Animals ; Breast Diseases ; chemically induced ; Disease Models, Animal ; Female ; Mammary Neoplasms, Experimental ; chemically induced

BACKGROUNDIt is generally accepted that spleen plays a complex role in the tumor immunity, which would change in the different periods of cancer. In this study, we investigated the changes in the function of splenic macrophage (Mphi) in different stages of liver cancer induced by diethylnitrosamine (DEN) in rats. The aim was to support the characteristics of "two-way" and "phase" of spleen in tumor immunity.

METHODSThe model of pulmonary metastasis of liver cancer was established in forty male SD rats by DEN. In the 8th, 13th and 16th week, 10 rats were randomly chosen and sacrificed, and divided into cirrhosis, liver cancer and pulmonary metastasis groups depending on the pathological result, respectively. The other 10 rats were taken as control group. The Mphi was isolated by anchoring cultivation. The changes in ultrastructure, phagocytosis, cytokine secretion, antigen processing and presenting, and viability of splenic Mphi were detected by transmission electron microscopy, Vybrant(TM) Phagocytosis Assay, DQ(TM) Ovalbumin, and rat TNF-alpha ELISpot kits.

RESULTSUnder the electron microscope, the Mphi in the control group had some pseudopodium-like prominences, and mitochondria, ribosome, rough endoplasmic reticulum, lysosome can be found in the cytoplasm, and phagocytized RBC. In the liver cirrhosis and liver cancer group, Mphi had more prominences, meanwhile much more mitochondria, ribosome, rough endoplasmic reticulum, lysosome can be found in the cytoplasm, especially in the liver cancer group. In the pulmonary metastasis group, the Mphi was swelling, with few organelle. As compared to the control group, the function of splenic Mphi increased in cirrhosis and cancer groups, but decreased in metastasis group (phagocytosis rate: (84.7 +/- 1.9)%, (89.5 +/- 3.1)%, and (36.0 +/- 2.6)% vs (75.6 +/- 1.7)%, P < 0.05, P < 0.01; viability: (1.53 +/- 0.15)%, (1. +/- 0.14)%, and (1.12 +/- 0.29)% vs (1.48 +/- 0.17)%, P < 0.05, P < 0.01; TNF-alpha secretion: (741.0 +/- 52.9)%, (1126.2 +/- 174.5)%, and (313.8 +/- 50.8)% vs (626.6 +/- 24.6)%, P < 0.05, P < 0.01; positive cell rate of antigen processing and presenting: (24.03 +/- 1.87)%, (27.95 +/- 2.63)%, and (10.46 +/- 2.16)% vs (16.45 +/- 1.86)%, P < 0.01).

CONCLUSIONSIn the stage of cirrhosis and early cancer, the immune functions of splenic Mphi were reinforced. It may promote the non-specificity tumor immunity. On opposite, in the stage of pulmonary metastasis, the immune functions of splenic Mphi were impaired. It may lead to the decrease of tumor immunity.

Animals ; Cells, Cultured ; Diethylnitrosamine ; toxicity ; Disease Models, Animal ; Liver Cirrhosis ; immunology ; pathology ; Liver Neoplasms, Experimental ; chemically induced ; complications ; immunology ; ultrastructure ; Lung Neoplasms ; immunology ; secondary ; ultrastructure ; Macrophages ; pathology ; ultrastructure ; Male ; Microscopy, Electron, Transmission ; Rats ; Rats, Sprague-Dawley ; Spleen ; pathology ; ultrastructure

