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)

Liver cirrhosis is often preceded by overt signs of hepatitis, including parenchymal cell inflammation and infiltration of polymorphonuclear (PMN) leukocytes. Activated PMNs release both reactive oxygen species and reactive halogen species, including hypochlorous acid (HOCl), which are known to be significantly cytotoxic due to their oxidizing potential. Because the role of mitochondria in the hepatotoxicity attributed to HOCl has not been elucidated, we investigated the effects of HOCl on mitochondrial function in the human hepatoma HepG2 cell line, human fetal liver cells, and isolated rat liver mitochondria. We show here that HOCl induced mitochondrial dysfunction, and apoptosis was dependent on the induction of the mitochondrial permeability transition (MPT), because HOCl induced mitochondrial swelling and collapse of the mitochondrial membrane potential with the concomitant release of cytochrome c. These biochemical events were inhibited by the classical MPT inhibitor cyclosporin A (CSA). Cell death induced by HOCl exhibited several classical hallmarks of apoptosis, including annexin V labeling, caspase activation, chromatin condensation, and cell body shrinkage. The induction of apoptosis by HOCl was further supported by the finding that CSA and caspase inhibitors prevented cell death. For the first time, these results show that HOCl activates the MPT, which leads to the induction of apoptosis and provides a novel insight into the mechanisms of HOCl-mediated cell death at sites of chronic inflammation.
 ...
PMID:Hypochlorous acid-mediated mitochondrial dysfunction and apoptosis in human hepatoma HepG2 and human fetal liver cells: role of mitochondrial permeability transition. 1591 86

Kahalalide F (KF) is a small natural peptide that showed activity in vitro and in vivo. The dose-limiting toxicity in clinical trials was transaminitis. We investigated the cytotoxicity of KF in cell lines from breast, ovary, prostate and colon cancers, but focused on hepatoma cell lines, performing mechanistic studies in HepG2 (IC50 = 0.3 microM) and PLC/PRF/5C (IC50 = 5 microM). Following KF exposure, HepG2 cells demonstrated profound ATP depletion, associated with cell swelling and cell blebbing, and increased permeability to propidium iodide (PI), annexin V (AV) and release of lactate dehydrogenase (LDH). PLC/PRF/5C cells retained their cell structure, but were permeable to PI and, following exposure to high concentrations of KF, to AV. The pattern of cell permeability is similar to maitotoxin, another small cytotoxic peptide, but the differential effects on the cell membrane induced by KF in HepG2 and PLC/PRF/5C suggest specific interactions with membranes or proteins. This could lead to better drug design aimed at exploiting the potential for cell selectivity.
 ...
PMID:The mechanism of action of Kahalalide F: variable cell permeability in human hepatoma cell lines. 1595 13

Our previous study showed that arsenic trioxide (As2O3) was effective in inhibiting the growth of human hepatocellular carcinoma (HepG2) cells via induction of apoptosis. In the present study, we examined the effect of As2O3 on multidrug resistant human hepatocellular carcinoma (R-HepG2) cells which are characterized with overexpression of mdr1 gene and P-glycoprotein. The anti-proliferation of R-HepG2 by As2O3 was examined by MTT assay. For the induction of apoptosis, DNA fragmentation and Annexin V-PI staining were performed after treatment with arsenic trioxide. To study the effect of arsenic trioxide on P-glycoprotein, Western analysis probing anti-P-glycoprotein antibody was used to monitor the change of its expression. Results showed that As2O3 was effective in inhibiting the cell proliferation of R-HepG2 cells in a dose- and time-dependent manner via induction of apoptosis without affecting the cell cycle. The sensitivity of R-HepG2 cells toward As2O3 was found to be similar to that of the parental HepG2 cells. The Western analysis showed that As2O3 was probably not the substrate to be bound and extruded by P-glycoprotein in R-HepG2 cells because it could not maintain the cellular P-glycoprotein expression.
 ...
PMID:Effect of arsenic trioxide on multidrug resistant hepatocellular carcinoma cells. 1598 6

