抗EGFR单抗联合EGFR酪氨酸激酶抑制剂对人肺腺癌细胞凋亡的影响及其机制

目的:目前抗表皮生长因子受体(epidermal growth factor receptor, EGFR)的小分子酪氨酸激酶抑制剂吉非替尼(gefitinib)和抗EGFR单克隆抗体西妥昔单抗(cetuximab)在肺癌的临床应用中颇为广泛.鉴于这两种药物均针对EGFR分子靶点,因此本研究旨在就上述两种药物联合用药对人肺腺癌细胞凋亡的影响及其分子机制进行探讨.方法:吉非替尼和西妥昔单抗单独或联合用药作用于人肺腺癌细胞株A549和SPC-A-1后,用碘化丙啶标记,采用流式细胞术观察细胞凋亡情况,活细胞计数试剂盒测定各组细胞增殖抑制情况,Western印迹法检测两种药物对EGFR下游信号通路蛋白[磷酸化蛋白激酶B(phosphorylated Akt, p-Akt)、磷酸化EGFR(phosphorylated EGFR,p-EGFR)和磷酸化丝裂原激活蛋白激酶(phosphorylated mitogen-activated protein kinase, p-MAPK)]在蛋白水平表达的影响.结果:吉非替尼或西妥昔单抗单独作用后,A549和SPC-A-1细胞均明显凋亡,同时细胞增殖受到不同程度的抑制.Western印迹法检测p-Akt、p-EGFR和p-MAPK蛋白表达量均较不用药对照组下降.吉非替尼和西妥昔单抗联合作用后,肺腺癌细胞的凋亡、增殖以及在EGFR分子层次表现出较单一用药更为显著的作用.结论:吉非替尼和西妥昔单抗两种药物之间具有良好的协同作用,联合用药可能在临床治疗非小细胞肺癌中具有较大的应用潜力.     

洛伐他汀克服非小细胞肺癌PC9细胞株吉非替尼耐药的体外研究

目的:研究联合洛伐他汀(lovastatin)和吉非替尼(gefi tinib)对体外诱导吉非替尼获得性耐药的非小细胞肺癌细胞株PC9细胞凋亡以及相关蛋白表达的影响,并探讨其可能的机制。方法:应用洛伐他汀联合吉非替尼处理耐吉非替尼的非小细胞肺癌PC9细胞株后,采用WST-1法检测不同药物处理对PC9细胞增殖的影响,Hoechst33342荧光染色法观察细胞凋亡形态,FCM法观察细胞凋亡状况,蛋白质印迹法检测凋亡相关蛋白的表达水平。结果:洛伐他汀联合吉非替尼可在体外诱导耐吉非替尼的PC9细胞凋亡,抑制其细胞增殖;洛伐他汀联合吉非替尼可诱导耐吉非替尼的PC9细胞中磷酸化表皮生长因子受体(phosphorylated epidermal growth factor receptor,p-EGFR)、磷酸化蛋白激酶B(phosphorylated protein kinase B,p-AKT)和磷酸化细胞外调节蛋白激酶1/2(phosphorylated extracellular signal-regulated kinase1/2,p-ERK1/2)蛋白表达水平明显下调。结论:在体外诱导吉非替尼获得性耐药的非小细胞肺癌细胞株PC9中,洛伐他汀可以克服吉非替尼耐药,两者具有良好的协同作用,提示两药联合对于出现吉非替尼耐药的非小细胞肺癌的临床治疗可能具有很大的应用潜力。     