To study the effects of Smad4 on liver fibrosis and hepatocarcinogenesis in mice treated with CCl(4)/ethanol. The wild-type mice (Smad4 +/+) and the Smad4 knockout mice (Smad4 +/-) were injected subcutaneously with carbon tetrachloride(CCl(4))/ethanol twice a week for twenty weeks. The expression of Smad4, TGFbeta1, Smad2, Smad3, Smad6, TIMP1, MMP2 and MMP9 was detected by RT-PCR. In the cirrhotic liver, the expression of Smad4 mRNA was significantly higher than that in the normal liver. Comparing with wild-type mice (Smad4 +/+), the TGFbeta1-Smad4 signaling was markedly attenuated in the Smad4 knockout mice (Smad4 +/-). After induction by CCl(4)/ethanol, the hepatic fibrosis in the Smad4 knockout mice (Smad4 +/-) was obviously alleviated compared with the wild-type mice (Smad4 +/+), and the incidence rate of hepatocarcinogenesis of the former was also lower than that of the latter(32.0% vs 41.9%). These results indicate that knocking out Smad4 can delay the progression of liver fibrosis and liver cancer.
Animals ; Carbon Tetrachloride ; administration & dosage ; Disease Models, Animal ; Ethanol ; administration & dosage ; Female ; Liver Cirrhosis, Experimental ; chemically induced ; metabolism ; pathology ; Liver Neoplasms, Experimental ; chemically induced ; metabolism ; pathology ; Male ; Mice ; Mice, Knockout ; RNA, Messenger ; genetics ; metabolism ; Reverse Transcriptase Polymerase Chain Reaction ; Signal Transduction ; Smad Proteins ; genetics ; metabolism ; Smad4 Protein ; genetics ; metabolism ; Tissue Inhibitor of Metalloproteinase-1 ; genetics ; metabolism ; Transforming Growth Factor beta1 ; genetics ; metabolism

OBJECTIVETo establish a whole-body visualization model of breast cancer with high hepatic metastatic potential in nude mice and observe the development and metastasis of breast cancer by real-time imaging.

METHODSpEGFP-N1 plasmid was transfected into human breast cancer cell line MDA-MB-231 to obtain pEGFP-MDA-MB-231 cells that emitted fluorescence. pEGFP-MDA-MB-231 cells were inoculated orthotopically in BALB/C nude mice and cultured in vivo through serial passage, thereby establishing the mouse model bearing tumors with high hepatic metastasis potential. The fluorescence emitted from the tumors was quantitatively detected and imaged with a fluorescence stereo microscope for real-time visualization of the tumor growth and metastasis.

RESULTSThe transfected breast cancer cells stably and efficiently expressed EGFP. After inoculation of the transfected cells in nude mice, 20% of the first-generation cells showed hepatic metastasis, and the rate increased to 80% among the second-generation and up to 100% among the third-generation cells. The reliability of this visualization model was validated with conventional pathological methods.

CONCLUSIONThe whole-body visualization model bearing breast cancer with high hepatic metastasis potential provides a reliable means for studying the mechanisms of hepatic tumor metastasis, and can be instrumental in the exploration of novel means for breast cancer treatment.

Animals ; Breast Neoplasms ; genetics ; metabolism ; pathology ; Cell Line, Tumor ; Disease Models, Animal ; Female ; Green Fluorescent Proteins ; genetics ; metabolism ; Humans ; Liver Neoplasms ; genetics ; metabolism ; secondary ; Mammary Neoplasms, Experimental ; genetics ; metabolism ; pathology ; Mice ; Mice, Inbred BALB C ; Mice, Nude ; Microscopy, Fluorescence ; Neoplasm Transplantation ; Transplantation, Heterologous

OBJECTIVETo establish a syngeneic mouse model of liver tumor stably expressing hepatitis B virus (HBV) antigens.

METHODSMelanoma cell line B16 cells were transfected with pLXSN-2HBV. Cells (named B16/HBV) stably and persistently expressing HBV surface (HBsAg) and core (HBcAg) antigens were identified. The cells were injected into the hepatic subcapsular space of fifteen C57BL/6J mice. The mice were divided into 3 groups, receiving 100, 1000 or 5000 cells in a total volume of 5 µl per mouse, respectively, five mice in each group. Two weeks after the tumor cell inoculation, serum samples from the mice were collected weekly and the serum concentration of HBsAg and anti-HBs was quantified by ELISA. The tumor growth in the mouse liver was monitored by a high-resolution ultrasound system. Expression of HBsAg and HBcAg in the tumor tissues was determined by immunohistochemistry.

