HDAC抑制剂丙戊酸对小鼠T淋巴细胞表达细胞因子的影响

目的分析组蛋白去乙酰化酶(HDAC)抑制剂丙戊酸(Valproic acid,VPA)对小鼠T细胞亚群IL-2、IFN-γ和IL-6表达的影响,探讨其抗炎免疫调节作用的机制。方法经VPA处理小鼠淋巴细胞,并在佛波醇酯(PDB)和离子霉素刺激后,以流式细胞术分析CD3+、CD4+和CD8+T细胞表达IL-2、IFN-γ和IL-6的情况。结果淋巴细胞受刺激后,IL-6的表达水平仅稍有提高,而IL-2在CD4+和CD8+T细胞表达率分别为35.49%和5.50%,IFN-γ表达率分别为3.47%和38.60%。经VPA处理后,CD3+T细胞IL-6+、IFN-γ+和IL-6+IFN-γ+的表达均受剂量依赖性抑制(P<0.01)。同样,VPA能够剂量依赖性地降低小鼠CD4+和CD8+T细胞亚群内表达IL-2+、IFN-γ+的细胞比例(P<0.01),对于IL-2+IFN-γ+双阳性细胞的比例也具有明显抑制作用(P<0.01);此外,VPA对CD8+T细胞表达IFN-γ的抑制程度高于CD4+T细胞。结论 HDAC抑制剂VPA通过抑制IL-2和IFN-γ而发挥其抗炎和免疫调节效应。     

微小RNA-513c-5p在宫颈癌中的表达及靶向组蛋白去乙酰化酶1调节宫颈癌细胞迁移和侵袭的机制

目的 探讨微小RNA（miR)-513c-5p在宫颈癌中的表达及靶向组蛋白去乙酰化酶1（HDAC1）调节宫颈癌细胞迁移和侵袭的机制。方法 临床收集宫颈癌患者86例,通过Real-time PCR检测肿瘤组织和癌旁组织中miR-513c-5p水平,分析其与宫颈癌病理特征的关系。通过双荧光素酶报告验证miR-513c-5p靶向HDAC1。将宫颈癌HeLa细胞系分为4组：对照组、类似物(mimic)组、mimic+HDAC1组和HDAC1组。通过质粒转染技术过表达miR-513c-5p和(或)HDAC1。Real-time PCR和Western blotting分别用于检测RNA或蛋白的表达水平。分别通过CCK-8法、细胞划痕实验和Transwell实验检测各组的细胞生长、迁移和侵袭能力。 结果 宫颈癌组织中miR-513c-5p水平显著低于癌旁组织。低水平的miR-513c-5p与更高的局部侵袭、淋巴转移和远端转移有关（P<0.05）。miR-513-5p靶向抑制HDAC1表达。过表达miR-513c-5p显著抑制宫颈癌细胞生长、迁移和侵袭（P<0.05）。过表达HDAC1促进细胞生长、迁移和侵袭（P<0.05）,并且可以逆转miR-513c-5p的抑制作用（P<0.05）。 结论 低水平的miR-513c-5p可能与宫颈癌转移有关,并且miR-513c-5p可通过靶向抑制HDAC1蛋白的表达抑制宫颈癌HeLa细胞生长、迁移和侵袭。     

组蛋白去乙酰化酶抑制剂SAHA诱导骨髓瘤细胞的凋亡

背景：SAHA是一种新型的组蛋白去乙酰化酶抑制剂,目前有关其对多发性骨髓瘤细胞作用的研究还少见报道,而且其诱导细胞凋亡的分子机制还不十分清楚。 目的：观察SAHA对多发性骨髓瘤细胞株U266细胞增殖和凋亡的影响,并分析其可能机制。 方法：采用锥虫蓝拒染法、四氮唑蓝比色法检测SAHA 对U266细胞增殖的影响。AllllexinV和PI染色后应用流式细胞仪检测SAHA 作用U266细胞的凋亡率,Hoechst33342染色法检测凋亡细胞的形态。Western-blot方法检测信号转导通路Ras/Raf/Mek/Erk相关蛋白的表达水平。 结果与结论：锥虫蓝拒染法和四氮唑蓝比色法均显示,SAHA可明显抑制U266细胞增殖,且具有时间剂量依赖性。0.5,2,4 μmol/L SAHA作用U266细胞48 h后,经流式细胞仪检测细胞凋亡率分别为 (17.61±1.30)%,(43.13±3.80)%和(74.01±4.39)%,呈剂量依赖性(P < 0.05)。Hoechst33342染色荧光显微镜下可见,SAHA组细胞胞核出现明显的核固缩、核碎裂,而对照组改变不明显。Western-blot结果显示U266细胞经SAHA处理后,Raf-1和Erk蛋白的磷酸化水平受到明显抑制,药物作用48 h时出现显著降低。提示SAHA抑制多发性骨髓瘤细胞株U266细胞增殖并诱导凋亡,信号转导通路Ras/Raf/Mek/Erk阻断是机制之一。     