The bisecting N-acetylglucosamine (GlcNAc) structure, formed through catalysis by UDP-N-acetylglucosamine : beta-D-mannoside beta-1,4-N-acetylglucosaminyltansferase III (GnT-III), is responsible for a variety of biological functions. We have previously shown that annexin V, a member of the calcium/phospholipid-binding annexin family of proteins, has binding activity toward the bisecting GlcNAc structure. In this study, we reported on a search for potential target glycoproteins for annexin V in a rat hepatoma cell line, M31. Using a glutathione S-transferase (GST)-annexin V immobilized sepharose 4B affinity column to trap interacting proteins produced by the GnT-III-transfected M31 cells, we isolated a 47 kDa protein. It was identified as Hsp47 by an N-terminal sequence analysis. Immunoprecipitation experiments showed that annexin V interacted with Hsp47. The association of annexin V and Hsp47 was abolished by treatment with N-glycosidase F or preincubation with sugar chains containing bisecting GlcNAc, suggesting that the bisecting GlcNAc plays an important role in the interaction. An oligosaccharide analysis of Hsp47 purified from GnT-III-transfected M31 cells was shown to have the bisecting GlcNAc structure, as detected by erythroagglutinating phytohemagglutinin (E4-PHA) and matrix assisted laser desorption/ionization-time of flight (MALDI-TOF) mass spectrometry (MS) analysis. Surface plasmon resonance analysis showed that annexin V was bound to Hsp47, bearing a bisecting GlcNAc with a Kd of 5.5 microM, whereas no significant binding was observed in the case of Hsp47 without a bisecting GlcNAc. In addition, immunofluorescence microscopy revealed the colocalization of annexin V, Hsp47, and a bisecting GlcNAc sugar chain around the Golgi apparatus. Collectively, these results suggest that the binding of annexin V to Hsp47 is mediated by a bisecting GlcNAc oligosaccharide structure and that Hsp47 is an intracellular ligand glycoprotein for annexin V.
 ...
PMID:Bisecting GlcNAc mediates the binding of annexin V to Hsp47. 1600 Jun 95

Phenylethyl isothiocyanate (PEITC) is a well recognized potential chemopreventive compound against human cancers. In this study, the molecular mechanism of PEITC-induced apoptosis was examined with two antioxidants (N-acetyl-cysteine and vitamin E) and a caspase-3 inhibitor (z-DEVD-fmk). Results demonstrated that PEITC significantly induced human hepatoma PLC/PRF/5 (CD95-negative) cells undergoing apoptosis. Treatment with 0 approximately 10 microM PEITC-triggered cell apoptosis as revealed by the externalization of annexin V-targeted phosphatidylserine and the subsequent appearance of sub-G1 population. Results also displayed that PEITC-induced apoptosis involves the up-regulation of p53 and Bax protein, down-regulation of the XIAP, Bcl-2, Bcl-(XL) and Mcl-1 proteins, cleavage of Bid, and the release of cytochrome c and Smac/Diablo, which were accompanied by the activation of caspases -9, -3 and -8. PEITC-induced the generation of reactive oxygen species and the decrease of mitochondrial membrane potential (Deltapsim) in a time-dependent pattern. N-acetyl-cysteine and vitamin E at 100 microM, and z-DEVD-fmk at 50 microM markedly blocked PEITC-induced apoptosis, which was demonstrated by a decline in the reactive oxygen species generation and the release of the cytochrome c and Smac/Diablo from mitochondria to the cytosol. N-acetyl-cysteine, vitamin E and z-DEVD-fmk also prevented the PEITC in inducing the loss of Deltapsim. They also affected the activity of XIAP and Bax proteins. Taken together, these studies suggest that PEITC is an apoptotic inducer that acts on the mitochondria and the feedback amplification loop of caspase-8/Bid pathways in PLC/PRF/5 cells.
 ...
PMID:Effects of antioxidants and caspase-3 inhibitor on the phenylethyl isothiocyanate-induced apoptotic signaling pathways in human PLC/PRF/5 cells. 1605 26

