OBJECTIVETo understand the molecular mechanism and find out the responsible genes for liver cancer by exploring the regulation of gene expression during hepatocarcinogenesis in tree shrew induced by aflatoxin B1 (AFB1).

METHODSThe tissues from tree shrew of different stages during the pathogenesis and development of hepatocellular carcinoma (HCC), liver cancer tissue, para-cancerous tissues, pre-cancerous liver tissues, liver tissues of the same stage from normal controls and the liver tissues taken before AFB1-treatment were analyzed for gene expression by cDNA array.

RESULTSFour patterns of gene expression were observed during AFB1-induced hepatocarcinogenesis. They were: genes up-regulated in HCC tissue and para-cancerous tissue, especially in HCC tissues; genes with similar expressing level in both HCC tissue and para-cancerous tissue, but higher than that in pre-cancerous tissue; genes down-regulated in HCC tissue; genes up-regulated before HCC appeared but down-regulated after HCC appeared.

CONCLUSIONDynamic observation of gene expression will be beneficial to elucidate the mechanisms of AFB1- induced hepatocarcinogenesis and locate the responsible genes.

Aflatoxin B1 ; toxicity ; Animals ; Gene Expression Profiling ; Liver Neoplasms, Experimental ; chemically induced ; genetics ; Oligonucleotide Array Sequence Analysis ; methods ; Tupaiidae

We investigated the expression of the growth-related nuclear proto-oncogenes, c-fos and c-myc, in early preneoplastic regions and tumor nodules of 3'-MeDAB induced rat hepatocarcinoma. To amplify the levels of these transcripts, we gave cycloheximide (100 mg/kg B.W. i.p.) to each group of rats. The elevated levels of the 2.2 kb c-fos and 2.4 kb c-myc transcripts appeared as early as the 2nd week after feeding on the 3'-MeDAB diet and lasted through the 4th; 6th weeks and tumor. Southern blot analysis indicated that gross amplification or rearrangements were not observed in DNA of the preneoplastic livers and hepatoma nodules. We also measured the rate of the incorporation of [3H] thymidine into hepatic DNA in order to monitor the rate of cell proliferation occurring at the early preneoplastic periods. We have found that the rate of [3H] thymidine incorporation corresponds to the elevated levels of c-fos and c-myc transcripts in the precancerous stages. This finding suggests that the elevated expressions of c-fos and c-myc may result from the continuous cell proliferative stimuli generated in the carcinogen altered cells, which is essential to the initiation and promotion of chemical hepatocarcinogenesis.
Animal ; Blotting, Southern ; DNA/biosynthesis ; Female ; *Gene Expression ; *Genes, fos ; *Genes, myc ; Liver Neoplasms, Experimental/chemically induced/*genetics ; Methyldimethylaminoazobenzene/*toxicity ; Precancerous Conditions/chemically induced/*genetics ; Rats ; Rats, Sprague-Dawley ; Support, Non-U.S. Gov't

Animals ; Antineoplastic Agents ; therapeutic use ; Chromans ; therapeutic use ; Diethylnitrosamine ; Ligands ; Liver Neoplasms, Experimental ; chemically induced ; drug therapy ; Male ; PPAR gamma ; biosynthesis ; genetics ; Rats ; Rats, Wistar ; Thiazolidinediones ; therapeutic use

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 determine the dynamic expression of survivin gene in hepatocarcinogenesis of rats induced by aflatoxin B1 (AFB1).

METHODS78 Sprague-Dawley rats were used in this study. Hepatocellular carcinoma was induced in the rats by aflatoxin B1. Liver and HCC tissues were examined by immunohistochemistry and reverse transcriptase-polymerase chain reaction (RT-PCR).

RESULTSThe earliest hepatocellular carcinoma occurred at 46th week after AFB1 treatment. The HCC incidence was 54.9% (28/51) at 46th week and 64.9% (24/37) at 58th week. The positive rates of survivin protein expression in 24 HCC, para-cancerous liver tissues of experimental group were 41.7% and 54.2%, respectively, with no significant difference between them (P > 0.05). No survivin expression was detected in the experimental group before 46th week, neither in the rats without HCC occurrence nor the normal controls. The level of survivin mRNA expression in HCC at 58th week was significantly higher than that in pre-HCC, no-HCC and normal liver tissues in the control group (P < 0.01). The level of survivin mRNA expression in para-carcinoma tissues was also significantly higher than that in no-HCC and normal liver tissues of the control (P < 0.01). The level of survivin mRNA in pre-HCC at 12th, 20th, 36th, 46th weeks were significantly higher than those in normal liver tissues taken from control group during the same periods (P < 0.01).