吉非替尼与紫杉醇联合对卵巢癌细胞凋亡影响的观察

目的:探讨吉非替尼联合紫杉醇诱导人卵巢癌细胞凋亡的影响。方法:吉非替尼单独或联合紫杉醇作用卵巢癌HO8910细胞,以蛋白质印迹法检测EGFR下游信号磷酸化Akt(p-Akt)、磷酸化细胞外信号调节激酶(p-ERK)和细胞核增殖抗原(PCNA),以MTT法检测细胞增殖率,FCM法检测细胞周期分布和凋亡。结果:吉非替尼单用在0.25～4.00μmol/L浓度范围内呈浓度依赖性抑制卵巢癌HO8910细胞增殖,1.0μmol/L浓度单独作用24h则细胞周期主要分布于G1期,p-Akt、p-ERK和PCNA蛋白水平下降,72h时细胞凋亡增加,与对照组比较,差异均有统计学意义,P<0.05。吉非替尼与紫杉醇合用不仅能更显著的抑制细胞增殖,而且凋亡细胞显著增加(P<0.05),与对应浓度单用紫杉醇比较,差异均有统计学意义,P<0.05。结论:吉非替尼与紫杉醇合用能显著抑制卵巢癌HO8910细胞增殖、诱导凋亡,两种药物合用具有协同作用。     

EGFR/IGFR-1β异二聚体形成对吉非替尼抑制结肠癌细胞增殖的影响

目的:观察EGFR(epidermal growth factor receptor)和IGFR-1β(insulin-like growth factor receptor-1β)的相互作用,探讨IGFR-1β对吉非替尼(gefitinib)抑制结肠癌细胞增殖的影响。方法:以免疫共沉淀法和Western blotting检测EGFR和IGFR-1β之间以及受体与下游信号通路蛋白AKT、MAPK的结合。以IGFR-1酪氨酸激酶抑制剂AG1024和吉非替尼单独或联合作用于3种结肠癌细胞(LoVo,HT29,HCT116细胞),MTT法检测细胞增殖率。结果:LoVo细胞(吉非替尼敏感型)在有或无吉非替尼作用下均不出现与EGFR结合的IGFR-1β条带,HT29细胞(吉非替尼中度敏感型)在吉非替尼作用下可见该条带,而HCT116细胞(吉非替尼耐受型)在有或无吉非替尼作用下均可见条带。LoVo细胞的吉非替尼作用组、HT29细胞的联合用药组以及HCT116细胞的AG1024作用组EGFR结合的AKT、MAPK显著减少(P<0.05)。LoVo细胞在吉非替尼组的细胞增殖率较对照组明显下降(P<0.05),AG1024单独组的增殖率无明显降低,联合用药组与吉非替尼单独组相比较并未进一步降低;HT29细胞在单独应用吉非替尼或AG1024时增殖率均无明显降低,联合用药组的增殖率显著下降(P<0.05);HCT116细胞在吉非替尼作用下增殖率无明显降低,但在AG1024作用下增殖率显著降低(P<0.05),联合用药组与AG1024单独作用组相比较并未进一步降低。结论:结肠癌细胞耐受吉非替尼作用可能或者部分可能与EGFR/IGFR-1β异二聚体形成激活IGFR-1β信号通路有关,抑制IGFR-1β活性在一定程度上可以提高结肠癌细胞对吉非替尼的敏感性。     

大黄素逆转非小细胞肺癌EGFR-TKI耐药的机制研究

目的 探讨大黄素逆转非小细胞肺癌（NSCLC）表皮生长因子受体酪氨酸激酶抑制剂（EGFR TKI）耐药的作用机制。方法 应用持续诱导的方法构建NSCLC EGFR-TKI耐药细胞株HCC827／GR;应用MTS法检测大黄素（30μmol／L）、吉非替尼（1μmol／L）及两药联合处理HCC827和HCC827／GR细胞48h后细胞增殖能力的变化;应用Western blotting法检测HCC827和 HCC827／GR细胞中p EGFR、p-AKT、p-ERK1／2及p-MET蛋白表达水平的变化。结果 MTS法检测结果显示,经单药吉非替尼或大黄素处理后,HCC827／GR细胞增殖能力未减弱,而两药联合处理组的细胞增殖能力明显下降,差异有统计学意义（P＜0.05）。Western blotting检测结果显示,HCC827、HCC827／GR细胞中p-EGFR、p-ERK1/2明显表达,而p-AKT表达微弱;HCC827／GR 中p-MET表达水平较HCC827明显上调。经单药吉非替尼处理后,HCC827细胞株p-EGFR、p-ERK1/2表达水平下调,HCC827／GR细胞株p-EGFR表达明显下调;大黄素可显著下调HCC827／GR细胞株p-MET表达,但对p-EGFR、p-ERK1/2的表达无影响;而大黄素与吉非替尼两药联用可明显抑制HCC827／GR细胞株p-EGFR、p-ERK1/2以及p-MET的表达。结论 大黄素可以逆转NSCLC EGFR-TKI耐药,可能是通过抑制c-Met的活化来实现。     

