视黄酸依赖反义cyclin D1对HL-60细胞增殖和分化的影响及其机制

目的：探讨视黄酸(retinoic acid.RA)及其诱导的反义(anti-sense,AS)cyclin D1对肿瘤细胞的协同抑制增殖与诱导分化效应及其机制。方法：通过构建的含有视黄酸反应元件(retinoic acid response element．RARE)的反义cyclin D1 RNA表达载体pCI-nco/RARE3-TK/Ascyclin D1,使反义cyclin D1的表达可受RA诱导调控。以脂质体转染HL-60白血病细胞后．运用生长曲线、MTT比色法和流式细胞仪分析检测细胞增殖功能，NBT还原实验和透射电镜观测细胞分化状况，western-blot检测p16基因蛋白表达水平。结果：反义cyclin D1转染和未转染的HL-60细胞经RA处理后．生长减慢．细胞被阻滞在G0/G1期．分化能力明显增强，p16基因蛋白表达增加．其中,以反义cyclin D1转染细胞经RA处理后变化更为明显。结论：RA及其诱导的反义cvclin D1可协同抑制HL-60细胞增殖和诱导细胞分化成熟．上调p16基因表达可能是其分子机制之一。     

视黄酸依赖反义cyclin D1对HL-60细胞增殖和分化的影响及其机制

目的 :探讨视黄酸 (retinoicacid ,RA)及其诱导的反义 (anti sense ,AS)cyclinD1对肿瘤细胞的协同抑制增殖与诱导分化效应及其机制。方法 :通过构建的含有视黄酸反应元件 (retinoicacidresponseelement ,RARE)的反义cyclinD1RNA表达载体 pCI neo/RARE3 TK/AscyclinD1,使反义cyclinD1的表达可受RA诱导调控。以脂质体转染HL 60白血病细胞后 ,运用生长曲线、MTT比色法和流式细胞仪分析检测细胞增殖功能 ,NBT还原实验和透射电镜观测细胞分化状况 ,western blot检测p16基因蛋白表达水平。结果 :反义cy clinD1转染和未转染的HL 60细胞经RA处理后 ,生长减慢 ,细胞被阻滞在G0 /G1期 ,分化能力明显增强 ,p16基因蛋白表达增加 ,其中 ,以反义cyclinD1转染细胞经RA处理后变化更为明显。结论 :RA及其诱导的反义cyclinD1可协同抑制HL 60细胞增殖和诱导细胞分化成熟 ,上调p16基因表达可能是其分子机制之一。     

抗CD44单抗A3D8对HL-60细胞Cyclin D1 CDK4 p21 cip1表达的影响*

目的:探讨CD44单克隆抗体A3D8对人急性髓系白血病细胞株HL-60细胞增殖分化影响的分子作用机制.方法:采用FCM、RT-PCR及Western blot方法检测A3D8作用前后HL-60细胞Cyclin D1、CDK4、p21cip1表达的变化.结果:A3D8作用使HL-60细胞发生G0/G1期阻滞.A3D8下调HL-60细胞Cyclin D1及CDK4的表达,上调HL-60细胞p21cip1 mRNA及P21蛋白表达.结论:A3D8抑制HL-60细胞增殖、诱导其分化的分子机制可能与p21cipl表达上调及Cyclin D1、CDK4表达下调有关.     

曲古抑菌素A促进As2O3诱导HL-60细胞分化与分子机制的研究

目的：研究曲古抑菌素A能否促进小剂量三氧化二砷（As2O3）诱导HL-60细胞分化并对其机制进行初步探讨.方法：用MTT实验测定药物对细胞增殖的变化;流式细胞仪检测细胞表面CD11b表达率观察药物对细胞的分化作用; RT-PCR方法检测p21和cyclin D3在mRNA水平的表达变化.结果：HL-60细胞经曲古抑菌素A和（或）小剂量As2O3作用24 h后,联合用药组较单用As2O3组能明显抑制细胞增殖,促进细胞分化,p21在mRNA水平表达增加,cyclin D3在mRNA水平表达降低.结论：曲古抑菌素A能促进小剂量As2O3诱导HL-60细胞的分化,其机制可能与细胞周期蛋白cyclin D3和细胞周期蛋白依赖性激酶抑制剂p21的表达变化有关.     

