Apiaceous vegetable intake modulates expression of DNA damage response genes and microRNA in the rat colon
Graphical abstract
Introduction
Multiple epidemiologic studies indicate that high intake of animal fat and meat is associated with an increased risk of colorectal cancer (Chan et al., 2011, Larsson and Wolk, 2006). This positive association between meat consumption and colorectal cancer risk may be due to dietary carcinogens [e.g., heterocyclic aromatic amines (HAA)] produced during cooking of meat at high temperatures (Knize et al., 1999, Sinha et al., 1998). Of the identified HAA, 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) often occurs in the highest concentration in meat (Becher et al., 1988, Ni et al., 2008). PhIP becomes carcinogenic through sequential activation steps: hydroxylation of the exocyclic amine of PhIP by cytochrome P450 (CYP; primarily hepatic CYP1A2) (Zhao, Murray, Davies, Boobis, & Gooderham, 1994) followed by esterification by N-acetyltransferase 2 and sulfotransferase 1A1. The esterified PhIP metabolites form PhIP-DNA adducts through formation of a nitrenium ion (Buonarati et al., 1990, Hein et al., 1994, Muckel et al., 2002). DNA structural damage, as a result of DNA adduct formation by a carcinogen such as activated PhIP, is an early and essential event in the carcinogenic process (Poirier, 2004).
As opposed to a high intake of meats, a diet rich in fruits and vegetables may prevent certain cancers, and one of their chemopreventive mechanisms relates to modulation of phase I and phase II biotransformation enzymes (Saracino & Lampe, 2007). In particular, apiaceous vegetables and their furanocoumarins inhibit procarcinogen activating enzymes (e.g., CYP1A2) (Kang et al., 2011, Lampe et al., 2000). Thus, it was postulated that apiaceous vegetables may lower DNA adduct formation through the suppression of procarcinogen activating enzyme activity. In our recent study, however, feeding apiaceous vegetables (celery and parsnip) in an amount easily achievable by humans reduced PhIP-DNA adducts in rat colon without a concomitant inhibition of CYP1A1 and CYP1A2 activities. These results suggest that there are different mechanisms by which apiaceous vegetables may have reduced adducts (Kim, Gallaher, Chen, Yao, & Trudo, 2015).
Our previous analysis of urinary metabolites of PhIP indicated that methylation is a major metabolic pathway for PhIP, and that apiaceous vegetable intake increased these methylated metabolites. Further, the quantity of methylated PhIP metabolites was negatively correlated with colonic PhIP-DNA adducts (Kim et al., 2015). These observations suggest that apiaceous vegetable intake may have modulated imidazole N-methyltransferase (INMT; also known as histamine N-methyltransferase), the enzyme responsible for methylation of PhIP metabolites. The effect of diet on INMT has not been widely investigated with regards to its significance in carcinogen metabolism. Further, additional mechanisms may have been influenced as well. There is evidence that several constituents (e.g., quercetin and apigenin) found in apiaceous vegetables modulate gene expression of PhIP transporters [e.g., multidrug resistance-associated protein 2; (MRP2)], thereby facilitating PhIP excretion (Bock, Eckle, Ouzzine, & Fournel-Gigleux, 2000). Further, DNA damage response genes (Charles et al., 2012), microRNA (miRNA) related to tumor suppression [e.g., p53 (Shah, Davidson, & Chapkin, 2012)], and zinc finger binding protein 10 (Li et al., 2014)] might be influenced by active constituents of apiaceous vegetables. However, most of these studies examined the effect of single putative bioactive compounds in cell culture, and thus are difficult to translate to the human situation. Therefore, we investigated here effects of apiaceous vegetables on promising protective mechanisms against PhIP mutagenicity utilizing an identical study design to our previous study that demonstrated reduced PhIP-DNA adducts with apiaceous vegetable feeding, including the same dietary concentration of the vegetables (Kim et al., 2015).
Section snippets
Animals
A total of 18 male Wistar rats (100–125 g body wt; Harlan Laboratories, Indianapolis, IN, USA) were housed separately in wire-bottom stainless steel cages. Animals were adapted to a purified diet (AIN-93G) for the first five days and fed ad libitum. Animal handling procedures followed the National Institutes of Health guidelines and the protocol was approved by the University of Minnesota Animal Care and Use Committee (Approval ID: 1403-31424A).
Study diets and design
Rats were assigned to one of three experimental
Food intake, colon and liver weights, and body weight gain
Food intake for API was greater than POS (23.2 ± 0.41 g/d vs. 17.5 ± 0.77 g/d; P = 0.001). However, food intake expressed on a dry weight basis for API (19.2 ± 0.52 g/d) did not differ significantly from food intake for either POS or NEG (P = 0.19). No difference in food intake was shown between POS and NEG (17.5 ± 0.77 g/d vs. 18.2 ± 0.71 g/d; P = 0.48). There were no differences in body weight gain or liver and colon tissue weights among the groups (data not shown).
