thioacetamide and Cholangiocarcinoma

Intrahepatic cholangiocarcinoma (ICC) has a poor prognosis. The bifunctional protein peroxiredoxin 6 (PRDX6), which has both calcium-independent phospholipase A2 (iPLA2) and glutathione peroxidase (GPx) activity, participates in the development of multiple tumors. However, the function and clinical significance of PRDX6 in ICC remain unclear. In this study, we characterized PRDX6 in both human ICC and thioacetamide (TAA)-induced rat ICC. We found PRDX6 was significantly increased in ICC tissues, compared with the peritumoral tissues, and PRDX6 expression level was positively correlated with the malignant phenotype in ICC patients. Furthermore, PRDX6 genetic knockout significantly inhibited the tumor progression in rats. By using RNA sequencing analysis, we found 127 upregulated genes and 321 downregulated genes after PRDX6 knockout. In addition, we noticed a significant repression in the Wnt7a/b cascade, which has been shown to play an important role in the occurrence of ICC. We confirmed that gene expressions in the Wnt7a/b cascade were inhibited in ICC tissues after PRDX6 knockout by using qRT-PCR and immunohistochemistry analysis. Collectively, our findings suggest that PRDX6 may promote ICC by regulating the Wnt7a/b pathway, which could be a novel therapeutic target for ICC.

Topics: Animals; Bile Duct Neoplasms; Bile Ducts, Intrahepatic; Cholangiocarcinoma; Glutathione Peroxidase; Humans; Peroxiredoxin VI; Rats; Thioacetamide

Cholangiocarcinoma (CCA) is the second most common primary liver malignancy and carries a dismal prognosis due to difficulties in achieving an optimal resection, and poor response to current standard-of-care systemic therapies. We previously devised a CTLA4-PD-L1 DNA cancer vaccine (DNA vaccine) and demonstrated its therapeutic effects on reducing tumor growth in a thioacetamide (TAA)-induced rat intrahepatic CCA (iCCA) model. Here, we developed a CTLA4-PD-L1 chimeric protein vaccine (Protein vaccine), and examined its effects in the rat iCCA model. In a therapeutic setting, iCCA-bearing rats received either DNA plus Protein vaccines or Protein vaccine alone, resulting in increased PD-L1 and CTLA-4 antibody titers, and reduced iCCA tumor burden as verified by animal positron emission tomography (PET) scans. Treating iCCA-bearing rats with Protein vaccine alone led to the increase of CTAL4 antibody titers that correlated with the decrease of tumor SUV ratio, indicating regressed tumor burden, along with increased <i>CD8</i> and granzyme A (<i>GZMA</i>) expression, and decreased PD-L1 expression on tumor cells. In a preventive setting, DNA or Protein vaccines were injected in rats before the induction of iCCA by TAA. Protein vaccines induced a more sustained PD-L1 and CTLA-4 antibody titers compared with DNA vaccines, and was more potent in preventing iCCA tumorigenesis. Correspondingly, Protein vaccines, but not DNA vaccines, downregulated PD-L1 gene expression and hindered the carcinogenesis of iCCA. Taken together, the CTLA4-PD-L1 chimeric protein vaccine may function both as a therapeutic cancer vaccine and as a preventive cancer vaccine in the TAA-induced iCCA rat model.

Topics: Animals; B7-H1 Antigen; Bile Duct Neoplasms; Bile Ducts, Intrahepatic; Cancer Vaccines; Carcinogenesis; Cell Transformation, Neoplastic; Cholangiocarcinoma; CTLA-4 Antigen; Immune Checkpoint Proteins; Rats; Recombinant Fusion Proteins; Thioacetamide

