THE ESTABLISHMENT OF A NEW ANIMAL MODEL FOR GASTRIC CANCER STUDY BY ORTHOTO PIC IMPLANTATION OF GASTRIC CANCER CELLS INTO ATHYMIC NUDE MICE

An animal model mimicking human gastric cancer by gastric wall implantation technique in athymic nude mice was reported. Two human gastric cancer cell lines. MKN-45 and MKN-28, were used in this study. All animals with gastric wall implantation of cancer cells of these two cell lines developed grossly visible gastric tumors after 3-4 weeks of implantation. Histopathological examination showed that tumors prirnarily grew at serosal side of stomach, and progressively invaded the gastric mucosa, but none showed metastasis in this study. All tumor-bearing animals died within 5-8 weeks after implantation. These results indicated that gastric wall of nude mice provided a good soil for growth and propagation of human gastric cancer cells. The model was useful for in vivo study on biological behavior of various types of human gastric cancers.

How can we establish animal models of HIV-associated lymphoma?

Human immunodeficiency virus(HIV)infection is strongly associated with a height-ened incidence of lymphomas.To mirror the natural course of human HIV infection,animal models have been developed.These models serve as valuable tools to inves-tigate disease pathobiology,assess antiretroviral and immunomodulatory drugs,ex-plore viral reservoirs,and develop eradication strategies.However,there are currently no validated in vivo models of HIV-associated lymphoma(HAL),hampering progress in this crucial domain,and scant attention has been given to developing animal models dedicated to studying HAL,despite their pivotal role in advancing knowledge.This re-view provides a comprehensive overview of the existing animal models of HAL,which may enhance our understanding of the underlying pathogenesis and approaches for malignancies linked to HIV infection.

Targeting Effect Study of ￣(3) H-Mitoxantrone Nanosphereson Hepatocellular Carcinoma(HCC) Model in Nude Mice

The distribution of ￣(3)H-mitoxantrone polybutyl cyanoacrylate nanospheres(￣(3)H-DHAQ-PBCA-NS)in the viscera,muscle and tumors of human hepatocellular carcinoma (HCC)model in nude mice was studied with liquid scintillation counting techniique. The results showed that the ￣(3)H-DHAQ-PBCA-NS had remarkable liver targeting effect. The content of ￣(3)H-DHAQ-PBCA-NSin liver and heterotopic liver tumor was found to be 71.31±10. 49% of total amount of drug in animal body. It was also found that the content of ￣(3)H-DHAQ-PBCA-NS in liver was higher than that in liver tissue, and the content of ￣(3)H-DHAQ-PBCA-NS in annpit tumor was higher than that in armpit muscle tissue,but had no significant difference;It provides an ideal preparation for the DHAQ admini-stration.

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 apoptosis-regulated 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 morphologicalchanges 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 in each group was to be found and the density of bax mRNA was increased progressively with increase of dose of bufalin by RT-PCR. CONCLUSION: Bufalin has significant anti-tumor activities in the orthotopic transplantation tumor model of human hepatocellular carcinoma in nude mice with no marked toxicity and was able to induce apoptosis of transplanted tumor cells. This apoptosis may be mediated mainly via up-regulating the expression of apoptosis-regulated gene bax, which may be involved in its anti-tumor mechanism of bufalin.

Establishment of a mdr1 Multidrug Resistant Model of Orthotopic Transplantation of Liver Carcinoma on Nude Mice

To develop a new method of inducing mdrl multidrug resistance by establishinga nude mice model of orthotopic transplantation of liver carcinoma by sporadic abdominalchemotherapy at intervals. Methods: Hepatocellular carcinoma HepG2 cell was cultured and injectedsubcutaneously to form the tumor-supplying mice. The tumor bits from the tumor-supplying mice wereimplanted under the envelope of the mice liver and induced by abdominal chemotherapy withPharmorubicin. Physical examination, ultrasonography, spiral CT and operative inspection were usedto examine tumor progression. RT-PCR and immunohistochemistry were adopted to detect the expressionof mdr1-mRNA and its encoded protein P-gp protein (P-gp). Results: There was no operative dead, therate of implanting tumor successfully was 88% (22/25), the rate of implanting secondly successfullywas 100% (3/3), and the rate of inducing successfully was 80% (16/20). The expression of mdrl-mRNAand the P-gp in the inducing group was 23 folds and 13 folds in the control group respectively.Conclusion: We have established an in vivo model of mdr using nude mice transplanted with orthotopicliver neoplasm coupled to chemotherapy.

