Models of human metastatic colon cancer in nude mice orthotopically constructed by using histologically intact patient specimens.

There is an important need for clinically relevant animal models for human cancers. Toward this goal, histologically intact human colon-cancer specimens derived surgically from patients were implanted orthotopically to the colon or cecum of nude mice. We have observed extensive orthotopic growth in 13 of 20 cases of implanted patient colon tumors. These showed various growth patterns with subsequent regional, lymph-node, and liver metastasis, as well as general abdominal carcinomatosis. Thus, models for human colon cancer have been developed that show (i) local growth, (ii) abdominal metastasis, (iii) general abdominal carcinomatosis with extensive peritoneal seeding, (iv) lymph-node metastasis, (v) liver metastasis, and (vi) colonic obstruction. These models permit the passage of the tumors to form large cohorts. They will facilitate research into the biology of colon cancer metastatic capability and the development of new drugs active against metastatic cancer. These models may also predict the clinical course and the in vivo response to drugs of the cancer of individual patients.     

A metastatic nude-mouse model of human pancreatic cancer constructed orthotopically with histologically intact patient specimens.

Pancreatic cancer is one of the most intractable and least understood of all human cancers. Pancreatic cancers is the fourth-leading cause of cancer-related mortality in the United States with less than 2% of the patients surviving for 5 yr. In an effort to help develop more effective treatment modalities for pancreatic cancer and improve detection, we report an animal model for individual human pancreatic-cancer patients. The model involves orthotopic transplantation of histologically intact pancreatic-cancer specimens to the nude-mouse pancreas, which can result in models that resemble the clinical picture including (i) extensive local tumor growth, (ii) extension of the locally growing human pancreatic cancer to the nude-mouse stomach and duodenum, (iii) metastases of the human pancreatic tumor to the nude-mouse liver and regional lymph nodes, and (iv) distant metastases of the human pancreatic tumor to the nude-mouse adrenal gland, diaphragm, and mediastinal lymph nodes. In a series of five patient cases, a 100% take rate has been demonstrated, and of 17 mice transplanted, 15 supported tumor growth. Immunohistochemical analysis of the antigenic phenotype of the transplanted human pancreatic tumors showed a similar pattern of expression of two different human tumor-associated antigens, such as tumor-associated glycoprotein 72 and carcinoembryonic antigen in the transplanted tumors when compared with the original surgical biopsy, suggesting similarity between the two. This model should, therefore, prove valuable for treatment evaluation of individual cancer patients, as well as for evaluation of experimental treatment modalities for this disease.     

人肝癌裸鼠移植模型的研究进展

肝癌的基础与临床研究迫切需要能真正模拟肝癌在人体内自然生长、侵袭及转移全部过程的动物模型.目前,人肝癌裸鼠移植模型是人体外最接近人类肝癌的整体实验模型,并且造模时间短,成功率高,按移植部位可以分为皮下移植、原位移植、腹腔移植以及转移模型.影响裸鼠移植模型建立的因素主要有人肝癌细胞或外科标本的特性、移植部位及移植癌细胞数量、裸鼠的品系和周龄以及生长环境和其他因素的影响.     

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     

Characterization of gastric cancer models from different cell lines orthotopically constructed using improved implantation techniques

AIM: To develop orthotopic gastric cancer mouse models from different cell lines and characterize the tumor features to assist further in preclinical trials and clinical treatment strategies.METHODS: Human gastric cancer SGC-7901 and BGC-823 cell suspensions were injected subcutaneously into nude mice to develop solid tumors, and tumor tissue pieces were then implanted under the serous coat of the stomach. An autopsy was performed on all animals of the SGC-7901 and BGC-823 models to observe the primary tumor growth and metastases using pathological and immunohistochemical methods.RESULTS: Both models showed large tumors in situ resulting in pressure and infiltration of the adjacent organs. The gastric cavity became smaller, along with stenosis of the cardia or pylorus. There were biological and statistical differences between the two models. The metastasis rate in involved organs (lymph nodes, kidney, spleen, testis) was significantly higher in the BGC-823 model compared to the SGC-7901 model (P < 0.05 or P < 0.01). The median survival of the BGC-823 model was shorter than that of SGC-7901 (23 d vs 84 d, P < 0.05). Histopathologically, the primary tumor and metastatic lesions of the two models showed obvious atypia and mucus in the cytoplasm. Compared with the SGC-7901 model, BGC-823 appeared more poorly differentiated (absence of adenoid structure), had a smaller volume, and richer capillary structure. Immunohistochemical staining revealed cytokeratin 20 and epithelial membrane antigen expression was positive in the SGC-7901 tumors, while negative in BGC-823 ones.CONCLUSION: Models using the SGC-7901 and BGC-823 cell lines were established which could function in gastric cancer research on carcinogenesis mechanism and drug discovery. The two models showed different tumor behavior and the latter was more malignant than the former.     

