ACHN人肾癌裸鼠移植瘤模型的生物学特性及放射治疗观察

目的观察ACHN人肾癌裸鼠皮下移植瘤模型的生物学特性及其对放射线的敏感性。方法分别利用瘤细胞悬液接种法、瘤块包埋法获得ACHN人肾癌裸鼠移植瘤模型，观察移植瘤的生长情况、成瘤率、肝肺转移率及病理形态。ACHN皮下荷瘤鼠14只，随机分为空白对照组和放疗组，6MV X直线加速器对放疗组移植瘤局部单次照射12Gy，观察裸鼠的耐受性及肿瘤生长抑制情况；透射电镜观察瘤细胞超微结构变化。结果瘤块包埋法成瘤稳定，成瘤率92．5%，肝转移率43％，未见肺转移。裸鼠对12Gy射线局部照射耐受良好，放疗组移植瘤与空白对照组比较生长明显受抑制（P〈0．01）；放疗组瘤细胞凋亡现象明显。结论ACHN人肾癌裸鼠移植瘤模型可作为肾癌放疗实验研究的有效工具。     

纳米磁小体靶向药囊治疗人胆管癌细胞株移植瘤实验研究

目的:将纳米磁小体靶向药囊(TM5-FUNC)经尾静脉注射入胆管癌荷瘤裸鼠体内,通过埋植在移植瘤内的磁化支架所产生的磁靶向引导作用,TM5-FUNC选择性地聚集于裸鼠胆管癌移植瘤组织内;探讨此装置对人胆管癌的生长抑制作用。方法:建立人胆管癌裸鼠移植瘤模型,将裸鼠随机分成6组,通过尾静脉按分组方案给药,分别将TM5-FUNC 250mg/kg、200mg/kg和150mg/kg组列为高、中、低剂量组。计算各组裸鼠肿瘤体积、抑瘤率和肿瘤生长曲线。处死裸鼠后,将肿瘤标本置电镜下观察肿瘤组织超微结构改变情况。结果:结合内置支架的TM5-FUNC高、中剂量组的移植肿瘤体积在治疗后35d与对照组比较有显著差异(P<0.05);TM5-FUNC低剂量组的肿瘤体积与对照组比较则无明显差异(P>0.05)。其肿瘤的抑制率分别为:高剂量组39.6%、中剂量组14.6%、低剂量组7.9%。从高、中、低剂量TM5-FUNC干预组中可见,随着药物浓度的增高,肿瘤生长越缓,高剂量组肿瘤生长曲线变化最为缓慢,中剂量组次之,其余组曲线变化较为一致。电镜结果显示,TM5-FUNC对荷瘤裸鼠的肿瘤细胞有诱导凋亡作用,且随着药物浓度的增大,细胞凋亡的形态改变越为明显。结论:本课题组所研制的TM5-FUNC新剂型,在内磁场的导向作用下,能有效抑制人胆管癌裸鼠移植瘤的生长。     

AdKDR-CDglyTK融合基因系统治疗胰腺癌的实验研究

目的 观察腺病毒介导的KDR启动子驱动的CD/TK融合双自杀基因系统(以下简称为AdKDR-CDglyTK)对胰腺癌的治疗作用.方法 采用培养细胞移植法,将人胰腺癌细胞系Capan-2接种于裸鼠背部皮下,建立裸鼠人胰腺癌移植瘤模型.将20只裸鼠随机分为4组,每组5只.分组方法:Ⅰ组:注射重组腺病毒AdKDR-CDglyTK与前药5-FC与GCV;Ⅱ组:仅注射前药5-FC与GCV;Ⅲ组:仅注射重组腺病毒AdKDR-CDglyTKⅣ组:空白对照,不施加任何处理.重组腺病毒AdKDR-CDglyTK采用瘤体内多点注射,5-FC与GCV给药方法采用腹腔内注射的方法,观察各组小鼠的生存状况及肿瘤体积、瘤重、肿瘤生长抑制率、常规病理等指标;应用透射电镜观察细胞超微结构,用TUNEL法检测细胞凋亡率,比较观察各治疗组的治疗效果;并对各组的肿瘤组织行RTPCR的检测,以了解有无双自杀基因CDglyTK的表达.结果 第Ⅰ组裸鼠移植瘤的生长显著受到抑制,第Ⅱ、Ⅲ、Ⅳ组肿瘤生长情况无明显差别.第Ⅰ组肿瘤细胞凋亡指数为(34.20±4.60)%,较对照组显著增加(P=0.00).结论 AdKDR-CDglyTK联合前药5-FC及GCV对人胰腺癌Capan-2细胞具明显的抑制作用,并且诱导裸鼠体内人胰腺癌Capan-2细胞的凋亡.其可能的机制是通过下调凋亡抑制基因Bcl-2的表达.     