EGFR-TKI联合COX-2抑制剂抑制肺腺癌A549细胞的增殖及其机制

目的:研究表皮生长因子受体酪氨酸激酶抑制剂(epidermal growth factor receptor tyrosine kinase inhibitor,EGFR-TKI)吉非替尼联合环氧合酶-2(cyclooxygenase-2,COX-2)抑制剂塞来昔布对肺腺癌A549细胞增殖的抑制作用及其可能机制。方法:实验设空白对照组、吉非替尼组、塞来昔布组、吉非替尼+塞来昔布组。倒置相差显微镜下观察A549细胞形态变化,MTT法检测A549细胞增殖,流式细胞术检测A549细胞周期及凋亡,Western blotting检测A549细胞中EGFR、p-EGFR、COX-2的表达。结果:吉非替尼和塞来昔布均可抑制A549细胞的增殖,可见细胞活性下降,G1期细胞阻滞及细胞凋亡增加;联合用药较单药组A549细胞活性下降更明显,G1期阻滞细胞增加,且细胞凋亡增加。吉非替尼或塞来昔布作用前后A549细胞EGFR表达无变化,但联合用药组p-EGFR及COX-2的表达较单药组显著下降。结论:吉非替尼联合塞来昔布可抑制人肺腺癌A549细胞的增殖,其机制可能与抑制EGFR的活化及下调COX-2的表达有关。     

c-Met信号通道参与HGF诱导不同基因型非小细胞肺癌细胞株对吉非替尼耐药

背景与目的肝细胞生长因子(hepatocyte growth factor,HGF)诱导非小细胞肺癌(non-small cell lung cancer,NSCLC)对吉非替尼耐药,可能与其受体c-Met激活有关。本研究旨在探讨c-Met及其下游信号通道是否参与HGF诱导不同基因型NSCLC细胞株对吉非替尼耐药。方法选择人NSCLC细胞株表皮生长因子受体(epidermal growth factor receptor,EGFR)突变型PC-9、PC9/R和EGFR野生型H292、A549,用HGF诱导细胞,通过MTT法检测细胞增殖,Annexin V-FITC法检测细胞凋亡,应用免疫印迹技术检测细胞中c-Met及下游通道的变化。结果吉非替尼对PC9、H292、A549的生长抑制作用呈浓度依赖性,HGF诱导后吉非替尼抑制细胞的生长曲线明显往右移。在PC9、H292、A549细胞中,吉非替尼和HGF处理组的细胞凋亡率比吉非替尼处理组均减少(P<0.05),在PC9/R细胞中无明显减少(P>0.05)。HGF能激活PC9、H292、PC9/R、A549细胞中c-Met及其下游通道蛋白。在PC9、H292、A549细胞中,吉非替尼和HGF处理组的p-Met、p-Akt、p-Stat3、p-Erk1/2蛋白表达比吉非替尼处理组均增高,在PC9/R细胞中无明显增高。结论在体外HGF诱导不同基因型NSCLC细胞株对吉非替尼耐药,c-Met及其下游信号通道参与HGF诱导不同基因型NSCLC细胞株对吉非替尼耐药。     

