荷瘤裸鼠放射自显影受体辨别的实验研究

背量：应用放射性核素标记小分子肽类配体进行肿瘤受体显像。针对肿瘤组织所表达的高密度αvβ3受体，发展放射性标记的含RGD序列的高选择性αvβ3受体拮抗剂，是目前肿瘤受体显像研究的热点。目的：以实验动物为基础，探讨放射性核素标记小分子环形多肽RGD-4 CY实现肿瘤αvβ3受体显像的可行性。设计：完全随机的实验对照。地点和对象：实验在解放军第三军医大学西南医院核医学中医学中心完成研究对象为25只正常小鼠和15只荷人QBC939胆管癌裸鼠，由解放军第三军医大学实验动物中心提供，4—6周龄，体质量15—20g。干预：采用Iodogen法标记、SEP-PAK C18柱分离纯化制备^125I-RGD-4CY。取25只正常小鼠与15只荷人QBC939胆管癌裸鼠。经尾静脉注射^125I-RGD-4CY 0．1mL(370kBq)，分别于注射后10，30，60，120和240min各取5只与3只处死，测定体内放射性的生物分布。取3只荷瘤裸鼠各注射0．1mL(3．7MBq)^125I-RGD-4CY，1h后处死并行全身放射自显影。主要观察指标：^125I-RGD-4CY的放射化学纯度；^125I-RGD-4CY的体内分布及动力学特点，肿瘤(T)与非肿瘤组织(NT)放射性比值；自显影图像中瘤体及正常组织的放射性分布。结果：^125I-RGD-4 CY的放射化学纯度为99％。正常小鼠血液放射性清除和肝脏放射性下降迅速，肠道无明显增加，主要通过肾脏排泄。肌肉和肺的放射性120min时分别仅为肝脏的32％与44％(t值为3．33与3．64，P&;lt;0．05)。荷瘤裸鼠各时相肿瘤的放射性均高于肌肉、肠道与肺(t值为3．18～13．24，P&;lt;0．05～0．01)，240min时T／NT值分别为26，8．7与26。放射自显影示肿瘤放射性浓聚影最强，肺、颈部及其他软组织呈低水平分布。结论：放射性核素标记RGD-4CY有望成为一有效的肿瘤αvβ3受体显像剂。     

超声治疗裸鼠移植癌的实验研究

目的观察高强度聚焦超声（ＨＩＦＵ）治疗裸鼠移植癌的疗效，探讨局部肿瘤非手术“切除”的可能性。方法将ＢＡＬＢ／Ｃ裸鼠背部接种Ｈ２２肿瘤细胞造模后，分为ＨＩＦＵ组２０只，对照组１０只。ＨＩＦＵ组采用频率为３．５ＭＨｚ超声，声头直径４ｃｍ，聚焦深度３．１ｃｍ，声强３００Ｗ／ｃｍ２，聚焦直径０．３５ｃｍ，纵深度０．５ｃｍ，连续波每次作用于病变局部３０秒，热电偶电极测得靶区温度为８５℃，每周５次，共４周累计１０分钟。检测作用前后肿瘤直径，观察肿瘤抑制率及病理组织变化。结果ＨＩＦＵ作用４周后，ＨＩＦＵ组与对照组肿瘤直径分别为（１．１０±０．４８）ｃｍ和（２．４５±０．８７）ｃｍ，Ｐ＜０．０５，肿瘤抑制率为９５％。其中５只裸鼠肿瘤完全脱落，而周围正常组织完好，未发现转移病灶。病理切片可见癌组织大片坏死，及癌巢间大片空泡变性；对照组裸鼠全部死亡。结论ＨＩＦＵ疗法是一种治疗局部肿瘤无创性的有效治疗方法。     

