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)

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

Poly(ADP-ribosyl)ation of transcription factors and coregulators, mediated by the poly(ADP-ribose) polymerase PARP-1, has been emerging as an important epigenetic mechanism that controls transcriptional dynamics in response to diverse intra- and extracellular signals. PARP-1 activity is also implicated in the regulation of mammalian lifespan. Herein we show that transcriptional down-regulation of androgen receptor (AR) in the aging rat liver and in oxidatively stressed hepatoma cells involves exchange of a PARP-1-associated, p/CAF-containing coactivator assembly for a p53-interacting, Groucho/TLE1-, and mSin3A-included corepressor complex at an age- and oxidant-responsive DNA element (age-dependent factor (ADF) element) in the AR promoter. The coregulator switch is mediated by B-Myb and c-Myb, which bind to the ADF element and physically associate with PARP-1 and the tumor suppressor p53. Heterogeneous nuclear ribonucleoprotein K, residing at the ADF element in association with PARP-1, may serve a platform role in stabilizing the activating complex. PARP-1 coactivated B-Myb- and c-Myb-mediated transactivation of the AR promoter, and p53 antagonized the B-Myb/c-Myb-induced AR promoter activation. PARP-1, heterogeneous nuclear ribonucleoprotein K, B-Myb, and c-Myb each serves as a positive regulator of cellular AR content, whereas p53 negatively regulates AR expression. Our results identify a shared, PARP-1-regulated sensing mechanism that coordinates transcriptional repression of AR during aging and in response to oxidative stress. This study may provide insights as to how advancing age and intracellular redox balance might influence androgen-regulated physiology.
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PMID:Loss of androgen receptor in aging and oxidative stress through Myb protooncoprotein-regulated reciprocal chromatin dynamics of p53 and poly(ADP-ribose) polymerase PARP-1. 1894 70

Bufotalin is one of the bufadienolides isolated from Formosan Ch'an Su, which is made of the skin and parotid glands of toads. Ingestion of toad venom results in severe morbidity and high mortality. Although Ch'an Su is clinically toxic, it has been used as an important traditional Chinese medicine for heart failure and pains. In this study, bufotalin-induced apoptosis in human hepatocellular carcinoma Hep 3B cells was investigated. The results indicate that externalization of phosphatidylserine, accumulation of sub-G(1) cells, fragmentation of DNA, and formation of apoptotic bodies were observed in bufotalin-treated Hep 3B cells. The signaling pathway might be via the activation of caspase-8, increase in mitochondrial tBid, disruption of mitochondrial membrane potential, and translocation of apoptosis-inducing factor (AIF). Active caspase-8 might activate caspase-9 and caspase-3 leading to the cleavage of nuclear PARP. Presence of AIF and cleaved PARP in the nuclei might lead to DNA fragmentation. Caspase-8 inhibitor (Z-IETD) or wide-ranging caspase inhibitor (Z-VAD) significantly suppressed the bufotalin-induced apoptosis, while the anti-Fas neutralization antibody had no effect. These data suggest that bufotalin-induced apoptosis in Hep 3B cells might involve caspases and AIF.
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PMID:Involvement of caspases and apoptosis-inducing factor in bufotalin-induced apoptosis of Hep 3B cells. 1905 67

Astragalus membranaceus has been used to ameliorate the side effects of anti-neoplastic drugs. We recently reported that total Astragalus saponins (AST) possess anti-tumor properties in human colon cancer cells and tumor xenografts. Nevertheless, the precise mechanism of action has not been fully elucidated. The present study aimed to unveil the anti-carcinogenic potential of AST in HepG2 human hepatocellular carcinoma (HCC) cells and to clarify the signaling pathway. We demonstrated here that AST downregulated expression of the HCC tumor marker alpha-fetoprotein and suppressed HepG2 cell growth by inducing apoptosis. AST also caused caspase activation, poly(ADP-ribose) polymerase (PARP) cleavage, nuclear chromatin condensation, with downregulation of the anti-apoptotic proteins bcl-2 and bcl-xL and decreased nuclear factor-kappa B (NF-kappaB)/DNA-binding activity. Concomitantly, expression of the phosphorylated form of the extracellular signal-regulated protein kinase (ERK) was prominently increased. Nevertheless, pretreatment of ERK inhibitor PD98059 did not attenuate AST-induced PARP cleavage. Taken together, these results exemplify that AST induced growth inhibition and promoted apoptosis in HepG2 cells through modulation of an ERK-independent NF-kappaB signaling pathway.
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PMID:Astragalus saponins induce apoptosis via an ERK-independent NF-kappaB signaling pathway in the human hepatocellular HepG2 cell line. 1914 42