Anti-tumor effect of bufalin on the orthotopic transplantation tumor model of human hepatocellular carcinoma in nude mice

Objective: To investigate anti-tumor effect of bufalin on 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 in nude mice by subcutaneous injection. Then the subcutaneous tumors were implanted into the liver of nude mice, and the orthotopic transplantation tumor models of human hepatocellular carcinoma were established. Seventy-five models were randomized into 5 groups ( n = 15) . Bufalin was injected intraperitoneally into the 3 groups at dose of 1.5,1 and 0.5 mg/kg for day 15 - 24, respectively. NS group were injected equal volume saline as above and adriamycin were injected intraperitoneally into ADM group at dose of 8.0 mg/kg for day 15. Ten mice in each group were killed at day 25 and detected on morphological and ultrastructural changes in myocardium, brain, liver, kidney and tumor tissues by pathology and electron microscope. The survival time in each group were observed. Results: The tumor volumes in each group of bufalin were reduced significantly compared with NS group (P < 0.01), the survival time were prolonged in group Bu 1 and Bu 2 compared with NS group ( P < 0.05), and tumor tissues were mainly necrosis in severe or moderate degree in Bu 1, Bu 2 groups, and mild degree or moderate degree in Bu 3 group. No morphological changes were detected in myocardium, brain, liver and kidney tissues, respectively. Apoptotic characteristics could be seen in tumor tissues of group Bu 1 and group Bu 2. Conclusion: Bufalin has significant anti-tumor effects on the orthotopic transplantation tumor model of human hepatocellular carcinoma in nude mice without marked toxicity. To guide cell apoptosis may be one of its anti-tumor mechanism of bufalin.

Establishment of orthotopic impact/metastasis model of human ovary cancer in nude mice

Objective: To establish a patient-like human ovary carcinoma /spontaneous metastasis model using orthotopic transplanation of histologically intact tumor tissue. Methods: An highly metastatic ovarian tumor line (HO-8910PM: Human serum carcinoma of the ovary )previously grown substaneously was transplanted into the ovicapsule using microsurgery technique .Histologically intact human ovary tumor pieces gained from implantation site were passaged between ovicapsules for four generations. Results: All mice developed ovary tumors and the metastatic rates were about 75%. The tumors only metastasized to liver but no other organs. The earliest appearance of metastasis was 14 d and the average survival period was 20.7±4.89 d.The microscopic appearance of the metastases was similar to the tumor observed in the substaneous xenografts and orthotopically transplanted. Chromosomes analysis exhibited the feature of human carcinoma and retained genetic stability during the processes of passage. Conclusion: Orthotopic implanation provides a suitable micro-enviroment in which ovarian cancer can express its intrinsic clinically-relevant properties. This approach is relevant to the spontaneous development of ovarian cancer and is thought to be a useful model for studies of metastatic mechanism and therapy for ovary cancer.