Apicidin, a novel histone deacetylase inhibitor, has profound anti-growth activity in human endometrial and ovarian cancer cells

Histone deacetylase inhibitors (HDACIs) can inhibit proliferation, induce cell cycle arrest and stimulate apoptosis of cancer cells. Our purpose was to investigate the antiproliferative effects of a novel HDACI, apicidin, on the Ishikawa endometrial cancer cell line, the SK-OV-3 ovarian cancer cell line and normal human endometrial epithelial cells. Endometrial and ovarian cancer cells were treated with various concentrations of apicidin, and the effects on cell growth, cell cycle, apoptosis and related measurements were investigated. MTT assays showed that all endometrial and ovarian cancer cell lines were sensitive to the growth inhibitory effect of apicidin, although normal endometrial epithelial cells were viable after the treatment with the same doses of apicidin that induced the growth inhibition of endometrial and ovarian cancer cells. Cell cycle analysis indicated that their exposure to apicidin decreased the proportion of cells in S-phase and increased the proportion in G0/G1 and/or G2/M phases of the cell cycle. Induction of apoptosis was confirmed by Annexin V staining of externalized phosphatidylserine and loss of the transmembrane potential of mitochondria. This induction occurred in concert with the altered expression of p21WAF1, p27KIP1, p16, cyclin A, and E-cadherin. Furthermore, apicidin treatment of these cell lines increased acetylation of H3 and H4 histone tails. These results suggest that apicidin exhibits the antiproliferative effects through selective induction of genes related to cell growth, malignant phenotype, and apoptosis. The findings raise the possibility that apicidin may prove particularly effective in the treatment of endometrial and ovarian cancers.     

The significance of strong histone deacetylase 1 expression in the progression of prostate cancer

Song Y H, Shiota M, Tamiya S, Kuroiwa K, Naito S & Tsuneyoshi M
(2011) Histopathology 58 , 773–780 The significance of strong histone deacetylase 1 expression in the progression of prostate cancer Aims: Histone deacetylases (HDACs) play important roles in many types of cancer. Recently, it has been reported that HDAC1 expression in prostate cancer is significantly higher than in benign prostate cell lines and tissues. The expression of HDAC1 in association with the clinicopathological data was investigated to define its functional and pathological roles in prostate cancer. Methods and results: HDAC1 expression was examined immunohistochemically in 148 patients with prostate cancer. Strong expression of HDAC1 in benign prostate glands, high‐grade prostatic intraepithelial neoplasia (PIN) and prostate cancer was observed in 17/148 (11%), 19/71 (27%) and 69/148 (47%) patients. Strong HDAC1 expression was correlated with high Gleason score (P = 0.025) and high pT stage (P = 0.012). Patients with strong HDAC1 expression had higher biochemical recurrence rates (P = 0.0010). Furthermore, strong HDAC1 expression had a significant impact on patient biochemical recurrence rates in multivariate analysis (P = 0.004). Conclusions: These results indicate that overexpression of HDAC1 contributes to progression and poor prognosis in prostate cancer. The findings may play an important role in the emergence of effective new approaches for therapy and prognostic markers of prostate cancer.     

The histone deacetylase inhibitor suberoylanilide hydroxamic acid down-regulates expression levels of Bcr-abl, c-Myc and HDAC3 in chronic myeloid leukemia cell lines

In chronic myelocytic leukemia (CML) the activity of the Bcr-Abl tyrosine kinase is known to activate a number of molecular mechanisms, which inhibit apoptosis. In the present study, we show that the histone deacetylase inhibitor SAHA (suberoylanilide hydroxamic acid) markedly decreases protein expression levels of Bcr-Abl and c-Myc in BV-173 cells, while in K562 cells only a minor decrease of Bcr-Abl protein levels is observed while a considerable reduction of c-Myc protein expression may only be achieved at higher concentrations of SAHA. In addition, we found BV-173 cells to be more sensitive to SAHA-induced apoptosis when compared to K562 cells. Even though earlier reports on SAHA considerably focused on its inhibitory effect on HDAC enzymatic activity, we report herein a significant down-regulation of HDAC3 protein expression levels following treatment with SAHA in BV-173 cells, but not in K562 cells. In conclusion, our results imply a molecular mechanism for SAHA-induced apoptosis in BV-173 cells, which involves decreased protein expression levels of Bcr-Abl, c-Myc and HDAC3.     

