Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0019204 (hepatocellular carcinoma)
 71,386 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Exposure of cells to toxic chemicals is known to up-regulate the expression of a number of stress proteins (SPs), including metallothionein (MT) and members of the heat shock protein (HSP) family, and this response may allow the development of a fingerprint profile to identify mechanisms of toxicity in an in vitro toxicology setting. To test this hypothesis, three hepatic-derived cell culture systems (rat hepatoma FGC4 cell line, rat hepatocytes, human hepatoma HepG2 cell line) were exposed to cadmium (as CdCl2) and arsenic (as NaAsO2), two compounds believed to exert their toxicity through an oxidative stress mechanism, under conditions of phenotypic anchoring defined as minimal and mild toxicity (approximately 5 and 25% reduction in neutral red uptake, respectively). The expression of six SPs--MT, HSP25/27, HSP40, HSP60, HSP70, and HSP90--was then determined by ELISA. Expression of four of these SPs--MT, HSP25/27, HSP40 and HSP70--was up-regulated in at least one experimental condition. However, the patterns of expression of these four SPs varied across the experimental conditions, according to differences in toxicant concentration and/or level of toxicity, cell-type and toxicant itself. This lack of uniformity in response of a focussed set of mechanistically defensible targets suggests that similar problems may emerge when using more global approaches based on genomics and proteomics, in which problems of redundancy in targets and uncertain mechanistic relevance will be greater.
 ...
PMID:Phenotypic anchoring of arsenic and cadmium toxicity in three hepatic-related cell systems reveals compound- and cell-specific selective up-regulation of stress protein expression: implications for fingerprint profiling of cytotoxicity. 1672 91

Liver, a central organ responsible for the metabolism of carbohydrates, proteins, and lipoproteins, is exposed to various kinds of physiological, pathological, and environmental stresses. We hypothesized that blockage of proteasome degradation pathway induces heat shock protein (HSP) response and unfolded protein response in the liver cells. In this study, we have characterized cellular responses to proteasome inhibition in HepG2 cells, a well-differentiated human hepatoma cells. We found that proteasome inhibition induced differential response among cytosolic HSPs, that is, increased expression of HSP70, but no change in HSP40, HSC70, and HSP90. However, proteasome inhibition did not induce typical unfolded protein response as indicated by absence of stimulation of GRP78 and GRP94 proteins. Upon proteasome inhibition, inclusion bodies were accumulated, and ubiquitin-conjugated proteins appeared in insoluble fraction, together with HSP40, HSP70, HSC70, and HSP90. After proteasome inhibition, misfolded proteins were increased in the cytosol and in the ER compartment as evaluated by examining ubiquitin-conjugated proteins. However, essentially all ER-associated ubiquitin-conjugated proteins were located on the surface of the ER, which explains why proteasome inhibition does not induce unfolded protein response. In conclusion, proteasome inhibition induces differential HSP response, but not unfolded protein response in HepG2 cells. Our study also suggests that HSPs play important roles in directing proteasomal degradation and protein aggregate formation.
 ...
PMID:Proteasome inhibition induces differential heat shock protein response but not unfolded protein response in HepG2 cells. 1676 95

Plasma membranes from normal rat liver and hepatocellular carcinoma Morris hepatoma 7777 were selectively solubilized by use of different reagents. After selective solubilization, proteins were identified by nano-HPLC-electrospray ionization tandem mass spectrometry (LC-ESI MS/MS). Using simple software, the patterns of proteins identified in membrane solubilizates from liver and hepatoma were compared. Proteins identified in Morris hepatoma 7777 and not in the corresponding membrane solubilizate from liver, mostly members of the annexin and heat shock protein families, are discussed as potential candidate markers for hepatocellular carcinomas.
 ...
PMID:Comparative proteomics of rat liver and Morris hepatoma 7777 plasma membranes. 1698 16

We have recently reported that attenuated phosphorylation of heat shock protein (HSP) 27 correlates with tumor progression in patients with hepatocellular carcinoma (HCC). In the present study, we investigated what kind of kinase regulates phosphorylation of HSP27 in human HCC-derived HuH7 cells. 12-O-tetradecanoylphorbol-13-acetate (TPA) and 1-oleoyl-2-acetylglycerol, direct activators of protein kinase C (PKC), markedly strengthened the phosphorylation of HSP27. Bisindorylmaleimide I, an inhibitor of PKC, suppressed the TPA-induced levels of HSP27 phosphorylation in addition to its basal levels. Knock down of PKCdelta suppressed HSP27 phosphorylation, as well as p38 mitogen-activated protein kinase (MAPK) phosphorylation. SB203580, an inhibitor of p38 MAPK, suppressed the TPA-induced HSP27 phosphorylation. Our results strongly suggest that activation of PKCdelta regulates the phosphorylation of HSP27 via p38 MAPK in human HCC.
 ...
PMID:Protein kinase C delta regulates the phosphorylation of heat shock protein 27 in human hepatocellular carcinoma. 1767 62

