This study investigated the inhibitory effects of curcumin on proliferation of hematological malignant cells in vitro and the anti-tumor mechanism at histone acetylation/histone deacetylation levels. The effects of curcumin and histone deacetylase inhibitor trichostatin A (TSA) on the growth of Raji cells were tested by MTT assay. The expression of acetylated histone-3 (H(3)) in Raji, HL60 and K562 cells, and peripheral blood mononuclear cells (PBMCs) treated with curcumin or TSA was detected by immunohistochemistry and FACS. The results showed curcumin inhibited proliferation of Raji cells significantly in a time- and dose-dependent fashion, while exhibited low toxicity in PBMCs. Curcumin induced up-regulation of the expression of acetylated H(3) dose-dependently in all malignant cell lines tested. In conclusion, curcumin inhibited proliferation of Raji cells selectively, enhanced the level of acetylated (H(3)) in Raji, HL60, and K562 cells, which acted as a histone deacetylase inhibitor like TSA. Furthermore, up-regulation of H(3) acetylation may play an important role in regulating the proliferation of Raji cells.
Acetylation/drug effects ; Antineoplastic Agents/*pharmacology ; Cell Proliferation/*drug effects ; Curcumin/*pharmacology ; HL-60 Cells ; Histone Deacetylase Inhibitors/pharmacology ; Histones/chemistry ; Histones/*drug effects ; K562 Cells ; Triclosan/pharmacology

This study was purposed to investigate the effects of phenylhexyl isothiocyanate (PHI) on Burkitt lymphoma Daudi cell line and regulation of histone acetylation and methylation in Daudi cells, and to explore the potential mechanism. The apoptotic rate of Daudi cells treated with PHI was measured by flow cytometry, the changes of histone H3 and H4 acetylation, histone H3K9 and H3K4 methylation in Daudi cells treated with PHI were detected by Western blot. The results showed that PHI could induce apoptosis of Daudi cells, increased the acetylation level of H3 and H4, enhanced the methylation of H3K4, but reduced the methylation of H3K9. It is concluded that the PHI can up-regulate the acetylation level of histone H3 associated with transcription stimulation and the methylation of histone H3K4, down-regulate the methylation on histone H3K9 associated with transcription inhibition, promotes the apoptosis of Daudi cells. PHI may be a potential agent for target therapy of lymphoma.
Acetylation ; Apoptosis ; drug effects ; Burkitt Lymphoma ; genetics ; metabolism ; Cell Line, Tumor ; Histones ; genetics ; metabolism ; Humans ; Isothiocyanates ; pharmacology ; Methylation

OBJECTIVETo establish a rapid, relatively quantitative method of detecting acetylated proteins.

METHODSThe proteins of Jurkat cells were acetylated by Trichostatin A (TSA) at different concentrations, then enriched and purified by anti-acetylated lysine antibodies affinity chromatography colum. The components eluted by acid were fixed on the microplate, the levels of acetylated proteins were tested by ELISA, and their components were identified by MALDI-TOF-TOF mass spectrometry. Also the above-mentioned methods were applied to the other three agents (gallic acid, emodin and monoacetylated emodin A).

RESULTSThat 4 × 10(5) Jurkat cells treated with 1 µmol/L TSA produced the optimal acetylated effect, up to 22 acetylated proteins were identified by MALDI-TOF-TOF, of them 15 were acetylated histones. The other three agents also induced acetylation, the relative values of acetylated proteins of Jurkat cells treated with 35.09 µmol/L and 17.54 µmol/L gallic acid were 4.3% and 14.2% respectively; those as of 28.7% and 11.5% treated with 1.47 µmol/L and 2.94 µmol/L emodin; those as of 22.0% and 3.6% treated with 152.91 µmol/L and 30.58 µmol/L monoacetylated emodin A.

CONCLUSIONThe method based on affinity chromatography colum may be useful for the detection of acetylated proteins, and could be used to screen agents which target to histone deacetylase.

