Reactivation of RASSF1A in Breast Cancer Cells by Curcumin

Du, Liping; Xie, Zhiliang; Wu, Lai-Chu; Chiu, Ming; Lin, Jiayuh; Chan, Kenneth K.; Liu, Shujun; Liu, Zhongfa

doi:10.1080/01635581.2012.717682

Cited by 84 publications

(49 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…There are Sp1 binding sites on DNMT1 (39) and Yu et al (40) observed that curcumin inhibits DNMT1 expression, possibly by inhibiting Sp1 activity. Similar results were observed by Du et al (41). Yie et al (42) also demonstrated that overexpression of Sp1 in live cancer cells promotes the expression of DNMT1.…”

Section: Discussionsupporting

confidence: 78%

Casticin inhibits the activity of transcription factor Sp1 and the methylation of RECK in MGC803 gastric cancer cells

Yang

Huang

et al. 2016

Experimental and Therapeutic Medicine

View full text Add to dashboard Cite

Abstract. The present study investigated the effect of casticin on reversion-inducing-cysteine-rich protein with kazal motifs (RECK) gene expression and intracellular methylation levels in MGC803 gastric cancer cells. Cells were treated with 1, 10 and 30 µmol/l casticin. Western blotting and reverse transcription-quantitative polymerase chain reaction assays were performed to determine the protein expression and mRNA levels of RECK and DNA methyltransferase 1 (DNMT1), respectively. High-performance liquid chromatography coupled to electrospray ionization tandem mass spectrometry was used to detect RECK methylation. In addition, MGC803 cell proliferation was measured by an MTT assay and the DNA-binding activity of transcription factor Sp1 was determined using an enzyme-linked immunosorbent assay. The results demonstrated that treatment with 1, 10 and 30 µmol/l casticin significantly increased RECK protein expression and mRNA levels. In addition, casticin (30 µmol/l) decreased RECK promoter methylation levels by 31%, global DNA methylation levels by 39% and nuclear methylation activity by 71.6%. Furthermore, casticin downregulated the mRNA levels and protein expression of DNMT1. The MTT assay demonstrated that MGC803 cell proliferation was inhibited by casticin treatment and DNA binding assays indicated that casticin reduced the DNA-binding activity of Sp1. The present study therefore indicated that casticin inhibits the proliferation of gastric cancer MGC803 cells by upregulating RECK gene expression and reducing intracellular methylation levels.

show abstract

Section: Discussionsupporting

confidence: 78%

Casticin inhibits the activity of transcription factor Sp1 and the methylation of RECK in MGC803 gastric cancer cells

Yang

Huang

et al. 2016

Experimental and Therapeutic Medicine

View full text Add to dashboard Cite

show abstract

“…The data obtained from MSP and BGS demonstrated that 5 μM PEITC significantly reduced CpG methylation in the RASSF1A gene. Previous studies have reported that reactivation of RASSF1A expression is mediated by promoter demethylation in various types of cancers [31, 42, 43]. We hypothesized that PEITC-induced RASSF1A promoter demethylation increases RASSF1A expression in LNCaP cells.…”

Section: Resultsmentioning

confidence: 92%

“…Recent meta-analyses have revealed that RASSF1A methylation in tumor tissues was directly correlated with the Gleason Score (GS), serum prostate-specific antigen (PSA) level and tumor stage in PCa, indicating that RASSF1A promoter methylation might be a potential biomarker for prostate cancer prognosis and therapy[29, 30]. Several studies have described the effect of phytochemicals, such as curcumin and mahanine, in reversing RASSF1A promoter hypermethylation and restoring RASSF1A expression in breast cancer and prostate cancer cells[31, 32]. …”

Section: Introductionmentioning

confidence: 99%

Epigenetic reactivation of RASSF1A by phenethyl isothiocyanate (PEITC) and promotion of apoptosis in LNCaP cells

