Full Text] [PDF]


Home page
J. Biol. Chem.Home page
J.-M. Lee, A. Y. Shih, T. H. Murphy, and J. A. Johnson
NF-E2-related Factor-2 Mediates Neuroprotection against Mitochondrial Complex I Inhibitors and Increased Concentrations of Intracellular Calcium in Primary Cortical Neurons
J. Biol. Chem., September 26, 2003; 278(39): 37948 - 37956.
[Abstract] [Full Text] [PDF]


Home page
J. Nutr.Home page
K. J. Hintze, K. A. Wald, H. Zeng, E. H. Jeffery, and J. W. Finley
Thioredoxin Reductase in Human Hepatoma Cells Is Transcriptionally Regulated by Sulforaphane and Other Electrophiles via an Antioxidant Response Element-
J. Nutr., September 1, 2003; 133(9): 2721 - 2727.
[Abstract] [Full Text] [PDF]


Home page
Am. J. Respir. Cell Mol. Bio.Home page
S. Srisuma, S. S. Biswal, W. A. Mitzner, S. J. Gallagher, K. H. Mai, and E. M. Wagner
Identification of Genes Promoting Angiogenesis in Mouse Lung by Transcriptional Profiling
Am. J. Respir. Cell Mol. Biol., August 1, 2003; 29(2): 172 - 179.
[Abstract] [Full Text] [PDF]


Home page
Genes Dev.Home page
J. H. An and T. K. Blackwell
SKN-1 links C. elegans mesendodermal specification to a conserved oxidative stress response
Genes & Dev., August 1, 2003; 17(15): 1882 - 1893.
[Abstract] [Full Text] [PDF]


Home page
J. Biol. Chem.Home page
M. McMahon, K. Itoh, M. Yamamoto, and J. D. Hayes
Keap1-dependent Proteasomal Degradation of Transcription Factor Nrf2 Contributes to the Negative Regulation of Antioxidant Response Element-driven Gene Expression
J. Biol. Chem., June 6, 2003; 278(24): 21592 - 21600.
[Abstract] [Full Text] [PDF]


Home page
J. Neurosci.Home page
A. Y. Shih, D. A. Johnson, G. Wong, A. D. Kraft, L. Jiang, H. Erb, J. A. Johnson, and T. H. Murphy
Coordinate Regulation of Glutathione Biosynthesis and Release by Nrf2-Expressing Glia Potently Protects Neurons from Oxidative Stress
J. Neurosci., April 15, 2003; 23(8): 3394 - 3406.
[Abstract] [Full Text] [PDF]


Home page
CarcinogenesisHome page
E. M. Ellis, C. M. Slattery, and J. D. Hayes
Characterization of the rat aflatoxin B1 aldehyde reductase gene, AKR7A1. Structure and chromosomal localization of AKR7A1 as well as identification of antioxidant response elements in the gene promoter
Carcinogenesis, April 1, 2003; 24(4): 727 - 737.
[Abstract] [Full Text] [PDF]


Home page
J. Biol. Chem.Home page
J.-M. Lee, M. J. Calkins, K. Chan, Y. W. Kan, and J. A. Johnson
Identification of the NF-E2-related Factor-2-dependent Genes Conferring Protection against Oxidative Stress in Primary Cortical Astrocytes Using Oligonucleotide Microarray Analysis
J. Biol. Chem., March 28, 2003; 278(14): 12029 - 12038.
[Abstract] [Full Text] [PDF]


Home page
J. Biol. Chem.Home page
M.-K. Kwak, N. Wakabayashi, K. Itoh, H. Motohashi, M. Yamamoto, and T. W. Kensler
Modulation of Gene Expression by Cancer Chemopreventive Dithiolethiones through the Keap1-Nrf2 Pathway. IDENTIFICATION OF NOVEL GENE CLUSTERS FOR CELL SURVIVAL
J. Biol. Chem., February 28, 2003; 278(10): 8135 - 8145.
[Abstract] [Full Text] [PDF]


Home page
J. Biol. Chem.Home page
S. Allen, P. R. Heath, J. Kirby, S. B. Wharton, M. R. Cookson, F. M. Menzies, R. E. Banks, and P. J. Shaw
Analysis of the Cytosolic Proteome in a Cell Culture Model of Familial Amyotrophic Lateral Sclerosis Reveals Alterations to the Proteasome, Antioxidant Defenses, and Nitric Oxide Synthetic Pathways
J. Biol. Chem., February 14, 2003; 278(8): 6371 - 6383.
[Abstract] [Full Text] [PDF]


Home page
J. Biol. Chem.Home page
E. C. Pietsch, J. Y. Chan, F. M. Torti, and S. V. Torti
Nrf2 Mediates the Induction of Ferritin H in Response to Xenobiotics and Cancer Chemopreventive Dithiolethiones
J. Biol. Chem., January 17, 2003; 278(4): 2361 - 2369.
[Abstract] [Full Text] [PDF]


This Article
Right arrow Abstract Freely available
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Thimmulappa, R. K.
Right arrow Articles by Biswal, S.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Thimmulappa, R. K.
Right arrow Articles by Biswal, S.


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Cancer Research Clinical Cancer Research
Cancer Epidemiology Biomarkers & Prevention Molecular Cancer Therapeutics
Molecular Cancer Research Cancer Prevention Research
Cancer Prevention Journals Portal Cancer Reviews Online
Annual Meeting Education Book Meeting Abstracts Online