内皮抑素基因对ACHN RCC细胞增殖和凋亡的影响

目的 利用已构建的带有内皮抑素基因真核表达载体质粒导入裸鼠ACHN肾细胞癌(renal cell carcinoma, RCC)细胞中,研究内皮抑素基因对RCC细胞增殖和凋亡的影响.方法 ACHN细胞浓度1×107个/L,经裸鼠右侧背部皮下注射0.2 ml,共注射24只裸鼠.荷瘤裸鼠随机分为3组,每组8只.治疗组:每只裸鼠瘤内3点注射复合物100 μl(内含30 μl梭华-SofastTM和30 μg pSecES质粒);对照组:每只裸鼠瘤内3点注射复合物100 μl(内含30 μl梭华-SofastTM和30 μg pcDNA3.1质粒);空白组:每只裸鼠瘤内3点注射生理盐水100 μl.各组每只裸鼠间隔3 d注射1次,连续注射3次.以增殖细胞核抗原(PCNA)作为细胞增殖状态,按链霉亲和素生物素法(SABC)进行免疫组化染色.细胞凋亡检测用TUNEL法.结果 内皮抑素真核表达质粒能显著抑制裸鼠ACHN RCC肿瘤体积增长,pSecES治疗组平均瘤重明显小于空白组和对照组(P<0.01),与空白组的肿瘤生长抑制率为34.48%,与对照组的肿瘤生长抑制率为40.68%.治疗组肿瘤细胞的凋亡指数(AI)明显高于对照组和空白组(P<0.01).pSecES治疗组肿瘤组织的AI/PI比值明显高于对照组和空白组(F＝189.27,P<0.05).Spearman相关分析表明,肿瘤体积与细胞增殖之间无明显相关性(r =-0.041 2,P>0.05),肿瘤体积与细胞凋亡呈负相关(r =-0.734 6,P<0.01).结论 内皮抑素基因治疗可使裸鼠ACHN RCC肿瘤细胞凋亡增加,肿瘤细胞的数量减少,在总体上表现为肿瘤的生长变慢、体积变小.     

Survivin反义核酸治疗人大肠癌裸鼠皮下种植瘤的实验研究

目的探讨Survivin反义寡核苷酸对裸鼠人大肠癌皮下种植瘤体生长的抑制作用及其机制。方法接种人大肠癌细胞制作裸鼠皮下大肠癌种植瘤模型,分别用Survivin反义寡核苷酸、正义核苷酸和生理盐水对皮下瘤体内直接进行注射治疗,检测肿瘤的生长状况、瘤体体积及瘤重变化,计算抑制率。病理切片免疫组化检测瘤体E-CD表达。结果经Survivin硫代反义寡核苷酸治疗组裸鼠皮下移植瘤生长受到抑制,肿瘤重量明显小于对照组,肿瘤体积明显小于对照组和正义组(P<0.05),裸鼠皮下移植瘤E-CD表达增强。结论Survivin反义核酸可以抑制大肠癌裸鼠移植瘤的生长,Survivin反义核酸抑制大肠癌裸鼠移植瘤生长的机理可能与E-CD基因表达变化有关。     

