BACKGROUNDPlacental multidrug resistance-associated protein 2 (MRP2), encoded by ABCC2 gene in human, plays a significant role in regulating drugs' transplacental transfer rates. Studies on placental MRP2 regulation could provide more therapeutic targets for individualized and safe pharmacotherapy during pregnancy. Currently, the roles of epigenetic mechanisms in regulating placental drug transporters are still unclear. This study aimed to investigate the effect of histone deacetylases (HDACs) inhibition on MRP2 expression in the placental trophoblast cell line and to explore whether HDAC1/2/3 are preliminarily involved in this process.

METHODSThe human choriocarcinoma-derived trophoblast cell line (Bewo cells) was treated with the HDAC inhibitors-trichostatin A (TSA) at different concentration gradients of 0.5, 1.0, 3.0, and 5.0 μmol/L. Cells were harvested after 24 and 48 h treatment. Small interfering RNA (siRNA) specific for HDAC1/HDAC2/HDAC3 or control siRNA was transfected into cells. Total HDAC activity was detected by colorimetric assay kits. HDAC1/2/3/ABCC2 messenger RNA (mRNA) and protein expressions were determined by real-time quantitative polymerase chain reaction and Western-blot analysis, respectively. Immunofluorescence for MRP2 protein expression was visualized and assessed using an immunofluorescence microscopy and ImageJ software, respectively.

RESULTSTSA could inhibit total HDAC activity and HDAC1/2/3 expression in company with increase of MRP2 expression in Bewo cells. Reduction of HDAC1 protein level was noted after 24 h of TSA incubation at 1.0, 3.0, and 5.0 μmol/L (vs. vehicle group, all P < 0.001), accompanied with dose-dependent induction of MRP2 expression (P = 0.045 for 1.0 μmol/L, P = 0.001 for 3.0 μmol/L, and P < 0.001 for 5.0 μmol/L), whereas no significant differences in MRP2 expression were noted after HDAC2/3 silencing. Fluorescent micrograph images of MRP2 protein were expressed on the cell membrane. The fluorescent intensities of MRP2 in the control, HDAC2, and HDAC3 siRNA-transfected cells were week, and no significant differences were noticed among these three groups (all P > 0.05). However, MRP2 expression was remarkably elevated in HDAC1 siRNA-transfected cells, which displayed an almost 3.19-fold changes in comparison with the control siRNA-transfected cells (P < 0.001).

CONCLUSIONSHDACs inhibition could up-regulate placental MRP2 expression in vitro, and HDAC1 was probably to be involved in this process.

Cell Line ; Histone Deacetylase 1 ; metabolism ; Histone Deacetylase 2 ; metabolism ; Histone Deacetylase Inhibitors ; pharmacology ; Histone Deacetylases ; metabolism ; Humans ; Hydroxamic Acids ; pharmacology ; Microscopy, Fluorescence ; Multidrug Resistance-Associated Proteins ; genetics ; metabolism ; RNA, Messenger ; Trophoblasts ; cytology ; metabolism

By using a cell-based high throughput screening model for the CLA-1 up-regulator, Streptomyces 203909 was found to produce up-regulator of CLA-1. A novel trichostatin analogue was isolated from the rice fermentation of Streptomyces sp. CPCC 203909by a combination of various chromatographic techniques including column chromatography (CC) over silica gel, flash C18 CC, and reversed-phase HPLC. Its structure was identified as (-)-(R,2E,4Z)-7-[(4'-dimethylamino) phenyl]-4,6-dimethyl-7-oxohepta-2,4-dienoyl-L-glutamine (1) by the spectroscopic and chemical methods, and combination with the CD spectroscopy and Marfey's method. In the prelimi- nary assays, Compound 1 showed cytotoxicity against human embryonic kidney 293 cell line with IC50 value 35.3 [µmol · L(-1).
Cell Survival ; drug effects ; Fermentation ; Hep G2 Cells ; Humans ; Hydroxamic Acids ; chemistry ; isolation & purification ; metabolism ; pharmacology ; Molecular Structure ; Streptomyces ; chemistry ; metabolism