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

Metastatic human HCC model is needed for the studies on mechanism and intervention of metastatic recurrence. By using orthotopic implantation of histologically intact tissues of 30 surgical specimens, a patient-like metastatic 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 with transplanted LCI-D20 tumors exhibited extremely high metastatic ability including spontaneous metastasis to liver, lungs, lymph nodes and peritoneal seeding. Remarkable difference was also found in expression of some of the invasiveness related genes and growth factors between the LCI-D20 and LCI-D35 tumors. PAI-1 increased gradually following tumor progression in LCI-D20 model, and correlated with tumor size and AFP level. Phasic expression of tissue intercellular adhesion molecule-1 in this model was also observed. Using corneal micropocket model, it was demonstrated that the vascular response induced by LCI-D20 tumor was stronger than that induced by LCI-D35 tumor. Similar report on metastatic human HCC model in nude mice and human HCC cell line with metastatic potential was rarely found in the literature. This LCI-D20 model has been widely used for the studies on intervention of metastasis, including anti-angiogenesis,antisense approach, metalloproteinase inhibitor, differentiation inducer, etc. It is concluded that the establishment of metastatic human HCC model in nude mice and human HCC cell line with metastatic potential will provide important models for the in vitro and in vitro study of HCC invasiveness, angiogenesis as well as intervention of HCC recurrence.

Effects of epidermal growth factor on the growth of human gastric cancer cell and the implanted tumor of nude mice

AIM: Epidermal growth factor (EGF) plays an important role in the regulation of gastrointestinal tissue growth and development, and it can stimulate epithelial proliferation, cell differentiation and growth. It has been established that the EGF can promote gastric cytoprotection and ulcer healing. But the potential ability of EGF to regulate the gastric cancer growth is unknown. This study is to investigate the influence of EGF on human gastric cancer cell and the implanted tumor growth of nude mice. METHODS: The cell growth rates of human gastric adenocarcinoma cell lines MKN-28, MKN-45, SGC-7901 and normal human gastric epithelial cells 3T3 were assessed when incubated with recombinant human EGF (rhEGF, 0.05, 0.1, 0.5, 1.0, 10, 50, 100 mg.L(-1)) using MTT method. The cells of MKN-28, MKN-45, SGC-7901 (gastric cancer tissue 1.5mm(3)) were implanted in the BALB/cA nude mice for 10 days.The EGF was given intraperitoneally (15, 30, 60 microg.kg(-1)) for 3 weeks. The body weights of the tumor-bearing animals and their tumor mass were measured afterwards to assess the mitogenic effect of rhEGF in the nude mice. RESULTS: Within the concentration range of 0.05-100mg.L(-1), rhEGF could increase the cell growth of normal 3T3 cells (cell growth rate 100% vs 102.8%, P【0.05), but partially restrain the gastric cancer cell growth. The latter effect was related to cell differentiation. In 15-60 microg/kg rhEGF groups, the mean implanted tumor mass of MKN-28 cell were 1.75 g, 1.91 g, 2.08 g/NS group 1.97 g (P】0.05), the mean tumor mass of SGC-7901 cell were 1.53 g, 1.07 g, 1.20 g/NS group 1.07 g (P】0.05), and for MKN-45 cell, the tumor mass were respectively 1.92 g, 1.29 g, 1.77 /NS group 1.82 g (P】0.05). So rhEGF had no obvious effect on implanted MKN-28, SGC-7901 and MKN-45 tumor growth. CONCLUSION: EGF has no stimulating effect on the human gastric cancer cell growth neither in vitro nor in vivo.

Effects of endostatin on expression of vascular endothelial growth factor and its receptors and neovascularization in colonic carcinoma implanted in nude mice

AIM:To investigate the antiangiogenic effects of endostatin on colonic carcinoma cell line implanted in nude mice and its mechanism. METHODS:Nude mice underwent subcutaneous injection with LS-174t colonic carcinoma cell line to generate carcinoma and were randomly separated into two groups.Mice received injection of vehicle or endostatin every day for two weeks. After the tumor was harvested,the tumor volumes were determined,and the expressions of CD34,VEGF and FIk-1 were examined by immunohistochemical method. RESULTS:Tumor volume was significantly inhibited in the endostatin group(84.17%)and tumor weight was significantly inhibited in the endostatin group(0.197±0.049) compared to the control group(1.198±0.105)(F=22.56, P=0.001),microvessel density(MVD)was significantly decreased in the treated group(31.857±3.515)compared to the control group(100.143±4.290)(F=151.62,P<0.001). Furthermore,the expression of FIk-1 was significantly inhibited in the treated group(34.29%) ompared to the control group(8.57%)(X^2=13.745,P=0.001).However no significant decrease was observed in the expression of vascular endothelial growth factor(VEGF)between these two groups(X^2=0.119,P=0.730). CONCLUSION:Endostatin can inhibit tumor growth and angiogenesis by blocking Vegf/FIk-1 pathway.This experiment provides the theory basis for developing a new anti-carcinoma drug through studying the properties of anti-angiogenesis inhibitors.

