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Saw C.L.L.,Center for Cancer Prevention Research | Saw C.L.L.,Rutgers University | Huang Y.,Rutgers University | Kong A.-N.,Center for Cancer Prevention Research | Kong A.-N.,Rutgers University
Biochemical Pharmacology | Year: 2010

Inflammatory response plays an important role not only in the normal physiology but also in the pathology such as cancers. As chronic inflammations are associated with malignancies, it is important to prevent inflammation-mediated neoplastic formation, promotion and/or progression. One possible intervention will be using cancer chemopreventive agents such as curcumin (CUR), a potent anti-inflammatory and anti-oxidative stress compound. Polyunsaturated fatty acids (PUFA) such as docosahexaenoic acid (DHA) or eicosapentaenoic acid (EPA) are potent anti-inflammatory agents by decreasing the production of inflammatory eicosanoids, cytokines, and reactive oxygen species (ROS). The present study aims at examining whether CUR with DHA or EPA would have synergistic anti-inflammatory effects in RAW 264.7 cells. Non-toxic concentrations of single and combination of the compounds were investigated at 6, 12 and 24 h. The nitric oxide (NO) suppression effects were most prominent at 24 h. All the combinations of CUR and DHA or EPA with lower concentrations of CUR 5 μM and 25 μM of DHA or EPA were found to have synergistic effects in suppressing LPS-stimulated NO and endogenous NO levels. Importantly, very low doses of CUR 2.5 μM and DHA or EPA of 0.78 μM could synergistically suppress the LPS-induced prostaglandin E2 (PGE2). The combinations were also found to suppress iNOS, COX-2, 5-lipoxygenase (5-LOX) and cPLA2 but induce HO-1. Taken together, the present study clearly shows the synergistic anti-inflammatory as well as anti-oxidative stress effects of CUR and PUFA. © 2009 Elsevier Inc. All rights reserved. Source

Kim H.,Center for Cancer Prevention Research | Kim H.,Rutgers University | Ramirez C.N.,Rutgers University | Su Z.-Y.,Chung Yuan Christian University | And 2 more authors.
Journal of Nutritional Biochemistry | Year: 2016

Ursolic acid (UA), a well-known natural triterpenoid found in abundance in blueberries, cranberries and apple peels, has been reported to possess many beneficial health effects. These effects include anticancer activity in various cancers, such as skin cancer. Skin cancer is the most common cancer in the world. Nuclear factor E2-related factor 2 (Nrf2) is a master regulator of antioxidative stress response with anticarcinogenic activity against UV- and chemical-induced tumor formation in the skin. Recent studies show that epigenetic modifications of Nrf2 play an important role in cancer prevention. However, the epigenetic impact of UA on Nrf2 signaling remains poorly understood in skin cancer. In this study, we investigated the epigenetic effects of UA on mouse epidermal JB6 P+ cells. UA inhibited cellular transformation by 12-O-tetradecanoylphorbol-13-acetate at a concentration at which the cytotoxicity was no more than 25%. Under this condition, UA induced the expression of the Nrf2-mediated detoxifying/antioxidant enzymes heme oxygenase-1, NAD(P)H:quinone oxidoreductase 1 and UDP-glucuronosyltransferase 1A1. DNA methylation analysis revealed that UA demethylated the first 15 CpG sites of the Nrf2 promoter region, which correlated with the reexpression of Nrf2. Furthermore, UA reduced the expression of epigenetic modifying enzymes, including the DNA methyltransferases DNMT1 and DNMT3a and the histone deacetylases (HDACs) HDAC1, HDAC2, HDAC3 and HDAC8 (Class I) and HDAC6 and HDAC7 (Class II), and HDAC activity. Taken together, these results suggest that the epigenetic effects of the triterpenoid UA could potentially contribute to its beneficial effects, including the prevention of skin cancer. © 2015 Elsevier Inc. Source

Yang A.Y.,Center for Cancer Prevention Research | Lee J.H.,Center for Cancer Prevention Research | Lee J.H.,Korea University | Shu L.,Center for Cancer Prevention Research | And 12 more authors.
Life Sciences | Year: 2014