气味沙雷氏菌P16组分对荷瘤裸鼠的保护作用

背景气味沙雷氏菌苗可抑制肿瘤的生长和体外肿瘤细胞的增殖,其P16组分亦可体外抑制肿瘤细胞的增殖.目的检测气味沙雷氏菌P16组分对荷QGY肿瘤裸鼠的保护作用.设计随机对照、重复测量设计.地点和对象在海军医学研究所防护医学研究室完成.雄性BALB/c裸鼠,6周龄,SPF级,购自上海市肿瘤研究所实验动物研究室.干预将BALB/c裸鼠接种QGY肿瘤细胞.按随机数字表法分为P16组和对照组各6只,3 d后P16组瘤内注射100μgP16,对照组瘤内注射同体积的生理盐水,分8个时间点测量肿瘤体积变化以及瘤块的质量.主要观察指标①各时间点肿瘤体积的变化.②26 d剥离瘤块的质量.③两组裸鼠生存时间.结果对照组裸鼠接种肿瘤细胞26 d开始死亡,至44d时全部死亡.与对照组相比P16组的平均生存时间显著延长达到30%.自第8天开始P16组与对照组瘤体积差异有显著性意义(P＜0.01),第26天分别为(2.50±0.15),(7.16±0.42)cm3,P16组的瘤重与对照组相比差异有显著性意义.结论P16可直接抑制QGY肿瘤的生长,对荷瘤裸鼠有显著地保护作用.     

抑制Smac基因表达对胰腺癌裸鼠移植瘤生长影响的研究

[目的]探讨Smac基因对人胰腺癌裸鼠移植瘤生长的抑制作用.[方法]于裸鼠腋下接种200 μL 107/mL的PANC-1细胞悬液,建立人胰腺癌裸鼠移植瘤模型,将其分为三组：注射PBS液（A组）、转染空载体（B组）、转染Smac基因（C组）,比较三组移植瘤的大小、移植瘤细胞的凋亡率,移植瘤中Smac蛋白表达和微血管密度（MVD）.[结果]与A、B组比较,C组裸鼠移植瘤体积、质量和MVD显著减小;移植瘤细胞的凋亡指数和Smac蛋白的表达率均明显增高,其差异均有统计学意义（P〈0.05）.[结论]脂质体转染Smac基因能抑制人胰腺癌裸鼠移植瘤的生长,可能与该基因诱导胰腺癌细胞凋亡和抑制肿瘤血管形成有关.     

体外冲击波对骨膜组织影响的放射性自显影研究

目的了解高能冲击波治疗骨折延迟愈合、骨折不连接的作用机理.方法采用体外高能冲击波作用于骨组织,通过动物实验,骨膜组织体外培养H3-TdBR掺入放射性自显影研究.结果证实冲击后1、2、4周,实验侧骨膜组织H3-TdR标记率明显高于对照侧(P＜0.05),表明实验侧骨膜成骨细胞有丝分裂明显加强,骨膜成骨作用增强.结论高能冲击波可使骨膜组织成骨作用加强.     

替勃龙对去势裸鼠子宫内膜癌移植瘤的影响

目的 通过裸鼠子宫内膜癌移植瘤模型的体内实验,探讨替勃龙应用于子宫内膜癌患者的安全性.方法 (1)体外培养人子宫内膜癌Ishikawa细胞株;建立去势裸鼠子官内膜癌Ishikawa细胞株皮下移植瘸动物实验模型;(2)将成瘤裸鼠随机分为替勃龙组(15只)和对照组(15只),分别予以替勃龙0.375mg·kg-1·d-1和对照治疗35 d;(3)比较给药前后两组肿瘤体积变化、肿瘤重量和肿瘤转移状况(体表、盆腹腔淋巴结、腹水);应用免疫组化SP法测定两组实验动物皮下移植瘤Ki67、P53、P27、bcl-2蛋白表达情况,判断替勃龙对移植瘤的影响和对内膜癌细胞增殖及凋亡的影响.结果 (1)替勃龙组和对照组裸鼠两组子宫内膜癌皮下移植瘤体积变化无统计学差异[ (2.063±1.038) cm3饥 vs.(2.170±0.822) cm3,P=0.791];肿瘤重量无统计学差异[(0.699±2.02)gvs.(0.807±2.83)g,P =0.314];替勃龙治疗35 d后,没有引起子宫内膜癌肿瘤体表、盆腹腔转移和腹水发生;(2)替勃龙组和对照组两组裸鼠人子宫内膜癌Ishikawa细胞株皮下移植瘤Ki67增殖指数、P53、P27、bcl-2蛋白表达情况均无统计学差异.结论 替勃龙不刺激裸鼠子宫内膜癌Ishikawa细胞株皮下移植瘤生长、转移和细胞增殖、凋亡.替勃龙应用于子宫内膜癌患者的术后激素补充治疗可具有一定的安全性.     