Acetylation ; Chromatography, Affinity ; Histones ; analysis ; Humans ; Hydroxamic Acids ; pharmacology ; Jurkat Cells ; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization

There are large knowledge gaps regarding how to control stem cells growth and differentiation. The limitations of currently available technologies, such as growth factors and/or gene therapies has led to the search of alternatives. We explore here how a cell's epigenome influences determination of cell type, and potential applications in tissue engineering. A prevalent epigenetic modification is the acetylation of DNA core histone proteins. Acetylation levels heavily influence gene transcription. Histone deacetylase (HDAC) enzymes can remove these acetyl groups, leading to the formation of a condensed and more transcriptionally silenced chromatin. Histone deacetylase inhibitors (HDACis) can inhibit these enzymes, resulting in the increased acetylation of histones, thereby affecting gene expression. There is strong evidence to suggest that HDACis can be utilised in stem cell therapies and tissue engineering, potentially providing novel tools to control stem cell fate. This review introduces the structure/function of HDAC enzymes and their links to different tissue types (specifically bone, cardiac, neural tissues), including the history, current status and future perspectives of using HDACis for stem cell research and tissue engineering, with particular attention paid to how different HDAC isoforms may be integral to this field.
Acetylation ; drug effects ; Histone Deacetylase Inhibitors ; pharmacology ; Histone Deacetylases ; metabolism ; Histones ; isolation & purification ; metabolism ; Humans ; Tissue Engineering

OBJECTIVETo investigate the effects of PHI on histone acetylation and methylation in hepatocellular carcinoma line SMMC-7721 cells.

METHODSApoptosis was measured by TUNNEL assay. Histone methylation and acetylation were detected by Western blot.

RESULTSPHI inhibited cells growth and induced apoptosis. PHI treatment resulted in increased acetylation of histone H3 and H4 , elevated level of histone H3 lysine 4 methylation, and decreased level of histone H3 lysine 9 methylation.

CONCLUSIONSPHI can modulate both histone acetylation and methylation, which could remodel chromatin structure. PHI may be a novel anticancer drug.

Acetylation ; Apoptosis ; drug effects ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Histones ; metabolism ; Humans ; Isothiocyanates ; pharmacology ; Methylation

OBJECTIVETo investigate the effect of trichostatin A(TSA) on SGC- 7901 cells.

METHODSCytotoxicity and cell viability of gastric cancer cell line SGC- 7901 were assayed by MTT method. Morphologic assessment of apoptosis was performed with fluorescence microscope. Cell cycle and apoptosis rate were analyzed by flow cytometry. Histone H3 acetylation was detected by Western blot.

RESULTSTSA showed apparently cytotoxicity in SGC- 7901 cells. The growth curve showed the growth ratio decreased with the increase of TSA concentration. Apoptosis rate were significantly different between TSA treated group(75 ng/ml for 72 h)and control group (P < 0.05). Morphologic changes of apoptosis including nuclear chromatin condensation and fluorescence strength were observed with fluorescence microscope.TSA treatment (75 ng/ml for 72 h) sensitively induced apoptosis in the cell,which was demonstrated by the migration of many cells to the sub- G1 phase,the reduction of G1- phase cells and the increment of apoptosis rate (29.54%) in flow cytometric analysis. The expression of acetylated histone H3 was increased in TSA group(75 ng/ml) for 48 h compared with control group by Western blot.

CONCLUSIONSTSA can induce SGC- 7901 cell apoptosis. The expression of acetylated histone H3 may contribute to the apoptosis.

Acetylation ; drug effects ; Apoptosis ; drug effects ; Cell Line, Tumor ; Histones ; metabolism ; Humans ; Hydroxamic Acids ; pharmacology ; Stomach Neoplasms

In order to determine whether H1 histone proteins are associated with innate immune antimicrobial response in goldfish, we extracted the total RNA from the hemocytes of goldfish (Carassius auratus), designed 3 pairs of primers based on the previous antimicrobial peptide sequences from fish and performed RT-PCR. Among 3 obtained-PCR products, we identified a novel histone H1 coding sequence of 576 bp which belongs to the histone H1 family and is 78% homologous with the amino acid sequence of histone H1 from Salmon salar that had been found with an important role in salmon defenses against infectious pathogens. The H1 histone of goldfish contained 3 predicting cleavage sites that divided the protein into 4 parts. We successfully cloned and expressed the whole CDs (No ATG) of H1 histone and its N-terminal part (2-38aa) in Pichia pPIC9K expression system. The products of H1 histone and its N-terminal deriving peptide (AEVAPAASAPPAKAPKKKSAAKAKKAGPAVGDLIVKA) show antimicrobial activity. The results suggested that the H1 histone fragment reported in this paper is a novel antimicrobial peptide found in goldfish. H1 histone plays an important role in innate immune responses of goldfish.
Amino Acid Sequence ; Animals ; Anti-Bacterial Agents ; biosynthesis ; pharmacology ; Cloning, Molecular ; Goldfish ; genetics ; metabolism ; Histones ; biosynthesis ; genetics ; pharmacology ; Molecular Sequence Data ; Peptide Fragments ; biosynthesis ; genetics

OBJECTIVETo investigate the effects of curcumin on the acetylation of histone H3, P53 and the proliferation of NB4 cells.

