Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:2.4.2.30 (PARP)
13,611 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Combined treatment with quercetin and TRAIL induced cytotoxicity and enhanced annexin V staining and poly (ADP-ribose) polymerase (PARP) cleavage in human prostate cancer cell lines DU-145 and PC-3. These indicators of apoptosis resulted from the activation of caspase-8, -9, and -3. Although the expression levels of FLIPs, cIAP1, cIAP2, and the Bcl-2 family were not changed in quercetin-treated cells, significant downregulation of survivin occurred. Knockdown survivin by siRNA significantly increased TRAIL-induced apoptosis. We hypothesized that quercetin-induced activation of MAPK (ERK, p38, JNK) is responsible for downregulation of survivin gene expression. To test this hypothesis, we selectively inhibited MAPK during treatment with quercetin. Our data demonstrated that inhibitor of ERK (PD98059), but not p38 MAPK (SB203580) or JNK (SP600125), significantly maintained the intracellular level of survivin during treatment with quercetin. Interestingly, PD98059 also prevented quercetin-induced deacetylation of histone H3. Data from survivin promoter activity assay suggest that the Sp1 transcription factor binds to the survivin promoter region and quercetin inhibits its binding activity through deacetylation of histone H3. Quercetin-induced activation of the ERK-MSK1 signal transduction pathway may be responsible for deacetylation of histone H3. Taken together, our findings suggest that quercetin enhances TRAIL induced apoptosis by inhibition of survivin expression, through ERK-MSK1-mediated deacetylation of H3.
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PMID:Quercetin augments TRAIL-induced apoptotic death: involvement of the ERK signal transduction pathway. 1837 72

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a promising cancer therapeutic agent because of its tumor selectivity. TRAIL is known to induce apoptosis in cancer cells but spare most normal cells. In this study, we examined whether treatment of docetaxel (DTX) can enhance apoptotic cell death by TRAIL against androgen-independent prostate cancer (AIPC). The cell death effect of combinations of TRAIL and docetaxel on prostate cancer cell lines (androgen-dependent LNCaP and its derived androgen-independent, metastatic C4-2B) was evaluated by synergisms of apoptosis. Western blot assay and DNA fragmentation assay were used to study the underlying mechanisms of cell death and search for any mechanisms of enhancement of TRAIL induced apoptosis in the presence of docetaxel. In addition, we investigated the in vitro anti-tumor effects of combined docetaxel and TRAIL using MAP kinase inhibitors. Docetaxel itself could not induce apoptotic cell death in 24 h even in high concentration. Apoptotic cell death, however, was drastically enhanced by pretreatment of docetaxel 20 h before TRAIL treatment. Docetaxel enhanced the PARP-1 cleavage and caspases activation by TRAIL especially in androgen-independent, metastatic C4-2B cell line, mainly by phosphorylation of Bcl-2 by JNK activation. It appears that apoptotic cell death was protected by the JNK inhibitor SP600125. The results of our study show that pretreatment of docetaxel is able to enhance the apoptosis produced by TRAIL in prostate cancer cells, especially in hormone-refractory prostate cancer (HRPC).
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PMID:Pretreatment of docetaxel enhances TRAIL-mediated apoptosis in prostate cancer cells. 1840 75

