肝癌细胞不同制悬方法建立裸鼠移植瘤模型的比较

目的比较肝癌细胞不同制悬方法建立裸鼠皮下瘤及原位瘤模型,优选建模方法。方法将肝癌细胞分别采用PBS缓冲液(PBS组)、无血清DMEM溶液(DMEM组)和含10%血清的DMEM溶液(血清DMEM组)3种液体制悬后注入裸鼠皮下建立肝癌裸鼠皮下瘤模型,比较皮下瘤的体积、瘤重及成瘤率;将肝癌细胞分别采用PBS缓冲液(PBS组)、无血清DMEM溶液(DMEM组)和含10%血清的DMEM溶液(血清DMEM组)3种液体制悬后注入裸鼠肝脏建立肝癌裸鼠原位瘤模型,比较原位瘤的成瘤率。结果3组裸鼠皮下瘤模型的皮下瘤体积及瘤重相比,差异无统计学意义(P0.05),但是PBS组及DMEM组的成瘤率(90%和100%)明显高于血清DMEM组(40%),差异有统计学意义(P0.05);裸鼠原位瘤模型中PBS组的成瘤率(90%)明显高于DMEM组(40%)及血清DMEM组(20%),差异有统计学意义(P0.05)。结论采用PBS缓冲液或无血清DMEM溶液对肝癌细胞稀释制悬可以有效建立裸鼠皮下瘤模型,采用PBS缓冲液对肝癌细胞稀释制悬可以有效建立裸鼠原位瘤模型。     

Metastatic models of human liver cancer in nude mice orthotopically constructed by using histologically intact patient specimens

In this study of orthotopic implantation of histologically intact surgical specimens, the authors constructed metastatic models of human hepatocellular carcinoma (HCC) in nude mice. Histologically intact human liver cancer specimens, derived from patients, were implanted directly into the liver of nude mice, and their orthotopic growth and metastases were observed. The transplantability and metastatic rate of two specimen groups (primary and metastatic lesions) were analysed. -Fetoprotein (AFP) was also determined in transplanted tumours by an immunohistochemical method. Orthotopic growth was observed in 14 of 30 transplanted specimens and formation of metastases in 7 cases, which exhibited the variety of clinical behaviours seen in patients with HCC. These behaviours included local growth, regional invasion, spontaneous intrahepatic, lymph node and lung metastasis and peritoneal seeding. In two groups the growth rate of metastatic lesions following implantation was clearly higher than that of primary tumours. Chromosome analysis from locally growing tumours confirmed their morphologically human origin. An immunohistochemical study showed that implanted tumours originating from AFP-positive specimens maintained AFP expression. These results indicated that the animal models should prove valuable for developing new treatment modalities and studying the mechanism of metastasis of human HCC.Abbreviation HCC hepatocellular carcinoma - AFP -fetoprotein     

An orthotopic nude mouse model for preclinical research of gastric cardia cancer

PURPOSE: A clinically relevant animal model for cancer of the esophagogastric junction does not exist. This study aimed to establish an orthotopic mouse model for human gastric cancer of the distal stomach and the gastric cardia. MATERIALS AND METHODS: Human gastric cancer cell lines AGS, MKN-45, and NCI-N87 were injected subcutaneously into nude mice. These donor tumors were harvested after 4 weeks and minced into small tumor fragments. One donor tumor fragment was orthotopically implanted into the submucosa of either gastric cardia or distal stomach in other mice. The animals were killed 4, 8, and 12 weeks after tumor implantation. Volume of the primary tumor and local and systemic tumor spread were determined. RESULTS: The implantation technique resulted in a tumor take rate of 100%. An artificial dissemination of tumor cells into the abdominal cavity due to the procedure was not observed. CONCLUSIONS: We report for the first time the development of a clinically relevant mouse model for human gastric cancer of the gastric cardia and the distal stomach. Primary tumor growth and local and systemic spread progressed continuously during the observation period and mimic the human situation of this disease. This model may be suitable to evaluate novel treatment strategies for this malignancy.     