Tumor radioimmunoimaging of chimeric antibody in nude mice with hepatoma xenograft

IM To study the radioimmunoimaging (RAII) using the human/mouse chimeric Ab to evaluate its targeting activity in animal models.METHODS To chimeric Ab was labeled with 131I. RAII was performed at different intervals after injection of radiolabeled Abs in nude mice with human hepatoma xenograft, and tissue distribution of radioactivity was measured. Comparison was made in the chimeric Ab between the single segment Ab and previous murine mAb against HBxAg.RESULTS The experimental objects developed tumorpositive image after 2 days of radiolabeled Abs injection, and the peak accumulation of radioactivity fell on the 7th day. The tumor/liver ratioactivity of the chimeric Ab, single segment Ab, antiHBx mAb, and the control group was 281±021, 244±016, 460±019, and 096±014, respectively.CONCLUSION The genetic engineering Abs have a considerable targeting activity which can be used as a novel humanized vector in the targeting treatment of liver cancer..

The role of the gut microbiota on animal model reproducibility

The gut microbiota is composed of approximately 10^(10)-10^(14) cells, including fungi,bacteria, archaea, protozoa, viruses, and bacteriophages; their genes and their various metabolites were found throughout the gastrointestinal tract. It has co-evolved with each species to assist with day to day bodily functions, such as digestion,metabolism of xenobiotics, development of mucosal immunity and immunomodulation, and protection against invading pathogens. Because of the significant beneficial impact that gut microbiota may have, there is interest in learning more about it and translating these findings into clinical therapies. Results from recent studies characterizing the gut microbiota of various species have demonstrated the range of influences that may affect gut microbiota diversity, including animal strain, obesity, types of enrichment used, bedding and housing methods, treatment with antimicrobials,vendor source, specific animal housing, diet, and intercurrent disease. Relatively little is known about the functional consequences of alterations of the gut microbiota and exactly how changes in richness and diversity of the microbiota translate into changes in health and susceptibility to disease. Furthermore, questions have been raised as to whether germ-free or even ultraclean, barrier-raised mice are relevant models of human disease, given their significantly reduced gut microbiota diversity and complexity compared with conventionally housed mice. In addition, evidence suggests that the specific anatomical location selected for assessing the gut microbiota has a highly significant effect on study outcomes, in that bacterial phyla change significantly along the gastrointestinal tract. This paper will explore animal model reproducibility in light of this information about the gut microbiota.

Intravesical Instillation in Pure Line LEW Rats and Nude Mice

In order to study bladder intravesical instillation methods in pure line LEW rats and nude mice, female LEW rats and nude mice aged 2 to 4 weeks were sacrificed. Their urethra and bladder were observed under anatomical microscopy. A trochar was prepared according to the outline and an- gle of the urethra. Ink was poured into female rats and nude mice bladder though urethra. Filling and staining of bladder were observed and evaluated under anatomical microscopy. Status and urethral injury of rats and mice were observed. The results showed that urethra anatomic structure of rats and nude mice was different from that of human urethra. When bladder was filled with ink and became blue, liquid was not seen to leak out. The success rate of intubation was high (100%). Living activi- ties of animals weren’t influenced by intravesical instillation. It was concluded that bladder irrigation might be a kind of valid and utilizable method in pure line rat and nude mouse empirical study. The model may be a more effective tool for study of bladder tumor.

