Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P10415 (Bcl-2)
 33,771 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Human mesenchymal stem cells (hMSCs) can home to tumor sites and inhibit the growth of tumor cells. Little is known about the underlying molecular mechanisms that link hMSCs to the targeted inhibition of tumor cells. In this study, we investigated the effects of hMSCs on two human hepatoma cell lines (H7402 and HepG2) using an animal transplantation model, a co-culture system and conditioned media from hMSCs. Animal transplantation studies showed that the latent time for tumor formation was prolonged and that the tumor size was smaller when SCID mice were injected with H7402 cells and an equal number of Z3 hMSCs. When co-cultured with Z3 cells, H7402 cell proliferation decreased, apoptosis increased, and the expression of Bcl-2, c-Myc, proliferating cell nuclear antigen (PCNA) and survivin was downregulated. After treatment with conditioned media derived from Z3 hMSC cultures, H4702 cells showed decreased colony-forming ability and decreased proliferation. Immunoblot analysis showed that beta-catenin, Bcl-2, c-Myc, PCNA and survivin expression was downregulated in H7402 and HepG2 cells. Taken together, our findings demonstrate that hMSCs inhibit the malignant phenotypes of the H7402 and HepG2 human liver cancer cell lines, which include proliferation, colony-forming ability and oncogene expression both in vitro and in vivo. Furthermore, our studies provide evidence that the Wnt signaling pathway may have a role in hMSC-mediated targeting and tumor cell inhibition.
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PMID:Suppression of tumorigenesis by human mesenchymal stem cells in a hepatoma model. 1836 78

Anthocyanins extracted from the berries of Phillyrea latifolia L., Pistacia lentiscus L., and Rubia peregrina L., three evergreen shrubs widely distributed in the Mediterranean area, were examined for their antioxidant and anticancer activity. The P. lentiscus anthocyanins showed the highest H(2)O(2) and 1,1-diphenyl-2-picryl-hydrazil radical scavenging effects, indicating that these compounds can be considered as an alternative source of natural antioxidants for food and pharmaceutical products. Here, we also report a novel function of anthocyanins: the induction of autophagy, a process of subcellular turnover involved in carcinogenesis. Autophagy was characterized by the up-regulation of eIF2alpha, an autophagy inducer, and down-regulation of mTOR and Bcl-2, two autophagy inhibitors. This led to the enhanced expression of LC3-II, an autophagosome marker in mammals, and monodansylcadaverine incorporation into autolysosomes. Anthocyanin-induced autophagy switched to apoptosis, as shown by the activation of Bax, cytochrome c and caspase 3, terminal deoxynucleotide transferase-mediated dUTP nick-end labeling-positive fragmented nuclei, and cells with sub-G(1) DNA content, which were prevented by z-VAD. Inhibition of autophagy by either 3-methyladenine or Atg5 small interfering RNA enhanced anthocyanin-triggered apoptosis. This provided evidence that autophagy functions as a survival mechanism in liver cancer cells against anthocyanin-induced apoptosis and a rationale for the use of autophagy inhibitors in combination with dietary chemopreventive agents.
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PMID:Autophagy inhibition enhances anthocyanin-induced apoptosis in hepatocellular carcinoma. 1872 93

The present study investigated the effect of mammalian target of rapamycin (mTOR) inhibition on HCC cells in vitro and in vivo, either alone or in combination with cytotoxic agents. In vitro, HCC cell lines were exposed to RAD001, an mTOR inhibitor, either alone or in combination with cisplatin. Alone, RAD001 suppressed cell proliferation in all cell lines tested, but did not induce apoptosis. RAD001 in combination with cisplatin induced a significant increase in the number of apoptotic cells, downregulated the expression of pro-survival molecules, Bcl-2, survivin and cyclinD1, and increased the cleavage of PARP, compared to RAD001 or cisplatin alone. Transfection of p53 into the Hep3B cell line increased the sensitivity of tumor cells to cisplatin. The suppression of HCC tumor growth in vivo was enhanced by RAD001 combined with cisplatin, accompanied by a significant increase in the number of apoptotic cells in tumor tissues. This study demonstrates that inhibition of mTOR suppresses tumor growth and sensitizes tumor cells to chemocytotoxic agents.
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PMID:Inhibition of mTOR enhances chemosensitivity in hepatocellular carcinoma. 1882 93

