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)

Previous reports indicate that human hepatocytes do not express class I and class II MHC antigens. Our analyses on 10 human hepatocellular carcinoma (HCC) cell lines by immunofluorescence tests and RIA, demonstrate that all the human HCC cell lines tested express class I MHC antigens and among them, three poorly differentiated human HCC cell lines also express class II MHC antigens. Results of immunoprecipitation and/or Western blotting experiments indicate similarity in the chemical nature of both the class I and class II MHC antigens expressed by the human HCC cell lines and by a human B lymphoblastoid cell line Raji. Furthermore, a new variant form of class I antigen was detected in some of these HCC cell lines. Immunohistochemical studies of HCC tissues using the peroxidase-antiperoxidase staining method indicated that class I and class II antigens were detectable in 7 out of 11 and 3 out of 11 HCC tissues from patients, respectively. The availability of MHC class I antigen-positive cultured HCC cell lines, including the poorly differentiated lines that also express MHC class II antigen, has provided us with interesting models to study the relationship between expression of MHC antigen and transformation and differentiation of human hepatocytes. These studies will also allow us some insight into the role of MHC class I and class II antigen in the immunosensitivity and immunogenicity of HCC cells to the host-immune response.
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PMID:Expression of class I and class II major histocompatibility antigens on human hepatocellular carcinoma. 253 98

Monoclonal antibodies were used in one step sandwich enzyme immunoassay (one step sandwich EIA) for human serum immunoreactive type IV collagen. The one step sandwich EIA using either polystyrene ball or microplate was characterized by carrying out two immunoreactions simultaneously, type IV collagen reacting with both a monoclonal antibody as a solid phase and a horseradish peroxidase-labeled monoclonal antibody (Fab') against human type IV collagen as a conjugate. Sensitivity of one step sandwich EIA system by using either polystyrene ball or microplate was 0.22 ng per tube or 0.04 ng per well for type IV collagen, and linearity was obtained between 0.22-40 ng/tube or 0.04-20 ng per well, respectively. Both methods gave reproducible quantitative analysis of immunoreactive type IV collagen levels in the sera of patients with hepatocellular carcinoma and patients with liver cirrhosis, which were apparently higher than the levels in the sera of healthy subjects. Protein immunoblotting shows that the immunoreactive type IV collagen trapped in our present one step sandwich EIA system was not the 7-S and NC1 domains of type IV collagen.
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PMID:One step sandwich enzyme immunoassay for human type IV collagen using monoclonal antibodies. 254 37

Aberrant proto-oncogene expression has been implicated in hepatic cell proliferation, transformation and carcinogenesis using a rat model. To investigate the role of ras p21 product expression in human hepatocellular carcinoma (HCC), we have localized ras p21 in formalin fixed, paraffin-embedded normal and abnormal livers utilizing the avidin-biotin peroxidase method and a monoclonal antibody to ras-gene product p21. A semi-quantitative estimate of p21 expression was performed by serial dilutions of primary antibody. While low dilutions of anti-p21 stained normal hepatocytes, higher dilutions failed to react with normal hepatocytes and these dilutions were used for assessment of p21 enhancement. Increased p21 expression of ras oncogene in HCC occurs in fibrolamellar carcinomas and other better differentiated HCC. Tumor dedifferentiation is associated with an attenuation of p21 expression. Liver adjacent to HCC exhibits p21 enhancement, in contrast to liver surrounding metastatic carcinoma, suggesting increased p21 expression in HCC induction.
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PMID:ras oncogene p21 expression in hepatocellular carcinoma. 255 Jun

Ricinus communis agglutinin I(RCAI) receptors in 25 cases of hepatocellular carcinoma and 6 cases of intrahepatic cholangiocellular carcinoma were immunohistochemically localized by avidin-biotin-peroxidase complex (ABC) method. In the meantime, RCAI receptors in normal and cirrhotic liver tissues were also observed as controls. The results showed that there were many irregularly distributed RCAI receptors in HCC in forms of dispersed dots, even or localized lumpy stainings. The receptors in most intrahepatic cholangiocellular carcinomas were distributed in a polar form. However, the distribution of RCAI receptors in hepatocytes of normal, cirrhotic and precancerous liver tissues was band-like. It is suggested that the distribution of RCAI receptors in the cells might be helpful to the diagnosis of hepatoma and to the differentiation of benign from malignant hyperplasia.
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PMID:[A study of ricinus communis agglutinin I receptors in liver cancer tissues]. 255 38

