p21WAF1基因对人食管鳞癌细胞增殖的抑制作用

目的:探讨p21WAF1( p21)基因转染对食管鳞癌细胞系EC109细胞增殖的影响.方法:根据转染质粒的不同和是否进行质粒转染分为3组.p21转染组:用脂质体Lipofectamine2000介导将pCDNA3.1(+)- p21质粒转染入EC109细胞; 空载体转染组:同样方法将pCDNA3.1(+)-neo质粒转染入EC109细胞; 未转染组:未转染的EC109细胞.应用RTPCR、Western blot分别检测p21基因mRNA、P21蛋白变化; 流式细胞仪分析细胞周期变化,应用MTT、流式细胞仪和透射电镜检测转染外源p21基因对EC109细胞增殖和凋亡的影响.结果:p21转染细胞中p21 mRNA和P21蛋白高表达; p21转染组EC109细胞生长速度低于空载体组和未转染组; 流式细胞仪观察到P21蛋白高表达使EC109细胞发生G1/S阻滞,G1期细胞比例显著高于空载体组和未转染组(63.120%±2.893% vs 41.380%±6.536%,42.173%±5.301%,均P<0.01),S期比例显著低于空载体组和未转染组(18.923%±3.084%vs 22.573%±5.463%,26.867%±2.922%,均P<0.01),并出现亚G1峰(凋亡峰).透射电镜亦发现p21转染组发生细胞凋亡.结论:p21基因转染可以抑制人食管鳞癌细胞系EC109细胞增殖并能诱导其发生细胞凋亡.     

p15INK4B基因转染联合亚砷酸对人食管鳞癌的协同抑制作用

目的探讨p15^INK4B（p15）基因转染与亚砷酸（As2O3）联合应用对人食管鳞癌细胞系EC109细胞增殖和凋亡的影响。方法脂质体介导将pcDNA3．1（＋）-p15转染EC109细胞，稳定筛选后加入2μmol／LAs2O3。PCR检测外源p15基因cDNA，Western印迹法检测转染细胞P15蛋白的表达。用MTT、集落形成实验和透射电镜检测p15基因转染联合As2O3对EC109细胞增殖和凋亡的影响，流式细胞仪检测EC109细胞周期分布和凋亡率。结果与二者单独应用相比，联合应用可明显抑制EC109细胞体外生长速度，集落形成率明显降低（P〈0．01），联合作用3d后发生更为明显的G1／S阻滞，G1期比例显著升高（P〈0．05），S期比例明显降低（P〈0．05），凋亡率明显升高（P〈0．01）。透射电镜发现二者联合应用诱导EC109发生更明显的细胞凋亡。结论p15基因转染与As2O3联合应用可以进一步增强对人食管鳞癌EC109细胞的抑制作用和诱导凋亡作用。     

p21WAF1基因对人胰腺癌细胞系BxPC-3增殖的抑制作用

目的: 探讨p21WAF1( p21)基因转染对人胰腺癌细胞系BxPC-3细胞增殖的影响.方法: 根据转染质粒的不同和是否进行质粒转染分为3组, p21转染组、空载体转染组和未转染组. 应用RT-PCR和Western blot方法检测转染细胞的p21基因表达变化; 流式细胞仪分析细胞周期变化, 用MTT、流式细胞仪和透射电镜检测转染外源p21基因对BxPC-3细胞增殖和凋亡的影响.结果: p21转染组细胞存在p21 mRNA高表达和P21蛋白高表达; p21转染组细胞生长速度低于对照空载体转染组和未转染组; 流式细胞仪观察到P21蛋白高表达使BxPC-3细胞发生G1/S阻滞, G1期细胞比例显著高于空载体组和未转染组(59.887%±3.700% vs 47.443%±6.354%, 49.223%±2.226%, P<0.05), S期显著低于空载体组和未转染组(21.277%±2.080%v s 35.247%±3.966%, 36.013%±1.540%,P<0.01), 并出现亚G1峰(凋亡峰). 透射电镜亦发现p21转染组发生细胞凋亡.结论: p21基因转染可以抑制人胰腺癌细胞系BxPC-3细胞增殖并能诱导其发生细胞凋亡.     

