新型维甲酸衍生物诱导NB4细胞分化的初步研究

目的:本研究探讨10种新型维甲酸衍生物对白血病细胞株NB4的抑制增殖和诱导分化活性。方法:维甲酸类衍生物作用于NB4细胞后,通过MTT法检测细胞的增殖。瑞氏染色法在倒置相差显微镜下观察加药处理前后细胞形态学变化。NBT还原实验法分析细胞的分化指标。FCM检测分析细胞周期和细胞表面分化抗原变化。结果:维甲酸衍生物作用3 d后,抑制细胞增殖作用呈剂量依赖效应。10种维甲酸衍生物(10-5mol/L)的诱导分化活性表现在油镜下观察NB4细胞向粒系分化成熟的改变,NBT阳性细胞率增加,细胞表面分化抗原CD11b表达量增加,CD13表达则减少。通过对细胞周期的分析,发现G0/G1期细胞表达量增加,呈G1期阻滞。结论:维甲酸衍生物2a-03,4a-02和5a-02显示有较强的诱导NB4细胞分化的活性。     

全反式视黄酸促进胚胎神经干细胞诱导分化的研究

目的本研究观察全反式视黄酸（atRA）对于体外分离培养的胚胎神经干细胞（ENSCs）生长增殖和诱导分化的作用及其可能的分子机制。方法分离培养孕15dSD大鼠（E15 d SD Rattus）海马回ENSCs,采用不同组合成分的神经干细胞培养基培养ENSCs,利用MTF法检测其对于ENSCs存活和增殖的影响;采用不同组合成分的神经细胞诱导分化培养基培养ENSCs,利用细胞免疫荧光染色法鉴定ENSCs及atRA对于其诱导分化的影响。结果MTT实验结果表明,atRA^＋组、atRA^-组和DMSO组均出现ENSCs的增殖效果,而对照组则没有明显的增殖现象,其中atRA^-组最明显,DMSO组次之,atRA^＋组最弱。AtRA^＋组与atRA^-的ENSCs经过诱导分化后产生的神经细胞类型有较明显差异,并且atRA组处理产生的神经元是对照组的3倍左右。结论atRA能够抑制ENSCs的增殖,并且抵消神经生长因子对于ENSCs的促进有丝分裂作用,atRA还可以促进ENSCs定向诱导分化为神经元。     

全反式维甲酸诱导人急性早幼粒白血病HL-60细胞分化的机制

目的研究全反式维甲酸诱导人急性早幼粒白血病HL-60细胞分化机制。方法用流式细胞仪分析维甲酸对HL-60细胞周期变化的影响，用自制的含9 984个已知基因和EST的高密度基因芯片检测HL-60细胞在维甲酸诱导作用下不同时期的基因表达变化。结果HL-60细胞在1 μmol·L^-1维甲酸持续作用2,4和6 d时,流式细胞仪结果显示48%～73%细胞阻断在G0/G1期;基因表达谱分析发现,黏附分子、组织重建蛋白、转运蛋白、核蛋白体蛋白和涉及氧化酶激活途径的基因表达明显升高。结论基因表达谱的研究结果表明,维甲酸作用HL-60细胞与氧化酶激活途径及组织重建蛋白的表达相关联,并揭示了一些已知和未知功能的基因在HL-60细胞分化与细胞凋亡过程中的作用。     

Auranofin promotes retinoic acid- or dihydroxyvitamin D3-mediated cell differentiation of promyelocytic leukaemia cells by increasing histone acetylation