The aim of this study was to investigate the effect of quercetin, a flavonoid, on the apoptotic pathway in a human prostate cell line (LNCaP). We observed that treatment of cells for 24h with quercetin-induced cell death in a dose-dependent manner. A sustained inhibition of the major survival signal, Akt, occurred in quercetin-treated cells. Treatment of LNCaP cells with an apoptosis inducing concentration of quercetin (100 microM) resulted in a rapid decrease in the inhibitory Ser473 phosphorylation of Akt leading to inhibition of its kinase activity. Quercetin treatment (100 microM) also caused a decrease in Ser136 phosphorylation of Bad, which is a downstream target of Akt. Protein interaction assay revealed that during treatment with quercetin, Bcl-xL dissociated from Bax and then associated with Bad. Our results also show that quercetin decreases the Bcl-xL:Bax ratio and increases translocation and multimerization of Bax to the mitochondrial membrane. The translocation is accompanied by cytochrome c release, and procaspases-3, -8 and -9 cleavage and increased poly(ADP-ribose) polymerase (PARP) cleavage. Similar results were observed in human colon cancer HCT116Bax+/+ cell line, but not HCT116Bax-/- cell line. Interestingly, at similar concentrations (100 microM), quercetin treatment did not affect the viability or rate of apoptosis in normal human prostate epithelial cell line (PrEC) and rat prostate epithelial cell line (YPEN-1). Our results indicate that the apoptotic processes caused by quercetin are mediated by the dissociation of Bax from Bcl-xL and the activation of caspase families in human prostate cancer cells.
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PMID:Role of Bax in quercetin-induced apoptosis in human prostate cancer cells. 1845 2

Mitochondrial dysfunction resulting from mitochondrial DNA (mtDNA) mutations and/or depletion has been correlated with cancer progression and drug resistance. To investigate the role of mtDNA in prostate cancer progression, we used LNCaP and PC-3 prostate carcinoma cells as experimental model. Compared to minimally invasive androgen-dependent LNCaP cells, highly invasive androgen-independent PC-3 cells, as well as androgen-independent DU145 and C4-2 cells, exhibited significantly reduced mtDNA content. In PC-3 cells, reduction of mtDNA was accompanied by decreased mitochondrial membrane potential (DeltaPsi(m)), increased migration onto the basement membrane protein laminin-1, reduced chemosensitivity to paclitaxel (IC(50)=110 nM vs. 22 nM) and decreased expression of poly(ADP-ribose) polymerase (PARP)-1. To investigate the relationship between mtDNA depletion and these phenotypic characteristics, we established mtDNA-depleted LNCaP cells [Rho(-)] by long-term exposure to ethidium bromide or treated wild-type LNCaP cells with a mitochondrial ionophore, carbonyl cyanide m-chlorophenylhydrazone. Both manipulations resulted in DeltaPsi(m) loss, acquisition of invasive cytology, increased motility onto laminin-1, reduced sensitivity to paclitaxel (IC(50)= approximately 100 nM) and approximately 75% reduction in PARP-1 protein levels, resembling PC-3 cells. Overall, these results provide novel evidence demonstrating that mtDNA depletion in early prostate carcinoma may contribute to the acquisition of a more invasive phenotype that is less sensitive to paclitaxel-induced apoptosis.
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PMID:Mitochondrial DNA depletion reduces PARP-1 levels and promotes progression of the neoplastic phenotype in prostate carcinoma. 1860 66

Development of effective agents for treatment of hormone-refractory prostate cancer (HRPC) has become a national medical priority. D-Allose is a monosaccharide (C-3 epimer of glucose) distributed rarely in nature; because of its scarcity and cost, the biological effect has hardly been studied. In the present study, we demonstrated the inhibitory action of D-allose on proliferation of human HRPC cell lines, DU145 and PC-3 in a dose- and time-dependent manner, while human normal prostate epithelial (NPE) cell line, PrEC showed no remarkable effect. In vitro treatment of D-allose resulted in the alteration of Bcl-2/Bax ratio in favor of apoptosis (programmed cell death, PCD) in both the HRPC cell lines, which was associated with the lowering of mitochondrial transmembrane potential (Deltapsi(m)) and the release of cytochrome C (cyt C), the cleavage of caspase 3 and poly (ADP-ribose) polymerase (PARP), and the elevation of calcium concentration in cytosol ([Ca(2+)](c)). D-Allose also induced G1 phase arrest of the cell cycle in DU145 cell line. This study for the first time suggested the antiproliferative effect of D-allose through induction of PCD in HRPC cell lines, which could be due to the modulation of mitochondria mediated intrinsic apoptotic pathway.
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PMID:Rare sugar D-allose induces programmed cell death in hormone refractory prostate cancer cells. 1862 5

