Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0345904 (liver cancer)
 15,188 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

For colorectal carcinomas, the rate of tumor development is proportional to the fourth to sixth power of elapsed time, suggesting that four to six independent events are necessary. Although similar calculations have not been made for HBV-associated HCCs, it is likely that this is also the case for HCCs, since individuals with persistent HBV infection do not usually develop HCC until they are 45 or greater years old. As evidence for specific genetic and epigenetic changes in HCCs accumulate, the important players in multistep hepatocarcinogenesis are becoming clearer. However, even though Myc family oncogenes are clearly implicated in woodchuck HCC, similar integrations have not been found in human HCCs. Therefore, although rodent and human systems have many similarities, we must realize that important differences may also exist. Regarding tumor suppressor genes, the evidence for p53 alterations in HCC is strong. A growing body of evidence suggests further that alterations in the retinoblastoma gene and one or more tumor suppressor genes on chromosome 11 are also involved in HCC. HBV integrations may certainly play a role in the generation of chromosome aberrations leading to loss of tumor suppressor alleles, since chromosomes 11 and 17 are the most common integration sites. Finally, the role of X proteins as participants in malignant transformation has been demonstrated for certain immortalized, nontransformed hepatocytes. Altered autocrine mechanisms of cell growth control, possibly involving IGF-II, are clearly implicated in HCC. Paracrine mechanisms for the control of hepatocyte growth and differentiated functions may also be altered as a result of the synthesis and secretion of a complex array of interleukins, HGF, and basic and acidic FGFs by cells in the inflammatory and cirrhotic lesions of precancerous livers. Whether the order of molecular changes in the hepatocyte is important for malignant progression is presently not clear. What is clear, however, is that hepatocarcinogenesis involves alterations in the concerted action of protooncogenes, growth factor, and tumor suppressor genes. How these factors interact will provide a more complete understanding of the mechanism or mechanisms of hepatic oncogenesis.
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PMID:Cellular and molecular mechanisms of hepatocarcinogenesis. 143 79

Insulin-like growth factor (IGF) I and IGF-II were measured by radioimmunoassay in the sera of seven patients with acromegaly, 36 normal control subjects, 15 patients with chronic hepatitis, 15 patients with cirrhosis, 25 patients with hepatocellular carcinomas (HCCs) who did not have hypoglycemia, 20 patients with HCCs who did have hypoglycemia, and 10 patients with metastatic liver tumors. Both IGF-I and IGF-II levels decreased as liver disease progressed from the normal control stage to chronic hepatitis and cirrhosis, and both levels reflected the severity of liver disease. Patients with HCCs who had hypoglycemia had relatively higher IGF-II levels in their sera in comparison with those who did not have hypoglycemia (272 +/- 167.5 ng/ml vs 110.4 +/- 85.9 ng/ml [mean +/- SD], p less than 0.0005), despite the fact that those with hypoglycemia had more advanced liver cancer and had lower IGF-I levels in sera (16.7 +/- 14.1 ng/ml vs 46.8 +/- 47.9 ng/ml, p less than 0.002). It is possible that a labile IGF-II material is produced by the cancer cells of patients with hypoglycemia. This factor is reactive to the IGF-II receptor and partially cross-reacts with an antibody to IGF-II; it accounted for the mildly elevated levels of serum IGF-II. Hypoglycemia may be an integral effect of relatively elevated IGF-II like material and an advanced liver cancer. Also, higher serum alpha-fetoprotein (AFP) levels were more frequently found in patients with hypoglycemia who had relatively elevated IGF-II levels and short survivals.
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PMID:Radioimmunoassay of serum IGF-I and IGF-II in patients with chronic liver diseases and hepatocellular carcinoma with or without hypoglycemia. 246 May 70

Insulin-like growth factor I (IGF-I) and IGF-II are peptides that presumably are required for normal fetal and postpubertal growth. The production of IGFs is developmentally regulated and the liver appears to be a major site of production. By analysing mRNA levels for IGF-I and IGF-II in the rat liver we have attempted to further study the expression of these growth factors during development and regeneration as well as during the course of hepatic carcinogenesis. Fetal livers are characterized by a high level of IGF-II mRNA and a low level of IGF-I mRNA, while in adult livers the opposite situations occur, i.e. a high level of IGF-I mRNA and a non-measurable level of IGF-II mRNA. During the course of experimentally induced hepatic cancer, IGF-I mRNA was consistently reduced and in a majority of cancers analysed (6/9) IGF-II mRNA was increased, i.e. a fetal type of IGF expression can be switched on in some experimentally induced hepatocellular carcinomas. The onset of IGF-II production during hepatic carcinogenesis appears to be a late phenomenon since liver nodules, preceding the development of hepatocellular cancer, were found not to contain IGF-II mRNA. Furthermore, during hepatic regeneration following partial hepatectomy no marked change in IGF-I or IGF-II mRNA levels was noted. The above results suggest that the fetal growth factor IGF-II could have a role in hepatic cancer.
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PMID:Expression of insulin-like growth factor I (IGF-I) and IGF-II mRNA during hepatic development, proliferation and carcinogenesis in the rat. 333 3

