脆性组胺酸三联体基因对人肺腺癌A549细胞恶性表型的影响

目的研究外源性脆性组胺酸三联体(FHIT)基因在体内外对人肺腺癌A549细胞恶性表型的影响。方法用脂质体介导外源FHIT基因转染A549细胞,建立单克隆细胞系FHITA-549和PEGFP-A549。逆转录聚合酶链反应(RTPCR)、免疫组化方法检测外源FHIT基因在A549细胞的表达状况。采用细胞生长曲线、集落形成试验、流式细胞仪及裸鼠移植瘤试验研究外源FHIT基因对A549细胞体外增殖、凋亡、细胞周期和体内成瘤性的影响。结果RTPCR试验证实FHIT-A549中有FHITmRNA表达,免疫组织化学染色显示FHIT-A549细胞FHIT蛋白表达强阳性,而A549细胞和转空载体的PEGFPA549细胞FHIT基因和蛋白表达均阴性。FHIT-A549细胞的集落形成率为2.6%,显著低于A549细胞的50.1%和转染空载体PEGFPA549细胞的53.6%,三者相比差异有统计学意义(P<0.01)。流式细胞仪分析显示FHIT-A549细胞95.8%阻滞在G2期。FHITA549细胞移植瘤的瘤重为(0.04±0.03)g,显著低于A549细胞的(0.24±0.11)g和转染空载体PEGFPA549细胞的(0.25±0.07)g,三者差异有统计学意义(P<0.01)。结论A549细胞内外源FHIT基因的转导并表达能显著抑制其恶性增殖和分裂,诱导其凋亡,调节其细胞周期、抑制成瘤性。     

人肺腺癌紫杉醇耐药细胞系DNA polβ的表达

目的建立人肺腺癌紫杉醇多药耐药细胞系,测定耐药细胞系DNA聚合酶β（DNA polβ基因和蛋白表达。方法以紫杉醇为诱导药．人肺腺癌细胞系（A549）为诱导对象,逐步增加紫杉醇药物浓度进行诱导,建立耐紫杉醇的多药耐药细胞系A549／TXL20。采用MTT法检测A549／TXL20耐药指数,同时对顺铂、长春新碱、5氟脲嘧啶、丝裂霉素和羟基尿素五种药物进行交叉耐药检测。RC—PCR法和Western blotting法分别测定细胞内DNApolβ表达水平。结果A549／TXL20对紫杉醇及其他五种抗癌药物均有不同程度的耐药性。A549／TXL20细胞中DNA polβ mRNA及蛋白的表达水平均高于A549细胞（P〈0．05）。结论A549／TXL20具有多药耐药表型,耐药性产生可能与细胞内DNA polβ表达增高有关。     

人呼吸道合胞病毒转录调节基因转染肺腺癌细胞系的研究

目的获得稳定表达人呼吸道合胞病毒(hRSV)M2-1基因的人肺腺癌细胞系.方法通过基因重组法构建hRSV M2-1基因真核表达载体,用脂质体将其转染人肺腺癌PAa和A549细胞,经G418筛选获得阳性表达细胞株,并用逆转录-聚合酶链反应(RT-PCR)和Western Blot进行验证.结果得到了约650bp的基因插入片段,DNA测序表明该基因高度保守.筛选出了稳定高量表达M2-1基因的PAa和A549细胞,并被证实有M2-1蛋白表达.结论获得了稳定表达hRSV M2-1蛋白的PAa和A549细胞株.     

人肺腺癌细胞系A549线粒体差异蛋白质组学研究

目的 研究人肺腺癌细胞系A549与人正常支气管上皮细胞系16HBE线粒体蛋白质组的差异表达.方法 传代培养细胞系A549及16HBE,用线粒体提取试剂盒获取细胞线粒体蛋白质,进行双向凝胶电泳,运用液相色谱串联质谱分析技术筛选出A549和16HBE细胞系线粒体间表达水平显著差异的蛋白,所得结果通过Data Analysis软件标峰,用MASCOT进行结果搜索和数据分析.结果 双向电泳结果显示A549、16HBE细胞系线粒体存在差异的蛋白质点共41个,3倍以上差异的16个,A549细胞系中表达上调的15个,表达下调的26个,其中3倍以上差异表达上调的7个,表达下调的9个.运用液相色谱串联质谱技术鉴定出A549细胞系线粒体表达上调的蛋白质2个:AAA+ ATP酶家族结构域蛋白3B、tRNA鸟嘌呤糖基转移酶,表达下调的蛋白质7个:热休克蛋白75、复合物Ⅲ亚基1、复合物Ⅲ亚基2、鸟氨酸氨基转移酶、异柠檬酸脱氢酶亚基α、SLP-2、抗增殖蛋白.结论 应用亚细胞蛋白质组学方法,鉴定出肺腺癌细胞系线粒体差异表达蛋白,为阐明肺腺癌发生的分子机制、筛选早期诊断标志物提供了有益的线索.     