Accumulating epidemiological data suggest that Asian men have lower incidences of prostate cancer and benign prostate hyperplasia (BPH) compared with American and European populations and may have benefited from their higher intake of phytoestrogens in their diet. However, how these phytochemicals affect prostatic diseases is still unclear. In this study, we isolated six lignans from a plant, Campylotropis hirtella (Franch.) Schindl., which has been used as a folk medicine for treatment of BPH in China, through bioassay guided fractionation. They were dehydrodiconiferyl alcohol (C1), 4-[(-6-hydroxy-2,3-dihydro-1-benzofuran-3-yl)methyl]-5-methoxybenzene-1,3-diol (C2), erythro-guaiacylglycerol-beta-O-4'-coniferyl ether (C3), threo-guaiacylglycerol-beta-O-4'-coniferyl ether (C4), secoisolariciresinol (C5), and prupaside (C6), where C2 was identified as a new lignan analog. Their IC50 values for inhibition of prostate specific antigen (PSA) secretion were 19, 45, 110, 128, 137, and 186 microM, respectively, from C1 to C6 in LNCaP cells. Further study showed that C1-5 down-regulated cellular PSA expression and C1-4 also decreased androgen receptor (AR) expression in LNCaP cells. Furthermore, we investigated the proapoptotic effect of C1 on LNCaP cells. The active forms of caspase 3 associated with the specific proteolysis of poly (ADP-ribose) polymerase (PARP) were detected, and the antiapoptotic protein Bcl-2 was down-regulated after the treatment with C1. These results collectively indicated that these lignans may have chemopreventive or therapeutic actions for prostate cancer through suppressing AR signaling pathway and inducing apoptosis.
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PMID:Lignans isolated from Campylotropis hirtella (Franch.) Schindl. decreased prostate specific antigen and androgen receptor expression in LNCaP cells. 1865 36

Inosine 5-monophosphate dehydrogenase II, a key enzyme in the de novo synthesis of purine nucleotides, is expressed in prostate tumors and prostate cancer cells. AVN944 is a new, specific, noncompetitive IMPDH inhibitor. In this study, we investigated the effects of IMPDH inhibitor AVN944 on LNCaP, CWR22Rv1, DU145 and PC-3 human prostate cancer cells. AVN944 inhibited proliferation of these 4 prostate cancer cell lines and was associated with cell cycle G1 arrest of LNCaP cells and S-phase block of androgen-independent CWR22Rv1, DU145 and PC-3 cells. AVN944 induced caspase-dependentand caspase-independent cell death in LNCaP, CWR22Rv1, and DU145 cells. AVN944 induced expression of p53-target proteins Bok, Bax and Noxa in androgen-responsive cell lines and suppressed expression of survivin in prostate cancer cells regardless of their androgen sensitivity. AVN944 also induced differentiation of androgen-independent prostate cancer cells as indicated by morphological changes and increased expression of genes coding for prostasomal proteins, keratins and other proteins, including tumor suppressor genes MIG-6 and NDRG1. AVN944-differentiated androgen-independent DU145 and PC-3 cells are sensitized to TRAIL-induced apoptosis as demonstrated by induction of caspases and PARP cleavage. In summary, AVN944 inhibited the growth of human prostate cancer cells by inducing cell cycle arrest, cell death as well as differentiation. AVN944 is a novel, promising therapeutic agent that might be combined with other agents for treatment of human prostate cancer.
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PMID:Antiproliferative effects of AVN944, a novel inosine 5-monophosphate dehydrogenase inhibitor, in prostate cancer cells. 1871 36

