多胺生物合成抑制剂DFMO抗裸鼠移植人大肠癌的实验研究

A human colon cancer cell line Hce-8693 was heterotransplanted in nude mice. polyamine biosynthesis inhibitor alpha-difluoromethylornithine (DFMO) showed a marked reproducible inhibition in this model. The size and weight of transplanted tumor in DFMO group were smaller than those of the control group and the average inhibition rate was 72.8% (P less than 0.001). DFMO showed higher tumor inhibitory rate than 5-Fu (35.4%) (P less than 0.001). Furthermore, DFMO demonstrated less severe bone marrow inhibition in the nude mice than 5-Fu (20.0% vs 53.2%, P less than 0.001). There was no synergistic action in these two drugs at the experimental doses. The concentration of putrescine and spermidine in the serum and tumor tissue in the DFMO group were 70% lower than those of the control group (P less than 0.001). These results indicate that the anti-tumor effect of DFMO might be explained by the inhibition of polyamine biosynthesis and this study provides an experimental basis for future clinical application of DFMO.     

雷替曲塞对人胃癌裸鼠移植瘤生长的影响及其机制

  目的   初步探索雷替曲塞对人胃癌裸鼠皮下移植瘤生长的影响及其机制。   方法   1）建立人胃癌细胞MGC-803裸鼠皮下移植瘤模型；2）药物干预后观察荷瘤鼠一般情况、体重、瘤重并计算抑瘤率；3）流式细胞仪测定瘤细胞的周期分布和凋亡；4）采用RT-PCR、Western blot印迹法检测各组肿瘤p53 mRNA及p53蛋白的表达水平。   结果   经雷替曲塞及5-Fu作用后，与对照组相比，两组裸鼠的体重明显下降，瘤体积缩小，抑瘤率分别达到49.02%和45.75%。雷替曲塞组和5-Fu组瘤细胞的G₀/G₁期比例较对照组比例明显降低（P < 0.01），而S期比例较对照组明显升高（P < 0.01）。雷替曲塞组和5-Fu组裸鼠肿瘤p53 mRNA与蛋白表达水平均显著升高（P < 0.01），但雷替曲塞组和5-Fu组之间并无差异。   结论   1）雷替曲塞对人胃癌细胞MGC-803裸鼠移植瘤生长有抑制作用，且与5-Fu抑瘤效果相似；2）雷替曲塞可以诱导人胃癌细胞MGC-803裸鼠移植瘤细胞周期S期的阻滞，并诱导移植瘤细胞凋亡；3）雷替曲塞可通过上调p53 mRNA和蛋白的表达水平来发挥抑瘤作用。       

豆蔻提取物对人胃癌裸鼠移植瘤生长及血管生成的影响

[目的]观察豆蔻提取物对人胃癌细胞裸鼠移植瘤的生长和对肿瘤血管生成的影响。[方法]建立人胃癌SGC-7901细胞裸鼠皮下移植瘤模型（n=24）,随机分成4组（n=6）,对照组、豆蔻组、5-Fu组、联合组,各组按设计剂量给药。测定移植瘤体积、瘤重及抑瘤率;用免疫组化法检测各组移植瘤瘤体中血管内皮生长因子（VEGF）和微血管密度（MVD）的表达情况。[结果]豆蔻组、5-Fu组、联合组的瘤重和瘤体积明显低于对照组（P〈0.05）,3组抑瘤率分别为45.83%、66.96%和77.28%。联合组中VEGF表达率和MVD计数明显低于对照组（P〈0.05）。[结论]豆蔻提取物可抑制胃癌移植瘤的生长,与5-Fu联合应用具有协同作用,其作用机制可能与下调VEGF的表达、减少MVD有关。     