Hepatocellular carcinoma (HCC) is a common malignancy, but treatment outcomes have generally remained poor. Specific factors important for the pathogenesis of HCC are incompletely understood. Insulin-like growth factors (IGFs) are potent autocrine and paracrine mitogens for liver cancer cell proliferation, and their bioactivity is reduced by IGF-binding protein 3 (IGFBP-3). In the present study, we report that IGFBP-3 protein levels were either undetectable (28.5%) or low (71.5%) in human HCC samples examined compared with matched non-neoplastic liver tissue by Western blotting. IGFBP-3 was localized to nontumor liver cells by immunohistochemistry with greater immunointensity than neoplastic liver cells. Levels of type I receptor (IGF-IR) were found to be low in approximately 39% of human HCC samples examined compared with matched nontumor tissues. IGF-II was overexpressed in 32%, whereas IGF-I expression was decreased in 100% of HCC samples. In vitro studies revealed that IGF-I and IGF-II induced HepG2 cell proliferation in a dose-dependent manner. Treatment of HepG2 cells with either human recombinant IGFBP-3 (hrIGFBP-3) or IGF-II antibody led to a significant reduction in cell proliferation. Cotreating these cells with hrIGFBP-3 significantly attenuated the mitogenic activity of IGF-I. IGF-I-induced phosphorylation of IGF-IR beta subunit, IRS-1, mitogen-activated protein kinase, Elk-1, and Akt-1 as well as phosphatidylinositol 3'-kinase activity was significantly attenuated when hepG2 cells were pretreated with hrIGFBP-3. Our data indicate that loss of autocrine/paracrine IGFBP-3 loops may lead to HCC tumor growth and suggest that modulating production of the IGFs, IGFBP-3, and IGF-IR may represent a novel approach in the treatment of HCC.
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PMID:A possible role for insulin-like growth factor-binding protein-3 autocrine/paracrine loops in controlling hepatocellular carcinoma cell proliferation. 1195 12

Insulin-like growth factor binding protein-1 (IGFBP-1) is synthesized in the liver and regulates the mitogenic effects of the insulin-like growth factors (IGFs). The evidence that IGFBP-1 plays a role in hepatocarcinogenesis, however, is equivocal. We have, therefore, investigated the development of preneoplastic hepatic lesions in transgenic mice in which the human IGFBP-1 gene is under the control of the mouse metallothionein promoter. The lesions were induced by treating 15-d-old male mice with a single intraperitoneal injection of 5 mg/kg diethylnitrosamine (DENA). Lesions were scored when the mice were 28 wk of age. Quantitative microscopy of liver sections revealed that significantly fewer transgenic mice treated with zinc to activate the transgene had focal lesions compared to either transgenic mice not treated with zinc or wild-type mice treated with zinc (36.4% versus 85.7% and 83.3%, respectively, P < 0.05 in each case). Zinc-treated transgenic mice also had significantly fewer lesions per liver (11.5 +/- 5.0 versus 74.7 +/- 18.4 and 59.4 +/- 15.6, respectively, P < 0.01 in each case) and a smaller percentage of liver volume occupied by lesions (0.2 +/- 0.1 versus 1.4 +/- 0.3 and 1.1 +/- 0.4 respectively, P < 0.05 in each case). Immunohistochemical staining showed that both IGF-I and IGF-II were overexpressed in most of the lesions. These results show that expression of the IGFBP-1 transgene leads to a marked inhibition of hepatic preneoplasia, possibly by decreasing the mitogenic activity of IGF-I and/or IGF-II. This study adds new evidence to the notion that the IGF axis plays an important role in liver cancer development.
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PMID:Insulin-like growth factor binding protein-1 over-expression in transgenic mice inhibits hepatic preneoplasia. 1261 36

Insulin-like growth factors (IGFs) are mitogens for numerous types of cells including cancer cells. The aim of this work was to analyze some of the components of the IGF system to assess which could be potential clinical biomarkers for monitoring patients diagnosed with liver cancer. Compared to healthy persons, patients with liver cancer had a lower concentration of IGF-I and a higher concentration of IGFBP-1, whereas the concentrations of IGF-II and IGFBP-3 remained unchanged. The IGF-I:IGFBP-3 ratio decreased in patients with cancer, while the IGF-II:IGFBP-1 ratio was not altered. Patients with primary carcinoma and those scheduled for surgery had lower IGF-I and higher IGF-II and IGFBP-1 concentrations than patients with secondary carcinoma and those not eligible for surgery. It may be postulated that a liver with primary cancer is induced to increase IGF-II and IGFBP-1 synthesis more than a liver involved in metastatic response. Similarly, in patients eligible for liver surgery an increase in IGF-II may reflect a gradual change in the concentration associated with a different stage of disease. As increased synthesis of certain IGFBPs is necessary to compensate decreased production of the others or increased IGF production, determination of serum IGF-II, IGFBP-1 and their ratio may aid in estimating the compensatory capacity of the liver affected by cancer.
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PMID:Association of elevated IGFBP-1 with increased IGF-II concentration in patients with carcinoma of the liver. 1919 70