尼美舒利和舒林酸对人胃癌SGC-7901细胞COX-2和VEGF表达的影响及意义

目的观察尼美舒利、舒林酸对人胃癌SCK2-7901细胞环氧化酶2（COX-2）和血管内皮生长因子（VEGF）表达的影响,初步探讨尼美舒利、舒林酸抑制肿瘤血管生成机制。方法对人胃癌SCA2-7901细胞进行细胞培养,免疫组织化学、蛋白质印迹（Western lot）方法检测不同浓度尼美舒利、舒林酸作用后细胞COX-2、VEGF表达的改变。结果尼美舒利100、200μmol／L及舒林酸0．6、1．2mmol／L作用48h后人胃癌SCK2-7901细胞COX-2、VEGF蛋白表达率与阴性对照组相比明显降低（P〈20．05）,并且COX2与VEGF之间具有相关性（P〈005）。随着药物浓度的升高COX2和VEGF表达逐渐减弱。结论抑制COX-2的表达及由此引起的VEGF蛋白表达降低。在非甾体类抗炎药（NSAIDs）抑制肿瘤血管生长机制中可能具有一定作用。     

阿司匹林对结肠癌细胞肿瘤干性标记物CD44蛋白表达的影响

目的研究人结肠癌细胞系SW-480、HT-29中肿瘤干细胞干性标记物CD44蛋白受阿司匹林不同药物浓度的影响变化,从而探讨阿司匹林是如何预防结直肠癌的发生。方法采用激光扫描共聚焦显微技术:免疫荧光双标染色法检测结肠癌细胞系SW-480、HT-29中CD44的表达;用Western blotting检测不同浓度阿司匹林(0、2.5、5.0、10.0 mmol/L,即分别为空白对照组、低浓度组、中浓度组、高浓度组)作用下,CD44在COX-2阴性表达的SW-480细胞及COX-2高表达的HT-29细胞表达影响。结果 SW-480、HT-29中存在CD44阳性细胞,2种细胞表达的CD44荧光值比较,差异有统计学意义(P<0.05);Western blotting结果显示阿司匹林能抑制结肠癌细胞系SW-480、HT-29中CD44的表达,且具有明显的量-效关系(P<0.05),2种细胞组间比较,差异无统计学意义(P>0.05)。结论结肠癌细胞系SW-480、HT-29中存在CD44阳性细胞,阿司匹林能抑制肿瘤干细胞干性标记物CD44的表达,其抑制可能是通过COX-2及非COX-2途径,该抑制作用可能是阿司匹林能预防结肠癌的原因之一。     

卡培他滨联合阿司匹林对SGC-7901细胞增殖的体外抑制作用

目的探讨卡培他滨联合阿司匹林对SGC-7901细胞增殖和凋亡的体外抑制作用及其作用机制。方法体外培养SGC-7901细胞,MTT法检测卡培他滨1.0μmol/L与阿司匹林0.5、1.0、3.0 mmol/L单用和联用对SGC-7901细胞体外增殖的抑制作用;倒置相差显微镜观察卡培他滨1.0μmol/L与阿司匹林3.0 mmol/L单独及联合用药对SGC-7901细胞形态的影响;PI/Annexin V-FITC双染色流式细胞术分析卡培他滨1.0μmol/L与阿司匹林3.0 mmol/L单独及联合用药诱导SGC-7901的细胞凋亡率;Western blotting分析卡培他滨1.0 mmol/L与阿司匹林3.0 mmol/L单独及联合用药对COX-2、VEGF表达的影响。结果卡培他滨与阿司匹林对SGC-7901细胞均有生长抑制作用,且联合组的抑制率高于卡培他滨组和阿司匹林组,两组间比较差异具有统计学意义(P0.05)。用药处理24 h后,在显微镜下可观察到SGC-7901细胞发生细胞凋亡的形态学改变,联合组相对于卡培他滨、阿司匹林单独用药组的变化更明显。PI/Annexin V双染分析表明,卡培他滨1.0μmol/L+阿司匹林3.0 mmol/L联合组的细胞凋亡率明显高于阿司匹林3.0 mmol/L组或卡培他滨1.0μmol/L组。阿司匹林3.0 mmol/L、卡培他滨1μmol/L以及卡培他滨1.0μmol/L+阿司匹林3.0 mmol/L联合组电泳可以检测出环氧合酶-2(COX-2)、血管内皮生长因子(VEGF)的特异蛋白条带。阿司匹林单用时,COX-2表达量受到抑制(P0.01),蛋白表达下调,而VEGF表达无明显抑制;卡培他滨单用时,VEGF表达量受到抑制(P0.01),蛋白表达下调,而COX-2表达无明显抑制;卡培他滨联合阿司匹林处理时,SGC-7901细胞的COX-2、VEGF表达量均受到抑制(P0.01),同时下调COX-2及VEGF蛋白表达。结论卡培他滨联合阿司匹林能够明显抑制胃癌SGC-7901细胞的增殖,并促进其凋亡,其作用机制与COX-2、VEGF蛋白表达的调控有关。     

