蜂毒素对人肝癌BEL-7402细胞裸鼠皮下移植瘤生长及肿瘤血管生成的影响

背景与目的:蜂毒素体外抗骨肉瘤、白血病及宫颈癌的研究已有报道.我们先前的实验发现蜂毒素能够抑制人肝癌细胞株BEL-7402细胞增殖,并诱导其凋亡.本研究拟探讨蜂毒素在裸小鼠体内的抗肝癌作用及其对肿瘤血管生成的影响.方法:建立人肝癌BEL-7402细胞裸鼠皮下移植瘤模型,随机分为5组:生理盐水对照组(10 ml/kg)、阳性对照组(沙利度胺,200 mg/kg)、蜂毒素低剂量组(40 μg/kg)、蜂毒素中剂量组(60 μg/kg)和蜂毒素高剂量组(80 μg/kg).测量各组裸鼠肿瘤体积,观察蜂毒素的体内抗肿瘤作用.光镜下观察肿瘤组织及瘤内血管形态.采用免疫组织化学SABC法检测微血管密度(microvessel density,MVD)及血管内皮细胞生长因子(vascular endothelial growth factor,VEGF)、碱性成纤维细胞生长因子(basic fibroblast growth factor,bFGF)和核转录因子κB(nuclear factor κB,NF-κB)蛋白表达.应用实时荧光定量PCR法检测BEL-7402细胞VEGF mRNA和bFGF mRNA的表达.结果:蜂毒素低、中、高剂量组裸鼠肿瘤相对体积(V/V0)分别为4.42±0.58、3.47±0.97和3.06±1.23,与生理盐水对照组(V/V0为9.06±1.45)相比,蜂毒素处理组肿瘤体积明显缩小(P＜0.01).与生理盐水对照组MVD(16.50±2.35)比较,蜂毒素低、中、高剂量组肿瘤组织MVD(11.33±1.86、9.17±1.17和6.67±1.21)明显降低(P＜0.01).显微镜下可见蜂毒素各剂量组肿瘤组织呈片状坏死,肿瘤间质内可见肿瘤血管,并有血管破坏现象.蜂毒素低、中、高剂量组肿瘤组织VEGF(2.59±0.27、2.61±0.17和1.55±0.22)、bFGF(2.45±0.78、2.27±0.36和2.10±0.27)及NF-κB(2.79±0.29、2.71±0.66和2.26±0.56)阳性表达指数均低于生理盐水对照组(3.80±0.60、4.43±0.34和4.98±0.63)(P＜0.01).实时荧光定量PCR检测显示,蜂毒素能够抑制BEL-7402细胞VEGF mRNA和bFGF mRNA的表达.结论:蜂毒素能够明显抑制人肝癌BEL-7402细胞裸鼠移植瘤的生长,影响NF-κB表达、下调VEGF和bFGF的表达、抑制肝癌血管生成可能是其抗肿瘤作用的重要机理之一.     

二烯丙基二硫对人胃癌细胞裸鼠移植瘤的抗肿瘤作用

背景与目的:既往研究发现二烯丙基二硫(diallyldisulfide,DADS)在体外可抑制多种肿瘤细胞生长,但在体内抗肿瘤作用的研究报道较少。本实验旨在探讨DADS对人胃癌细胞移植瘤在BALB/C裸鼠体内生长的影响。方法:未经药物处理和经30mg/LDADS处理1天的胃癌细胞MGC803接种于裸鼠皮下;观察体外DADS处理MGC803细胞裸鼠移植瘤的成瘤情况和未处理MGC803细胞移植瘤成瘤后腹腔注射DADS对胃癌移植瘤在BALB/c裸鼠体内生长情况的影响。Westernblot检测瘤组织中增殖细胞核抗原(proliferatingcellnuclearantigen,PCNA)的表达情况。结果:30mg/LDADS处理的MGC803细胞移植裸鼠体内无一成瘤。荷瘤裸鼠腹腔注射DADS剂量为50、100和200mg/kg时的抑瘤率分别为27.8%、66.1%和73.0%,同时可抑制移植瘤癌细胞PCNA的表达。结论:DADS可明显降低胃癌细胞裸鼠移植瘤的成瘤性,并对移植瘤生长有明显抑制作用。     