Advances in Animal Models of Hepatitis B Virus Infection

Hepatitis B virus (HBV) infection seriously affects human health. Stable and reliable animal models of HBV infection bear significance in studying pathogenesis of this health condition and development of intervention measures. HBV exhibits high specificity for hosts, and chimpanzee is long used as sole animal model of HBV infection. However, use of chimpanzees is strictly constrained because of ethical reasons. Many methods were used to establish small-animal models of HBV infection. Tupaia is the only nonprimate animalthat can be infected by HBV. Use of HBV-related duck hepatitis virus and marmot hepatitis virus infection model contributed to evaluation of mechanism of HBV replication and HBV treatment methods. In recent years, development of human–mouse chimeric model provided possibility of using common experimental animals to carry out HBV research.These models feature their own advantages and disadvantages and can be complementary in some ways. This

Incubation and application of transgenic green fluorescent nude mice in visualization studies on glioma tissue remodeling

Background The primary reasons for local recurrence and therapeutic failure in the treatment of malignant gliomas are the invasion and interactions of tumor cells with surrounding normal brain cells. However, these tumor cells are hard to be visualized directly in histopathological preparations, or in experimental glioma models. Therefore, we developed an experimental human dual-color in vivo glioma model, which made tracking solitary invasive glioma cells possible, for the purpose of visualizing the interactions between red fluorescence labeled human glioma cells and host brain cells. This may offer references for further studying the roles of tumor microenvironment during glioma tissue remodeling. Methods Transgenic female C57BL/6 mice expressing enhanced green fluorescent protein （EGFP） were crossed with male Balb/c nude mice. Then sib mating was allowed to occur continuously in order to establish an inbred nude mice strain with 50% of their offspring that are EGFP positive. Human glioma cell lines U87-MG and SU3 were transfected with red fluorescent protein （RFP） gene, and a rat C6 glioma cell line was stained directly with CM-Dil, to establish three glioma cell lines emitting red fluorescence （SU3-RFP, U87-RFP, and C6-CM-Dil）. Red fluorescence tumor cells were inoculated via intra-cerebral injection into caudate nucleus of the EGFP nude mice. Tumor-bearing mice were sacrificed when their clinical symptoms appeared, and the whole brain was harvested and snap frozen for further analysis. Confocal laser scanning microscopy was performed to monitor the mutual interactions between tumor cells and host brain cells. Results Almost all the essential tissues of the established EGFP athymic Balb/c nude mice, except hair and erythrocytes, fluoresced green under excitation using a blue light-emitting flashlight with a central peak of 470 nm, approximately 50% of the offsprings were nu/nu EGFP＋. SU3-RFP, U87-RFP, and C6-CM-Dil almost 100% expressed red fluorescence under the fluorescence microscope. Under fluorescence microscopic view, RFP＋ cells were observed growing wherever they arrived at, locating in the brain parenchyma, ventricles, and para-vascular region. The interactions between the transplanted tumor cells and host adjacent cells could be classified into three types： （1） interweaving; （2） mergence; and （3） fusion. Interweaving was observed in the early stage of tumor remodeling, in which both transplantable tumor cells and host cells were observed scattered in the tumor invading and spreading area without organic connections. Mergence was defined as mutual interactions between tumor cells and host stroma during tumorigenesis. Direct cell fusion between transplantable tumor cells and host cells could be observed occasionally. Conclusions This study showed that self-established EGFP athymic nude mice offered the possibility of visualizing tumorigenesis of human xenograft tumor, and the dual-color xenograft glioma model was of considerable utility in studying the process of tumor remodeling. Based on this platform, mutual interactions between glioma cells and host tissues could be observed directly to further elucidate the development of tumor microenvironment.

