• Proceedings of the Korean Society of Applied Pharmacology
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• 2003.11a
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• pp.88-88
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• 2003

Cytochrome P-450 3A4 (CYP3A4) is major enzyme in human liver, the role of this is detoxification and metabolizing more than 50% clinical drugs in use. Expression of CYP3A4 is transciptionally regulated by the Pregnenolone X receptor (PXR), of which human form is Steroid and Xenobiotics receptor (SXR). SXR is activated by wide range of endogenous and exogenous compounds, and then induces CYP3A4 gene expression. In the previous study, it has been known that proximal promoter (-864 to +64) does not response to chemical inducers such as pregnenolone 16a-carbonitrile (PCN), Rifampicin, Estrogen in terms of transcription of CYP 3A4 in cultured cells. Here, we developed luciferase reporter gene assay system to detect SXR-based CYP 3A4 transcriptional activity. We have used CYP3A4-Luc plasmid that contains proximal promoter of human CYP3A4 gene upstream of the luciferase gene. We did transient transfection of 3A4-luciferase gene and SXR. In the HepG2 cells transfected with CYP3A4-Luc, when rifampicin treatment was combined with histone deacetylase inhibitor (HDAC Inhibitor), such as Trichostatin A, Hc-toxin and IN 2001 of the luciferase activity was induced 10-20 fold over control.

• Proceedings of the Korea Society of Environmental Toocicology Conference
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• 2003.10a
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• pp.178-178
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• 2003

Cytochrome P-450 3A4 (CYP3A4) is major enzyme in human liver, the role of this Is detoxification and metabolizing more than 50% clinical drugs in use. Expression of CYP3A4 is transciptionally regulated by the Pregnenolone X receptor (PXR), of which human form is Steroid and Xenobiotics receptor (SXR). SXR is activated by wide range of endogenous and exogenous compounds, and then induces CYP3A4 gene expression. In the previous study, it has been known that proximal promoter (-864 to ＋64) does not response to chemical inducers such as pregnenolone 16a-carbonitrile (PCN), Rifampicin, Estrogen in terms of transcription of CYP 3A4 in cultured cells. Here, we developed luciferase reporter gene assay system to detect SXR-based CYP 3A4 transcriptional activity. We have used CYP3A4-Luc plasmid that contains proximal promoter of human CYP3A4 gene upstream of the luciferase gene. We did transient transfection of 3A4-luciferase gene and SXR. In the HepG2 cells transfected with CYP3A4-Luc, when rifampicin treatment was combined with histone deacetylase inhibitor (HDAC Inhibitor), such as Trichostatin A, Hc-toxin and IN 2001 of the luciferase activity was induced 10-20 fold over control.

• BMB Reports
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• v.44 no.3
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• pp.176-181
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• 2011

Inhibiting histone deacetylase (HDAC) activity modulates the epigenetic status of cells, resulting in an alteration of gene expression and cellular function. Here, we investigated the effects of HDAC inhibitors on mouse embryonic stem (ES) cells. The HDAC inhibitors trichostatin A, suberoylanilide hydroxamic acid, sodium butyrate, and valproic acid induced early differentiation of mouse ES cells and triggered induction of heat-shock protein (HSP)70. In contrast, class III HDAC inhibitors failed to induce differentiation or HSP70 expression. Transcriptional upregulation of HSP70 was confirmed by mRNA expression analysis, an inhibitor study, and chromatin immunoprecipitation. HSP70 induction was dependent on the SAPK/JNK, p38, and PI3K/Akt pathways. Differentiation and induction of HSP70 by a subset of HDAC inhibitors was also examined in human ES cells, which suggests that the phenomenon generally occurs in ES cells. A better understanding of the effects of HDAC inhibitors may give more insight into their application in stem cell biology.

• Biomedical Science Letters
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• v.25 no.4
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• pp.293-301
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• 2019

Combination chemotherapy is more effective than mono-chemotherapy and is widely used in clinical practice for enhanced cancer treatment. In this study, we investigated the potential synergistic effects of acetaminophen, a common component in many cold medicines, and romidepsin, a histone deacetylase (HDAC) inhibitor, in the A549 non-small cell lung cancer (NSCLC) cell line. The combination of acetaminophen and romidepsin also exerted significant cytotoxicity and apoptosis induced by activation of caspase-3 on tumor cells in vitro. Moreover, combination therapy significantly induced increased production of chemokines that stimulate migration of activated T-cells into tumor cells. This mechanism can lead to active T-cell mediated anti-tumor immunity in addition to the direct cytotoxic chemotherapeutic effect. Activated T-cells led to enhanced cytotoxicity in drug-treated A549 cells through interaction with tumor cells. These results suggested that the interaction between the two drugs is synergistic and significant. In conclusion, our data showed that the use of romidepsin and low concentrations acetaminophen could induce effective anti-tumor effects via enhanced tumor immune and direct cytotoxic chemotherapeutic responses. The combination of acetaminophen with romidepsin should be considered as a promising strategy for the treatment of lung cancer.