膈下逐瘀汤逆转裸鼠移植瘤MDR-1表达的实验

目的 探讨膈下逐瘀汤对HCT-8/5-Fu裸鼠移植瘤多药耐药基因MDR-1表达的影响。方法 MTT法确认人结肠腺癌细胞HCT-8/5-Fu的耐药性及对其他化疗药VCR、VP-16、DDP的交叉耐药性后,将耐药细胞HCT-8/5-Fu接种于BABL/c无胸腺裸鼠右腋下,建立耐药性稳定的裸鼠移植瘤模型。移植瘤裸鼠模型随机分为四组：空白对照组(对照组)、5-Fu组、膈下逐瘀汤组(DSED组)、膈下逐瘀汤+5-Fu组(DSED+5-Fu组)。其中对照组予0.9%氯化钠溶液灌胃给药,其余组予腹腔注射5-Fu和(或)中药灌胃。连续给药14天后颈椎脱臼处死裸鼠。观察各组裸鼠移植瘤生长情况;RT-PCR法检测各瘤组织MDR-1 mRNA表达。结果 膈下逐瘀汤+5-Fu组、膈下逐瘀汤组、5-Fu组对裸鼠移植瘤的抑瘤率分别为54.9%、32.4%和7.0%（P<0.01）。RT-PCR结果显示膈下逐瘀汤+5-Fu组及膈下逐瘀汤组MDR-1 mRNA的表达量与对照组相比明显下降（P<0.01）,5-Fu组与对照组相比MDR-1 mRNA表达量略有升高,但差异无统计学意义。结论 膈下逐瘀汤对大肠癌多药耐药裸鼠移植瘤生长具有抑制作用,其机制可能与膈下逐瘀汤通过逆转耐药移植瘤多药耐药基因表达,增强肿瘤细胞对药物的敏感度。     

全反式维甲酸诱导荷瘤裸鼠EC9706食管癌细胞凋亡的机制

目的 探讨全反式维甲酸(ATRA)诱导荷瘤裸鼠EC9706食管癌细胞凋亡的作用机制.方法 将食管癌EC9706细胞接种于裸鼠,成瘤后将裸鼠分为ATRA作用组、5-氟尿嘧啶(5-Fu)作用组、联合用药组和空白对照组,每组10只,腹腔内连续给药10 d后处死裸鼠.采用原位末端标记(TUNEL)法,检测各组裸鼠移植瘤组织中的细胞凋亡情况.采用免疫组化SP法和逆转录-聚合酶链反应(RT-PCR),检测caspase-3和survivin蛋白及mRNA的表达水平.结果 ATRA作用组、5-Fu作用组和联合用药组的细胞凋亡率分别为44.3%、39.7%和91.0%,均明显高于空白对照组(0.7%,均P＜0.01).空白对照组caspase-3蛋白表达水平为46.12±0.33,caspase-3 mRNA的相对表达量为0.14±0.03,均显著低于ATRA作用组、5-Fu作用组和联合用药组(P＜0.05).空白对照组survivin蛋白表达水平为96.07±0.13,survivin mRNA的相对表达量为0.84±0.04,均显著高于ATRA作用组、5-Fu作用组和联合用药组(均P＜0.05).ATRA作用组与5-Fu作用组的细胞凋亡率、caspase-3和survivin蛋白及mRNA的表达差异均无统计学意义(均P＞0.05),但单药组与联合用药组的差异均有统计学意义(均P＜0.05).结论 ATRA可诱导荷瘤裸鼠EC9706细胞产生凋亡,其作用机制与下调survivin蛋白和mRNA的表达以及上调caspase-3蛋白和mRNA的表达有关.     