METHODSThe total protein was extracted from NB4 cells treated without or with different concentrations of curcumin ( 50, 25, 12.5, 6.25 and 3.125 micromol/L) for different time (0, 4, 8, 12, 24 h). Western blot analysis was performed to determine the levels of acetylated histone H3, P53 and acetylated P53. MTT assay was performed to examine the growth inhibition effect of curcumin on NB4 cells.

RESULTSCurcumin could inhibit the proliferation of NB4 cells in a time- and dose- dependent manner, with the IC50 at 24 h and 36 h of 40 micromol/L and 25 micromol/L, respectively. The levels of histone H3 acetylation, P53 expression and P53 acetylation were increased obviously.

CONCLUSIONCurcumin functions as a deacetylase inhibitor,which could increase the level of acetylated histone H3, enhance the expression and activity of tumor suppressor P53, and inhibit the proliferation of NB4 cells.

Acetylation ; drug effects ; Antineoplastic Agents ; pharmacology ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Curcumin ; pharmacology ; Histones ; metabolism ; Humans ; Tumor Suppressor Protein p53 ; metabolism

This study was aimed to investigate the methylation status of WT1 gene in leukemia cell lines and its relation with expression of WT1 gene. The WT1 gene was silenced by DNA methylation or histone deacetylation, and the expression of WT1 gene was induced by using HDAC inhibitor and/or demethylation agent of DNA. Some leukemia cell lines (U937, HL-60, K562, KG1) were detected by RT-PCR, MS-PCR, restriction analysis, and DNA sequencing. U937 leukemic cells without WT1 mRNA expression were incubated with HDAC inhibitor Trichostatin A (TSA) and/or demethylation agent decitabine. The results showed that the U937 cells did not express WT1 gene, but HL-60, K562 and KG1 cells highly expressed WT1 gene; WT1 gene was unmethylated in HL-60 cells, but methylated in K562 and U937 cells. WT1 expression could be reactivated by co-incubation with TSA and decitabine, but not was observed by using single drug. It is concluded that WT1 promoter is methylated in some leukemia cells, however, the methylation can not affect its expression. DNA methylation and deacetylation of histones are synergistic to inhibit the expression of WT1 in leukemic U937 cells, the combination of TSA with decitabine can induce expression of WT1 gene.
Azacitidine ; analogs & derivatives ; pharmacology ; DNA Methylation ; Gene Silencing ; HL-60 Cells ; Histones ; metabolism ; Humans ; Hydroxamic Acids ; pharmacology ; K562 Cells ; Promoter Regions, Genetic ; U937 Cells ; WT1 Proteins ; genetics

Histone deacetylase (HDAC) has been highlighted as one of key players in tumorigenesis and angiogenesis. Recently, several derivatives of psammaplin (Psams) from a marine sponge have been known to inhibit the HDAC activity, but the molecular mechanism for the inhibition has not fully understood. Here, we explored the mode of action of Psams for the inhibition of HDAC activity in the molecular and cellular level. Among the derivatives, psammaplin A (Psam A) showed the potent inhibitory activity in enzyme assay and anti-proliferation assay with IC50 value of 0.003 and 1 microM, respectively. Psam A selectively induced hyperacetylation of histones in the cells, resulting in the upregulation of gelsolin, a well-known HDAC target gene, in a transcriptional level. In addition, reduced Psam A showed a stronger inhibitory activity than that of non-reduced one. Notably, glutathione-depleted cells were not sensitive to Psam A, implying that cellular reduction of the compound is responsible for the HDAC inhibition of Psam A after uptake into the cells. Together, these data demonstrate that Psam A could exhibit its activity under the reduced condition in the cells and be a new natural prodrug targeting HDAC.
Tyrosine/*analogs & derivatives/chemistry/pharmacology ; Prodrugs/chemistry/*pharmacology ; Oxidation-Reduction ; Molecular Structure ; Humans ; Histones/metabolism ; Histone Deacetylases/*antagonists & inhibitors/*classification/genetics/metabolism ; Hela Cells ; Enzyme Inhibitors/chemistry/*pharmacology ; Disulfides/chemistry/*pharmacology ; Cell Proliferation ; Biological Products/chemistry/*pharmacology ; Acetylation