IGF-1R抑制剂AG1024对头颈鳞癌FaDu细胞放射敏感性的影响

背景与目的:胰岛素样生长因子1受体(insulin-like growth factor 1 receptor,IGF-1R)在多数头颈鳞癌中高表达。本研究拟探讨IGF-1R抑制剂AG1024对头颈鳞癌FaDu细胞的放射增敏作用。以此探索IGF-1R联合放射治疗头颈鳞癌的疗效及可能机理,为临床寻找有效的以IGF-1R为靶点的肿瘤治疗方法提供实验依据。方法:以头颈鳞癌FaDu细胞为研究对象,克隆形成实验分析细胞放射敏感性,应用流式细胞术(flow cytometry,FCM)检测AG1024对FaDu细胞早期凋亡及周期的影响。进一步应用γ-H2AX形成实验检测DNA双键断裂(double-strand breaks,DSBs)的修复情况;蛋白质印迹法(Western blot)及免疫沉淀法测定IGF-1R下游蛋白激酶B(protein B,Akt)和细胞外调节蛋白激酶1/2(extracellular regulated protein kinases1/2,Erk1/2)的活化水平,动物实验观察对肿瘤生长的影响。结果:AG1024联合放疗使细胞存活曲线的肩区明显变窄,反映放射敏感性指标的D0降低;FCM检测结果表明,AG1024联合放疗可增加FaDu细胞的早期凋亡水平(P<0.05),使细胞的G0/G1期比例增高(P<0.05),S期比例降低(P<0.05);在放射后24 h进一步的γ-H2AX形成实验显示,Ag1024能抑制DSBs的修复(P<0.05);同时,经AGl024处理后,细胞中磷酸化Akt(p-Akt)和磷酸化Erk1/2(p-Erk1/2)的表达水平明显降低;动物实验的结果显示药物联合照射能明显抑制肿瘤的生长。结论:IGF-1R抑制剂AG1024在体内和体外对头颈鳞癌FaDu细胞均有放射增敏作用,其机制可能与改变细胞周期并诱导细胞凋亡、抑制DSBs的修复、下调P13K/Akt及Ras/Raf/MAPK信号通路有关。     

抑制EGFR、IGFR-1β活性对结肠癌细胞周期和凋亡的影响

目的:采用EGFR酪氨酸激酶抑制剂吉非替尼与IGFR-1酪氨酸激酶抑制剂AG1024单独或联合作用于结肠癌细胞,探讨抑制EGFR、IGFR-1β活性对细胞周期和凋亡的影响.方法:以流式细胞术检测结肠癌细胞的细胞周期和凋亡,以AnnexinⅤ-FITC/PI双标检测细胞凋亡率.结果:与对照组比较,Lovo细胞G1期阻滞在吉非替尼组和联合用药组较显著(P＜0.05),而二者之间差异不明显(P＞0.05);AG1024组与对照组比较无差异(P＞0.05).HT29细胞G1期阻滞在联合用药组较显著(P＜0.05),吉非替尼组和AG1024组均不显著(P＞0.05).HCT116细胞G1期阻滞在AG1024组和联合用药组较显著(P＜0.05),而二者之间差异不明显(P＞0.05);吉非替尼组与对照组比较无差异(P＞0.05).Lovo细胞凋亡率增加在吉非替尼组和联合用药组较显著(P＜0.05),而二者之间差异不明显(P＞0.05);AG1024组的凋亡率无明显增加.HT29细胞凋亡率增加在联合用药组较显著(P＜0.05),吉非替尼组和AG1024组均不明显.HCT116细胞凋亡率增加在AG1024组和联合用药组较显著(P＜0.05),而二者之间差异不明显(P＞0.05);吉非替尼组的凋亡率无明显增加.结论:抑制Lovo细胞的EGFR活性以及抑制HCT116细胞的IGFR-1β活性可分别引起细胞G1期阻滞及诱导凋亡增加,在HT29细胞中产生这种抑制效应则需要同时抑制EGFR、IGFR-1β的活性.     