纳洛酮复合吗啡对裸鼠人胃癌皮下瘤生长的影响

目的观察纳洛酮复合吗啡对裸鼠人胃癌皮下瘤生长的影响。方法建立裸鼠人胃癌MGC-803细胞皮下瘤模型,将50只裸鼠随机分为五组:对照组(C组)、生理盐水组(S组)、20mg/kg吗啡组(M组)、1mg/kg纳洛酮组(N组)、1 mg/kg纳洛酮+20 mg/kg吗啡组(NM组),每组10只。成瘤后,C组不作任何处理;S、M、N组裸鼠每天在右下腹分别腹腔注射生理盐水1.5ml/kg、吗啡20mg/kg或纳洛酮1mg/kg;NM组裸鼠每天在右下腹先腹腔注射纳洛酮1mg/kg,30min后再给予吗啡20mg/kg;连续注射14d。每2天测量1次肿瘤的长径和短径,计算肿瘤相对体积(RTV);用药结束后拉颈处死裸鼠,采用透射电镜观察肿瘤组织的结构变化,免疫组化、半定量逆转录-聚合酶链反应(RT-PCR)和Western blot法检测肿瘤组织中Cyclin D1、血管内皮生长因子(VEGF)、基质金属蛋白酶9(MMP-9)的表达。结果 M组裸鼠皮下瘤RTV为(2.21±0.62)%,明显小于C组的(3.16±0.68)%、S组的(2.98±0.61)%、N组的(3.16±0.35)%和NM组的(2.64±0.37)%(P0.05);NM组裸鼠皮下瘤RTV明显小于C、S和N组(P0.05)。电镜下,C、S、N及NM组皮下瘤组织结构基本正常,M组皮下瘤细胞出现胞浆空泡化、核膜破裂、核染色质边集等。M组裸鼠皮下瘤组织内Cyclin D1、VEGF、MMP-9阳性染色肿瘤细胞、mRNA和蛋白的表达明显低于C组(P0.05);NM组裸鼠皮下瘤组织内Cyclin D1、VEGF、MMP-9阳性染色肿瘤细胞、mRNA和蛋白的表达明显高于M组(P0.05)。结论吗啡可抑制裸鼠人胃癌皮下瘤的生长,纳洛酮可拮抗这一作用,其机制可能与其调节Cyclin D1、VEGF、MMP-9的表达有关。     

白杨素抑制人膀胱癌裸鼠移植瘤生长的初步研究

目的探讨白杨素(Ch R)对膀胱癌T24细胞裸鼠移植瘤生长的影响。方法建立人膀胱癌T24裸鼠皮下异体移植模型(n=40)。接种4周全部成瘤后,将动物随机分为5组:对照组(n=8):腹腔内注射生理盐水,隔日给药1次;丝裂霉素(MMC)组(n=8):腹腔内注射MMC,4 mg/kg,隔日给药1次;低剂量Ch R组(L-Ch R,n=8):腹腔内注射Ch R,20 mg/kg,隔日给药1次;中剂量Ch R组(M-Ch R,n=8):腹腔内注射Ch R,40 mg/kg,隔日给药1次;高剂量Ch R组(H-Ch R,n=8):腹腔内注射Ch R,80 mg/kg,隔日给药1次。连续治疗20 d,裸鼠每周称重2次,测量肿瘤2次,治疗结束处死动物,取出肿瘤称重计算抑瘤率。结果 Ch R(20 mg/kg、40 mg/kg、80 mg/kg)对人膀胱癌T24细胞皮下移植瘤瘤重抑制率分别是40.5%、62.8%和73.4%,与对照组比较,移植瘤重量显著降低(P0.05);不同剂量Ch R组裸鼠的白细胞计数、血清谷丙谷草转氨酶、尿素氮及肌酐与生理盐水模型对照组相比无显著性差异(P0.05)。结论 Ch R能显著抑制人膀胱癌裸鼠移植瘤生长,呈剂量和时间依赖性,是一种毒副作用较小的治疗膀胱癌新候选药物。     

塞来昔布对膀胱癌裸鼠皮下移植瘤及移植瘤细胞凋亡的影响

目的探讨环氧化酶-2(COX-2)抑制剂塞来昔布对膀胱癌裸鼠皮下移植瘤及移植瘤细胞凋亡的影响.方法6周龄BALB/c裸鼠8只,建立膀胱癌裸鼠皮下移植瘤动物模型,分为2组,实验组每kg食物添加1 g塞来昔布,观察塞来昔布对裸鼠健康状况、体重变化及移植瘤变化的影响,并用TUNEL方法检测其对移植瘤细胞凋亡的影响.结果塞来昔布对裸鼠健康状况及体重变化无明显影响(P＞0.05),对移植瘤的生长有抑制作用,肿瘤抑制率为83.7%(P＜0.05),对移植瘤细胞的凋亡有促进作用(P＜0.05).结论塞来昔布可能通过促进肿瘤细胞凋亡等途径对膀胱肿瘤产生抑制作用,可能成为膀胱肿瘤化学预防及治疗的辅助手段.     