Intrahepatic cholangiocarcinoma (iCCA) is closely correlated with hepatic progenitor cell (HPC) expansion and liver fibrosis. Brahma-related gene 1 (Brg1), an enzymatic subunit of the switch/sucrose nonfermentable complex that is critical in stem cell maintenance and tumor promotion, is prominently up-regulated in both HPCs and iCCA; however, its role in this correlation remains undefined.. A retrospective cohort study indicated that high Brg1 expression suggests poor prognosis in patients with iCCA. In chronically injured livers induced by a 0.1% 3,5-diethoxycarbonyl-1,4-dihydrocollidine diet or bile duct ligation surgery, HPCs were dramatically activated, as indicated by their enhanced expression of Brg1 and a subset of stem cell markers; however, Brg1 ablation in HPCs strongly suppressed HPC expansion and liver fibrosis. Furthermore, in a chemically induced iCCA model, inhibition of Brg1 by a specific inhibitor or inducible gene ablation markedly improved histology and suppressed iCCA growth. Mechanistically, in addition to transcriptionally promoting both Wnt receptor genes and target genes, Brg1 was found to bind to the β-catenin/transcription factor 4 transcription complex, suggesting a possible approach for regulation of Wnt/β-catenin signaling.. We have demonstrated the function of Brg1 in promoting HPC expansion, liver cirrhosis, and, ultimately, iCCA development in chronically injured livers, which is largely dependent on Wnt/β-catenin signaling. Our data suggest that therapies targeting Brg1-expressing HPCs are promising for the treatment of liver cirrhosis and iCCA.

Topics: Adult; Aged; Animals; Azabicyclo Compounds; Bile Duct Neoplasms; Bile Ducts, Intrahepatic; Cholangiocarcinoma; Disease-Free Survival; DNA Helicases; Female; Gene Expression Regulation, Neoplastic; Humans; Liver; Liver Cirrhosis; Male; Mice; Mice, Transgenic; Middle Aged; Neoplasm Recurrence, Local; Neoplasms, Experimental; Nuclear Proteins; Prognosis; Pyridines; Retrospective Studies; Stem Cells; Thioacetamide; Transcription Factors; Up-Regulation; Wnt Signaling Pathway

Cholangiocarcinoma (CCA) is a devastating disease with very poor prognosis due to late diagnosis and resistance to traditional chemotherapies and radiotherapies. Herein, thioacetamide (TAA)-induced rat CCA model and CGCCA cell line were used; we aim to study the cytogenetic features during tumoral development of CCA and uncover the mystery regarding carcinogenesis of CCA. The Array comparative genomic hybridization analysis, in silico method, gene knockdown, Western blot, cell count proliferation assay, clonogenecity assay, and IHC staining were applied in this study. Array comparative genomic hybridization analysis was performed on all different TAA-induced phases of rat tissues to reveal the certain pattern, +2q45, +Xq22, -12p12, have been identified for the tumor early stage, where involve the gene TNNI3K. In addition, 16 genes and 3 loci were associated with rapid tumor progression; JAK-STAT signaling pathway was highly correlated to late stage of CCA. In silico database was used to observe TNNI3K was highly express at tumor part compared with normal adjacent tissue in CCA patients from TCGA dataset. Furthermore, the growth of TNNI3K-knockdown SNU308 and HuCCT1 cells decreased when compared with cells transfected with an empty vector cell demonstrated by proliferation and colonogenecity assay. Besides, over expression of TNNI3K was especially confirmed on human CCA tumors and compared with the intrahepatic duct stone bile duct tissues and normal bile duct tissues (P < 0.001). Our findings might uncover the mystery regarding carcinogenesis of CCA, and provide the potential genetic mechanism to the clinicians some ideas for the patients' treatment.

Topics: Adult; Aged; Aged, 80 and over; Animals; Bile Duct Neoplasms; Cell Line, Tumor; Cell Proliferation; Cell Survival; Cholangiocarcinoma; Comparative Genomic Hybridization; Female; Gene Expression Regulation, Neoplastic; Gene Knockdown Techniques; Humans; Male; MAP Kinase Kinase Kinases; Middle Aged; Prognosis; Protein Serine-Threonine Kinases; Rats; Signal Transduction; Thioacetamide; Up-Regulation; Young Adult

