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)

Hepatocarcinogenesis may involve multiple mutations with distinctive pathogenetic and clinicopathologic significance. To test this hypothesis, 68 cases of hepatocellular carcinoma (HCC) were studied prospectively for genetic-clinicopathologic correlation. Ten pathologic characteristics were evaluated. TP53 (alias p53) gene mutation was studied by a polymerase chain reaction (PCR)-single-strand conformation polymorphism-sequencing; CDKN2B (alias p15) and CDKN2A (alias p16) gene methylation by methylation-specific PCR; and genetic imbalances by comparative genomic hybridization (CGH). TP53 gene mutations occurred in 25% of cases, more than half being codon 249 G to T transversion. Methylation of CDKN2A was frequent (61.7%); of CDKN2B, rare (5.9%). The CGH analysis showed a median of nine aberrations per case, with amplifications more frequent than deletions. Isochromosomes might be involved in about 25% of cases. Amplifications of 1q and 8q were most frequent. Clinicopathologic correlations showed that CDKN2A methylation was significantly associated with tumors arising in cirrhotic livers; amplifications of 17q was significant in multiple parameters of tumor invasiveness (size, venous invasion, poor cellular differentiation, microsatellite formation); other amplifications (1q, 6p, 10p, and 20p) were also significant in tumor invasion; and deletions (at 1p, 11q, 4q, and 14q) were significant in tumor growth. Consistent patterns of genetic alterations were defined in HCC, which might represent distinctive pathways in hepatocarcinogenesis.
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PMID:Clinicopathologic significance of genetic alterations in hepatocellular carcinoma. 1449 90

To determine the methylation profile of multiple tumor-related genes during multistep hepatocarcinogenesis, we investigated the methylation status of CpG islands of 9 genes, using methylation-specific polymerase chain reaction for 60 paired hepatocellular carcinoma (HCC) and non-HCC liver tissue samples, 22 dysplastic nodule (DN), 30 liver cirrhosis (LC), 34 chronic hepatitis (CH) and 20 normal liver samples. The methylation status of 9 genes was correlated to the clinicopathological findings of HCC patients. All HCC samples showed methylation of at least one gene, whereas it was shown in 72.7% of DN and 40% of LC, but was not shown in CH and normal liver samples (P < 0.001). The number of genes methylated showed a stepwise increase with the progression of stages (0 for normal liver and CH, 0.5 for LC, 1.5 for DN, and 3.7 for HCC (P < 0.001)). The genes frequently methylated in HCC were APC (81.7%), GSTP1 (76.7%), RASSF1A (66.7%), p16 (48.3%), COX-2 (35%), and E-cadherin (33.3%). COX-2, p16, RASSF1A, and TIMP-3 were not methylated in LC and CH from patients without concurrent HCC. Chronic liver diseases with concurrent HCC showed higher methylation frequencies of the tested genes, and a higher number of methylated genes than those without concurrent HCC. HCC patients with methylation of E-cadherin or GSTP1 showed poorer survival than those without (P = 0.034 and 0.043, respectively). In conclusion, our results indicated that CpG island methylation of tumor-related genes is an early and frequent event, and accumulates step-by-step during a multistep hepatocarcinogenesis. CpG island methylation of E-cadherin or GSTP1 might serve as a potential biomarker for prognostication of HCC patients.
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PMID:Aberrant CpG island hypermethylation along multistep hepatocarcinogenesis. 1450 45