CONCLUSIONThe over-expression of survivin gene is related to the occurrence of HCC and may play an important role in the carcinogenesis of HCC.

Aflatoxin B1 ; Animals ; Apoptosis Regulatory Proteins ; genetics ; metabolism ; Gene Expression Regulation, Neoplastic ; Liver ; metabolism ; Liver Neoplasms, Experimental ; chemically induced ; metabolism ; Male ; Microtubule-Associated Proteins ; genetics ; metabolism ; RNA, Messenger ; metabolism ; Random Allocation ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo investigate the effects of herbal compound 861 (Cpd861) on hepatocarcinogenesis induced by diethylntrosamine and 2-acetylaminofluorene (DEN-AAF) in female Sprague Dawley rats.

METHODSLiver preneoplastic foci were induced using the DEN-AAF method in female Sprague Dawley rats, which were then treated with Cpd861. For quantitative assessment of liver preneoplastic foci, the placental form of glutathione-S-transferase (GST-P) positive foci were measured using immunohistochemical staining and image analysis. GST-P protein expression was measured by Western blotting, mRNA expression was assessed by Northern blotting.

RESULTSTreatment using DEN-AAF caused a significant decrease in body weight and increase in liver weight compared to the control group. Oral Cpd861 administration essentially prevented DEN-AAF-induced body weight loss and liver weight increase. When 2-AAF was followed by treatment with Cpd861, there was a decrease in the number of large foci as compared to 2-AAF alone. However, there were still considerable numbers of small mixed clear/vacuolated cell foci, some of which were positive for GST-P. Significant increase in GST-P protein and mRNA expression were observed in the DEN-AAF group, while treatment with Cpd861 inhibited the increase. The effect of Cpd861 on hepatocarcinogenesis occurred in a concentration-dependent manner.

CONCLUSIONChinese herbal compound Cpd861 prevents hepatocarcinogenesis in DEN-AAF-induced liver preneoplastic lesions in rats.

2-Acetylaminofluorene ; Animals ; Blotting, Northern ; Blotting, Western ; Body Weight ; Diethylnitrosamine ; Drugs, Chinese Herbal ; therapeutic use ; Female ; Glutathione Transferase ; genetics ; Liver ; pathology ; Liver Neoplasms, Experimental ; chemically induced ; drug therapy ; pathology ; Organ Size ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo investigate the changes in transforming growth factor beta 1 (TGF-beta1)/Smads signaling pathway in rats with chemical hepatocarcinogenesis.

METHODSFresh diethylnitrosamine (DENA) solution was administered in SD rats to induce hepatocellular carcinoma (HCC). The protein expressions of TGF-beta1, phosphorylated Smad2, Smad4 and Smad7 were detected in these rats with immunohistochemistry, and the mRNA expression of Smad4 was evaluated with RT-PCR.

RESULTSCirrhotic nodules occurred in the rats 8 weeks after DENA treatment, and HCC nodules were found 16 weeks after the treatment. In the normal liver tissue, very low levels of TGF-beta1 and Smad4 expressions, low Smad7 expression and high phosphorylated Smad2 expression were detected. The development of liver cirrhosis was accompanied by increased expressions of TGF-beta1, Smad4 and Smad7 but at 8 weeks after DENA treatment, the expression of phosphorylated Smad2 was significantly decreased, followed then by gradual increment till nearly the normal level. Twenty-two weeks after DENA treatment, Smad4 expression in liver tissue decreased markedly as compared with the levels at 8 and 16 weeks. The expressions of Smad4 and phosphorylated Smad2 in the HCC tissue was significantly lower than those in normal liver tissue.

CONCLUSIONHepatocarcinogenesis involves very complex mechanisms, can can be related partially to the decreased Smad4 and phosphorylated Smad2 expression and TGFbeta1 and Smad7 overexpression in advanced stage of liver cirrhosis.

