Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0019204 (hepatocellular carcinoma)
 71,386 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Methapyrilene hydrochloride [2-[2-(dimethylamino)-ethyl)-2-thenylamino)pyridine monohydrochloride (CAS: 135-23-9)]-induced hepatocarcinogenesis was studied in male F344/NCr rats by sequential histologic, histochemical, and biologic methods. Methapyrilene hydrochloride was administered in the feed to rats at a concentration of 1,000 ppm for periods up to 89 weeks. Groups of rats were killed after 5, 10, 15, 29, 40, or 73 weeks of ingesting the carcinogen. Another group was allowed to live out their life-span. Hepatocellular eosinophilic foci and adenomas were seen after 10 and 15 weeks, respectively. Basophilic foci and adenomas were found after 29 and 40 weeks, respectively. Hepatocellular carcinomas developed in 5 of 10 rats at week 40, in 3 of 5 rats at week 73, and in 19 of 19 rats that lived out their life-span. Carcinomas arose within adenomas or as small in situ carcinomas. The histologic types included trabecular, adenocarcinoma, mixed, and solid poorly differentiated hepatocellular carcinomas. Eleven of the mixed and solid poorly differentiated carcinomas metastasized to the lung. Solid poorly differentiated hepatocellular carcinomas grew upon transplantation to the mammary fat pad of weanling F344 rats. Cholangiocarcinomas were found in 7 of 19 rats only in the life-span group. Mucous cholangiofibrosis was seen in all rats after 15 weeks. With the use of Regaud's mitochondrial stain, an increased cellular density of mitochondria was seen in some hepatocytes of peripheral and central lobular areas and in some hepatocellular carcinoma cells, but not in cells in many of the adenomas and foci. Cellular alpha-fetoprotein was found by immunoperoxidase staining in portions of hepatocellular carcinomas, but not in foci, adenomas, and nonneoplastic areas. The majority of hepatocytes in foci, adenomas, and hepatocellular carcinomas contained gamma-glutamyl transpeptidase. The findings suggest that multiple pathways may be followed in the development of methapyrilene-induced liver cancer that are similar to those found in rats exposed to many other hepatic carcinogens.
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PMID:A sequential study of methapyrilene hydrochloride-induced liver carcinogenesis in male F344 rats. 658 58

Preneoplastic and neoplastic liver cell lesions, induced by EHEN (N-ethyl-N-hydroxyethylnitrosamine) in rats, were investigated to establish the numbers of simultaneously expressed altered enzyme phenotypes within the lesion cells. The lesions were divided into 5 classes on the basis of altered expression in one or more of the following 5 enzymes: glutathione S-transferase placental form, glucose-6-phosphate dehydrogenase, glucose-6-phosphatase, adenosine triphosphatase, and gamma-glutamyl transpeptidase. Class 1 lesions contained cells expressing one altered enzyme. Similarly, class 2, 3, 4 and 5 lesions had cells simultaneously expressing 2, 3, 4, and 5 enzyme alterations, respectively. Four histopathological categories of lesions, ACF (altered cell foci) (274 lesions), HN (hyperplastic nodules) (47 lesions), HCC (hepatocellular carcinomas) (99 lesions) and THC (transplanted hepatocellular carcinomas) (5 lesions) were studied. Proliferation potential was assessed in terms of 5-bromo-2'-deoxyuridine (BrdU) incorporation. The distribution profiles of classes 1 to 5 showed a clear reciprocal change from low class (1 to 2 enzymes) predominance in ACF to high class (4 to 5 enzymes) predominance in HN. Increase of BrdU labeling indices was clearly correlated with progression from HN to HCC. Only a small population of class 5 ACF showed a high BrdU labeling index, indicating particular potential for further development. Thus, the stages of EHEN-induced neoplasia were found to be characterized by gradual increase in the number of altered enzyme phenotypes, with acquisition of proliferative potential being associated with further progression towards malignant conversion.
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PMID:Number of simultaneously expressed enzyme alterations correlates with progression of N-ethyl-N-hydroxyethylnitrosamine-induced hepatocarcinogenesis in rats. 790 86