蟾酥脂质微球注射液对四种荷瘤裸鼠肿瘤生长的抑制作用

目的:观察蟾酥脂质微球注射液对荷人肝癌Hep G2、人食管癌EC9706、人结肠癌HCT-8和人胃癌BGC 803瘤株裸鼠肿瘤生长的抑制作用.方法:在BALB/c-nu裸鼠右前肢腋下接种4种人癌细胞株建立荷瘤动物模型,移植10 d后采用均衡法随机分为5组,即蟾酥脂质微球注射液高剂量组(2.50 mg/kg)、中剂量组(1.25 mg/kg)、低剂量组(0.63 mg/kg)以及阳性药组(氟尿嘧啶注射液,1.25 mg/kg)和阴性对照组(等体积脂质微球空白注射液),每组7只裸鼠,给药体积0.2 ml.采用尾静脉注射方法给药,各组动物于分组后每周给药2次,连续给药6次.于给药后动态检测并计算各组肿瘤体积(Vt)、肿瘤相对体积(VRT)、肿瘤增殖率(T/C),末次给药后3 d检测并计算各组肿瘤质量和抑瘤率.结果:各组裸鼠给药前肿瘤体积均无显著性差异.荷人肝癌Hep G2细胞瘤裸鼠给药7 d后,各剂量组肿瘤体积和相对肿瘤体积均较阴性对照组明显降低(P<0.05),末次给药后中、高剂量组T/C值<40%,各剂量组的平均肿瘤质量均较阴性对照组明显降低(P<0.05),高剂量组的抑瘤率为74.07%.荷人食管癌EC9706瘤裸鼠末次给药后,各剂量组肿瘤体积和相对肿瘤体积均较阴性对照组明显降低(P<0.05),中、高剂量组T/C值<40%,各剂量组的平均肿瘤质量均较阴性对照组明显降低(P<0.05),高剂量组的抑瘤率为70.38%.荷人结肠癌HCT-8细胞瘤裸鼠末次给药后,各剂量组肿瘤体积和相对肿瘤体积均较阴性对照组明显降低(P<0.05),高剂量组T/C值<40%,各剂量组的平均肿瘤质量均较阴性对照组明显降低(P<0.05),高剂量组的抑瘤率为52.42%.荷人胃癌BGC 803细胞瘤裸鼠末次给药后,中、高剂量组的肿瘤体积和相对肿瘤体积均较阴性对照组明显降低(P<0.05),各剂量组T/C值>40%,各剂量组的平均肿瘤质量均较阴性对照组明显降低(P<0.05),高剂量组的抑瘤率为47.42%.结论:蟾酥脂质微球注射液具有确切的抑制人肝癌Hep G2、食管癌EC9706、结肠癌HCT-8和胃癌BGC 803瘤株增殖的作用,作用效果以抑制人肝癌Hep G2和人食管癌EC9706瘤株生长作用为最佳.     

半枝莲对结直肠癌裸鼠皮下移植瘤生长的抑制作用及其机制

目的观察半枝莲提取物对人结直肠癌裸鼠皮下移植瘤生长的抑制作用,并探讨其作用机制。方法建立人结直肠癌裸鼠皮下移植瘤模型,将24只小鼠随机分为模型组、5-Fu组(阳性对照)、半枝莲低剂量组和半枝莲高剂量组,观察并记录各组裸鼠移植瘤的生长情况,计算肿瘤抑制率。Western blot和免疫组织化学法检测各组裸鼠皮下移植瘤中TWIST和MMP-2表达水平,并分析其相关性。结果半枝莲高剂量组移植瘤瘤重和体积均较模型组明显减轻或缩小,高剂量组抑瘤率与5-Fu组差异无统计学意义(P>0.05);半枝莲高剂量组移植瘤TWIST和MMP-2的表达较模型组均明显降低(P<0.05),与阳性药5-Fu相当。结论一定剂量的半枝莲对人结直肠癌移植瘤具有明显的抑制作用,其机制可能与抑制TWIST和MMP-2的协同表达有关。     