A novel histone deacetylase inhibitor, Scriptaid, induces growth inhibition, cell cycle arrest and apoptosis in human endometrial cancer and ovarian cancer cells

Histone deacetylase inhibitors (HDACIs) can inhibit cell proliferation, induce cell cycle arrest, and stimulate the apoptosis of cancer cells. We investigated the effects of a novel HDACI, Scriptaid, on the Ishikawa endometrial cancer cell line, SK-OV-3 ovarian cancer cell line, and normal human endometrial epithelial cells. Endometrial and ovarian cancer cells were treated with various concentrations of Scriptaid, and its effect on cell growth, cell cycle, apoptosis, and related measurements was investigated. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assays showed that all endometrial and ovarian cancer cell lines were sensitive to the growth inhibitory effect of Scriptaid, although normal endometrial epithelial cells were viable after treatment with the same doses of Scriptaid that induced the growth inhibition of endometrial and ovarian cancer cells. Cell cycle analysis indicated that their exposure to Scriptaid decreased the proportion of cells in the S phase and increased the proportion in the G0/G1 and/or G2/M phases of the cell cycle. Induction of apoptosis was confirmed by annexin V staining of externalized phosphatidylserine and loss of the transmembrane potential of mitochondria. This induction occurred in concert with the altered expression of genes related to cell growth, malignant phenotype, and apoptosis. Furthermore, Scriptaid treatment of these cell lines increased acetylation of H3 and H4 histone tails. These results raise the possibility that Scriptaid may prove particularly effective in the treatment of endometrial and ovarian cancers.     

Induction of apoptosis and autophagy in metastatic thyroid cancer cells by valproic acid (VPA)

The present study investigated the effect of valproic acid (VPA) on the inhibition of RET signaling and induction of apoptosis in human thyroid carcinoma cells. VPA inhibited the viability of ARO and WRO cells and also inhibited cyclin D1 and caused caspase-3 cleavage. VPA decreased the level of RET protein and blocked the activation of RET downstream targets including phosphorylated ERK, phosphorylated AKT, and p70S6K/pS6. VPA induced metabolic stress, activated AMP-activated protein kinase and increased autophagic flux. Pharmacological inhibition of autophagy (chloroquine) augmented VPA-inducible cytotoxicity, suggesting that autophagy was protective in VPA-treated cells. VPA has a wide spectrum of activity against human thyroid carcinoma cells, and its cytotoxicity can be augmented by inhibiting autophagy. Expression of VPA molecular targets in metastatic human thyroid carcinoma cells suggests that VPA has a potential to become a thyroid cancer therapeutic agent.     

Efficacy of the dietary histone deacetylase inhibitor butyrate alone or in combination with vitamin A against proliferation of MCF-7 human breast cancer cells

The combined treatment with histone deacetylase inhibitors (HDACi) and retinoids has been suggested as a potential epigenetic strategy for the control of cancer. In the present study, we investigated the effects of treatment with butyrate, a dietary HDACi, combined with vitamin A on MCF-7 human breast cancer cells. Cell proliferation was evaluated by the crystal violet staining method. MCF-7 cells were plated at 5 x 10⁴ cells/mL and treated with butyrate (1 mM) alone or combined with vitamin A (10 µM) for 24 to 120 h. Cell proliferation inhibition was 34, 10 and 46% following treatment with butyrate, vitamin A and their combination, respectively, suggesting that vitamin A potentiated the inhibitory activities of butyrate. Furthermore, exposure to this short-chain fatty acid increased the level of histone H3K9 acetylation by 9.5-fold (Western blot), but not of H4K16, and increased the expression levels of p21^WAF1 by 2.7-fold (Western blot) and of RARβ by 2.0-fold (quantitative real-time PCR). Our data show that RARβ may represent a molecular target for butyrate in breast cancer cells. Due to its effectiveness as a dietary HDACi, butyrate should be considered for use in combinatorial strategies with more active retinoids, especially in breast cancers in which RARβ is epigenetically altered.     

Effects of apicidin, a histone deacetylase inhibitor, on the regulation of apoptosis in H-ras-transformed breast epithelial cells

