Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0023890 (cirrhosis)
 42,195 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Sinusoidal Ito cells (stellate or fat-storing cells) undergo excessive cellular proliferation before the establishment and progression of hepatic fibrosis and cirrhosis. Retinoic acid and transforming growth factor beta (TGF beta) both inhibit Ito-cell [3H]thymidine incorporation in serum-containing media. Serum-induced mitogenicity was dependent on platelet-derived growth factor (PDGF). Additionally, pre-treatment of Ito cells with retinoic acid and TGF beta blocked PDGF-induced cell proliferation. TGF beta, but not retinoic acid, diminished PDGF-receptor and smooth-muscle alpha-actin abundance.
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PMID:Retinoic acid and transforming growth factor beta differentially inhibit platelet-derived-growth-factor-induced Ito-cell activation. 165 42

We studied a cell-cell interaction via transforming growth factor-beta (TGF-beta ) between liver stellate cells (SCs) and parenchymal cells (PCs) using co-cultures of rat primary SCs and PCs. Both TGF-beta added exogenously to the culture medium, and TGF-beta produced endogenously from SCs after stimulation with retinoic acid (RA), suppressed the production and secretion of albumin from PCs. This effect occurred at the translational level, but not at the transcriptional level; TGF-beta, as well as SC culture medium conditioned by RA, did not affect the albumin mRNA levels, but decreased the biosynthesis of [35-S]methionine-labeled albumin without altering its post-translational degradation rate. These results suggest that TGF-beta generated from SCs facilitates the development of liver cirrhosis not only by inducing the production of fibrotic components from SCs, but also by impairing the function of the surrounding PCs.
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PMID:Retinoic acid-stimulated liver stellate cells suppress the production of albumin from parenchymal cells via TGF-beta. 863 1

Chronic and excessive ethanol consumption is associated with cellular proliferation, fibrosis, cirrhosis, and cancer of the liver. The critical event in early alcohol-induced hepatic injury is an alcohol-induced activation (cell proliferation and increased fibrogenesis) of hepatic stellate cells. However, the mechanisms by which alcohol causes proliferative activation in hepatic stellate cells have not been identified. An important characteristic of alcohol-induced injury is impaired vitamin A nutritional status. The demonstration that retinoic acid is the most physiologically active derivative of vitamin A and the discovery of retinoic acid receptors provide a mechanistic basis for understanding the actions of vitamin A and alcohol on hepatic cell proliferation. Recent studies have demonstrated that chronic alcohol intake can reduce hepatic retinoic acid concentrations, diminish retinoid signaling, and enhance activator protein-1 (AP-1 (c-Jun and c-Fos)) expression in rat liver. These are the possible biochemical and molecular mechanisms whereby ethanol ingestion results in hepatic stellate cell proliferative activation and hepatic fibrogenesis.
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PMID:Chronic alcohol intake interferes with retinoid metabolism and signaling. 1007 3

Recent improvements on the therapeutical management of hepatocellular carcinoma are revised with special attention to evaluate the role of surgery for the disease. Considering that definitive surgical intervention is not feasible in most cases because of extreme tumor extension, multiplicity of tumor foci, and associated advanced liver cirrhosis at the time of diagnosis, others forms of treatment are listed, such as transcatheterarterial chemoembolization, percutaneous ethanol and acetic acid injections, and chemotherapy only to a small portion of patients with no indication for standard treatments. The emerging role of retinoic acid metabolism blocking agents, was examined and may offer a significant new potential treatment for cancer, inclusive the possibility of combining other anticancer drugs with exogenous retinoids or modulation of endogenous retinoids as a real opportunity to advance our ability to treat or prevent human cancer effectively Octreotide, nitrosamine and other drugs are analyzed and is concluded that improves survival and is a valuable alternative in the treatment of inoperable hepatocellular carcinoma. The potential role of intersticial laser coagulation for patients with irresectable hepatic tumors was investigated, and in terms of experience, it has now been developed sufficiently to study its effect on these patients survival. The homeostatic control of angiogenesis and its influences on the tumor growth and for migration of metastatic cells, was focused in this concise review, given that hepatocytes are the source of much of the precursor pool, regulation of angiogenesis may be regarded as a new liver function with important consequences for tissue repair and cancer. Early hepatocellular carcinoma and its recognition in routine clinical practice contributes to improved patients survival. Recombinant-Interferon-alpha therapy surely prevents, the development of cirrhosis or hepatocellular carcinoma in about one-third of patients, with chronic hepatitis C, with sustained response. Finally, in individuals with life-threatening liver disease, such as those with cirrhosis and hepatocellular carcinoma, the liver transplantation, must be considered, besides controversial, however, with increasing experience the results of the procedure in these patients have improved, and may offer a better long-term survival than liver resection.
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PMID:[Hepatocellular carcinoma. Part 2. Treatment]. 1114 17