靶向β-catenin短发夹RNA抑制人结肠癌裸鼠移植瘤的实验研究

目的探讨靶向β—catenin的短发夹RNA（shRNA）对人结肠癌裸鼠移植瘤的生长抑制作用。方法构建两个靶向β—catenin的短发夹RNA的质粒载体CAT1、CAT2和阴性对照质粒Neg,并将其转入人结肠癌Colo205细胞,分组种植到裸鼠皮下以建立人结肠癌裸鼠移植瘤模型。随后观察监测各组裸鼠的肿瘤生长情况。第8周裸鼠处死并剥离出肿瘤组织,HE染色观察肿瘤细胞的形态,免疫组化方法检测β—catenin蛋白的表达,TUNEL法检测肿瘤细胞的凋亡情况。结果各组裸鼠的内脏未受到明显的毒害和损伤。第8周CAT1、CAT2实验组裸鼠移植瘤的体积和质量与空白对照组相比均有显著性缩小（P〈0．05）,抑制率大约在50％左右。而且与空白对照组相比,CAT1、CAT2组移植瘤的β—catenin表达均有显著性下调,肿瘤细胞凋亡指数均有显著性的升高（P〈0．05）。阴性对照组的上述指标与空白对照组相比差异均无统计学意义。结论所构建的靶向β—catenin的短发夹shRNA能够抑制人结肠癌Colo205细胞裸鼠移植瘤的生长,为结肠癌基因治疗开辟新的思路。     

腺病毒介导反义c-myc基因抑制人肝癌细胞生长的研究

目的观察重组腺病毒介导反义c-myc基因(Ad-ASmyc)对体外培养人肝癌细胞的生长抑制作用和裸鼠体内移植肝肿瘤的治疗效果.方法Ad-ASmyc感染人肝癌细胞系后,观察细胞生长形态变化,通过细胞生长曲线、流式细胞仪分析、逆转录-聚合酶链反应(RT-PCR)、免疫印迹法(Western blot)分析Ad-ASmyc对人肝癌细胞系SMMC-7721和HCC-9204细胞生长、c-myc和bcl-2基因表达的影响;裸鼠皮下移植瘤内注射3种不同剂量Ad-ASmyc(1×109pfu-A组,1×108pfu-B组,1×107pfu-C组)抑制裸鼠肿瘤生长的差异.结果Ad-ASmyc可高效转导人肝癌细胞系SMMC-7721和HCC-9204,抑制细胞生长(抑制率分别为48.72%和56.88%),诱导肝癌细胞G1期阻滞和凋亡,c-myc、bcl-2 RNA及c-myc蛋白水平下降;瘤内注射3种不同剂量Ad-ASmyc均可明显抑制裸鼠皮下移植肿瘤生长,抑制率分别为47.1%、77.3%和82.6%(与对照组比较,P＜0.01).结论重组腺病毒介导的反义c-myc基因能够引起人肝癌细胞c-myc、bcl-2 RNA及c-myc蛋白表达下调和细胞生长抑制,瘤内注射Ad-ASmyc治疗裸鼠皮下移植肝癌有效.     

Synergistic antitumor effect of ionomycin and cisplatin against renal cell carcinoma in vitro and in vivo