水苏碱对胃癌移植瘤小鼠肿瘤生长及基因表达的影响

【目的】探讨水苏碱对胃癌移植瘤裸鼠肿瘤生长及CyclinD1、c-myc、Bcl-2、c-Met、p53、p16、Bax、Caspase-3表达的影响。【方法】培养人胃癌SGC-7901细胞株后制备细胞悬液,将细胞悬液接种至BALB/c裸鼠皮下得到胃癌移植瘤小鼠模型,随机分为用生理盐水灌胃的对照组、用水苏碱(stachydrine,STA)灌胃的STA组。干预后21d,测定移植瘤体积、重量及移植瘤中上述癌基因的表达。【结果】STA组的移植瘤体积、重量均明显低于对照组;移植瘤中cyclinDl、c-myc、Bcl-2、c-Met的蛋白表达量均明显低于对照组,而p53、p16、Bax、Caspase-3的蛋白表达量均明显高于对照组。【结论】水苏碱能够抑制胃癌移植瘤小鼠的肿瘤生长并使移植瘤中的原癌基因表达下调、抑癌基因表达上调。     

医用胶粘贴法建立人胃癌裸鼠原位移植模型

目的：建立人胃癌裸鼠原位移植高转移模型。方法：用医用胶将裸鼠皮下实体瘤块粘贴在裸鼠胃壁,定时观察裸鼠全身情况,分不同时期处死,观察其生长及转移特性。结果：裸鼠原位成瘤率100%,术后5-6周原位肿瘤逐渐增大,8-10周局部包块透壁可见,有肝肺等脏器转移。10-12周动物极度消瘦,部分动物腹水形成,逐渐衰竭,濒临死亡。结论：通过胶粘贴法构建人胃癌原位移植转移模型,成功率高,能较好地重现胃癌的临床生长过程,为人类研究胃癌提供了一种较理想的动物模型。     

重组人生长激素对人结肠癌裸鼠原位移植瘤生长的影响

目的通过建立人结肠癌细胞株COLO-320裸鼠原位移植瘤模型,探讨重组人生长激素(rhGH)对移植瘤生长的影响,从而为临床能否应用rhGH提供实验依据。方法经4次传代,将生长稳定的20只荷瘤裸鼠随机分为4组:(1)对照组;(2)rhGH组;(3)羟基喜树碱(HCPT)组;(4)rhGH加HCPT组。接种次日开始给药,连续用药35d后,处死裸鼠,留取移植瘤标本,测定移植瘤体积、重量、凋亡率、细胞周期及增殖指数(PI),常规HE染色,光镜下观察。结果与对照组比较,rh-GH组差异无统计学意义(P>0.05),而HCPT组差异有统计学意义(P<0.001);对照组移植瘤体积、重量、凋亡率及增殖指数分别为(2764.80±120.51)cm3、(2.52±0.10)g、(13.24±0.76)%、(30.14±0.71)%,而HCPT组则分别为(946.6±48.33)cm3、(0.89±0.09)g、(37.13±0.72)%、(15.50±0.74)%;rhGH不影响HCPT的作用(P>0.05)。结论rhGH对人结肠癌细胞株COLO-320移植瘤的生长既无促进作用,亦无抑制作用。     

Tumor localization and biodistribution with radiolabeled monoclonal antibody against pancreatic cancer in tumor-bearing nude mice.