Serum gamma-glutamyl transpeptidase (gamma-GTP) was separated into four fractions by using wheat germ agglutinin (WGA) affinity electrophoresis. By two-dimensional analysis using gel filtration combining with affinity electrophoresis with WGA, anti-alpha 1-lipoprotein antiserum or anti-beta-lipoprotein antiserum, properties of each fraction were identified as a high molecular WGA affinity fraction (HM), a relatively high molecular beta-lipoprotein binding fraction (beta-LP), an intermediate molecular alpha-lipoprotein binding fraction (alpha-LP) and a low molecular fraction (LM). Quantitative alterations in each fraction of gamma-GTP in the serum of patients with various liver diseases and gall stones (GS) were also examined. In patients with hepatocellular carcinoma (HCC), the HM fraction was more increased compared with those in patients with non-alcoholic liver cirrhosis (LC) and chronic hepatitis (CH). The rate of HM fraction was correlated with total activity of serum gamma-GTP in HCC patients. In alcoholic liver disease (ALD), no remarkable differences of the rate of each gamma-GTP fraction were shown among alcoholic LC, alcoholic hepatitis, alcoholic CH and fatty liver patients. It was, however, shown that the rate of the LM fraction decreases and the HM fraction increases gradually in accordance with an increase in serum gamma-GTP activity in ALD. These data indicate that serum gamma-GTP isoenzymes can be separated clearly into four fractions by using WGA affinity electrophoresis, the HM fraction of serum gamma-GTP is relatively increased in HCC patients, and detection of the HM fraction may be useful to diagnose HCC, although it can be increased in ALD patients with high serum gamma-GTP activity.
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PMID:Separation and identification of serum gamma-glutamyl transpeptidase isoenzymes by wheat germ agglutinin affinity electrophoresis: a basic analysis and its clinical application to various liver diseases. 790 77

The clinical findings in 33 patients with progressive familial intrahepatic cholestasis (PFIC) are presented. Symptoms developed almost invariably before 6 months of age with severe pruritus and moderate jaundice. Other clinical findings included wheezing and nosebleeds, fat-soluble vitamin deficiency states, and cholelithiasis. Lower values for gamma-glutamyl transpeptidase, averaging 15 IU/L before the administration of phenobarbital, and cholesterol, which averaged 156 mg/dl, are helpful in distinguishing PFIC from other pediatric cholestatic liver diseases. Autosomal recessive inheritance is probable. Twenty-six patients are alive at 12.9 +/- 6.7 years of age, all having had successful surgical treatment, either partial biliary diversion (n = 17) or orthotopic liver transplantation (n = 10). Seven patients died at a mean age of 3.9 +/- 2.4 years, as a result of liver failure in two, hepatocellular carcinoma in two, and complications of liver transplantation in three.
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PMID:Clinical and biochemical findings in progressive familial intrahepatic cholestasis. 791 66

In the small intestine and in HTC hepatoma cells, the gamma-glutamyl transpeptidase (GGT) single-copy gene is transcribed into a 2.5 kb and a 2.2 kb mRNA. Cloning of the GGT cDNA sequences from HTC cells demonstrates that the 2.5 kb mRNA (mRNA(IV-1)) differs from the other rat GGT transcripts by a 371-base unique leader sequence which maps in the gene as 2 separate exons upstream of the 3 promoters which have been previously characterized. We established that the transcription of these two mRNAs is initiated on a new promoter (promoter IV) and occurs in the small intestine, in the epididymis, and in some hepatoma cells. The primary transcript initiated on GGT promoter IV is then alternatively spliced into the 2.5 kb mRNA(IV-1) or the 2.2 kb mRNA(IV-2) which is shorter in its 5'-untranslated sequence. The rat GGT gene exhibits a complex transcriptional organization leading to the transcription of five mRNAs from four independent promoters in a tissue-specific manner. The expression of the GGT promoter IV in the HTC hepatoma cells as well as in the small intestine could reveal that the HTC-transformed cells originate from liver precursor cells which still have the capacity to evolve toward different lineages. Thus, the GGT promoter IV will be valuable to isolate factors involved in the differentiation and carcinogenic processes.
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PMID:Expression of the rat gamma-glutamyl transpeptidase gene from a specific promoter in the small intestine and in hepatoma cells. 791 67

From the early stage of pancreatic adenocarcinoma in hamsters and also of hepatocellular carcinoma in rats, induced by treatment with N-nitrosobis (2-oxopropyl)amine and 3'-methyl-dimethylaminoazobenzene, respectively, hepatic levels of metallothionein (MT) were found to be continuously elevated. In the hepatoma-induced rats, this elevation preceded that of serum gamma-glutamyl transpeptidase activity, a marker enzyme for hepatocellular carcinoma. These results indicate that, in the course of chemical carcinogenesis, the elevation of hepatic MT level occurred and continued from the early stage of carcinogenesis. This type of elevation of hepatic MT level was also observed in lung metastasis-induced mice. On the other hand, in rats with pancreatitis caused by the administration of deoxycholate, the hepatic level of MT rose only transiently.
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PMID:Elevation of hepatic levels of metallothionein during experimental carcinogenesis. 794 3