BACKGROUND AND PURPOSE: To investigate the molecular mechanism for the effect of auranofin on the induction of cell differentiation, the cellular events associated with differentiation were analysed in acute promyelocytic leukaemia (APL) cells. EXPERIMENTAL APPROACH: The APL blasts from leukaemia patients and NB4 cells were cotreated with auroanofin and all-trans-retinoic acid (ATRA) at suboptimal concentration. The HL-60 cells were treated with auroanofin and a subeffective dose of 1alpha,25-dihydroxyvitamin D3 (1,25(OH)2 vit D3) in combination. The effect of auroanofin was investigated on histone acetylation at the promoter of differentiation-associated genes and expression of cell cycle regulators. KEY RESULTS: Treatment with auroanofin and ATRA cooperatively induced granulocytic differentiation of fresh APL blasts isolated from patients and NB4 cells. The combined treatment also increased reorganization of nuclear PML bodies and histone acetylation at the promoter of the RARbeta2 gene. Auroanofin also promoted monocytic differentiation of the HL-60 cells triggered by subeffective concentration of 1,25(OH)2 vit D3. The combined treatment of auroanofin and 1,25(OH)2 vit D3 stimulated histone acetylation at p21 promoters and increased the accumulation of cells in the G0/G1 phase. Consistent with this, the expressions of p21, p27 and PTEN were increased and the levels of cyclin A, Cdk2 and Cdk4 were decreased. Furthermore, the hypophosphorylated form of pRb was markedly increased in cotreated cells.Conclusions and implications:These findings indicate that auroanofin in combination with low doses of either ATRA or 1,25(OH)2 vit D3 promotes APL cell differentiation by enhancing histone acetylation and the expression of differentiation-associated genes.     

New synergistic combinations of differentiation inducing agents in the treatment of acute myeloid leukaemia

Summary Differentiation inducing agents in double and triple combinations can induce differentiation in primary culture of more than 80% of blast cells from some AML patients. In the present study, the interactions between these differentiating agents have been analysed using Berenbaum's general algebraic solution and three new, potentially clinically useful synergistic combinations: have been identified all trans retinoic acid (RA) + hexamethylene bisacetamide (HMBA), cytosine arabinoside (Ara-C) + HMBA and RA + Ara-C + HMBA.A measure of the effectiveness of these combinations was that the doses of Ara-C and HMBA required to induce 50% differentiation were decreased about 10-fold and 5-fold, respectively, in combination with 1 M RA.The new synergistic combinations are important not only to limit toxicity but also because multiple drug combinations may better overcome the inherent molecular heterogeneity of the differentiation defect in AML patients. They warrant clinical trial in AML patients who are either unsuitable for or are unresponsive to conventional cytotoxic chemotherapy.     

Auranofin induces apoptosis and when combined with retinoic acid enhances differentiation of acute promyelocytic leukaemia cells in vitro

1. Acute promyelocytic leukaemia (APL) is characterized by a block in differentiation at the promyelocyte stage. Here, we describe the effects of auranofin (AF), a coordinated gold compound, on apoptosis and differentiation of APL cells. 2. Nucleosomal DNA fragmentation assay and Hoechst 33342 staining indicated that AF induced apoptosis in APL-derived NB4 cells at low concentrations (0.5-1.0 microm). The AF-induced apoptosis involved caspase-3 activation and specific cleavage of poly-ADP-ribose polymerase. 3. The AF-treated NB4 cells also produced reactive oxygen species (ROS) and cotreatment with N-acetyl-l-cysteine protected the NB4 cells from AF-induced apoptosis. 4. Expression of the CD11b cell surface marker and C/EBPepsilon was increased when the cells were treated for 4 days with 0.3 microm AF and a physiological concentration of all-trans retinoic acid (ATRA, 5 nm). Treatment with AF in combination with ATRA markedly increased the number of cells with differentiated features, such as lobed or multiple nuclei and numerous granules and vacuoles. At these low concentrations, neither AF nor ATRA alone induced significant cell differentiation. 5. These findings suggest not only that AF induces caspase-3-dependent apoptosis via a mechanism involving ROS, but also that the combined treatment with AF and ATRA induces differentiation of NB4 cells. Our results demonstrate a novel characteristic of AF from which an effective drug treatment of APL might be developed.     

塞来昔布联合维甲酸对SW620细胞增殖和凋亡的影响

目的:探讨塞来昔布联合全反式维甲酸抑制结肠癌SW620细胞增殖和促进凋亡的作用及机制。方法:不同浓度塞来昔布和全反式维甲酸作用SW620细胞48或72 h后应用MTT法和流式细胞仪分别检测细胞的增殖抑制和凋亡率,Western Blot检测细胞AKT、p-AKT及survivin的表达。结果:与单药作用相比,塞来昔布和全反式维甲酸联合作用可明显增强对SW620的增殖抑制和促进凋亡作用(P均<0.01)。Western Blot提示全反式维甲酸和塞来昔布联合作用SW620细胞可抑制AKT活性,下调p-AKT和survivin蛋白表达。结论:塞来昔布在抑制结直肠癌细胞增殖和促进其凋亡中与全反式维甲酸起协同作用,抑制AKT磷酸化、阻断PI3K/Akt通路和下调survivin是其可能作用机制。此结果有望为临床提供可行的联合用药方案,推广维甲酸的诱导分化和凋亡治疗。     