p15~(INK4B)基因对人胰腺癌细胞系BxPC3增殖的影响

目的 探讨p15~(INK4B)(p15)基因转染对人胰腺癌细胞系BxPC3细胞增殖的影响.方法 采用脂质体将pCDNA3.1(+)-p15质粒及阴性对照pCDNA3.1(+)-neo质粒转染BxPC3细胞,以亲本细胞作为对照组.应用RT-PCR检测细胞p15 mRNA表达;Western blotting检测细胞p15蛋白表达;MTT法检测细胞增殖;透射电镜观察细胞超微结构变化;流式细胞仪检测细胞周期和凋亡率.结果 p15转染组细胞恢复p15 mRNA和蛋白表达.培养第2天生长被抑制,至第7天,生长抑制率达47.9%.G_0/G_1期细胞占(61.56±3.96)%,显著高于空质粒转染组的(47.44±6.35)%和对照组的(49.22±7.23)%(P<0.05).出现明显的G,凋亡峰,细胞凋亡率为(5.27±1.04)%,显著高于空质粒转染组的(0.11±0.06)%和对照组的(0.09±0.07)%(P<0.05).透射电镜观察到p15转染组发生细胞凋亡.结论 体外p15基因转染可以抑制人胰腺癌细胞系BxPC3细胞增殖,并能诱导其凋亡.     

siRNA阻断NF-κB信号通路联合5-FU对食管鳞癌细胞凋亡的促进作用

目的: 利用RNAi技术特异性的抑制NF-κB亚单位p65的表达,观察其对p65表达的抑制作用及联合5-FU对食管鳞癌细胞Eca109和EC9706的影响.方法:将终浓度为50 nmol/L的p65 siRNA转染到食管鳞癌细胞EC9706和Eca109中,通过RTPCR检测0、24、48和72 h时段p65 mRNA的表达水平.Western blotting法检测p65和Bcl-2蛋白表达,Annexin V/PI复染结合流式细胞仪检测细胞凋亡,显微镜下观察p65 siRNA与5-FU单独或联合应用对食管鳞癌细胞形态学特性的影响.结果:EC9706和Eca109细胞转染p65 siRNA 24、48和72 h后,p65 mRNA的表达水平随时间的延长逐渐下调,在72 h的阻断效率最为明显,与0 h相比,差异有显著性(0.12±0.01 vs 0.28±0.05,0.1±0.01 vs 0.38±0.04,均P<0.05),转染72 h后,p65和Bcl-2蛋白表达水平下调.EC9706和Eca109转染p65siRNA后,细胞凋亡指数明显升高(6.65%±0.27% vs 2.03%±0.08%,8.03%±0.06% vs 2.66%±0.25%,均P<0.05);p65 siRNA转染72 h后,EC9706和Eca109细胞增殖较慢;当p65 siRNA与5-FU联合作用,细胞增殖明显受到抑制.结论:p65 siRNA可阻断NF-κB信号通路,下调NF-κB下游基因中抗凋亡蛋白Bcl-2的表达,表明活化的NF-κB信号通路可成为食管鳞癌基因治疗中一个重要的分子靶点.     

TGF-β1反义寡核苷酸对食管鳞癌细胞EC9706增殖及凋亡的影响

目的:探讨转染TGF-β1反义寡核苷酸(TGFβ1-ASODN) 对食管鳞癌细胞EC9706 增殖及凋亡的影响. 方法:将化学合成的TGF-β1-ASODN 转染食管鳞癌细胞EC9706,采用RT-PCR 和流式细胞术检测转染效率;观察TGF-β1-ASODN 转染后细胞形态学的改变;采用MTT 和流式细胞术检测TGF-β1-ASODN 转染后对细胞增殖及凋亡的影响. 结果:转染TGF -β1-ASODN 可有效抑制EC9706 细胞中TGF-β1的活性,其mRNA 及蛋白的表达均明显低于转染前的水平(0.25 ±0.07 vs 0.43±0.09;35.35% vs 41.38%,均P<0.05);TGF-β1-ASODN 可明显促进细胞增殖、抑制细胞凋亡,转染后细胞生长拥挤失去正常形态,细胞存活率高于转染前(109.4% vs 100.0%,P <0.05),G1期、S期细胞百分比低于转染前,G2期细胞百分比则高于转染前,细胞凋亡率低于转染前(62.9% vs 66.5%;21.3% vs 23.7%;14.8% vs 9.8%;0.69% vs 0.96%,均P<0.05). 结论:TGF -β1-ASODN 可高效特异地将TGF-β1基因沉默,并解除其抑制细胞增殖、阻滞细胞周期、促进细胞凋亡的作用.     

