Objective To investigate the effects of DNA methyltransferase inhibitor (DNMTi) and histone deacetylase inhibitor (HDCAi) on expression of E-cadherin gene and invasiveness of cholangiocarcinoma cell. Methods According to different treatment, the QBC939 cells were divided into four groups: blank control group, hydralazine group, valproic acid group and hydralazine and valproic acid combined group. After 48 h, the expression of E-cadherin was evaluated by reverse transcription-PCR (RT-PCR), mehtylation specific PCR (MSP) and Western blot, the invasiveness of QBC939 cells was evaluated by Transwell method. Results There was no expression of E-cadherin mRNA and protien in blank control group and valproic acid group. The expressions of E-cadherin mRNA and protien in hydralazine and valproic acid combined group were higher than those in hydralazine group ( P ＜ 0.01), while the invasiveness of QBC939 cells of hydralazine and valproic acid combined group was much lower than that of blank control group, hydralazine group and valproic acid group ( P ＜ 0.01). Conclusion DNMTi and HDACi can synergistically re-express E-cadherin gene and weaken the invasiveness of QBC939 cell, which plays an important part in treatment of cholangiocarcinoma.
Objective To review the relationship between histone modifications and gastrointestinal cancer. Methods Literatures on histone modifications and the relationship between histone modifications and gastrointestinal cancer were collected and reviewed. Results Histone modifications played an important role in the establishment of gene silencing during tumorgenesis. DNA methylation and histone modifications might interact with each other and form a complex network to establish and maintain gene silencing. Restoring gene function silenced by epigenetic changes in cancer had the potential of ‘normalizing’ cancer cells, which was named epigenetic therapy. Epigenetic therapy was very promising in prevention and treatment of gastrointestinal cancer, but many unsolved issues remain which need to be addressed in future studies. Conclusion Histone modifications are associated with the pathogenesis of gastrointestinal cancer. Restoring gene function silenced by epigenetic changes may have a great role in the prevention and treatment of gastrointestinal cancer.
ObjectiveTo explore the effects and molecular mechanisms of histone methylase G9a inhibitor BIX-01294 on apoptosis in esophageal squamous cell carcinoma (ESCC).MethodsMTT assay and Colony-forming Units were adopted to determine the effects of BIX-01294 on the growth and proliferation of ESCC cell lines EC109 and KYSE150. Flow cytometry was used to analyze the apoptosis status of ESCC cells after the treatment of BIX-01294. The effects of BIX-01294 treatment on the expressions of G9a catalytic product H3K9me2, DNA double-strand break (DSB) markers, and apoptosis-related proteins were detected by Western blotting.ResultsBIX-01294 inhibited the growth of EC109 and KYSE150 cells in a dose-dependent manner (P<0.05), and BIX-01294 with the inhibitory concentration 50% (IC50) significantly inhibited the formation of colony (P<0.05). After 24 hours treatment of BIX-01294 (IC50), the apoptosis rate of EC109 cells increased from 11.5%±2.1% to 42.5%±5.4%, and KYSE150 cells from 7.5%±0.9% to 49.2%±5.2% (P<0.05). The expression level of the G9a catalytic product, H3K9me2, significantly decreased (P<0.05); while the expression of the DSB marker γH2AX was dramatically enhanced (P<0.05). We also found that the mitochondrial apoptosis pathway was activated and the expression levels of cleaved caspase3 and cleaved PARP were significantly elevated (P<0.05).ConclusionBIX-01294, the inhibitor of methyltransferase G9a, prompted apoptosis in ESCC cells by inducing DSB damage and activating mitochondrial apoptosis pathway.
Objective To investigate the effects of histone modification on the expression of chemokines in alveolar epithelial typeⅡ cells ( AECⅡ) in a rat model of chronic obstructive pulmonary disease ( COPD) . Methods 20 SD rats were randomly assigned to a normal control group and a COPD group. The rat model of COPD was established by cigarette smoking. Lung histological changes were observed by HE staining. AECⅡ cells were isolated and identified by alkaline phosphatase staining and electron microscopic. The mRNA expressions of monocyte chemoattractant protein ( MCP) -1, IL-8, and macrophage inflammatory protein ( MIP) -2αwere detected by real-time quantitative PCR. The expression of histone deacetylase ( HDAC) 2 was measured by western blot. Chromatin immunoprecipitation ( ChIP) was used todetect H3 and H4 acetylation, and H4K9 methylation in the promoter region of chemokine gene. Results Compared with the control group, the mRNA expressions of MCP-1, IL-8, and MIP-2αin the COPD group increased 4. 48,3. 14, and 2. 83 times, respectively. The expression of HDAC2 protein in the COPD group wassignificantly lower than in the control group ( 0. 25 ±0. 15 vs. 0. 66 ±0. 15, P lt; 0. 05) . The expression of HDAC2 had a negative correlation with the gene expressions of IL-8, MCP-1, and MIP-2α( r = - 0. 960,- 0. 914, - 0. 928, respectively, all P lt;0. 05) . The levels of H3 and H4 acetylation were higher, and H4K9 methylation level was lower in the promoter region of chemokine gene in the COPD group compared with the control group ( all P lt; 0. 05) . Conclusions MCP-1, IL-8, and MIP-2α participate and promote the lung inflammatory response in COPD. HDAC2-mediated histone modification may play an important role in COPD inflammation.
