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)

Hereditary Hemochromatosis (HFE) is one of the most common inherited disorders with an estimated frequency of homozygous patients of 0.002-0.0045. The disease is characterized by increased intestinal iron absorption and progressive iron overload. Affected subjects show clinical symptoms of parenchymal organ damage after the third-fourth decade of life and have a 200 fold increased risk of developing hepatocellular carcinoma. Early diagnosis and treatment prevent complications and may normalize life expectancy of patients. The biochemical and genetic defects leading to progressive iron accumulation are still unknown, but the HFE gene is tightly linked to HLA complex on the short arm of chromosome 6. Utilizing HLA serotypes and the study of several polymorphic markers of 6p21, a linkage analysis of the disease locus was performed in a series of Italian hemochromatosis families. The data obtained by linkage analysis and the study of a family with a double recombinant allowed us to better define the HFE gene location with respect to HLA-class I A and F loci.
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PMID:Linkage analysis of 6p21 polymorphic markers and the hereditary hemochromatosis: localization of the gene centromeric to HLA-F. 851 96

Genetic haemochromatosis (GH) is one of the most common hereditary diseases, with a prevalence of 1-5/1000 in the Western world. In 90 per cent of cases a mutation is found in an MHC-class-like gene designated HFE, involving a substitution at position 282 of the HFE protein and resulting in defective binding of beta(2)-microglobulin. Animals with beta(2)-microglobulin deficiency develop iron overload, indicating this protein to be involved in the regulation of iron metabolism. Hepatic iron overload results in increased production of oxygen free radicals and peroxidation of membrane lipids, thus causing damage to lysosomes, mitochondria and the endoplasmic reticulum. These cellular events may progress to cell death, fibrogenesis, and the development of liver cirrhosis which is associated with a 200-fold increase in risk of hepatocellular carcinoma. In addition to the risk of diabetes, arthralgia, cardiac arrhythmia, pituitary insufficiency and hypogonadism, iron excess is also associated with aggravation of the cytotoxic effects exerted on hepatocytes by other agents such as alcohol or hepatotrophic viruses. The treatment of iron overload in GH consists of weekly venesection until the serum ferritin level is normalized, followed by maintenance therapy. Survival rates are normal if the disease is detected and treated before complications have developed.
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PMID:[Defective iron metabolism in genetic hemochromatosis. The mechanisms remain unknown in spite of genetic advances]. 972 62

Hemochromatosis is the most common single gene disorder in Caucasian populations. Regulation of iron balance by intestine is impaired, leading to a widespread deposition of iron, and the disease is associated with an increased risk of hepatocellular carcinoma. Typically the excess of iron treated by phlebotomies is performed in our Blood Center. In 1996 an original paper identifying HFE as a strong candidate gene for hemochromatosis was published and two mutations were described (C282Y and H63D). The former results in a cysteine to tyrosine substitution at amino acid 282 and was found in different patient populations up to 80-90% of patients homozygous for the C282Y mutation. The frequency of the second variant H63D is also increased in hemochromatosis patients but its penetrance is probably not complete. Assessing clinical implications is a new way of identifying patients at risk for this frequent and probably underdiagnosed disease, and important because treatment by venesections is safe with a proven benefit in preventing development of the disease. Four hundred and eighty patients were included in our study and we have shown in this work a correlation between the genotype and the phenotypic presentation of the disorder, with patients homozygous for the C282Y mutation having a greater excess of iron.
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PMID:[The hemochromatosis gene (HFE). Molecular analysis--diagnostic applications]. 978 68

A 66-year-old white man had a hepatic resection for a 6-cm well-differentiated hepatocellular carcinoma which had developed in a non-cirrhotic liver. The only risk factors found were heavy drinking, smoking and heterozygosity for the C282Y mutation of the HFE gene. The liver was mildly fibrotic and overloaded with iron. It also contained numerous iron-free hepatocellular lesions from <1 to 10 mm, suggesting a premalignant change. These lesions were of three types: (i) iron-free foci, (ii) hyperplastic nodules and (iii) dysplastic nodules with severe dysplasia or even foci of well-differentiated grade I hepatocellular carcinoma. This observation suggests the possibility of malignant transformation of the liver in the newly-described syndrome of iron overload and normal transferrin saturation. It also illustrates the multistep process of carcinogenesis in the non-cirrhotic liver.
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PMID:Premalignant lesions and hepatocellular carcinoma in a non-cirrhotic alcoholic patient with iron overload and normal transferrin saturation. 1006 14

The discovery of the C282Y and H63D point mutations in the hereditary hemochromatosis-associated HFE gene allows us to study the molecular basis of congenital and acquired iron overload disorders. In hereditary hemochromatosis an increased frequency of the C282Y and, to a lesser extent, of the H63D mutations has been established, but their role in other conditions associated with iron overload and their prevalence in the normal population are still under investigation. We sought to determine the presence of such mutations, and their possible involvement in the multi-step neoplastic transformation of the hepatocytes, in patients diagnosed with hepatocellular carcinoma, a frequent complication of iron-induced liver cirrhosis occurring in untreated hereditary hemochromatosis subjects. The frequency of the C282Y and H63D mutations was determined in DNA from 12 patients with hepatocellular carcinoma and with no clinical signs of hereditary hemochromatosis. The frequency of the mutations was also determined in 130 normal subjects. A germline C282Y mutation was found in none of the hepatocellular carcinoma patients; the frequency of the H63D mutation was not increased, compared to the 130 controls. The allele frequencies of the C282Y and H63D mutations in the normal population were 0.042 and 0.185, respectively. In conclusion, we suggest that the hereditary hemochromatosis-related mutations of the HFE gene do not play a significant role in the pathogenesis of hepatocellular carcinoma.
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PMID:Mutations of the HFE gene and the risk of hepatocellular carcinoma. 1066 Apr 82