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。     

Microencapsulated tumor assay: evaluation of the nude mouse model of pancreatic cancer

AIM: To establish a more stable and accurate nude mouse model of pancreatic cancer using cancer cell microencapsulation.METHODS: The assay is based on microencapsulation technology, wherein human tumor cells are encapsulated in small microcapsules (approximately 420 μm in diameter) constructed of semipermeable membranes. We implemented two kinds of subcutaneous implantation models in nude mice using the injection of single tumor cells and encapsulated pancreatic tumor cells. The size of subcutaneously implanted tumors was observed on a weekly basis using two methods, and growth curves were generated from these data. The growth and metastasis of orthotopically injected single tumor cells and encapsulated pancreatic tumor cells were evaluated at four and eight weeks postimplantation by positron emission tomography-computed tomography scan and necropsy. The pancreatic tumor samples obtained from each method were then sent for pathological examination. We evaluated differences in the rates of tumor incidence and the presence of metastasis and variations in tumor volume and tumor weight in the cancer microcapsules vs single-cell suspensions.RESULTS: Sequential in vitro observations of the microcapsules showed that the cancer cells in microcapsules proliferated well and formed spheroids at days 4 to 6. Further in vitro culture resulted in bursting of the membrane of the microcapsules and cells deviated outward and continued to grow in flasks. The optimum injection time was found to be 5 d after tumor encapsulation. In the subcutaneous implantation model, there were no significant differences in terms of tumor volume between the encapsulated pancreatic tumor cells and cells alone and rate of tumor incidence. There was a significant difference in the rate of successful implantation between the cancer cell microencapsulation group and the single tumor-cell suspension group (100% vs 71.43%, respectively, P = 0.0489) in the orthotropic implantation model. The former method displayed an obvious advantage in tumor mass (4th wk: 0.0461 ± 0.0399 vs 0.0313 ± 0.021, t = -0.81, P = 0.4379; 8th wk: 0.1284 ± 0.0284 vs 0.0943 ± 0.0571, t = -2.28, respectively, P = 0.0457) compared with the latter in the orthotopic implantation model.CONCLUSION: Encapsulation of pancreatic tumor cells is a reliable method for establishing a pancreatic tumor animal model.     

OB glue paste technique for establishing nude mouse human gastric cancer orthotopic transplantation models

AIM： To establish nude mouse human gastric cancer orthotopic transplantation models using OB glue paste technique. METHODS： Using OB glue paste technique, orthtopic transplantation models were established by implanting SGC-7901 and NKN-45 human gastric cancer cell strains into the gastric wall of nude mice. Biological features, growth of the implanted tumors, the success rate of transplantation and the rate of auto-metastasis of the two models were observed. RESULTS： The success rates of orthotopic transplanration of the two models were 94.20% and 96%. The rates of hepatic metastasis, pulmonary metastasis, peritoneal metastasis, lymphocytic metastasis and splenic metastasis were 42.13% and 94.20%, 48.43% and 57.97%, 30.83% and 36.96%, 67.30% and 84.06%, and 59.75% and 10.53%, respectively. The occurrence of ascites was 47.80% and 36.96%. CONCLUSION： OB glue paste technique is easy to follow. The biological behaviors of the nude mouse human gastric cancer orthotopic transplantation models established with this technique are similar to the natural processes of growth and metastasis of human gastric cancer, and, therefore, can be used as an ideal model for experimental research of proliferative metastasis of tumors.     

