丁酸钠诱导人骨髓增生异常综合征细胞株SKM-1分化作用中细胞外信号调节激酶通路的改变

本研究探讨细胞外信号调节激酶（ERK）通路在丁酸钠（NaB）诱导人骨髓增生异常综合征细胞株SKM-1分化中的作用,阐明丁酸钠诱导SKM-1细胞分化的分子机制.用Western blot方法检测总ERK和磷酸化ERK的表达水平;将ERK特异性的抑制剂PD98059与丁酸钠联合应用,观察它们对SKM-1细胞生长曲线的影响及分化效应,并用Western blot方法检测P21和组蛋白脱乙酰酶（HDAC）蛋白质的表达水平.结果表明：SKM-1细胞经1mmol/L的丁酸钠作用后,总ERK的表达水平未发生变化,而磷酸化ERK的表达水平下降;丁酸钠及丁酸钠＋PD98059均可以上调P21和HDAC蛋白质的表达水平,且丁酸钠联合PD98059的作用强于丁酸钠单用.结论：ERK通路抑制是丁酸钠诱导SKM-1细胞分化的重要分子机制.     

二甲双胍对SKM-1细胞增殖抑制作用及相关作用机制

目的:探讨二甲双胍对AML-MDS细胞株SKM-1细胞增殖的影响以及相关的机制。方法:采用CCK-8检测细胞增殖;采用流式细胞术检测细胞凋亡和细胞周期;采用蛋白印迹法检测通路蛋白AMPK和周期相关蛋白的表达水平。结果:二甲双胍可抑制SKM-1细胞增殖,该作用依赖于二甲双胍诱导细胞周期G0/G1期停滞而非促进细胞凋亡。G1期相关周期蛋白(CyclinD1、CDK4)表达水平明显下调,而周期抑制蛋白P53、P21CIP1、P27KIP1的蛋白水平上调。此外,与二甲双胍抗肿瘤效应相关的AMPK蛋白磷酸化水平上调。结论:二甲双胍抑制SKM-1细胞增殖活性,这可能与其激活AMPK通路诱导细胞周期停滞有关,但仍需进一步深入研究其相关机制。     

藤黄酸对SKM-1细胞生长抑制作用及其机制

本研究探讨藤黄酸（GA）对骨髓增生异常综合征细胞SKM-1生长抑制和诱导细胞凋亡及其机制。采用MTr比色法检测GA对SKM-1细胞的增殖抑制作用,在光学显微镜下观察细胞形态学变化,流式细胞术检测细胞凋亡和细胞周期分布,RT-PCR检测SKM-1细胞baxmRNA和bcl-2mRNA表达情况。结果表明：GA能明显抑制SKM-1细胞增殖,具有时间和剂量依赖性,其48h的IC50值为0．37μg/ml;GA诱导SKM-1细胞凋亡,具有浓度依赖性,诱导SKM-l阻滞在G0／G1期;显微镜下可见典型的凋亡细胞形态特征;GA可明显下调SKM-1细胞bcl-2mRNA表达和上调baxmRNA表达。结论：GA能诱导SKM-1细胞凋亡,其机制可能与细胞G0／G1期阻滞及bcl-2／bax比率下调有关。     