• Genomics & Informatics
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• v.8 no.4
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• pp.185-193
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• 2010

Histone deacetylation and demethylation are epigenetic mechanisms implicated in cancer. Studies regarding the role of modulation of gene expression utilizing the histone deacetylase inhibitor scriptaid and the demethylating agent 5-azacytidine in HL-60 leukemia cells have been limited. We studied the possibility of recovering epigenetically silenced genes by scriptaid and 5-azacytidine in human leukemia cells by DNA microarray analysis. The first group was leukemia cells that were cultured with 5-azacytidine. The second group was cultured with scriptaid. The other group was cultured with both agents. Two hundred seventy newly developed genes were expressed after the combination of 5-azacytidine and scriptaid. Twenty-nine genes were unchanged after the combination treatment of 5-azacytidine and scriptaid. Among the 270 genes, 13 genes were differed significantly from the control. HPGD, CPA3, CEACAM6, LOC653907, ETS1, RAB37, PMP22, FST, FOXC1, and CCL2 were up-regulated, and IGLL3, IGLL1, and ASS1 were down-regulated. Eleven genes associated with oncogenesis were found among the differentially expressed genes: ETS1, ASCL2, BTG2, BTG1, SLAMF6, CDKN2D, RRAS, RET, GIPC1, MAGEB, and RGL4. We report the results of our leukemia cell microarray profiles after epigenetic combination therapy with the hope that they are the starting point of selectively targeted epigenetic therapy.

• Interdisciplinary Bio Central
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• v.3 no.4
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• pp.15.1-15.11
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• 2011

Background: Histone deacetylase (HDAC) 8 is one of its family members catalyzes the removal of acetyl groups from N-terminal lysine residues of histone proteins thereby restricts transcription factors from being expressed. Inhibition of HDAC8 has become an emerging and effective anti-cancer therapy for various cancers. Application computational methodologies may result in identifying the key components that can be used in developing future potent HDAC8 inhibitors. Results: Facilitating the discovery of novel and potential chemical scaffolds as starting points in the future HDAC8 inhibitor design, quantitative structure-activity relationship models were generated with 30 training set compounds using genetic function approximation (GFA) and Bayesian algorithms. Six GFA models were selected based on the significant statistical parameters calculated during model development. A Bayesian model using fingerprints was developed with a receiver operating characteristic curve cross-validation value of 0.902. An external test set of 54 diverse compounds was used in validating the models. Conclusions: Finally two out of six models based on their predictive ability over the test set compounds were selected as final GFA models. The Bayesian model has displayed a high classifying ability with the same test set compounds and the positively and negatively contributing molecular fingerprints were also unveiled by the model. The effectively contributing physicochemical properties and molecular fingerprints from a set of known HDAC8 inhibitors were identified and can be used in designing future HDAC8 inhibitors.

• Journal of Pharmacopuncture
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• v.16 no.4
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• pp.7-13
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• 2013

Objectives: Whether the ultra-highly-diluted remedies used in homeopathy can effectively bring about modulations of gene expressions through acetylation/deacetylation of histones has not been explored. Therefore, in this study, we pointedly checked if the homeopathically-diluted anti-cancer remedy Condurango 30C (ethanolic extract of Gonolobus condurango diluted $10^{-60}$ times) was capable of arresting the cell cycles in cervical cancer cells HeLa by triggering an epigenetic modification through modulation of the activity of the key enzyme histone deacetylase 2 vis-a-vis the succussed alcohol (placebo) control. Methods: We checked the activity of different signal proteins (like $p21^{WAF}$, p53, Akt, STAT3) related to deacetylation, cell growth and differentiation by western blotting and analyzed cell-cycle arrest, if any, by fluorescence activated cell sorting. After viability assays had been performed with Condurango 30C and with a placebo, the activities of histone de-acetylase (HDAC) enzymes 1 and 2 were measured colorimetrically. Results: While Condurango 30C induced cytotoxicity in HeLa cells in vitro and reduced HDAC2 activity quite strikingly, it apparently did not alter the HDAC1 enzyme; the placebo had no or negligible cytotoxicity against HeLa cells and could not alter either the HDAC 1 or 2 activity. Data on $p21^{WAF}$, p53, Akt, and STAT3 activities and a cell-cycle analysis revealed a reduction in DNA synthesis and G1-phase cell-cycle arrest when Condurango 30C was used at a 2% dose. Conclusion: Condurango 30C appeared to trigger key epigenetic events of gene modulation in effectively combating cancer cells, which the placebo was unable to do.