茶多酚对肺癌PG细胞生长的调控研究

目的：探讨茶多酚对人PG细胞生长的影响。方法：采用MTT法体外观察不同浓度茶多酚对PG细胞的杀伤作用；应用激光共聚焦显微镜和流式细胞仪分析，检测用药后PG细胞内Ca^2 浓度，CD44V6表达和细胞增殖周期分布的变化。结果：3个浓度的茶多酚对PG2细胞的有杀伤作用，呈剂量依赖分析。细胞增殖受到明显抑制，使细胞阻滞于G0／G1期，不能进入S期及G2／M期，细胞增殖指数明显下降。细胞内Ca^2 浓度与对照组相比，逐渐上升；CD44V6表达水平则呈逐渐下降。结论：茶多酚对PG细胞的生长具有抑制作用，其作用机制与改变细胞内Ca^2 浓度和CD44V6表达有关。     

新加沙参麦冬煎剂抑制肿瘤转移及其作用机制的实验研究

目的 探讨新加沙参麦冬煎剂防治肿瘤转移的机制。方法结合动物模型、免疫组化、细胞分子生物学技术，观察新加沙参麦冬煎剂对荷瘤小鼠抑瘤率、转移抑制率、生命延长率的影响，检测实验小鼠皮下移植瘤血管内等细胞生长因子（VEGF）、血管内皮细胞第Ⅷ因子（CD34）、黏附因子（CD44V6）、基质金属蛋白酶2（MMP2）、基质金属蛋白酶抑制酶（TIMP2）的表达情况。结果新加沙参麦冬煎剂治疗组的瘤重抑制率、肺转移抑制率、生命延长率分别为37.3%，58.3% 和20.8%；皮下移植瘤CD44V6 、VEGF表达、微血管密度（MVD）明显低于空白组（P＜0.01），TIMP2表达记分明显高出其他组（P＜0.01）。小鼠肺转移灶数与VEGF 、CD44V6、MVD呈线性相关，相关系数分别为0.490，0.398，0.455。结论①新加沙参麦冬煎剂对小鼠LA795高转移肺腺癌模型有较好抑制转移、抑制肿瘤生长和延长荷瘤小鼠生存时间的作用。②新加沙参麦冬煎剂可通过调控肿瘤转移过程中黏附、基质降解、血管生成相关分子的表达，多途径、多靶点防治肿瘤的转移。     

茶多酚对肺癌PG细胞生长的调控研究

目的:探讨茶多酚对人PG细胞生长的影响。方法:采用MTT法体外观察不同浓度茶多酚对PG细胞的杀伤作用;应用激光共聚焦显微镜和流式细胞仪分析,检测用药后PG细胞内Ca2 +浓度、CD44 V6表达和细胞增殖周期分布的变化。结果:3个浓度的茶多酚对PG细胞均有杀伤作用,呈剂量依赖关系。细胞增殖受到明显抑制,使细胞阻滞于G0 / G1期,不能进入S期及G2 / M期,细胞增殖指数明显下降。细胞内Ca²⁺浓度与对照组相比,逐渐上升;CD44 V6表达水平则呈逐渐下降。结论:茶多酚对PG细胞的生长具有抑制作用,其作用机制与改变细胞内Ca2 +浓度和CD44 V6表达有关     