沉默Survivin人耐药肺癌细胞凋亡相关基因表达变化及临床意义

目的探讨沉默Survivin基因后人耐药肺腺癌(A549DDP)细胞系凋亡相关基因表达变化及临床意义。方法应用RT-PCR法及Western印迹法比较Survivin在人肺腺癌A549细胞系及其耐药A549DDP细胞系的表达水平;通过小分子RNA干扰沉默Survivin基因,并采用微阵列PCR基因芯片(PCR-Array)技术比较沉默Survivin后A549DDP细胞凋亡相关基因表达水平变化。结果 (1)Survivin mRNA、Survivin蛋白在人耐药非小细胞肺癌细胞系呈现高表达。(2)沉默Survivin后A549DDP细胞部分抗/促凋亡基因表达发生改变,促凋亡基因TP53、CASP3、CASP7呈高表达,抗凋亡基因bcl-2、TRAF1、BFAR呈低表达。结论 (1)Survivin与部分抗/促凋亡基因共同参与了非小细胞肺癌耐药的发生。(2)封闭Survivin可改变耐药肺癌细胞的促/抗凋亡基因的表达,Survivin可能作为上游调控点参与调控部分促/抗凋亡基因组的表达。(3)Survivin可能成为逆转肺癌耐药的一个新靶点。     

p53反义RNA对人肺癌细胞表型和顺铂敏感性的影响

目的：研究外源P53反义RNA对有P53基因248密码点突变的人肺癌细胞系恶性表型和顺铂敏感性的影响。方法：构建反义P53cDNA真核细胞表达载体,PEGFP－P53（AS）,经酶切图证明反向联结质粒,Lipofectin介质转染有P53基因248密码点突变的人肺癌细胞系801－D,经G418筛选获耐受克隆,稀释法建立单细胞克隆系,PCR检测外源基因,荧光显微镜检测细胞绿荧光蛋白表达,P53单抗免疫组化染色检测P53突变蛋白表达,体外集落形成,检测细胞恶性生长。流氏细胞仪检测细胞周期,MTTI地检测细胞对顺铂药物敏感性。结果：酶切图证明了P53－cDNA反向联结于质粒,构建了PEGFP－P53（AS）,建立了转染单细胞克隆系PEGFP－P53（AS）－801D及空载细胞系PEGFP－801D。PCR检测外源P53基因和neo基因存在于转染细胞PEGFP－P53（AS－801D。荧光显微镜下发现胞浆有绿荧光蛋白表达,免疫组化染色P53突变蛋白801D细胞系为阳性,而PEGFP－P53（AS）－801为阴性,证明外源反义P53封闭转染细胞内源突变蛋白表达。与母系相比PEGFP－P53（AS）－801D集落形成抑制率为61％（P＜0．01）,流氏细胞仪检测PEGFP－P53（AS）－801D细胞G1期细胞数明显增加,出现G1期阻止的表现,MTT检测PEGFP－P53（AS）－801D对顺铂比母系更为敏感。结论：有P53基因248密码点突变的801D细胞恶性增殖明显,对顺铂耐药,外源P53反义RNA可封闭突变蛋白表达,抑制801D细胞体外恶性增殖,增加对顺铂的药物敏感性,证明P53突变的恶笥表型可以被抑制或野生型P53功能可得到恢复。     