蜂毒素对人肝癌裸鼠移植瘤的抗血管生成作用

目的探讨蜂毒素对人肝癌裸鼠移植瘤生长的影响及其抗血管生成作用。方法建立人肝癌裸鼠皮下移植瘤模型,观察蜂毒素对肿瘤生长的影响。采用免疫组织化学法,检测肿瘤组织微血管密度（microvessel density,MVD）及碱性成纤维细胞生长因子（basic fibroblast growth factor,bFGF）、缺氧诱导因子-1α（hypoxia inducible factor-1α,HIF-1α）和核转录因子κB（nuclear factorκB,NF-κB）的水平。结果蜂毒素低、中、高剂量组相对肿瘤增殖率分别为48.78%、38.33%和33.82%。与生理盐水组比较,蜂毒素处理组肿瘤体积明显缩小（P〈0.01）。免疫组化结果显示,蜂毒素可降低肿瘤组织MVD,且蜂毒素处理组bFGF、HIF-1α和NF-κB蛋白水平明显低于生理盐水组（P〈0.01）。结论蜂毒素可抑制裸鼠皮下移植瘤的生长,其作用机制可能是降低NF-κB活性,抑制HIF-1α转录,进而下调bFGF表达,最终阻碍肝癌血管生成。     

大黄素抑制人肝癌HepG2细胞血管生成作用及其机制研究

目的 大黄素可促进人肝癌HepG2细胞的凋亡,然而其是否可抑制肝细胞癌(hepatocellular carcinoma,HCC)血管生成及其机制罕见报道.本研究探讨大黄素对人肝癌HepG2细胞血管生成以及缺氧诱导因子-1α (hypoxia inducible factor-1a,HIF-1d)和血管内皮生长因子(vascular endothelial growth factor,VEGF)的影响,以及大黄素体内抗肝癌机制.方法 采用体内鸡胚绒毛尿囊膜(chick chorioallantoic membrane,CAM)实验,实验随机分为阴性对照组(生理盐水)、大黄素低剂量组(10 μmol/L)、大黄素高剂量(20 μmol/L)和阳性对照组(0.15 mg/mL地塞米松),每组各10只,每24 h每组追加同样等量药物,共72 h,观察大黄素对CAM血管生成的抑制作用.体外培养HepG2细胞,以氯化钴(CoCl2)模拟化学缺氧,设立缺氧未处理组[阴性对照组(生理盐水)]、缺氧大黄素低剂量组(10 μmol/L)、缺氧大黄素高剂量组(20 μmol/L)和缺氧阳性对照组[10 μmol/L 5-氟尿嘧啶(5-fluorouracil,5-FU)],每组设6个复孔,处理24 h.采用小管形成实验,观察大黄素对HepG2细胞相对小管数目的影响,免疫细胞化学分析检测HIF-1α和VEGF阳性细胞的表达,Real-Time PCR分析检测HIF-1α mRNA和VEGF mRNA的表达.采用Graphpad 5.0软件进行描述性统计,组间比较采用one-way-ANOWA和Bonferroni检验.结果 CAM实验显示,实验组新生血管数目明显减少,与阴性照组比较,差异有统计学意义,F=13.374,P=0.002.阴性对照组新生血管数目为(31.47±1.81)个.给药后CAM血管生成减少,大黄素低剂量组、高剂量组和地塞米松组分别为(19.48±0.66)、(10.33±1.04)和(9.89±0.57)个,与阴性对照组比较,差异有统计学意义,P值分别为0.041、0.004和0.003;大黄素低剂量组和高剂量组与地塞米松组比较,差异无统计学意义,P值分别为0.539和1.000.小管形成实验显示,实验组相对小管数目明显减少,与阴性照组比较,差异有统计学意义,F=21.529,P＜0.001.阴性对照组相对小管数目为(100.00±0.00)％.给药后,相对小管数目明显减少,大黄素低剂量、高剂量组和阳性对照组分别为(65.85±12.67)％、(46.94±8.34)％和(41.77±7.53)％,与阴性对照组比较,差异有统计学意义,P值分别为0.049、0.001和＜0.001;大黄素低剂量组和高级剂量组与阳性对照组比较,差异无统计学意义,P值分别为0.104和0.069.免疫细胞化学分析显示,大黄素低剂量组、高剂量组和阳性对照组HIF-1α和VEGF阳性细胞显著减少.Real-Time PCR分析显示,实验组HIF-1α mRNA和VEGF mRNA表达降低,与阴性照组比较,差异有统计学意义(F=31.908,P＜0.001;F=25.146,P＜0.001).阴性对照组HepG2细胞HIF-1α mRNA和VEGF mRNA相对表达分别为0.92±0.15和0.95±0.15;大黄素低剂量组HIF-1α mRNA和VEGF mRNA相对表达分别为0.45±0.07和0.51±0.08,与阴性对照组比较,差异有统计学意义,P值分别为0.021和0.013;大黄素高剂量组HIF-1α mRNA和VEGF mRNA相对表达分别为0.32±0.05和0.40±0.07,与阴性对照组比较,差异有统计学意义,P值分别为＜0.001和0.001;阳性对照组HIF-1α mRNA和VEGF mRNA相对表达分别为0.30±0.04和0.34±0.05,与阴性对照组比较,差异有统计学意义,P值均＜0.001;大黄素低剂量组、高剂量组HIF-1α mRNA和VEGF mRNA相对表达与阳性对照组比较,差异无统计学意义,P值分别为0.663、0.362、0.443和1.000.结论 大黄素可能通过抑制HIF-1d mRNA的表达,从而降低VEGF mRNA的表达来抑制HepG2细胞新生血管的形成.     