维甲酸受体为靶点的高通量药物筛选细胞模型的建立维甲酸受体为靶点的高通量药物筛选细胞模型的建立

目的建立绿色荧光蛋白(GFP)标记的以维甲酸受体为靶点的高通量药物筛选细胞模型，用于筛选治疗急性早幼粒细胞白血病(APL)、银屑病、痤疮以及肿瘤的新型药物。方法用分子生物学的方法，构建含有8个串连维甲酸受体应答元件(RARE)并连接报告基因E-GFP的重组载体。将体外培养的细胞株用该重组载体进行稳定转染，然后进行单克隆培养，最终挑选出敏感、高效、稳定表达的单克隆细胞，用于筛选针对维甲酸受体的小分子有机药物。结果建立了高效的药物筛选细胞模型。此模型筛选方法简便，适用范围广，灵敏度高，结果稳定。结论挑选出的细胞株作为药物筛选模型可用于大规模高通量药物筛选。     

维生素A酸诱导分化的人早幼粒白血病细胞系HL-60的呼吸爆发功能

借助于自旋捕集剂DMPO,用电子自旋共振波谱仪直接定量检测了经维生素A酸(RA)诱导的人早幼粒白血病细胞HL—60受12—O—十四烷酰—佛波醇13—醋酸酯(TPA)刺激引起氧消耗爆发性增加(呼吸爆发)时主要产生的活性氧—羟基自由基(·OH).诱导分化的细胞产生·OH的量随刺激剂TPA在反应体系中量的增加(50～400 ng)而增高,并和RA诱导时间相关,在诱导d3达峰值,和硝基蓝四氮唑(NBT)还原反应及细胞生长曲线的时间过程一致.同时用自旋探针CTPO和TEMPOL及加宽剂Crox现察到RA诱导分化的HL—60细胞呼吸爆发过程中消耗细胞外介质中的氧.同样实验条件下,未经诱导的HL—60细胞不具有呼吸爆发功能,而人多形核白细胞(PMN)呼吸爆发时也消耗细胞外介质中的氧,检测到的活性氧自由基主要为超氧化物阴离子(O_2)。     

All-trans retinoic acid induced differentiation of rat mammary epithelial cells cultured in serum-free medium

Retinoids are applied to not only cancer prevention but also cancer chemotherapy by stimulating differentiation of cells. We studied differentiation inducing effect of all-trans retinoic acid (ATRA) by studying proportion of high dense fractions of stem-like cells and the size of S phase fraction in cell cycle. From mammary organoids obtained from 7- to 8-week old F344 female rat mammary gland, we cultured rat mammary epithelial cells (RMEC) and treated physiological doses of 10⁻⁶, 10⁻⁷, and 10⁻⁸ M ATRA from the first day and then cultured for 4, 7, and 14 days. After that, immunostaining was performed using peanut agglutinin (PNA) and anti-Thy-1.1 monoclonal antibody (Thy-1.1) that can be used as markers of differentiation. We separated four different cell subpopulations by flow cytometry: cells negative to both reagents (B-), PNA-positive cells (PNA+), Thy-1.1-positive cells (Thy-1.1+), and cells positive to both reagents (B+). We observed continuous decreases of high dense fractions of stem-like cells (PNA+ subpopulations) for 14 days and as much decreases as high doses of ATRA, which were thought to be proportional to doses of ATRA. We labeled RMEC with bromodeoxyuridine and investigated cell cycle fractions that went through S phase. We observed a tendency of decrease of S phase fraction with time in culture, which is though to be related to continuous decreases of PNA+ subpopulations and inhibitory role of ATRA on cell cycle. These results suggest that physiological doses of ATRA could stimulate differentiation of RMEC and convert stem-like RMEC to differentiated cells in SFM for a relatively long period of 14 days.     