CD44V6、VEGF与非小细胞肺癌的相关性研究

目的研究非小细胞癌中CD44v6、VEGF表达与临床生物学行业相关性。方法回顾分析60例非小细胞肺癌的切除标本,采用免疫组化法检测肺癌组织中VEGF和CD44v6的表达,并分析临床意义。结果在非小细胞肺癌中,CD44V6和VEGF表达之间存在着正相关关系（OR=0.352）。两者共阳性组中淋巴结转移率为75%（24/32）,明显高于阴性者16.7%（1/6）,差别有显著意义（P〈0.05）。结论非小细胞肺癌患者中CD44V6和VEGF蛋白表达呈正相关,联合检测VEGF和CD44v6的表达对于非小细胞肺癌淋巴血行转移和病理分期的评估有一定临床意义,可指导临床选择正确的综合治疗方案。     

VEGF及CD44V6在胃癌中的表达及意义

目的 探讨血管内皮生长因子(vascular endothelial growth factor,VEGF)及粘附分子CD44的变构体CD44V6在胃癌中的表达与淋巴转移及临床分期的关系.方法 应用免疫组化SP法检测53例胃癌中,VEGF、CD44V6的表达情况.结果 53例胃癌组织中,VEGF、CD44V6的阳性表达率分别为79.2%(42/53)、64.2%(34/53),VEGF及CD44V6的阳性率与淋巴转移和临床分期呈正相关,差异有显著性(P＜0.05).结论 VEGF、CD44V6在胃癌中的过度表达在胃癌的发生、发展中可能协同起作用,并可作为判断胃癌生物学行为的指标.     

二氢青蒿素联合环氧化酶2抑制剂抗S180肉瘤作用机制研究

目的探讨二氢青蒿素联合环氧化酶2抑制剂对S180肉瘤的生长抑制作用及其可能的机制。方法采用ICR小鼠皮下移植瘤模型,观察二氢青蒿素联合环氧化酶2抑制剂对小鼠S180肉瘤生长抑制作用,以及对肿瘤COX-2、VEGF、CD31蛋白表达与白细胞数目的影响。结果二氢青蒿素分别以50、100、150mg·kg-1剂量与环氧化酶2抑制剂美洛昔康10mg·kg-1剂量合用能明显抑制S180肉瘤的生长,抑瘤率最高达55.38%,优于两药单用的效果;免疫组织化学检测表明,3个剂量的二氢青蒿素合用环氧化酶2抑制剂的肿瘤组织COX-2、VEGF及CD31蛋白的表达量均下降;Westernblot方法检测得在高剂量二氢青蒿素(150mg.kg-1.d-1)联合应用美洛昔康(10mg.kg-1.d-1)组VEGF和COX-2蛋白的表达量均有下降,与模型对照组差异有显著性(P<0.05);RT-PCR检测得各合用药物组的肿瘤组织VEGFmRNA表达量均减少(P<0.05)。结论二氢青蒿素联合环氧化酶2抑制剂能明显抑制S180肉瘤的生长,其机制可能与下调肿瘤组织中COX-2和VEGF的表达有关。     

环氧合酶-2及其抑制剂在胰腺癌血管靶向治疗中的作用

胰腺癌的诊治目前仍是医学界的难题,血管生成是胰腺癌生长和转移的必要因素。环氧合酶(cyclooxygenase,COX)为花生四烯酸代谢过程中的关键酶,存在COX-1及COX-2两种同工酶,其中COX-2在胰腺癌的发生发展及胰腺癌血管生成中发挥重要作用。COX-2抑制剂可分为非选择性及选择性两种,两种COX-2抑制剂都对胰腺癌及其血管形成的发生与进展存在抑制作用,COX-2抑制剂抗肿瘤血管形成的机制可能是抑制血管内皮生长因子(VEGF)、缺氧诱导因子-1及基质金属蛋白酶(MMP)的表达、降低前列腺素(PGs)及其他血管生成因子的表达、促进内皮细胞凋亡、抑制内皮细胞侵袭力和影响一氧化氮合酶(NOS)的表达。     