RESULTSLiver tumors were formed in all the mice receiving 1000 and 5000 B16/HBV cells per mouse, and in 80% of the mice receiving 100 B16/HBV cells. HBsAg and anti-HBs were detectable in their sera from 2 weeks after tumor cell inoculation. The mice receiving 100 cells per mouse began to die 4 weeks, those receiving 1000 cells per mouse began to die 3 - 4 weeks and those receiving 5000 cells began to die 2 - 3 weeks after the cell inoculation. All the tumor cells expressed HBsAg and HBcAg.

CONCLUSIONSThe B16/HBV cells stably and persistently express HBV antigens both in vitro and in vivo. A mouse model of transplanted liver tumor stably expressing HBV antigens has been successfully established by inoculation of those cells into the hepatic subcapsular space.

Animals ; Cell Line, Tumor ; Disease Models, Animal ; Female ; Hepatitis B Core Antigens ; metabolism ; Hepatitis B Surface Antigens ; metabolism ; Hepatitis B e Antigens ; metabolism ; Hepatitis B virus ; genetics ; metabolism ; Liver Neoplasms, Experimental ; immunology ; virology ; Melanoma, Experimental ; metabolism ; pathology ; Mice ; Mice, Inbred C57BL ; Neoplasm Transplantation ; Plasmids ; Recombinant Proteins ; genetics ; metabolism ; Transfection

BACKGROUNDBreast cancer has become one of the most common malignant tumors among females over the past several years. Breast carcinogenesis is a continuous process, which is featured by the normal epithelium progressing to premalignant lesions and then to invasive breast cancer (IBC). Targeting premalignant lesions is an effective strategy to prevent breast cancer. The establishment of animal models is critical to study the mechanisms of breast carcinogenesis, which will facilitate research on breast cancer prevention and drug behaviors. In this study, we established a feasible chemically-induced rat model of premalignant breast cancer.

METHODSFollowing the administration of the drugs (carcinogen, estrogen, and progestogen) to Sprague-Dawley (SD) rats, tumors or suspicious tumors were identified by palpation or ultrasound imaging, and were surgically excised for pathological evaluation. A series of four consecutive steps were carried out in order to determine the carcinogen: 7,12-dimethylbenzaanthracene (DMBA) or 1-methyl-1-nitrosourea, the route of carcinogen administration, the administration period of estrogen and progestogen, and the DMBA dosage.

RESULTSStable premalignant lesions can be induced in SD rats on administration of DMBA (15 mg/kg, administered three times) followed by administration of female hormones 5-day cycle.

RESULTSwere confirmed by ultrasound and palpation.

CONCLUSIONUnder the premise of drug dose and cycle, DMBA combined with estrogen and progestogen can be used as a SD rat model for breast premalignant lesions.

9,10-Dimethyl-1,2-benzanthracene ; Animals ; Breast Diseases ; chemically induced ; Disease Models, Animal ; Female ; Mammary Neoplasms, Experimental ; chemically induced ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo establish New Zealand rabbit hepatoma models with VX2 cell line, and modify the hepatic artery catheterization technique.

METHODSForty New Zealand rabbit models bearing hepatoma were established by implanting VX2 cells into the left and right liver lobes. Two weeks after the tumor cell implantation, 26 rabbits in the experimental group underwent modified hepatic artery catheterization procedures using microsurgical technique, and 10 rabbits in the control group were catheterized with 3F micro-catheter using Seldinger technique. The VX2 hepatomas were observed before and after the catheterization with multi-slice spiral CT scan and digital subtractive angiography (DSA).

