双氢青蒿素和顺铂诱导人肺腺癌A549/CDDP 细胞凋亡

目的:观察双氢青蒿素和顺铂在体外对A549/CDDP细胞的作用,分析双氢青蒿素逆转耐药效果,从诱导细胞凋亡角度分析可能的作用机理。方法:A549/CDDP细胞分为双氢青蒿素作用组和顺铂对照组,顺铂对细胞增殖抑制实验采用MTT检测法,用annexin-V和PI双标记进行流式细胞检测分析细胞凋亡率。双氢青蒿素对细胞Bcl-2,Bax等蛋白的影响采用免疫组织化学法结合图像分析。结果:对人肺腺癌A549/CDDP细胞双氢青蒿素作用组和顺铂对照组IC50值分别为1.30μg/ml和5.58μg/ml,两组比较差异显著(P<0.01),逆转倍数4.29。对A549/CDDP细胞,双氢青蒿素作用组和对照组凋亡率分别为17.6%和1.6%两组比较差异显著(P<0.01)。双氢青蒿素作用于A549/CDDP细胞后,Bcl-2蛋白表达下降,Bax蛋白表达上升。结论:A549/CDDP细胞耐药作用与凋亡耐受有关,双氢青蒿素可使A549/CDDP细胞恢复对顺铂的敏感性,通过解除凋亡抑制从而逆转耐药。     

双氢青蒿素和顺铂诱导人肺腺癌A549/CDDP细胞凋亡

目的：观察双氢青蒿素和顺铂在体外对A549/CDDP细胞的作用,分析双氢青蒿素逆转耐药效果,从诱导细胞凋亡角度分析可能的作用机理。方法：A549/CDDP细胞分为双氢青蒿素作用组和顺铂对照组,顺铂对细胞增殖抑制实验采用MTT检测法,用annexin-V和PI双标记进行流式细胞检测分析细胞凋亡率。双氢青蒿素对细胞Bcl-2,Bax等蛋白的影响采用免疫组织化学法结合图像分析。结果：对人肺腺癌A549/CDDP细胞双氢青蒿素作用组和顺铂对照组IC50值分别为1.30μg/ml和5.58μg/ml,两组比较差异显著（P〈0.01）,逆转倍数4.29。对A549/CDDP细胞,双氢青蒿素作用组和对照组凋亡率分别为17.6%和1.6%两组比较差异显著（P〈0.01）。双氢青蒿素作用于A549/CDDP细胞后,Bcl-2蛋白表达下降,Bax蛋白表达上升。结论：A549/CDDP细胞耐药作用与凋亡耐受有关,双氢青蒿素可使A549/CDDP细胞恢复对顺铂的敏感性,通过解除凋亡抑制从而逆转耐药。     

重组人肿瘤坏死因子相关凋亡诱导配体蛋白(rhTRAIL) 逆转人肺腺癌细胞A549/ CDDP耐顺铂效应的初步研究

 目的 探讨重组人可溶性肿瘤坏死因子相关诱导配体蛋白(rhTRAIL)对人肺腺癌细胞A549／CDDP耐顺铂的逆转效应。方法 以顺铂(CDDP)联合不同浓度的rhTRAIL处理A549／CDDP，以四氮唑噻蓝盐(MTT)比色法检测顺铂的半效抑制浓度IC50并计算耐药逆转倍数RI。结果 rhTRAIL体外可明显降低A549／CDDP对CDDP的IC50提高耐药逆转倍数。结论 rhTRAIL体外可较大程度逆转A549／CDDP细胞对CDDP的耐药性，有望成为抗耐药性肺癌的一种新的生物制剂。     