Boyanapalli

Fuentes

et al. 2016

Pharmacological Research

View full text Add to dashboard Cite

Epigenetic silencing of tumor suppressor genes is a phenomenon frequently observed in multiple cancers. Ras-association domain family 1 isoform A (RASSF1A) is a well-characterized tumor suppressor that belongs to the Ras-association domain family. Several studies have demonstrated that hypermethylation of the RASSF1A promoter is frequently observed in lung, prostate, and breast cancers. Phenethyl isothiocyanate (PEITC), a phytochemical abundant in cruciferous vegetables, possesses chemopreventive activities; however, its potential involvement in epigenetic mechanisms remains elusive. The present study aimed to examine the role of PEITC in the epigenetic reactivation of RASSF1A and the induction of apoptosis in LNCaP cells. LNCaP cells were treated for 5 days with 0.01% DMSO, 2.5 or 5 μM PETIC or 2.5 μM azadeoxycytidine (5-Aza) with 0.5 μM trichostatin A (TSA). We evaluated the effects of these treatments on CpG demethylation using methylation-specific polymerase chain reaction (MSP) and bisulfite genomic sequencing (BGS). CpG demethylation was significantly enhanced in cells treated with 5 μM PEITC and 5-Aza+TSA; therefore, the latter treatment was used as a positive control in subsequent experiments. The decrease in RASSF1A promoter methylation correlated with an increase in expression of the RASSF1A gene in a dose-dependent manner. To confirm that promoter demethylation was mediated by DNA methyltransferases (DNMTs), we analyzed the expression levels of DNMTs and histone deacetylases (HDACs) at the gene and protein levels. PEITC reduced DNMT1, 3A and 3B protein levels in a dose-dependent manner, and 5 μM PEITC significantly reduced DNMT3A and 3B protein levels. HDAC1, 2, 4 and 6 protein expression was also inhibited by 5 μM PEITC. The combination of 5-Aza and TSA, a DNMT inhibitor and a HDAC inhibitor, respectively, was used as a positive control as this treatment significantly inhibited both HDACs and DNMTs. The function of RASSF1A reactivation in promoting apoptosis and inducing G2/M cell cycle arrest was analyzed using flow-cytometry analysis with Annexin V and propidium iodide (PI). Growth inhibition effect on LNCaP cells were investigated by colony formation assay. In addition, we analyzed p21, caspase-3 and 7, Bax, and Cyclin B1 protein levels. Flow-cytometry analysis of cells stained with PI alone demonstrated that 5 μM PEITC promotes early apoptosis and G2/M cell cycle arrest. Flow cytometry analysis of cells stained with Annexin V and PI also demonstrated an increased proportion of cells in early apoptosis in cells treated with 5 μM PEITC or 5-Aza with TSA. PEITC and efficiently inhibit colony numbers and total area. In addition, 5 μM PEITC significantly enhanced p21, caspase-3, 7 and Bax levels and reduced Cyclin B1 expression compared with the control group. Collectively, the results of our study suggest that PEITC induces apoptosis in LNCaP cells potentially by reactivating RASSF1A via epigenetic mechanisms.

show abstract

“…Epigenetic modifications occur on >60 CpG sites spanning the RASSF1A promoter and exon 1. Silencing can be detected in numerous cell lines and can be reversed using 5-aza-2 0 -deoxycytidine, machanine [76], curcumin [121] or the approved FDA drug for treating acute myeloid leukemia, decitabine.…”

Section: Epigenetic Regulation Of the Rassfsmentioning

confidence: 99%

RASSF tumor suppressor gene family: Biological functions and regulation

et al. 2014

View full text Add to dashboard Cite

a b s t r a c tGenetic changes through allelic loss and nucleic acid or protein modifications are the main contributors to loss of function of tumor suppressor proteins. In particular, epigenetic silencing of genes by promoter hypermethylation is associated with increased tumor severity and poor survival. The RASSF (Ras association domain family) family of proteins consists of 10 members, many of which are tumor suppressor proteins that undergo loss of expression through promoter methylation in numerous types of cancers such as leukemia, melanoma, breast, prostate, neck, lung, brain, colorectal and kidney cancers. In addition to their tumor suppressor function, RASSF proteins act as scaffolding agents in microtubule stability, regulate mitotic cell division, modulate apoptosis, control cell migration and cell adhesion, and modulate NFjB activity and the duration of inflammation. The ubiquitous functions of these proteins highlight their importance in numerous physiological pathways. In this review, we will focus on the biological roles of the RASSF family members and their regulation.

show abstract

Reactivation of RASSF1A in Breast Cancer Cells by Curcumin

Cited by 84 publications

References 28 publications

Casticin inhibits the activity of transcription factor Sp1 and the methylation of RECK in MGC803 gastric cancer cells

Casticin inhibits the activity of transcription factor Sp1 and the methylation of RECK in MGC803 gastric cancer cells

Epigenetic reactivation of RASSF1A by phenethyl isothiocyanate (PEITC) and promotion of apoptosis in LNCaP cells

RASSF tumor suppressor gene family: Biological functions and regulation

Contact Info

Product

Resources

About