吉非替尼联合AG1024抑制结肠癌细胞生长的体外研究

目的:探讨抑制表皮生长因子受体(EGFR)、胰岛素样生长因子1型受体(IGFR-1)活性对不同结肠癌细胞下游信号通路的影响及其产生的细胞生长抑制效应.方法:选择对EGFR抑制剂吉非替尼敏感性不同的结肠癌细胞,给予IGFR-1酪氨酸激酶抑制荆AGl024和吉非替尼单独或联合作用,以蛋白质印迹法检测EGFR、IGFR-1β及其下游信号蛋白AKT、MAPK表达和活性,以MTT法检测细胞增殖率.结果:LOVO细胞(吉非替尼敏感型)在吉非替尼作用下AKT、MAPK活性被抑制,P＜0.05,而不论是否与AG1024联合;HT29细胞(吉非替尼中度敏感型)在吉非替尼和AG1024单独作用下AKT、MAPK活性均抑制不明显,而联合作用则其活性显著被抑制,P＜0.05;HCT116细胞在AG1024作用下AKT、MAPK活性被抑制,P＜0.05,而不论是否与吉非替尼联合.细胞增殖率显著降低见于吉非替尼作用下的LOVO细胞、吉非替尼联合AG1024作用下的HT29细胞以及AG1024作用下的HCT116细胞(P＜0.05).结论:吉非替尼联合AG1024可阻断下游信号通路的持续活化,在一定程度上可以改善结肠癌细胞对吉非替尼生长抑制作用的耐受.     

Biomarkers in clear cell renal cell carcinoma

The treatment of advanced renal cell carcinoma (RCC) has evolved significantly following the identification of the von Hippel–Lindau (VHL) gene and the function of its protein, and subsequent development of antiangiogenic therapies. A series of clinical trials resulted in the approval of three new agents with significant activity in this disease. Additional studies are now underway to identify subsets of patients most likely to benefit. This article reviews the current therapy for advanced RCC and the development of biomarkers in RCC. This requires the identification of disease characteristics at a clinical, genetic and molecular level associated with response and/or surrogate measures of clinical benefit. Currently, a variety of prognostic factors (lactate dehydrogenase, performance status, disease-free interval, hemoglobin and calcium levels) are utilized to predict the survival of RCC patients. The use of validated biomarkers in either serum/plasma, urine or tissue could enhance this process, as well as define at the molecular and genetic levels, factors associated with response to therapy and/or the development of resistance. Examples include plasma VEGF levels, VHL gene mutation status and carbonic anhydrase IX levels in tumor tissue, among others. Validation of such biomarkers is crucial in order for them to be clinically useful.     

Biomarkers in clear cell renal cell carcinoma

The treatment of advanced renal cell carcinoma (RCC) has evolved significantly following the identification of the von Hippel-Lindau (VHL) gene and the function of its protein, and subsequent development of antiangiogenic therapies. A series of clinical trials resulted in the approval of three new agents with significant activity in this disease. Additional studies are now underway to identify subsets of patients most likely to benefit. This article reviews the current therapy for advanced RCC and the development of biomarkers in RCC. This requires the identification of disease characteristics at a clinical, genetic and molecular level associated with response and/or surrogate measures of clinical benefit. Currently, a variety of prognostic factors (lactate dehydrogenase, performance status, disease-free interval, hemoglobin and calcium levels) are utilized to predict the survival of RCC patients. The use of validated biomarkers in either serum/plasma, urine or tissue could enhance this process, as well as define at the molecular and genetic levels, factors associated with response to therapy and/or the development of resistance. Examples include plasma VEGF levels, VHL gene mutation status and carbonic anhydrase IX levels in tumor tissue, among others. Validation of such biomarkers is crucial in order for them to be clinically useful.     