重组人血管内皮抑素逆转人肺腺癌A549/DDP细胞耐药性研究

目的探讨重组人血管内皮抑素(rh-ES)对A549/DDP细胞耐药性的逆转作用.方法采用人肺腺癌细胞株A549及耐药细胞株A549/DDP作为研究对象,以顺铂(DDP)与重组人血管内皮抑素两者联合及单独给药的方式分别作用于人肺腺癌细胞株A549及耐药细胞株A549/DDP,作用时间72 h,观察不同给药方式造成的同株细胞之间耐药性的不同及不同株细胞间耐药性的差别,采用四甲基偶氮唑蓝(MTT)法检测重组人血管内皮抑素对A549/DDP细胞耐药性的逆转作用.结果DDP对A549细胞半数抑制浓度(IC50)为(0.72±0.05)μg/ml,对A549/DDP的IC50为(11.54±0.64)μg/ml.rh-ES联合DDP对A549/DDP的IC50为(2.0±0.1)μg/ml.逆转倍数(RF)为5.77,相对逆转率(RRR)为88.2%.结论重组人血管内皮抑素能逆转A549/DDP对DDP的耐药性.     

榄香烯乳剂对肺癌A549/DDP细胞株耐药逆转作用及其机制

目的:探讨榄香烯乳（elemene,ELE）逆转人肺腺癌A549/DDP细胞株耐药性及其机制。方法:采用MTT法检测榄香烯乳单用的细胞毒作用及与顺铂（cisplatin,DDP）合用时耐药逆转作用;采用流式细胞术检测榄香烯乳对A549/DDP细胞内罗丹明-123（rhodamine-123,Rh123）蓄积的影响;采用Western blot检测榄香烯乳对耐药细胞A549/DDP细胞膜上P-gp蛋白表达的影响。结果:不同浓度榄香烯对A549/DDP细胞均有一定的抑制作用,呈时间-剂量依赖性效应。单用DDP的IC50为15.46μg/ml,合用20μg/ml榄香烯24h,IC50为4.15μg/ml,逆转耐药倍数为3.63。同时,榄香烯增加A549/DDP细胞内Rh123的蓄集,降低细胞膜上P-gp的表达,且呈剂量依赖性,表明榄香烯能减少A549/DDP细胞对药物的外排和抑制P-gp蛋白的表达。结论:榄香烯在体外逆转肿瘤细胞耐药性可能与其抑制P-gp的功能和表达有关。     

靶向ERCC1 RNA干扰对人肺腺癌细胞顺铂耐药的逆转

目的:探讨利用RNA干扰技术切除修复交叉互补基因1(excision repair cross-completion gene 1,ERCC1)逆转耐顺铂(cisplatin,CDDP)人肺腺癌细胞A549/CDDP的耐药性。方法:(1)常规体外培养A549/CDDP细胞,以脂质体包裹的ERCC1-siRNA转染细胞,转染浓度分别为100、200、300 nmol/L,并设空白转染、Lip转染对照组,观察转染效果。(2)采用免疫组化SABC法及RT-PCR法分别检测肿瘤细胞转染siRNA后ERCC1基因和蛋白的表达。(3)MTT法检测肿瘤细胞耐药指数,观察ERCC1靶向siRNA逆转A549/CDDP细胞顺铂耐药的效果。结果:(1)Lip组、siRNA-neg组转染效率分别为(56.38±9.82)%、(63.54±4.87)%,SiRNA-ERCC1①组、siRNA-ERCC1②组、siRNA-ERCC1③组转染效率分别为(43.62±6.08)%、(65.85±9.61)%和(78.93±4.86)%。(2)针对ERCC1的siRNA转染A549/CDDP后,细胞ERCC1 mRNA及蛋白表达均下调,siRNA-ERCC1(300 nmol/L)组效应最强,分别下降至(11.19±6.82)%和(20.88±6.57)%(P<0.01)。(3)A549/CDDP细胞转染后耐药倍数减为6.05、4.64、2.94,空载体对照组细胞的耐药倍数为9.6。结论:RNA干扰技术封闭ERCC1基因可较大程度逆转耐顺铂人肺腺癌细胞的耐药性,且呈一定的浓度依赖性;ERCC1基因可作为逆转肺癌耐药治疗的有效靶点。     