Glabridin inhibits urothelial bladder carcinoma cell growth in vitro and in vivo by inducing cell apoptosis and cell cycle arrest

Glabridin (GLA) has a variety of biological activities and therapeutic effects in cancers. Whereas the effect of GLA on urothelial bladder carcinoma (UBC) cells and its underlying mechanisms remain unknown. The study revealed the effect of GLA on UBC and the potential mechanism of inducing cell apoptosis in vivo and in vitro. After treated with different concentrations of GLA, the cell activity decreased in a time- and dose-dependent manner. The IC₅₀ values of BIU-87 and EJ cells at 48 h were 6.02 μg/ml (18.6 μm) and 4.36 μg/ml (13.4 μm), respectively. Additionally, GLA-induced apoptosis and cycle arrest of BIU-87 and EJ cells in G2 phase. Furthermore, wound healing experiments showed that GLA significantly reduced the migration activities of BIU-87 and EJ cells. Mechanically, GLA obviously increased the expression of BIM, BAK1, and CYCS in both mRNA and protein levels, which led to the activation of the endogenous apoptotic pathway. Finally, GLA remarkably inhibited the growth of UBC tumors in vivo. In summary, GLA inhibited UBC cells growth in vitro and in vivo by inducing cell apoptosis and cell cycle arrest, highlighting that GLA could be utilized as a component to design a novel anti-UBC drug.     

维甲酸诱导分化对SH-SY5Y细胞阿片受体表达的影响

目的研究维甲酸诱导SH-SY5Y细胞分化后对阿片受体表达的影响。方法 1×10-5mol.L-1维甲酸诱导SH-SY5Y细胞分化6天,[3H-diprenorphine]放射性配体受体结合试验确定阿片受体表达量。结果维甲酸诱导分化6天后,与对照细胞比较,SH-SY5Y细胞突起增多增长类似轴突,且细胞间形成明显神经纤维网络,细胞生长明显减慢,阿片受体表达提高1.6倍以上。结论维甲酸明显诱导SH-SY5Y细胞向神经元分化,且分化后细胞阿片受体表达明显上调。     

穿心莲内酯对人食管癌Ec9706细胞增殖和凋亡的影响

目的:探讨穿心莲内酯(AD)对人食管癌Ec9706细胞增殖、克隆形成、细胞周期和细胞凋亡的影响。方法:分别以四甲基偶氮唑蓝(MTT)比色法和平板克隆形成法评价AD对Ec9706细胞增殖和克隆形成的抑制作用;通过流式细胞术、细胞原位凋亡检测(TUNEL)和Annexin·V／PI法观察AD诱导细胞凋亡。结果:AD显著抑制Ec9706细胞的增殖,IC_(50)值为28．6μg·mL~(-1),也显著抑制Ec9706细胞的克隆形成,IC_(50)值为1．7μg·mL~(-1)。AD 30和60μg·mL~(-1)组G_0/G_1期的细胞比例较对照组显著增加[(65．6±1．9)%,(60．5±1．1)% vs．(50．6±0．9)%,P＜0．01],凋亡细胞比例也显著大干对照组[(17．9±2．6)%,(39．4±1．7)％vs．(0．5±0．2)%,P＜0．01]。结论:AD抑制人食管癌Ec9706细胞的增殖和克隆的形成,阻滞细胞周期于G_0/G_1期并诱导细胞凋亡。     

CRABP2对肺癌细胞应答全反式视黄酸及细胞增殖的影响

目的：探讨细胞视黄酸结合蛋白2（CRABP2）对肺癌细胞应答全反式视黄酸（ATRA）及细胞增殖的影响。方法观察两株肺癌细胞95‐D和A549对ATRA 的敏感性。应用小干扰RNA （siRNA）敲低CRABP2的表达,采用CCK‐8和流式细胞术分别检测细胞增殖和周期变化,Western blot检测NF‐κB和丝裂原活化蛋白激酶（MAPKs）信号通路分子的表达。结果 ATRA抑制95‐D和A549细胞增殖,其中95‐D细胞的抑制作用更为明显;而干扰CRABP2的表达则显著降低ATRA对95‐D细胞的抑制作用。干扰CRABP2表达在一定程度上能直接抑制95‐D细胞增殖,增加G1期的细胞比例,减少S期的细胞,降低NF‐κB、应激活化蛋白激酶／c‐JUN氨基末端激酶（SAPK／JNK ）和c‐JUN的磷酸化水平。结论 CRABP2能增强肺癌细胞对 ATRA的敏感性,并且还可能通过调控NF‐κB和SAPK／JNK信号通路促进细胞增殖,提示CRABP2在肿瘤细胞中的双重作用。     