蜂毒素抗骨肉瘤裸鼠移植瘤的作用及对肿瘤血管生成拟态的影响

目的：探讨蜂毒素抗裸鼠骨肉瘤的作用及对肿瘤血管生成拟态的影响。方法：体外建立matrigel胶三维培养系统，观察蜂毒素对骨肉瘤UMR-106细胞血管生成拟态（vasculogenic mimicry，VM）形成的影响；建立裸鼠骨肉瘤胫骨移植瘤模型，分为0．9％氯化钠溶液组、蜂毒素组（320ug／kg）、顺铂组（2n,g／kg），瘤内注射给药10d，观察小鼠的肿瘤抑制率和瘤体质量抑制率；用CD34与PAS双重染色观察骨肉瘤VM密度；免疫组织化学法和Western印迹法检测肿瘤组织中缺氧诱导因子1α（hypoxia inducible factor-1α，HIF—1α）、基质金属蛋白酶-2（matrix metalloproteinase-2，MMP-2）蛋白的表达。结果：蜂毒素在体外可以破坏骨肉瘤细胞的血管状结构；体内对骨肉瘤的瘤体质量抑制率为38．92％，体积抑制率为43．04％。蜂毒素组VM密度、HIF-1α、MMP-2蛋白的表达水平均明显低于0．9％氯化钠溶液组（P〈0．01）。结论：蜂毒素能明显抑制UMR-106骨肉瘤裸鼠移植瘤的生长，其机制可能与下调HIF-1α、MMP-2蛋白的表达、抑制骨肉瘤VM有关。     

Avastin对胃癌裸鼠原位移植模型血管生成的影响

背景与目的:血管内皮生长因子(vascularendothelialgrowthfactor,VEGF)和肿瘤的生长和转移密切相关,本实验通过VEGF单克隆抗体Avastin联合或不联合氟尿嘧啶(5-fluorouracil,5-FU),对人类胃癌裸鼠原位种植模型的肿瘤生长和转移进行干预治疗,从而探讨Avastin对胃癌生长、转移和血管生成的抑制作用。方法:应用原位移植方法建立裸鼠胃癌转移模型,术后10天将裸鼠随机分为4组:对照组、5-FU单药组、Avastin单药组和联合用药组。经过6周的治疗,对裸鼠原位肿瘤的瘤重、抑瘤率、肿瘤微血管密度、凋亡指数以及肝脏转移灶进行检测和分析。结果:和对照组相比,5-FU单药组、Avastin单药组和联合用药组原位移植肿瘤重量明显降低,抑瘤率分别为37.52%,58.76%和98.51%。微血管密度Avastin单药组和联合用药组均比对照组明显减少(8.40±1.26和7.20±1.23vs15.30±1.06),而5-FU组与对照组之间没有显著的差别;Avastin单药组和联合用药组的凋亡指数比对照组明显升高[(11.50±1.58)%和(13.60±1.35)%vs(4.70±1.70)%]。联合应用Avastin和5-FU对肝脏转移灶具有明显的抑制作用,而其他3组的抑制肝转移效果没有明显的差别。结论:抗VEGF抗体Avastin通过抑制肿瘤新生血管的生成而诱导胃癌细胞凋亡,进而显著抑制裸鼠原位肿瘤的生长。联合应用Avastin和5-FU不仅对原位肿瘤的生长抑制最为明显,而且对肝脏转移有显著的抑制作用。因此,联合应用Avastin和传统的细胞毒化疗药物对胃癌的治疗效果更显著。     