The liver is believed to be the primary clearance organ for coagulation proteases, including factor VIIa (FVIIa). However, at present, clearance mechanisms for FVIIa in liver are unknown. To obtain information on the FVIIa clearance mechanism, we investigated the binding and internalization of FVIIa in liver cells using a human hepatoma cell line (HEPG2), and primary rat and human hepatocytes as cell models. 125I-FVIIa bound to HEPG2 cells in a time- and dose-dependent manner. Anti-tissue factor antibodies reduced the binding by about 25%, whereas 50-fold molar excess of unlabeled FVIIa had no effect. HEPG2 cells internalized FVIIa with a rate of 10 fmol 10(-5) cells h(-1). In contrast to HEPG2 cells, FVIIa binding to primary rat hepatocytes was completely independent of TF, and excess unlabeled FVIIa partly reduced the binding of 125I-FVIIa to rat hepatocytes. Further, compared with HEPG2 cells, three- to fourfold more FVIIa bound to rat primary hepatocytes, and the bound FVIIa was internalized at a faster rate. Similar FVIIa binding and internalization profiles were observed in primary human hepatocytes. Plasma inhibitors had no effect on FVIIa binding and internalization in hepatocytes. In contrast, annexin V, which binds to phosphatidylserine, blocked the binding and internalization. Consistent with this, binding of gla-domain-deleted FVIIa to hepatocytes was markedly diminished. In summary, the data presented herein reveal differences between HEPG2 cells and primary liver cells in FVIIa binding and internalization, and suggest that the rapid turnover of membrane and not a receptor-mediated endocytosis may be responsible for internalization of FVII/FVIIa in primary hepatocytes.
 ...
PMID:Factor VIIa binding and internalization in hepatocytes. 1619 4

Conditionally replicative adenovirus (CRAd) mediated tumor specific gene therapy based on transcriptional control is considered a new direction for the treatment of cancer. Our previous studies showed that an HS4 insulator increased the alpha-fetoprotein (AFP) promoter-driven expression in the context of an adenovirus (Ad) vector, while retaining the highly specific gene expression in hepatoma cells in vitro and in vivo. In this study, we constructed two HS4-AFP promoter based CRAd vectors (Ad.HS4.AFP.E1a/TRAIL and Ad.HS4.AFP.E1a) with and without the expression cassette of TNF-related apoptosis-inducing ligand (TRAIL). The TRAIL-expressing virus vector, Ad.HS4.AFP.E1a/TRAIL, exhibited more obvious oncolytic effect than Ad.HS4.AFP.E1a in both high-AFP-producing HCC cell lines (Hep3B and HUH7) and a low-AFP-producing HCC cell line (PLC/PRF/5) examined, indicating endogenous TRAIL over-expression increased CRAd potency. The enhanced hepatoma cell death was mainly mediated through apoptotic mechanism, as evidenced by the activation of caspase-3, binding of annexin V and inhibition by caspase inhibitor z-vad-fmk. In s.c. xenograft of low-AFP-producing PLC/PRF/5 hepatoma model, the administration of Ad.HS4.AFP.E1a/TRAIL resulted in a more potent oncolytic effect compared with the same dose of Ad.HS4.AFP.E1a 28 days after virus exposure. This study demonstrated that the TRAIL in the context of a CRAd vector was able to increase the oncolytic activity in low-AFP-producing HCC cells in vitro and in vivo. Considering that oncolytic viruses destroy tumor cells expressing low levels of the tumor marker is a clinical concern, TRAIL might be a useful tool to improve the efficacy of these vectors.
 ...
PMID:Conditionally replicative adenovirus vector carrying TRAIL gene for enhanced oncolysis of human hepatocellular carcinoma. 1627 4

