• Proceedings of the PSK Conference
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• 2003.10b
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• pp.184.1-184.1
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• 2003

HDAC and HAT (histone acetyltransferase) are involved in co-regulation in chromatin remodeling and the functional regulation of gene transcription. Abnormal recruitment of HDAC is related to carcinogenesis. Thus, the identification of potent histone deacetylase (HDAC) inhibitor has been considered as very intriguing approach for development for cancer chemotherapy. More recently, anti-inflammatory activity of SAHA cytokines was reported via reduction of proinflammatory cytokinres in vitro and in vivo. (omitted)

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.12
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• pp.7095-7100
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• 2013

Histone deacetylase (HDAC) inhibitors of cyclic peptide have been proved to be the most complex but the most stable and relative efficient inhibitors because of their large cap region. In this paper, a series of studies were carried out to evaluate the efficacy of synthetic bicyclic tetrapeptide inhibitors 1-5 containing hydroxamic acid referring molecular docking, anti-proliferation, morphology and apoptosis. Docking analysis, together with enzyme inhibitory results, verified the selective capability of inhibitor 4 to HDAC4, which might closely related to haematological tumorigenesis, with Phe227, Asp115, Pro32, His198 and Ser114 participating into hydrophobic interactions and Van der Waals force which was familiar with former study. Moreover, inhibitor 4 inhibited K562 cell line at the $IC_{50}$ value of 1.22 ${\mu}M$ which was 51-67 times more efficient than that for U937 and HL60 cell lines. Inhibitor 4 exhibited the cell cycle-arrested capability to leukemia at S phase or G2/M phase as well as apoptosis-induced ability in different degrees. Finally, we considered that bicyclic tetrapeptide inhibitors were promising inhibitors used in cancer treatment and inhibitor 4 could prevent K562 cell line well from proliferation, arrest cell cycle and induce K562 towards apoptosis to achieve the goals of reversing cancer cells which could become a potential leukemia therapeutic agent in the future.

• Molecules and Cells
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• v.39 no.3
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• pp.229-241
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• 2016

We have previously reported the role of miR-326-HDAC3 loop in anti-cancer drug-resistance. CAGE, a cancer/testis antigen, regulates the response to anti-cancer drug-resistance by forming a negative feedback loop with miR-200b. Studies investigating the relationship between CAGE and HDAC3 revealed that HDAC3 negatively regulated the expression of CAGE. ChIP assays demonstrated the binding of HDAC3 to the promoter sequences of CAGE. However, CAGE did not affect the expression of HDAC3. We also found that EGFR signaling regulated the expressions of HDAC3 and CAGE. Anti-cancer drug-resistant cancer cell lines show an increased expression of $pEGFR^{Y845}$. HDAC3 was found to negatively regulate the expression of $pEGFR^{Y845}$. CAGE showed an interaction and co-localization with EGFR. It was seen that miR-326, a negative regulator of HDAC3, regulated the expression of CAGE, $pEGFR^{Y845}$, and the interaction between CAGE and EGFR. miR-326 inhibitor induced the binding of HDAC3 to the promoter sequences in anti-cancer drug-resistant $Malme3M^R$ cells, decreasing the tumorigenic potential of $Malme3M^R$ cells in a manner associated with its effect on the expression of HDAC3, CAGE and $pEGFR^{Y845}$. The down-regulation of HDAC3 enhanced the tumorigenic, angiogenic and invasion potential of the anti-cancer drug-sensitive Malme3M cells in CAGE-dependent manner. Studies revealed that $PKC{\delta}$ was responsible for the increased expression of $pEGFR^{Y845}$ and CAGE in $Malme3M^R$ cells. CAGE showed an interaction with $PKC{\delta}$ in $Malme3M^R$ cells. Our results show that HDAC3-CAGE axis can be employed as a target for overcoming resistance to EGFR inhibitors.