天然14肽生长抑素联合5-Fu对胃癌移植瘤的抑制作用

目的 观察14肽生长抑素(SST-14)及其联合5-Fu对BGC-823、MKN-28人胃癌细胞移植瘤生长抑制及血管内皮生长因子(VEGF)表达的影响。方法 构建BGC-823、MKN-28人胃癌细胞移植瘤模型,随机分为对照组、SST-14组、5-Fu组、联合组,腹腔注射药物治疗3周后处死裸鼠获取肿瘤组织。测量瘤体重量,计算抑瘤率;免疫组化及Western blot检测瘤组织VEGF的表达。结果 其他三组较对照组均可抑制肿瘤生长,联合组较SST-14、5-Fu单纯用药组抑制作用显著(P＜0.05)。免疫组化及Western blot结果显示,与对照组相比,其他三组瘤组织VEGF表达下降(P＜0.05);其中联合组较SST-14组、5-Fu组显著下降(P＜0.05)。结论 14肽生长抑素联合5-Fu能够有效抑制不同分化程度胃癌细胞移植瘤生长,且优于单纯用药组,两药具有协同抑制作用,可能通过下调VEGF的表达,抑制肿瘤血管生成。     

MAP2K6-FP和紫杉醇对上皮性卵巢癌裸鼠移植瘤的抑制作用

目的:研究靶向融合肽MAP2K6-FP（mitogen-activated protein kinase kinase 6-fusion protein)、紫杉醇单独和两者联合对上皮性卵巢癌裸鼠移植瘤的抑制作用。方法:建立卵巢癌HO8910细胞的裸鼠皮下移植瘤模型,分为空白对照组（予生理盐水 5 ml/kg腹腔注射治疗）、MAP2K6-FP组（予0.25 mg/kg MAP2K6-FP腹腔注射治疗）、紫杉醇组（予15 mg/kg 紫杉醇腹腔注射治疗）、联合用药组（予0.25 mg/kg MAP2K6-FP+15 mg/kg 紫杉醇腹腔注射治疗）,比较4组裸鼠的移植瘤生长速度、体积、裸鼠体质量;TUNEL法、免疫组织化学法和蛋白印迹法分别检测移植瘤中细胞凋亡情况、血管内皮生长因子（vascular endothelial growth factor,VEGF）、增殖细胞核抗原（proliferating cell nuclear antigen,PCNA）的表达以及Bcl-2、Beclin 1蛋白的表达。结果:联合用药组裸鼠移植瘤体积（90 mm3）,小于MAP2K6-FP组（324 mm3）、紫杉醇组（215 mm3）和空白对照组（804 mm3）（P<0.05）。联合用药组肿瘤细胞的凋亡指数（apoptosis index,AI）(28.88±2.03)%,高于MAP2K6-FP组(14.36±0.56)%、紫杉醇组(15.78±0.87)%以及空白对照组(4.78±0.87)%（P<0.05）。联合用药组VEGF蛋白表达水平(0.14±0.06),低于MAP2K6-FP组(0.32±0.10)、紫杉醇组(0.29±0.08)及空白对照组(0.78±0.14）（P<0.01);联合用药组PCNA表达水平(18.4%),低于MAP2K6-FP组(32.3%)、紫杉醇组(29.8%)及空白对照组(81.4%）（P<0.05）。联合用药组Beclin 1/Bcl-2比例较单一用药组高(P<0.05)。结论:MAP2K6-FP联合紫杉醇能够显著抑制卵巢癌裸鼠移植瘤的生长,其机制可能与促进细胞凋亡有关。     