Anti-tumor activities and apoptosis-regulated mechanisms of bufalin on the orthotopic transplantation tumor model of human hepatocellular carcinoma in nude mice

AIM： To investigate anti-tumor activities and apoptosisregulated mechanisms of bufalin in the orthotopic transplantation tumor model of human hepatocellular carcinoma in nude mice.
METHODS： BEL-7402 cells of human hepatocellular carcinoma were inoculated to form subcutaneous tumors, and were implanted into the liver to establish orthotopic transplantation tumor models of human hepatocellular carcinoma in nude mice. Seventy-five animals were randomized divided into five groups （n = 15）. Bufalin was injected intraperitoneally into three groups at doses of 1.5 mg/kg （BF1）, 1 mg/kg （BF2） and 0.5 mg/kg （BF3） for d 15-24, respectively. The NS group was injected an equal volume of saline as above and adriamycin was injected intraperitoneally into the ADM group at a dose of 8.0 mg/kg for d 15. Ten mice in each group were killed at d 25 and the survival time in each group was calculated. We also observed the morphologic alterations in the myocardium, brain, liver, kidney and tumor tissues by pathology and electron microscopy, measured the apoptotic rate by TUNEL staining method, and detected the expression of apoptosis-regulated genes bcl-2 and bax by immunohistochemical staining and RT-PCR in tumor tissues.
RESULTS： The tumor volumes in each group of bufalin were reduced significantly （35.21±12.51 vs 170.39 ± 25.29; 49.83 ± 11.46 vs 170.39 ± 25.29; 83.99 ± 24.63 vs 170.39 ± 25.29, P 〈 0.01, respectively）, and the survival times were prolonged in group BF1-2 （31.8 ± 4.2 vs 23.4 ± 2.1 and 29.4 ± 3.4 vs 23.4 ± 2.1, P 〈 0.05, respectively）, and necrosis was mainly in severe or moderate degree in group BF1-2. No morphological changes were detected in the myocardium, brain, liver and kidney tissues. Apoptotic characteristics could be seen in group BF1-2. The positive rates of bcl-2 and bax protein expression of each group by immunohistochemical staining were 10.0%, 10.0%, 20.0%, 10.0% and 20.0%; 90.0%, 80.0%, 80.0%, 40.0% and 30.0%, respectively. Loss of expression of bcl-2 mRNA     

胃癌实验模型建立的研究现况

胃癌死亡率居全球恶性肿瘤第二位,占癌症总死亡率的9.7%.胃癌的发生是多步骤、多因素的,诸如致病细菌、宿主遗传因素和免疫应答等.动物模型在研究胃癌生物学行为和临床诊治过程中占有重要地位.本文将分别从微生物原位诱发、化学致癌剂原位诱发、癌细胞定植、转基因模型和计算机模拟五方面重点阐述胃腺癌模型建立的现况.     

Details determining the success in establishing a mouse orthotopic liver transplantation model

Liver transplantation(LT) is currently the only effective treatment option for endstage liver disease. The importance of animal models in transplantation is widely recognized among researchers. Because of the well-characterized mouse genome and the greater diversity and availability of both genetically modified animals and research reagents, mouse orthotopic LT(MOLT) has become an ideal model for the investigation of liver biology, tissue injury, regulation of alloimmunity and tolerance induction, and the pathogenesis of specific liver diseases. However, due to its complicated and technically demanding procedure, the model has merely been used by only a few research groups in the world for years. For a new learner, training lasting at least a couple of months or even years is required. Most of the investigators have emphasized the importance of elaborate techniques and dedicated instruments in establishing a MOLT model, but some details are often neglected. The nontechnical details are also significant, especially for researchers who have little experience in mouse microsurgery. Here, we review and summarize the crucial technical and nontechnical details in establishing the model of MOLT based on scientific articles and our experience in six aspects: animal selection, anesthesia, perioperative management, organ procurement, back-table preparation, and implantation surgery. We aim to enable research groups to shorten the learning curve and implement the mouse LT procedure with high technical success.     

