Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0019209 (hepatomegaly)
 5,798 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Cyclin D1 is a known oncogene and a key regulator of cell cycle progression. Amplification of the cyclin D1 gene and its overexpression have been associated with aggressive forms of human hepatocellular carcinoma (HCC). In this study, two independent lines of transgenic mice have been generated that express cyclin D1 under the control of the rat liver fatty acid binding protein promoter. This transgene specifically directs expression in the liver and the intestines. RNA and protein analysis demonstrated increased expression of the cyclin D1 gene product in the liver and bowel when compared with wild-type siblings. Both transgenic lines developed progressive liver disease. Examination of H&E stained sections of the liver and bowel revealed hyperplastic changes in the liver by 3 months of age. By 6 months of age, transgenic mice had obvious hepatomegaly and histological evidence of dysplasia in the liver. These early changes were significantly more dramatic in male animals when compared with female animals. By 9 months of age adenomas of the liver appeared, progressing to HCC over the ensuing 6-month period. By 15-17 months of age, 87% of male and 69% of female animals had either adenomatous nodules or HCCs. By 17 months of age, 31% of male and female animals had disease that had progressed to HCC. These animals represent a unique and significant new model for the study of human HCC. This study demonstrates that overexpression of cyclin D1 is sufficient to initiate hepatocellular carcinogenesis.
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PMID:Hepatocellular carcinoma results from chronic cyclin D1 overexpression in transgenic mice. 1145 81

Mutations in the glycogen synthase kinase 3beta (GSK3beta) phosphorylation sites of the beta-catenin gene exon 3 are found in 20-30% of human primary hepatocellular carcinoma (HCC), whereas mutations in the APC or AXIN genes are found in other HCC populations. These data strongly suggest that the Wnt signaling pathway is involved in hepatocarcinogenesis. To determine the role of beta-catenin in intestinal tumorigenesis, we earlier constructed a mutant mouse strain Catnb(lox(ex3)), in which exon 3 of the beta-catenin gene was sandwiched by loxP sequences. By genetic crosses of these mice with the Fabpl-cre transgenic mice that express the cre gene controlled by the fatty acid binding protein gene promoter, we introduced the beta-catenin stabilizing mutation into the small intestine and liver. Although numerous polyps were formed in the small intestine, we did not find any neoplastic (i.e., dysplastic) foci in the liver, and the mice died in 5 weeks after birth because of acute liver damage accompanying mitochondrial swelling. When a recombinant adenovirus that expresses the cre gene from a human cytomegalovirus early gene promoter was constructed and inoculated at a high multiplicity (10(9) plaque-forming units/mouse), the Catnb(lox(ex3)) mice showed marked hepatomegaly, with similar mitochondrial swelling in the hepatocytes, and died within 3 weeks after infection. On the other hand, when inoculated at lower multiplicities of infection (10(7) and 10(8) plaque-forming units/mouse, respectively), the Catnb(lox(ex3)) mice survived >6 months without any neoplastic foci in the liver, although the nuclear localization of beta-catenin was found in some hepatocytes even after 6 months. These results suggest that, in contrast to intestinal polyposis, the Wnt pathway activation by stabilized beta-catenin is not sufficient for hepatocarcinogenesis, but additional mutations or epigenetic changes may be required.
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PMID:Lack of tumorigenesis in the mouse liver after adenovirus-mediated expression of a dominant stable mutant of beta-catenin. 1192 13

Perfluorooctanesulfonate (PFOS) is a persistent organic pollutant with significant bioaccumulation potential in liver tissues. Exposure to PFOS could cause increase of liver weight, induce adenomas of the liver, and cause hepatomegaly. Alternatives of PFOS might be designed and synthesized that have significantly lower liver bioaccumulation. In this study, we conducted animal exposure experiments to investigate tissue accumulations of 14 per- and polyfluoroalkyl substances. Correlation analysis demonstrated that accumulation of the compounds in rat liver had strong correlations with their binding affinities of liver fatty acid binding protein (LFABP). Thus, we combined a quantitative structure-activity relationship model with molecular dynamics (MD) simulations to develop computational models to predict the LFABP binding affinities of two newly synthesized alternatives, perfluorodecalin-2-sulfonic acid and N-diperfluorobutanoic acid. The binding characteristics of the PFOS alternatives for LFABP were elaborated to explore how the different structural modifications of molecules influenced the underlying binding mechanisms. Subsequent animal experiments demonstrated that the binding free energy calculations based on the MD simulations provided a good indicator to reflect the relative degree of liver accumulation of the PFOS alternatives in the same exposure doses and durations. Our findings from the combination of experimental exposure and computational model can provide helpful information to design potential alternatives of PFOS with weak LFABP binding capability and low liver accumulation.
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PMID:Screening of Potential PFOS Alternatives To Decrease Liver Bioaccumulation: Experimental and Computational Approaches. 3073 64