肺癌前病变、肺癌中FHIT基因表达的临床研究

背景与目的FHIT基因为近年发现的新候选抑癌基因，位于3P14．2跨越FRA3B易脆点，在包括肺癌在内的人类多种肿瘤中均存在异常表达。本研究旨在观察FHIT基因在人肺癌前病变、肺癌中表达情况，探讨FHIT基因在人肺癌发生、发展过程中的可能作用。方法采用免疫组化方法检测298例甲醛固定、石蜡包埋的标本（包括161例肺癌、51例肺癌前病变、30例正常肺组织、23例肺良性病变和33例肺癌转移淋巴结）中FHIT蛋白表达情况。结果FHIT蛋白在正常肺组织及肺良性病变组织中均无失表达；癌前病变组织及肺癌组织中失表达率分别为54．9％（28／51）和59．0％（95／161）：肺癌转移淋巴结组织中FHIT蛋白失表达率78．8％（26／33），各组问比较有显著性差异（P〈0．05）。肺癌组织中FHIT基因表达水平与肺癌组织学类型、肿瘤细胞分化程度、患者P-TNM分期、淋巴结转移程度存在相关性（P〈0．05）。FHIT蛋白失表达组肺癌患者的术后五年生存率显著低于表达组（P〈0．01）。吸烟组患者FHIT基因失表达率69．1％（94／136）显著高于无吸烟组49．5％（49／99）（P〈0．01）。结论FHIT蛋白失表达可能是肺癌发生过程中的早期分子事件，与肺癌的发生、发展及预后有关；吸烟导致FHIT蛋白表达下降可能是诱发肺癌的原因之一。     

肺癌中PI3K／AKT信号通路对Skp2调控机制的研究

目的探讨肺癌中磷脂酰肌醇-3-激酶（P13K）／AKT信号通路对S期激酶相关蛋白2（Skp2）的调控机制。方法体外培养4种类型肺癌细胞系H460、LK2、H446和A549,经LY294002处理细胞24h后实时RT—PCR法检测Skp2基因表达变化;Westernblot检测E2F1蛋白表达变化。结果实时RT—PCR显示LY294002作用后4种肺肿瘤细胞系中skp2基因表达均下降;Westernblot结果表明在小细胞肺癌、肺鳞癌、大细胞肺癌中E2F1蛋白表达降低,肺腺癌中E2F1蛋白未表达。结论肺癌中P13K／AKT通路可在转录水平调节Skp2表达,在小细胞肺癌、肺鳞癌、大细胞肺癌中此种调节可能通过转录因子E2F1发挥作用,而肺腺癌中E2F1不参与此种调节。     

Trop-2在肺腺癌组织和细胞系中的表达及临床病理分析

目的研究滋养层细胞表面抗原-2（Trop-2）在肺腺癌组织和细胞系中的表达及其临床病理意义。方法RT—PCR检测9例肺腺癌组织和20例癌旁组织中Trop-2mRNA的表达,免疫荧光检测人肺腺癌细胞系中Trop-2蛋白表达。分析Trop-2的表达同临床病理特征之间的相关性。结果在不同人肺腺癌细胞系中Trop-2表达的阳性率不同,于正常人支气管上皮细胞系中无表达。Trop-2mRNA在肺腺癌细胞系中有表达,Trop-2蛋白表达主要在肺腺癌细胞膜上;Trop-2在人肺腺癌组织中的阳性率显著高于癌旁组织;阳性表达程度随癌组织分化程度的降低而增高（P〈0．05）;Trop-2的表达同患者年龄、性别不相关（P〉0．05）。结论Trop-2在肺癌组织和肺癌细胞系中高表达,可作为检测人肺腺癌恶性程度的标记物。     

