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

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.
 ...
PMID:Lack of tumorigenesis in the mouse liver after adenovirus-mediated expression of a dominant stable mutant of beta-catenin. 1192 13

Dysregulated Wnt signaling is seen in approximately 30% of hepatocellular carcinomas; thus, finding pathways downstream of the activation of Wnt signaling is key. Here, using cre-lox technology, we deleted the Apc gene in the adult mouse liver and observed a rapid increase in nuclear beta-catenin and c-Myc, which is associated with an induction of proliferation that led to hepatomegaly within 4 days of gene deletion. To investigate the downstream pathways responsible for these phenotypes, we analyzed the impact of inactivating APC in the context of deficiency of the potentially key effectors beta-catenin and c-Myc. beta-catenin loss rescues both the proliferation and hepatomegaly phenotypes after APC loss. However, c-Myc deletion, which rescues the phenotypes of APC loss in the intestine, had no effect on the phenotypes of APC loss in the liver. The consequences of the deregulation of the Wnt pathway within the liver are therefore strikingly different from those observed within the intestine, with the vast majority of Wnt targets being beta-catenin-dependent but c-Myc-independent in the liver.
 ...
PMID:B-catenin deficiency, but not Myc deletion, suppresses the immediate phenotypes of APC loss in the liver. 2571 28

Thymic carcinoma is an overall rare tumour with variable clinical manifestations. Right ventricular failure remains an uncommon occurrence and has not been reported in literature so far. A 40-year-old lady presented with the complaints of progressively worsening retrosternal chest pain, shortness of breath, easy fatigability and cough since 1 year. Computed tomography scan of the thorax revealed a mass measuring 12 x 10 cm in the anterior mediastinum. This mass appeared to be adherent to both lungs and pericardium and was impinging on the right atrium and right ventricle. It appeared to be infiltrating the ascending aorta, pulmonary arteries and superior vena cava. Ultrasound of the abdomen showed hepatomegaly and moderate ascites. Echocardiography showed evidence of right ventricular dysfunction as well as elevated right ventricular systolic pressures secondary to extrinsic compression. Percutaneous biopsy of the thymus was performed showing a malignant thymoma. Radical thymectomy with resection of pericardium was planned. Intra-operatively, the tumour was separated from the right and left lungs, pulmonary artery and aortic arch. Morphologically, immunochemically and clinically, the features were consistent with those seen in Masoka stage III thymic carcinoma. She also received six cycles of chemotherapy (PAC regimen) including cisplatin (50 mg/m2), doxorubicin (50 mg/m2) and cyclophosphamide (500 mg/m2). Radiation therapy in the adjuvant setting was planned but the patient was lost to follow-up after 4 months. Although right ventricular failure is a very rare presentation of thymic carcinoma, clinicians should be aware of this presentation to appreciate the complete clinical spectrum of presentation of this neoplasm.
 ...
PMID:Large thymic carcinoma presenting with right ventricular failure: a case report. 2193 89