Poly (ADP-ribose) polymerase-1 (PARP-1) inhibitors and histone deacetylase (HDAC) inhibitors have recently emerged as promising anticancer drugs. The aim of this study was to investigate the effect of combination treatment with the PARP inhibitor PJ34 and HDAC inhibitor SAHA on the proliferation of liver cancer cells. Cell proliferation and apoptosis were assessed in three human liver cancer cell lines (HepG2, Hep3B and HCC-LM3) treated with PJ34 (8 μmol/L) and SAHA (1 μmol/L), alone or combined, by Cell Counting Kit-8 assay and flow cytometry, respectively. The nude mice bearing subcutaneous HepG2 tumors were administered different groups of drugs (10 mg/kg PJ34, 25 mg/kg SAHA, 10 mg/kg PJ34+25 mg/kg SAHA), and the inhibition rates of tumor growth were compared between groups. The results showed that combined use of PJ34 and SAHA could synergistically inhibit the proliferation of liver cancer cell lines HepG2, Hep3B and HCC-LM3. The apoptosis rate of HepG2 cells treated with PJ34+SAHA was significantly higher than that of HepG2 cells treated with PJ34 or SAHA alone (P<0.05). In vivo, the tumor inhibition rates were 53.5%, 61.4% and 82.6% in PJ34, SAHA and PJ34+SAHA groups, respectively. The combined use of PJ34 and SAHA could significantly inhibit the xenograft tumor growth when compared with use of PJ34 or SAHA alone (P<0.05). It was led to conclude that PJ34 and SAHA can synergistically suppress the proliferation of liver cancer cells.
Animals ; Antineoplastic Combined Chemotherapy Protocols ; administration & dosage ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Drug Synergism ; Hep G2 Cells ; Histone Deacetylase Inhibitors ; administration & dosage ; pharmacology ; Humans ; Hydroxamic Acids ; administration & dosage ; pharmacology ; Liver Neoplasms ; drug therapy ; Mice ; Phenanthrenes ; administration & dosage ; pharmacology ; Poly(ADP-ribose) Polymerase Inhibitors ; administration & dosage ; pharmacology ; Xenograft Model Antitumor Assays

OBJECTIVETo evaluate the anti-tumor effect of the combination of suberoylanilide hydroxamic acid(SAHA) with statins(lovastatin or simvastatin) on non-small cell lung carcinoma(NSCLC) cells.

METHODSHuman NSCLC A549 cells were treated with SAHA in combination of lovastatin or simvastatin. The cell growth was analyzed by SRB method, and the apoptosis of A549 cells was assessed by flow cytometer. The expression of cleaved poly-ADP-ribose polymerase(cleaved-PARP) and p21 protein was analyzed by Western-blotting when A549 cells were challenged with 2.5μmol/L SAHA and 5μmol/L lovastatin.

RESULTSLovastatin and simvastatin synergized SAHA in the inhibition of A549 cells. SAHA induced apoptosis was also enhanced by lovastatin. Treatment with 2.5μmol/L SAHA significantly up-regulated the expression of p21 protein in 48 h, while the protein expression was reduced in combined treatment with 5μmol/L lovastatin.

CONCLUSIONStatins can synergize the anti-tumor effect of SAHA in human NSCLC cells through a p21-dependent way.

Antineoplastic Agents ; pharmacology ; Apoptosis ; Carcinoma, Non-Small-Cell Lung ; pathology ; Cell Line, Tumor ; drug effects ; Cell Proliferation ; Cyclin-Dependent Kinase Inhibitor p21 ; metabolism ; Humans ; Hydroxamic Acids ; pharmacology ; Hydroxymethylglutaryl-CoA Reductase Inhibitors ; pharmacology ; Poly(ADP-ribose) Polymerases ; metabolism

OBJECTIVETo observe the protective effects of histone deacetylase inhibitor on stress-induced myocardial injury.