p53缺失和突变对人肺癌细胞系恶性表型影响的比较

目的 比较研究外源正义和反义p53对所转染细胞系恶性表型的影响。方法 构建正义和反义p53C—DNA真核细胞表达载体pEGFP—p53(RS)，pEGFP—p53(AS)，载体有绿荧光蛋白基因监测基因转染和表达。经酶切图证明p53正向或反向联结。Liipofectin介导转染801D细胞(801D细胞有p53缺失和突变，蛋白表达阳性)，G418筛选，建立单克隆细胞系。PCR检测外源p53和neo基因。荧光显微镜检查转染细胞绿荧光蛋白表达。免疫组化染色证明突变蛋白表达。比较了pEGFP—p53(AS)和pEGFP—p53(RS)集落形成试验，裸鼠移植试验。FCM分析细胞周期。结果 酶切图证明pEGFP—p53(RS)和pEGFP—p53(AS)的p53c—DNA(RS)分别正向和反向联结质粒pEGFP。Lipofectin介导转染细胞801D细胞，G418筛选，获耐受集落，建立单细胞克隆转染细胞系pEGFP—p53(RS)—801D，pEGFP—p53(AS)801D和pEGFP—801D。PCR检测外源p53和neo基因存在于细胞，细胞可见绿色荧光，证明外源基因存在并稳定表达。免疫组化检测pEGFP—p53(AS)—801D，突变蛋白呈阴性，母系为阳性，显示反义p53封闭突变蛋白表达。pEGFP—p53(RS)—801D和pEGFP—p53(AS)801D细胞集落形成率和裸鼠移植成瘤率均降低，pEGFP—p53(RS)-801D更低。FCM分析细胞周期延滞。结论 有p53缺失和突变的人肺癌细胞系801D体内外恶性增殖明显，在同一细胞背景下，p53缺失比p53突变对恶性增殖起更重要作用。外源野生型p53在肿瘤细胞中可重建抑癌功能，外源反义p53可封闭突变蛋白表达，阻止细胞停留于G1期。     

Restoration of fragile histidine triad (FHIT) expression induces apoptosis and suppresses tumorigenicity in lung and cervical cancer cell lines

Loss of expression of the Fhit protein is often associated with the development of many human epithelial cancers, including lung and cervical carcinomas. Restoration of Fhit expression in cell lines derived from these tumors has however yielded conflicting results, prompting the need for careful evaluation of the oncosuppressive potential of FHIT. In the present study, we have investigated the effect of Fhit reintroduction in seven lung cancer and three cervical cancer cell lines. To achieve efficient gene transfer and high levels of transgene expression, we have used an adenoviral vector to transduce the FHIT gene. The induction of apoptosis was evaluated by using the terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling assay and propidium iodide staining. Activation of caspases was detected by using Western blot analysis, and tumorigenic potential of transduced cells in the nude mouse was also assessed. Restoration of Fhit expression induced apoptosis in all Fhit-negative cell lines, with Calu-1, H460, and A549 being the most susceptible among the lung cancer cell lines and SiHa cells among cervical carcinomas. Activation of caspase-8 was always associated with Fhit-mediated apoptosis, and in vivo tumorigenicity was either abolished by FHIT gene transfer (in H460 and SK-Mes cells) or strongly suppressed (in A549 and SiHa cells). Our data demonstrate oncosuppressive properties and strong proapoptotic activity of the Fhit protein in lung and cervical cancer cell lines and strengthens the hypothesis of its possible use as a therapeutic tool.     

肺癌和癌前病变组织中FHIT、MSH2、p21蛋白表达及意义

目的探讨脆性组氨酸三联体（FHIT）、mutS同种组织蛋白2（MSH2）及p21蛋白表达在肺癌发生、发展中的意义。方法应用免疫组化SP法检测89份原发性肺癌组织（原发癌组）、12份淋巴结转移性肺癌组织（转移癌组）、12份肺癌癌前病变组织（癌前变组）及10份正常肺组织（对照组）中FHIT、MSH2及p21蛋白表达情况,分析各指标间相关性及其与肺癌临床病理参数的关系。结果与对照组比较,FHIT、MSH2及p21蛋白在其他三组中表达均下调（P〈0．05）;FHIT、MSH2蛋白表达与肺癌组织学类型、分化程度相关,p21蛋白表达与肺癌分化程度、临床分期及有无淋巴结转移有关（P均〈0．05）;FHIT和MSH2蛋白在原发癌组表达呈显著正相关（P〈0．01）,但均与p21蛋白表达无明显相关。结论FHIT、MSH2及p21蛋白与肺癌发生、发展有关,联合检测三项指标可为临床预测疾病进展提供依据。     