Suppression of human nasopharyngeal carcinoma cell growth in nude mice by the wild-type p53 gene

Summary Wild-type and mutant human p53 genes were transfected into the nasopharyngeal carcinoma (NPC) cell line CNE-3. Tumorigenicity in nude mice showed that the tumor resulting from the cells transfected with the wild-type p53 gene grew more slowly and was smaller than that from the cells transfected with mutant p53 gene and that from control CNE-3 cells. In contrast, the tumor from the cells transfected with the mutant p53 gene grew faster than that produced by cells transfected with the wild-type p53 gene and that produced by control CNE-3 cells. The results demonstrate that the wild-type p53 gene could inhibit the NPC cell growth in nude mice and the mutant p53 gene could enhance the NPC cell growth in nude mice. The p53 gene may also play an important role in the pathogenesis of NPC.Abbreviation NPC nasopharyngeal carcinoma     

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.     

Anticancer activity of genistein on implanted tumor of human SG7901 cells in nude mice

AIM： To investigate genistein-induced apoptosis of implanted tumors of SG7901 cells in nude mice, and the relationship between this apoptosis and expression of Bcl-2 and Bax. METHODS： Establishing a transplanted tumor model by injecting human SG7901 cells into subcutaneous tissue of nude mice. Genistein （0.5, 1 and 1.5 mg/kg） was directly injected adjacent to the tumor, six times at 2-d intervals. Then, changes in tumor volume were measured continuously and tumor inhibition rate of each group was calculated. We observed the morphological alterations by transmission electron microscopy （TEN）, measured the apoptotic rate by the TUNEL staining method, and detected the expression of apoptosisregulated gene Bcl-2 and bax by immunohistochemical staining and RT-PCR. RESULTS： Genistein 0.5, 1 and 1.5 mg/kg significantly inhibited carcinoma growth when it was injected near the tumor by 10.8%, 29.9% and 39.6%, respectively. Genistein induced implanted tumor cells to undergo apoptosis, with apoptotic characteristics seen by TEM. The apoptosis index was increased progressively with increasing genistein dose （28.9% ± 1.2%, 33.8% ±1.6% and 37.7% ±1.2%）. The positive rate of Bcl-2 protein was decreased progressively （11.9%± 0.9%, 5.9%± 0.7% and 4.2% ±0.6%）, and the positive rate of bax protein was increased progressively （0.9% ±1.7%, 24.9% ±0.8% and 29.6% ± 1.7%） by immunohistochemical staining, with increasing dose of genistein. The density of Bcl-2 mRNA decreased progressively and the density of bax mRNA increased progressively with elongation of time by RT-PCR. CONCLUSION： Genistein was able to induce apoptosisof transplanted tumor cells. This apoptosis may be mediated by down-regulation of the apoptosis-regulated gene Bcl-2 and up-regulation of apoptosis-regulated gene bax.     

Metastatic human hepatocellular carcinoma models in nude mice and cell line with metastatic potential

Metastatic human HCC model is needed for the studies onmechanism and intervention of metastatic recurrence,Byusing orthotopic implantation of histologically intacttissues of 30 surgical specimens,a patient-likemetastatic model of human HCC in nude mice (LCI-D20)and a low metastatic model of human HCC in nude mice(LCI-D35) have been established.All mice withtransplanted LCI-D20 tumors exhibited extremely highmetastatic ability including spontaneous metastasis toliver,lungs,lymph nodes and peritoneal seeding.Remarkable difference was also found in expression ofsome of the invasiveness related genes and growthfactors between the LCI-D20 and LCI-D35 tumors.PAI-1increased gradually following tumor progression in LCI-D20 model,and correlated with tumor size and AFP level.Phasic expression of tissue intercellular adhesionmolecule-1 in this model was also observed.Using cornealmicropocket model,it was demonstrated that the vascularresponse induced by LCI-D20 tumor was stronger than thatinduced by LCI-D35 tumor.Similar report on metastatichuman HCC model in nude mice and human HCC cell linewith metastatic potential was rarely found in theliterature.This LCI-D20 model has been widely used forthe studies on intervention of metastasis,including anti-angiogenesis,antisense approach,metalloproteinaseinhibitor,differentiation inducer,etc.It is concluded thatthe establishment of metastatic human HCC model in nudemice and human HCC cell line with metastatic potentialwill provide important models for the in vivo and in vitrostudy of HCC invasiveness,angiogenesis as well asintervention of HCC recurrence.     