A significant component of the general surgeon's practice is treatment of cancer that most commonly involves breast, colorectal, pancreas, and hepatic surgeries. The prognosis for these patients is largely dependent upon the stage of the disease at the time of diagnosis. There is convincing evidence that the induction and progression of cancer occurs when the function of genes that regulate cell proliferation, cell death and DNA repair becomes altered. These molecular disturbances result from ongoing, tumor-promoting activity long before symptoms of the disease become apparent. The role of many genes and the extent of their involvement in this deleterious, molecular process is unique to the organ. However, the tumor suppressor genes p53 and p16, the oncogene c-myc, and the inflammation-associated enzyme COX-2 are implicated in all four of the tumors. The roles of the oncogenes ras and HER-2/erbB-2/neu are significant in all of the tumors except hepatocellular carcinoma. The systematic establishment of a comprehensive data base relating gene expression activity to the initiation and development of cancer will provide molecular markers for detection and targets for treatment. This overview presents the current status of information associating gene expression activity with cancers typically encountered by general surgeons.
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PMID:Gene activity associated with cancers treated by surgical oncologists. 1461 4

The aim of this study was to investigate the effects of ginsenoside Rh(2) (G-Rh(2)) on differentiation of SMMC-7721 hepatocarcinoma cell line in culture. We studied G-Rh(2)-induced differentiation of SMMC-7721 cells through cell proliferation, cell morphology, ultrastructure, cell cycle, cell function and metabolism. The proliferation of treated cells was inhibited, the morphology and ultrastructure seemed normal, the secretory amount and expression of alpha-foetoprotein, and the specific activity of gamma-glutamyl transpeptidase, and heat-resistant alkaline phosphatase were all significantly decreased, the secretory amount of albumin and alkaline phosphatase activity were remarkably increased, and the cell was arrested at the G(1)/G(0) phase. Furthermore, G-Rh(2) induced elevated expression of the cyclin-dependent kinase inhibitor p21(WAF1) and p16(INK4a), and declined expressions of cyclin D1 and cyclin E. In addition, G-Rh(2) almost completely inhibited telomerase activity, as measured by polymerase chain reaction-based telomeric repeat amplification protocol coupled with enzyme-linked immune sorbent assay, and human telomerase reverse transcriptase mRNA. Based on these data, it is suggested that G-Rh(2) could induce cell differentiation tending to normal and effectively reduce telomerase activity with affecting transcription levels of human telomerase reverse transcriptase, paralleling the induction of cell differentiation.
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PMID:In vitro induction of differentiation by ginsenoside Rh2 in SMMC-7721 hepatocarcinoma cell line. 1467 61

In this study, the effects of HMBA on the expression of G0/G1 phase arrest-associated genes in human hepatocarcinoma SMMC-7721 cells were investigated. Immunocytochemistry and in situ hybridization assay revealed that the levels of p21WAF1/CIP1 and p16 proteins and the level of p21WAF1/CIP1 mRNA were increased while the levels of CDK4 and Cyclin D1 proteins and c-myc mRNA were decreased in the cells treated with HMBA. These results showed that HMBA could up-regulate the expression of p21WAF1/CIP1 and p16 genes, down-regulate the activity of Cyclin D1-CDK4 and the transcription of c-myc gene which were necessary for cells entering into S phase, and so arrest the cells in G0/G1 phase, and induce the differentiation of human hepatocarcinoma SMMC-7721 cells.
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PMID:[Effects of HMBA on the expression of cell-cycle-associated genes in human hepatocarcinoma SMMC-7721 cells]. 1534 77