热疗联合а-IFN逆转人肺腺癌细胞A549/CDDP耐药性的研究

目的探讨热疗联合α-IFN对人肺腺癌细胞A549/CDDP耐药逆转作用及可能机制。方法采用体外细胞培养技术,培养人肺腺癌细胞系A549及其耐药株A549/CDDP。设计1μg/ml、2μg/ml、4μg/ml浓度的CDDP,分别联合100U/ml、500U/ml、1000U/ml浓度а-IFN,在42℃热疗干预2h后,采用MTT法检测2种细胞对化疗药物CDDP的敏感性,采用流式细胞仪间接免疫荧光法,检测α-IFN、CDDP、热疗处理前后细胞中P-糖蛋白（P-gp）的表达及细胞内荧光药物CDDP的聚集量。结果热疗、а-IFN分别联用CDDP时,对A549/CDDP细胞的抑制率较单用CDDP时的抑制率高,差异有统计学意义（P〈0.05）。热疗联合а-IFN与CDDP时,对A549/CDDP细胞的抑制率较热疗、а-IFN分别联用CDDP时明显升高（P〈0.05）。热疗、а-IFN分别联合CDDP时,A549/CDDP细胞P-gp表达率较单用CDDP时下降,细胞内荧光强度增强,热疗联合α-IFN与CDDP,CDDP/A549P-gp表达率明显下降,细胞内荧光强度显著增强。结论а-IFN、热疗能部分逆转人肺腺癌细胞系A549/CDDP的耐药性;а-IFN联合热疗可提高逆转肺癌细胞耐药效应,其机制可能与抑制P-gp表达,增加细胞内化疗药物的积聚有关。     

榄香烯联合高温和顺铂对人肺腺癌A549细胞的杀伤作用

目的观察榄香烯联合高温和顺铂对人肺腺癌A549细胞的协同杀伤作用。方法应用MTT法检测高温处理或常温处理细胞对顺铂和榄香烯的敏感性。采用4μg/mL顺铂和15μg/mL榄香烯或60μg/mL榄香烯联合42℃高温处理1.5小时或常温处理,使用MTT法检测细胞抑制率。透射电镜观察细胞形态学改变。结果高温作用后,顺铂对A549细胞的半数抑制浓度（IC50）,从常温时的22.44μg/mL降低至11.74μg/mL;榄香烯对A549细胞的IC50从35.43μg/mL降低至28.68μg/mL;42℃加热1.5小时联合4μg/mL顺铂和15μg/mL榄香烯具有明显的协同杀伤作用,A549细胞可见凋亡形态,可见凋亡小体,同时有大量细胞坏死。结论低浓度榄香烯可以明显提高高温联合顺铂对A549细胞的杀伤作用。     

CIK细胞联合顺铂对卵巢癌耐药细胞SKOV3/CDDP的杀伤作用

目的：探讨细胞因子诱导的杀伤（cytokine-induced killer,CIK）细胞联合顺铂对卵巢癌顺铂耐药细胞SKOV3/CD-DP小鼠腹腔移植模型的体内外杀伤作用。方法：取正常人的外周血单个核细胞（PBMC）,加入IFN-γ、IL-2、CD3McAb和IL-1,体外诱导成CIK细胞。用MTT法测定CIK细胞、顺铂及两者联合对人卵巢癌细胞株SKOV3/CDDP细胞的杀伤活性。在SCID小鼠腹腔内接种卵巢癌SKOV3/CDDP细胞,观察CIK细胞对荷瘤鼠的体内抑瘤作用,并用RIA法检测各组血清中CA125的含量。结果：顺铂对SKOV3/CDDP细胞的IC50为315.5μg/ml,较其对SKOV3细胞的IC50（85μg/ml）增加了4倍;CIK细胞对SKOV3与SKOV3/CDDP细胞的杀伤活性均在48h最高,且随效靶比的增高而增强,其对SKOV3/CDDP细胞的杀伤活性明显高于SKOV3（P〈0.05）。仅25μg/ml的顺铂即可使效靶比为12.5∶1组中的联合杀伤率比单纯顺铂组增加5.8倍,比单纯加CIK（相同效靶比）细胞杀伤率增加2.3倍,且随效靶细胞比值和顺铂浓度的升高呈依赖性增加。与对照组相比,CIK组与CIK＋顺铂组均能显著抑制癌性结节的生长,抑瘤率达100%,且3组SCID鼠血中CA125值有显著性差异（P〈0.05）。结论：正常人CIK细胞联合顺铂对清除晚期卵巢癌表达耐药蛋白的腹腔种植转移病灶可能会有较好的效果,并有希望成为前景良好的综合治疗方案。     