乏氧射线双调控的TK腺病毒载体联合放疗抑制乳腺癌裸鼠移植瘤的生长

目的观察乏氧射线双调控的TK腺病毒载体-Ad.HRE.CArG.HSV-TK联合放疗对乳腺癌细胞Bcap37裸鼠移植瘤生长的影响。方法皮下接种细胞于BALB/C(nu/nu) 裸鼠建立移植瘤模型。当肿瘤直径达8~10mm时,将裸鼠分为对照组（control）、载体组(Ad)、照射组（RT）和载体合并照射组(Ad+RT)。治疗开始为第1天,于第1、5天瘤内多点注射0.2ml表达载体,给药次日起腹腔注射GCV(40mg/kg),每日1次,连续14天。第2、4、6天给予2Gy X线照射。每3天测量肿瘤长短径,计算肿瘤体积。治疗后30天处死裸鼠,剥离瘤块称重,计算抑瘤率。对肿瘤组织行HE染色和AnnexinV法检测凋亡。结果实验组平均肿瘤体积和瘤重均显著小于对照组（P<0.05）。HE染色可见肿瘤细胞变性坏死和凋亡细胞,AnnexinV检测显示实验组凋亡率明显高于对照组（P<0.05）。结论腺病毒载体联合放疗对Bcap37裸鼠移植瘤生长具显著抑制作用并可介导凋亡,为乳腺癌进一步的放射基因治疗研究奠定了基础。     

塞来昔布对实验性结肠癌原位移植瘤生长及血管形成的影响

目的:探讨塞来昔布对实验性结肠癌原位移植瘤生长及血管形成的影响。方法:使用对数生长期的人结肠癌细胞(HT-29)于裸鼠皮下接种成瘤后原位种植。术后随机分为对照组(C组)及塞来昔布高、中、低剂量组(H、M、L组)共四组进行研究。结果:24只裸鼠实验期间无1只死亡,成瘤率为100%,比较各组原位移植瘤体积和瘤质量差异有统计学意义,P值均<0·05。L、M和H组的抑瘤率分别为25·30%、38·80%和76·92%,与对照组比较差异有统计学意义,P=0·000,且存在明显的剂量依赖。干预组瘤组织中MVD、VEGFmRNA、MMP-2mRNA和匀浆上清中PGE2含量与对照组相比差异有统计学意义,P值分别为0·050、0·050、0·050和0·010,随着剂量增加,MVD、VEGFmRNA、MMP-2mRNA和匀浆上清中PGE2含量逐渐降低。瘤组织中PGE2含量与瘤质量,以及MVD与VEGFmRNA、MMP-2mRNA均存在显著的正相关性,r=0·8814,P=0·000;r=0·8573,P=0·000;r=0·6427,P=0·001。结论:塞来昔布通过抑制人结肠癌裸鼠原位移植瘤环氧化酶-2活性,抑制PGE2合成、VEGFmRNA和MMP-2mRNA表达,抑制肿瘤的血管形成,从而对结肠癌的生长有抑制作用。     

125I粒子植入术对荷神经母细胞瘤裸鼠有效性和安全性实验研究

目的 采用动物实验方法探索 ¹²⁵I粒子植入术治疗神经母细胞瘤的有效性和安全性。方法 建立动物模型并分为 ¹²⁵I组、对照组和空白组,每组各15只。每3天测量肿瘤长、短径。每9 d计算肿瘤抑制率,检测肿瘤组织、瘤周组织凋亡、增殖蛋白表达情况,以及裸鼠内分泌指标和骨髓情况。两均数比较采用独立样本t检验。多组间分析采用单因素方差分析。结果 肿瘤抑瘤率在第9、18、27天时 ¹²⁵I组均高于对照组、空白组(P值均<0.05),对照组与空白组相近(P>0.05)。肿瘤组织Caspase-3表达 ¹²⁵I组高于对照组、空白组,PCNA表达 ¹²⁵I组低于对照组、空白组(P值均<0.05),对照组和空白组相近(P>0.05)。瘤周组织中Caspase-3、PCNA在各组间表达均相近(P值均>0.05)。肿瘤组织中凋亡细胞数 ¹²⁵I组高于空白组、对照组(P值均<0.05),空白组和对照组相近(P>0.05)。各组间内分泌指标相近(P>0.05)。¹²⁵I组中裸鼠无明显骨髓抑制现象,且与对照组和空白组相近(P值均>0.05)。结论 ¹²⁵I粒子对神经母细胞瘤有明显的杀伤作用,且在治疗剂量内也比较安全。     