Tumorigenicity,invasion, and metastasis of human gastric cancer in nude mice

Summary Tumors derived from 105 patients with gastric cancer were subcutaneously heterotransplanted into nude mice in order to study their tumorigenicity and malignant behavior. Of the 105 gastric cancers, 45 were successfully transplanted (a 42.9% tumorigenesis rate). The tumorigenesis rate of Borrmann type 1 and 2 cancers (77.8%) was significantly higher than that of type 3 and 4 cancers (34.6%). Also, the tumorigenesis rate of differentiated carcinoma (57.1 %) was significantly higher than that of undifferentiated carcinoma (30.9%). Spontaneous metastases from the subcutaneous tumors were observed in 5 of the 37 established tumor lines (13.5%), and macroscopic pulmonary metastases were common with one tumor line (SCK-29). Although most of the subcutaneous gastric cancers showed local expansion without distant metastasis, the same tumor cells implanted into the peritoneal cavity exhibited invasive growth and/or metastasis. Thus, the expression of a metastatic pheno-type by human gastric cancer was influenced by the host microenvironment. The SCK-29 tumor line with its high metastatic potential may be useful for studies on the mechanism of blood-borne metastasis.Abbreviations pap papillary adenocarcinoma - tub₁ well-differentiated adenocarcinoma - tub₂ moderately differentiated adenocarcinoma - por poorly differentiated adenocarcinoma - sig signet-ring cell adenocarcinoma - muc mucinus adenocarcinoma - giant giant cell adenocarcinoma - ud undifferentiated adenocarcinoma - ade ascitic adenocarcinoma This study was supported in part by a grant-in aid for cancer research (B.no. 63480309) from the Ministry of Education, Science and Culture, Japan     

下调CD44基因表达对人胃癌SGC7901细胞裸鼠移植瘤的抑制作用及其机制

目的探讨靶向CD44的短发夹RNA(shRNA)对人胃癌裸鼠移植瘤生长抑制作用及其机制。方法利用CD44 shRNA细胞及对照细胞株建立裸鼠原位移植瘤及皮下种植瘤模型,监测肿瘤生长变化,采用RT-PCR及免疫组织化学方法检测瘤体内CD44表达的变化,并进一步检测上皮-间质转化(EMT)相关因子表达的变化。结果成功构建了CD44 shRNA转染荷瘤皮下及原位裸鼠模型。与对照shRNA组、空白对照组分别比较,CD44 shRNA组荷瘤裸鼠肿瘤生长速度减慢,皮下种植瘤及原位移植瘤质量减轻,差异均有统计学意义(P均0.01)。RT-PCR结果发现,CD44 shRNA组CD44mRNA表达在皮下种植瘤及原位移植瘤均显著下调,差异均有统计学意义(P均0.01)。CD44 shRNA组细胞EMT相关基因E-cadherin表达增加,N-cadherin、Vimentin表达降低。结论 CD44 shRNA可以有效抑制人胃癌SGC7901细胞裸鼠移植瘤生长,并下调CD44的表达水平,这可能与CD44基因参与EMT相关。     

顺铂结合CIK细胞对裸鼠人胃癌模型体内的抗肿瘤作用

目的:探讨顺铂、CIK细胞以及顺铂联合CIK对裸鼠人胃癌移植瘤生长的抑制作用,为临床上联合应用顺铂和CIK细胞治疗胃癌提供实验依据.方法:应用淋巴细胞分离液分离外周血单个核细胞,给予多种细胞因子(rhIFN-g、CD3mcAb、rh1L-1、rhlL-2),诱导生成CIK细胞;培养人胃癌细胞株SGC-7901,接种至80只裸鼠右腋皮下,10 d后取移植瘤直径基本一致的裸鼠随机分4组:NS对照组、顺铂组、CIK细胞组和顺铂+CIK细胞组,每组16只.连续5 d在接种肿瘤细胞部位处给予相应注射治疗,观察其对胃癌移植瘤模型的抗肿瘤疗效.结果:与NS对照组相比,顺铂组、CIK细胞组、顺铂+CIK细胞组裸鼠人胃癌移植瘤模型治疗后肿块质量均减轻,生存期均明显延长,尤以顺铂+CIK组效果显著(P<0.01).裸鼠体内实验表明,顺铂+CIK细胞联合应用能够显著抑制胃癌细胞的生长,其抑瘤率可达57.8%,明显高于NS对照组(P<0.01).免疫功能检测显示红细胞C3b反应受体明显升高,红细胞免疫复合物受体明显降低(P<0.01).结论:顺铂联合CIK细胞对人胃癌移植瘤生长的抑制作用大于单独应用顺铂或CIK细胞.     