Intrahepatic cholangiocarcinoma (ICC) is a malignant epithelial neoplasm composed of cells resembling cholangiocytes that line the intrahepatic bile ducts in portal areas of the hepatic lobule. Although ICC has been defined as a tumor arising from cholangiocyte transformation, recent evidence from genetic lineage-tracing experiments has indicated that hepatocytes can be a cellular origin of ICC by directly changing their fate to that of biliary lineage cells. Notch signaling has been identified as an essential factor for hepatocyte conversion into biliary lineage cells at the onset of ICC. However, the mechanisms underlying Notch signal activation in hepatocytes remain unclear. Here, using a mouse model of ICC, we found that hepatic macrophages called Kupffer cells transiently congregate around the central veins in the liver and express the Notch ligand Jagged-1 coincident with Notch activation in pericentral hepatocytes. Depletion of Kupffer cells prevents the Notch-mediated cell-fate conversion of hepatocytes to biliary lineage cells, inducing hepatocyte apoptosis and increasing mortality in mice. These findings will be useful for uncovering the pathogenic mechanism of ICC and developing prevenient and therapeutic strategies for this refractory disease.

Topics: Animals; Bile Duct Neoplasms; Bile Ducts, Intrahepatic; Carcinogens; Cell Communication; Cell Dedifferentiation; Cholangiocarcinoma; Clodronic Acid; Disease Models, Animal; Gene Expression Regulation; Hepatocytes; Humans; Jagged-1 Protein; Kupffer Cells; Mice; Mice, Inbred C57BL; Pyridines; Receptor, Notch1; Signal Transduction; Survival Analysis; Thioacetamide

Bile acid accumulation in liver with cholangiolar neoplastic lesions may occur before cholestasis is clinically detected. Whether this favors intrahepatic cholangiocarcinoma development has been investigated in this study. The E. coli RecA gene promoter was cloned upstream from Luc2 to detect in vitro direct genotoxic ability by activation of SOS genes. This assay demonstrated that bile acids were not able to induce DNA damage. The genotoxic effect of the DNA-damaging agent cisplatin was neither enhanced nor hindered by the hepatotoxic and hepatoprotective glycochenodeoxycholic and glycoursodeoxycholic acids, respectively. In contrast, thioacetamide metabolites, but not thioacetamide itself, induced DNA damage. Thus, thioacetamide was used to induce liver cancer in rats, which resulted in visible tumors after 30 weeks. The effect of bile acid accumulation on initial carcinogenesis phase (8 weeks) was investigated in bile duct ligated (BDL) animals. Serum bile acid measurement and determination of liver-specific healthy and tumor markers revealed that early thioacetamide treatment induced hypercholanemia together with upregulation of the tumor marker Neu in bile ducts, which were enhanced by BDL. Bile acid accumulation was associated with increased expression of interleukin (IL)-6 and downregulation of farnesoid X receptor (FXR). Bile duct proliferation and apoptosis activation, with inverse pattern (BDL > thioacetamide + BDL >> thioacetamide vs. thioacetamide > thioacetamide + BDL > BDL), were observed. In conclusion, intrahepatic accumulation of bile acids does not induce carcinogenesis directly but facilitates a cocarcinogenic effect due to stimulation of bile duct proliferation, enhanced inflammation, and reduction in FXR-dependent chemoprotection.. This study reveals that bile acids foster cocarcinogenic events that impact cholangiocarcinoma.

Topics: Animals; Apoptosis; Bile Acids and Salts; Bile Duct Neoplasms; Bile Ducts, Intrahepatic; Biomarkers, Tumor; Cell Proliferation; Cells, Cultured; Cholangiocarcinoma; Cholestasis; Cholic Acids; Cisplatin; Cocarcinogenesis; Cross-Linking Reagents; DNA Damage; Glycochenodeoxycholic Acid; Hepatocytes; Inflammation; Interleukin-6; Liver; Liver Neoplasms; Male; Promoter Regions, Genetic; Rats; Rats, Wistar; Rec A Recombinases; Receptor, ErbB-2; Receptors, Cytoplasmic and Nuclear; SOS Response, Genetics; Thioacetamide

