Expression patterns of cytokine, growth factor and cell cycle-related genes after partial hepatectomy in rats with thioacetamide-induced cirrhosis.

AIM: To examine the differences in the responses of normal and cirrhotic livers to partial hepatectomy in relation to the factors influencing liver regeneration. METHODS: Cirrhosis was induced in rats by administration of thioacetamide. Untreated rats were used as controls. The control rats as well as the cirrhotic rats were subjected to 70% partial hepatectomy. At different time points after hepatectomy, the livers were collected and the levels of cytokines, growth factors and cell cycle proteins were analyzed. RESULTS: After hepatectomy, the cirrhotic remnant expressed significantly lower levels of cyclin D1, its kinase partner, cdk4, and cyclin E as compared to the controls up to 72 h post hepatectomy. Significantly lower levels of cyclin A and cdk2 were also observed while the cdk inhibitor, p27 was significantly higher. In addition, the cirrhotic group had lower IL-6 levels than the control group at all time points up to 72 h following resection. CONCLUSION: The data from our study shows that impaired liver regeneration in cirrhotic remnants is associated with low expression of cyclins and cdks. This might be the consequence of the low IL-6 levels in cirrhotic liver remnant which would in turn influence the actions of transcription factors that regulate genes involved in cell proliferation and metabolic homeostasis during the regeneration process.

Cholecystectomy or gallbladder in situ after endoscopic sphincterotomy and bile duct stone removal in Chinese patients.

BACKGROUND & AIMS: In patients with stones in their bile ducts and gallbladders, cholecystectomy is generally recommended after endoscopic sphincterotomy and clearance of bile duct stones. However, only approximately 10% of patients with gallbladders left in situ will return with further biliary complications. Expectant management is alternately advocated. In this study, we compared the treatment strategies of laparoscopic cholecystectomy and gallbladders left in situ. METHODS: We randomized patients (>60 years of age) after endoscopic sphincterotomy and clearance of their bile duct stones to receive early laparoscopic cholecystectomy or expectant management. The primary outcome was further biliary complications. Other outcome measures included adverse events after cholecystectomy and late deaths from all causes. RESULTS: One hundred seventy-eight patients entered into the trial (89 in each group); 82 of 89 patients who were randomized to receive laparoscopic cholecystectomy underwent the procedure. Conversion to open surgery was needed in 16 of 82 patients (20%). Postoperative complications occurred in 8 patients (9%). Analysis was by intention to treat. With a median follow-up of approximately 5 years, 6 patients (7%) in the cholecystectomy group returned with further biliary events (cholangitis, n = 5; biliary pain, n = 1). Among those with gallbladders in situ, 21 (24%) returned with further biliary events (cholangitis, n = 13; acute cholecystitis, n = 5; biliary pain, n = 2; and jaundice, n = 1; log rank, P = .001). Late deaths were similar between groups (cholecystectomy, n = 19; gallbladder in situ, n = 11; P = .12). CONCLUSIONS: In the Chinese, cholecystectomy after endoscopic treatment of bile duct stones reduces recurrent biliary events and should be recommended.

A pseudoepidermoid cyst arising from exuberant squamous metaplasia of the gallbladder.

Squamous lesions of the gallbladder are uncommon. We report a case of a pseudoepidermoid cyst in a middle-aged woman arising on a background of chronic cholecystitis and cholelithiasis, which induced exuberant squamous metaplasia of the entire gallbladder mucosa, clinically mimicking a gallbladder tumor. To our knowledge, this is the first such reported case in the English literature.

Proteome analysis of human hepatocellular carcinoma tissues by two-dimensional difference gel electrophoresis and mass spectrometry.