阿司匹林对S180肿瘤生长及血管生长相关因子表达的抑制作用

目的　从抗血管生成的角度研究阿司匹林(Asp)预防和治疗肿瘤的机理。方法　昆明种小鼠随机分为对照组 ,替加氟组 ,Asp 5 0 ,2 5 ,10mg·kg- 1组 ,于接种S180肿瘤细胞后d 2开始ig给药 ,连续9d ,观察抑瘤率。采用免疫组化的方法研究Asp对肿瘤组织环氧合酶 2 (COX 2 )及血管相关生长因子的作用。结果　Asp 3个剂量组均有一定的抑瘤作用 ,大剂量抑瘤率为 2 1.1%。免疫组化染色显示Asp对肿瘤组织的COX 2表达有明显的抑制作用 ,同时血管生长相关因子血管内皮生长因子、纤维细胞生长因子 2表达也明显下调 ,肿瘤组织微血管密度明显降低。结论　Asp对S180肿瘤有抑制作用 ,它可以抑制与血管生长相关的COX 2的表达而抑制肿瘤血管的生长 ,进而抑制肿瘤的生长。抑制肿瘤血管的生长可能是Asp预防和治疗肿瘤的机理之一。     

阿司匹林抑制ox-LDL诱导内皮细胞炎症分子表达的研究

目的评价阿司匹林对ox-LDL刺激内皮细胞炎症蛋白表达的影响。方法使用培养人脐带内皮细胞,用氧化型低密度脂蛋白刺激内皮细胞16h,终止反应后用SDS-PAGE分离蛋白,使用Western Blot分析蛋白表达的变化。ROS测定使用DCFH-DA荧光标记,用流式细胞仪测定荧光强度。结果①阿司匹林抑制ox-LDL诱导内皮细胞COX-2表达。使用ox-LDL刺激内皮细胞16h,COX-2表达增加,分别用2.5mmol·L-1和5mmol·L-1阿司匹林处理内皮细胞30min后,COX-2表达明显降低。②阿司匹林降低ox-LDL诱导的内皮细胞ICAM-1表达。ox-LDL刺激内皮细胞16h后,Western Blot结果显示ICAM-1内皮细胞表达明显增加。用免疫荧光染色的方法观察细胞获得了同样的结果,ox-LDL刺激后ICAM-1在内皮细胞膜上表达明显增加,阿司匹林处理后减少了ICAM-1在膜上的表达。③阿司匹林轻度抑制ox-LDL诱导内皮细胞ROS产生。0.3g·L-1ox-LDL刺激内皮细胞16h后细胞内ROS明显增高,但阿司匹林仅部分阻止ROS的产生。结论非甾体类抗炎药物阿司匹林对ox-LDL诱导COX-2、ICAM-1有明显的抑制作用,但不能完全阻止ox-LDL诱导的ROS产生。这些结果表明阿司匹林能够减轻氧化脂质诱导的内皮细胞炎症损伤反应。     

Sulindac derivatives inhibit growth and induce apoptosis in human prostate cancer cell lines.