一种视黄酸可控的绿色荧光蛋白表达研究

目的 成功构建带有视黄酸反应元件(RARE)-TK启动子控制的增强型绿色荧光蛋白(eGFP)报告基因表达载体，并验证该载体转染HL60细胞后全反式视黄酸(ATRA)依赖的eGFP表达。方法 采用常规分子克隆方法构建真核表达载体pRARE—TK—eGFP，经脂质体转染肿瘤细胞；ATRA处理后检测细胞增殖功能变化和经荧光显微镜直接观测eGFP表达变化情况。结果 ATRA处理转染HL60细胞后，eGFP呈视黄酸(RA)时间剂量依赖性表达增高。结论 ATRA可通过RARE调控TK启动子下游的eGFP报告基因表达。     

苯并芘对HELF细胞周期及相关基因表达的影响

背景与目的： 探讨苯并芘(benzo[a]pyrene, BaP)影响人胚肺成纤维细胞(HELF)周期的途径和作用机制。 材料与方法： 用5 μmol/L的BaP处理HELF细胞后,采用细胞计数,流式细胞仪检测BaP对细胞生长和周期的影响,用PCR和Western-blotting检测BaP对细胞周期相关基因mRNA和蛋白的影响。 结果： BaP处理HELF细胞后,显著促进细胞的生长,在处理后第8 d时细胞数目约增加50％(P<0.01),细胞体积增大,促进细胞由G1期向S期和G2/M期的转换。 mRNA和蛋白检测结果显示：BaP处理细胞后可以促进p53、cyclin D1、CDK2、CDK4和p21 mRNA及蛋白的表达(P<0.05或P<0.01),抑制cyclin E mRNA及蛋白的表达(P均<0.01),而对cyclin A和p27 mRNA及蛋白表达没有明显影响(P均>0.05)。 结论： BaP对HELF细胞周期的调控逃脱了p53-p21的关卡作用,而通过诱导cyclin D1、CDK2和CDK4的表达来加快细胞周期的进程,该途径为cyclin A和p27非依赖型。     

流式细胞术对食管癌组织中四种细胞周期调控蛋白的定量检测及意义

目的 探讨细胞周期调控蛋白cyclin E、cyclin D1、CDK4和D27在食管癌的表达及其与食管癌的分化和淋巴结转移的关系。方法 采用流式细胞术对65例食管鳞状细胞癌组织中cyclin E、cyclin D1、CDK4和p27的表达强弱进仃定量检测,结果 用荧光指数F1表示。结果 cyclin E、cyclin D1和CDK4在低分化型鳞癌的表达量显著高于分化型鳞癌(P值分别为0．0275,0．0001和0．0174);而p27在低分化型鳞癌的表达量显著低于分化型鳞癌(P=0．0042)。cyclin D1与cyolin E,cyclin D1与CDK4之间呈显著正相关;而cyclin D1与p27呈显著负相关。4种基因蛋白的表达与淋巴结转移均无相关性。结论 cyclhi E、cyclin D1、CDK4和p27的表达与食管癌的分化密切相关;正负性细胞周期调控蚩白表达的失衡是导致癌变的重要原因之一。     

细胞周期素D1反义寡核苷酸对胃癌细胞株BGC—823的作用

目的：通过基因反义封闭技术体外抑制细胞周期素D1(cyclin D1)的表达，并对胃癌细胞增殖的影响。方法：以胃腺癌BGC-823细胞株为研究对象，采用硫代修饰的cyclin D1反义寡脱氧核苷酸(ASODN)处理BGC-823细胞后，观察cyclin D1 ASODN对BGC-823细胞基因表达及体外增殖活性的影响。结果：MTT法测细胞增殖活性见不同浓度ASODN均能抑制BGC-823细胞增殖，抑制作用在48小时最强。RT-PCR检测结果cyclin D1 mRNA减少。免疫组化S-P法结果cyclin D1蛋白表达明显降低。结论：使用人工合成的cyclin D1 ASODN可以特异性的抑制胃腺癌BGC-823细胞株cyclin D1的表达，从而调控细胞周期，抑制细胞增殖。     