Proteome analysis of human hepatocellular carcinoma tissues was conducted using two-dimensional difference gel electrophoresis coupled with mass spectrometry. Paired samples from the normal and tumor region of resected human liver were labeled with Cy3 and Cy5, respectively while the pooled standard sample was labeled with Cy2. After analysis by the DeCyder software, protein spots that exhibited at least a two-fold difference in intensity were excised for in-gel tryptic digestion and matrix-assisted laser desorption/ionization-time of flight mass spectrometry. A total of 6 and 42 proteins were successfully identified from the well- and poorly-differentiated samples, respectively. The majority of these proteins are related to detoxification/oxidative stress and metabolism. Three down-regulated metabolic enzymes, methionine adenosyltransferase, glycine N-methyltransferase, and betaine-homocysteine S-methyltransferase that are involved in the methylation cycle in the liver are of special interest. Their expression levels, especially, methionine adenosyltransferase, seemed to have a major influence on the level of S-adenosylmethionine (AdoMet), a vital intermediate metabolite required for the proper functioning of the liver. Recent work has shown that chronic deficiency in AdoMet in the liver results in spontaneous development of steatohepatitis and hepatocellular carcinoma, and hence the down-regulation of hepatic methionine adenosyltransferase in our hepatocellular carcinoma samples is in line with this observation. Moreover, when a comparison is made between the differentially expressed proteins from our human hepatocellular carcinoma samples and from the liver tissues of knockout mice deficient in methionine adenosyltransferase, there is a fairly good correlation between them.

A proteomic analysis of thioacetamide-induced hepatotoxicity and cirrhosis in rat livers.

Thioacetamide (TAA) administration is an established technique for generating rat models of liver fibrosis and cirrhosis. Oxidative stress is believed to be involved as TAA-induced liver fibrosis is initiated by thioacetamide S-oxide, which is derived from the biotransformation of TAA by the microsomal flavine-adenine dinucleotide (FAD)-containing monooxygense (FMO) and cytochrome P450 systems. A two-dimensional gel electrophoresis-mass spectrometry approach was applied to analyze the protein profiles of livers of rats administered with sublethal doses of TAA for 3, 6 and 10 weeks respectively. With this approach, 59 protein spots whose expression levels changed significantly upon TAA administration were identified, including three novel proteins. These proteins were then sorted according to their common biochemical properties and functions, so that pathways involved in the pathogenesis of rat liver fibrosis due to TAA-induced toxicity could be elucidated. As a result, it was found that TAA-administration down-regulated the enzymes of the primary metabolic pathways such as fatty acid beta-oxidation, branched chain amino acids and methionine breakdown. This phenomenon is suggestive of the depletion of succinyl-CoA which affects heme and iron metabolism. Up-regulated proteins, on the other hand, are related to oxidative stress and lipid peroxidation. Finally, these proteomics data and the data obtained from the scientific literature were integrated into an "overview model" for TAA-induced liver cirrhosis. This model could now serve as a useful resource for researchers working in the same area.

Identification of discriminators of hepatoma by gene expression profiling using a minimal dataset approach.

The severity of hepatocellular carcinoma (HCC) and the lack of good diagnostic markers and treatment strategies have rendered the disease a major challenge. Previous microarray analyses of HCC were restricted to the selected tissue sample sets without validation on an independent series of tissue samples. We describe an approach to the identification of a composite discriminator cassette by intersecting different microarray datasets. We studied the global transcriptional profiles of matched HCC tumor and nontumor liver samples from 37 patients using cDNA (cDNA) microarrays. Application of nonparametric Wilcoxon statistical analyses (P < 1 x 10(-6)) and the criteria of 1.5-fold differential gene expression change resulted in the identification of 218 genes, including BMI-1, ERBB3, and those involved in the ubiquitin-proteasome pathway. Elevated ERBB2 and epidermal growth factor receptor (EGFR) expression levels were detected in ERBB3-expressing tumors, suggesting the presence of ERBB3 cognate partners. Comparison of our dataset with an earlier study of approximately 150 tissue sets identified multiple overlapping discriminator markers, suggesting good concordance of data despite differences in patient populations and technology platforms. These overlapping discriminator markers could distinguish HCC tumor from nontumor liver samples with reasonable precision and the features were unlikely to appear by chance, as measured by Monte Carlo simulations. More significantly, validation of the discriminator cassettes on an independent set of 58 liver biopsy specimens yielded greater than 93% prediction accuracy. In conclusion, these data indicate the robustness of expression profiling in marker discovery using limited patient tissue specimens as well as identify novel genes that are highly likely to be excellent markers for HCC diagnosis and treatment.