Nd2 is a murine monoclonal antibody produced against a mucin fraction purified from xenografts of a human pancreatic cancer cell line SW1990. Immunoperoxidase staining showed that the antigen recognized by Nd2 was present in 82.9% of pancreatic cancer tissues but not in tissues of normal pancreas and chronic pancreatitis. However Nd2 antigen was found not to be elevated in the sera of patients with pancreatic cancer. Four days after injection of 111In-Nd2 into athymic nude mice bearing SW1990 xenograft there was a higher accumulation in the tumor compared to 111In-normal mouse IgG1. When these mice were scanned with a gamma camera, labeled Nd2 was shown to accumulate in the tumor rapidly on the 1st day after injection and by the 4th day tumor accumulation was more distinctly visualized than non-specific accumulation in liver. These results indicate that Nd2 has high specificity and reactivity for pancreatic cancer and may have possible applicants in radioimmunodetection or targeting of therapeutic drugs in pancreatic cancer.     

神经母细胞瘤原位荷瘤与转移瘤裸鼠模型建立的实验研究

目的用自建的细胞系QDDQ建立起原位荷瘤与转移瘤裸鼠模型,探讨神经母细胞瘤(Neuroblastoma,NB)的转移特性。方法取NB新鲜瘤组织,利用酶消化法,建立起体外细胞系,以(3～7)×107/ml浓度的单细胞悬液0.5 ml接种于裸鼠,建立荷瘤鼠模型。结果 NB原位荷瘤与转移瘤裸鼠模型成功建立,实验鼠共30只,致瘤25只,致瘤率为83.3%。10只原位荷瘤,15只转移荷瘤。结论建立NB细胞动物模型,对于进一步研究其转移特性、分子生物学特征,提供了良好的平台。     

Antitumor activity of lipopolysaccharide in tumor-bearing mice pretreated with BCG

The antitumor activity of lipopolysaccharide (LPS) was investigated in BCG-treated mice. C3H/He mice and CDF1 mice were injected with BCG and then were inoculated with syngeneic mouse hepatoma MH134 and mastocytoma P815 respectively. Hemorrhagic necrosis and retarded growth of tumor were observed after an intravenous (i.v.) injection of LPS, when tumor cells had been inoculated subcutaneously (s.c.). However an intraperitoneal (i.p.) injection of BCG plus LPS did not increase the mean survival time of mice that had been inoculated with tumor cells i.p. Sera from mice that had been treated with BCG plus LPS i.v. were cytotoxic for cultured tumor cells. These results seemed to indicate that growth-inhibitory effects of LPS on tumors inoculated s.c. were mediated by a humoral factor.     

Adoptive immunotherapy in tumor-bearing mice with OK-432-induced killer cells

Murine spleen cells cultured for 3 or more days in medium with streptococcal preparation OK-432 became cytotoxic in vitro against several allogeneic and syngeneic tumor cells. These cytotoxic cells were designated OK-432-induced killer (OIK) cells. This study examined the in vivo antitumor efficacy of OIK cells in adoptive immuno- and immunochemo-therapy in mice bearing syngeneic tumors, such as EL-4 lymphoma, Meth-A fibrosarcoma, and MOPC-31C plasmacytoma. OIK cells neutralized these tumor cells, as shown by Winn-type tests, and the cell transfer prolonged the survival of mice inoculated intraperitoneally (ip) with EL-4 or Meth-A cells. Concomitant administration of OK-432 plus recombinant interleukin 2 (rIL-2) significantly improved the therapeutic efficacy of the transferred OIK cells. In mice inoculated with 1 x 10(4) EL-4 cells, chemoimmunotherapy consisting of ip administration of 200 mg/kg cyclophosphamide on day 3 followed by treatment with OIK cell (1 x 10(7)) transfer and with OK-432 (50 KE/kg) plus rIL-2 (50 units/mouse) 6 hr later and on day 6, prolonged the survival. Therefore, the immunotherapy with OIK-cell transfer followed by administration of OK-432 and rIL-2 may be clinically useful as an adjunct of cytoreductive chemotherapy for cancer.     