Benzylisothiocyanate (BITC), a major phase II enzyme inducer in the organic solvent of papaya fruit, has been shown to induce apoptosis specifically in cancer cells. The exposure of pancreatic, prostate as well as leukemic cells to this dietary isothiocyanate resulted in significant extent of apoptosis as evident from PARP cleavage, chromatin condensation or profound attenuation of procaspase-3 level. We also investigated whether BITC induces apoptosis by converging two major pathways: the death receptor mediated extrinsic and the mitochondrial intrinsic pathway. The exogenous expression of dominant-negative caspase-8 or dominant-negative caspase-9 can attenuate BITC-mediated cell death of prostate cancer cells. In parallel with this observation, BITC can activate both procaspase-8 and -9 in pancreatic and prostate cancer cells. Furthermore, flow cytometry analysis demonstrated the enrichment of sub-G0-G1 phase population with G2-M arrest in BITC challenged pancreatic cancer cells. In order to comprehend the molecular mechanism underlying the relationship between BITC-mediated cell cycle arrest and apoptosis we report here for the first time that the anti-apoptotic protein Bcl-xL was phosphorylated by BITC treatment. Subsequent investigation using Jun kinase inhibitor exhibits the involvement of Jun kinase in BITC triggered Bcl-xL phosphorylation and apoptosis.
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PMID:Dietary isothiocyanate mediated apoptosis of human cancer cells is associated with Bcl-xL phosphorylation. 1881 78

The present study examined the anti-proliferative effects of piplartine on the human prostate cancer cell line PC-3. This is the first report demonstrating the piplartine anti-cancer activity toward prostate cancer cell lines, although its precise mechanism of action is still not completely defined. In MTT assays, it preferentially inhibited growth of androgen-independent PC-3 cells in a dose-dependent (3-30 microM) and time-dependent (12-48 h) manner. In PC-3 cells, it showed an IC50 of 15 microM after 24 h of treatment. After a 24-30 microM treatment for 24 h, there were some reduction of cell volume, cell vacuolization, chromatin condensation and increased number of apoptotic cells visible by light and fluorescence microscopy. Agarose gel electrophoresis revealed that cells treated with piplartine exhibited DNA fragmentation. In addition, growth inhibition of PC-3 cells was associated with G2/M arrest and sub-G1 accumulation. Higher concentrations (24-30 microM) of piplartine modulated apoptosis-related protein expression by down-regulating cdc-2 expression and up-regulating PARP/procaspase-3 cleavage. Also, PC-3 cells treated with piplartine demonstrated caspase-3 activation, as observed with an in vitro caspase-3 colorimetric assay kit. Taken together, these results demonstrated that high concentrations of piplartine exhibited anti-proliferative and anti-cancer effects on PC-3 cells and that caspase-3-mediated PARP cleavage and cell cycle arrest at G2/M phase are involved in the underlying cellular mechanism of the apoptosis process.
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PMID:Piplartine induces caspase-mediated apoptosis in PC-3 human prostate cancer cells. 1881 19

Saussurea lappa (SL) is a plant regularly utilized in traditional herbal medicine, and in vitro cell culture studies have demonstrated that SL has anti-ulcer, anti-inflammatory, and anti-tumor properties. In order to explore the possibility that SL exerts chemopreventive effects in androgen-independent prostate cancer, we attempted to determine whether the hexane extract of SL (HESL) induces apoptosis of DU145 cells, as well as the mechanisms underlying this effect. HESL substantially reduced the number of viable cells and induced apoptosis in DU145 cells in a dose-dependent manner. HESL-induced the cleavage of poly (ADP-ribose) polymerase (PARP) and caspases 8, 9, 7, and 3. HESL increased the protein levels of Bax, Bak, Bok, Bik, truncated Bid (t-Bid), and Bmf with a concomitant increase in the permeability of the mitochondrial membrane and in the release of cytochrome c from the mitochondria. The active fraction of HESL was isolated by column chromatography and the structure of the active compound dehydrocostus lactone (DHCL) was identified via (1)H NMR and (13)C NMR. DHCL promoted apoptosis with increased activation of caspases 8, 9, 7, 3, enhanced PARP cleavage, decreased Bcl-xL expression and increased levels of Bax, Bak, Bok, Bik, Bmf, and t-Bid. We have demonstrated that HESL and its active principle, DHCL, inhibit cell growth and induce apoptosis in DU145 cells.
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PMID:Apoptosis of DU145 human prostate cancer cells induced by dehydrocostus lactone isolated from the root of Saussurea lappa. 1884 68


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