METHODSHealthy male Wistar rats were randomly divided into 3 groups( n = 6), and the stress-induced myocardial injury model was established with chronic restraint stress method. The protective effects of histone deacetylase inhibitor on stress-induced myocardial injury were observed with Trichostatin A (TSA) intervention. Histone acetylation levels in myocardium of rats were detected by Western blot method, spectrophotometry method was used to dynamically determine the activity of rat serum lactate dehydrogenase (LDH), serum creatine kinase isoenzyme-MB (CK-MB) and Caspase 3, and nagar Olsen staining were used to observe the early myocardial damage.

RESULTSRestraint stress could significantly reduce the level of histone acetylation of myocardium in rats, and TSA intervention could inhibit the stress-induced reduction of myocardial levels of histone acetylation. Restraint stress could cause the significant increase of serum LDH activity ( P < 0.05), serum CK-MB activity ( P < 0.05), and the Caspase 3 activity of myocardial tissue (P < 0.05), and early myocardial damage also occurred during restraint stress. ISA intervention could significantly reduce the serum LDH activity (P < 0.05), the serum CK-MB activity (P < 0.05), the activity of myocardial tissue caspase 3 induced by restraint stress (P < 0.05), and the stress-induced myocardial injury was also attenuated by TSA intervention.

CONCLUSIONThe histone deacetylase inhibitor TSA can protect stress-induced myocardial injury.

Acetylation ; Animals ; Cardiotonic Agents ; pharmacology ; Caspase 3 ; blood ; Creatine Kinase, MB Form ; blood ; Histone Deacetylase Inhibitors ; pharmacology ; Hydroxamic Acids ; pharmacology ; L-Lactate Dehydrogenase ; blood ; Male ; Myocardium ; pathology ; Rats ; Rats, Wistar ; Restraint, Physical ; Stress, Physiological

Vorinostat (VOR) has been reported to enhance the cytotoxic effects of doxorubicin (DOX) with fewer side effects because of the lower DOX dosage in breast cancer cells. In this study, we investigated the novel mechanism underlying the synergistic cytotoxic effects of VOR and DOX co-treatment in cervical cancer cells HeLa, CaSki and SiHa cells. Co-treatment with VOR and DOX at marginal doses led to the induction of apoptosis through caspase-3 activation, poly (ADP-ribose) polymerase cleavage and DNA micronuclei. Notably, the synergistic growth inhibition induced by the co-treatment was attributed to the upregulation of the pro-apoptotic protein Bad, as the silencing of Bad expression using small interfering RNA (siRNA) abolished the phenomenon. As siRNA against p53 did not result in an increase in acetylated p53 and the consequent upregulation of Bad, the observed Bad upregulation was mediated by acetylated p53. Moreover, a chromatin immunoprecipitation analysis showed that the co-treatment of HeLa cells with VOR and DOX increased the recruitment of acetylated p53 to the bad promoter, with consequent bad transactivation. Conversely, C33A cervical cancer cells containing mutant p53 co-treated with VOR and DOX did not exhibit Bad upregulation, acetylated p53 induction or consequent synergistic growth inhibition. Together, the synergistic growth inhibition of cervical cancer cell lines induced by co-treatment with VOR and DOX can be attributed to the upregulation of Bad, which is induced by acetylated p53. These results show for the first time that the acetylation of p53, rather than histones, is a mechanism for the synergistic growth inhibition induced by VOR and DOX co-treatments.
Acetylation ; Antineoplastic Agents/*pharmacology ; Apoptosis/drug effects ; Cell Survival/drug effects ; Chromatin/metabolism ; Doxorubicin/*pharmacology ; Drug Synergism ; Female ; HeLa Cells ; Humans ; Hydroxamic Acids/*pharmacology ; Transcriptional Activation ; Tumor Suppressor Protein p53/genetics/*metabolism ; Uterine Cervical Neoplasms/metabolism ; bcl-Associated Death Protein/genetics/*metabolism