Aims Ultraviolet irradiation and carcinogens have been reported to induce epigenetic alterations, which potentially contribute to the development of skin cancer. We aimed to study the genome-wide DNA methylation profiles of skin cancers induced by ultraviolet B (UVB) irradiation and 7,12-dimethylbenz(a)anthracene (DMBA)/12-O-tetradecanoylphorbol-1,3-acetate (TPA). Main methods Methylated DNA immunoprecipitation (MeDIP) followed by next-generation sequencing was utilized to ascertain the DNA methylation profiles in the following common mouse skin cancer models: SKH-1 mice treated with UVB irradiation and CD-1 mice treated with DMBA/TPA. Ingenuity® Pathway Analysis (IPA) software was utilized to analyze the data and to identify gene interactions among the different pathways. Key findings 6003 genes in the UVB group and 5424 genes in the DMBA/TPA group exhibited a greater than 2-fold change in CpG methylation as mapped by the IPA software. The top canonical pathways identified by IPA after the two treatments were ranked were pathways related to cancer development, cAMP-mediated signaling, G protein-coupled receptor signaling and PTEN signaling associated with UVB treatment, whereas protein kinase A signaling and xenobiotic metabolism signaling were associated with DMBA/TPA treatment. In addition, the mapped IL-6-related inflammatory pathways displayed alterations in the methylation profiles of inflammation-related genes linked to UVB treatment. Significance Genes with altered methylation were ranked in the UVB and DMBA/TPA models, and the molecular interaction networks of those genes were identified by the IPA software. The genome-wide DNA methylation profiles of skin cancers induced by UV irradiation or by DMBA/TPA will be useful for future studies on epigenetic gene regulation in skin carcinogenesis. © 2014 Elsevier Inc. Source

Wu T.-Y.,Center for Cancer Prevention Research | Khor T.O.,Center for Cancer Prevention Research | Lee J.H.,Center for Cancer Prevention Research | Cheung K.L.,Center for Cancer Prevention Research | And 3 more authors.
Current Drug Metabolism | Year: 2013

Cancer chemopreventive activities of various phytochemicals have been attributed to the modulation of xenobiotic disposition, which includes absorption, distribution, metabolism, and excretion. The interaction between xenobiotics and xenobiotic-metabolizing enzymes (XMEs) is bidirectional. XMEs are responsible for the biotransformation of xenobiotics such as bioactivation and detoxification. Conversely, xenobiotics affect XMEs through transcriptional regulation (induction or suppression) and post-translational interactions (inhibition or activation). Similar relationships also exist between xenobiotics and their transporters. Studies conducted over the past decade have demonstrated that the transcription factor, nuclear factor erythroid 2-related factor 2 (Nrf2), plays a critical role in the regulation of detoxifying enzymes and transporters through a signaling system that senses and responds to redox imbalance. The role of Nrf2 in the interaction between chemopreventive phytochemicals and detoxifying enzymes/transporters has become an important topic in cancer chemoprevention. In this review, the genetic and epigenetic factors that contribute to Nrf2-mediated regulation of detoxifying XMEs and transporters are discussed in the context of cancer chemoprevention. Phytochemicals may modulate the genome as well as epigenome, altering the regulation of XMEs and transporters, which may be critical for both cancer chemoprevention and the prevention of other oxidative stress-and inflammatory-related diseases, including cardiovascular, metabolic and neurological pathologies. The pharmacogenomic expression of XMEs and transporters, with an emphasis on both genomics and epigenetics, will also be discussed. © 2013 Bentham Science Publishers. Source

Kong A.-N.T.,Center for Cancer Prevention Research | Kong A.-N.T.,Rutgers University | Zhang C.,Center for Cancer Prevention Research | Zhang C.,Rutgers University | And 2 more authors.
Cancer Prevention Research | Year: 2013

In cancer, genetic mutations have long been considered to be the only driver of neoplasia. However, there is increasing evidence that epigenetic alterations could also play a major role in carcinogenesis and cancer. A number of experimental and epidemiologic studies have shown that many classes of dietary phytochemicals possess cancer-preventive and epigenetic-modifying properties. The report by Derry and colleagues in this issue of the journal shows that grape seed extract (GSE) prevents azoxymethane (AOM)-induced colon colitis via epigenetic microRNA (miRNA) regulation. Although the precise mechanism underlying the control of miRNA expression is not well understood currently, epigenetic changes could play a major role. This report, along with increasing evidence showing the impact of dietary phytochemicals on epigenetic activities, offers new perspectives on miRNA and epigenetic regulation in cancer prevention. Source

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