RESULTSTumor growth after the tumor cell implantation was confirmed in 36 rabbits by CT scans and open operations. The success rate of catheterization was 88% (23/26) in the experimental group, and 40% (4/10) in the control group. VX2 hepatomas appeared as hypointense or isointense nodules on multi-slice spiral CT, and hepatic artery angiography showed that VX2 hepatomas had homogeneous or nodular tumor staining.

CONCLUSIONThe modified hepatic artery catheterization using microsurgical technique has higher success rate than catheterization with 3F micro-catheter by Seldinger technique, and significantly decreases X-ray exposure for the staff undertaking the operations.

Animals ; Carcinoma, Hepatocellular ; pathology ; Catheterization ; methods ; Cell Line, Tumor ; Disease Models, Animal ; Female ; Hepatic Artery ; Liver Neoplasms, Experimental ; pathology ; Male ; Rabbits ; Radiography, Interventional ; Tomography, Spiral Computed

OBJECTIVETo improve the method for preparing rabbit VX2 liver tumor model and observe the magnetic resonance imaging (MRI) features of the implanted tumors.

METHODSSixteen adult New Zealand white rabbits were assigned randomly into 4 equal groups, and VX2 tumor tissues were implanted into the right and left liver lobes with spiral CT guidance. Plain and contrast-enhanced MR scan and pathological analysis were performed in different stages (14, 18, 22 and 26 days) after tumor implantation.

RESULTSTumor implantation was successful in all the rabbits, and 18 to 22 days after tumor implantation, the diameters of the tumor ranged from 1 to 2 cm, which allowed observation and study. In plain MR scans, lower or equivalent tumor signal in comparison with hepatic parenchyma was observed, and contrast-enhanced scans produced obvious enhancement of the tumor edges. At 22 days after tumor implantation, obvious necrosis was observed in the center of the tumor.

CONCLUSIONThis method of preparing rabbit VX2 liver tumor model with spiral CT guidance is simple and convenient, and the tumors can be observed effectively with dynamic plain and contrast-enhanced MR scans.

Animals ; Disease Models, Animal ; Female ; Liver Neoplasms, Experimental ; diagnostic imaging ; pathology ; Magnetic Resonance Imaging ; methods ; Male ; Neoplasm Transplantation ; Rabbits ; Random Allocation ; Tomography, X-Ray Computed

Angiography, Digital Subtraction ; Animals ; Disease Models, Animal ; Female ; Liver Neoplasms, Experimental ; diagnostic imaging ; pathology ; Male ; Neoplasm Transplantation ; Rabbits ; Tumor Cells, Cultured

OBJECTIVETo establish a modified rat model of liver cancer with concurrent cirrhosis for the study of carcinogenesis characteristics and drug intervention of liver cancer.

METHODSFifty male Wistar rats weighing 100-120 g were randomly divided into normal control group (20 rats) and model group (30 rats). In the model group, the rats were subjected to intraperitoneal injection of 50 mg/kg DEN N-diethylnitrosamine (DEN) twice a week for 4 consecutive weeks, followed then by weekly injections for another 10 weeks. The control rats received injections of 0.1 ml saline in the same manner. At 2, 4, 8, 12, 14, and 18 weeks, 3 rats from each group were sacrificed for assessing tumor formation and liver cirrhosis.

RESULTSLiver cancer with concurrent cirrhosis was induced successfully after 14 weeks of DEN injections. At the 14th week, 3 out of the 5 rats were found to have cirrhosis and LC, and at the 18th week, all the 3 rats examined had cirrhosis and liver cancer. The total carcinogenesis rate in the rats was 75% at 18 weeks with an overall mortality of 33%.

CONCLUSIONThis approach to establishing rat models of liver cancer with concurrent cirrhosis requires simple operation, shortens the time of carcinogenesis, and ensures a high success rate of carcinogenesis and a low mortality rate. The carcinogenesis characteristics in this model are similar to those in human.

Animals ; Liver Cirrhosis, Experimental ; complications ; pathology ; Liver Neoplasms, Experimental ; etiology ; pathology ; Male ; Rats ; Rats, Wistar