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。     

半枝莲抑制肿瘤血管生成的作用及其机制研究

背景与目的:以血管再生作为靶点的诸多化学合成药物在有效抑制血管生成的同时具有不可抵抗的副作用,近年来国内外都在致力于从天然药物中开发肿瘤血管生成阻断剂。作为传统抗癌有效药物半枝莲,其阻断血管生成的作用研究少见报道。本实验拟探讨其对肿瘤血管生成的抑制作用及其可能的机制。方法:采用Matrigel栓、原代人脐静脉内皮细胞(humanumbilicalvascularendotheialcell,HUVEC)建立体内外血管生成模型,观察半枝莲对血管生成的影响;通过Transwell小室趋化实验检测半枝莲对宫颈癌细胞HeLa培养上清诱导内皮细胞迁移能力的影响;采用酶联免疫吸附法(enzyme-linkedimmunosorbentassay,ELISA)检测半枝莲对HeLa细胞血管内皮细胞生长因子(vascularendothelialgrowthfactor,VEGF)蛋白水平的影响。结果:半枝莲能明显抑制Matrigel栓内微血管的形成;体外小管形成实验发现,20%、40%半枝莲含药血清组小管形成数为(5.6±1.1)、(1.0±0.7),与同浓度空白血清组(9.8±1.3和13.4±1.1)相比有显著性差异(P值分别为0.001、0.000)。经20%、40%半枝莲含药血清处理后内皮细胞迁移数分别为(19.75±2.63)、(14.00±2.58),明显少于同浓度空白血清组(24.25±2.06和26.50±4.65)(P值分别为0.038、0.006)。40%含药血清作用24、48h后HeLa细胞VEGF表达量分别为(138.67±9.50)、(93.84±41.11),与空白血清组(195.82±2.43和193.68±18.37)相比具有显著性差异(P值分别为0.006、0.036)。结论:半枝莲能有效抑制肿瘤血管生成,其机制可能与阻断内皮细胞迁移、下调VEGF蛋白表达有关。     

沉默SIAH2基因抑制人肝癌细胞HepG2裸鼠移植瘤生长实验研究

目的 本研究前期实验发现,靶向SIAH2的shRNA载体能显著抑制HepG2细胞SIAH2 mRNA和蛋白的表达,并抑制细胞体外增殖.本研究从体内水平验证靶向SIAH2的干扰载体对人肝癌细胞HepG2细胞裸鼠移植瘤生长的抑制作用.方法 转染pGenesil-SIAH2的HepG2细胞作为实验组,命名为HepG2-SIAH2;转染空载体pGenesil-1的HepG2细胞作为阴性对照组,命名为HepG2-neo;未转染任何质粒的HepG2细胞作为空白对照组,通过G418筛选出稳定转染细胞株.将15只裸鼠随机分为3组,接种肿瘤细胞后观察裸鼠成瘤情况.4周后测量肿瘤的体积和瘤体质量,绘制移植瘤生长曲线,并用实时荧光定量PCR和蛋白质印迹法检测移植瘤中SIAH2的表达情况.结果 稳定转染pGenesil-SIAH2的细胞株构建成功,3组裸鼠接种癌细胞后均有肿瘤形成.与空白对照组和阴性对照组相比,实验组肿瘤生长速度明显减慢,实验组平均瘤体积(261.57±41.141)mm3,明显低于阴性对照组(494.35±93.236) mm3(P=0.015)和空白对照组(418.3±28.576 5)mm3(P=0.012),差异有统计学意义;实验组平均瘤体质量为(0.162±0.02)g,明显低于阴性对照组(0.358±0.12)g(P=0.032)和空白对照组(0.322±0.24)g(P=0.028).实验组瘤体内SIAH2 mRNA相对表达量为0.83±0.35,明显低于阴性对照组2.35±0.96(P=0.003)和空白对照组2.57±0.41(P=0.006),差异有统计学意义.实验组瘤体内SIAH2蛋白表达量为0.72±0.02,明显低于阴性对照组2.61±0.67(P=0.004)和空白对照组2.49±0.91(P=0.007),差异有统计学意义.结论 靶向SIAH2的shRNA干扰载体能有效抑制人肝癌裸鼠移植瘤的生长,SIAH2有可能成为肝癌基因治疗新的分子靶.     