Animals ; Diethylnitrosamine ; Liver Neoplasms, Experimental ; chemically induced ; metabolism ; pathology ; Male ; Rats ; Rats, Sprague-Dawley ; Signal Transduction ; Smad2 Protein ; metabolism ; Smad4 Protein ; metabolism ; Smad7 Protein ; metabolism ; Transforming Growth Factor beta1 ; genetics ; metabolism

The effects of A-L tonic capsule on DNA content in rat experimental hepatocarcinogenesis induced by diethylnitrosamine (DENA) were observed. The experimental rats were divided into 4 groups. With exception of group D in which the rats were only administered with DENA, the rats in the groups A, B, C were previously, simultaneously and subsequently fed with A-L tonic capsule respectively while they were administered with DENA. The DNA content of all rat livers was measured using automatic image analysis technique 20 weeks after administration of DENA. The results showed that the highest and lowest DNA contents were respectively seen in the groups D and A. There was significant difference in DNA contents between the groups A or B or C and D, and also between the groups A and B or C (both P < 0.01). 4 components (4C) and > or = 5C cells were predominant in the group D, while 2C cells were the minority. The number of 2C cells in the groups A, B, C was significantly higher than that in the group D, and the number of > or = 5C cells in the groups A, B, C was markedly lower than that in the group D (P < 0.01). Also, there was very significant difference in the number of 2C and > or = 5C cells between group A and B or C (P < 0.01). It was concluded that A-L tonic capsule could effectively inhibit the increase of DNA content of hepatocytes and improve the distribution of DNA content in rat hepatocarcinogenesis, especially in group A.
Animals ; Astragalus membranaceus ; chemistry ; Capsules ; Carcinogenicity Tests ; DNA, Neoplasm ; analysis ; Diethylnitrosamine ; Drugs, Chinese Herbal ; pharmacology ; Hepatocytes ; chemistry ; Ligustrum ; chemistry ; Liver Neoplasms, Experimental ; chemically induced ; chemistry ; genetics ; Male ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo construct a dendritic cell vaccine transduced by murine alpha-fetoprotein (mAFP) gene, and evaluate its immunoprotective effect on C57BL/6J mice during the induction of hepatocellular carcinoma by diethylnitrosamines, carbon tetrachloride and ethanol.

METHODSDendritic cells (DCs) were induced and augmented by murine IL-4 and GM-CSF, and transfected by recombinant adenovirus engineered with mAFP gene. Major MHC class I and II, B7.1 (CD80), B7.2 (CD86), CD18a, and CD54 molecules on DC were analyzed by FACS. 80 C57BL/6J male mice were randomly divided into 4 groups (20 mice per group): Simple DC inoculated group, pAdBM5-mAFP-DC inoculated group, pAdBM5-mAFP plasmid inoculated group, and PBS control group. They were immunized once with 5 x 10(5) DCs (0.1 ml)/mouse administered s. c. in the left flank or 100 mg pAdBMS-mAFP plasmid/mouse administered i. m. in the left tibialis anterior muscle. Inoculation was conducted once a week for 4 weeks after 3 times consecutive immunization initially. At the same time of immunization, DEN/CCl4/ethanol were given to induce hepatocellular carcinoma. Tumor incidence was assessed after 20 weeks.

RESULTSA transgenic DC vaccine was successfully constructed and the mAFP transgenic DCs expressed high level molecules of major MHC class I and II , B7.1, B7.2, CD18a, and CD54. After the 20-week induction, the incidence of primary hepatocellular carcinoma (PLC) was 70.0% in simple DC inoculated group, 25.0% in pAdBMS-mAFP-DC inoculated group, 65.0% in pAdBM5-mAFP plasmid inoculated group, and 75.0% in PBS control group. There was a significant difference between group B and other groups (P < 0.05).

CONCLUSIONmAFP transgenic DC tumor vaccine inoculation may induce strong immunoprotection against liver carcinogenesis and tumor development and reduce PLC incidence induced by DEN/CCl4/ethanol.

Adenoviridae ; genetics ; Animals ; B7-1 Antigen ; metabolism ; Cancer Vaccines ; Carbon Tetrachloride ; Cells, Cultured ; Dendritic Cells ; cytology ; immunology ; metabolism ; Diethylnitrosamine ; Ethanol ; Genetic Vectors ; Histocompatibility Antigens Class I ; metabolism ; Histocompatibility Antigens Class II ; metabolism ; Intercellular Adhesion Molecule-1 ; metabolism ; Liver Neoplasms, Experimental ; chemically induced ; immunology ; prevention & control ; Male ; Mice ; Mice, Inbred C57BL ; Random Allocation ; Recombinant Proteins ; genetics ; metabolism ; Transfection ; alpha-Fetoproteins ; genetics ; metabolism