Pharmacodynamics of curcumin as DNA hypomethylation agent in restoring the expression of Nrf2 via promoter CpGs demethylation

Khor, Tin Oo; Huang, Ying; Wu, Tien-Yuan; Shu, Limin; Lee, Jong-Hun; Kong, Ah‐Ng Tony

doi:10.1016/j.bcp.2011.07.065

Cited by 215 publications

(186 citation statements)

References 53 publications

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“…Our findings showed that CUR demethylated CpG sites of NEP gene at 5 μM in these two cell lines, along with a significant upregulation of NEP level, which is as effective as 5-aza-CdR treatment. Similar effects of CUR on DNA demethylation have been shown in several genes such as Nrf2 and Neurog 1 (39,40). However, it is also reported that demethoxycurcumin and bisdemethoxycurcumin but not , and 72 h. Proteins were then assessed for levels of COX-2 and iNOS.…”

Section: Inhibition Of Akt/nf-κb Signaling By Cur Is Associated With mentioning

confidence: 75%

Curcumin Inhibits the AKT/NF-κB Signaling via CpG Demethylation of the Promoter and Restoration of NEP in the N2a Cell Line

Deng

Wang

et al. 2014

AAPS J

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Abstract. Curcumin (CUR), a non-toxic polyphenol from Curcuma longa, has been investigated as a potential therapy with anti-inflammatory and anti-oxidative effects for Alzheimer's disease (AD), which depicts features of chronic inflammatory environment resulting in cellular death. However, it remains largely unknown whether the anti-inflammatory effect of CUR in AD is associated with its property of CpG demethylation, which is another function of CUR with the most research interest during recent years. Neprilysin (NEP, EP24.11), a zinc-dependent metallopeptidase expressed relatively low in the brain, is emerging as a potent inhibitor of AKT/Protein Kinase B. In addition, hypermethylated promoter of NEP has been reported to be associated with decreases in NEP expression. In the present study, using bisulfite-sequencing PCR (BSP) assay, we showed that the CpG sites in NEP gene were hypermethylated both in wild-type mouse neuroblastoma N2a cells (N2a/wt) and N2a cells stably expressing human Swedish mutant amyloid precursor protein (APP) (N2a/APPswe) associated with familial early onset AD. CUR treatment induced restoration of NEP gene via CpG demethylation. This CUR-mediated upregulation of NEP expression was also concomitant with the inhibition of AKT, subsequent suppression of nuclear transcription factor-κB (NF-κB) and its downstream pro-inflammatory targets including COX-2, iNOS in N2a/APPswe cells. This study represents the first evidence on a link between CpG demethylation effect on NEP and anti-inflammation ability of CUR that may provide a novel mechanistic insight into the anti-inflammatory actions of CUR as well as new basis for using CUR as a therapeutic intervention for AD.

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Section: Inhibition Of Akt/nf-κb Signaling By Cur Is Associated With mentioning

confidence: 75%

Curcumin Inhibits the AKT/NF-κB Signaling via CpG Demethylation of the Promoter and Restoration of NEP in the N2a Cell Line

Deng

Wang

et al. 2014

AAPS J

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“…TRAMP-C1 cells (provided by Dr. Barbara Foster, Department of Pharmacology and Therapeutics, Roswell Park Cancer Institute, Buffalo, NY), originally derived from TRAMP prostate tumor (21), were maintained in a humidified incubator with 5% CO 2 at 37°C, cultured in Dulbecco's modified Eagle's medium (DMEM; Invitrogen Corp., Carlsbad, CA) supplemented with 10% (v/v) fetal bovine serum (FBS; Invitrogen Corp., Grand Island, NY), penicillin 100 U/ ml, and streptomycin 100 μg/ml (Invitrogen Corp., Grand Island, NY). Cells were seeded in 10-cm plates for 24 h and then treated with different concentrations of DIM or 0.1% DMSO (control) in DMEM containing 1% FBS for 5 days and changed every 2 days (14).…”

Section: Reagents and Cell Culturementioning

confidence: 99%

“…The genomic DNAs were extracted and subjected to bisulfite conversion carried out using 750 ng of genomic DNA and applying to EZ DNA Methylation Gold Kits (Zymo Research Corp., Orange, CA) following the manufacturer's instructions. The converted DNA was amplified by PCR-utilizing Platinum PCR SuperMix (Invitrogen, Grand Island, NY) with a set of specific primers, forward: 5′-AGT TAT GAA GTA GTA GTA AAA A-3′ and reverse: 5′-AAT ATA ATC TCA TAA AAC CCC AC-3′, amplifying the first five CpGs located between −1,266 and −1,086 of the promoter region of Nrf2 with the translation initiation site defined as +1 (11,14). Gel extraction using Qiaquick™ gel extraction kit (Qiagen, Valencia, CA) were used to purify the PCR products, then cloned into pCR4 TOPO vector using a TOPO™ TA Cloning kit (Invitrogen, Grand Island, NY).…”