Objectives. To characterize the synergistic antitumor effects of the calcium ionophore, ionomycin, and of cisplatin against human renal cell carcinoma cell line, ACHN, both in vitro and in vivo.Methods. The in vitro growth rate of ACHN after exposure to these compounds was measured, using the MTT assay. The apoptotic features in ACHN were evaluated by DNA ladder analysis and flow cytometric analysis. Bcl-2 and Bax expression levels in ACHN after treatment were examined by Western blot. The synergistic antitumor effects of ionomycin and cisplatin against the growth of established ACHN tumors in athymic nude mice were then tested.Results. The in vitro growth rate of ACHN was suppressed more by ionomycin and cisplatin in combination than by either alone. DNA ladder and fragmentation were more obvious when the cells were incubated with ionomycin and cisplatin together than with either reagent alone. Ionomycin treatment increased the expression level of Bax protein, whereas Bcl-2 expression was not influenced. Although an intraperitoneal injection of cisplatin or an intratumoral injection of ionomycin against subcutaneous ACHN tumors somewhat reduced tumorigenicity in nude mice, the effect was significantly enhanced by a combination of these drugs.Conclusions. The synergistic antitumor effects suggest that ionomycin-based therapy could be a novel therapeutic strategy with which to treat advanced renal cell carcinoma.     

Treatment of human renal cell carcinoma by a conditionally replicating herpes vector G207

PURPOSE: Surgical removal remains the only potentially curative therapy for renal cell carcinoma. In this study we evaluated the inhibitory effect of the replication competent engineered herpes simplex virus type 1, G207, for renal cell carcinoma in vitro and in vivo. MATERIALS AND METHODS: The nature of G207 enables it to replicate within cancer cells, thus, causing cytolysis, but replication is restricted within normal cells. The susceptibility of the human renal cancer cell lines ACHN and A498 to G207 at a multiplicity of infection of 0.1 was examined. In addition, the growth characteristics of G207 was assessed. In vivo athymic mice bearing subcutaneous tumors were inoculated with 1 x 10(7) plaque forming units of G207 intra-neoplastically. For pathological analysis subcutaneous tumors were stained with X-gal. RESULTS: Two cell lines were efficiently destroyed by G207 within 1 week. The viral yields of G207 increased in a time dependent manner. In vivo the intra-neoplastic inoculation of G207 caused significantly decreased tumor growth in athymic mice harboring subcutaneous human renal cancer cells. On day 14 the mean growth ratio of ACHN and A498 lesions was significantly inhibited in G207 treated compared to control tumors (p <0.005 and <0.0001, respectively). CONCLUSIONS: These results suggest that G207 should be considered another potential therapeutic agent for renal cell carcinoma.     

内皮抑素基因对ACHN RCC中VEGF和MVD表达的影响

目的：利用已构建的带有内皮抑素基因真核表达载体质粒（pSecES）导入裸鼠人肾癌细胞系肾细胞癌（ACHN RCC）中,研究内皮抑素基因对血管内皮生长因子（VEGF）和微血管密度（MVD）表达的影响.方法：将荷瘤裸鼠随机分为3组,每组8只.干预组每只裸鼠瘤内3点注射复合物100μl,内含30μl梭华-Sofasttm和30μg pSecES质粒;对照组每只裸鼠瘤内3点注射复合物100μl,内含30μl梭华-Sofasttm和30μg pcDNA3.1质粒;空白组每只裸鼠瘤内3点注射生理盐水100μl.各组每只裸鼠间隔3天注射1次,连续注射3次.接种后第34天处死裸鼠,取肿瘤组织按SP法进行免疫组织化学染色,检测MVD和VEGF的表达情况.结果：干预组ACHN RCC的生长较对照组和空白组明显受到抑制,干预组CD34标记的MVD的表达和VEGF的表达较对照组和空白组低.结论：内皮抑素基因导入可以抑制荷瘤裸鼠ACHN RCC的生长,而且MVD和VEGF在ACHNRCC的表达减少.     

siRNA沉默肾癌细胞EGFR基因对放疗敏感性影响的研究

目的：探讨siRNA沉默AcHN肾癌细胞的表皮生长因子受体（epidermal growth factor receptor,EGFR）对放疗敏感性的影响。方法：免疫组化及细胞免疫荧光技术证明组织水平及细胞水平EGFR的表达,化学合成针对EGFR的小干扰RNA,通过脂质体转染法转染进ACHN肾癌细胞中,利用Westernblot技术检测细胞中EGFR蛋白的表达,然后分别用0、2、4、6、8Gy剂量的x线对5组肾癌细胞（每组包含空白对照组、非异性RNA干扰组、特异性RNA干扰组）进行照射,光学显微镜下观察细胞凋亡情况,采用台盼蓝据染法检测细胞凋亡率。结果：靶向EGFR序列的特异性干扰RNA可明显抑制EGFR蛋白的表达,光学显微镜下观察到RNAi联合放疗组细胞死亡情况明显,台盼蓝拒染法检测特异性干扰EGFR基因组可显著提高AcHN肾癌细胞对放疗的敏感性（P〈O．05）。结论：体外研究表明,siRNA沉默ACHN肾癌细胞的EGFR可明显提高肾癌细胞对放疗的敏感性,为肾癌放射治疗提供了新思路。     