This work details the histologic findings in 84 liver biopsy specimens from 28 patients with progressive familial intrahepatic cholestasis (PFIC), who met the clinical criteria of early onset of chronic unremitting cholestasis, exclusion of any known metabolic or anatomic etiology, and low serum gamma-glutamyl transpeptidase (GGTP) values. Hepato-canalicular cholestasis and disruption of the liver cell plate arrangement were early, uniform findings, and giant cell transformation was found in 56% of initial biopsies. Duct loss was a prominent finding; 70% of patients had ductal paucity, and many had abnormal bile duct epithelium, suggesting degeneration. Fibrosis was seen in the samples from 16 patients, including bridging fibrosis in specimens obtained from six patients during the first 2 years of life. Proliferating ductules at the margins of portal tracts increased as fibrosis progressed and were especially prominent in end-stage histology. Cirrhosis developed in nine of these patients and had a characteristic histologic pattern, consisting of biliary cirrhosis with diffuse stellate lobular fibrosis associated with severe cholestasis and pseudoacinar transformation. Mallory hyalin and hepatocellular carcinoma were observed in materials from some patients with advanced cirrhosis. The constellation of histologic findings in PFIC forms a recognizable pattern, and the liver histology appears to have a predictable progression.
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PMID:Histologic pathology of the liver in progressive familial intrahepatic cholestasis. 801 59

We describe an improved technique which allows the analysis of enzyme reaction kinetics for gamma-glutamyl transpeptidase (gamma-GT) by flow cytometry. This is technically difficult because of the location of the enzyme on the external surface of the cell membrane leading to the rapid escape of the product. The reaction is determined by monitoring the conversion of gamma-glutamyl aminomethylcoumarin to aminomethylcoumarin. Reaction kinetics are described for BL8 hepatocyte and JB1 hepatoma cells lines, together with inhibition kinetics for the active site-directed glutamine analogue L-(alpha-S,5S)-alpha-amino-3-chloro-4,5-dihydro-5-isoxazoleacetic acid. We show that it is possible to follow the reaction dynamics in a heterogeneous mixture of BL8 and JB1 cells allowing discrimination of the two cell types based on gamma-GT activity. Improvements for further optimizing the assay of this important enzyme are suggested.
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PMID:Can flow cytoenzymology be applied to measure membrane-bound enzyme kinetics? Assessment by analysis of gamma-glutamyl transpeptidase activity. 810 25

Many studies concerning gamma-glutamyl transpeptidase (GGTP) in hepatocellular carcinoma (HCC) have suggested that changes in hepatic GGTP expression may be closely related to the development of HCC. However, its mechanisms are not well known, and genomic analysis of the specific GGTP to HCC is also lacking. Recently, the human GGTP complementary DNA (cDNA) sequences from fetal liver, placenta, and HepG2 cells have been published. In the present study, we sought to clarify the distribution of the GGTP messenger RNA (mRNA) molecular species in human liver and determine whether alterations in GGTP mRNA expression occur upon the development of HCC. The specific primer sets for reverse-transcription polymerase chain reaction (PCR) corresponding to the 5'-noncoding human GGTP mRNA of fetal liver (type A), HepG2 cells (type B), and placenta (type C) were prepared. Oligonucleotide probes specific for each type of mRNA were also synthesized. Liver tissues were obtained from patients with or without HCC, and total RNA was extracted. Total RNA was also extracted from various organs obtained from one male patient upon autopsy. Types of GGTP mRNAs were analyzed using type-specific primer sets and oligonucleotide probes. The types of GGTP mRNA varied in different organs. In normal liver and diseased liver without HCC, the main type of GGTP mRNA was type A. The expression was monogenic in most cases but was polygenic in some cases. In the polygenic cases, type C was common, but type B was found occasionally. On the other hand, type B was predominant in cancerous tissues with HCC. In noncancerous tissues of livers with HCC, the main types were types A and B. The prevalence of type B was significantly higher in both cancerous and noncancerous tissues of livers with HCC than in livers without HCC. The prevalence of type A in cancerous tissue, but not in noncancerous tissue, was significantly lower than in livers without HCC. These results strongly suggested that the GGTP mRNA expression in human liver may shift from type A to type B during the development of HCC. The high prevalence of type B in noncancerous tissues suggested that the shift of the GGTP mRNA may occur from the preneoplastic stage of hepatocytes.
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PMID:Detection of a unique gamma-glutamyl transpeptidase messenger RNA species closely related to the development of hepatocellular carcinoma in humans: a new candidate for early diagnosis of hepatocellular carcinoma. 862 Nov 39

The understanding of the structure and function of gamma-glutamyl transpeptidase (GGT) has been hindered by the difficulty of obtaining large quantities of functional enzyme. A recombinant baculovirus, encoding the human hepatoma cell (Hep G2) GGT, was easily purified using a histochemical procedure to reveal GGT activity. Infected insect cells synthesized a large amount of enzymatically active GGT representing up to 10% of the total cell extract protein. The GGT specific activity of the infected cells was 13 units per mg of protein which is the highest GGT expression level reported to date, 260-times more than in Hep G2 cells. The recombinant protein displayed an apparent molecular mass (M(r), 58,000 for the heavy subunit), immunoreactivity and catalytic features similar to those of the native protein. The high-level expression of functional GGT should provide an excellent tool to further study the structure-function relationships of the protein.
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PMID:High-level expression of functional human gamma-glutamyl transpeptidase using the baculovirus system. 872 10


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