It has recently been shown that cannabinoids induce growth inhibition and apoptosis in different tumour cell lines. In the current study, the effects of WIN 55,212-2 (WIN), a synthetic and potent cannabinoid receptor agonist, are investigated in hepatoma HepG2 cells and a possible signal transduction pathway is proposed. In these cells, WIN induces a clear apoptotic effect which was accompanied by up-regulation of the death-signalling factors Bax, Bcl-X(S), t-Bid and down-regulation of the survival factors survivin, phospho-AKT, Hsp72 and Bcl-2. Moreover, WIN-induced apoptosis is associated with JNK/p38 MAPK pathway activation and mitochondrial depolarisation demonstrated by a cytofluorimetric assay. The results also show that in HepG2 cells WIN markedly increases the level of the transcription factor PPARgamma in a dose- and time-dependent manner. The addition of the PPARgamma antagonists GW9662 and T0070907 significantly reduces the effects of the drug on both cell viability and the levels of survivin, phospho-AKT and phospho-BAD, suggesting that PPARgamma plays a key role in WIN-induced apoptosis. Altogether, the results seem to indicate a potential therapeutic role of WIN in hepatic cancer treatment.
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PMID:Apoptosis induced in HepG2 cells by the synthetic cannabinoid WIN: involvement of the transcription factor PPARgamma. 1905 57

Hepatocellular carcinoma (HCC) is one of the most common cancers and lethal diseases. In view of the limited treatment and a grave prognosis of liver cancer, preventive control has been emphasized. Resveratrol, a polyphenol found in grape skins, peanuts, berries and red wine, has been shown to possess potent growth inhibitory effects against various human cancer cells. Although resveratrol has been found to exhibit chemopreventive actions in experimentally induced skin, breast, colon and esophagus rodent tumors, chemopreventive potential of this dietary constituent has not been explored well against experimental liver cancer. We evaluated the inhibitory effect of resveratrol using a two-stage model of rat hepatocarcinogenesis in Sprague-Dawley rats. Initiation was performed by a single intraperitoneal injection of diethylnitrosamine (DENA, 200 mg/kg), followed by promotion with phenobarbital (0.05%) in drinking water. The rats had free access to food supplemented with resveratrol equivalent to 50, 100 or 300 mg/kg body weight/day. Resveratrol treatment was started 4 weeks prior to the initiation and continued for 20 weeks. Resveratrol dose-dependently reduced the incidence, total number and multiplicity of visible hepatocyte nodules. Mean nodular volume and nodular volume as percentage of liver volume were also inhibited upon resveratrol treatment. Histopathological examination of liver tissue confirmed the protective effect of resveratrol. Immunohistochemical detection of cell proliferation and assay of apoptosis indicated a decrease in cell proliferation and increase of apoptotic cells in the livers of resveratrol-supplemented rats. Resveratrol also induced the expression of pro-apoptotic protein Bax, reduced anti-apoptotic Bcl-2 expression, with a concurrent increase in Bax/Bcl-2 ratio with respect to DENA control. The present study provides evidence, for the first time, that resveratrol exerts a significant chemopreventive effect on DENA-initiated hepatocarcinogenesis through inhibition of cell proliferation and induction of apoptosis. Resveratrol-induced apoptogenic signal during rat liver carcinogenesis may be mediated through the downregulation of Bcl-2 and upregulation of Bax expression. Due to a favorable toxicity profile, resveratrol can potentially be developed as a chemopreventive drug against human HCC.
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PMID:Resveratrol-mediated chemoprevention of diethylnitrosamine-initiated hepatocarcinogenesis: inhibition of cell proliferation and induction of apoptosis. 1907 62