HFE is a MHC class 1-like protein that is mutated in hereditary hemochromatosis. In order to elucidate the role of HFE protein on cellular iron metabolism, functional studies were carried out in human hepatoma cells (HLF) overexpressing a fusion gene of HFE and green fluorescent protein (GFP). The expression of HFE-GFP was found to be localized on cell membrane and perinuclear compartment by fluorescent microscopy. By co-immunoprecipitation and Western blotting, HFE-GFP protein formed a complex with endogenous transferrin receptor and beta(2)-microglobulin, suggesting that this fusion protein has the function of HFE reported previously. We then examined the (59)Fe uptake and release, and internalization and recycling of (125)I-labeled transferrin in order to elucidate the functional roles of HFE in the cell system. In the transfectants, HFE protein decreased the rate of transferrin receptor-dependent iron ((59)Fe) uptake by the cells, but did not change the rate of iron release, indicating that HFE protein decreased the rate of iron influx. Scatchard analysis of transferrin binding to HFE-transfected cells showed an elevation of the dissociation constant from 1.9 to 4. 3 nM transferrin, indicating that HFE protein decreased the affinity of transferrin receptor for transferrin, while the number of transferrin receptors decreased from 1.5x10(5)/cell to 1. 2x10(5)/cell. In addition, the rate of transferrin recycling, especially return from endosome to surface, was decreased in the HFE-transfected cells by pulse-chase study with (125)I-labeled transferrin. Our results strongly suggest an additional role of HFE on transferrin receptor recycling in addition to the decrease of receptor affinity, resulting in the reduced cellular iron.
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PMID:Overexpression of hemochromatosis protein, HFE, alters transferrin recycling process in human hepatoma cells. 1077 Oct 90

Genetic hemochromatosis is an autosomal recessive disease, characterized by an increased iron absorption, leading to progressive iron overload. The fully expressed phenotype comprises fatigue, skin pigmentation, liver disease with hepatomegaly, cirrhosis and hepatocellular carcinoma, and diabetes. Arthralgias are frequent, cardiopathy or impotence may occur. This presentation is now unfrequent with earlier diagnosis, and patients are often asymptomatic--with only biochemical expression--or pauci-symptomatic (mild fatigue, arthralgias or increased transaminases). Transferrin saturation is always increased. Serum ferritin is proportional to iron burden. Diagnosis is now easy, since most patients are homozygote for the C282Y mutation of the HFE gene. Liver biopsy can be useful to quantify iron overload and assess liver fibrosis. The disease can be lethal due to liver disease, carcinoma or heart disease, but life expectancy goes to normal if patients are treated before the occurrence of cirrhosis. Treatment relies on regular venesections. Familial screening is essential.
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PMID:[Diagnosis and treatment of genetic hemochromatosis]. 1086 97

Heavy iron overload, as occurs in primary and secondary hemochromatosis, may cause fibrosis of parenchymal organs, including the heart, liver, and pancreas, and it is a risk factor for the development of hepatocellular carcinoma. Recent evidence indicates that lesser degrees of hepatic iron deposition are also risk factors for nonhemochromatotic liver disease. For example, several recent studies showed extraordinarily high prevalences (about 60% to 75%) of HFE mutations in patients with porphyria cutanea tarda and significantly increased prevalences of these mutations in patients with nonalcoholic steatohepatitis from Australia and the United States. It is less well established that the prevalence of the HFE mutations is increased in alcoholic liver disease and in chronic viral hepatitis, but in both conditions, patients harboring one of these mutations, especially C282Y, are more likely to have advanced hepatic fibrosis or cirrhosis. Thus, these mutations both incite and exacerbate nonhemochromatotic liver disease. In this review, we summarize current knowledge of these associations and emphasize important unresolved questions that require further study.
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PMID:Role of HFE gene mutations in liver diseases other than hereditary hemochromatosis. 1098 Sep 24

Iron accumulation in the liver is frequently observed in hepatic diseases whatever their etiologies. In the majority of cases, there is no true overload, and iron accumulation corresponds to deposits in macrophages secondary to iron release from damaged hepatocytes. More rarely, namely in severe cirrhosis, there is a true overload, which is probably related to iron intestinal hyperabsorption. In such case, the site of iron excess is hepatocytic. Except for hemochromatosis, mutations of HFE gene do not play a major role in iron overload. In chronic liver diseases, iron overload could favor the development of hepatocellular carcinoma, even in the absence of cirrhosis.
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PMID:[Iron overload and liver diseases (except for hemochromatosis and dysmetabolic hepatosiderosis]. 1098 43

Most experimental and human data support the hypothesis that iron overload is a risk factor for cancer in general and liver cancer in particular. This oncogenic effect could be explained by an overproduction of reactive oxygen species and free radicals. In cirrhosis due to genetic haemochromatosis (homozygosity for the mutation C282Y in the HFE gene) there is an increase incidence of hepatocellular carcinoma. Few cases have been reported in genetic haemochromatosis with iron overload but without cirrhosis. In hepatocellular carcinoma developed in non cirrhotic liver there is a mild iron overload in more than 50% of cases. In these patients heterozygous and compound C282Y mutations are found in 36%. In black Africans, iron overload genetically determined but not linked to mutations in the HFE gene increases also the risk of hepatocellular carcinoma. Among the many factors (viral hepatitis, alcohol, tobacco etc.) which play a role in hepatic carcinogenesis, iron overload is probably an important one and therefore should be treated.
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PMID:[Iron overload and cancer]. 1098 44


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