Retinoic acid influences the embryoid body formation in mouse embryonic stem cells by induction of caspase and p38 MAPK/JNK‐mediated apoptosis

Although all‐trans retinoic acid (RA), the oxidative metabolite of vitamin A, is essential for normal development, high levels are teratogenic in many species. RA results in immediate effects on the preimplantation embryo and on blastocyst development in vitro and in vivo. To further elucidate the cellular mechanisms of early postimplantation embryo development induced by RA, we present an embryonic cell line, B5, as a candidate system for the investigation of these processes. We used undifferentiated ES cells as the model, which is from the undifferentiated status to differentiated status [embryoid body (EB) formation] mimicking postimplantation embryo development (egg‐cylinder stage of embryo formation) to clarify the cellular mechanism of action of RA in the implanted blastocysts and cell apoptosis following the series of exposures to differing RA concentrations. Using an in vitro model, we identified the impact of RA on undifferentiated embryonic stem (ES) cells, including inhibition of cell proliferation and induction of cell apoptosis. JNK, P‐38 and caspase activation were shown in the nature of RA‐triggered apoptotic signaling in ES cells. The carry‐on influences of RA on the ES cell were shown in the formation of EB from the pretreated ES cells. RA resulted in apparent impact on undifferentiated ES cells in vitro, with increased numbers of apoptotic cells initially and inhibited cell proliferation, which led to decreased size of EB. The process of EB formation (mimicking the early postimplantation embryo development) is regulated by RA‐induced apoptosis through the activation of caspase and P38 MAPK/JNK pathway. © 2011 Wiley Periodicals, Inc. Environ Toxicol, 2013.     

HPLC-MS/MS法测定NB4细胞培养液中的全反式维甲酸

目的 建立HPLC-MS/MS法测定NB4细胞培养液中全反式维甲酸的浓度。方法 采用ACQUITY UPLCTM BEH C₁₈（50 mm×2.1 mm,1.7 μm）色谱柱,以布洛芬为内标,流动相为乙腈-水（含0.1%乙酸）,体积流量为0.2 mL/min,梯度洗脱方式分离全反式维甲酸,同时采用ESI源负离子检测方式,定量分析时的离子反应分别为m/z 299.2→m/z 255.2（全反式维甲酸）和m/z 205.4→m/z 161.3（内标布洛芬）。结果 全反式维甲酸在2.55~255 ng/mL线性关系良好,定量限为2.55 ng/mL,日内精密度RSD ≤ 10.3%,日间精密度RSD ≤ 12.9%。结论 建立的HPLC-MS/MS法可用于测定NB4细胞含维甲酸的培养液中全反式维甲酸的浓度,以及在加入维甲酸代谢阻断剂时全反式维甲酸浓度的变化。     

全反式维甲酸对前列腺癌细胞生长及其连接蛋白43表达的影响

目的探讨全反式维甲酸（ATRA）对前列腺癌细胞生长增殖的抑制作用及其与连接蛋白（Cx）43之间的关系。方法不同浓度的ATRA处理体外培养的雄激素非依赖性人前列腺癌细胞株PC3后,分别应用光镜、甲基偶氮唑蓝（MTT）法和集落形成试验分析细胞生长和增殖的抑制情况;蛋白质免疫印迹法（Western blot）检测PC3细胞ATRA作用前后Cx43的表达。结果ATRA浓度为（10^-6～10^-4）mol／L时均可有效抑制PC3细胞的增殖（P〈0．05）,光镜下可见细胞凋亡的特征性改变,抑制呈时间-剂量依赖性。ATRA处理前后PC3的Cx43表达量从无到阳性光带出现,且显色带随ATRA浓度增高而增强。结论ATRA能够抑制前列腺癌细胞的生长和增殖,其机制可能通过上调Cx43的表达来实现的。