Ellipticine (5,11-dimethyl-6H-pyrido[4,3-b]carbazole), one of the simplest naturally occurring alkaloids, was isolated from the leaves of the evergreen tree Ochrosia elliptica Labill (Apocynaceae). Here, we reported that ellipticine inhibited the cell growth of human hepatocellular carcinoma cell line HepG2 and provided molecular understanding of this effect. The XTT assay results showed that ellipticine decreased the cell viability of HepG2 cells in a dose- and time-dependent manner, and the IC50 value was 4.1 microM. Furthermore, apoptosis induction by ellipticine in HepG2 cells was verified by the appearance of DNA fragmentation and annexin V-FITC/propidium iodide (PI) staining assay. Ellipticine treatment was found to result in the upregulation of p53, Fas/APO-1 receptor and Fas ligand. Besides, ellipticine also initiated mitochondrial apoptotic pathway through regulation of Bcl-2 family proteins expression, alteration of mitochondrial membrane potential (DeltaPsim), and activation of caspase-9 and caspase-3. Taken together, ellipticine decreased the cell growth and induced apoptosis in HepG2 cell.
 ...
PMID:Ellipticine induces apoptosis through p53-dependent pathway in human hepatocellular carcinoma HepG2 cells. 1633 42

Polypeptides in bee venom (PBV) produced a significant growth inhibition against SMMC-7721 human hepatoma cell line. Analysis of the mechanisms of cell death indicated that PBV induced an apoptotic cell death. SMMC-7721 cells exposed to PBV (10.0 microg mL(-1)) produced an insignificant morphological change. Analysis of the cytotoxicity with the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium) assay confirmed that the cytotoxic effects of PBV were dose- and timedependent. The result of Ki67 immunohistochemistry demonstrated that the proliferation of SMMC-7721 cells treated with PBV (10.0 mug mL(-1)) was inhibited. The apoptotic cell death was then confirmed by annexin V, propidium iodide staining and DNA fragmentation analysis. In in-vivo experiments, treatment with PBV (1.5 or 3 mg kg(-1)) resulted in a significant retardation of SMMC-7721 cell growth in Balb/c nude mice. These findings suggested that PBV could be used as a chemotherapeutic agent against tumours.
 ...
PMID:Effect of polypeptides in bee venom on growth inhibition and apoptosis induction of the human hepatoma cell line SMMC-7721 in-vitro and Balb/c nude mice in-vivo. 1639 67

Thymosin alpha1 (Talpha1), a 28-amino acid peptide, is a well-known immune system enhancer for the treatment of various diseases. In the present investigation, the effects of Talpha1 on the proliferation and apoptosis of human leukemia cell lines (HL-60, K562 and K562/ADM) were studied. The proliferation was significantly depressed after 96 h of treatment with Talpha1, and obvious signs of apoptosis, i.e., cell morphology, nuclei condensation and Annexin V binding, were observed thereafter. Moreover, the up-regulation of Fas/Apol (CD95) and decrease in bcl-2 anti-apoptotic gene expression were observed in apoptotic cells. The expression and the function of P-glycoprotein (P-gp) can be slightly inhibited by Talpha1. It is noteworthy that K562 and K562/ADM were more sensitive than HL-60 cells when subjected to Talpha1. Furthermore, HepG-2, the human hepatoma cell line, displayed significant less sensitivity to Talpha1 than all the human leukemia cell lines. D-Tubocurarine (TUB), a nicotinic acetylcholine receptors (nAChRs) antagonist, significantly antagonized the inhibition effects induced by Talpha1, whereas atropine, a muscarinic acetylcholine receptor antagonist, did not exhibit such effects. All the results indicate that Talpha1 was able to significantly suppress proliferation and induce apoptosis in human leukemia cell lines.
 ...
PMID:Thymosin alpha1 suppresses proliferation and induces apoptosis in human leukemia cell lines. 1664 63


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>