Application of the Interferon Minipellet to Human Renal Cell Carcinoma in Nude Mice

Background The interferon (IFN) minipellet is a sustained-release formulation of human lymphoblastoid IFN, with atelocollagen used as the carrier material. We evaluated the antitumor effect of the IFN minipellet on an established human renal cell carcinoma cell line (KU-2) transplanted in nude mice.
Methods The treatment was started when tumor nodules had grown to 6 to 8mm in diameter. The IFN minipellet, or an aqueous solution of IFN, was given by subcutaneous injection, or peritumor injection, on days 1 and 10. Antitumor effects were evaluated according to tumor weights calculated as (long diameter) × (short diameter)²/2 in 7 groups consisting of 6 mice each.
Results IFN levels remained detectable in both tumor tissue and serum up to 10 days after peritumor injection of the IFN minipellet. Administered by the peritumor route, the IFN minipellet inhibited growth of the tumor significantly as compared with tumor growth in the untreated mice. The IFN minipellet showed greater inhibition of tumor growth by peritumor injection compared to subcutaneous injection. The aqueous solution of IFN was not effective either by subcutaneous or by peritumoral injection.
Conclusion Results indicate that the IFN minipellet is useful in the treatment of renal cell carcinoma.     

Verotoxin induces rapid elimination of human renal tumor xenografts in SCID mice

PURPOSE: Verotoxins (VTs) are subunit toxins produced by enteropathogenic Escherichia coli. The VT receptor glycolipid Gb3, which mediates the cytotoxicity of VTs, has been reported to be elevated on the surface of several tumor cell lines. In this study the effect of VT1 as an antineoplastic agent was assessed using various human urological cancer cell lines. MATERIALS AND METHODS: The expression of Gb3 on human cancer cell lines originating from renal cell carcinoma (ACHN, A-704, CAKI-1 and CAKI- 2), prostate cancer (LNCaP and PC3) and testicular tumor (2102Ep) were examined by FACScan (Becton Dickinson, Sunnyvale, California). These cell lines were cultured with various concentrations of VT1 and subjected to microculture tetrazolium dye assay for determination of cell viability. Furthermore, ACHN cells were inoculated into the backs of SCID mice and intratumor injection of VT1 was performed. Pathological samples were examined by hematoxylin and eosin staining as well as by TUNEL assay. RESULTS: The growth of ACHN, CAKI-1, A-704, 2102Ep and LNCaP but not CAKI-2 and PC3 was significantly inhibited by co-incubation with VT1, as determined by microculture tetrazolium dye assays, consistent with FACScan results for Gb3 expression. When mice bearing ACHN tumors were injected with VT1, rapid reduction in the size of subcutaneous tumors was observed with complete regression within 5 to 7 days. Pathological examination by the TUNEL method indicated that the cytotoxicity of VT1 was mediated by apoptosis. CONCLUSIONS: These results suggest that VTs could be candidates for antineoplastic agents against Gb3 expressing tumors for clinical use.     

Studies on anti-tumor activity of tumor necrosis factor alpha against human renal cell carcinoma cells heterotransplanted into nude mice]