Cholangiocarcinoma (CCA) is a malignant neoplasm affecting thousands of individuals worldwide. CCA develops through a multistep process. In the current study, an oral thioacetamide (TAA)‑induced model of rat CCA was established which generates the histological progression of human CCA, particularly the mass‑forming type. Seven male Sprague‑Dawley rats were treated with TAA for 24 weeks to induce CCA. Following the generation of the rat CCA model, whole rat genomic oligo microarray was performed to examine gene expression profiles in CCA and non‑cancerous liver samples. In brief, 10,427 genes were found to be differentially expressed (8,318 upregulated and 3,489 downregulated) in CCA compared with non‑tumor liver tissue. The top 50 genes (upregulated or downregulated) were selected and their functional involvement in various pathways associated with cancer progression was analyzed, including cell proliferation, apoptosis, metabolism and the cell cycle. In addition, increased expression of CLCA3, COL1A2, DCN, GLIPr2 and NID1, and decreased expression of CYP2C7 and SLC10A1 were validated by quantitative real‑time PCR. Immunohistochemical analysis was performed to determine the protein expression levels of GLIPr2 and SLC10A1. The gene expression profiling performed in this study provides a unique opportunity for understanding the carcinogenesis of TAA‑induced CAA. In addition, expression profiling of a number of specific genes is likely to provide important novel biomarkers for the diagnosis of CCA and the development of novel therapeutic strategies for CCA.

Topics: Animals; Bile Duct Neoplasms; Bile Ducts, Intrahepatic; Cholangiocarcinoma; Disease Models, Animal; Gene Expression Profiling; Gene Expression Regulation, Neoplastic; Humans; Liver; Male; Membrane Proteins; Organic Anion Transporters, Sodium-Dependent; Rats; Reproducibility of Results; Symporters; Thioacetamide

It has been recently shown that the biological effects of erythropoietin (EPO) are not limited to the hematopoietic compartment but, as pleiotropic glycoprotein, this hormone can exert pro-angiogenic and tissue-protective functions also in a wide range of non-hematopoietic organs. The role of EPO and the effective functionality of its receptor in solid tumors are still a controversial point of debate. In the present work we analyzed the gene expression of EPO and its cognate receptor (EpoR) in a rat model of thioacetamide-induced damage and tumor. An analysis of the EPO/EpoR axis was also performed on human cholangiocarcinoma (CC) cell lines. A progressive increase of EPO and EpoR mRNA can already be observed during the fibrotic-cirrhotic development with a peak of expression rising at tumor formation (24.7 ± 9.9-fold increase and 15.5 ± 1.1-fold increase, respectively, for the two genes). Co-localization studies by immunofluorescence revealed hepatocytes in the regenerative cirrhotic nodules (Hep Par-1(+)) and in the dysplastic bile duct cells (CK19(+)) as the major EPO producers in this specific condition. The same cell populations, together with endothelial cells, exhibited an increased expression of EpoR, although all the non-parenchymal cell populations in the liver exhibited modest basal mRNA levels. Challenging human CC cells, Mz-Cha-2, with a combination of EPO and SCF resulted in a synergistic effect on the gene expression of EPO, CyclinD1 and PCNA. This study suggests that the autocrine and paracrine release of endogenous EPO in the microenvironment may contribute to the development and maintenance of the CC possibly in cooperation with other signaling pathways.

Topics: Animals; Bile Duct Neoplasms; Cholangiocarcinoma; Disease Models, Animal; Erythropoietin; Humans; Liver; Male; Rats; Rats, Sprague-Dawley; Receptors, Erythropoietin; RNA, Messenger; Thioacetamide; Tumor Cells, Cultured