畸胎瘤细胞源性生长因子反义核酸载体对高度恶性人卵巢癌细胞增殖和侵袭的抑制效应及相关机制

目的 观察畸胎瘤细胞源性生长因子(PCDGF)反义核酸载体对高度恶性人卵巢癌细胞株Sw626和A2780增殖和侵袭的抑制效应,并初步探讨其相关机制.方法 采用二苯基溴化四氮唑蓝(MTT)法和Boyden小窒体外侵袭实验,检测PCDGF反义RNA真核表达载体对Sw626和A2780细胞增殖和侵袭能力的影响.采用Western blot技术,检测转染PCDGF反义RNA真核表达载体前后Sw626细胞cyclin D1和CDK4蛋自表达的变化.采用逆转录聚合酶链反应(RT-PCR)和明胶酶谱法,分析PCDGF反义RNA真核表达载体对Sw626细胞基质金属蛋白酶2(MMP-2)表达和活性的影响.结果 与空白对照组相比,PCDGF反义核酸载体转染组Sw626和A2780细胞的增殖抑制率分别为72.9%和70.9%,侵袭能力分别被抑制了62.9%和59.0%.转染组Sw626细胞cyclin D1和CDK4蛋白的表达水平分别为0.38±0.08和0.37±0.13,明显低于空白对照组(0.84±0.11和0.64±0.11,P<0.01).与空白对照组(0.89±0.09)相比,转染组Sw626细胞MMP-2 mRNA的表达水平(0.66±0.11)虽未见降低(P>0.05),但MMP-2酶原的活性被叨显抑制.结论 PCDGF反义核酸可显著抑制高度恶性人卵巢癌细胞株Sw626和A2780的增殖和侵袭能力,并逆转其部分恶性表型,这可能与其能下调cyclin D1和CDK4蛋白的表达并抑制MMP-2酶原的活性有关;PCDGF可以作为卵巢癌治疗的新靶点.     

CyclinD1在视黄醇类化合物诱导骨髓细胞分化中的作用研究

目的 :由细胞周期调控入手探讨视黄醇类化合物诱导骨髓干 /祖细胞分化的分子机制。方法 :选择幼年小鼠骨髓细胞为研究对象 ,采用免疫组化、western blot等实验方法 ,观察 RA或 retinol灌胃给药后对骨髓细胞分化成熟的影响以及周期调控蛋白 cyclin D1及相应基因表达变化情况。结果 :ATRA和 retinol均可刺激骨髓有核细胞增殖活性 ,并诱导干 /祖细胞向粒系分化及粒系的终末分化 ;骨髓细胞 cyclin D1、CDK4和 RB基因表达呈时间剂量依赖性下调 ,而 p16、p2 1蛋白表达上调 ,且 ATRA作用优于 retinol。结论 :RA可能经 p Rb、p16等多因素反馈调节 cyclin D1和 CDK4表达 ,抑或直接同其发生作用 ,进而影响骨髓细胞增殖分化的进程。     

Acteoside inhibits human promyelocytic HL-60 leukemia cell proliferation via inducing cell cycle arrest at G0/G1 phase and differentiation into monocyte

We investigated the in vitro effects of acteoside on the proliferation, cell cycle regulation and differentiation of HL-60 human promyelocytic leukemia cells. Acteoside inhibited the proliferation of HL-60 cells in a concentration- and time-dependent manner with an IC50, approximately 30 microM. DNA flow cytometric analysis indicated that acteoside blocked cell cycle progression at the G1 phase in HL-60 human promyelocytic leukemia cells. Among the G1 phase cell cycle-related proteins, the levels of cyclin-dependent protein kinase (CDK)2, CDK6, cyclin D1, cyclin D2, cyclin D3 and cyclin E were reduced by acteoside, whereas the steady-state level of CDK4 was unaffected. The protein and mRNA levels of CDK inhibitors (cyclin-dependent kinase inhibitors), such as p21(CIP1/WAF1) and p27(KIP1), were gradually increased after acteoside treatment in a time-dependent manner. In addition, acteoside markedly enhanced the binding of p21(CIP1/WAF1) and p27(KIP1) to CDK4 and CDK6, resulting in the reduction of CDK2, CDK4 and CDK6 activities. Moreover, the hypophosphorylated form of retinoblastoma increased, leading to the enhanced binding of protein retinoblastoma (pRb) and E2F1. Our results further suggest that acteoside is a potent inducer of differentiation of HL-60 cells based on biochemical activities and the expression level of CD14 cell surface antigen. In conclusion, the onset of acteoside-induced G1 arrest of HL-60 cells prior to the differentiation appears to be tightly linked to up-regulation of the p21(CIP1/WAF1) and p27(KIP1) levels and decreases in the CDK2, CDK4 and CDK6 activities. These findings, for the first time, reveal the mechanism underlying the anti-proliferative effect of acteoside on human promyelocytic HL-60 cells.     

Validation of cyclin D1/CDK4 as an anticancer drug target in MCF-7 breast cancer cells: Effect of regulated overexpression of cyclin D1 and siRNA-mediated inhibition of endogenous cyclin D1 and CDK4 expression

Summary We have examined the role of cyclin D1 and cyclin-dependent kinase-4 (CDK4) in the cell cycle progression and proliferation of MCF-7 breast cancer cells. Forced expression of cyclin D1 using a tetracycline-regulated expression system, and suppression of endogenous cyclin D1 and CDK4 using small interfering RNA (siRNA) were used to validate this protein complex as a drug target in cancer drug discovery. Overexpression of cyclin D1 increased both phosphorylation of the retinoblastoma gene product (RB) and passage through the G1–S phase transition, resulting in increased proliferation of cells. When cyclin D1 expression was shut off, growth rates fell below those seen in control cell lines transfected with the vector, indicating an increased dependence on this protein for proliferation. Inhibition of endogenous cyclin D1 or CDK4 expression by RNA interference resulted in hypophosphorylation of RB and accumulation of cells in G1. These results support the prevailing view that pharmacological inhibition of cyclin D1/CDK4 complexes is a useful strategy to inhibit the growth of tumors. Furthermore, since MCF-7 cells appear to be dependent on this pathway for their continued proliferation, it is a suitable cell line to test novel cyclin D1/CDK4 inhibitors.     

