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)

Liver tumors were induced in male C3H mice by a single injection of N-nitrosodiethylamine and characterized with respect to the presence of base substitutions in the hot-spot position at codon 61 of the Ha-ras proto-oncogene. An increase in Ha-ras mutation prevalence was found with time after induction of tumors, suggesting that the activated ras gene provides a selective growth advantage. However, no significant differences in 5-bromodeoxyuridine labeling indices were evident between ras mutated and ras wild-type tumors, demonstrating that cell division rates in the two tumor populations were very similar. Apoptotic indices were determined by counting eosinophilic apoptotic bodies. The frequency of occurrence of apoptotic bodies was found to be approximately five times lower in tumors with Ha-ras mutations when compared with tumors not showing the mutation. This demonstrates that the activated p21(Ras) protein has anti-apoptotic activity in transformed mouse hepatocytes in vivo and suggests that the preferential outgrowth of Ha-ras-mutated hepatoma cells is mediated by suppression of apoptosis rather than by stimulation of cell division.
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PMID:Suppression of apoptosis in C3H mouse liver tumors by activated Ha-ras oncogene. 1065 52

Long-Evans Cinnamon (LEC) rats develop severe hepatitis and subsequent hepatoma with excess accumulation of copper in the liver with increasing age. Lipids extracted from the LEC rat liver membrane were studied using FT-IR spectroscopy and an HPLC technique at the stages of pre-hepatitis and hepatitis, i.e. at 10 and 16 weeks of age, respectively. The 10-week-old rats exhibited an IR spectrum characteristic of a phosphatidylcholine and phosphatidylethanolamine mixture with a ratio of 2:1. The 16-week-old rats developed new absorption bands at 1161 and 1070 cm(-1), which were assigned to the spectra of triglyceride, neutral lipid, and diacylglycerol, an endogenous activator of protein kinase C, respectively. The diacylglycerol was estimated to amount to ca. 10% (w/w) of phospholipid extract by comparing the spectrum with those of model compounds. This was confirmed using an HPLC assay. Previously, we found that a serum response factor is activated by copper in the LEC rat liver, and suggested that it must mediate proto-oncogene c-fos induction. The results obtained here suggest that accumulation of diacylglycerol plays an important role in development of hepatoma in LEC rats by mediating proto-oncogene c-fos induction.
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PMID:Accumulation of diacylglycerol in the liver membrane of the Long-Evans Cinnamon (LEC) rat with hepatitis: FT-IR spectroscopic and HPLC detection. 1076 18

Growth hormone (GH), given therapeutically in many human diseases, is able to modulate the maturation and function of many cells of immune system. The present study demonstrates the effect of human recombinant GH on the production of acute phase proteins (APP) as well as on the gene expression of junB proto-oncogene on human hepatoma cell line, HepG2. When applied alone GH resulted in an increase in the transcription of junB proto-oncogene within 30 min. The production of alpha2-macroglobulin, haptoglobin and fibrinogen was also enhanced by rhGH treatment. However, both IL-6-stimulated junB gene expression (junB mRNA) and biosynthesis of type II APP (alpha2-macroglobulin, fibrinogen, haptoglobin) were strongly inhibited by the GH. The results indicate that GH has a modulatory role in regulating inflammation both in the absence and presence of IL-6. These findings call for further in vivo studies to determine the potential anti-inflammatory actions of GH therapy.
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PMID:Interleukin-6-induced production of type II acute phase proteins and expression of junB gene are downregulated by human recombinant growth hormone in vitro. 1077 70

To discriminate among the chromosomal abnormalities associated with the etiology of hepatocellular carcinoma (HCC), we performed a comparative genomic hybridization (CGH) analysis on 34 HCCs resected on non-cirrhotic livers from patients serologically negative for both hepatitis B (HBV) and C (HCV) viruses. The results were compared to those of a previous analysis of 50 HCCs selected on the basis of their positivity for HBV infection. The majority of the abnormalities found in the HBV positive cases (losses of chromosome arms 1p, 8p, 6q, 13q and 14q and gains of 1q, 8q, 6p and 17q) were similarly detected in the virus negative specimens. In contrast, a significant decrease (40% on average) was observed for losses at 4q, 16q and 17p in non-viral HCC samples, suggesting that these abnormalities are tightly associated with HBV infection. Thus, in addition to a common pathway towards malignancy, a subset of alterations may preferentially contribute to virus-induced carcinogenesis. In a parallel CGH study of 10 fibrolamellar carcinomas, a rare subtype of HCC, we found in six out of the seven informative cases, gains of chromosome arm 1q. This region, which is also preferentially amplified in non fibrolamellar tumors (58%), may contain an essential proto-oncogene commonly implicated in liver carcinogenesis.
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PMID:Distinct chromosomal abnormality pattern in primary liver cancer of non-B, non-C patients. 1094 27