WWOX gene restoration prevents lung cancer growth in vitro and in vivo

The WWOX (WW domain containing oxidoreductase) gene at the common fragile site, FRA16D, is altered in many types of cancer, including lung cancer. We have examined the tumor suppressor function of WWOX in preclinical lung cancer models. The WWOX gene was expressed in lung cancer cell lines through recombinant adenovirus (Ad) infection (Ad-WWOX), and through a drug [ponasterone A, (ponA)]-inducible system. After WWOX restoration in vitro, endogenous Wwox protein-negative cell lines (A549, H460, and H1299) underwent apoptosis through activation of the intrinsic apoptotic caspase cascade in A549 and H460 cells. Ectopic expression of Wwox caused dramatic suppression of tumorigenicity of A549, H460, and H1299 cells in nude mice after Ad-WWOX infection and after ponA induction of Wwox expression in H1299 lung cancer cells. Tumorigenicity and in vitro growth of U2020 (Wwox-positive) lung cancer cells was unaffected by Wwox overexpression. This study confirms that WWOX is a tumor suppressor gene and is highly effective in preventing growth of lung cancer xenografts, whether introduced through viral infection or by induction of a silent WWOX transgene.     

Effect of FHIT gene replacement on growth,cell cycle and apoptosis in pancreatic cancer cells

The human FHIT gene is altered or lost in many cancers and FHIT has been shown to be a tumor suppressor. However, the mechanism of tumor suppression by the FHIT gene remains unclear. FHIT expression is lost in primary pancreatic cancer and human pancreatic cancer cell lines. To gain insight into the function of FHIT gene, we replaced the FHIT gene in a FHIT-null pancreatic cancer cell line, and established stable fhit-expressing clones. Expression of the exogenous fhit was at similar levels as in other cultured cell lines and fhit protein was found predominantly associated with perinuclear area. fhit replacement resulted in reduced cell proliferation in transfected Panc-1 cells. Cell cycle distribution analysis indicated increased accumulation of G0/G1 phase cells in transfected clones indicating a retardation of cell cycle progression. We observed specific up-regulation of cdc2 and cyclin D3 upon fhit replacement. Furthermore, Bcl-2 family members Bad, Bak, and Bcl-xS protein levels were increased in FHIT transfected clones when compared with Panc-1 cells. Multiplex RT-PCR of apoptosis pathway related genes revealed that Bcl-2 is absent and Bcl-xS message increases in FHIT transfected clones. Our data suggested that exogenous expression of FHIT in Panc-1 cells affects genes regulating cell cycle arrest and apoptosis, and these molecular changes may contribute to the tumor suppressor activity of the FHIT gene.     

miR-539通过靶向调控DCLK1抑制非小细胞肺癌的侵袭能力

目的 探讨非小细胞肺癌组织中miR-539的表达水平及其抑制肺癌细胞侵袭的作用机制.方法 通过基因表达数据库dbDEMC分析miR-539在非小细胞肺癌组织及正常肺组织中的表达量差异.根据235例miR-539高表达的非小细胞肺癌患者和102例miR-539低表达的非小细胞肺癌患者随访资料,分析miR-539与非小细胞...     

RON基因反义核酸真核表达载体的构建及其对A549的体外作用

目的肺癌的发生是多因素作用的结果,RON基因参与其中,但它在肺癌的基因治疗中意义尚不明确.本研究旨在探讨RON能否作为肺癌的基因治疗靶点及针对该基因跨膜区段(RONm)反义核酸对肺癌细胞的生物学功能的影响.方法从人肺鳞癌细胞提取总RNA进行RT-PCR、T载体克隆和测序,获得RON基因的跨膜区段,并将其反向插入真核表达载体中,转染肺癌细胞,利用ELISA检测细胞模型RON基因表达后的蛋白水平,同时利用MTT和细胞记数方法监测细胞的生物学活性的变化.结果用RT-PCR亚克隆RONm,测序结果与GenBank(X70040)一致.构建的RONm反义真核表达载体,转染后的肺癌细胞株A549 RON基因表达量和细胞活性明显降低.结论成功构建RONm反义核酸真核表达载体,RON能作为肺癌的基因治疗靶点;RONm反义核酸可有效抑制RON基因的表达阳性肺癌细胞的生长,为进一步研究将RONm反义核酸作为一种的肺癌基因治疗方法打下了分子生物学基础.     

Fragile histidine triad protein expression in nonsmall cell lung cancer and correlation with Ki-67 and with p53.