Phloretin (Ph), a natural product found in apples and pears with glucose transporter (GLUT) inhibitory activity, exerts antitumor effects. However, little is known about its effects on human liver cancer. The purpose of this study is to test the cytotoxic effects of Ph on HepG2 cells and to identify the underlying molecular pathways. Human hepatocellular carcinoma specimens and HepG2 show a high level of GLUT2 transporter activity in the cell membrane. Real-time PCR and MTT assays demonstrate that Ph-induced cytotoxicity correlates with the expression of GLUT2. Flow cytometry and DNA fragmentation studies show that 200 microM Ph induces apoptosis in HepG2, which was reversed by glucose pretreatment. GLUT2 siRNA knockdown induced HepG2 apoptosis, which was not reversed by glucose. Western blot analysis demonstrates that both intrinsic and extrinsic apoptotic pathways in addition to Akt and Bcl-2 family signaling pathways are involved in Ph-induced cell death in HepG2 cells. Furthermore, using flow cytometry analysis, a mitochondrial membrane potential assay and Western blot analysis, we show that cytochalasin B, a glucose transport inhibitor, enhances the Ph-induced apoptotic effect on HepG2 cells, which was reversed by pretreatment with glucose. Furthermore, we found significant antitumor effects in vivo by administering Ph at 10 mg/kg intraperitoneally to severe combined immune deficiency mice carrying a HepG2 xenograft. A microPET study in the HepG2 tumor-bearing mice showed a 10-fold decrease in (18)F-FDG uptake in Ph-treated tumors compared to controls. Taken together, these results suggest that Ph-induced apoptosis in HepG2 cells involves inhibition of GLUT2 glucose transport mechanisms.
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PMID:In vitro and in vivo study of phloretin-induced apoptosis in human liver cancer cells involving inhibition of type II glucose transporter. 1912 83

This study is the first to investigate the anticancer effect of dehydrocostuslactone [DHE (3aS,6aR,9aR,9bS)-decahydro-3,6,9-tris(methylene) azuleno[4,5-b]furan-2(3H)-one)], a medicinal plant-derived sesquiterpene lactone, on hepatocellular carcinoma. Our results showed that DHE inhibits the proliferation of HepG2 and PLC/PRF/5 cells by inducing apoptosis. DHE induces up-regulation of Bax and Bak, down-regulation of Bcl-2 and Bcl-XL, and nuclear relocation of the mitochondrial factors apoptosis-inducing factor (AIF) and endonuclease G (Endo G). DHE triggered endoplasmic reticulum (ER) stress, as indicated by changes in cytosol-calcium levels, double-stranded RNA-activated protein kinase-like endoplasmic reticulum kinase phosphorylation, inositol-requiring protein 1 (IRE1) and CHOP/GADD153 up-regulation, X-box transcription factor-1 mRNA splicing, and caspase-4 activation. Enhancement of ER stress by DHE is through p38 and extracellular signal-regulated kinase 1/2-dependent manners and subsequently causes c-Jun NH(2)-terminal kinase activation, resulting in AIF and Endo G nuclear relocation. Both of IRE1 small interfering RNA transfection and 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid-acetoxymethyl ester pretreatment inhibit DHE-mediated apoptosis, supporting the hypothesis that DHE induces cell death through ER stress. It is noteworthy that animal studies have revealed a dramatic 50% reduction in tumor volume after 45 days of treatment. This study demonstrates that DHE may be a novel anticancer agent for the treatment of liver cancer.
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PMID:Dehydrocostuslactone, a medicinal plant-derived sesquiterpene lactone, induces apoptosis coupled to endoplasmic reticulum stress in liver cancer cells. 1918 81

Chlorella vulgaris (CV) has been reported to have antioxidant and anticancer properties. We evaluated the effect of CV on apoptotic regulator protein expression in liver cancer-induced rats. Male Wistar rats (200~250 g) were divided into eight groups: control group (normal diet), CDE group (choline deficient diet supplemented with ethionine in drinking water to induce hepatocarcinogenesis), CV groups with three different doses of CV (50, 150, and 300 mg/kg body weight), and CDE groups treated with different doses of CV (50, 150, and 300 mg/kg body weight). Rats were sacrificed at various weeks and liver tissues were embedded in paraffin blocks for immunohistochemistry studies. CV, at increasing doses, decreased the expression of anti-apoptotic protein, Bcl-2, but increased the expression of pro-apoptotic protein, caspase 8, in CDE rats, which was correlated with decreased hepatocytes proliferation and increased apoptosis as determined by bromodeoxy-uridine (BrdU) labeling and terminal deoxynucleotidyl transferase mediated dUTP nick-end labeling (TUNEL) assay, respectively. Our study shows that CV has definite chemopreventive effect by inducing apoptosis via decreasing the expression of Bcl-2 and increasing the expression of caspase 8 in hepatocarcinogenesis-induced rats.
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PMID:Chlorella vulgaris triggers apoptosis in hepatocarcinogenesis-induced rats. 1919 18