Non-small and small cell lung carcinoma cell lines exhibit cell type-specific sensitivity to edelfosine-induced cell death and different cell line-specific responses to edelfosine treatment

The unique signal transduction pathways that distinguish non-small cell lung carcinoma (NSCLC) from small cell lung carcinoma (SCLC) are poorly understood. We investigated the ability of edelfosine, an inhibitor of phosphatidylinositol-specific phospholipase C (PLC) to inhibit cell viability among four NSCLC cell lines and four SCLC cell lines. The differential sensitivity of cells to edelfosine's cytostatic and cytotoxic effects has been attributed to edelfosine-induced changes in the activities of many enzymes, including c-Jun NH2-terminal kinase (JNK), extracellular signal-regulated kinases (ERK), p38 kinase, and poly(ADP-ribose) polymerase (PARP). To investigate the role of these enzymes in edelfosine-induced cytotoxicity, we correlated edelfosine-induced changes in enzyme activity and cell viability among the different NSCLC and SCLC cell lines. We found that NSCLC cells are much more susceptible to the cytotoxic effects of this drug than are SCLC cells. Three out of the four edelfosine-sensitive NSCLC cell lines (NCI-H157, NCI-H520, NCI-H522) exhibit G2/M arrest, significant apoptosis and some degree of JNK activation in response to drug treatment. In contrast, none of the SCLC cell lines exhibit edelfosine-induced G2/M arrest or significant apoptosis. A comparison of the edelfosine-induced effects among the sensitive and resistant lung cancer lines indicates that there is little correlation between edelfosine-induced cytotoxicity and altered activities of JNK, ERK, p38, or cleavage of PARP. These results demonstrate that edelfosine-induced changes in JNK, ERK, p38, or PARP are not good predictors of cell susceptibility to edelfosine-induced cytotoxicity. Thus, edelfosine-induced inactivation of PLC may disrupt signaling cascades downstream of PLC that are unique to individual cellular environments. These findings also identify edelfosine as one of the few potential chemotherapeutic agents that has a greater cytotoxic effect against NSCLC cells than SCLC cells.     

桥接整合因子1通过AKT-mTOR通路诱导非小细胞肺癌H1975细胞周期阻滞

目的：研究桥接整合因子1（bridging intergrator 1,Bin1）基因过表达后对非小细胞肺癌细胞株H1975细胞周期的影响及其作用机制。方法：构建携带Bin1基因的CMV-MCS-GFP-SV40-Neomycin-Bin1质粒,并转染H1975细胞（Bin1+组）,另设置空白质粒转染组（Bin1-组）及空白对照组（Ctrl组）,利用RT-PCR和Western blotting分别检测3组细胞中Bin1在mRNA和蛋白质水平的表达情况。流式细胞术检测不同处理组H1975细胞周期的变化,Western boltting分别检测各组中AKT、mTOR磷酸化水平及细胞周期相关蛋白（周期蛋白D1、CDK4、Rb）的表达情况。结果：与Bin1-组、Ctrl组比较,Bin1+组H1975细胞中Bin1在mRNA、蛋白水平表达明显上调（均P<0.05）; H1975细胞阻滞在G1期\[（60.53±1.89）% vs（46.14±1.56）%、（47.33±2.07）%,均P<0.05\]; Bin1+组H1975细胞内p-AKT、p-mTOR表达下调（均P<0.05）,AKT、mTOR表达变化无统计学差异（P>0.05）;周期蛋白D1、CDK4的表达量均明显下调(P<0.05),Rb表达量明显增加（P<0.05）。结论：Bin1基因在H1975细胞株过表达后明显诱导细胞周期阻滞,其机制可能是通过抑制AKT-mTOR通路及其细胞周期相关蛋白实现的。     

A human squamous cell carcinoma cell line.

An epithelial cell line COLO 16 has been established from a human squamous carcinoma, characterized and maintained for over two years. The cells produce a parathyroid-like hormone and carcinoembryonic antigen. The line is definitely not a "HeLa contaminant." The cell line is available to other investigators.