We recently established that asparanin A, a steroidal saponin extracted from Asparagus officinalis L., is an active cytotoxic component. The molecular mechanisms by which asparanin A exerts its cytotoxic activity are currently unknown. In this study, we show that asparanin A induces G(2)/M phase arrest and apoptosis in human hepatocellular carcinoma HepG2 cells. Following treatment of HepG2 cells with asparanin A, cell cycle-related proteins such as cyclin A, Cdk1 and Cdk4 were down-regulated, while p21(WAF1/Cip1) and p-Cdk1 (Thr14/Tyr15) were up-regulated. Additionally, we observed poly (ADP-ribose) polymerase (PARP) cleavage and activation of caspase-3, caspase-8 and caspase-9. The expression ratio of Bax/Bcl-2 was increased in the treated cells, where Bax was also up-regulated. We also found that the expression of p53, a modulator of p21(WAF1/Cip1) and Bax, was not affected in asparanin A-treated cells. Collectively, our findings demonstrate that asparanin A induces cell cycle arrest and triggers apoptosis via a p53-independent manner in HepG2 cells. These data indicate that asparanin A shows promise as a preventive and/or therapeutic agent against human hepatoma.
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PMID:Asparanin A induces G(2)/M cell cycle arrest and apoptosis in human hepatocellular carcinoma HepG2 cells. 1925 88

The cytotoxic effect of the tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is limited in some carcinoma cancer cells. However, it was found that treatment with TRAIL in combination with nontoxic concentrations of genistein sensitized TRAIL-resistant human hepatocellular carcinoma Hep3B cells to TRAIL-mediated apoptosis. Combined treatment with genistein and TRAIL-induced chromatin condensation and sub-G1 phase DNA content. These indicators of apoptosis were correlated with the induction of caspase activity that resulted in the cleavage of poly(ADP-ribose) polymerase (PARP). Both cell viability and the cleavage of PARP induced by combined treatment were significantly inhibited by caspase-3, -8 and -9 inhibitors, which demonstrates the important roles of caspases in the observed cytotoxic effects. Genistein treatment also triggered the inhibition of p38-beta mitogen-activated protein kinase (MAPK) activation. Pretreatment with SB203580 resulted in significantly increased sub-G1 population and loss of mitochondrial membrane potential (MMP) in TRAIL-induced apoptosis. By contrast, overexpression of p38 MAPK protected apoptosis by co-treatment with genistein and TRAIL, suggesting that the p38 MAPK act as key regulators of apoptosis in response to treatment with a combination of genistein and TRAIL in human hepatocellular carcinoma Hep3B cells.
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PMID:Genistein enhances TRAIL-induced apoptosis through inhibition of p38 MAPK signaling in human hepatocellular carcinoma Hep3B cells. 1949 11

Hepatocellular carcinomas represent the third leading cause of cancer-related deaths worldwide. Survivin, a structurally unique member of the inhibitor of apoptosis protein (IAP) family, is overexpressed in a wide range of malignancies, including hepatocellular carcinoma. Due to its involvement in cancer progression and treatment resistance, survivin is currently undergoing extensive investigation as a novel intervention target to induce apoptosis in cancer cells by phytochemicals or synthetic agents. Brazilein, a compound obtained in a large amount from the dried heartwood of Caesalpinia sappan Linn., which has long been used in traditional medicine in China, has some pharmacological activities. Human hepatocellular carcinoma HepG2 cells were treated with brazilein and analyzed for survivin protein and mRNA levels by Western blotting and real-time RT-PCR, respectively. Brazilein treatment of cells for 48 h at 5 and 10 microg/ml doses resulted in significantly decrease in survivin protein expression. We also observed that brazilein caused a strong decrease in survivin mRNA expression. In other studies, down-regulation of survivin by brazilein was associated with a strong and prominent caspases-9 and -3 activation as well as PARP cleavage. It was also shown that brazilein induced a strong apoptotic cell death, as shown by DNA ladder assay, and growth inhibition of HepG2 cells. Further studies are needed to investigate in vivo effect of brazilein on survivin expression and associated biological effects in hepatocellular carcinoma that could provide useful information for brazilein efficacy in the prevention/intervention of human hepatocellular carcinoma.
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PMID:Brazilein inhibits survivin protein and mRNA expression and induces apoptosis in hepatocellular carcinoma HepG2 cells. 1958 Mar 39