Hepatocyte growth factor (HGF) was purified as a potent mitogen for rat hepatocytes in primary culture and is believed to be the most physiological hepatotrophic factor that triggers liver regeneration. HGF is one of the largest disulfide-linked cytokines, consisting of a 60-kDa heavy chain and a 35-kDa light chain. Human HGF is synthesized as a single polypeptide chain precursor of 728 amino acid residues that has an appreciable homology with plasminogen, and it is processed proteolytically to release an N-terminal signal peptide of 31 amino acids and to generate an active heterodimer after secretion. The novel serine protease HGF activator and urokinase-type plasminogen activator (u-PA) are responsible for the latter extracellular processing. HGF stimulates the proliferation of rat hepatocytes in primary culture at concentrations as low as 10 pM. It also stimulates the growth of various epithelial cells, endothelial cells, and some kinds of mesenchymal cells. HGF inhibits the proliferation of several tumor cell lines and induces apoptosis of some of them. It also has motogenic, morphogenic, anti-apoptotic, angiogenic, and immunoregulatory activities. The receptor of HGF is the product of c-met proto-oncogene with tyrosine kinase activity that mediates the transduction of multiple biological signals of HGF. During liver regeneration, HGF gene expression in the liver, spleen, and lung and HGF levels in the blood and liver increase prior to the induction of liver DNA synthesis. Liver regeneration is markedly inhibited by continuous administration of a neutralizing anti-HGF antibody. HGF production in cultured cells is induced by PKC-activating agents, cAMP-elevating agents, PKA-activating agents, growth factors, and inflammatory cytokines; and it is inhibited by TGF-beta, glucocorticoids, 1,25-dihydroxyvitamin D3, and retinoic acid. There are many reports on potential application of HGF as a therapeutic agent for organ diseases that are difficult to cure such as liver cirrhosis, chronic renal failure, pulmonary fibrosis, myocardial infarction, and arteriosclerosis obliterans utilizing its potent growth-stimulating activity for a wide variety of cells. ELISA kits for assays of serum and plasma HGF levels are clinically used to prognosticate the development of fulminant hepatic failure.
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PMID:[Function and regulation of production of hepatocyte growth factor (HGF)]. 1206 Nov 40

Hepatic stellate-cell lipidosis due to hypervitaminosis A can lead to cirrhosis, which can be averted by restricting vitamin A intake. Other causes, including the use of synthetic retinoids, have been postulated. We studied the frequency and etiology of stellate-cell lipidosis in patients undergoing liver biopsy for reasons other than vitamin A abuse. Fourteen cases (1.1%) were identified retrospectively among 1,235 nontransplant liver biopsy specimens examined from January 1995 through December 1999. Diagnostic criteria included the following: lipid-laden cells in the space of Disse; small, dark, crescent-shaped nuclei with inconspicuous nucleoli; and wispy cytoplasmic strands separating fat droplets. Patient details, reason for biopsy, and medication use were studied. Reasons for biopsy included hepatitis C (10 cases), abnormal liver enzyme levels (2 cases), methotrexate use (1 case), and alcohol abuse (1 case). Hypervitaminosis A was not suspected clinically in the 5 patients who used oral vitamin A or 3 who used topical tretinoin (Retin-A). In 6 patients, no cause of stellate-cell lipidosis was discerned. Stellate-cell lipidosis should be reported to alert clinicians to a potentially preventable form of liver injury.
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PMID:Stellate-cell lipidosis in liver biopsy specimens. Recognition and significance. 1257 96

We here review therapeutic application of a synthetic analog of retinoids (vitamin A and its derivatives), named acyclic retinoid (AR), towards chemoprevention of hepatocellular carcinoma (HCC), and its underlying molecular mechanisms. A high incidence of post-therapeutic recurrence has become a major determinant of the prognosis of HCC, especially in the patients of hepatitis virus-infected cirrhosis. Oral supplementation of AR successfully prevented the recurrence of HCC, associated with a disappearance in serum levels of lectin-reactive alpha-fetoprotein (AFP-L3), a marker of occult cancer clones in the liver, suggesting eradication of latent malignant clones from patients' liver. This led us a novel concept of 'clonal deletion' with AR as an agent that is conceptually similar to cancer chemotherapy. HCC in cirrhotic patients contains lower levels of endogenous retinoids and simultaneously is insensitive to retinoic acid (RA) because of malfunction of its nuclear receptor, retinoid X receptor alpha (RXRalpha). In HCC tissues, RXRalpha is constitutively phosphorylated by the action of extracellular signal-regulated kinase (Erk), thereby losing its transactivation activity and becoming resistant to degradation via ubiquitin/proteasome pathway. This leads to accumulation of phospho-inactivated RXRalpha, that functions as a dominant negative receptor and interferes with transactivation by remaining normal RXRalpha. AR but not natural RA prevents phosphorylation of RXRalpha and restores the function of RXRalpha via down-regulating Ras/Erk system, making HCC cells sensitive to the endogenous ligand, 9-cis-RA. This may link to both caspase-dependent and -independent apoptosis of the cancer cells via induction of growth suppressor(s) such as p21CIP1 and/or apoptosis inducer(s) including tissue transglutaminase. AR also enhances the sensitivity of HCC cells to interferons-alpha and -beta, and thereby indirectly promotes apoptosis induced by these interferons. In summary, our clinical experience and basic research together provide a strong rationale to use AR in the chemoprevention of HCC.
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PMID:Acyclic retinoid in the chemoprevention of hepatocellular carcinoma (review). 1501 Aug 15