去甲斑蝥酸钠对耐顺铂人肺腺癌细胞系A549/DDP的逆转作用

[目的]探讨去甲斑蝥酸钠(SNCTD)对耐顺铂人肺腺癌细胞系A549/DDP的逆转作用及其对耐药细胞周期的影响。[方法]⑴采用CCK法筛选出SNCTD对A549/DDP的无毒浓度(即对细胞抑制率<10%的药物浓度),并检测出顺铂及与无毒浓度SNCTD联合对耐药细胞株的IC50。⑵光学显微镜下观察无毒浓度SNCTD组、单纯DDP处理组及联合用药组用药48h细胞形态的变化。⑶采用流式细胞仪观察用药48h后正常细胞组、无毒浓度SNCTD组、DDP组及DDP+SNCTD组对A549/DDP细胞周期的影响。[结果]⑴SNCTD对A549/DDP的无毒浓度为5μg/ml,与DDP联合用药降低A549/DDP的耐药逆转倍数为1.97。⑵无毒浓度SNCTD处理耐药细胞组光学显微镜下细胞形态未见明显改变,而联合用药组比单纯DDP作用后细胞形态明显变差。⑶无毒浓度SNCTD处理耐药细胞后细胞周期未见明显改变,单纯DDP处理后细胞阻滞在S期,联合用药后S期减少,G0/G1期细胞增多。[结论]SNCTD对A549/DDP具有耐药逆转作用,与DDP联用对耐药细胞有协同杀伤作用。     

人肺腺癌A549及A549/DDP细胞株差异蛋白质组学分析

 目的 比较人肺腺癌细胞株A549和耐顺铂株A549/DDP细胞的蛋白表达谱,筛选肺癌耐药相关蛋白,为 阐明肿瘤细胞的耐药提供新线索。 方法 对两种细胞株进行比较蛋白质组学研究,利用双向凝胶电泳技术（2-DE）分离细胞总蛋白,经 图像分析软件分析、基质辅助激光解析电离飞行时间质谱（MALDI-TOF-MS）鉴定差异蛋白质点 ,并用免疫细胞化学（ICC）对部分差异蛋白进行验证。 结果 获得分辨率高、重复性好 的A549、A549/DDP总蛋白图谱,初步筛选出差异蛋白质点,经质谱分析及数据库检索,鉴定出 13种差异表达蛋白质,这些蛋白与细胞代谢、结构、解毒和DAN修复、以及信号转导等相关。 结论 A549、A549/DDP细胞株存在差异表达蛋白质点,提示这些蛋白可能与A549细胞耐顺铂相关,为 研究肺癌耐药提供依据。     

人肺腺癌细胞株A549和A549/DDP的比较蛋白质组学研究

目的:比较人肺癌细胞株A549和顺铂(cisplatin,DDP)耐药细胞株A549/DDP中的蛋白表达差异.方法:DDP诱导A549细胞建立DDP耐药细胞株A549/DDP.应用蛋白质组学技术分离鉴定A549和A549/DDP细胞中差异表达的蛋白质,通过real-time PCR、蛋白质印迹法和免疫细胞化学法对部分差异蛋白进行验证;应用生物学信息检索分析差异蛋白的功能.结果:A549和A549/DDP细胞中有8个蛋白质点的表达差异＞5倍,分别为POTE、FH (fumarate hydratase)、PDE (phosphodiesterase)、AKR1C1 (aldo-keto reductase family 1,member C1)、DDH2 (dihydrodiol dehydrogenase 2)、S100A10、prefoldin subunit 2和核内转运蛋白,这些蛋白与细胞代谢、凋亡、增殖、解毒和信号转导等有关.Real-time PCR、蛋白质印迹法和免疫细胞化学法验证结果与蛋白质组学研究结果一致.结论:鉴定得到的A549和A549/DDP细胞中的差异蛋白为研究肺癌细胞DDP耐药提供新依据.     