环氧合酶-2抑制剂塞来昔布对人肝癌HepG2裸小鼠移植瘤生长和肿瘤血管生成的抑制作用

背景与目的:有研究证实,环氧合酶-2(cyclooxygenase-2,COX-2)与肿瘤,特别是与消化系统肿瘤形成的关系较为密切,而其抑制剂则具有抗肿瘤作用。本研究探讨特异性抑制剂塞来昔布对人肝癌HepG2裸小鼠移植瘤生长和肿瘤血管生成的抑制作用。方法:将肝癌细胞HepG2种植至裸鼠背侧皮下,4天后开始用塞来昔布治疗,58天后处死。观测裸鼠移植瘤的体积和质量。并采用免疫组化和逆转录-聚合酶链反应法(RT-PCR)检测裸鼠移植瘤组织中COX-2、血管内皮生长因子(vascularendothelialgrowthfactor,VEGF)、碱性成纤维生长因子(basicfibroblastgrowthfactor,bFGF)和血管生成素-2(angiopoientin-2,Ang-2)的表达,用免疫组化法检测微血管密度(microvesseldensity,MVD)。结果:治疗组切除的移植瘤平均体积和质量分别是(709.11±108.53)mm3和(2.63±0.34)g,对照组分别为(1417.55±69.50)mm3和(5.32±0.98)g,两组比较差异有显著性(P<0.01)。治疗组肿瘤增殖率为55.21%。②对照组COX-2、VEGF、bFGF、Ang-2的表达和MVD值分别是4.50±0.25、5.43±0.58、4.03±0.47、5.53±0.54和128.24±9.82,而在塞来昔布组分别是2.42±0.29、2.80±0.30、2.23±0.41、2.88±0.25和29.23±1.52。两组相比较,COX-2、VEGF、bFGF、Ang-2的表达和MVD值差异有显著性(P<0.01)。COX-2与VEGF、bFGF、Ang-2和MVD有明显的相关性(r分别为0.862、0.882、0.857,P分别<0.01)。结论:塞来昔布有效抑制了人肝癌细胞HepG2裸小鼠移植瘤的生长和血管生成,其作用途径是抑制了COX-2的表达。     

Iressa对肝癌细胞Hep-3B、HepG2裸鼠移植瘤的抑制作用

背景与目的：Iressa是一种新型分子靶向药物,在治疗晚期非小细胞肺癌中显示出较好疗效,对Iressa治疗肝癌的研究国内外报道较少。本研究旨在探讨Iressa对肝癌Hep-3B、HepG2细胞裸鼠移植瘤的抑制作用及其毒副作用。方法：肝癌Hep-3B、HepG2细胞移植瘤裸鼠随机分为对照组、低剂量组和高剂量组,分别用葡萄糖溶液、Iressa 100mg／kg和Iressa 200mg／kg每日一次灌胃,每周灌五天,连用3周,用药结束后2天处死动物。分别计算Iressa对两种肝癌的抑瘤率,比较各组裸鼠肿瘤大小、体重及脾指数。结果：给药前各组裸鼠体重和肿瘤体积无差异。低剂量组和高剂量组Iressa对Hep-3B肝癌移植瘤的抑瘤率分别为32．77％、46．99％;低剂量组和高剂量组Iressa对HepG2肝癌移植瘤的抑瘤率分别为68．57％、75．24％。两种肿瘤类型的高剂量组裸鼠的脾指数和体重下降与对照组比较均有显著性差异,低剂量组和对照组裸鼠的脾指数和体重比较无明显差异。结论：Iressa对肝癌Hep-3B、HepG2细胞移植瘤生长均有明显抑制作用。但高剂量可能引起裸鼠体重下降并影响免疫器官功能。     