Establishment of a humanized ST6GAL1 mouse model for influenza research

Background:This study aimed to construct and characterize a humanized influenza mouse model expressing hST6GAL1.Methods:Humanized fragments,consisting of the endothelial cell-specific K18 promoter,human ST6GAL1-encoding gene,and luciferase gene,were microinjected into the fertilized eggs of mice.The manipulated embryos were transferred into the oviducts of pseudopregnant female mice.The offspring were identified using PCR.Mice exhibiting elevated expression of the hST6GAL1 gene were selectively bred for propagation,and in vivo analysis was performed for screening.Expression of the humanized gene was tested by performing immunohistochemical(IHC)analysis.Hematologic and biochemical analyses using the whole blood and serum of humanized hST6GAL1 mice were performed.Results:Successful integration of the human ST6GAL1 gene into the mouse genome led to the overexpression of human SiaT ST6GAL1.Seven mice were identified as carrying copies of the humanized gene,and the in vivo analysis indicated that hST6GAL1gene expression in positive mice mirrored influenza virus infection characteristics.The IHC results revealed that hST6GAL1 was expressed in the lungs of humanized mice.Moreover,the hematologic and biochemical parameters of the positive mice were within the normal range.Conclusion:A humanized influenza mouse model expressing the hST6GAL1 gene was successfully established and characterized.

Liver chimeric mice with tupaia hepatocyte transplantation as an animal model for hepatitis B virus infection and antiviral therapy

The human liver chimeric mouse is a milestone animal model for hepatitis B virus(HBV)infection.Such mice with primary human hepatocyte(PHH)transplantation are adequate to support chronic HBV infection for several weeks and to evaluate antiviral drugs.However,the drawbacks of PHHs include lack of available donors,poor expansion in vitro and ethical issues that limit the application of human liver chimeric mice,necessitating the search for alternatives.Here,we transplanted primary tupaia hepatocytes(PTHs)into the livers of immunodeficient mice and achieved high liver chimerism within six weeks.These tupaia liver chimeric mice are adequate to support chronic infection of the four common HBV genotypes A,B,C and D for 36 weeks,as well as evaluate of antiviral drugs,including hepatitis B immune globulin(HBIG),monoclonal antibody and nucleoside analogues(NAs),for preventative therapy and treatment post infection.In conclusion,the tupaia liver chimeric mouse model provides a convenient,efficient and stable animal model for chronic HBV infection and long-term drug evaluation.

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.

Establishment of an orthotopic transplantation tumor model of hepatocellular carcinoma in mice

AIM:To improve the outcome of orthotopic transplantation in a mouse model,we used an absorbable gelatin sponge(AGS) in nude mice to establish an orthotopic implantation tumor model.METHODS:MHCC-97L hepatocellular carcinoma(HCC)cells stably expressing the luciferase gene were injected into the subcutaneous region of nude mice.One week later,the ectopic tumors were harvested and transplanted into the left liver lobe of nude mice.The AGS was used to establish the nude mouse orthotopic implantation tumor model.The tumor suppressor gene,paired box gene 5(PAX5),which is a tumor suppressor in HCC,was transfected into HCC cells to validate the model.Tumor growth was measured by bioluminescence imaging technology.Semi-quantitative reverse transcription polymerase chain reaction(RT-PCR) and histopathology were used to confirm the tumorigenicity of the implanted tumor from the MHCC-97L cell line.RESULTS:We successfully developed an orthotopic transplantation tumor model in nude mice with the use of an AGS.The success rate of tumor transplantation was improved from 60% in the control group to 100% in the experimental group using AGS.The detection of fluorescent signals showed that tumors grew in all live nude mice.The mice were divided into 3 groups:AGS-,AGS+/PAX5-and AGS+/PAX5 +.Tumor size was significantly smaller in PAX5 transfected nude mice compared to control mice(P < 0.0001).These fluorescent signal results were consistent with observations made during surgery.Pathologic examination further confirmed that the tissues from the ectopic tumor were HCC.Results from RT-PCR proved that the HCC originated from MHCC-97L cells.CONCLUSION:Using an AGS is a convenient and efficient way of establishing an indirect orthotopic liver transplantation tumor model with a high success rate.