Impact of p27mt gene on transplantation model of human colorectal cancer in nude mice

AIM： To investigate the inhibitory and anti-metastatic effect of mutant p27 gene （p27mt） on the growth of colorectal cancer xenografts in nude mice and its underlying mechanism. METHODS： Inhibitory effect of p27mt gene on the growth of colorectal cancer xenografts was determined by measurement of tumor size before and after direct intra-tumoral injection of Ad-p27mt in a pre-established transplantation model of human colorectal cancer in nude mice. Cell cycle and apoptosis were detected by flow cytometry performed on single-cell suspension from an isolated tumor. Expression of MMP-9 in tumor tissue was detected by immunohistochemistry. RESULTS： The average sizes of transplantation tumors were 1.94 ± 0.67 cm^3, 2.75 ± 0.83 cm^3 and 3.01 ± 0.76 cm^3 in the Ad-p27mt, Ad-LacZ and control groups, respectively （P 〈 0.05）. The average proliferation rates were 37.34% ± 1.45%, 53.16% ± 3.27% and 54.48% ± 2.43%, in the Ad-p27mt, Ad-LacZ and control groups, respectively （P 〈 0.05）. The average apoptosis rates were 19.79% ± 3.32%, 6.38% ± 4.91% and 7.25% ± 5.20% in the Ad-p27mt, Ad-LacZ and control groups, respectively （P 〈 0.01）. The average MMP-9 expression rates were 20%, 75% and 66.7% in the Ad-p27mt, Ad-LacZ and control groups, respectively （P 〈 0.01）. CONCLUSION： p27mt inhibits the growth of transplanted tumor by blocking the proliferation of cancer xenografts and by promoting apoptosis of transplantated tumor cells, as well as decrease transplanted tumor metastasis.     

人胰腺癌细胞株PANC1裸鼠原位模型的建立及磁共振监测

目的 建立一种稳定的人胰腺癌裸小鼠原位移植瘤模型,并探讨无创的磁共振(MRI)对其监测的应用价值.方法 人胰腺癌细胞株PANC1体外常规传代后建立裸鼠皮下种植瘤模型,将皮下种植瘤制成细胞悬液,植入20只BALB/C-nn裸鼠的胰腺包膜下构建人胰腺癌原位移植模型;通过MRI检查监测模型的成瘤率、成瘤时间、肿瘤生长速度、肿瘤形态、信号变化等特征,于第7周末取肿瘤组织行病理学检查.结果 接种后15 d,7只(35%)荷瘤鼠在MRI上显示成瘤,至接种后27 d,成瘤率为100%.肿瘤信号与邻近组织相比,90%(18/20)病灶T1WI呈均匀稍低信号,10%(2/20)呈等信号;75%(15/20)在T2WI呈均匀高信号.移植后2、3、4、5、6、7周经MRI测量的移植瘤体积分别为(12.6±2.4)mm3、(94.3±11.2)mm3、(175.9±82.5)mm3、(395.8±126.6)mm3、(1290.2±167.2)mm3、(1583.4±87.4)mm3.病理学检查确诊为胰腺低分化腺癌,并保持原发瘤的生物学特征.结论 人胰腺癌细胞株PANC1移植瘤制成的细胞悬液种植裸小鼠胰腺包膜下制备胰腺癌模型符合人胰腺癌的特征,且易于无创监测,为临床研究提供了一个有效、稳定的体内实验体系.     

In vivo induction of neoplastic growth in nude mouse connective tissue adjacent to xenografted human tumors

Summary Induction of neoplastic growth of murine stroma cells within the human tumor xenograft was observed after serial passage of CEA and 2-microglobulin producing human colonic SLu tumor xenografts in nu/nu BALB/c mice. Mouse tumors within the human tumor xenografts wre identified using specific immunohistologic staining techniques for mouse histocompatibility marker or human CEA. These mixed tumors could be distinguished from normal human tumor xenografts by a different relationship between development of the tumor marker in the serum and tumor size. We were able to establish transformed murine cells from human xenografts, either induced by SC injection of 1×10⁶ tumor cells of the SLu cell line or by human SLu or mammary carcinoma tissue serially passaged in athymic animals. The established human and murine cell lines were characterized by cytogenetic methods. Transformed murine cells were then continuously passaged in tissue culture. The transformed mouse fibroblasts proved to possess tumorigenicity in nude mice. In the case of SLu-derived mouse tumor cells, tumors also developed in the immunocompetent BALB/c mice using 1×10⁶ to 5×10⁶ tumor cells for SC transplantation.     