敲减microRNA-205靶向PTEN抑制食管癌细胞TE1的增殖并促进细胞凋亡

目的:探讨miRNA-205对食管癌细胞株TE1增殖和凋亡能力的影响及其作用机制。方法:实时定量聚合酶链式反应(qRT-PCR)和Western印迹检测正常食管黏膜细胞Het-1A和不同食管癌细胞株(KYSE70,TE12,TE1)中miRNA-205的mRNA及蛋白表达水平。转染miRNA-205抑制剂下调TE1细胞中miRNA-205的表达,采用CCK-8法和流式细胞术检测细胞增殖能力、细胞周期和细胞凋亡情况;Western印迹检测细胞增殖和细胞凋亡相关CDK2,cyclin D1,P21,Bcl-2,cleavedcaspase-3,caspase-3,p-Rb,Rb,p-Akt和Akt的蛋白表达水平。双荧光素酶报告基因分析法预测及验证其可能的靶基因。结果:MiRNA-205在各型食管癌细胞中高表达。沉默miRNA-205后,TE1细胞的增殖能力降低并表现为细胞周期阻滞,而细胞凋亡率显著升高(P0.05)。同时细胞中cyclinD1,CDK2,bcl-2,p-Rb及p-Akt的蛋白表达水平均显著降低,p21及cleaved-caspase-3的蛋白表达水平显著升高。双荧光素酶报告基因分析显示PTEN是miRNA-205的可能作用靶点,TE1中共转染miRNA-205抑制剂和PTENsiRNA可部分逆转miRNA-205介导细胞增殖抑制及凋亡诱导作用。结论:沉默miRNA-205可靶向PTEN抑制食管癌细胞株TE1的增殖,并促进其凋亡,提示miRNA-205可作为食管癌诊疗的一个潜在作用靶点。     

细胞周期蛋白A1对SKM-1细胞增殖的影响及其在骨髓异常增生综合征中的作用

目的:通过小干扰RNA(siRNA)下调Cyclin A1的表达,观察其对骨髓增生异常综合征(MDS)细胞系SKM-1细胞增殖的影响并探讨其作用机制。方法:采用阳离子脂质体转染方法,在SKM-1细胞中转染Cyclin A1的siRNA;转染48 h后收集细胞,应用Western blot及RT-PCR测定转染效率;应用CCK-8方法检测细胞增殖,Western blot及RT-PCR检测Cyclin A1基因沉默前后CDK2、RUNX1、SRSF2基因表达的水平。结果:转染Cyclin A1特异性siRNA 48 h后,Cyclin A1蛋白及mRNA表达水平显著下降(P0.01)。下调Cyclin A1后,SKM-1细胞的增殖受抑,CDK2、RUNX1及SRSF2基因的蛋白及mRNA表达量均下调(P0.05)。结论:Cyclin A1表达下调后,SKM-1细胞的增殖受到抑制,表明Cyclin A1可能是MDS治疗的潜在靶点之一。     

原花青素诱导HL-60细胞分化及其机制的研究

本研究旨在探讨原花青素(proanthocyanidin,PAC)诱导人急性早幼粒细胞白血病细胞株HL-60细胞分化的可能机制。用PAC 20 mg/L处理HL-60细胞24 h,CCK-8法检测细胞生长状况,分析PAC对HL-60细胞的增殖影响;应用光学显微镜观察细胞形态变化,流式细胞术分析细胞周期变化和测定细胞分化抗原CD14、CD11b表达;Western blot检测P21、Cyclin D1和CDK4表达变化。结果表明,PAC 20 mg/L作用HL-60细胞24 h,细胞抑制率明显增高(73.2±1.5)%(P<0.01),髓系细胞分化抗原CD14表达明显增高(P<0.01),CD11b表达稍增高,细胞周期中G0/G1期细胞百分率明显增高(P<0.05),S期细胞明显减少(P<0.01);PAC 20 mg/L与HL-60细胞共培养4 h,部分细胞向成熟阶段细胞分化;PAC 20 mg/L处理HL-60细胞12、24和48 h,P21蛋白表达增加,Cyclin D1和CDK4蛋白表达降低。结论:PAC能抑制HL-60细胞增殖并诱导其分化,细胞周期阻滞于G0/G1,其机制可能与P21蛋白表达上调和Cyclin D1及CDK4蛋白表达下调有关。     