ObjectiveTo investigate the protective effects and mechanism of selective histone deacetylases 6 (HDAC6) inhibitor 23BB in myoglobin-induced proximal tubular cell lines (HK-2).MethodsHK-2 cells were divided into 5 groups, including control group, myoglobin (200 μmol/L) group, myoglobin (200 μmol/L)+23BB (1.25 nmol/L) group, myoglobin (200 μmol/L)+4-phenylbutyric acid (2 mmol/L) group, and myoglobin (200 μmol/L)+23BB (1.25 nmol/L)+tunicamycin (25 ng/mL) group. Cells were collected at 24 hours after treatment. The endoplasmic reticulum (ER) stress-related gene mRNA level and marker protein expression were evaluated by RT-PCR and Western blotting, including glucose regulated protein 78 (GRP78), C/EBP homology protein (CHOP), inositol-requiring enzyme 1 (IRE1), PKR-like ER kinase (PERK), and activating transcription factor 6.ResultsIn in vitro study, ER stress-related mRNA of GRP78, IRE1α, PERK, and CHOP and marker protein expression of GRP78 and CHOP were found to increase in response to myoglobin treatment. Either administration of 23BB or 4-PBA could alleviate myoglobin-induced these changes.ConclusionThe protective effect of HDAC6 inhibitor 23BB is through the inhibition of myoglobin-induced ER stress in HK-2 cells.
ObjectiveTo summarize mechanism of DNA methylation and histone methylation in liver fibrosis.MethodThe literatures on the DNA methylation and histone methylation during the liver fibrosis were reviewed and analyzed.ResultsThe DNA methylation and histone methylation were the important components of epigenetics. The up-regulation or down-regulation of genes during the liver fibrosis leaded to the activation or inactivation of the subsequent pathways. For example, the PTEN, SEPT9, Smad7, etc. were hypermethylated and the expressions were decreased in the liver fibrosis. The Spp1 was hypomethylated and the expression was increased in the liver fibrosis.ConclusionsMethylation affects expression of genes by altering epigenetics of genes. Systematic and in-depth study of role and mechanism of methylation in liver diseases provides a new direction and locations for some target treatments for liver disease.
ObjectiveTo investigate the expression of histone deacetylase 2 (HDAC2) in animal model of benign tracheal stenosis, and explore the mechanism of HDAC2 in development of tracheal stenosis.MethodsEighteen rabbits were randomly divided into a blank control group, a model group, and an erythromycin group, with 6 rats in each group. The model group and the erythromycin group underwent tracheostomy, the inner wall of trachea was brushed back and forth with a nylon brush for more than 20 times to induce benign tracheal stenosis. From 7 days before surgery to 9 days after surgery, the model group received gavage with saline, the erythromycin group received gavage with low-dose erythromycin in dose of 15 mg·kg–1·d–1, and the control group did not receive any treatment. On the 10th day after operation, all the rabbits were sacrificed and the trachea was cut to measure the tracheal stenosis. RNA and protein were extracted from the granulation tissue in the stenosis and the relative mRNA expressions of HDAC2, interleukin (IL)-6 and IL-8 in the granulation tissue were detected by real-time fluorescence quantitative PCR. The relative expression of HDAC2 protein was detected by Western blot.ResultsCompared with the blank control group, the tracheal stenosis in the model group was more obvious [(84.60±1.14)% vs.(27.00±6.44)%], the mRNA and protein expressions of HDAC2 were decreased (0.29±0.07 vs. 1.00±0.00, 0.20±0.02 vs. 0.49±0.04), the mRNA expressions of IL-6 and IL-8 were up-regulated (4.22±0.67 vs. 1.00±0.00, 162.72±23.23 vs.1.00±0.00). Compared with the model group, tracheal stenosis in the erythromycin group was relieved [(64.00±12.25)% vs. (84.60±1.14)%], the mRNA and protein expressions of HDAC2 were increased (0.42±0.14 vs. 0.29±0.07, 0.43±0.01 vs. 0.20±0.02), the mRNA expressions of IL-6 and IL-8 were decreased (0.72±0.24 vs. 4.22±0.67, 130.22±7.93 vs. 162.72±23.23). All the differences were statistically significant (all P<0.05). The Pearson correlation coefficient between tracheal stenosis and HDAC2 mRNA relative expression was –0.96 (P<0.05).ConclusionsThe down-regulation of HDAC2 expression in model of benign tracheal stenosis is related to the occurrence and development of tracheal stenosis. The low dose of erythromycin may be used to treat benign tracheal stenosis by up-regulating expression of HDAC2 and thus inhibiting the inflammatory disorder during tracheal injury repair.