Measurement of hepatic INMT protein expression
Protein expression of
Discussion
Previously, it was postulated that apiaceous vegetables may lower DNA adduct formation through the suppression of procarcinogen activating enzymes (Kang et al., 2011, Lampe et al., 2000). Our recent study, however, did not support this hypothesis, as apiaceous vegetable feeding (celery and parsnip) at a modest dose, one easily achievable by humans, reduced PhIP-DNA adducts in rat colon without concomitant inhibition of procarcinogen activating enzymes [i.e., CYP1A1 and CYP1A2 activities (Kim et
Conclusion
In conclusion, we have demonstrated that in rats fed fresh apiaceous vegetables at a level achievable in the human diet (i.e., approximately 1 cup of fresh vegetables per day) colonic miRNAs are modulated, several of which are predicted to target genes related to carcinogenesis. In particular, the API diet increased miR-19a that is predicted to reduce expression of a cell cycle-related oncogene (i.e., Ccnd1). Further, there was a trend of increased P-gp with API, which may be due, in part, to
Acknowledgements
This work was supported by the Masonic Cancer Center, University of Minnesota. S.P.T. and D.D.G. designed the research; J.K.K. and S.P.T. conducted the research and analyzed the data; J.K.K., D.D.G., and S.P.T. drafted the manuscript and approved the final content. We would like to thank Dr. Xiaoli Chen and the University of Minnesota Genomics Center for expert guidance and resources. The authors have no conflicts of interest to disclose.
References (48)
- et al.
Modulation of the activity of ABC transporters (P-glycoprotein, MRP2, BCRP) by flavonoids and drug response
Journal of Pharmaceutical Sciences
(2010) - et al.
Coordinate induction by antioxidants of UDP-glucuronosyltransferase UGT1A6 and the apical conjugate export pump MRP2 (multidrug resistance protein 2) in Caco-2 cells
Biochemical Pharmacology
(2000) - et al.
Role of sulfation and acetylation in the activation of 2-hydroxyamino-1-methyl-6-phenylimidazo[4,5-b]pyridine to intermediates which bind DNA
Mutation Research
(1990) - et al.
Measurement of the influence of flavonoids on DNA repair kinetics using the comet assay
Food Chemistry
(2012) - et al.
Elevated circulating miR-150 and miR-342-3p in patients with irritable bowel syndrome
Experimental and Molecular Pathology
(2014) - et al.
Delay of DNA-adduct repair and severe toxicity in xeroderma pigmentosum group A gene (XPA) deficient mice treated with 2-amino-1-methyl-6-phenyl-imidazo [4,5-b] pyridine (PhIP)
Cancer Letters
(2000) - et al.
Regulation of multidrug resistance-associated protein 2 (ABCC2) by the nuclear receptors pregnane X receptor, farnesoid X-activated receptor, and constitutive androstane receptor
Journal of Biological Chemistry
(2002) - et al.
Apiaceous vegetable consumption decreases PhIP-induced DNA adducts and increases methylated PhIP metabolites in the urine metabolome in rats
Journal of Nutrition
(2015) - et al.
Dietary Chlorella protects against heterocyclic amine-induced aberrant gene expression in the rat colon by increasing fecal excretion of unmetabolized PhIP
Food and Chemical Toxicology
(2013) - et al.
Heterologous expression of human N-acetyltransferases 1 and 2 and sulfotransferase 1A1 in Salmonella typhimurium for mutagenicity testing of heterocyclic amines
Food and Chemical Toxicology
(2002)
AIN-93 purified diets for laboratory rodents: final report of the American Institute of Nutrition ad hoc writing committee on the reformulation of the AIN-76A rodent diet
J Nutr
Kinases that control the cell cycle in response to DNA damage: Chk1, Chk2, and MK2
Current Opinion in Cell Biology
Pregnane X receptor mediates the induction of P-glycoprotein by spironolactone in HepG2 cells
Toxicology
Heterocyclic amine content of pork products cooked by different methods and to varying degrees of doneness
Food and Chemical Toxicology
Isolation and identification of mutagens from a fried Norwegian meat product
Carcinogenesis
Effect of maturity, processing, and storage on the furanocoumarin composition of grapefruit and grapefruit juice
Journal of Food Science
Red and processed meat and colorectal cancer incidence: Meta-analysis of prospective studies
PLoS One
A cross comparison of technologies for the detection of microRNAs in clinical FFPE samples of hepatoblastoma patients
Scientific Reports
Noncompetitive inhibition of indolethylamine-N-methyltransferase by N,N-dimethyltryptamine and N,N-dimethylaminopropyltryptamine
Biochemistry
Expression of the multidrug resistance gene product (P-glycoprotein) in human normal and tumor tissues
Journal of Histochemistry and Cytochemistry
Mrp2-deficiency in the rat impairs biliary and intestinal excretion and influences metabolism and disposition of the food-derived carcinogen 2-amino-1-methyl-6-phenylimidazo
Carcinogenesis
Minireview: Cyclin D1: Normal and abnormal functions
Endocrinology
DNA repair: Dynamic defenders against cancer and aging
PLoS Biology
Direct multiplexed measurement of gene expression with color-coded probe pairs
Nature Biotechnology
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Grape seed extract ameliorates PhIP-induced colonic injury by modulating gut microbiota, lipid metabolism, and NF-κB signaling pathway in rats
2021, Journal of Functional FoodsCitation Excerpt :PhIP, one of the most abundant HCAs, is a recognized carcinogen that can induce DNA damage and cell damage, and its long-term intake may result in cancer development (Sugimura et al., 2004). Published studies have shown that antioxidant substances such as curcumin and tocopherol can reduce the cellular damage caused by PhIP (Jain et al., 2015; Kim, Gallaher, & Trudo, 2018). This study indicated that dietary supplementation with GSE remarkably ameliorated oxidative stress and colonic DNA damage induced by PhIP, and proved that GSE protected the colon from PhIP-induced damage by regulating intestinal flora, NF-κB signaling pathway and lipid metabolism.
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Present address: School of Human Environmental Sciences, University of Arkansas, Fayetteville, AR 72701, USA.