p15^INK4B基因对人胰腺癌细胞系BxPC3增殖的影响

目的探讨p15^INK4B（p15）基因转染对人胰腺癌细胞系BxPC3细胞增殖的影响。方法采用脂质体将pCDNA3．1（＋）-p15质粒及阴性对照pCDNA3．1（＋）-neo质粒转染BxPC3细胞,以亲本细胞作为对照组。应用RT—PCR检测细胞p15^INK4B表达;Western blotting检测细胞p15蛋白表达;MTF法检测细胞增殖;透射电镜观察细胞超微结构变化;流式细胞仪检测细胞周期和凋亡率。结果p15转染组细胞恢复p15^INK4B和蛋白表达。培养第2天生长被抑制,至第7天,生长抑制率达47．9％。G0／G1期细胞占（61．56±3．96）％,显著高于空质粒转染组的（47．44±6．35）％和对照组的（49．22±7．23）％（P〈0．05）。出现明显的G1凋亡峰,细胞凋亡率为（5．27±1．04）％,显著高于空质粒转染组的（0．11±0．06）％和对照组的（0．09±0．07）％（P〈0．05）。透射电镜观察到p15转染组发生细胞凋亡。结论体外p15基因转染可以抑制人胰腺癌细胞系BxPC3细胞增殖,并能诱导其凋亡。     

HBx基因下调p21对HepG2细胞增殖与凋亡的影响

目的:构建转基因细胞模型HepG2/HBx,观察HBx基因对HepG2细胞增殖、周期和凋亡的影响, 探讨细胞周期蛋白P21在其中的作用和意义.方法:应用脂质体转染和G418筛选构建稳定表达HBx的转基因细胞HepG2/HBx,RT-PCR和Western blot鉴定HBx mRNA与蛋白的表达.分别以四唑蓝(MTT)比色法、流式细胞术检测HepG2/HBx细胞及对照组HepG2与HepG2/pcDNA3.1细胞(转染空载体pcDNA3.1的HepG2细胞)的增殖、周期和凋亡.另半定量RT-PCR检测各组细胞中细胞周期蛋白P21与抑癌基因p53mRNA的表达.结果:HepG2/HBx细胞中有HBx mRNA和蛋白的表达.HepG2/HBx细胞生长速度加快.HepG2/HBx中G0/G1期细胞比例较对照组显著减少(43.34%±3.11%vs57.69±4.28%,P<0.01),S期细胞比例明显增加(28.69%±1.17%vs22.41%±1.99%,P<0.05),同时还发现与对照组相比其凋亡率也显著降低(1.19%±0.06%vs 5.43%±0.42%, P<0.001).细胞周期蛋白p21 mRNA在HepG2/HBx细胞中的表达较对照组细胞显著降低(0.16±0.05vs0.78±0.15,P<0.001),而p53表达则无显著变化.结论:HBx基因可下调细胞周期蛋白P21mRNA的表达,可能参与HBx基因加速HepG2细胞周期进程、促进细胞增殖以及抑制细胞凋亡的作用.     