Cellular copper metabolism and the mechanism of resistance to copper toxicity were investigated using a wild type hepatoma cell line (HAC) and a copper-resistant cell line (HAC600) that accumulates copper and has a highly elevated level of metallothionein (MT). Of the enzymes involved in reactive oxygen metabolism, only glutathionine peroxidase was elevated (3-4-fold) in resistant cells, suggestive of an increase in the cellular flux of hydrogen peroxide. A majority of the cytoplasmic copper (greater than 60%) was isolated from both cell lines as a GSH complex. Kinetic studies of 67Cu uptake showed that GSH bound 67Cu before the metal was complexed by MT. Depletion of cellular GSH with buthionine sulfoximine inhibited the incorporation of 67Cu into MT by greater than 50%. These results support a model of copper metabolism in which the metal is complexed by GSH soon after entering the cell. The complexed metal is then transferred to MT where it is stored. This study also indicates that resistance to metal toxicity in copper-resistant hepatoma cells is due to increases in both cellular GSH and MT. Furthermore, it is suggested that elevated levels of GSH peroxidase allows cells to more efficiently accommodate an increased cellular hydrogen peroxide flux that may occur as a consequence of elevated levels of cytoplasmic copper.
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PMID:The role of glutathione in copper metabolism and toxicity. 256 91

A significant increase in the molecular weights of lamin A and more so of lamin C was observed when isolated Novikoff hepatoma chromatin was incubated in the presence of Ca2+. This increase did not occur to any significant degree in similar preparations of normal rat liver nuclei. Although detectable in Coomassie Brilliant Blue stained gels, this increase to a higher molecular weight (by approximately 2000 Mr) was much more visible when the electrophoretically separated lamins were transferred to nitrocellulose sheets and stained (using peroxidase-antiperoxidase) with polyclonal antiserum to the three major lamin proteins. This modification could also be induced when whole Novikoff hepatoma cell lysates were incubated in the presence of calcium. Again, this change did not occur in normal rat liver cells treated in the same manner. Further analysis has provided evidence that this modification is most likely mediated by the transaminating activity of an intrinsic nuclear transglutaminase forming a cross-link between the affected lamins and an unknown low molecular weight (approximately equal to 2000 Mr) moiety.
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PMID:Enzymatic modification of Novikoff hepatoma lamins A and C. 257 66

Detection of RNA transcripts within individual cells by in situ hybridization provides a powerful means for identifying specific cell types actively transcribing specific genes. We have applied this technique in order to analyze expression of the alpha-fetoprotein and albumin genes in a human hepatoma cell line, HuH-7. Using either 3H- or 35S-labeled human alpha-fetoprotein complementary DNA clone as a probe, we found that essentially all HuH-7 cells contained alpha-fetoprotein mRNA, although in various amounts. This correlated well with the presence of alpha-fetoprotein in all cells as detected by the peroxidase-antiperoxidase immunoenzyme method. The intracellular concentration of albumin, on the other hand, was below the level of detection by the peroxidase-antiperoxidase method. Consistent with this observation, we could not detect albumin mRNA with 3H-labeled albumin complementary DNA probes. However, the use of 35S-labeled probes having higher specific activities and higher efficiency of grain development resulted in the detection of albumin mRNA in a small percentage of HuH-7 cells. A variety of parameters involved in the in situ hybridization technique was examined to establish conditions suitable for demonstrating the presence of high- and low-copy numbers of mRNA in various cell and tissue preparations.
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PMID:Detection of messenger RNAs of alpha-fetoprotein and albumin in a human hepatoma cell line by in situ hybridization. 257 34