蚯蚓纤溶酶对裸鼠人肝癌细胞移植瘤生长及 CD44v6表达的影响

 目的 探讨蚯蚓纤溶酶（earthworm fibrinolytic enzyme, EFE)对裸鼠人肝癌细胞移植瘤生长及CD44v6表达的影响。方法 建立肝癌SMMC-7721细胞裸鼠移植瘤模型,随机分为生理盐水组、EFE组、5-Fu组及联合用药组,计算抑瘤率及两药相互作用系数（coefficient of drug in interaction,CDI）,并行血常规检测评价EFE的副反应。同时采用免疫组化SP染色法、RT-PCR及Western blot方法观察EFE组及生理盐水组瘤组织中CD44v6的表达情况。结果 与生理盐水组相比,EFE组和5-Fu组抑瘤率分别为20.53%和23.07%;联合用药组抑瘤率为54.20%,且CDI<1。血常规检测提示EFE对造血系统无明显副反应。免疫组化和Western blot结果显示,EFE组CD44v6蛋白的表达水平较生理盐水组分别下调47.16%、28.37%（P＜0.05）。RT-PCR结果表明,EFE组CD44v6 mRNA的表达水平亦较生理盐水组低,下调16.44%（P＜0.05）。结论 蚯蚓纤溶酶对裸鼠人肝癌移植瘤的生长具有一定的抑制作用,与5-Fu存在一定的协同效应,并可以抑制黏附分子CD44v6的表达。     

JNJ-26481585对人肺腺癌培美曲塞耐药裸鼠移植瘤的抑制作用及其机制探讨

目的:探讨JNJ-26481585对人肺腺癌培美曲塞耐药裸鼠移植瘤的抑制作用及其抗癌机制。方法:构建人肺腺癌A549/培美曲塞耐药细胞(A549/PEM)的移植瘤裸鼠模型,随机分为模型组、培美曲塞组、JNJ组、联合组(培美曲塞+JNJ),第28天治疗观察结束时处死裸鼠,剥离肿瘤组织标本待测。测定4组裸鼠肿瘤体积与体质量,计算抑瘤率,观察各治疗组药物对荷瘤裸鼠的毒副反应,TUNEL方法检测4组移植瘤细胞凋亡情况的差异,qRT-PCR检测4组移植瘤细胞FAM96A、Bax、Bcl-2基因mRNA表达水平差异,Western blot检测4组移植瘤细胞FAM96A、Bax、Bcl-2蛋白表达的差异。结果:联合组的肿瘤体积、体质量低于JNJ组,JNJ组的肿瘤体积、体质量低于培美曲塞组,联合组的抑瘤率高于JNJ组,JNJ组抑瘤率高于培美曲塞组(均P<0.05)。联合组的细胞凋亡率高于JNJ组,JNJ组细胞凋亡率高于培美曲塞组(均P<0.05)。联合组肿瘤细胞的FAM96A、Bax表达水平高于JNJ组,JNJ组FAM96A、Bax表达水平高于培美曲塞组,联合组Bcl-2表达水平低于JN...     

Successful treatment with DL-alpha-difluoromethylornithine in established human small cell variant lung carcinoma implants in athymic mice