Antitumor effect of trimelamol against human breast carcinoma xenografts in nude mice

The antitumor effect of N-2, N-4, N-6-trihydroxymethyl-N-2, N-4, N-6-trimethylmelamine (trimelamol), a synthetic analogue of hexamethylmelamine, was investigated using human breast carcinoma xenografts in nude mice. Four tumor models, T-61, Br-10, R-27 and MCF-7 were estrogen receptor (ER)-positive and their growth was estradiol-dependent. The MX-1 model was ER-negative and grew estradiol-independently. Sixty mg of trimelamol per kg dissolved in 5% dimethylsulphoxide (DMSO) with 5% glucose was administered intraperitoneally for 5 days weekly for three weeks. Trimelamol showed potent antitumor activity on T-61 and MX-1 in a dose-responsive manner with a marginal effect on Br-10, whilst R-27 and MCF-7 were insensitive to this agent. This antitumor spectrum on human breast carcinoma xenografts was similar to that of hexamethylmelamine previously reported using the same xenograft models. Trimelamol is water-soluble and does not require metabolic activation which is needed for hexamethylmelamine. These advantages allow the paraenteral administration of trimelamol, and warrant the further investigation of this drug for breast carcinomas.     

Antitumoral effects of vasoactive intestinal peptide in human renal cell carcinoma xenografts in athymic nude mice

We studied antitumor effect of VIP in human renal cell carcinoma (RCC) (A498 cells xenografted in immunosuppressed mice). VIP-treated cells gave resulted in p53 upregulation and decreased nuclear β-catenin translocation and NFκB expression, MMP-2 and MMP-9 activities, VEGF levels and CD-34 expression. VIP led to a more differentiated tubular organization in tumours and less metastatic areas. Thus, VIP inhibits growth of A498-cell tumours acting on the major issues involved in RCC progression such as cell proliferation, microenvironment remodelling, tumour invasion, angiogenesis and metastatic ability. These antitumoral effects of VIP offer new therapeutical possibilities in RCC treatment.     

重组人肿瘤坏死因子对裸鼠移植人肝癌的抑制作用

采用裸鼠移植人肝癌模型，观察ｒｈＴＮＦ对肝癌细胞的抑制作用，结果发现ｒｈＴＮＦ瘤内注射或腹腔注射对肝癌细胞均有抑制作用。高剂量和中剂量组对肿瘤体积的抑制率分别为３３．４％和２５．１％，１００００／只剂量的ｒｈＴＮＦ腹腔注射其抑制率为３１．６；瘤体重量的抑制在高剂量组、中剂量组和腹腔组分别为３９，３３％２９．７％。     

Antitumor effects of artesunate on human breast carcinoma MCF-7 cells and IGF-IR expression in nude mice xenografts

Purpose： The objective of this study was to investigate the anti-tumor effects and analyze the mechanism of artesunate （ART） action on breast cancer in vivo using tumor transplanted nude mice. Methods： The human breast tumor cell line MCF-7 was transplanted into nude mice, and the animals were treated with various doses of ART alone or in combination with cyclophosphamide （CTX） or normal saline （NS）. The tumor inhibitory effects were observed and compared, and the ultrastructural morphology of the transplanted tumor cells was observed by electron microscopy. The apoptosis rates and cell cycle status were detected by flow cytometry （FCM）. The expression of apoptosis-related proteins p53, Bcl-2, Bax and Caspase-3 were detected by immunohistochemistry and IGF-IR was detected by western blot. The expression correlation for these proteins was also analyzed. Results： The tumor inhibition rates in the low dose ART group, high dose ART group, CTX group and combined drug therapy group were （24.39±10.20）%, （40.24±7.02）%, （57.01±5.84）% and （68.29±5.1）%, respectively. The cell cycle was arrested in phase G0/Gt after treatment with ART. The expression of Bcl-2 was significantly reduced, and the expression levels of Bax and Caspase-3 were significantly increased in the ART group compared to the negative control saline group. There was no significant difference detected in p53 expression. The Bcl-2 level was negatively related to Bax and Caspase-3. The western blotting results showed IGF-IR downregulation. Conclusions： ART inhibits the growth of MCF-7 breast tumor cell xenografts in nude mice. The anti-tumor mechanism of ART for human breast carcinoma in nude mice might be correlated with the alteration of apoptosis related protein expression, which may further induce apoptosis and inhibit cell proliferation.     