多药耐药细胞株A549/Gem及其亲代细胞A549之间的区别研究

Objective: To discuss the difference between multi-drug resistant cell line A549/Gem and its parental cell A549 on the basis of establishment of human gemcitabine-resistant cell line A549/Gem so as to elaborate the possible mechanisms of gemcitabine resistance. Methods: Human gemcitabine-resistant non-small cell lung cancer cell line A549/Gem was estab-lished by the method of repeated clinical serous peak concentration plus gradually increasing concentration of gemcitabine from its parental cell human lung adenocaroinoma cell line A549 which was sensitive to gemcitabine. During the course of inducement, we had monitored their morphology, checked their resistance indexes and resistant pedigree by MTT method, gathered their growth curves and calculated their doubling time, examined their DNA contents and cell cycles by FCM; at the same time, we had measured their expressions of P53, EGFR, Cerb-B-2, PTEN, PCNA, c-myc, VEGF, MDR-1, Bcl-2, nm23, MMP-9, TIMP-1, and CD44v6 proteins via immunocytochemistry staining, RRM1 and ERCC1 mRNA by real-time fluorescent quantitative-PCR. Results: The resistance index of A549/Gem' cells (the deputy of cells in the process of inducement) to gemcitabine was 163.228, and the cell line also exhibited cross-resistance to vinorelbine, taxotere, fluorouraci, etoposide and cisplatin, but kept sensitivity to paclitaxol and oxaliplatin. The doubling time of A549/Gem' was shorter and figures in G0-G1 phases were increased than A549 cells. Compared with A549 cells, A549/Gem' cells achieved EGFR and c-myc proteins expressions, nm23 protein expression enhanced, P53, Cerb-B-2 and Bcl-2 proteins expressions reduced, PTEN ,PCNA and MDR-1 proteins expressions vanished, but those of MMP-9, VEGF, CD44v6 and TIMP-1 proteins changed trivially. Meanwhile, expressions of RRM1 and ERCC1 mRNA were augmented markedly. The resistance index of A549/Gem cells to gemcitabine was 129.783, and the cell line also held cross-resistance to vinorelbine, taxotere, etoposide, cisplatin and sensitivity to paclitaxol. But the resistance to fiuorouracil and sensitivity to oxaliplatin vanished. And the expression of RRM1 and ERCC1 mRNA decreased visibly. The doubling time of A549/Gem cells was longer and figures in G0-G1 phases were decreased than A549/Gem' cells. In A549/Gem cells, expressions of P53, EGFR, PCNA and MDR-1 proteins was same to those of A549/Gem' cells. A549/Gem cells achieved TIMP-1 and PTEN proteins expressions, Cerb-B-2, MMP-9, c-myc and Bcl-2 proteins expressions enhanced, nm23 protein expressions vanished, but the expressions of VEGF and CD44v6 proteins changed trivially. Furthermore, Compared with its parental cell A549, A549/Gem cell was mixed with giant cells of different sizes and was larger and more irregular. Conclusion: The human gemcitabine-resistant non-small cell lung cancer cell line A549/Gem had achieved multi-drug resistance and great changes of biological characters compared with its parental cells A549. And these changes possibly participated in the formation of multidrug resistance.     