三氧化二砷阻滞人Burkitt淋巴瘤细胞增殖和细胞周期作用及其相关机制

本研究探讨As2O3 对人Burkitt淋巴瘤细胞增殖和细胞周期的影响及相关的分子机制,为As2O3临床应用于Burkitt淋巴瘤的治疗提供依据。以人Burkitt淋巴瘤Namalwa细胞株为模型,用不同浓度As2O3作用不同时间,以MTT法、流式细胞术、RQ—PCR和Western—blot分别检测As2O3对细胞增殖、增殖周期和凋亡发生及细胞周期重要调节基因CyclinE、CDK2和P2I表达的影响。结果表明：As2O3显著抑制Namalwa细胞的生长增殖,并显示明显的浓度和时间依赖性;As20,明显阻滞Namalwa细胞于G1期,并显示明显的量效关系;As2O3诱导Namalwa细胞凋亡,呈现明显的作用浓度和作用时间依赖性;As2O3明显下调Namalwa细胞CyclinE、CDK2基因的转录及蛋白表达,明显上调CDK抑制蛋白P2j基因的转录及蛋白表达,且呈现出浓度依赖性。结论：As2O3明显抑制人Burkitt淋巴瘤细胞株Namalwa的生长增殖,此作用与As2O3阻滞细胞周期于G1期及诱导细胞凋亡有关,而As2O3对细胞周期的阻滞与其下调细胞周期的重要驱动基因CyclinE和CDK2的表达、上调CDK抑制因子P2I基因的表达密切相关。     

和厚朴酚对HL-60细胞增殖抑制作用及其相关机制研究

本研究旨在探讨和厚朴酚（honokiol,HNK）对急性髓系白血病细胞HL-60增殖和凋亡的影响及其作用机制。MTT法检测HNK对HL-60细胞增殖抑制作用。流式细胞术检测细胞周期变化。Annexin V/PI法检测细胞凋亡情况。Western blot检测细胞周期蛋白（cyclins）、细胞周期蛋白依赖性激酶（CDK）、P53、P21、P27、BCL-2、BCLXL、BAX、caspase-3、-9、M APK信号通路蛋白。结果表明：HNK能够抑制HL-60细胞增殖,呈时间剂量依赖性。HNK阻滞HL-60细胞于G0/G1期,S期细胞显著减少（P〈0.05）。HNK作用HL-60细胞24 h后,cyclin D1、cyclin A、cyclin E、CDK2、4、6表达显著下调（P〈0.05）,P53、P21表达显著上调（P〈0.05）。HNK作用24 h后HL-60细胞凋亡增加,活化的caspase-3、-9表达显著增加;BCL-2和BCL-XL表达下调,而BAX表达上调。MAPK亚族P38、JNK表达无明显变化;而M EK1/2-ERK1/2的表达显著下调（P〈0.05）。结论：HNK通过干预M EK1/2-ERK1/2信号通路阻滞HL-60细胞于G0/G1期并诱导HL-60细胞凋亡。     

大蒜素抑制多发性骨髓瘤侧群细胞增殖机制研究

目的:探讨大蒜素对多发性骨髓瘤侧群细胞(side population,SP)增殖的影响及其作用机制。方法:培养RPM I-8226和NCI-H929细胞,应用Hoechst33342染色分析其侧群细胞的含量;对培养的侧群细胞,应用10μg/ml大蒜素处理,采用CCK8法分析大蒜素对侧群细胞增殖的影响,应用平板集落形成法分析大蒜素对侧群细胞集落形成能力的影响,流式细胞术分析大蒜素对侧群细胞周期的影响,Western blot法分析大蒜素对周期相关蛋白cyclin D1、cyclin E、CDK2和CDK4的表达。结果:在RPM I 8226和NCI-H929中均存在有侧群细胞,其所占比例分别为(3.17±0.98)%和(2.65±0.61)%。大蒜素能够呈时间依赖性抑制侧群细胞的增殖并显著抑制集落形成;大蒜素能够抑制周期相关蛋白cyclin D1、cyclin E、CDK2和CDK4的表达并诱导细胞发生G1/S周期阻滞。结论:大蒜素可以抑制多发性骨髓瘤侧群细胞增殖和集落的形成,并可能通过下调细胞周期相关蛋白的表达诱导细胞发生G1/S阻滞。     