丹皮酚联合5-FU对食管癌EC9706细胞增殖及凋亡的影响

目的:探讨丹皮酚(paeonol,Pae)单独及联合5-Fu对人食管癌EC9706细胞的增殖抑制及凋亡诱导作用.方法:采用6种浓度的Pae(7.81、15.63、31.25、62.50、125.00、250.00 mg/L)、3种浓度的5-FU(12.50、25.00、50.00 mg/L)及Pae(31.25 mg/L)和5-FU(12.50 mg/L)联合分别处理EC9706细胞24、48、72 h.同时设对照组(细胞不做处理),采用MTT法检测各个时间段细胞的增殖情况:采用流式细胞术检测4种浓度的Pae(31-25、62.50、125.00、250.00 mg/L)处理EC9706细胞72 h后细胞周期的变化:倒置显微镜下观察各Pae组细胞各时间段形态学变化,HE染色光镜下观察凋亡细胞:采用免疫细胞化学法检测经Pae(31.25 mg/L)、5-FU(12.50mg/L)单独和联合作用48 h后细胞中凋亡相关蛋白Bcl-2及Bax的表达.结果:Pae、5-FU可明显抑制EC9706细胞增殖,并随着浓度的增加和作用时间的延长而增强(P<0.05),Pae与5-FU联合用药比单用Pae或5.FU抑制效果更明显(P<0.05);Pae作用后EC9706细胞中G0/G1期和G2/M期细胞比例下降、S期细胞比例上升(Pae 125.00 mg/L组:G0/G1期21.18%±2.28% vs 62.17%±5.23%、G2/M期0.76%±0.54% vs 9.92%±3.10%、S期78.06%±2.82% vs 27.91%±2.13%,均P<0.05):HE染色光镜下可见典型的肿瘤细胞凋亡改变:Pae、5-FU可下调EC9706细胞中Bcl-2蛋白表达,同时增强EC9706细胞中Bax蛋白的表达,联合用药组较单药组作用更为明显(2.21±0.14 vs 5.67±0.30,4.22±0.34;8.55±0.33 vs 3.90±0.27,6.28±0.26,均P<0.05).结论:Pae可明显抑制人食管癌EC9706细胞的增殖.促进其凋亡,Pae联合5-FU作用更为明显.     

曲古菌素A对食管癌EC1细胞增殖和细胞周期的影响及其分子机制

目的:探讨不同浓度曲古菌素A对食管癌细胞系EC1 细胞增殖、细胞周期的影响及其对细胞周期调控基因p21 WAF1/CIP1 表达的影响. 方法:用0.3,0.5,1.0 μmol/L 的TSA 处理EC1 细胞,MTT 检测TSA 作用24 、48 h 对EC1 细胞的抑制作用,流式细胞仪检测0.3,0.5,1.0 μmol/L 的TSA 作用24 h 后EC1 细胞周期的改变,Western blot 法检测p21 WAF1/CIP1 变化. 结果:TSA 在0.5 μmol/L 以上时对EC1 细胞有抑制作用;0.3 μmol/L TSA 处理细胞后细胞周期与对照组相比,无明显变化;0.5 μmol/L TSA 处理EC1 细胞后,G0/G1期细胞较对照组明显增加,S 期细胞较对照组明显减少(74.56% ±1.34% vs 62.12%±0.52%;14.52%±1.81% vs 27.50%±0.66%,均P <0.05);0.5,1.0 μmol/L TSA 处理细胞后p21 WAF1/CIP1 表达明显增加(均P<0.05). 结论:一定浓度的TSA 对人食管癌细胞EC 具有的增殖抑制作用,引起EC1 细胞发生G0/G1 期阻滞,其部分机制与p21 WAF1/CIP1 上调有关.     

Changes of p53 and Waf1p21 and cell proliferation in esophageal carcinogenesis

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Changes in p53 and Waf1p21 expression and cell proliferation in esophageal carcinogenesis