Antrodia camphorata, unique fungal specie, has been used as a folk medicine in Taiwan for many years. The purpose of this study was to compare the extracts from the solid-state culture of A. camphorata co-fermented with Chinese medicinal herb (AC-CF) with two other extracts from fruiting bodies (AC-FB) or solid-state culture (AC-SS), for their anti-tumor effects in human hepatoma HepG2 cells. We measured in vitro cell proliferation, percentage of apoptosis, population distribution of cell cycles, Western blot analysis of multiple drugs resistance-1 (MDR-1), and apoptosis-related proteins in HepG2 cells treated with three different preparations of A. camphorate extracts. Our results showed that AC-CF had better anti-proliferation effect on human hepatoma HepG2 cells than AC-FB or AC-SS dose-dependently. In addition, AC-CF in combination with anti-tumor agents (mitomycin C or methotrexate) showed better adjuvant anti-tumor effects than AC-FB or AC-SS. We further demonstrated the augmented adjuvant anti-tumor effects of AC-CF not only through down regulation of MDR-1 expression but also through a COX-2 dependent apoptosis pathway, involving down-regulation of COX-2 and p-AKT and up-regulation of PARP-1. In conclusion, in this study, we have demonstrated a novel strategy of fermenting A. camphorata with Chinese medicinal herb (AC-CF), which augmented their anti-tumor effects in human hepatoma HepG2 cells as compared to the traditional ones (AC-FB or AC-SS).
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PMID:The augmented anti-tumor effects of Antrodia camphorata co-fermented with Chinese medicinal herb in human hepatoma cells. 1965 14

Insulin receptor substrate-4 (IRS-4) transmits signals from the insulin-like growth factor receptor (IGF-IR) and the insulin receptor (IR) to the PI3K/AKT and the ERK1/2 pathways. IRS-4 expression increases dramatically after partial hepatectomy and plays an important role in HepG2 hepatoblastoma cell line proliferation/differentiation. In human hepatocarcinoma, IRS-4 overexpression has been associated with tumor development. Herein, we describe the mechanism whereby IRS-4 depletion induced by RNA interference (siRNA) sensitizes HepG2 cells to treatment with actinomycin D (Act D) and combined treatment with Act D plus tumor necrosis factor-alpha (TNF-alpha). Similar results have been obtained in HuH 7 and Chang cell lines. Act D therapy drove the cells to a mitochondrial-dependent apoptotic program involving cytochrome c release, caspase 3 activation, PARP fragmentation and DNA laddering. TNF-alpha amplifies the effect of Act D on HepG2 cell apoptosis increasing c-jun N-terminal kinase (JNK) activity, IkappaB-alpha proteolysis and glutathione depletion. IRS-4 depleted cells that were treated with Act D showed an increase in cytochrome c release and procaspase 3 and PARP proteolysis with respect to control cells. The mechanism involved in IRS-4 action is independent of Akt, IkappaB kinase and JNK. IRS-4 down regulation, however, decreased gamma-glutamylcysteine synthetase content and cell glutathione level in the presence of Act D plus TNF-alpha. These results suggest that IRS-4 protects HepG2 cells from oxidative stress induced by drug treatment.
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PMID:RNAi-mediated silencing of insulin receptor substrate-4 enhances actinomycin D- and tumor necrosis factor-alpha-induced cell death in hepatocarcinoma cancer cell lines. 1979 87

The Hepatitis B virus (HBV) is a causative agent of acute chronic hepatitis, cirrhosis, and hepatocarcinoma. The Hepatitis B virus X protein (HBx) has pleiotypic functions in the regulation of proliferation and apoptosis. It has been suggested that the anti-inflammatory drug sulfasalazine, which is commonly used to treat rheumatoid arthritis and inflammatory bowel disease, inhibits nuclear factor NF-kappaB and induces cell death in HBx-expressing liver cells. In this study, we demonstrate that sulfasalazine induces cell death via apoptosis in HBx-expressing liver cells, as evidenced by characteristic changes in nuclear morphology, cleavage of poly (ADP-ribose) polymerase (PARP), caspase-3 and caspase-9, and activation of caspase-3. We also demonstrate that inhibition of NF-kappaB by siRNA fails to induce apoptosis of HBx-expressing liver cells, indicating that sulfasalazine modulates apoptosis of HBx-expressing cells in an NF-kappaB-independent manner.
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PMID:Sulfasalazine induces apoptosis of HBx-expressing cells in an NF-kappaB-independent manner. 1985 96


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