丙戊酸钠对Kasumi-1细胞细胞周期的阻滞作用及其机制探讨

目的 研究组蛋白脱乙酰化酶(HDAC)抑制剂丙戊酸钠(VPA)对白血病细胞系Kasnmi-1细胞周期的影响并探讨其分子机制.方法 不同浓度VPA处理Kasumi-1细胞不同时间,碘化丙锭染色流式细胞术分析细胞周期的变化.RT-PCR及Western blot方法 分析细胞周期蛋白D1(cyclin D1)及周期蛋白依赖性激酶抑制因子p21 WAF1/CIP mRNA或蛋白水平变化.结果 ①VPA抑制Kasumi-1细胞的细胞周期,使其阻滞于G0/G1期.3 mmol/L VPA处理3 d,G0/G1期细胞由(50.7±2.8)%上升至(80.7±1.7)%.②以3 mmol/LVPA处理Kasumi-1细胞不同时间,与对照组比较,3 mmol/L VPA组cyclin D1 mRNA表达水平下调;以不同浓度VPA处理Kasumi-1细胞3 d,结果 发现随着VPA药物浓度增加cyclin D1 mRNA表达水平降低,呈现剂量依赖性.③VPA诱导p21WAF1/CIP mRNA表达明显增加,呈现时间及剂量依赖性.不同浓度VPA处理细胞3 d时,随着用药浓度的增加,p21WF1/CIP蛋白相对表达水平增加,3 mmol/L VPA处理细胞2 d与0 d比较,p21 WAF1/CIP蛋白相对表达水平明显增加(2.498±0.240对0).结论 VPA可以通过对cyclin D1及周期蛋白依赖性激酶抑制因子p21WAF1/CIP调节使Kasumi-1细胞周期阻滞于G0/G1期.     

维甲酸诱导HL-60细胞分化中对细胞周期素依赖性激酶活性的影响

目的探讨维甲酸（ＲＡ）对ＨＬ６０细胞的增殖抑制和诱导分化作用与细胞周期素依赖性激酶（ＣＤＫ）活性变化的相关性。方法用５×１０－６ｍｏｌ／Ｌ全反式维甲酸（ＡＴＲＡ）或芳维甲（ＡＥ）处理ＨＬ６０细胞１～４天,在观察细胞生长、四氮唑蓝（ＮＢＴ）还原实验以及细胞周期分析的基础上,用组蛋白Ｈ１激酶活性分析技术检测ＣＤＫ２的活性,免疫沉淀法分析结合于ＣＤＫ２和ＣＤＫ４上的相应的细胞周期素（ｃｙｃｌｉｎ）Ｅ和Ｄ的量。结果ＨＬ６０细胞在ＡＴＲＡ或ＡＥ作用下,细胞增殖减慢,对ＮＢＴ的还原能力明显增强,９０％左右的细胞被阻滞在Ｇ１／Ｇ０期;在Ｇ１到Ｓ期转换过程中起关键作用的ｃｙｃｌｉｎＥ／ＣＤＫ２的活性显著下降,结合于ＣＤＫ４上的ｃｙｃｌｉｎＤ１的量减少。结论ＲＡ抑制ＨＬ６０细胞增殖并诱导其分化可能与ＣＤＫ２和ＣＤＫ４的活性下降有密切关系     