• BMB Reports
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• v.48 no.3
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• pp.131-138
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• 2015

Cardiac hypertrophy is a form of global remodeling, although the initial step seems to be an adaptation to increased hemodynamic demands. The characteristics of cardiac hypertrophy include the functional reactivation of the arrested fetal gene program, where histone deacetylases (HDACs) are closely linked in the development of the process. To date, mammalian HDACs are divided into four classes: I, II, III, and IV. By structural similarities, class II HDACs are then subdivided into IIa and IIb. Among class I and II HDACs, HDAC2, 4, 5, and 9 have been reported to be involved in hypertrophic responses; HDAC4, 5, and 9 are negative regulators, whereas HDAC2 is a pro-hypertrophic mediator. The molecular function and regulation of class IIa HDACs depend largely on the phosphorylation-mediated cytosolic redistribution, whereas those of HDAC2 take place primarily in the nucleus. In response to stresses, posttranslational modification (PTM) processes, dynamic modifications after the translation of proteins, are involved in the regulation of the activities of those hypertrophy-related HDACs. In this article, we briefly review 1) the activation of HDAC2 in the development of cardiac hypertrophy and 2) the PTM of HDAC2 and its implications in the regulation of HDAC2 activity.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.4
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• pp.2503-2508
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• 2013

Histone deacetylation mediated by histone deacetylases (HDACs) has been reported as one of the epigenetic mechanisms associated with tumorigenesis. The poor responsiveness of anticancer drugs found with cholangiocarcinoma (CCA) leads to short survival rate. We aimed to investigate mRNA expression of HDACs class I and II, and the effect of HDAC inhibitors, suberoylanilide hydroxamic acid (SAHA) and valproic acid (VPA), in CCA in vitro. Expression of HDACs was studied in CCA cell lines (M213, M214 and KKU-100) and an immortal cholangiocyte (MMNK1) by semi-quantitative reverse transcription-PCR. SAHA and VPA, as well as a classical chemotherapeutic drug 5 -fluorouacil (5-FU) were used in this study. Cell proliferation was determined by sulforhodamine assay. $IC_{50}$ and $IC_{20}$ were then analyzed for each agent and cell line. Moreover, synergistic potentional of VPA or SAHA in combination with 5-FU at sub toxic does ($IC_{20}$) of each agent was also evaluated. Statistic difference of HDACs expression or cell proliferation in each experimental condition was analyzed by Student's t-test. The result demonstrated that HDACs were expressed in all studied cell types. Both SAHA and VPA inhibited cell proliferation in a dose-dependent manner. Interestingly, KKU-100 which was less senstitive to classical chemotheraoeutic 5-FU was highly was sensitive to HDAC inhibitors. Simultaneous combination of subtoxic doses of HDAC inhibitors and 5-FU signiicantly inhibited cell proliferation in CCA cell lines compared to single sgent treatment($P{\leq}0.01$), while sequentially combined treatments were less effective. The present study showed inhibitory effects of HDACIs on cell proliferation in CCA cell lines, with synergistic antitumor potential demonstrated by simultaneous combination of VPA or SAHA with 5-FU, suggesting a novel alternative therapeutic strategy in effective treatment of CCA.

• Molecules and Cells
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• v.26 no.1
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• pp.93-99
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• 2008

Transcriptional silencing is regulated by promoter methylation and histone modifications such as methylation and acetylation. We constructed a Schizosaccaromyces pombe reporter strain, KCT120a, to identify modifiers of transcriptional silencing, by inserting the $ura4^+$ gene into a heterochromatic telomere region. Two compounds inhibited the activity of histone deacetylases, induced acetylation of histone H3 and caused apoptotic cell death in HeLa cells. Expression of gelsolin and $p21^{waf1/cip1}$ also increased, as it does in response to HDAC inhibitors such as TSA. Therefore, these compounds appear to be potent inhibitors of HDACs, and hence potential anti-cancer drugs. Our observations suggest that a yeast cell-based assay system for transcriptional silencing may be useful for identifying histone deacetylase inhibitors and other agents affecting chromatin remodeling.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.7
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• pp.3605-3610
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• 2016