Considerable evidence has demonstrated that transforming growth factor β (TGF-β) plays a key role in hepatic fibrosis, the final common pathway for a variety of chronic liver diseases leading to liver insufficiency. Although a few studies have reported that blocking TGF-β with soluble receptors or siRNA can prevent the progression of hepatic fibrosis, as yet no evidence has been provided that TGF-β antagonism can improve pre-existing hepatic fibrosis. The aim of this study was to examine the effects of a murine neutralizing TGF-β monoclonal antibody (1D11), in a rat model of thioacetamide (TAA)-induced hepatic fibrosis. TAA administration for 8 weeks induced extensive hepatic fibrosis, whereupon 1D11 dosing was initiated and maintained for 8 additional weeks. Comparing the extent of fibrosis at two time points, pre- and post-1D11 dosing, we observed a profound regression of tissue injury and fibrosis upon treatment, as reflected by a reduction of collagen deposition to a level significantly less than that observed before 1D11 dosing. Hepatic TGF-β1 mRNA, tissue hydroxyproline, and plasminogen activator inhibitor 1 (PAI-1) levels were significantly elevated at the end of the 8 week TAA treatment. Vehicle and antibody control groups demonstrated progressive injury through 16 weeks, whereas those animals treated for 8 weeks with 1D11 showed striking improvement in histologic and molecular endpoints. During the course of tissue injury, TAA also induced cholangiocarcinomas. At the end of study, the number and area of cholangiocarcinomas were significantly diminished in rats receiving 1D11 as compared to control groups, presumably by the marked reduction of supporting fibrosis/stroma. The present study demonstrates that 1D11 can reverse pre-existing hepatic fibrosis induced by extended dosing of TAA. The regression of fibrosis was accompanied by a marked reduction in concomitantly developed cholangiocarcinomas. These data provide evidence that therapeutic dosing of a TGF-β antagonist can diminish and potentially reverse hepatic fibrosis and also reduce the number and size of attendant cholangiocarcinomas.

Topics: Animals; Antibodies, Monoclonal, Murine-Derived; Cholangiocarcinoma; Humans; Liver; Liver Cirrhosis; Male; Mice; Molecular Targeted Therapy; Plasminogen Activator Inhibitor 1; Rats; Signal Transduction; Thioacetamide; Transforming Growth Factor beta

Stem cell factor (SCF) and its receptor, c-Kit, constitute an important signal transduction system with proliferative and anti-apoptotic functions. Besides regulating hemopoietic stem cell proliferation and liver regeneration, it has been implicated in the regulation of human malignancies. However, the cellular expression of the SCF-c-Kit gene system in the liver during cholangiocarcinogenesis has not been studied to date. The protein- and mRNA-expression levels of SCF and c-Kit genes were examined in normal rat liver, in isolated normal rat liver cells and in a thioacetamide-induced rat model of intrahepatic cholangiocarcinoma (CC). Immunohistochemical analysis of the normal liver showed that SCF is expressed in the wall of the hepatic artery and in some cells, which were located along the sinusoids, although it was absent from hepatocytes and biliary epithelial cells. The mRNA analysis of isolated normal liver cell populations revealed a co-expression of SCF- and c-Kit-mRNA in sinusoidal endothelial cells and in Kupffer cells, whereas passaged and cultured liver myofibroblasts (MFs) expressed only SCF. Low levels of the SCF- and c-Kit-mRNA expression could be detected in isolated hepatocytes of the normal liver. Immunohistochemical analysis of the CC tissue showed SCF positivity in proliferating biliary cells (CK-19(+)), in macrophages (ED-1(+)) and in MFs (alpha-smooth-muscle-actin, alpha-SMA(+)) of the tumoral microenvironment. c-Kit-positivity could be detected on hepatocytes of the regenerating nodules and on the proliferating bile ducts of CC. Compared with the normal liver tissue, SCF-mRNA from the CC tissue was upregulated up to 20-fold, whereas c-Kit-mRNA was upregulated up to fivefold. These data indicate that several cell populations may become able to express SCF and/or c-Kit during cholangiocarcinogenesis. Therefore, the SCF-c-Kit system may contribute to tumor development, for instance, by inducing proliferation of hepatocytes and of biliary cells and by acting as a surviving factor for CC cells.