The cellular susceptibility of cancer cells to histone deacetylase (HDAC) inhibitors is increased by the etopic expression of oncogenic Ras. However, the ability of HDAC inhibitors to regulate the apoptotic pathway in human breast cancer cells is still not completely understood. In this study, the anti-proliferative effects of apicidin were compared in H-ras-transformed human breast epithelial (MCF10A-ras) and non-transformed epithelial (MCF10A) cells. MCF10A-ras cells showed a significantly higher growth rate than MCF10A cells. Apicidin significantly increased the levels of acetylated histone H3 and H4 in both cell lines. Western blot analysis and flow cytometry were used to determine if the anti-proliferative effects of apicidin in MCF10A and MCF10A-ras cells could be mediated by modulating the cell cycle. Apicidin attenuated the expression of cyclin E and CDK2 in MCF10A cells, decreased cyclin D1 and cyclin E levels in MCF10A-ras cells, and increased the levels of CDK inhibitors, p21WAF1/Cip1 and p27Kip1, in both cell lines. Notably, the levels of hyperphosphorylation of the Rb protein levels were lower in the MCF10A-ras cells after apicidin treatment. Studies on the regulation of apoptosis showed that apicidin induces the up-regulation of p53 and the downstream activation of ERK in MCF10A-ras cells. The up-regulation of p53 promoted Bax expression leading to activation of caspases-9 and -6, and eventually to apoptosis in MCF10A-ras cells. In addition, apicidin significantly increased the levels of ERK1/2 phosphorylation in MCF10A-ras cells. Therefore, the apicidin-mediated ERK pathway appears to play an important role in modulating the pro-apoptotic pathway in MCF10A-ras cells.     

弱酸洗脱提取的肿瘤抗原肽致敏的树突状细胞对CTL的体内外激活效应

弱酸洗脱提取小鼠红白血病细胞膜表面肿瘤抗原肽,用于致敏树突状细胞（ｄｅｎｄｒｉｔｉ ｃｅｌｌｓ,ＤＣ）观察其对细胞毒性Ｔ淋巴细胞（ＣＴＬ）的体内外激活效应。方法以ＰＨ３．３的枸橼酸－磷酸盐缓冲液室温下处理ＦＢＬ－３小鼠红白血病细胞５ｍｉｎ,流式细胞术检测洗脱效率,弱酸洗脱的抗原肽经ＳｅｐＰａｋＣ１８柱提取纯化,用于致敏ＤＣ,检测其体外刺激ＣＴＬ细胞株增殖的能力及体内激发特异性抗肿瘤免疫应答的能力。     

Effects of trichostatin A, a histone deacetylase inhibitor, on the regulation of apoptosis in H-ras-transformed breast epithelial cells

This study examined the mechanism for the anti-cancer effects of histone deacetylase (HDAC) inhibitor trichostatin A (TsA) in H-ras-transformed human breast epithelial (MCF10A-ras) cells. The effects of TsA on anti-cancer effects of MCF10A-ras cells were determined by measuring the level of cell cycle regulator expression and apoptotic cell death using Western blotting and flow cytometry analysis, respectively. TsA induced morphological changes, apoptotic cell death and modulation of the cell cycle regulatory proteins in the MCF10A-ras cells. TsA increased the levels of acetylated histone H3 and H4 in MCF10A-ras cells. In addition, TsA markedly down-regulated the expression of cyclin D1 and CDK4, up-regulated the expression of p21WAF1 and p53 and induced cell cycle arrest at the G1 phase in MCF10A-ras cells. The levels of hyperphosphorylation of the Rb protein were lower in MCF10A-ras cells after the TsA treatment. Furthermore, the up-regulation of p53 promoted Bax expression, which led to the activation of pro-caspase-3 and eventually to apoptosis in MCF10A-ras cells. TsA significantly increased the levels of ERK1/2 phosphorylation in MCF10A-ras cells. Overall, the TsA-activated ERK pathway plays an important role in cell cycle arrest and apoptosis through the ERK-dependent induction of p21 in Ras-related human cancer cells.     

Transglutaminase 2 modulates antigen-specific antibody response by suppressing Blimp-1 and AID expression of B cells in mice

Tansglutaminase 2 (TG2) mediates post-translational modifications of proteins that are involved in a variety of biological processes. Previous reports suggest an involvement of TG2 in adaptive immune responses. However, little has been elucidated in this regard. We explored, in this study, the role of TG2 in humoral immune response to keyhole limpet hemocyanin (KLH) using TG2(-/-) C57BL/6 mice. After primary and secondary immunization with KLH, the serum titer of the antigen-specific antibody was higher in the TG2(-/-) mice than in the wild-type mice. Not only the amount of the specific antibody was increased, but also the affinity of the antibody was estimated as higher in these mice. The TG2(-/-) spleen showed an enhanced germinal center response with higher percentages of GL7(+) germinal center B cells and B220(low) CD138(high) plasma cells. In addition, germinal center B cells from TG2(-/-) mice showed an increased expression of B lymphocyte induced maturation protein-1 (Blimp-1) as well as activation-induced cytidine deaminase (AID). Our results, in sum, indicate a regulatory role of TG2 in humoral immune response to a protein antigen, probably by way of modulating the expression level of proteins related to humoral immune reposes.