We conducted a case-control study to elucidate the role of heat shock protein A1B (HSPA1B) 1267 single nucleotide polymorphism (SNP) on the risk and prognosis of hepatocellular carcinoma (HCC). Subjects enrolled included 150 pairs of sex- and age-matched HCC patients and unrelated controls. Genomic DNA was typed for HSPA1B1267 SNP using polymerase chain reaction with restriction fragment length polymorphism. The frequencies of the HSPA1B P2/P2 genotype and the HSPA1B P2 allele in HCC patients were higher than in unrelated controls (each p = 0.0001). Multivariate analysis identified the following independent risk factors for HCC: HSPA1B P1/P2 genotype (odds ratio [OR], 2.34; 95% confidence interval [CI], 1.07-5.11), HSPA1B P2/P2 genotype (OR, 12.06; 95% CI, 4.43-32.79), hepatitis B surface antigen (HBsAg) (OR, 25.95; 95% CI, 11.88-56.68), and antibodies to hepatitis C virus (anti-HCV) (OR, 70.43; 95% CI, 21.89-226.64). There was an additive interaction between HSPA1B P2 allele carriers and the presence of either HBsAg (synergy index = 2.48) or anti-HCV (synergy index = 1.52). However, as HSPA1B1267 SNP is a silent mutation, it is a surrogate genetic marker for increasing risk of HCC. Our findings indicate that patients with chronic hepatitis B/hepatitis C virus infection who harbor this SNP represent a high-risk group for HCC. They should receive more intensive surveillance for early detection of HCC. Moreover, patients with the HSPA1B P2 allele had significantly longer survival (p = 0.002).The limitations of this study include the unknown functional significance of the HSPA1B1267 polymorphism, the relatively small sample size, the fact that this was not a prospective study of cases and controls, and the questionable generalizability of the findings given the specific ethnic composition of the population studied.
 ...
PMID:Heat shock protein A1B 1267 polymorphism is highly associated with risk and prognosis of hepatocellular carcinoma: a case-control study. 1834 6

Human Vdelta2 gammadelta T lymphocytes killed multiple solid tumors, even displaying comparable therapeutic efficacy with anti-tumor chemical-cis-platinum in an adoptive experiment in both nude and SCID murine model shown in present study. We previously found that T cell receptor (TCR) gammadelta recognize tumors via complementarity-determining region 3 (CDR3), briefly named as CDR3delta. Based on characteristics of specific binding of CDR3delta to tumor targets, we developed a novel tumor-targeting antibody, whose CDR3 in heavy chain is replaced by CDR3delta sequence derived from human ovarian carcinoma (OEC) infiltrating gammadelta T cells (gammadeltaTILs). This CDR3delta-grafted antibody OT3 exhibited specific binding activities to OEC line SKOV3 both in vitro and in vivo, which included specific binding to several tumor cell lines, interacting with heat shock protein (HSP) 60 and triggering ADCC against tumors in vitro, as well as displaying tumor imaging by radioisotope 99mTc-labeled antibody OT3 in vivo. Moreover, immunotoxin OT3-DT, CDR3delta-grafted antibody OT3 chemically conjugated with diphtheria toxin (DT) showed the anti-tumor effect on the growth of several solid tumors including OEC, cervix adenocarcinoma, hepatocellular carcinoma, and rectum adenocarcinoma to various extents in nude mice. Therefore, we have found and confirmed a novel therapeutic strategy for targeting solid tumors, making use of immune recognition characteristics of gammadelta T cells.
 ...
PMID:Targeting solid tumors via T cell receptor complementarity-determining region 3delta in an engineered antibody. 1878 50

Insulin regulates metabolism and growth in cells of hepatic origin by specifically binding to and activating the tyrosine kinase insulin receptor. Insulin-induced intracellular signaling is conducted via multiple pathways, including the MAP kinase (MEK/ERK) and the phosphatidylinositol 3-kinase (PI3K) pathways, which in turn activate multiple downstream signaling molecules. Heat shock protein 60 (HSP60; chaperonin 60kD) was selected by screening to be regulated by insulin in rat hepatoma cells. Heat shock proteins are a family of molecular chaperones whose main cellular function is to mediate the proper folding of newly synthesized proteins. The cellular response to stress is characterized by an overall decrease in protein synthesis, and upregulation of the heat shock protein family, including HSP60. A role for HSP60 has been implied in many diseases and in the responses to hypoxia. The present study was designed to ask whether insulin stimulated HSP60 gene expression. The rate of HSP60 transcription and mRNA accumulation were measured in rat H4IIE hepatoma cells and insulin-induced expression of HSP60 was predominantly via the MEK/ERK pathway. Inhibition of the p38 and PI3K pathways suggest complex feedback interactions of other insulin-, cell stressor- and cytokine- regulated pathways on the primary role of the MEK/ERK signaling in the regulation of HSP60 gene expression by insulin.
 ...
PMID:Insulin Dependant Gene Expression of Heat Shock Protein 60 in H4IIE Hepatoma Cells. 1907 90