地西他滨联合曲古抑菌素A对MDS细胞株SKM-1作用的体外研究

本研究探讨去甲基化制剂地西他滨（decitabine）和（或）组蛋白去乙酰化酶抑制剂曲古抑菌素A（TSA）对MDS—RAEB细胞株SKM—1的影响及作用机制．用台盼蓝拒染法研究药物对SKM—1细胞生长曲线的影响；用四氮唑蓝还原试验和流式细胞术观察药物对SKM—1细胞分化作用；用Annexin V—FITC标记药物作用后的细胞，了解其早期凋亡的情况；用RT—PCR研究药物作用前后细胞Fas，survivin和P15^INK4B。基因表达的变化。结果表明：decitabine和（或）TSA对SKM—1细胞生长有抑制作用，能促进SKM—1细胞分化，细胞表面CD14、CD11b表达增加，HLA—DR表达减少；decitabine和（或）TSA处理SKM—1细胞后，SKM—1细胞凋亡增加，细胞Fas和P15^INK4B mRNA表达增加，survivin mRNA表达减少。结论：decitabine和TSA均可以促进SKM—1细胞凋亡和分化，可能与Fas、P15^INK4B和survivin基因表达有关，二者联用有协同作用。     

Role of cyclins in cAMP inhibition of glomerular mesangial cell proliferation

MC (mesangial cell) proliferation is closely linked to the progression of glomerular disease. It has been reported that cAMP effectors suppress MC proliferation, inhibiting activation of MAPK (mitogen-activated protein kinase). In fibroblasts, activation of MAPK induces the expression of type D cyclin, whereas, in MCs, this induction has not been shown. In the present study, we explored the effects of cAMP on MAPK and expression of cell-cycle-regulated proteins. PDGF (platelet-derived growth factor) stimulated MAPK activity, up-regulated protein levels of cyclin D1, CDK2 (cyclin-dependent kinase 2) and PCNA (proliferating cell nuclear antigen), decreased the protein level of p27 and increased DNA synthesis. Fsk (forskolin) or PD98059 suppressed PDGF-induced DNA synthesis. Both agents inhibited PDGF-stimulated mRNA and protein expression of cyclin D1 and CDK2. Fsk or PD98059 also inhibited protein expression of PCNA and blocked a decrease in p27 protein. Fsk induced the phosphorylation of Raf-1 at Ser259, which was inhibited by KT5720. These data suggest that cAMP inhibits MC proliferation through inhibition of MAPK activity, and this mechanism partly involves alteration in the levels of cell-cycle-regulated proteins.     

YC-1 [3-(5'-Hydroxymethyl-2'-furyl)-1-benzyl Indazole] exhibits a novel antiproliferative effect and arrests the cell cycle in G0-G1 in human hepatocellular carcinoma cells

This study delineates the antiproliferative activities and in vivo efficacy of YC-1 [3-(5'-hydroxymethyl-2'-furyl)-1-benzyl indazole] in human hepatocellular carcinoma cells. YC-1 inhibited the growth of HA22T and Hep3B cells in a concentration-dependent manner without significant cytotoxicity. YC-1 induced G(1) phase arrest in the cell cycle, as detected by an increase in the proportion of cells in the G(1) phase using FAC-Scan flow cytometric analysis. It was further shown that cGMP, p42/p44 mitogen-activated protein kinase, or AKT kinase-mediated signaling pathways did not contribute to the YC-1-induced effect. Of note, YC-1 induced a dramatic increase in the expression of cyclin-dependent kinase (CDK)-inhibitory protein, p21(CIP1/WAP1), and a modest increase in p27(KIP1). The association of p21(CIP1/WAP1) with CDK2 was markedly increased in cells responsive to YC-1. YC-1 did not modify the expression of cyclin D1, cyclin E, CDK2, or CDK4. In a corollary in vivo study, YC-1 induced dose-dependent inhibition of tumor growth in mice inoculated with HA22T cells. Immunohistochemical analysis revealed an inverse relationship between the staining of p21(CIP1/WAF) and the staining of Ki-67, a cell proliferation marker. Based on the results reported herein, we suggest that YC-1 induces cell cycle arrest and inhibits tumor growth both in vitro and in vivo via the up-regulation of p21(CIP1/WAP1) expression in HA22T cells. Because of this, YC-1 is a potential antitumor agent worthy of further investigation.     