Exposure of rat hepatoma cells to a low concentration of Coptidis Rhizoma reduces cell viability and probably induces apoptotic cell death. However, Coptidis Rhizoma treatment increased the expression of a putative c-myc-responsive gene rcl and could increase the activity of a transcription factor in inhibiting the growth of cancer cells. This increase was accompanied by an increment in the expression of mRNA for c-myc-responsive gene. The expression was analysed by PCR and confirmed by Northern blot analysis. The rcl expression level increases with the Coptidis Rhizoma concentration, and in the time-course study. The results suggest the expression of rcl is important to the fate of cell growth, since overexpression of the c-myc proto-oncogene cell proliferation, differentiation, and apoptosis can be regulated by the treatment of Coptidis rhizoma. Additionally, difference between overexpression of c-myc-responsive gene in the control suggested that this protein was responsible for the inhibitory effect of a transcriptional factor on cell growth. The results support the notion of rcl as an important antiapoptotic protein mediating sensitivity to Coptidis Rhizoma induction in cancer cells. rcl may play an important role during cellular proliferation and c-myc-mediated transformation.
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PMID:Induction of rcl, a novel growth-related gene by coptidis rhizoma in rat H4IIE cells. 1199 Dec 56

The human c-erb B2 proto-oncogene (Her2/ ) encodes a 185-kD transmembrane putative growth factor receptor of the tyrosine kinase family. Overexpression or amplification of this oncoprotein/oncogene has been established in breast, ovarian, salivary gland, and gastric carcinomas and has been implicated in other neoplasms. Recently, overexpression of c-erb B2 has been demonstrated in hepatocellular carcinoma using enzyme-linked immunosorbent assay. Patients with hepatocellular carcinoma have a poor prognosis, and overexpression of c-erb B2 may have prognostic and treatment implications. The authors evaluated the expression and amplification of c-erb B2 in hepatic neoplasms utilizing routine immunohistochemistry and fluorescence in situ hybridization. Formalin-fixed paraffin-embedded tissue sections from 27 hepatocellular carcinomas and 7 hepatocellular adenomas were immunostained with anti-c-erb B2 utilizing a modified avidin-biotin technique following heat induced antigen retrieval. Ten sections from hepatocellular carcinomas were subjected to fluorescence in situ hybridization assay. Positive and negative controls stained appropriately. Slides were evaluated independently by two pathologists. None of the hepatocellular carcinomas or hepatocellular adenomas was immunoreactive with anti-c-erb B2. Adjacent cirrhotic liver parenchyma, present in 11 cases, was also uniformly negative. None of hepatocellular carcinomas showed any evidence of c-erb B2 amplification by fluorescence in situ hybridization. Immunoreactivity for c-erb B2 was not demonstrated in hepatocellular adenomas, cirrhotic livers, or hepatocellular carcinomas using routine immunohistochemical methods. C-erb B2 amplification was not demonstrated in hepatocellular carcinomas. Neither overexpression nor amplification of c-erb B2 (Her2/ ) can be regarded as a useful prognostic factor in hepatocellular carcinoma.
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PMID:C-erb B2 (Her2/neu) is neither overexpressed nor amplified in hepatic neoplasms. 1237 50

Hepatocyte growth factor-scatter factor (HGF-SF) is a potent hepatic mitogen yet inhibits hepatocellular carcinoma (HCC) cell growth in vitro. Insulin-like growth factor I (IGF-I) is a pleiotropic growth factor shown to be important in cell growth and differentiation in other tumors. We hypothesized that IGF-I may play a role in regulating HGF-SF activity and HCC progression. Using an in vivo model of HCC, we showed elevated IGF-I messenger RNA (mRNA) expression in normal liver from tumor-burdened animals in the absence of changes in circulating IGF-I levels. Analysis of IGF-I receptor (IGF-IR) and HGF-SF (c-met) receptor expression showed significantly higher expression of both receptors in normal liver compared with an HCC specimen. Using cultured HCC cells from this model, we next showed that treatment with IGF-I led to significant increases in mitogen-activated protein kinase (MAPK) activity. Furthermore, we observed significant time-dependent increases in the expression of the c-fos and c-jun proto-oncogenes after addition of IGF-I (n = 5 per group, P <.05). Despite activation of a MAPK pathway and increased proto-oncogene expression, IGF-I failed to significantly affect cell mitogenesis. In contrast, HGF significantly inhibited cell mitogenesis in HCC lines (68.4% +/- 9.4% vs. control, n = 4, P <.05). Pretreatment of HCC cells with IGF-I (60 minutes) led to significant HGF-SF stimulation of total cell mitogenesis dependent on both IGF-I and HGF-SF dose (194% +/- 8% increase vs. control, n = 4, P <.05). In conclusion, tumor burden is important in altering intrahepatic growth factor synthesis. Signal cooperation between multiple cytokine pathways is an important factor in the progression of HCC.
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PMID:Insulin-like growth factor I is a comitogen for hepatocyte growth factor in a rat model of hepatocellular carcinoma. 1239 18