• BMB Reports
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• v.56 no.3
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• pp.178-183
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• 2023

Huntington's disease (HD) is a neurodegenerative disorder, of which pathogenesis is caused by a polyglutamine expansion in the amino-terminus of huntingtin gene that resulted in the aggregation of mutant HTT proteins. HD is characterized by progressive motor dysfunction, cognitive impairment and neuropsychiatric disturbances. Histone deacetylase 6 (HDAC6), a microtubule-associated deacetylase, has been shown to induce transport- and release-defect phenotypes in HD models, whilst treatment with HDAC6 inhibitors ameliorates the phenotypic effects of HD by increasing the levels of α-tubulin acetylation, as well as decreasing the accumulation of mutant huntingtin (mHTT) aggregates, suggesting HDAC6 inhibitor as a HD therapeutics. In this study, we employed in vitro neural stem cell (NSC) model and in vivo YAC128 transgenic (TG) mouse model of HD to test the effect of a novel HDAC6 selective inhibitor, CKD-504, developed by Chong Kun Dang (CKD Pharmaceutical Corp., Korea). We found that treatment of CKD-504 increased tubulin acetylation, microtubule stabilization, axonal transport, and the decrease of mutant huntingtin protein in vitro. From in vivo study, we observed CKD-504 improved the pathology of Huntington's disease: alleviated behavioral deficits, increased axonal transport and number of neurons, restored synaptic function in corticostriatal (CS) circuit, reduced mHTT accumulation, inflammation and tau hyperphosphorylation in YAC128 TG mouse model. These novel results highlight CKD-504 as a potential therapeutic strategy in HD.

• Biomolecules & Therapeutics
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• v.23 no.1
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• pp.31-38
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• 2015

Histone acetylation plays a critical role in the regulation of transcription by altering the structure of chromatin, and it may influence the resistance of some tumor cells to tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) by regulating the gene expression of components of the TRAIL signaling pathway. In this study, we investigated the effects and molecular mechanisms of trichostatin A (TSA), a histone deacetylase inhibitor, in sensitizing TRAIL-induced apoptosis in Caki human renal carcinoma cells. Our results indicate that nontoxic concentrations of TSA substantially enhance TRAIL-induced apoptosis compared with treatment with either agent alone. Cotreatment with TSA and TRAIL effectively induced cleavage of Bid and loss of mitochondrial membrane potential (MMP), which was associated with the activation of caspases (-3, -8, and -9) and degradation of poly (ADP-ribose) polymerase (PARP), contributing toward the sensitization to TRAIL. Combined treatment with TSA and TRAIL significantly reduced the levels of the cellular Fas-associated death domain (FADD)-like interleukin-$1{\beta}$-converting enzyme (FLICE) inhibitory protein (c-FLIP), whereas those of death receptor (DR) 4, DR5, and FADD remained unchanged. The synergistic effect of TAS and TRAIL was perfectly attenuated in c-$FLIP_L$-overexpressing Caki cells. Taken together, the present study demonstrates that down-regulation of c-FLIP contributes to TSA-facilitated TRAIL-induced apoptosis, amplifying the death receptor, as well as mitochondria-mediated apoptotic signaling pathways.

• Molecular & Cellular Toxicology
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• v.2 no.3
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• pp.166-169
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• 2006

Accumulated evidences have established that aberrant regulation of histone deacetylases (HDACs) is one of major causes for development of human malignancies. Mammalian HDACs can be divided into three subclasses consisting of 11 homologous of HDACs and 7 of sirtuins, but little is known about HDAC2 causes for carcinogenesis in solid tumors. Here, in order to investigate the roles of HDAC2 in carcinogenesis of liver cancer progression, we analyzed the expression of HDAC2 in 62 human hepatocellular carcinomas by utilizing Immunohistochemistry. Moderate to strong expression of HDAC2 was found in 54 (87%) out of total 62 tumors. The majority of positive tumors were detected in nucleous, but normal hepatocytes did not express of HDAC2 or showed weak positive staining. Interestingly, we were also noted that HDAC2 expression was appeared to be associated with aggressiveness of the tumors by the fact that HDAC2 expression was observed with significances in high grade tumors (Edmonson grade II, III). Taken together, we found the aberrant expression of HDAC2 in hepatocellular carcinomas, and this suggests that HDAC2 may play an important role in the development of liver cancer.