Fragile histidine triad (FHIT) is a tumour suppressor gene, which is altered in a variety of epithelial tumours, including lung cancer. Biochemical and functional pathways of its tumourigenicity are not yet understood. Its role in tumour proliferation is particularly controversial. The purpose of this study was to correlate the expression of FHIT protein in nonsmall cell lung cancer (NSCLC) with tumour proliferation as estimated by Ki-67 antigen and with p53, a suppressor gene. FHIT, Ki-67 and p53 expression were evaluated by immunohistochemistry in 119 resected NSCLC. Altogether, 58 tumours were negative (expression <10%) for FHIT. The median expression in tumours was 15% positive cells, in comparison with 100% in normal matched lung tissue. The expression was as strong as in normal tissue in only 19 cases. FHIT expression was significantly lower in squamous cell carcinoma (SCC) (5%) than in adenocarcinoma (ADC) (64%). The median expression of Ki-67 was 20% and 69% of tumours were positives (expression >10%). Ki-67 expression was significantly higher in SCC (33.3%) than in ADC (10%). The loss of FHIT protein was not correlated with the expression of p53 (median: 7.5%, 58% of positive tumours for a cut-off of 10% of positive cells) or Ki-67. But percentage of labelled cells for p53 and Ki-67 were significantly correlated. The results suggest that for fragile histidine triad, the pathway of tumourigenesis is independent of p53 and of tumoural proliferation, as reported previously in vitro.     

沉默HIF-1α调控MAPK/ERK信号通路抑制NSCLC转移的分析

目的探讨HIF-1α在体内及体外对非小细胞肺癌(NSCLC)细胞转移的影响及其作用机制。 方法采用实时荧光定量PCR(RT-qPCR)检测HIF-1α在癌旁正常组织、肺鳞癌组织(LUSC)、肺腺癌组织(LUAD)、A549细胞和HEB细胞中的表达量。上调HIF-1α表达后,通过MTT、细胞侵袭和Western blot实验检测过表达HIF-1α对A549细胞增殖、侵袭和EMT的影响。下调HIF-1α表达后,Western blot检测A549细胞ERK和p-ERK蛋白的表达量。THBQ激活MAPK/ERK通路后,分析A549细胞增殖、侵袭和EMT能力。将细胞株植入裸鼠体内,构建移植瘤模型,最后测量裸鼠移植瘤的体积和重量。 结果HIF-1α在NSCLC组织的表达水平明显高于癌旁正常组织(P<0.05)。A549细胞中HIF-1α表达水平明显高于HEB细胞(P<0.01),过能够促进A549细胞的增殖和侵袭,N-cadherin蛋白表达量明显上升,E-cadherin蛋白表达量明显下降。下调HIF-1α能够抑制A549细胞内MAPK/ERK通路,且抑制了A549细胞的增殖、侵袭和EMT。下调HIF-1α使裸鼠移植瘤的重量和体积明显减小。 结论沉默HIF-1α通过MAPK/ERK信号通路在体内及体外抑制NSCLC转移。     

Overexpression of cyclooxygenase-2 in non-small cell lung cancer

Evidence is accumulating to suggest that the inducible isoenzyme of cyclooxygenase (COX)-2 is up-regulated in human cancers and epidemiological studies indicate that COX inhibitors may have a protective effect on the development of lung cancer. We used immunohistochemistry and Western blotting to investigate COX expression in lung tumour specimens and three lung cancer cell lines. Sixty-five archival lung tissue samples, including 46 squamous cell and 6 adenocarcinoma lung resections, and 13 small cell lung cancer (SCLC) biopsies were studied. Dense and intense cytoplasmic COX-2 staining was found in all 52 resections from non-small cell lung cancer (NSCLC). The staining was diffuse and much stronger than adjacent respiratory epithelium. COX-2 staining was relatively weak in the majority of the SCLC samples. The bronchial and bronchiolar epithelium in the surrounding normal lung structures showed uniform COX immunoreactivity with apical concentration of the stain. There was no increase in COX-1 staining in any tumour type. Western blot analysis of the cancer lines revealed significantly higher expression of COX-1 in CORL23 line and COX-2 in two NSCLC cell lines (MOR/P; A549) compared with the expression of COX-1 and COX-2 in cultured normal bronchial epithelial cells. Our findings demonstrated COX-2 overexpression in NSCLC.