Hepatocyte growth factor (HGF) signaling via its receptor, the proto-oncogene Met, alters cell proliferation and motility and has been associated with tumor metastasis. HGF treatment of HepG2 human hepatocellular carcinoma cells induces cell migration concomitant with increased levels of the p27(kip1) cyclin-cdk inhibitor. HGF signaling resulted in nuclear export of endogenous p27 to the cytoplasm, via Ser-10 phosphorylation, where it colocalized with F-actin. Introduction of transducible p27 protein (TATp27) was sufficient for actin cytoskeletal rearrangement and migration of HepG2 cells. TATp27 mutational analysis identified a novel p27 C-terminal domain required for cell migration, distinct from the N-terminal cyclin-cyclin-dependent kinase (cdk) binding domain. Loss or disruption of the p27 C-terminal domain abolished both actin rearrangement and cell migration. The cell-scattering activity of p27 occurred independently of its cell cycle arrest functions and required cytoplasmic localization of p27 via Ser-10 phosphorylation. Furthermore, Rac GTPase was necessary for p27-dependent migration but alone was insufficient for HepG2 cell migration. These results predicted a migration defect in p27-deficient cells. Indeed, p27-deficient primary fibroblasts failed to migrate, and reconstitution with TATp27 rescued the motility defect. These observations define a novel role for p27 in cell motility that is independent of its function in cell cycle inhibition.
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PMID:Novel p27(kip1) C-terminal scatter domain mediates Rac-dependent cell migration independent of cell cycle arrest functions. 1248 75

Apoptin, a protein encoded by an avian virus, induces apoptosis in various cultured human tumorigenic and/ or transformed cell lines, e.g. derived from breast and lung tumor, leukemia, lymphoma, osteosarcoma melanoma, cholangiocarcinoma, and hepatoma. In such cells, Apoptin induces p53-independent apoptosis, and the proto-oncogene Bcl-2 can accelerate this effect. The latter is surprising for, in general, Bcl-2 is known to inhibit e.g., p53-induced apoptosis. On the other hand, in normal non-transformed human cells, Apoptin is unable to induce apoptosis, even when Bcl-2 is over-expressed. In animal models Apoptin-induced apoptosis appears to be a safe and efficient anti-tumor agent. These data, in continuation with the observations that Apoptin is specifically stimulated by Bcl-2 in tumor cells, does not need p53, and is not inhibited by Bcr-Abl in these cells, imply that Apoptin is a potential anti-tumor therapy.
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PMID:Apoptin-induced apoptosis: a review. 1463 34

The proto-oncogene c-myc encodes a transcription factor that plays a pivotal role in cell proliferation, differentiation, and apoptosis. The signaling mechanism of c-Myc-induced apoptosis was investigated on the human hepatoma Huh7 cells under growth factor-deprived conditions. The apoptotic process did not involve p53. Rather it was dependent on the expression of c-Fos. Activation of caspases 3 and 9 and down-regulation of Bcl2 were observed in the apoptotic process, indicating it to be a mitochondria-dependent event. An increase in the p38 mitogen-activated protein kinase that was mediated by a Rac1-dependent and cdc42-independent pathway eventually leading to up-regulation of c-Fos activity was also observed. Deletion analysis of the promoter region of the c-fos gene indicated that the ATF2-responsive element conferred the Myc-induced expression of c-Fos. Co-expression of the dominant-negative mutants of c-Fos, p38, and Rac1 blocked the Myc-mediated apoptosis. SB20358, a chemical inhibitor of p38 pathway, also specifically blocked the apoptotic signaling by c-Myc. Furthermore, co-expression of the hepatitis B virus X protein (HBx) along with Myc abrogated the apoptotic signals. The HBx expression was associated with an increase in the levels of phosphorylated AKT and down-regulation of c-Fos by Myc. Thus, c-Fos seems be a new mediator of c-Myc-induced apoptosis.
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PMID:c-Fos is a mediator of the c-myc-induced apoptotic signaling in serum-deprived hepatoma cells via the p38 mitogen-activated protein kinase pathway. 1507 69


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