Flow cytometric analysis of fibroblasts, normal breast epithelial cells and breast or other cancer cell lines identified variation in the abilities of cell lines to undergo cell cycle arrest as a response to hypoxia. Human mammary epithelial cells (HMEC), normal fibroblasts (Hs68 and WI38), HeLa cervical carcinoma and HTB-30 breast carcinoma cells arrest in G(1)/S in response to severe hypoxia. Hep3B hepatocellular carcinoma cells did not exhibit orderly G(1)/S arrest in response to severe hypoxia. We found a general decrease in p16(INK4a) (p16) mRNA levels, with an associated decrease in p16 protein levels in both normal cells and in cancer cells, regardless of their cell cycle response to hypoxia. p27 protein levels did not correlate with the cell line's ability to enter a hypoxic G(1)/S arrest. Furthermore, cell lines that underwent G(1)/S arrest showed decreased expression of hypoxia inducible factor 1 (HIF-1alpha) and at least one member of INK4 or Sdi cell cycle kinase inhibitors families after 12-24 h of hypoxia. Conversely, Hep3B, which did not exhibit orderly hypoxia-associated G(1)/S arrest, also did not show decreased HIF-1alpha, INK4 or Sdi protein levels in hypoxia. Furthermore, Hep3B showed constitutive activating phosphorylation of Akt and inhibitory phosphorylation of GSK3beta, which was the opposite pattern to that exhibited by the cell lines showing the G(1)/S arrest phenotype. Inhibition of GSK3beta by lithium chloride treatment of HeLa cells converted the HIF-1alpha, p16 and p27 loss to levels unchanged by hypoxic exposure. Our results suggest that regulation of the cell cycle during hypoxia in either normal or cancer cells is not simply due to up-regulation of cell cycle kinase inhibitors. Furthermore, decreased protein expression of HIF-1alpha, p16 and p27 was associated with both a hypoxia-induced G(1)/S arrest phenotype and increased GSK3beta activity.
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PMID:Cell cycle kinase inhibitor expression and hypoxia-induced cell cycle arrest in human cancer cell lines. 1534

We studied in vitro effects of glycogen synthase kinase 3beta (GSK3beta)-inhibitor lithium on the growth of hepatocellular carcinoma (HCC) cells. Lithium induced strong growth inhibition (> 70%) in 75% (n = 9 of 12) of cell lines, apparently independent from the status of major genes that are mutated in HCC including p53, p16(INK4a), beta-catenin and Axin1. Comparative studies with a growth-sensitive Huh7 and growth-resistant Hep40 cell lines showed that lithium induces growth arrest in Huh7 cells but not in Hep40 cells. Lithium induced the accumulation of N-terminally phosphorylated inactive form of GSK3beta with concomitant increase in beta-catenin and beta-catenin/TCF transcriptional activity in both cell lines. This suggests that lithium-mediated HCC growth inhibition is independent of its well-known stimulatory effect on Wnt-beta-catenin signaling. The main differences between Huh7 and Hep40 responses to lithium treatment were observed at the levels PKB/Akt and cyclin E proteins. Lithium induced depletion of both proteins in growth-sensitive Huh7, but not in growth-resistant Hep40 cells. PKB/Akt and Cyclin E are 2 major proteins that are known to be constitutively active in HCC. The targeting of both proteins with lithium may be the main reason why most HCC cells are responsive to lithium-mediated growth inhibition, independent of their p53, retinoblastoma and Wnt-beta-catenin pathways. The exploration of molecular mechanisms involved in lithium-mediated growth inhibition in relation with PKB/Akt and cyclin E downregulation may provide new insights for therapy of liver tumors.
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PMID:Lithium-mediated downregulation of PKB/Akt and cyclin E with growth inhibition in hepatocellular carcinoma cells. 1572 55

The signaling mechanisms for most of the antiproliferative processes are not fully understood. We have demonstrated that ERK(MAPK) signaling was involved in the induction of both p15(INK4b)and p16(INK4a) CDK inhibitors and growth inhibition of hepatoma cell HepG2 triggered by the tumor promoter tetradecanoyl phorbol acetate (TPA). In this study, the upstream signal mechanism for TPA-induced ERK(MAPK) activation was investigated. In HepG2 cells only one of the cPKC isozymes, PKCalpha, but not cPKCbetaII, nPKCepsilon or aPKCzeta was activated by TPA as demonstrated by its membrane translocation within 10-30 min and down-regulation at 24 h after TPA treatment. Pretreatment of 0.2-2.0 microM Bisindolylmaleimides, an inhibitor of PKC, attenuated the TPA-induced phosphorylation of ERK, gene expressions of p15(INK4b) and p16(INK4a), and growth inhibition of HepG2 cell in a dose-dependent manner. Consistently, transfection of HepG2 with 1.0-3.0 microM antisense (AS) PKCalpha, but not (AS) PKCbetaII, or nPKCepsilon oligonucleotides (ODN), for 36 h prior to TPA treatment also prevented the TPA-induced molecular and cellular effects described above. Taken together, we concluded that PKCalpha is specifically required for TPA-induced ERK(MAPK) signaling to trigger gene expressions of p15(INK4b) and p16(INK4a) leading to HepG2 growth inhibition.
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PMID:Activation of protein kinase C alpha is required for TPA-triggered ERK (MAPK) signaling and growth inhibition of human hepatoma cell HepG2. 1591 95