PTEN及mTOR在人肺腺癌培美曲塞耐药株A549/PEM中的表达

目的:应用高浓度反复间歇法建立人肺腺癌A549培美曲塞耐药细胞株A549/PEM,探讨PTEN、mTOR在人肺腺癌亲本株A549及培美曲塞诱导人肺腺癌耐药株A549/PEM中的表达变化.方法:采用终浓度为500ng/ml的培美曲塞反复间歇冲击建立人肺腺癌A549培美曲塞耐药细胞株A549/PEM,MTT法检测细胞耐药性.RT-PCR、Western blot分别检测PTEN、mTOR在A549及A549/PEM细胞的mRNA及蛋白表达变化.结果:A549/PEM耐药指数为26.87±1.81,较亲本株A549升高约27倍.RT-PCR检测mRNA表达示A549/PEM的PTEN及mTOR基因表达与A549相比均表达上调(P=0.023;P ＜0.01);Western blot检测蛋白表达示A549/PEM的PTEN及mTOR蛋白表达与A549相比均表达上调(P＜0.01;P =0.04).结论:高浓度反复间歇法可成功建立人肺腺癌A549培美曲塞耐药细胞株模型;PTEN、mTOR表达变化可能与培美曲塞获得性耐药相关.     

LyGDI对肺癌A549细胞放射敏感性影响的观察

目的:研究X射线对稳定转染鸟苷解离抑制因子(LyGDI)A549细胞株放射敏感性的影响及相关机制。方法:应用生长曲线观察细胞增殖能力,流式细胞术检测不同剂量照射后转染组和对照组细胞的周期分布及凋亡率,克隆形成试验观察转染组细胞放射敏感性。结果:转染组细胞相对于对照组增殖能力减弱,F=212.55,P<0.01;克隆形成能力减弱,放射敏感性增加,F=7.56,P<0.05;流式细胞术检测到辐射诱导凋亡增加,F=18.45,P<0.01;细胞周期检测提示转染组G2期阻滞受抑制,F=6.29,P<0.05。结论:过度表达的LyGDI上调A549细胞放射敏感性,其可能机制为抑制G2期阻滞促进凋亡。     

siMDR1重组慢病毒载体的构建及其对A549和A549／DDP细胞的影响

背景与目的:肿瘤细胞的多药耐药性(multidrug resistance,MDR)是导致化疗失败的最主要原因,也是癌症术后复发及转移的主要原因.本研究旨在探讨MDR1基因RNA干扰(RNA interference,RNAi)重组慢病毒对人肺腺癌A549细胞和对顺铂耐药的A549/DDP细胞的MDR1基因的抑制作用.方法:设计获得针对MDR1的短发卡状RNA(small hair pin RNA,shRNA)的寡核苷酸序列,退火后插入线性化的pSUPER载体(H1启动子下游).把构建获得的载体转染A549细胞,RT-PCR法检测其对MDR1的干扰作用,筛选确定MDR1基因RNAi有效靶序列;合成靶序列的01igo DNA,与含启动子和绿色荧光蛋白(green fluorescent protein,GFP)的PTM载体连接产生PTM-siMDR1慢病毒载体;用重组慢病毒体外感染A549和A549/DDP细胞.结果:成功构建可以表达针对MDR1的发卡状RNAi,能有效的下调MDR1的表达.成功构建获得针对MDR1基因的慢病毒载体PTM-siMDR1,包装慢病毒,浓缩病毒悬液的滴度为0.5×109TU/mL.感染PTM-siMDRI的A549/DDP细胞对顺铂的敏感性明显提高,逆转倍数达3.81倍.结论:siiDR1重组慢病毒载体感染A549/DDP细胞,能明显改善其对顺铂的耐药性.     