AIM: To study the correlation between changes in p53 and Waf1p21 expression and cell proliferation, determined by proliferating cell nuclear antigen (PCNA), at different stages of human esophageal carcinogenesis.METHODS: Biopsied and resected esophageal tissues from a high risk population of esophageal cancer in northern China were used in this study. All specimens were fixed in 85% alcohol and processed for routine histology. The avidin biotin peroxidase complex (ABC) method was used to detect p53, Waf1p21 and PCNA.RESULTS: Strong nuclear staining of p53, Waf1p21 and PCNA was observed in normal esophageal epithelium and epithelia with different lesion severities. As the lesions progressed to dysplasia (DYS) and to esophageal squamous cell carcinoma (SCC), the Waf1p21 immunoreactivity percentage decreased. The number of Waf1p21-positive cells slightly increased from normal to basal cell hyperplasia (BCH), but did not further increase in DYS and SCC. The total number of Waf1p21-positive cells was lower than the number of p53-positive cells in normal and BCH esophageal epithelia and much lower in DYS and SCC. Waf1p21-positive cells were located in the third and fourth cell layers in half of the samples examined, which was 2-4 cell layers higher than the cells expressing PCNA and p53 in the same histological categories of normal, BCH and DYS.CONCLUSION: Low Waf1p21 levels at the DYS stage may be related to a functional loss of p53. Other mechanisms may also be responsible for the decreased Waf1p21 expression in DYS and SCC.     

Protein p53 and inducer-mediated erythroleukemia cell commitment to terminal cell division.

Inducer-mediated murine erythroleukemia cell (MELC) differentiation provides a model for examining factors determining terminal cell differentiation. The nuclear protein, p53, has been implicated as a potential determinant of cell cycle progression and cell differentiation. In this study p53 content and synthesis, during inducer-mediated MELC differentiation, has been examined with monoclonal antibodies to p53. A decrease in p53 synthesis and content was demonstrated during induced differentiation. As determined by cell cycle fractionation, the decrease in p53 is manifest at all stages of the cell cycle. Hemin, which induces globin mRNA accumulation but not terminal cell division, fails to decrease p53 content. A MELC variant resistant to inducer-mediated commitment to terminal cell division also fails to decrease p53 levels in response to inducers. These experiments suggest that p53 is implicated in MELC cell proliferation and that an induced decrease in p53 may be responsible for G1 phase prolongation and terminal G1 arrest.     

曲古抑菌素A对甲状腺鳞癌SW579细胞株p53和p21表达的影响

目的观察曲古抑菌素A(TSA)对甲状腺鳞癌SW579细胞株生长增殖及p53和p21表达的影响,进而探讨TSA抗甲状腺癌的作用机制。方法体外培养SW579细胞,实验分为DMSO组、TSA组(终浓度为50、100、200、400 nmol/L),采用MTT比色法测定细胞增殖活性;用RT-PCR方法检测SW579细胞p53及p21的mRNA表达;用Western blot方法检测SW579细胞p53及p21的蛋白表达。结果 MTT结果显示,TSA可明显抑制SW579的增殖,并呈剂量依赖性。RT-PCR与Western blot检测结果表明,与未加TSA组比较,TSA组随着浓度的逐渐加大,p21 mRNA和蛋白表达水平明显升高;p53 mRNA表达不变,而p53蛋白表达水平上调。结论 TSA在一定浓度范围内对甲状腺鳞癌细胞株SW579有剂量依赖性地增殖抑制作用,其机制可能与TSA提高SW579细胞p53的表达,进而再上调p21的表达有关。     

Co-transfection of p16(INK4a) and p53 genes into the K562 cell line inhibits cell proliferation

BACKGROUND AND OBJECTIVES: The tumor suppressor genes p53 and p16(INK4a), both of which act in tumor surveillance, are homozygously deleted in the human leukemia cell line K562. This study was performed to assess whether co-transfection of the p16(INK4a) and p53 genes could inhibit K562 cell proliferation. DESIGN AND METHODS: p16(INK4a) and p53 genes were co-transfected into K562 cells with liposome, and the expression of the transfected genes was detected by Western-immunoblotting and immunocytochemistry. The effect of the p16(INK4a) and p53 transfected cell culture was quantified by trypan blue staining, and the number of recovered viable cells was assessed every day after transfection. Cells were analyzed for expression of annexin V in order to detect apoptosis. Differentiation of transfected K562 cells was measured by the benzidine oxidation test, and the cell cycle was analyzed by flow cytometry. RESULTS: After co-transfection, there were 23% and 28% p53 and p16(INK4a) positive cells respectively. Co-transfection with p16(INK4a) and p53 genes significantly inhibited cell proliferation when compared to transfection with either p16(INK4a) or p53 gene. The percentage of cells expressing the apoptosis-related cell surface antigen annexin V was significantly higher in p53 and p16(INK4a) transfected cells than in p53 or p16(INK4a) transfected cells (6.24+/-0.37% vs 4.88+/- 0.17%, p<0.05 and vs 2.78+/-0.26%, p<0.05, respectively). p16(INK4a) and p53 co-transfection significantly increased the number of cells in G1 phase and decreased that in S phase. INTERPRETATION AND CONCLUSIONS: Expression of wild-type p16(INK4a) and p53 genes in K562 cells results in reduced proliferation and apoptosis. Introduction of exogenous p16(INK4a) and p53 genes into K562 cells might contribute to the clinical treatment of leukemia.     