Topics: Animals; Bile Ducts, Intrahepatic; Blotting, Western; Cholangiocarcinoma; Hepatocytes; Immunohistochemistry; Liver; Liver Neoplasms, Experimental; Male; Proto-Oncogene Proteins c-kit; Rats; Rats, Sprague-Dawley; RNA, Messenger; Stem Cell Factor; Thioacetamide

Cholangiocarcinoma is a strongly aggressive malignancy with a very poor prognosis. Effective therapeutic strategies are lacking because molecular mechanisms regulating cholangiocarcinoma cell growth are unknown. Furthermore, experimental in vivo animal models useful to study the pathophysiologic mechanisms of malignant cholangiocytes are lacking. Leptin, the hormone regulating caloric homeostasis, which is increased in obese patients, stimulates the growth of several cancers, such as hepatocellular carcinoma. The aim of this study was to define if leptin stimulates cholangiocarcinoma growth. We determined the expression of leptin receptors in normal and malignant human cholangiocytes. Effects on intrahepatic cholangiocarcinoma (HuH-28) cell proliferation, migration, and apoptosis of the in vitro exposure to leptin, together with the intracellular pathways, were then studied. Moreover, cholangiocarcinoma was experimentally induced in obese fa/fa Zucker rats, a genetically established animal species with faulty leptin receptors, and in their littermates by chronic feeding with thioacetamide, a potent carcinogen. After 24 weeks, the effect of leptin on cholangiocarcinoma development and growth was assessed. Normal and malignant human cholangiocytes express leptin receptors. Leptin increased the proliferation and the metastatic potential of cholangiocarcinoma cells in vitro through a signal transducers and activators of transcription 3-dependent activation of extracellular signal-regulated kinase 1/2. Leptin increased the growth and migration, and was antiapoptotic for cholangiocarcinoma cells. Moreover, the loss of leptin function reduced the development and the growth of cholangiocarcinoma. The experimental carcinogenesis model induced by thioacetamide administration is a valid and reproducible method to study cholangiocarcinoma pathobiology. Modulation of the leptin-mediated signal could be considered a valid tool for the prevention and treatment of cholangiocarcinoma.

Topics: Animals; Bile Duct Neoplasms; Bile Ducts; Bile Ducts, Intrahepatic; Cell Proliferation; Cholangiocarcinoma; Fluorescent Antibody Technique; Humans; Janus Kinases; Leptin; Mitogen-Activated Protein Kinase 1; Mitogen-Activated Protein Kinase 3; Mitogen-Activated Protein Kinase Kinases; Phosphorylation; Proto-Oncogene Proteins c-akt; Rats; Rats, Zucker; Receptors, Leptin; Reverse Transcriptase Polymerase Chain Reaction; STAT3 Transcription Factor; Thioacetamide

Cholangiocarcinoma (CCA) is a lethal disease, afflicting many thousands the world over. Human CCA develops through a multi-step progression model, preceded by the onset of dysplasia in the cholangiolar ductal epithelium. An animal model of multi-step carcinogenesis in the biliary tree will enable the study of genetic changes in human CCA, and provide an avenue for chemoprevention strategies. We describe an oral thioacetamide (TAA)-induced model of rat CCA that recapitulates the histologic progression of human CCA. Male Sprague-Dawley (SD) rats (n = 170), weighing 350 +/- 20 g, were used in this study. Drinking water with TAA 300 mg/l was administered orally, and the liver was harvested and examined histologically at weekly intervals, beginning at 5 weeks after initiation of TAA. Harvested tissues were formalin-fixed and paraffin embedded for morphologic and immunohistochemical studies. Multifocal bile ductular proliferation with intestinal metaplasia (presence of goblet cells) and increasing histologic atypia (biliary dysplasia) was observed by the 9th week of TAA administration. Biliary cytokeratin (CK19)-expressing invasive intestinal-type CCA with stromal desmoplasia was evident at the 16th week, and by the 22nd week, the yield rate for CCAs had increased to 100%. Invasive CCAs preceded the development of hepatic cirrhosis by at least 4 weeks; the earliest incidence of hepatic fibrosis was observed beginning at 20 weeks post-TAA administration. The progression from normal cholangioles to biliary dysplasia to invasive CCA was accompanied by up-regulation of the proto-oncogenes c-met and c-erbB-2, tyrosine kinase receptors over-expressed in human CCAs. The study was terminated at 6 months, at which time no systemic metastases or deaths were observed. Oral administration of TAA in drinking water to male SD rats provides a reproducible animal model for development of CCA with a high yield rate. In particular, the presence of biliary dysplasia beginning at the 9th week, which progresses to invasive CCA, mimics the multi-step model of human CCA. The TAA rat model may serve as a powerful pre-clinical platform for therapeutic and chemoprevention strategies for human CCA.