EXPRESSION OF CYCLIN D1 AND CDK4 IN OSTEOSARCOMA OF THE JAWS

The main cause of the cellular malignant proliferation is the disorder of cell division and growth. The alterations of proteins and genes that involved in this process correlate closely with the occurrence and vicious phenotype of neoplasm. Cyclin D1 and cyclin-dependent kinase 4 (CDK4) regulatory proteins in G1 phase have a direct bearing on carcinogenesis. Presently, gene amplification, overexpression, chromosome inversion andtranslocation of cyclin D1 and CDK4 have been discovered in ma…     

Autocrine and possible intracrine regulation of HL-60 cell proliferation by macrophage colony-stimulating factor

The abnormal expression of macrophage colony stimulating factor (M-CSF) isoforms, i.e. membrane bound M-CSF (m-M-CSF) and intracellular M-CSF (c-M-CSF), and their receptor were reported in some leukemia and tumor cells. Furthermore, the nuclear localization of them may be related to poor prognosis and metastasis, while the mechanism is uncertain. We previously reported that m-M-CSF and its receptor played auto-juxtacrine and adhesion molecule role in human leukemia cell line J6-1. In this paper, we show that HL-60 cells highly express M-CSF and its receptor. The localization of positive reactions was mainly in cytoplasma and nuclear in HL-60 cells. In cytoplasma and nuclear, three isoforms of M-CSF were found with molecular weight (MW) of 20, 16 and 14 kDa, while one type of m-CSF receptor (M-CSFR) was discovered with MW of 120 kDa. Immunoprecipitation assay showed that these ligands could exist separately or binding with their receptor. Monoclonal antibody (McAb) against M-CSF and anti-sense oligodeoxynucleotides (ASON) blocking M-CSF expression inhibited the proliferation of HL-60 cells. McAb and ASON regulated the expression of cyclin D1/E, CDK2/4 and p16. Simultaneous administration of both McAb and ASON inhibited the proliferation of HL-60 cells and modulate the expression of cyclins at greater degrees. Our results suggested an autocrine and possible an intracrine loop of M-CSF/M-CSFR in HL-60 cells.     

Effect of a novel vitamin D3 analog, EB1089, on G1 cell cycle regulatory proteins in HL-60 cells

Progression of cell cycle in eukaryotes is regulated by a series of the cyclin-dependent kinases (CDKs) and cyclin-dependent kinase inhibitors (CDKIs). It has been shown that 1,25(OH)2D3 is able to arrest cell cycle at G1 phase in malignant cells including HL-60 cells. EB1089 is a novel 1,25(OH)2D3 analog that has more potent antileukemic properties with reduced hypercalcemic effect in vitro and in vivo than 1,25(OH)2D3. In the present study, we examined the effect of EB1089 on HL-60 cells at the protein levels of several G1 regulatory proteins. Exposure of HL-60 cells to EB1089 (1x10-8 M) for 3 days showed the G1 block by FACS analysis. The level of p21 was markedly induced in HL-60 cells treated with EB1089 at 24 h, and p27 were progressively increased in a time-dependent manner. The expressions of CDK2 and CDK6 were down-regulated during G1 block of HL-60 cells, and CDK4 is progressively elevated. In addition, level of cyclin D1 was increased in a time-dependent manner, however, no change of cyclin E was noted through the G1 to S traverse. Immunoprecipitation study demonstrated that p27 did not bind to CDK2, CDK4 and CDK6 in EB1089-treated HL-60 cell extracts. In contrast, complexes immunoprecipitated from EB1089-treated HL-60 cells with antibodies CDK2 and CDK6 contained higher amounts of immunodetectable p21 protein compared to untreated HL-60 cells, whereas no detectable change was noted with anti-CDK4 antibody. Furthermore, the kinase activities of CDK2 and CDK6 were decreased while little change was observed in CDK4 activity. These data indicated that p21 protein is a strong candidate for the control of G1 progression in EB1089-treated HL-60 cells, and its major target molecules are CDK2 and CDK6.