口腔鳞癌组织中 p73、p15蛋白的表达变化及意义

目的：观察口腔鳞癌组织中p73、p15蛋白的表达变化,并探讨其意义。方法采用免疫组化SP法检测20例份口腔正常黏膜组织（对照组）、35例份扁平苔藓组织（扁平苔藓组）、50例份鳞癌组织（鳞癌组）中p73、p15蛋白,并分析鳞癌组中两指标的相关性。结果鳞癌组、扁平苔藓组、对照组p73阳性率分别为82．00％、54．29％、15．00％,p15阳性率分别为42．00％、100．00％、100．00％,两两比较,P均＜0．05;鳞癌组Ⅰ、Ⅱ、Ⅲ级p73阳性率分别为70．83％、90．00％、100．00％,p15阳性率分别为54．17％、35．00％、16．67％,两两比较,P均＜0．05。鳞癌组p73、p15蛋白表达呈负相关（r＝－0．932,P＜0．05）。结论口腔鳞癌组织中p73蛋白表达升高,p15蛋白表达降低,两者在口腔鳞癌发生、发展过程当中起到相互拮抗的作用。     

Mullerian Inhibiting Substance inhibits cervical cancer cell growth via a pathway involving p130 and p107

In addition to causing regression of the Mullerian duct in the male embryo, Mullerian Inhibiting Substance (MIS) inhibits the growth of epithelial ovarian cancer cells, which are known to be of Mullerian origin. Because the uterine cervix is derived from the same Mullerian duct precursor as the epithelium of the ovary, we tested the hypothesis that cervical cancer cells might also respond to MIS. A number of cervical cancer cell lines express the MIS type II receptor, and MIS inhibits the growth of both human papilloma virus-transformed and non-human papilloma virus-transformed cervical cell lines, with a more dramatic effect seen in the latter. As in the ovarian cancer cell line OVCAR8, suppression of growth of the C33A cervical cancer cell line by MIS is associated with induction of the p16 tumor suppressor protein. However, in contrast to OVCAR8 cells, induction of p130 and p107 appears to play an important role in the inhibition of growth of C33A cells by MIS. Finally, normal cervical tissue expresses the MIS type II receptor in vivo, supporting the idea that MIS could be a targeted therapy for cervical cancer.     

Abnormal cell proliferation and p52/p35-CSK expression in the colons of aging rats

In rodents and in humans, aging is associated with increased gastrointestinal epithelial cell proliferation and an expanded crypt proliferative compartment similar to that seen in the preneoplastic bowel. We have compared the distribution of a series of cytoskeletal antigens that are modified when colonic cancer cells differentiate in vitro in the colon of young (4–7 month) and aging (22–26 month) Fischer 344 rats. Two such proteins, p52 and p35, (that are increased in cultured senescent cells) differ in their position in the crypt axis and subcellular localization between young and aging rats. In young rats, immunoreactive p52 protein is present solely near the colonic crypt surface epithelium but in aging rats p52 expressing cells are found deeper in crypts. The intracellular localization of p35 also differs markedly in young and aging animals. The distribution of these proteins appears to be a reproducible biomarker of aging. Antigenic changes similar to those observed in aging colons also are seen in crypt cells of patients with ulcerative colitis and in the flat colonic mucosa of patients with adenomatous polyps and colon cancer. The combination of proliferative and differentiation changes suggest that the flat mucosa of the colon of aging rats has preneoplastic features.