Background: Histone acetylation in chromatin structures plays a key role in regulation of gene transcription and is strictly controlled by histone acetyltransferase (HAT) and deacetylase (HDAC) activities. HDAC deregulation has been reported in several cancers. Materials and Methods: The expression of 10 HDACs (including HDAC class I and II) was studied by quantitative reverse transcription-PCR (qRT-PCR) in a cohort of mesenchymal stem cells (MM-MSCs) from 10 multiple myeloma patients with a median age 60y. The results were compared with those obtained for normal donors. Then, a coculture system was performed between MM-MSCs and u266 cell line, in the presence or absence of sodium butyrate (NaBT), to understand the effects of HDAC inhibitors (HDACi) in MM-MSCs on multiple myeloma cases. Also, the interleukin-6 (IL-6) and vascular endothelial growth factor (VEGFA) gene expression level and apoptotic effects were investigated in MM-MSCs patients and control group following NaBT treatment. Results: The results indicated that upregulated (HDACs) and downregulated (IL6 and VEGFA) genes were differentially expressed in the MM-MSCs derived from patients with multiple myeloma and ND-MSCs from normal donors. Comparison of the MM-MSCs and ND-MSCs also showed distinct HDACs expression patterns. For the first time to our knowledge, a significant increase of apoptosis was observed in coculture with MM-MSCs treated with NaBT. Conclusions: The obtained findings elucidate a complex set of actions in MSCs in response to HDAC inhibitors, which may be responsible for anticancer effects. Also, the data support the idea that MSCs are new therapeutic targets as a potential effective strategy for MM.

• Biomolecules & Therapeutics
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• v.20 no.3
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• pp.313-319
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• 2012

In recent years, inhibition of HDACs has emerged as a potential strategy to reverse aberrant epigenetic changes associated with cancer, and several classes of HDAC inhibitors have been found to have potent and specific anticancer activities in preclinical studies. But their precise mechanism of action has not been elucidated. In this study, a novel synthetic inhibitor of HDAC, 3-(4-dimethylamino phenyl)-N-hydroxy-2-propenamide [IN-2001] was examined for its antitumor activity and the underlying molecular mechanisms of any such activity on human breast cancer cell lines. IN-2001 effectively inhibited cellular HDAC activity ($IC_{50}$ = 0.585 nM) inMDA-MB-231 human breast cancer cells. IN-2001 caused a significant dose-dependent inhibition of cell proliferation in estrogen receptor (ER) negative MDA-MB-231human breast cancer cells. Cell cycle analysis revealed that the growth inhibitory effects of IN-2001 might be attributed to cell cycle arrest at $G_0/G_1$ and/or $G_2$/Mphase and subsequent apoptosis in human breast cancer cells. These events are accompanied by modulating several cell cycle and apoptosis regulatory genes such as CDK inhibitors $p21^{WAF1}$ and $p27^{KIP1}$ cyclin D1, and other tumor suppressor genes such as cyclin D2. Collectively, IN-2001 inhibited cell proliferation and induced apoptosis in human breast cancer cells and these findings may provide new therapeutic approaches, combination of antiestrogen together with a HDAC inhibitor, in the hormonal therapy-resistant ER-negative breast cancers. In summary, our data suggest that this histone deacetylase inhibitor, IN-2001, is a novel promising therapeutic agent with potent antitumor effects against human breast cancers.

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.117.3-118
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• 2003

The acetylation of histone is one of the mechanisms involved in the regulation of gene expression and is tightly controlled by two core enzymes, histone acetyltransferase (HAT) and deacetylase (HDAC). There are several reports that imbalance of HAT and HDAC activity is associated with abnormal behavior of the cells in morphology, cell cycle, differentiation, and carcinogenesis. Recently, an increasing number of structurally diverse HDAC inhibitors have been identified that inhibit proliferation and induce differentiation and/or apoptosis of tumor cells in vivo and in vitro. (omitted)

• Proceedings of the Korean Society of Toxicology Conference
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• 2005.05a
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• pp.177-177
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• 2005