Antitumor effect of deferoxamine on human hepatocellular carcinoma growing in athymic nude mice.

BACKGROUND. Iron is essential for the growth of all living cells. One of the important intracellular roles for iron is in the activation of ribonucleotide reductase, the enzyme that catalyzes the first step in DNA synthesis. Thus, the intracellular iron level may serve as a regulator of cell growth. The authors tested the hypothesis that lowering body iron concentration inhibits the growth of human-derived hepatocellular carcinoma (HCC) cells by depleting these cells of iron. Deferoxamine (DFO), an iron-chelating agent, was used to lower intracellular iron level. METHODS. HCC cells, PLC/PRF/5 (7 x 10(6) cells/mouse), were transplanted subcutaneously into athymic nude mice. When tumors reached 200-300 microliters in size, mice with comparable tumor sizes were paired; one was treated with DFO (300 mg/kg body weight/day, 5 days/week) intraperitoneally while the other received no treatment. RESULTS. Eight pairs of mice with HCC were observed for 5-18 weeks. Mean tumor growth rates (TGR) (mean +/- standard error) for the untreated and treated mice were 30.5 +/- 3.7 microliters/week and 11.9 +/- 1.5 microliters/week. The difference was significant (P < 0.02). In the second set of studies, DFO treatment was begun when the tumor size was smaller (100-200 microliters). Four pairs of mice were observed for 4-15 weeks; mean TGR for the four untreated mice was 18.1 +/- 5.1 microliters/week. In two mice treated with DFO, tumors regressed completely by the seventh week after initiation of treatment. The two remaining mice on DFO therapy had much slower growing tumors, with a mean TGR of 1.8 +/- 0.5 microliters/week. CONCLUSIONS. Thus, our results suggest that (1) reduction of intracellular iron concentration by DFO may be useful as antitumor therapy in HCC and (2) the favorable effects of DFO treatment are best seen when treatment is begun when the tumor is small.     

含CpG寡核苷酸在人神经母细胞瘤裸鼠移植瘤模型中的抗肿瘤效应

背景与目的：含有非甲基化CpG二核苷酸的寡脱氧核苷酸（CpG oligonucleotides,CpGODN）序列可以模拟细菌DNA特征,作为“异己信号”刺激机体免疫系统,发挥抗肿瘤作用。本研究探讨在人神经母细胞瘤（neuroblastoma,NB）裸鼠移植瘤模型中,CpGODN是否可以通过调节非特异性免疫来介导抗肿瘤效应。方法：体外WST-1实验明确CpGODN对神经母细胞瘤细胞株SK—N—MC的生长影响,建立NB荷瘤动物模型,当肿瘤生长到皮下可触及时,随机分组后给予不同注射处理（生理盐水、non—CpGODN、CpGODN）、观察各组小鼠肿瘤生长情况,病理组织学方法检测各组肿瘤组织的异同,免疫荧光组化法检测自然杀伤细胞（natural kill cell,NK）和巨噬细胞的浸润。结果：体外实验证明CpGODN对SK—N—MC细胞无明显的直接细胞毒性及生长抑制作用。CpGODN处理组与non—CpGODN、生理盐水组相比,肿瘤细胞生长明显受到抑制[（0．14±0．03）cm^3vs．（2．97±0．40）cm^3、（3．80±1．12）cm^3,（P〈0．01）]。HE染色显示与肿瘤细胞生长活跃的对照组相比,CpGODN处理组肿瘤组织中有较多的炎性细胞浸润及大片坏死灶。免疫荧光染色发现CpGODN处理组与生理盐水组、non—CpGODN组相比较瘤体内有明显的NK、巨噬细胞浸润。结论：具有免疫刺激作用的CpGODN可能通过调节NK、巨噬细胞的活性来抑制NB生长,发挥抗肿瘤作用。     