The metabolism of chemical carcinogens was investigated in liver preparations from 28 captive woodchucks (Marmota monax). Of these, 23 were naturally infected with the woodchuck hepatitis virus (WHV), and eight also had primary hepatocellular carcinoma (PHC). Twenty-nine parameters were investigated in liver subcellular fractions, including cross-reactivity with HBsAg, and biochemical parameters, such as gamma-glutamyl transpeptidase, cytochrome P-450 and microsomal monooxygenases (aryl hydrocarbon hydroxylase, ethoxycoumarin and ethoxyresorufin deethylases, aminopyrine and dimethylnitrosamine demethylases, and testosterone 7 alpha-, 16 alpha- and 6 beta-hydroxylases), uridine 5'-diphosphoglucuronosyl transferase, GSH and related enzymes (peroxidase, reductase and S-transferase), as well as other cytosolic enzyme activities (glucose 6-phosphate and 6-phosphogluconate dehydrogenases, NADPH- and NADH-dependent diaphorases, and DT diaphorase). In addition, liver preparations were used in order to quantify the metabolic activation into bacterial mutagens of five procarcinogens (aflatoxin B1, the pyrolysis products Trp-P-2 and MeIQ, 2-aminofluorene and dimethylnitrosamine) and the decrease of potency of three direct-acting mutagens (sodium dichromate, ICR 191 and 4-nitroquinoline 1-oxide). WHV infection produced a significant stimulation of carcinogen metabolism, as shown by the simultaneous change in detoxification parameters (GSH depletion) and activation indices (enhancement of microsomal monooxygenases and of procarcinogen activation into mutagenic metabolites). There were no significant differences between WHV-positive samples from animals without PHC and the noncancerous tissue of PHC-bearing animals, whereas a decrease of both activation and detoxification indices was recorded in the tumorous tissue. There was a considerable interindividual variability among WHV carriers, which was tentatively ascribed to genetic factors. Pregnancy was the only known factor influencing the results in WHV carriers. However, even by excluding pregnant animals, the effects on carcinogen metabolism produced by WHV infection were still statistically significant. These results, together with previous data obtained in humans, revealed that metabolic factors may play a role in the synergism between viral hepatitis and chemical hepatocarcinogens in the etiopathogenesis of PHC.
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PMID:Enhanced metabolic activation of chemical hepatocarcinogens in woodchucks infected with hepatitis B virus. 272 Sep 3

Rabbit antiserum to Pre-S1 protein was used to establish peroxidase-antiperoxidase (PAP) and avidin-biotin-peroxidase complex (ABC) immunohistochemical techniques for detection of Pre-S1 protein in paraffin-embedded liver tissue. Pre-S1 protein could be expressed in hepatocyte cytoplasm and on membrane in some cases with chronic viral hepatitis, cirrhosis and hepatocellular carcinoma (HCC), and its expression was intimately associated with HBsAg, HBcAg in liver and HBV DNA in serum, indicating that pre-S1 protein may represent the essential component of hepatitis B virus (HBV) and also serve as one of the markers of HBV infection. The incidence of Pre-S1 protein was slightly lower in nontumorous liver of HCC than in other cases and Pre-S1 protein could not be detected in tumorous tissue of HCC suggesting that expression of pre-S1 protein may be suppressed in HCC cases.
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PMID:A preliminary study on expression and significance of pre-S1 protein in liver tissue of patients with HBV infection. 276 Sep 66

The identification and characterization of collagenous and non-collagenous glycoproteins have made it possible to use specific antibodies as tools for the topographical localization of the various connective tissue components, and thus to follow the progression of parenchymal-stromal interactions. This investigation is an approach to the study of in vivo relationships between basement membrane components (type IV collagen, laminin) and neoplastic cells of hepatocellular carcinoma. Ten cases of hepatic carcinomas were analysed and paraffin-embedded sections were immunostained with anti-laminin and anti-type IV collagen antibodies. The avidin-biotin-peroxidase complex technique was used. In well differentiated neoplasms with hepatic tumour cells organized in a trabecular pattern lined by sinusoid structures, type IV collagen was always detected at the sinusoidal level. Laminin was evident only in two cases with a prominent intraparenchymal vascular bed. In less differentiated neoplasms, sinusoids were almost absent and only large tumour vessels were positive for both laminin and type IV collagen. At the interface between tumour tissue and the surrounding stroma, some carcinomatous elements were surrounded by laminin and type IV collagen. Our data further support the hypothesis that basement membrane phenotypic expression may be influenced both by the degree of tumour differentiation and by the characteristics of the micro-environment.
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PMID:Hepatocellular carcinoma: expression of basement membrane glycoproteins. An immunohistochemical approach. 282 85


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