Topics: Animals; Carcinogens; Cholangiocarcinoma; Disease Models, Animal; Disease Progression; Humans; Intestinal Neoplasms; Male; Rats; Rats, Sprague-Dawley; Thioacetamide; Time Factors

We sought to determine the expression of molecular markers in an animal model of cholangiocarcinoma compared with those in human cholangiocarcinoma.. Cholangiocarcinoma is a rare disease characterized by early intrahepatic and extrahepatic spread, which seriously limits the efficacy of surgery. Establishing an experimental model to study the cholangiocarcinogenesis is desirable.. Sprague-Dawley rats weighing 300 +/- 50 g were used for the study group. The animals were given 0.3% thioacetamide in tap water continuously. Thirty mass-forming peripheral cholangiocarcinoma patients also were studied. Expression of epidermal growth factor receptor (EGFR), MUC1, MUC2, MUC5AC, MMP-2, MMP-9, and p53 in both human and experimental rat cholangiocarcinoma was examined using immunohistochemistry.. Using thioacetamide 0.3% as a hepatoxin to induce cholangiocarcinoma in rats, microfoci of cancerous cells were detected from 12 weeks, and all experimental rats displayed diffuse mass-forming cholangiocarcinoma after 24 weeks. EGFR was strongly expressed in 14 (47%) of 30 human cholangiocarcinoms and 24 (100%) of 24 rat cholangiocarcinomas, respectively. MUC1 was strongly expressed in all human and rat cholangiocarcinomas, whereas MUC2 and MUC5AC were focally and weakly expressed. MMP-2 and MMP-9 were strongly expressed in 22 (73%) of 30 human cholangiocarcinomas and 24 (100%) of 24 rat cholangiocarcinomas, respectively. p53 overexpression was detected in 9 (30%) of 30 human cholangiocarcinoma and none of the rat cholangiocarcinoma, respectively.. The expression of EGFR, apomucins, MMPs, and p53 in rat cholangiocarcinoma was strongly homologous to human cholangiocarcinoma. Thioacetamide-induced cholangiocarcinoma in rats provides an excellent model for investigating cholangiocarcinogenesis in vivo.

Topics: Animals; Bile Duct Neoplasms; Bile Ducts, Intrahepatic; Cholangiocarcinoma; Disease Models, Animal; ErbB Receptors; Humans; Immunohistochemistry; Matrix Metalloproteinases; Mucins; Rats; Rats, Sprague-Dawley; Thioacetamide; Tumor Suppressor Protein p53

Different doses of thioacetamide (0.05%, 0.1% and 0.15%) were used to induce liver cirrhosis in Wistar rats. Thioacetamide at 0.5% caused cirrhosis by the twelfth week of treatment. A severe bile duct proliferation and cholangiocarcinoma was seen at longer intervals. Animals treated with higher doses (0.1% and 0.15%) of thioacetamide developed more severe intense degenerative changes in the liver and died in the twelfth and eighth week respectively. The serum and tissue contents of Zn and Cu changed in a characteristic fashion that was consistent with the severity of the liver damage. Serum Zn and Cu concentrations were at their lowest in the animals that developed severe degenerative liver and died at higher dose (0.15%) of thioacetamide. This study indicates that treatment of rats with 0.05% thiocetamide is more effective and appropriate for the induction of liver cirrhosis. Continued administration of the drug at this dosage led to the development of further changes in the liver. This model may be suitable for studying these long term changes that occur in the liver and lead to cirrhosis. Events that precede the development of severe bile duct proliferation and cholangiocarcinoma may also be studied.

Topics: Animals; Bile Duct Neoplasms; Body Weight; Cholangiocarcinoma; Copper; Diet; Dose-Response Relationship, Drug; Histocytochemistry; Liver; Liver Cirrhosis, Experimental; Male; Rats; Rats, Wistar; Thioacetamide; Time Factors; Zinc