Conventional chemotherapy of liver cancer fails to provide satisfactory remission and may cause serious side effects, thus it is crucial to derive alternative treatments that effectively inhibit cancer cell growth with known mechanisms of action. In the present study, we investigated the anti-carcinogenic effects of Coptis chinensis and its major constituent, berberine, in HepG2 hepatocellular carcinoma (HCC) cells and attempted to elucidate the underlying mechanism, including involvement of the nonsteroidal anti-inflammatory drug (NSAID)-activated gene (NAG-1). Inhibition of cell proliferation, induction of apoptosis and cell cycle arrest at the G2/M phase were observed in HepG2 cells treated with Coptis chinensis or berberine. The pro-apoptotic effects were associated with corresponding down-regulation of Bcl-2, activation of procaspase-3 and -9 as well as cleavage of poly (ADP-ribose) polymerase. We further demonstrated the involvement of NAG-1 in the pro-apoptotic events following prior activation of its upstream transcriptional factor early growth response gene (Egr-1). This was confirmed by increased NAG-1 promoter activity preceded by the elevation of Egr-1/ DNA binding activity. Our results suggest that both Coptis chinensis and berberine are potential anti-carcinogenic agents in treating HCC by inducing cell cycle arrest and promotion of apoptosis, while NAG-1 is a molecular target during the drug-induced pro-apoptotic action in HepG2 cells.
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PMID:Coptis chinensis inhibits hepatocellular carcinoma cell growth through nonsteroidal anti-inflammatory drug-activated gene activation. 1972 99

The interactions of a ruthenium porphyrin complex [(Py-3')TPP-Ru(phen)(2)Cl]Cl (phen=1,10-phenanthroline, (Py-3')TPP=5-(3'-pyridyl-10,15,20-triphenylporphyrin) (1) and its heterometallic derivatives, [Ni(Py-3')TPP-Ru(phen)(2)Cl][PF(6)] (2) and [Cu(Py-3')TPP-Ru(phen)(2)Cl][PF(6)] (3), with calf thymus DNA have been investigated by spectroscopic and viscosity measurements in this study. The results showed that these synthetic complexes can bind to double strand helix DNA in groove binding mode, and the intrinsic binding constants of complexes 1, 2 and 3, as calculated according to the decay of the Soret absorption, are (1.35+/-0.5) x10(5)M(-1) (s=4.2), (1.29+/-0.5)x10(5)M(-1) (s=5.6) and (1.22+/-0.5)x10(5)M(-1) (s=6.2) (s is the binding-site size), respectively, which are consistent with those obtained from ethidium bromide-quenching experiments. Further investigations on the photocleavage properties of these complexes on plasmid pBR 322 DNA showed that complexes 1, 2 and 3 could cleave single chain DNA and convert DNA molecules from supercoiled form to the nicked form. As determined by MTT assay, the complexes were also identified as potent antiproliferative agents against A375 human melanoma cells, MCF-7 human breast adrenocarcinoma cells, Colo201 human colon adenocarcinoma cells and HepG2 human liver cancer cells. Complex 1 inhibits the growth of A375 cells through induction of apoptotic cell death and G0/G1 cell cycle arrest. Further investigation on intracellular mechanisms indicated that Complex 1 induced depletion of mitochondrial membrane potential (DeltaPsi(m)) in A375 cells through regulating the expression of pro-survival and pro-apoptotic Bcl-2 family members. Our results suggest that ruthenium porphyrin complexes could be candidates for further evaluation as chemopreventive and chemotherapeutic agents for human cancers.
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PMID:DNA binding and photocleavage properties and apoptosis-inducing activities of a ruthenium porphyrin complex [(Py-3')TPP-Ru(phen)2Cl]Cl and its heterometallic derivatives. 1995 51


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