We examined the activity of two metabolites of sulindac (a nonsteroidal anti-inflammatory drug), sulindac sulfide and sulindac sulfone (exisulind, Prevatec), and a novel highly potent analog of exisulind (CP248) on a series of human prostate epithelial cell lines. Marked growth inhibition was seen with the BPH-1, LNCaP, and PC3 cell lines with IC50 values of about 66 microM, 137 microM, and 64 nM for sulindac sulfide, exisulind, and CP248, respectively. DNA flow cytometry and 4',6'-diamido-2-phenylindole (DAPI) staining indicated that these three compounds also induced apoptosis in all of these cell lines. Similar growth inhibition also was seen with the PrEC normal human prostate epithelial cell line, but these cells were resistant to induction of apoptosis at concentrations up to 300 microM, 1 mM, and 750 nM of sulindac sulfide, exisulind, and CP248, respectively. Derivatives of LNCaP cells that stably overexpress bcl-2 remained sensitive to growth inhibition and induction of apoptosis by these compounds. In vitro enzyme assays indicated that despite its high potency in inhibiting growth and inducing apoptosis, CP248, like exisulind, lacked cyclooxygenase (COX-1 and COX-2) inhibitory activity even at concentrations up to 10 mM. Moreover, despite variations of COX-1 and COX-2 expression, the three benign and malignant prostate cell lines showed similar sensitivity to growth inhibition and induction of apoptosis by these three compounds. Therefore, sulindac derivatives can cause growth inhibition and induce apoptosis in human prostate cancer cells by a COX-1 and -2 independent mechanism, and this occurs irrespective of androgen sensitivity or increased expression of bcl-2. These compounds may be useful in the prevention and treatment of human prostate cancer.     

Peroxisome proliferator-activated receptor-gamma is a target of nonsteroidal anti-inflammatory drugs mediating cyclooxygenase-independent inhibition of lung cancer cell growth

Nonsteroidal anti-inflammatory drugs (NSAIDs) inhibit the growth of different cancer cell types, suggesting a broad role for their cyclooxygenase (COX) targets and eicosanoid products in tumor cell growth. Sulindac sulfide, a COX inhibitor, inhibited the growth of non-small-cell lung cancers (NSCLC) both in soft agar and as xenografts in nude mice. Importantly, the concentration of sulindac sulfide required to inhibit NSCLC cell growth greatly exceeded the concentration required to inhibit prostaglandin (PG) E(2) synthesis in NSCLC cells, suggesting that NSAID inhibition of cell growth is mediated by additional targets distinct from COX. Both sulindac sulfide and ciglitazone, a defined peroxisome proliferator-activated receptor-gamma (PPARgamma) agonist, stimulated a promoter construct containing a PPAR response element linked to luciferase and potently inhibited NSCLC cell growth at similar concentrations, indicating a role for PPARgamma as a target of NSAID action in these cells. Overexpression of PPARgamma in NSCLC cells strongly inhibited the transformed growth properties of the cells, providing a molecular confirmation of the results obtained with the PPARgamma agonists. Increased expression of PPARgamma, as well as ciglitazone and sulindac sulfide induced expression of E-cadherin, which has been linked to increased differentiation of NSCLC. Despite the fact that SCLC cell lines expressed little or no cytosolic phospholipase A(2), COX-1, or COX-2, sulindac sulfide and PPARgamma agonists also inhibited the transformed growth of these lung cancer cells. We propose that PPARgamma serves as a target for NSAIDs that accounts for COX-independent inhibition of lung cancer cell growth.     

The influence of cyclooxygenase-1 expression on the efficacy of cyclooxygenase-2 inhibition in head and neck squamous cell carcinoma cell lines

We have previously observed that cyclooxygenase-2 (COX-2) inhibition blocked the production of vascular endothelial growth factor (VEGF) in some head and neck squamous cell carcinoma (HNSCC) cells. However, as some HNSCC cells showed little response to COX-2 inhibition, although they highly expressed COX-2 and prostaglandin E2, we set out to elucidate what made this difference between them and focused on the possibility of the differential expression of COX-1. In western blotting, we found that COX-1 was expressed in SNU-1041 and SNU-1066, but not in SNU-1076 and PCI-50. Only in those cell lines without expression of COX-1 was VEGF production blocked meaningfully by small interfering RNA of COX-2. However, by cotreating with small interfering RNAs of COX-2 and COX-1, VEGF synthesis and prostaglandin E2 were inhibited in SNU-1041 and SNU-1066, similarly in SNU-1076 and PCI-50 with high expression of only COX-2. We also found that there was no difference in the pattern of prostaglandin synthesis between COX-2 and COX-1 through enzyme-linked immunosorbent assay for various prostaglandins. Our study suggests that, as COX-1 and COX-2 express and affect VEGF synthesis in HNSCC cells, we should check COX-1 expression in investigations on cancer treatment by inhibiting COX-2-induced prostaglandins.