Section: Dna Extraction and Bisulfite Genomic Sequencingmentioning

confidence: 99%

“…Gel extraction using Qiaquick™ gel extraction kit (Qiagen, Valencia, CA) were used to purify the PCR products, then cloned into pCR4 TOPO vector using a TOPO™ TA Cloning kit (Invitrogen, Grand Island, NY). Plasmids DNA from at least 20 colonies of each treatment were prepared using QIAprep Spin Miniprep Kit (Qiagen, Valencia, CA) and sequenced (Genwiz, Piscataway, NJ) as we have previously reported (11,14).…”

Section: Dna Extraction and Bisulfite Genomic Sequencingmentioning

confidence: 99%

“…Polyphenols and isothiocyanates from green tea and cruciferous vegetables as nontoxic dietary phytochemicals have been reported to suppress initiation and development of cancer by epigenetic modifications both in vivo and in vitro (13). Recently, our laboratory showed that curcumin, a potent anticancer agent against many cancers such as prostate cancer, suppresses DNA methyltransferases (DNMT) expression and modifies the histone deacetylases (HDAC) activity in human prostate LNCaP cells, which might contribute to DNA demethylation in promoter region of Nrf2 gene in TRAMP-C1 cells as well as Neurog1 gene in LNCaP cells (14,15). 3,3′-diindolylmethane (DIM), a compound derived from indole-3-carbinol (I3C), is found abundantly in cruciferous vegetables and its multi-target anticancer and cancer chemopreventive effects have been demonstrated in many in vivo and in vitro cancer models (16)(17)(18)(19).…”

Section: Introductionmentioning

confidence: 99%

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Epigenetic Modifications of Nrf2 by 3,3′-diindolylmethane In Vitro in TRAMP C1 Cell Line and In Vivo TRAMP Prostate Tumors

Khor

et al. 2013

AAPS J

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Abstract. 3,3′-diindolylmethane (DIM) is currently being investigated in many clinical trials including prostate, breast, and cervical cancers and has been shown to possess anticancer effects in several in vivo and in vitro models. Previously, DIM has been reported to possess cancer chemopreventive effects in prostate carcinogenesis in TRAMP mice; however, the in vivo mechanism is unclear. The present study aims to investigate the in vitro and in vivo epigenetics modulation of DIM in TRAMP-C1 cells and in TRAMP mouse model. In vitro study utilizing TRAMP-C1 cells showed that DIM suppressed DNMT expression and reversed CpG methylation status of Nrf2 resulting in enhanced expression of Nrf2 and Nrf2-target gene NQO1. In vivo study, TRAMP mice fed with DIM-supplemented diet showed much lower incidence of tumorigenesis and metastasis than the untreated control group similar to what was reported previously. DIM increased apoptosis, decreased cell proliferation and enhanced Nrf2 and Nrf2-target gene NQO1 expression in prostate tissues. Importantly, immunohistochemical analysis showed that DIM reduced the global CpG 5-methylcytosine methylation. Focusing on one of the early cancer chemopreventive target gene Nrf2, bisulfite genomic sequencing showed that DIM decreased the methylation status of the first five CpGs of the Nrf2 promoter region, corroborating with the results of in vitro TRAMP-C1 cells. In summary, our current study shows that DIM is a potent cancer chemopreventive agent for prostate cancer and epigenetic modifications of the CpG including Nrf2 could be a potential mechanism by which DIM exerts its chemopreventive effects.

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Epigenetics, Plant (Poly)phenolics, and Cancer Prevention

Gerhäuser¹

2014

Recent Advances in Polyphenol Research

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Pharmacodynamics of curcumin as DNA hypomethylation agent in restoring the expression of Nrf2 via promoter CpGs demethylation

Cited by 215 publications

References 53 publications

Curcumin Inhibits the AKT/NF-κB Signaling via CpG Demethylation of the Promoter and Restoration of NEP in the N2a Cell Line

Curcumin Inhibits the AKT/NF-κB Signaling via CpG Demethylation of the Promoter and Restoration of NEP in the N2a Cell Line

Epigenetic Modifications of Nrf2 by 3,3′-diindolylmethane In Vitro in TRAMP C1 Cell Line and In Vivo TRAMP Prostate Tumors

Epigenetics, Plant (Poly)phenolics, and Cancer Prevention

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