We report that p.o. administration of DL-alpha-difluoromethylornithine (DFMO), a specific inhibitor of polyamine biosynthesis, markedly inhibits the growth of established implants of cultured human small cell lung carcinoma (SCC) in athymic (nude) mice. Human SCC tumor cells, from a cell line which exhibited cell death in culture in the presence of DFMO, were inoculated s.c. into athymic mice. The tumors were permitted to grow until they became palpable (0.05 cu cm, 3- to 5-mm-diameter nodules). The animals were then randomized into control, and early (low tumor burden) and late (high tumor burden) treatment groups which received 3% DFMO in the drinking water (5.0 g/kg/day). The tumors in the untreated control group grew to a size of 29 cu cm by 9 weeks, and these animals had a median survival of 9 weeks. The late treatment group began DFMO treatment 3 weeks after clinical tumor engraftment, when mean tumor size was 1.5 cu cm (1.2- to 1.5-cm-diameter nodules). Tumor growth was inhibited by 60% (11.4 cu cm) by Week 9 and survival was prolonged, with 83% survival at 10 weeks and a 56% increase in median survival to 14 weeks (p less than 0.05). The early treatment group received the same dose of DFMO beginning 1 week after tumor engraftment, when their mean tumor size was 0.1 cu cm (4- to 6-mm-diameter nodules). The early DFMO group had a 99% inhibition in tumor growth (0.3 cu cm) (p less than 0.05). Survival was also prolonged compared to the untreated controls, with 83% survival at 10 weeks and a median survival of 15 weeks (p less than 0.05). In both the early- and late-DFMO-treatment groups, no significant clinical toxicities were observed in the first 10 weeks, during which antitumor therapeutic effects were seen. DFMO may have a potential role in the treatment of sensitive human tumors such as SCC. The data suggest that DFMO may be most useful clinically in patients with SCC who have a low tumor burden. Thus, DFMO might be an important tool to produce long-term maintenance of initial clinical remissions induced by combination chemotherapy.     

新城疫病毒D817对裸小鼠人结肠癌移植瘤的抑制作用

目的 观察新城疫病毒DK/HK/817/1980(NDV D817)对裸小鼠人结肠癌移植瘤的抑制作用.方法 采用LoVo细胞株建立裸小鼠人结肠癌移植瘤模型,分别给予裸小鼠尾静脉注射PBS、氟尿嘧啶(5-Fu)以及NDV D817高、中、低3个剂量,观察不同剂量NDV D817对移植瘤的抑制作用,病理学观察NDV D817对移植瘤和肝细胞的损伤程度,流式细胞术检测肿瘤细胞的凋亡和坏死情况,酶联免疫吸附试验(ELISA)试剂盒检测荷瘤小鼠体内肿瘤坏死因子-α(TNF-α)的含量,血凝实验检测荷瘤小鼠体内活病毒量.结果 中剂量NDV D817可明显抑制移植瘤的生长,肿瘤抑制率达48.1%.NDV D817对荷瘤小鼠体重和肝脏的损伤较小,且具有诱导肿瘤细胞凋亡和诱导机体产生TNF-α的能力.荷瘤小鼠处死后只在瘤内检测到活病毒,而在血清和其他脏器中并没有检出活病毒.结论 在对裸小鼠人结肠癌移植瘤的抑制过程中,NDV D817有明显的抑瘤效果,适当剂量的NDVD817更安全有效.     

Effects of silencing cyclooxygenase-2 expression via RNA interference on the tumorigenicity of the SMMC-7721 human hepatocarcinoma cell line

We constructed a vector carrying a shRNA sequence against cyclooxygenase-2 (COX-2) that was subsequently transfected into the human hepatocarcinoma cell line SMMC?7721. Furthermore, we established a COX-2-deficient stable cell line and a model of tumor-shRNA transplantation in nude mice. Negative shRNA was used as the control. The tumor volume in the experimental group was smaller compared to that in the control group. Hematoxylin and eosin staining indicated that the cells in the experimental group differentiated better than those in the control group. The COX-2 mRNA level in the tumor tissues injected with SMMC-7721/COX-2i was markedly downregulated compared to that in the tumor tissues injected with SMMC-7721/negative shRNA. The inhibition rate reached 68.6%. Immunohistological study showed a significantly strong COX-2 expression in the control group tumor cells, whereas the experimental group exhibited moderate expression, indicating the inhibition of COX-2 expression after transfection of cells with shRNA against COX-2. Western blot analysis further proved the inhibition of COX-2 expression. In conclusion, RNAi-mediated regulation of COX-2 expression could efficiently inhibit liver-transplanted tumor growth in BALB/c nude mice.     