Inhibitory effect of the angiogenesis inhibitor TNP-470 on tumor growth and metastasis in nude mice bearing human hepatocellular carcinoma

The antitumor and anti-metastatic effects of a potent angiogenesis inhibitor,O-(chloroacetyl-carbamoyl)fumagillol (TNP-470), was investigated in a highly metastatic model of human hepatocellular carcinoma—LCI-D20. Small pieces of LCI-D20 tumor tissue were implanted subcutaneously into the right axillary region of 24 nude mice; the mice were then randomized into two groups. To one group, TNP-470 30 mg/kg was given as a subcutaneous injection every other day from day 1 to day 15 and the mice were sacrificed on day 26. An antitumor effect of TNP-470 was clearly demonstrated by tumor weight (0.97±0.34 g compared to 2.04±0.34 g,P<0.001) and -Fetoprotein value (93±59 g/L compared to 769±282 g/L,P<0.001). There was also an anti-metastatic effect of TNP-470. Lung metastases developed in only 1 of 12 mice in the treated group, while they developed in 6 of mice of the control group. No severe side-effect of TNP-470 was found in this study. In vitro study revealed that the purified hepatoma cells were insensitive to TNP-470 (the 50% inhibitory concentration was 43 g/ml). These results suggest that the angiogenesis inhibitor TNP-470 has both strong antitumor and anti-metastatic effects on a human hepatocellular carcinoma model in nude mice.Abbreviations TNP-470 O-(chloroacetyl-carbamoyl) Fumagillol - MTT 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide This work was partly supported by the CHina Medical Board of New York, grant 93-583, and a Leading Speciality grant of Shanghai Health Bureau     

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     

人结肠癌裸鼠移植瘤细胞动力学与雌孕激素受体研究

将人结肠癌异种移植于ＢＡＬＢ／ｃｎｕ／ｎｕ系无胸腺裸鼠并传５代。对原结肠癌及各代移植瘤进行病理学、组化、细胞动力学与电镜检查。应用流式细胞仪（ＦＣＭ）与生化葡聚糖包裹活性碳吸附法（ＤＣＣ）对各代移植瘤进行胞核ＤＮＡ倍体与雌孕激素受体（ＥＲ·ＰＲ）检测，并与原人结肠癌比较，结果显示：各代移植瘤均保持原人结肠癌相同的病理学特征、阳性雌孕激素受体表达及稳定的胞核ＤＮＡ倍体。就受体作用失常参与大肠癌发病机制进行讨论，为动态观察性激素受体变化规律及从实验药理学探讨内分泌治疗的真正价值提供依据     

西咪替丁抑制人肠癌裸鼠移植瘤

目的：研究西咪替丁对人结肠癌裸鼠移植瘤生长的抑制作用及机制。方法：建立人结肠癌裸鼠皮下移植瘤模型。随机分2组,每组5只实验鼠。肿瘤种植前3 d开始分别皮下注射生理盐水(对照组)或西咪替丁(治疗组),每天1次,观察成瘤时间及瘤体成长情况。肿瘤种植后第7周处死实验鼠,测定瘤体大小,并用免疫组化方法测定肿瘤组织内微血管密度(MVD)和血管内皮生长因子(VEGF)的表达。结果：治疗组肿瘤体积明显小于对照组;治疗组肿瘤组织中的VEGF表达程度和MVD计数亦明显低于对照组。结论：西咪替丁通过抑制VEGF表达,减少血管生成,从而抑制肿瘤生长。     

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.