Ochratoxin A (OTA) is a mycotoxin currently detected in stored animal and human food supplies as well as in human sera worldwide. OTA has diverse toxicological effects; however, the most prominent one is the nephrotoxicity. The present investigation was conducted to determine the molecular aspects of OTA toxicity in cultured human hepatocellular carcinoma cells. With this aim, we have monitored the effects of OTA on (i) cell viability, (ii) heat shock protein expressions as a parameter of protective and adaptive response, (iii) oxidative damage, and (iv) cell death signaling pathway. Our results clearly showed that OTA treatment inhibits cell proliferation, downregulates Hsp 70 and Hsp 27 protein and mRNA levels, and did not induce a significant reactive oxygen species generation. We have also demonstrated a decrease in mitochondrial membrane potential, a cytochrome c release, and an activation of caspase 9 and caspase 3 in response to OTA exposure. Moreover, OTA activates p53 expression, while some of its transcriptional target genes (Bax, Bak, PUMA, and p21) were found to downregulate. According to these data, we concluded that OTA may exert an inhibitory action on the transcriptional process. Besides, oxidative damage is not a major contributor to OTA toxicity. This mycotoxin induces a mitochondrial and caspase-dependent apoptotic cell death, which seems to be mediated by p53 transcriptional independent activities.
 ...
PMID:Toxicities induced in cultured human hepatocarcinoma cells exposed to ochratoxin A: oxidative stress and apoptosis status. 1936 35

Tetrazanbigen (TNBG) is a novel synthetic antitumor drug with significant antitumor effects on common solid tumors in vitro and in vivo. It may lead to death of cancer cells through a tumor-associated lipoidosis mechanism, and result in lipid droplets (LDs) accumulation at the cytoplasm. In this study, the effects of TNBG on protein expression in human hepatocellular carcinoma cell line QGY-7701 were studied for elucidating its antitumor mechanism. The proteins extracted from TNBG-treated human hepatocellular carcinoma cell line QGY-7701 were analyzed and compared with control cells by two-dimensional gel electrophoresis. The differential proteins were identified by matrix-associated laser desorption ionization time-of-flight mass (MALDI-TOF-MS) spectrometry. Two proteins of interest, the levels of which were significantly increased in TNBG-treated cells, were further characterized by Western blot analysis. The results showed a total of 846+/-23 spots in control cells and 853+/-30 spots in TNBG-treated cells. Twenty-six up-regulated or down-regulated proteins were found by analyzing differential proteomic 2-DE map. Eleven of them were identified by mass spectrometry. They were protein disulfide-isomerase precursor, 94 kD glucose-regulated protein, heat shock protein (HSP) 90-alpha, ATP-citrate lyase, HMG-CoA reductase, glucose-6-phosphate 1-dehydrogenase, very-long-chain specific acyl-CoA dehydrogenase, squalene synthetase, sterol regulatory element-binding protein 1, fructose-bisphosphate aldolase A, and peroxiredoxin-1. These up-regulated or down-regulated proteins are mostly related to lipid metabolism. The TNBG antitumor mechanism is probably to influence tumor lipid metabolism, resulting in accumulation of LDs in tumor cells.
 ...
PMID:Effects of tetrazanbigen on the protein expression in human hepatocellular carcinoma cell line QGY-7701. 1951 11

The heat shock (HS) response is a protective mechanism for cells to protect themselves against subsequent lethal stress. HS upregulated heat shock protein (HSP) expression reduced apoptosis following tumor necrosis factor-alpha (TNF-alpha) stimulation. However, vector-mediated overexpression of HSP70 failed to provide similar protection but rather sensitized cells to TNF-alpha induced apoptosis. This may be due to the fact that the kinetics of vector-mediated HSP overexpression is totally different from that of HSP upregulation by HS. We hypothesized that the response depends on the timing of TNF-alpha challenge relative to HSP expression dynamics after HS. Therefore, we investigated the correlation between the dynamic change of HSP expression and the levels of apoptosis induced by TNF-alpha after HS. Hepatoma cells were subjected to mild heat shock at 42 degrees C for 2 h followed by varied recovery times and then treated with TNF-alpha to induce apoptosis. The results from quantitative apoptosis assays using the TUNEL reaction reveal an optimal HS protection window centered around 5 h post-HS against TNF-alpha induced apoptosis. In addition, we found a window extending up to 2 h after HS where HS sensitized cells to TNF-alpha stress. Importantly, the correlation between apoptosis and HSP expression kinetics demonstrates that both high levels of HSPs and proper timing between HS and TNF-alpha stress were critical for optimal protection. Our study establishes a dynamic experimental model for further investigation of HS as a potential clinical approach to target tissue survival or death.
 ...
PMID:Dynamic effect of heat shock pretreatment on apoptotic responses to TNF-alpha in liver cells. 1964 Jan 28


<< Previous 1 2 3 4 5 6 7 8 9 Next >>