Effects of alpha-difluoromethylornithine and recombinant interferon-alpha 2 on the growth of a human renal cell adenocarcinoma xenograft in nude mice

The effects of human recombinant interferon-alpha 2 (IFN-alpha 2) and alpha-difluoromethylornithine (DFMO) as single agents and in combination were studied for efficacy against the renal cell adenocarcinoma (JDF-1) in an in vitro clonogenic assay and in vivo as xenografts in nude mice. In vitro studies showed dose-dependent inhibition of JDF-1 colony formation by IFN-alpha 2. DFMO alone did not significantly inhibit colony formation even though ornithine decarboxylase activity was significantly inhibited. The combination of IFN-alpha 2 and DFMO synergistically inhibited JDF-1 colony formation. The synergism was more readily observed at low IFN-alpha 2 concentrations. In vivo studies showed a similar tumor growth inhibition pattern. JDF-1 tumors were implanted s.c. in nude mice, and drugs were administered continuously by Alza minipumps (IFN-alpha 2) and in drinking water (DFMO) for 28 days. IFN-alpha 2 alone significantly inhibited JDF-1 growth, while DFMO alone had no significant inhibitory effect. The combination of IFN-alpha 2 and DFMO inhibited tumor growth in an apparent additive manner at the doses used. This was reflected in the mean tumor weights obtained at the termination of the experiment: control, 1484 +/- 187 (S.E.) mg; DFMO only, 1106 +/- 129 mg; IFN-alpha 2 only, 941 +/- 186 mg; and DFMO plus IFN-alpha 2, 620 +/- 109 mg. Assessment of mouse natural killer cell activity at the time of sacrifice showed that DFMO inhibited natural killer cell activity, while IFN-alpha 2 had no effect. DFMO was observed to inhibit ornithine decarboxylase activity in JDF-1 tumors by 78%, IFN-alpha 2 by 18%, and the combination by 78%. In addition, the drugs individually and in combination had similar inhibitory effects on JDF-1 spermidine content. One of the unexpected findings was the alteration in the spermine:spermidine ratio in the tumors treated with the combination of DFMO and IFN-alpha 2. The ratio in this group decreased to 0.44, while ratios for control, IFN-alpha 2 only, and DFMO only were 0.99, 0.66, and 0.88, respectively. These results clearly show that combined therapy with DFMO and IFN-alpha 2 is more effective than is single-drug therapy. The mechanism by which these drugs coordinately inhibit tumor growth is unclear but appears to be associated with direct inhibition of tumor cell proliferation, possibly by modulation of polyamine metabolism.     

重楼醇提取物抑制胃癌SGC-7901裸鼠移植瘤细胞增殖的研究

[目的]探讨重楼醇提取物对裸鼠移植瘤胃癌细胞增殖的影响。[方法]培养人胃癌SGC-7901细胞并建立荷瘤鼠胃癌模型,实验分为空白组、不同浓度（12.5、25、50mg/kg）重楼醇提取物用药组、化疗组（5-Fu）及联合组（5-Fu＋重楼）,观测荷瘤鼠移植瘤体积改变,并用免疫组化方法检测PDGF-B蛋白的表达。[结果]重楼醇提取物对荷瘤鼠胃癌移植瘤的生长有明显的抑制作用,各用药组移植瘤体积增长幅度明显小于空白组（P〈0.05）。各用药组移植瘤重量与空白组比较,差异均有显著性（P〈0.05）;各组瘤重明显大于联合组（P〈0.01）,提示5-Fu与重楼联合抑制作用更显著。各用药组PDGF-B蛋白染色的细胞明显减少,表达率较空白组显著降低（P〈0.05）。[结论]重楼醇提取物可明显抑制裸鼠胃癌移植瘤的生长,与5-Fu联合应用具有协同作用,其机制可能是通过抑制肿瘤细胞PDGF-B蛋白的表达。