In vitro and in vivo activity of R547: a potent and selective cyclin-dependent kinase inhibitor currently in phase I clinical trials

The cyclin-dependent protein kinases are key regulators of cell cycle progression. Aberrant expression or altered activity of distinct cyclin-dependent kinase (CDK) complexes results in escape of cells from cell cycle control, leading to unrestricted cell proliferation. CDK inhibitors have the potential to induce cell cycle arrest and apoptosis in cancer cells, and identifying small-molecule CDK inhibitors has been a major focus in cancer research. Several CDK inhibitors are entering the clinic, the most recent being selective CDK2 and CDK4 inhibitors. We have identified a diaminopyrimidine compound, R547, which is a potent and selective ATP-competitive CDK inhibitor. In cell-free assays, R547 effectively inhibited CDK1/cyclin B, CDK2/cyclin E, and CDK4/cyclin D1 (K(i) = 1-3 nmol/L) and was inactive (K(i) > 5,000 nmol/L) against a panel of >120 unrelated kinases. In vitro, R547 effectively inhibited the proliferation of tumor cell lines independent of multidrug resistant status, histologic type, retinoblastoma protein, or p53 status, with IC(50)s 相似文献   

Peroxisome proliferator-activated receptor ligands affect growth-related gene expression in human leukemic cells

Peroxisome proliferator-activated receptors (PPARs) are ligand-activated nuclear receptors. Three subtypes of PPARs (alpha, beta, and gamma) have been identified in different tissues. PPAR alpha and PPAR gamma ligands inhibit cell proliferation and induce differentiation in several human cell models. We demonstrated that both PPAR alpha (clofibrate and ciprofibrate) and PPAR gamma ligands (troglitazone and 15 deoxy-prostaglandin J2, 15d-PGJ2) inhibited growth, induced the onset of monocytic-like differentiation, and increased the proportion of G0/G1 cells in the HL-60 leukemic cell line. Moreover, 3 days after the treatment with 2.5 microM 15d-PGJ2, an increase in sub-G0/G1 population occurred, compatible with an induction of programmed cell death. To clarify the mechanisms involved in HL-60 growth inhibition due to the effects of PPAR ligands, we investigated their action on the expression of some genes involved in the control of cell proliferation, differentiation, and cell cycle progression such as c-myc, c-myb, and cyclin D1 and D2. Clofibrate (50 microM), ciprofibrate (50 microM), and 15d-PGJ2 (2.5 microM) inhibited c-myb and cyclin D2 expression, whereas they did not affect c-myc and cyclin D1 expression. Only troglitazone (5 microM) decreased c-myc mRNA and protein levels, besides decreasing c-myb and cyclin D2. The down-regulations of c-myb and cyclin D2 expression represent the first evidence of the inhibitory effect exerted by PPAR ligands on these genes. Moreover, the inhibition of c-myc expression by troglitazone may depend on a PPAR-independent mechanism.     

塞来昔布对人白血病细胞株HL-60细胞增殖及凋亡的影响及其作用机制

本研究旨在探讨塞来昔布（celecoxib）对人急性髓系白血病细胞株HL-60细胞增殖、凋亡的影响及其可能的作用机制。不同浓度塞来昔布作用于HL-60细胞24h后,CCK-8法测定细胞增殖活性,流式细胞技术分析细胞凋亡及细胞周期分布的变化,定量RT—PCR的方法检测细胞周期蛋白DJ、EI及COX-2mRNA的表达。结果表明,不同浓度塞来昔布作用于HL-60细胞24h后,细胞增殖明显受抑,且呈-定的浓度依赖性（r=0．955）,24h的IC50值为63．037μmol／L。塞来昔布可诱导HL-60细胞的凋亡,也呈剂量依赖性（r=0．988）。塞来昔布可使HL-60细胞明显阻滞于G0／G1期,可下调cyclinD1、cyclinE1mRNA的表达。塞来昔布可使细胞COX-2mRNA表达水平降低。结论：塞来昔布呈浓度依赖性抑制HL-60细胞增殖,并可能通过下调cyclinD1、cyclinE1的表达引起细胞G0／G1,期阻滞,下调COX-2的表达诱导细胞凋亡。