More than 18 million adults in the United States abuse alcohol, a prevalence 5 times higher than that of hepatitis C. Chronic alcohol use of greater than 80 g/day for more than 10 years increases the risk for hepatocellular carcinoma (HCC) approximately 5-fold; alcohol use of less than 80 g/day is associated with a nonsignificant increased risk for HCC. The risk for HCC in decompensated alcohol induced cirrhosis approaches 1% per year. The risk does not decrease with abstinence, and HCC can occur in a noncirrhotic liver. Alcohol use in chronic hepatitis C doubles the risk for HCC as compared with the risk in hepatitis C alone. Furthermore, there may be synergism between alcohol and hepatitis C in the development of HCC, and in these patients HCC may occur at an earlier age and the HCC may be histologically more advanced. Studies in the United States and Italy suggest that alcohol is the most common cause of HCC (accounting for 32%-45% of HCC). The mechanisms by which alcohol causes HCC are incompletely understood, but may include chromosomal loss, oxidative stress, a decreased retinoic acid level in the liver, altered DNA methylation, and genetic susceptibility. Alcohol use is increasing in many countries, suggesting that alcohol will continue to be a common cause of HCC throughout the world.
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PMID:Alcohol and hepatocellular carcinoma. 1550 8

The changes in retinoid metabolism have been documented in liver cirrhosis. However, the dynamic alterations in levels of this vitamin between circulation and liver during development of the liver cirrhosis are not well understood. The aim of this study was to measure retinoids in the liver and circulation in parallel, during and after development of cirrhosis induced by carbon tetrachloride and thioacetamide. Retinoid levels were measured by HPLC. A decrease in retinaldehyde and total retinol, together with an increase in retinoic acid was evident in liver from both carbon tetrachloride or thioacetamide treated rats within a month after initiation of treatment. Activity of enzymes involved in retinoid metabolism such as retinaldehyde oxidase, retinaldehyde dehydrogenase, and retinaldehyde reductase were decreased in the liver. In parallel, levels of retinol and retinaldehyde in the serum were increased while retinoic acid was decreased. This study indicates that during development of cirrhosis, there is reciprocal transfer of retinoid metabolites between the circulation and the liver.
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PMID:Retinoid metabolism during development of liver cirrhosis. 1624 80

The strategy to prevent liver carcinogenesis consists of: (i) antiviral modalities such as vaccination, lamivudin, and interferon; (ii) anti-inflammatory modality; and (iii) chemoprevention using such compounds as retinoid analog and vitamin K. Cancer chemoprevention is defined as an approach where natural or synthetic chemical compound works to arrest or reverse premalignant cells by using physiological pathways. As a consequence, such a clone of premalignant cells is eradicated (clonal deletion) by differentiation induction or apoptosis, and thus the process toward the development of clinically detectable cancer is disrupted. A particularly effective candidate target of chemoprevention in liver diseases is an advanced stage of chronic hepatitis, that is supposed to contain transformed hepatocyte clone(s); that is, primary prevention from liver cirrhosis and prevention of recurrent and second primary hepatocellular carcinoma following the treatment of the initial cancer. Retinoid is a collective term of vitamin A analog that binds to nuclear retinoid receptors;retinoic acid receptors (RAR) and retinoid X receptors (RXR). After ligand coupling, these receptors form homo- or heterodimers, bind to the response element (RARE or RXRE) upstream of the target gene, and regulate the gene expression as a transcriptional factor. Biological phenotypes of such transcriptional regulation by retinoid include cellular differentiation, tissue morphogenesis, and programmed cell death (apoptosis). Due to these functions, retinoid analogs are clinically tried to prevent/treat carcinoma in a wide variety of organs including head and neck cancer, uterine cervical cancer, certain leukemia and liver cancer. In this article, clinical trials of retinoid analog to inhibit second primary hepatoma, supposed molecular mechanism of the action of the compound, and aberrant metabolism of RXR and its role in liver carcinogenesis are briefly reviewed.
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PMID:Chemoprevention of liver carcinogenesis with retinoids: Basic and clinical aspects. 1787 99


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