This study was aimed to investigate the effects of the DNA methylation inhibitor 5-aza-2'-deoxycytidine (5-Aza-CdR) and histone deacetylase inhibitor trichostatin A (TSA) on DLC-1 gene transcription regulation and molecular biological behaviours in the human multiple myeloma RPMI-8226 cells. The cells were treated respectively with 5-Aza-CdR and TSA alone, or the both combination; the cell proliferation and apoptosis, DLC-1 expression, the protein expression of Ras homolog family member A (RhoA) and Ras-related C3 botulinum toxin substrate 1 (Rac1) were examined by CCK-8 method, RT-PCR and ELISA, respectively. The results showed that the 5-Aza-CdR and TSA had cell growth inhibitory and apoptosis-inducing effects in dose-dependent manner (P < 0.05). Compared with a single drug (5-Aza-CdR or TSA alone), the effects were significantly enhanced after treatment with the combination of 5-Aza-CdR and TSA (P < 0.05). DLC-1 was weakly expressed in the control group; the treatment with 5-Aza-CdR alone enhanced its re-expression dose-dependently (P < 0.05). Compared with 5-Aza-CdR alone, 5-Aza-CdR plus TSA enhanced DLC-1 re-expression significantly.Compared with the control, 5-Aza-CdR and TSA significantly decreased RhoA and Rac1 protein expression (P < 0.05). It is concluded that 5-Aza-CdR and TSA can effectively reverse DLC-1 expression of RPMI-8226 cells; TSA has a synergistic effect on its re-expression. 5-Aza-CdR and TSA have significant cell growth inhibitory and apoptosis-inducing effects on RPMI-8226 cells. These effects may be related to the inhibition of Rho/Rho kinase signalling pathway.
Antimetabolites, Antineoplastic ; pharmacology ; Apoptosis ; drug effects ; Azacitidine ; administration & dosage ; analogs & derivatives ; pharmacology ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; GTPase-Activating Proteins ; metabolism ; Gene Expression ; drug effects ; Humans ; Hydroxamic Acids ; administration & dosage ; pharmacology ; Multiple Myeloma ; genetics ; pathology ; Tumor Suppressor Proteins ; metabolism

OBJECTIVETo investigate the inhibitory effect of trichostatin A (TSA) on the proliferation of HepG2 cells and explore the underlying mechanism.

METHODSHepG2 cells exposed to different concentrations of TSA for 24, 48, or 72 h were examined for cell growth inhibition using a cell counting kit, changes in cell cycle distribution with flow cytometry, cell apoptosis with annexin V-FTIC/PI double staining, and cell morphology changes under inverted microscope. The expressions of beta-catenin, HDAC1, HDAC3, H3K9, cyclinD1 and Bax proteins in the exposed cells were detected by Western blotting, and the expressions of HDAC1 and HDAC3 mRNAs by quantitative fluorescent PCR.

RESULTSExposure to TSA caused significant dose- and time-dependent inhibition of HepG2 cell proliferation (P<0.05) and resulted in increased cell percentage in G0/G1 and G2/M phases and decreased cell percentage in S phase. The apoptotic index in the control group was (6.22 ± 0.25)%, which increased to (7.17 ± 0.20)% and (18.14 ± 0.42)% after exposure to 250 and 500 nmol/L TSA, respectively. Exposure to 250 and 500 nmol/L TSA also caused cell morphology changes with numerous floating cells. The expressions of beta-catenin, H3K9 and Bax proteins were significantly increased and CyclinD1, HDAC1, and HDAC3 protein expressions decreased in TSA-treated cells, but the expressions of HDAC1 and HDAC3 mRNAs showed no significant changes.

CONCLUSIONSTSA can inhibit the proliferation of HepG2 cells and induce cell cycle arrest and apoptosis by inhibiting HDAC activity, promoting histone acetylation, and activating Wnt/beta-catenin signaling pathway.