沉默表皮生长因子受体的表达对肺腺癌A549细胞自噬的影响

目的：研究降低表皮生长因子受体（EGFR）的表达对肺腺癌A549细胞自噬活性的影响。方法：A549细胞中加入EGF处理,分为4组,即未处理组和10、25、50 ng/mL EGF处理组,用Western blot方法检测EGFR的蛋白表达;采用转染siRNA降低肺腺癌细胞A549细胞EGFR的表达,将A549细胞分为4组,即未处理组、EGFR siRNA-1组、EGFR siRNA-2组和EGFR siRNA-3组,分别采用Real-time RT-PCR和Western blot方法检测EGFR mRNA和蛋白表达水平来评价3个siRNA的沉默效果;将A549细胞分为转染EGFR siRNA组、转染空载体组、转染试剂组（只加入等量转染试剂）及未处理组,且4组均加入等量的50 ng/mL EGF,用Western blot检测LC3Ⅱ/LC3Ⅰ蛋白表达,观察沉默EGFR表达对自噬活性变化;A549细胞分为转染EGFR siRNA组和转染空载体组,用透射电子显微镜观察自噬小体。结果：转染siRNA后A549细胞EGF蛋白的表达降低,LC3Ⅰ向LC3Ⅱ的转化水平升高（P < 0.05）,细胞内出现较多自噬小体,自噬活性明显增加。结论：降低EGFR的表达可以提高肺腺癌A549细胞自噬活性。     

顺铂诱导A549细胞凋亡的研究

目的 探讨顺铂诱导肺癌细胞凋亡的规律，机制以及在肿瘤化疗中的作用。方法 应用形态学观察，琼脂糖凝胶电泳，原位DNA断裂点的末端标记法和流式细胞仪分析技术，检测顺铂诱导A549细胞的凋亡作用。结果 3mg/L顺铂诱导的细胞凋亡在12-72h持续存在并逐渐增强，呈时间依赖性；顺铂浓度分别为1、3、5、7mg/L时均诱导了细胞凋亡，呈浓度依赖性，在顺铂作用下，细胞被阻滞于G1期。结论 诱导细胞凋亡可能是顺铂抗肿瘤作用的重要机制。     

沉默COX-2抑制A549细胞的恶性增殖

Objective: The aim of this study was to explore the effects on malignant proliferation of A549 cell by silencing cy-clooxygenase (COX)-2. Methods: In the present study, we constructed three siRNA vectors producing small interference RNA. The siRNA vectors and the vacant vectors were transfected into A549 cell with lipofectamine respectively and the transfected cell strains were constructed. The change of COX-2 expression levels was examined by Western blot and RT-PCR. The effects on the proliferation of lun...     

A new biomarker in monitoring breast cancer: CA 549

Serum biomarkers are not very reliable in assessing outcome or predicting recurrence of breast cancer. Clinically, carcinoembryonic antigen (CEA) is widely used and is elevated in a majority of patients with metastatic breast cancer. However, it is falsely elevated in a wide range of nonmalignant conditions and correlates poorly with disease progression. We evaluated a newly described monoclonal antibody, CA 549, in an immunoradiometric assay which uses two monoclonal antibodies directed against tumor and milk fat globule membranes. CA 549 and CEA were studied in 682 patients, 331 of whom had breast diseases and 99 of whom were followed with multiple serum samples. Of 69 patients with benign breast diseases, 1.5% had elevated CA 549, 0% of 30 pregnant women had elevated CA 549, and 26% of patients with nonmalignant liver disease had CA 549 elevation. In metastatic cancer of prostate, ovary, endometrium, colon, and lung CA 549 was elevated in 12% to 50% of cases with levels less than 120 U/mL. In breast cancer, CA 549 was elevated in 11% of 88 patients who received adjuvant chemotherapy and had no evidence of metastasis; in 23% of 16 patients in complete remission after chemotherapy; in 63% of 52 patients in partial remission after therapy; and in 83% of 106 patients with progression of breast cancer compared with 63% with elevated CEA (P = .001). In diseases of the breast, CA 549 has a sensitivity In diseases of the breast, CA 549 has a sensitivity and specificity of 77% and 92% v 61% and 92% for CEA. Of 99 patients serially monitored with clinically documented breast cancer progression, regression, or stability of disease, CA 549 was statistically significantly superior to CEA in monitoring a greater than 25% change in those patients with metastatic progression (P = .03). CA 549 is a new serum marker that should be control tested in prospective clinical trials alone or in conjunction with other markers.