SU5416抑制胃癌生长和肝转移的实验研究

目的　研究血管内皮细胞生长因子抑制物SU5 4 16对裸鼠原位种植人胃癌生长和肝转移抑制作用 ,探讨其对癌细胞凋亡的影响。方法　建立人胃癌裸鼠原位种植转移模型 ,随机分为 4组。种植后第 1周开始 ,分别自腹腔注射生理盐水 (对照组 )、5 氟尿嘧啶 (30mg·kg-1·d-1,5 FU组 )、SU5 4 16(15mg·kg-1·d-1,SU5 4 16组 )、5 FU与SU5 4 16联合应用 (5 FU 30mg·kg-1·d-1,SU5 4 16 15mg·kg-1·d-1,5 FU +SU5 4 16组 ) ,每天 1次 ,共 7周。第 8周处死动物 ,测量原位肿瘤瘤重、抑瘤率、微血管密度(MVD)、胃癌细胞凋亡指数 (AI) ,观察肿瘤细胞肝转移情况。结果　对照组、5 FU组、SU5 4 16组、5 FU+SU5 4 16组的原位肿瘤瘤重分别为 (1.35± 0 .4 2 )、(0 .75± 0 .33)、(0 .34± 0 .14 )及 (0 .2 1± 0 .15 ) g ;抑瘤率分别为 4 4 .5 % ,79.3% ,84 .4 % ;肝转移率分别为 90 .0 % ,36 .4 % ,2 5 .0 % ,0 %。MVD分别为 14 .6± 5 .8,13.1± 4 .7,3.9± 1.8,2 .1± 1.5 ;AI分别为 (3.76± 2 .2 5 ) % ,(6 .81± 4 .92 ) % ,(9.82± 3.76 ) % ,(17.6 5± 9.85 ) %。与对照组、5 FU组相比 ,SU5 4 16组、5 FU +SU5 4 16组胃癌生长、肝转移及MVD受到明显抑制 (P <0 .0 5 ) ,AI明显增高 (P <0 .0 5 )。结论　SU     

人原发性直肠恶性淋巴瘤裸小鼠原位移植模型的建立及其生物学特性

目的:建立人原发性直肠恶性淋巴瘤裸小鼠原位移植模型,探讨其生物学特性.方法:采用人直肠原发性恶性淋巴瘤术中的新鲜瘤组织块植入裸鼠的直肠黏膜层内,观察原位移植的成瘤率,移植瘤的侵袭和转移率.进行形态学(光镜、电镜、免疫组织化学),染色体核型,流式细胞分析.结果:依据WHO新的分类标准,建成1株人直肠原发性(非霍奇金B细胞性)恶性淋巴瘤裸鼠原位移植模型HRBL-0305.移植瘤组织病理学为(非霍奇金B细胞性)高度恶性淋巴瘤;免疫组织化学示CD19,CD20,CD22,CD45阳性,CD3,CD7阴性.染色体众数56-69条,流式细胞DI值为1.57-1.61,均为异倍体.HRBL-0305已传至31代;共移植裸鼠187只.其肿瘤移植生长率和液氮冻存复苏成活率均为100.0%,肝转移率为45.4%,淋巴结和腹腔种植转移率均为38.0%,移植瘤在裸鼠的直肠内自主侵袭性生长,发生血液、淋巴转移和腹腔内种植性转移,移植瘤组织病理学,超微结构的观察,流式细胞DNA含量测定及染色体核型的分析,表明与人源直肠恶性淋巴瘤细胞相一致.结论:HRBL-0305是首次成功建立的人直肠原发性恶性淋巴瘤裸鼠原位移植模型,完整地重现了人直肠原发性恶性淋巴瘤的自然临床病理过程,且转移模式与临床患者相似,为研究直肠恶性淋巴瘤的生物学特性和治疗提供了理想动物模型平台.     