Antitumor and anti-metastatic effects of cyclooxygenase-2 inhibition by celecoxib on human colorectal carcinoma xenografts in nude mouse rectum

We examined the effects of the preferential cyclooxygenase-2 (COX-2) inhibitor celecoxib on tumorigenesis, angiogenesis, apoptosis, vascular endothelial growth factor (VEGF) protein expression and metastasis in HT-29 human colorectal carcinoma cell xenografts in nude mouse rectum. COX-2 mRNA expression was examined in the xenograft and metastatic sites. The antitumor effect of celecoxib in the xenografts was evaluated by measuring the weight of the peri-ano-rectal tumor. The anti-metastatic effect of celecoxib was assessed by quantification of lymph node and lung metastases by amplification of a cancer-related human DNA by TaqMan PCR. The effects of celecoxib on angiogenesis, apoptosis, prostaglandin E2 (PGE2) production and VEGF protein expression in the xenografts were evaluated by means of microvessel density (MVD) counting, terminal deoxynucleotidyl transferase-mediated nick end labeling assay, quantitative enzyme-linked immunosorbent assay and western blotting, respectively. The rectal xenograft model showed lymph node and lung metastases with enhanced expression of COX-2 mRNA in each organ. Celecoxib inhibited rectal xenograft growth in a dose-dependent manner as follows: 150?ppm, 33.0% (p=0.000220); 750?ppm, 46.4% (p=0.0000292); 1500?ppm, 63.4% (p=0.0000109). Celecoxib inhibited lymph node metastasis in a dose-dependent manner as follows: 150?ppm, 86.7% (p=0.0263); 750?ppm, 90.3% (p=0.00638); 1500?ppm, 96.0% (p=0.000894). Celecoxib also inhibited lung metastasis as follows: 750?ppm, 53.3% (p=0.0107); 1500?ppm, 78.3% (p=0.00022). Celecoxib (1500?ppm) significantly inhibited PGE2 production by 68.4% (p=0.000157) and MVD counting by 48.2% (p=1.3x10-12) and induced apoptosis 2.5-fold (p=3.0x10-14) in the rectal xenograft. Celecoxib suppressed VEGF protein expression in the rectal xenograft. These studies demonstrate that celecoxib reduces the growth and metastatic potential of colorectal carcinoma in mice through COX-2 inhibition, anti-angiogenesis and apoptosis induction. The studies using HT-29 human colorectal carcinoma cell xenografts in nude mouse rectum also provide important information that supports that the COX-2 inhibitor celecoxib has a high potential for use as a clinical agent for inhibition of hematological and lymphatic metastases of colorectal cancer.     

奥曲肽致裸鼠肝癌原位移植瘤坏死的实验研究

背景与目的：生长抑素类似物奥曲肽可抑制肝癌的生长,但能否使其坏死、获得更好的抗肿瘤效果呢？本研究旨在观察奥曲肽在体内、外对肝癌细胞株HepG2的作用,探讨其致肿瘤坏死的机制。方法：采用四甲基偶氮唑蓝法检测体外HepG2细胞的增殖,建立裸鼠肝癌HepG2细胞原位移植瘤模型．奥曲肽组裸鼠皮下注射奥曲肽100μg／（kg·d）;对照组皮下注射相同体积的生理盐水,连续用药8周。组织学评估肿瘤坏死程度,免疫组化检测移植瘤中血管内皮生长因子（VEGF）的表达,Western blot和免疫组化检测生长抑素受体2（SSTR2）的表达。结果：奥曲肽（0．1—1000nmol/L）作用24h,不影响HepG2细胞增殖。奥曲肽组裸鼠肝癌移植瘤重[（7．15±2．96）g]高于对照组[（4．21±3．11）g],移植瘤坏死体积[（81．86％±0．05）％]大于对照组[（43．75±0．06）％],两组相比差异均有统计学意义（P〈0．05）。与对照组明显不同的是．奥曲肽组移植瘤中未见VEGF表达。两组移植瘤组织血窦中SSTR2表达无显著性差异（P〉0．05）。结论：在肝癌细胞活跃增殖条件下,奥曲肽通过移植瘤血窦中SSTR2介导,仅仅抑制肿瘤血管生成,可致裸鼠肝癌显著坏死的良好效应。