The anti-tumor activity of recombinant tumor necrosis factor alpha (rTNF alpha) against the renal cell carcinoma cell line KU-2 was studied in vivo, employing athymic nude mice. The nude mice were divided into six groups and each group was composed of six mice. Group I underwent no treatment, Groups II and III were injected with 5 and 10 micrograms of rTNF alpha intraperitoneally, respectively. Group IV received 5 micrograms of rTNF alpha intravenously and Groups V and VI were administered 2.5 and 5 micrograms of rTNF alpha six times, given intravenously every other day, respectively. Evaluation of the study was performed according to Battelle Colombus Laboratories Protocol. Tumor regression was defined as RW less than 1; inhibition of tumor proliferation was defined as TRW/CRW less than or equal to 42%. Other results were defined as no effect. No obvious anti-tumor activity was observed in group II and III. Though inhibition of tumor proliferation was noted in Group IV, death of two nude mice in this group was noted. When rTNF alpha was administered to the mice in Group V, complete disappearance of the heterotransplanted tumor in two nude mice and tumor regression in four were observed. No death of mice in this group occurred. When the dose of rTNF alpha was raised to 5 micrograms (Group VI), however, five mice died. The histopathological study revealed remarkable necrosis in the tumor tissue and congestion around the white pulps of the spleen 24 hours after intravenous administration of 5 micrograms of rTNF alpha, although no obvious changes were noted in the liver, kidney and digestive organs.(ABSTRACT TRUNCATED AT 250 WORDS)     

Introducing the clusterin gene into human renal cell carcinoma cells enhances their metastatic potential

PURPOSE: We recently reported a protective role of clusterin expression against apoptosis induced by a wide variety of stimuli in several human cancer models. In the current study we tested the hypothesis that clusterin over expression confers a benefit for the metastasis of renal cell carcinoma through the inhibition of apoptosis induced by the various obstacles the cancer cells may confront after detachment from their primary origin. MATERIALS AND METHODS: We introduced clusterin complementary DNA into human renal cell carcinoma ACHN cells, which do not express detectable level of clusterin expression, and generated the clusterin over expressing cell line ACHN/CL and the control vector only transfected cell line ACHN/C. In vitro anti-cell death activity under anchorage independent conditions among ACHN sublines was examined by limiting dilution assay and cell survival assay in suspension. To investigate the in vivo effects of clusterin over expression on metastatic potentials each cell line was injected into the tail vein or renal subcapsule of nonobese diabetic, severe combined immunodeficient mice and the metastatic features in all abdominal and thoracic organs were evaluated. RESULTS: ACHN/CL showed significantly enhanced growth in limiting dilution cultures compared with ACHN/C. The analysis of cell survival in the floating assay also revealed that ACHN/CL had a powerful survival advantage in suspension compared with ACHN/C. Furthermore, ACHN/CL formed more than 5-fold as many metastatic nodules in the lung after intravenous injection than ACHN/C. Similarly more marked lung metastasis was observed after implanting ACHN/CL cells into the renal subcapsule than after implanting ACHN/C cells. In contrast, there were no significant differences among ACHN sublines in the growth rates in vitro and in vivo, cell motility or invasive ability. CONCLUSIONS: These findings suggest that, if clusterin is over expressed, it prolongs cell survival under unfavorable conditions in the metastatic process, resulting in the enhanced metastatic potential of renal cell carcinoma.     

血管生长抑素基因抑制胰腺癌裸鼠移植瘤血管生成的实验研究

目的:探讨人血管生长抑素基因对胰腺癌裸鼠移植瘤生长及血管生成的影响。方法:建立人胰腺癌细胞株BXPC-3裸鼠移植瘤模型,应用人血管生长抑素基因质粒转染胰腺癌裸鼠移植瘤,观察移植瘤生长情况。采用免疫组织化学技术检测肿瘤血管内皮生长因子(VEGF)表达情况和微血管密度(MVD)差异,透射电子显微镜观察肿瘤细胞情况。结果:治疗组肿瘤体积明显小于空白对照组和空质粒组(P<0.01),VEGF主要表达在肿瘤细胞的胞质内,治疗组、空白对照组和空质粒组平均灰度分别为179.57±5.22、150.87±3.44和163.40±3.54;阳性单位分别为14.94±2.26、31.26±2.72和29.21±2.95;MVD分别为10.60±74.56、19.33±2.52和18.67±5.29,治疗组与空白对照组和空质粒组比较,差异有统计学意义(P均<0.05)。电子显微镜下治疗组可见大量肿瘤细胞坏死。结论:人血管生长抑素基因能明显抑制胰腺癌裸鼠移植瘤血管生成,促进肿瘤细胞坏死,进而抑制肿瘤生长。