The clinical and morphological definition of hepatocellular carcinoma (HCC), dysplasia and adenoma suffers from a lack of biological understanding. This is especially important in the histomorphological diagnosis of nodular liver lesions in needle biopsies. Therefore, we constructed a liver tissue micro-array (TMA) and evaluated 48 HCCs, 46 dysplasias, 8 adenomas, 20 cirrhotic specimens and 28 normal liver samples derived from 68 patients. Protein (over)expression by tumor suppressor genes p16, p53 and Rb1 was assessed by immunohistochemistry, the proliferative capacity was examined by immunostaining of Ki67. Further, DNA ploidy status (hyperdiploidy) was measured by fluorescent in situ hybridization (FISH) with a chromosome 1-specific repetitive DNA probe. An abnormal chromosome 1 number, i.e. the percentage of hyperdiploid cells, was 11.0, 13.7, 16.1, 23.7 and 31.3 for normal liver samples, adenomas, cirrhosis, dysplasias and HCCs, respectively. A significant difference was found for HCC versus cirrhosis (P = 0.024) or adenoma (P = 0.033), a trend (borderline significance) was seen for dysplasia versus cirrhosis (P = 0.094). Immunohistochemical protein localisation of p53 and Rb1, as well as Ki67 indicating proliferation, was clearly higher in HCC than in cirrhosis or dysplasia (all P < 0.001). Proliferation was also higher in HCC than in adenoma (P = 0.025), whereas a trend (borderline significance) was observed for Rb1 overexpression (P = 0.063). These data suggest that in the liver cell dysplasia-carcinoma pathway, changes in ploidy are followed by increased proliferation and cell biological perturbations involving p53 and Rb1. Adenomas can be distinguished from carcinomas, but not from dysplasias, based on ploidy and proliferation characteristics.
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PMID:Cell biological evaluation of liver cell carcinoma, dysplasia and adenoma by tissue micro-array analysis. 1600 Feb 13

Hepatocyte growth factor (HGF) has an anti-proliferative effect on many types of tumor cell lines and tumors in vivo. We found previously that inhibition of HGF-induced proliferation in HepG2 hepatoma cells is caused by cell cycle arrest at G1 through a high intensity ERK signal, which represses Cdk2 activity. To examine further the mechanisms of G1 arrest by HGF, we analyzed the Cdk inhibitor p16(INK4a), which has an anti-proliferative function through cell cycle arrest at G1. We found that HGF treatment drastically increased endogenous p16 levels. Knockdown of p16 with small interfering RNA reversed the arrest, indicating that the induction of p16 is required for G1 arrest by HGF. Analysis of the promoter of the human p16 gene identified the proximal Ets-binding site as a responsive element for HGF, and this responded to the high intensity ERK signal. HGF treatment of the cells led to a redistribution of p21(CIP1) and p27(KIP1) from Cdk4 to Cdk2. The redistribution was blocked by the knockdown of p16 with small interfering RNA, which restored the Cdk2 activity repressed by HGF, demonstrating the requirement of p16 induction for the redistribution and eventual repression of Cdk2 activity. Our results reveal a signaling pathway for G1 arrest induced by HGF.
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PMID:Hepatocyte growth factor induces redistribution of p21(CIP1) and p27(KIP1) through ERK-dependent p16(INK4a) up-regulation, leading to cell cycle arrest at G1 in HepG2 hepatoma cells. 1601 26


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