人胰腺癌原位移植模型MRI增强扫描特征及病理对照研究

目的 探讨人胰腺癌原位移植瘤模型的MRI影像学表现及其病理基础.方法 应用3.0T磁共振成像仪及临床型乳腺线圈对30只胰腺癌裸鼠原位模型行冠状位及横断位TSE-T1 WI/T2 WI平扫,经腹腔注射钆喷酸葡胺(Gd-DTPA)行连续动态增强扫描,测量平扫和增强扫描各时相肿瘤信号强度,计算强化率,分析MR图像特征并与病理对照.结果 30只裸鼠荷瘤接种成功率为100%,组织学检查符合胰腺低分化腺癌.与邻近组织信号相比,90%(27/30)肿瘤T1 WI呈均匀稍低信号,10%(3/30)信号欠均匀;80%(24/30)肿瘤T2 WI呈不均匀高信号、内见斑片状更高或等信号区,20%(6/30)呈均匀等高信号.平扫肿瘤信号强度为228.35±11.71,增强扫描后1.5、3、6,9、12 min的肿瘤信号强度分别为258.20±11.17、301.75±17.09、358.65±25.13、480.05±19.01、558.35±40.49,均明显高于平扫(P值均<0.01);各时相强化率分别为0.13±0.04、0.35±0.11、0.56±0.10、1.10±0.10、1.45±0.18,各时相间差异均有统计学意义(P值均<0.01).MR强化明显区为供血丰富的肿瘤生长活跃区域,中央无强化区为坏死组织和(或)肿瘤细胞致密且毛细血管较少区域.结论 经腹腔注射对比剂后可获得清晰的移植瘤MRI图像,与病理检查结果具有很好的一致性.     

Novel experimental models of human cancer metastasis in nude mice: Lung metastasis,intraabdominal carcinomatosis with ascites,and liver metastasis

Summary The ability of RPMI4788 cells, a human colon cancer cell line, to produce experimental metastases in the lung, intraperitoneal cavity, and liver was studied in nude mice. Injection of 2×10⁶ tumor cells into the tail vein of nude mice produced metastatic lung tumors, and an intraportal injection of 5×10⁶ cells produced metastatic liver tumors. An intraabdominal carcinomatosis with ascites was formed after an i.p. injection of 5×10⁶ tumor cells. The nude mice with lung metastasis or intraabdominal carcinomatosis always died within a few weeks. Macroscopic observation showed that the number of lung metastatic nodules on day 21 after tumor inoculation was 311.3±78.2 (mean±SD) in BALB/C nude mice, and 187.5±26.7 in ICR nude mice. In survival experiments, the mice with intraabdominal carcinomatosis showed a mean survival of 29.0±1.7 (mean±SD) days in BALB/C nude mice and 43.6±6.1 days in ICR nude mice. These novel experimental models of metastases in nude mice produced by injection of RPMI4788 cells had high reproducibility and may be useful not only for the study of the metastatic process but also for testing anticancer drugs.     

三羟基异黄酮诱导人胃癌原代细胞裸鼠移植瘤凋亡的研究

目的探讨三羟基异黄酮诱导人胃癌原代细胞裸鼠移植瘤凋亡的机制。方法建立人胃癌原代细胞裸鼠移植瘤模型并测定移植瘤的生长曲线;25只Balb/c裸鼠接种胃癌原代细胞悬液生成移植瘤后均分为五组,不同剂量的三羟基异黄酮(0.5、1.0和1.5mg/kg)、生理盐水和DMSO进行瘤旁注射,透射电镜和TUNEL法检测肿瘤组织凋亡情况,免疫组化法和RT-PCR法检测肿瘤组织凋亡相关基因bcl-2和bax的表达情况。结果三羟基异黄酮对胃癌原代细胞移植瘤有明显的抑制作用;透射电镜发现三羟基异黄酮导致移植瘤内大量细胞发生凋亡;TUNEL染色法发现三羟基异黄酮注射组瘤细胞的凋亡指数(28.7%±1.1%、33.4%±1.4%和37.1%±1.0%)明显高于生理盐水和DMSO对照组(P<0.05),而两个对照组(11.8%±0.4%和11.7%±0.4%)之间差异无统计学意义。免疫组化法发现三羟基异黄酮注射组的Bcl-2蛋白阳性细胞率(11.8%±0.9%、5.7%±0.8%和4.0%±0.8%)明显低于两个对照组(P<0.05),而两个对照组(19.5%±0.6%和17.6%±1.4%)之间差异无统计学意义;而Bax蛋白阳性细胞率(20.0%±1.2%、24.7%±0.9%和29.3%±1.6%)明显高于两个对照组(P<0.05),而两个对照组(10.3%±0.4%和10.9%±0.9%)间差异无统计学意义;RT-PCR法发现三羟基异黄酮注射组的bcl-2mRNA条带强度随剂量增大而递减,并明显低于对照组(P<0.05);而baxmRNA条带强度递增,并明显低于对照组(P<0.05),而两对照组间差异无统计学意义(P>0.05)。结论三羟基异黄酮对胃癌原代细胞移植瘤有明显的抑制作用,通过下调bcl-2和上调bax的表达而诱导胃癌裸鼠移植瘤细胞发生凋亡,是其抗胃癌作用的机制之一。     