Tissue distribution and metabolism of the tyrosine kinase inhibitor ZD6474 (Zactima) in tumor-bearing nude mice following oral dosing

ZD6474 [N-(4-bromo-2-fluorophenyl)-6-methoxy-7-[(1-methylpiperidin-4-yl)methoxy]-quinazolin-4-amine; Zactima] is a tyrosine kinase inhibitor with antiangiogenic and antitumor activity currently undergoing human trials for cancer treatment. Pharmacokinetic studies in animal models are an important component in the clinical development of this agent to relate preclinical studies to patient treatment. In the studies presented here, the pharmacokinetics of ZD6474 was determined in plasma and tissues of MCF-7 tumor-bearing nude mice following single p.o. doses at 10, 25, and 50 mg/kg. Plasma area under the curve and Cmax were linear, increasing proportionally with dose. Tissue analysis showed that ZD6474 is extensively distributed to tissues, with liver and lung accumulating concentrations of 212 microg/g (approximately 450 microM) and 161 microg/g (approximately 340 microM), respectively. Tumor levels ranged from 27 to 71 microg/g at Cmax levels across the three dose ranges, and ZD6474 was distributed to all of the tissues in a dose-dependent manner. Analysis of putative ZD6474 metabolites in feces found four, with the N-demethyl-piperidinyl-ZD6474 metabolite being the most prominent but still accounting for less than 2% of the total amount of ZD6474 present. The lack of significant metabolism of ZD6474 is consistent with the relatively long half-life in mice (approximately 30 h), as well as that seen in humans (approximately 120 h), and the primary method of drug elimination appears to be unchanged in the feces (approximately 25%). The incorporation of an empirical approach to dosing in mouse models of cancer in preclinical studies may allow for better prediction of clinical efficacy for ZD6474 alone and in combination with other therapeutic modalities based on equivalent drug exposure.     

Regressor serum factor-dependent nonspecific killers in tumor-bearing mice

Spleen cells obtained from C3H/He or C57BL/6 mice bearing syngeneic ascitic tumor cells in the early stage of tumor progression had activity to lyse various tumor cells in vitro when serum from MM2-regressor C3H/He was added to the reaction mixture. The serum component responsible for the reaction was of non-immunoglobulin nature. The serum factor-dependent cytotoxic cells were Thy-1-positive cells which were not adherent to nylon wool or Sephadex G-10 and were not natural killer cells. Allogeneic tumor cells and syngeneic tumor cells of near-tetraploid chromosomes were susceptible to such lysis whereas syngeneic near-diploid cells were resistant. The serum factor was absorbed by susceptible cells and not by resistant cells.     

Antitumor activity of cyclophosphamide and lipopolysaccharide in tumor-bearing mice pretreated with BCG

Antitumor effects of cyclophosphamide (CY) and lipopolysaccharide (LPS) were investigated in BCG-treated mice. C3H/He mice and CDF1 mice were injected with BCG and were inoculated subcutaneously with syngeneic mouse hepatoma and mastocytoma P815 respectively. A subsequent injection of LPS caused hemorrhagic necrosis and retarded growth of tumor. When mice were treated with LPS plus suboptimal dose of CY, tumor growth was retarded and survival time was prolonged. The antitumor effects were more remarkable when mice were treated with CY prior to the injection of LPS. Without BCG pretreatment, LPS showed no antitumor activity in mice. Sera from mice treated with BCG plus LPS was cytotoxic for cultured tumor cells. However treatment of mice with CY did not increase the in vitro cytotoxicity. In this experimental condition, CY had no effect on delayed type hypersensitivity when evaluated by the footpad reaction to purified protein derivative (PPD). These results seem to indicate that the antitumor effects of the treatment with CY and LPS in BCG-treated mice are mediated by the reduction of tumor burden by CY and a serum factor induced by LPS.