Acetylation ; Apoptosis ; Cell Cycle Checkpoints ; Cell Proliferation ; drug effects ; Cyclin D1 ; metabolism ; Hep G2 Cells ; drug effects ; Histone Deacetylase 1 ; metabolism ; Histone Deacetylases ; metabolism ; Histones ; metabolism ; Humans ; Hydroxamic Acids ; pharmacology ; Wnt Signaling Pathway ; bcl-2-Associated X Protein ; metabolism ; beta Catenin ; metabolism

Ribosomal protein S27a (RPS27a) can perform extra-ribosomal functions besides imparting a role in ribosome biogenesis and post-translational modifications of proteins. The RPS27a gene has been reported to be over-expressed in breast fibroadenomas, colorectal and renal cancers, advanced-phase chronic myeloid leukemia (CML) and acute leukemia (AL) patients. This study was purposed to explore the function of RPS27a in CML-erythroleukemia cell line K562 cells. RPS27a was silenced by short hairpin RNA (shRNA) in K562 cells. Furthermore, the proliferation changes of K562 cells was detected by MTT method after silencing the RPS27a with suberoylanilide hydroxamic acid (SAHA), then the IC50 of K562-sh1/sh2 and K562-scr cells to SAHA was measured. The results indicated that compared with K562-scr cells, the IC50 of K562-sh1/sh2 to SAHA at 24 h and 48 h decreased (P < 0.01); RPS27a silence significantly increased the percentage of apoptotic K562-sh1/sh2 cells after incubation with 1 µmol/L, 2 µmol/L and 5 µmol/L SAHA for 24 h and 48 h as compared with that of K562-scr cells (P < 0.01). K562-sh1, K562-sh2 and K562-scr cells after incubation with or without 2 µmol/L SAHA for 48 h presented apoptosis features: i. e. chromatin condensation, nucleic fragmentation and apoptotic body formation. It is concluded that RPS27a can inhibit the apoptosis of K562 cells and RPS27a silence can potentiate sensitivity of K562 cells to SAHA.
Apoptosis ; drug effects ; Drug Resistance, Neoplasm ; Drug Screening Assays, Antitumor ; Gene Silencing ; Humans ; Hydroxamic Acids ; pharmacology ; K562 Cells ; RNA, Small Interfering ; genetics ; Ribosomal Proteins ; genetics ; metabolism

OBJECTIVETo probe the effects of dexamethasone (DEX) combined with histone deacetylase (HDAC) inhibitor vorinostat on inhibiting proliferation and inducing differentiation and apoptosis in Kasumi-1 leukemia cells, and its possible mechanisms in order to provide a theoretical basis for the treatment of AML1-ETO positive AML.

METHODSThe cell survival, differentiation and apoptosis rates were tested by MTT or flow cytometry analysis after Kasumi-1 cells were treated by DMSO, DEX (20 nmol/L), vorinostat (1 μmol/L) or DEX (20 nmol/L) in combination with vorinostat (1 μmol/L). WB and IP-WB were performed to detect AML1-ETO and its ubiquitination.

RESULTSTreatment with the combination of DEX and vorinostat for 48 h led to statistically significant differences of inhibited proliferation [(42.06±8.20)%], increased differentiation [(52.83±8.97)%] and apoptosis [(52.92±2.53)%] of Kasumi-1 cells when compared with vorinostat [(33.82±9.41)%, (43.93±9.04)% and (42.98±3.01)%, respectively], DEX [(17.30±3.49)%, (22.53±4.51)% and (19.57±2.17)%, respectively] or control [(6.96±0.39)%, (21.73±2.03)% and (6.96±0.39)%, respectively]. Also significant ubiquitination and decreased AML1-ETO protein in Kasumi-1 cells after the combination treatment over single agent or control were observed.

CONCLUSIONThe results indicated that DEX and vorinostat could synergistically inhibit the Kasumi-1 cells proliferation, induce Kasumi-1 cells differentiation and apoptosis through ubiquitination and degradation of AML1-ETO.

Antineoplastic Agents ; pharmacology ; Apoptosis ; drug effects ; Cell Differentiation ; drug effects ; Cell Line, Tumor ; Core Binding Factor Alpha 2 Subunit ; metabolism ; Dexamethasone ; pharmacology ; Drug Synergism ; Humans ; Hydroxamic Acids ; pharmacology ; Oncogene Proteins, Fusion ; metabolism ; RUNX1 Translocation Partner 1 Protein ; Ubiquitination