Liver metastasis models of human colorectal carcinoma established in nude mice by orthotopic transplantation and their biologic characteristic

AIM To establish a liver metastasis model of human colorectal carcinoma in nude mice.METHODS Orthotopic transplantation of histologically intact colorectal tissues from patients into colorectal mucosa of nude mice. Tumorgenicity, invasion, metastasis and morphological characteristics of the transplanted tumors were studied by light microscopy, electron microscopy and immunohistochemistry.RESULTS Liver metastasis models of human colon carcinoma (HCA-HMN-1) and human rectal carcinoma (HRA-HMN-2) were established after screening from 34 colorectal carcinomas. They had been passaged in vivo for 18 and 21 generations respectively. There were lymphatic, hemotogenous and implanting metastasesis. CEA secretion was maintained after transplantation. The primary and liver metastatic tumors were similar to the original human carcinoma in histopathological and ultrastructural features, DNA content and chromosomal karyotype.CONCLUSION The liver metastasis models provide useful tools for the study of mechanism of metastasis and its treatment of human colorectal cancer.INTRUDUCTIONSome models of nude mice that fresh human colorectal carcinoma tissue or cells were successfully transplanted subcuteneously have been reported at home and abroad[1,2]. But until now there has been no report on a liver metastasis model of human colorectal carcinoma established by orthotopic transplantation in nude mice in China. Based on our previous models of human liver and pancreas carcinoma by orthotopic transplantation[3,4], we established liver metastasis models of colon and rectum carcinoma with a spontaneous metastasis rate of 100%.     

Effect of arsenic trioxide on vascular endothelial cell proliferation and expression of vascular endothelial growth factor receptors Flt-1 and KDR in gastric cancer in nude mice

AIM: To investigate the effect of arsenic trioxide (As2O3) on expression of vascular endothelial growth factor receptor-1 (VEGFR-1, Flt-1) and VEGFR-2 (KDR) in human gastric tumor cells and proliferation of vascular endothelial cells. METHODS: The solid tumor model was formed in nude mice with the gastric cancer cell line SGC-7901. The animals were treated with As2O3. Microvessel density (MVD) and expression of Flt-1 and KDR were detected by immunofluorescence laser confocal microscopy. SGC-7901 cells were treated respectively by exogenous recombinant human VEGF165 or VEGF165 As2O3. Cell viability was measured by MTT assay. Cell viability of ECV304 cells was measured by MTT assay, and cell cycle and apoptosis were analyzed using ? ow cytometry. RESULTS: The tumor growth inhibition was 30.33% and 50.85%, respectively, in mice treated with As2O3 2.5 and 5 mg/kg. MVD was signifi cantly lower in arsenic-treated mice than in the control group. The ? uorescence intensity levels of Flt-1 and KDR were significantly less in the arsenic-treated mice than in the control group. VEGF165 may accelerate growth of SGC7901 cells, but As2O3 may disturb the stimulating effect of VEGF165. ECV304 cell growth was suppressed by 76.51%, 71.09% and 61.49% after 48 h treatment with As2O3 at 0.5, 2.5 and 5 μmol/L, respectively. Early apoptosis in the As2O3- treated mice was 2.88-5.1 times higher than that in the controls, and late apoptosis was 1.17-1.67 times higherthan that in the controls. CONCLUSION: Our results showed that As2O3 delays tumor growth, inhibits MVD, down-regulates Flt-1 and KDR expression, and disturbs the stimulating effect of VEGF165 on the growth of SGC7901 cells. These results suggest that As2O3 might delay growth of gastric tumors through inhibiting the paracrine and autocrine pathways of VEGF/VEGFRs.