Objective To investigate the effects of tobacco smoke exposure on histone deacetylase 2 (HDAC2),interleukin-8(IL-8)and tumor necrosis factor-α(TNF-α)expression in peripheral blood of patients with lung adenocarcinoma and analyze the relationships among them. Methods Seventy-three cases diagnosed as lung adenocarcinoma were collected in the First Affiliated Hospital and Affiliated Tumor Hospital of Guangxi Medical University from April 2014 to March 2015.All patients underwent lung function test preoperatively.Fourteen healthy volunteers without tobacco smoke exposure and chronic obstructive pulmonary disease (COPD)were recruited as healthy control.According to the lung function and tobacco smoke exposure,all cases were divided into four groups,ie. a healthy control group (group A,14 cases),a group without tobacco smoke exposure and COPD(group B,19 cases),a group with tobacco smoke exposure and without COPD(group C,33 cases),and a group with tobacco smoke exposure and COPD(group D,21 cases).The expressions of HDAC2 mRNA,IL-8 mRNA and TNF-α mRNA in peripheral blood mononuclear cells (PBMCs)were detected by real-time polymerase chain reaction (PCR).The contents of IL-8 and TNF-α in serum were detected by ELISA. Results Compared with group A,the HDAC2 mRNA expression in PBMCs had no difference in group B(P>0.05),and was down-regulated significantly in group C and D (P<0.05),which in group D was the most obvious.Compared with group A,the expressions of IL-8 mRNA and TNF-α mRNA in PBMCs and the contents of IL-8 and TNF-α in serum were significantly higher in all lung adenocarcinoma patients(all P<0.05),and the up-regulation was more obvious in group D.The relative expression of HDAC2 mRNA in PBMCs showed no significant difference with respect to age,gender or TNM stage (P>0.05).IL-8 and TNF-α in PBMCs and serum showed no significant difference with respect to age and gender (P>0.05),and were higher in the patients with TNM stage Ⅲ lung adenocarcinoma than those with stage Ⅰ and Ⅱ(P<0.05),with no obvious difference between stage Ⅰ and stage Ⅱ (P>0.05). Conclusion Tobacco smoke exposure causes lower expression of HDAC2 and over-expression of IL-8 and TNF-α in peripheral blood of patients with lung adenocarcinoma,can aggravate inflammatory response especially when complicated with COPD,which may be related to the prognosis of lung adenocarcinoma.
Atrial fibrillation is a common arrhythmia associated with high mortality and morbidity, and the current treatment of atrial fibrillation is still limited. Histone deacetylase (HDAC) plays an important role in the pathophysiology of cardiovascular disease and promotes the occurrence of atrial fibrillation. Inhibition of HDAC may be a new therapeutic strategy through the regulation of atrial remodeling. Therefore, we reviewed the research progress of the HDAC and atrial fibrillation.
ObjectiveTo investigate the neuroprotective effects and mechanisms of selective histone deacetylases inhibitor MS-275 on rats after seizures. MethodsA total of 75 rats were randomly divided into 5 groups for treatment:control group,pilocarpine group, treatment group Ⅰ(administered with MS-275, 20mg/kg, once a day,intraperitoneally in 7 consecutive days), treatment group Ⅱ(administered with MS-275, 40mg/kg, once a day, intraperitoneally in 7 consecutive days), MS-275 pretreatment group. We used lithium and pilocarpin to induce seizures. Behaviors of rats in each group were observed. At 72 hours after seizures, Nissl staining and immunohistochemical were respectively used to evaluate the loss of neurons and histone acetylation levels of hippocampal CA1 and CA3 regions in each group. Escape latency in the control group, treatment group Ⅰ, treatment group Ⅱ and MS-275 pretreatment group were longer than pilocarpine group(P<0.05). ResultsCompared with the pilocarpine group, rats in MS-275 pretreatment group could delay pilocarpine-induced seizures and reduce mortality (P<0.05). Degree of neuronal loss and degeneration in both treatment group Ⅰ and treatment group Ⅱ were reduced compared with the pilocarpine group (P<0.05) and the level of histone acetylation in hippocampal CA1 and CA3 regions of the rats were increased compared with the pilocarpine group (P<0.05). ConclusionHDACs inhibitors MS-275 can improve the neuronal damage, histone deacetylation of rats' brain and rats cognitive decline, which can exert an neuroprotective effect on rats after seizures, whose mechanism may be related to its antiinflammatory effect.