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)

Caspase-3 is responsible for the cleavage of several proteins including the nuclear enzyme poly(ADP-ribose) polymerase (PARP). Designed on the cleavage site of PARP, Ac-Asp-Glu-Val-Asp-H has been reported as a highly specific inhibitor. To overcome the susceptibility to proteolysis, the intrinsic instability, and the scarce membrane permeability of tetra-peptidyl aldehydes, di- and tri-peptidyl caspase-3 inhibitors have been synthesized. Here, the synthesis and the inhibition properties of peptidyl aldehydes Z-tLeu-Asp-H, Z-tLeu-Val-Asp-H, and Z-Val-tLeu-Asp-H are reported. Z-tLeu-Asp-H, Z-tLeu-Val-Asp-H, and Z-Val-tLeu-Asp-H inhibit competitively human caspase-3 activity in vitro with K(i)(0)=3.6nM, 18.2nM, and 109nM, respectively (pH 7.4 and 25 degrees C). Moreover, Z-tLeu-Asp-H impairs apoptosis in human DLD-1 colon adenocarcinoma cells without affecting caspase-8. Therefore, Ac-Asp-Glu-Val-Asp-H can be truncated to Z-tLeu-Asp-H retaining nanomolar inhibitory activity in vitro and displaying action in whole cells, these properties reflect the unprecedented introduction of the bulky and lipophilic tLeu residue at the P(2) position.
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PMID:Human caspase-3 inhibition by Z-tLeu-Asp-H: tLeu(P2) counterbalances Asp(P4) and Glu(P3) specific inhibitor truncation. 1885 75

Selenocystine (SeC) is a nutritionally available selenoamino acid with selective anticancer effects on a number of human cancer cell lines. The present study shows that SeC inhibited the proliferation of human breast adenocarcinoma MCF-7 cells in a time- and dose-dependent manner, through the induction of cell cycle arrest and apoptotic cell death. SeC-induced S-phase arrest was associated with a marked decrease in the protein expression of cyclins A, D1, and D3 and cyclin-dependent kinases (CDKs) 4 and 6, with concomitant induction of p21waf1/Cip1, p27Kip1, and p53. Exposure of MCF-7 cells to SeC resulted in apoptosis as evidenced by caspase activation, PARP cleavage, and DNA fragmentation. SeC treatment also triggered the activation of JNK, p38 MAPK, ERK, and Akt. Inhibitors of ERK (U0126) and Akt (LY294002), but not JNK (SP600125) and p38 MAPK (SB203580), suppressed SeC-induced S-phase arrest and apoptosis in MCF-7 cells. The findings establish a mechanistic link between the PI3K/Akt pathway, MAPK pathway, and SeC-induced cell cycle arrest and apoptosis in MCF-7 cells.
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PMID:Selenocystine induces S-phase arrest and apoptosis in human breast adenocarcinoma MCF-7 cells by modulating ERK and Akt phosphorylation. 1895 17

Pyrogallol (PG) is a polyphenol compound and a known O2- generator. We evaluated the effects of PG on the growth and apoptosis of human pulmonary adenocarcinoma Calu-6 cells. PG decreased the viability of Calu-6 cells in a dose- and time-dependent manner. The induction of apoptosis by PG was accompanied by the loss of mitochondrial membrane potential (DeltaPsi(m)), cytochrome c release from mitochondria and activation of caspase-3 and caspase-8. All tested caspase inhibitors, especially the pan-caspase inhibitor (Z-VAD), markedly rescued Calu-6 cells from PG-induced cell death. Rescue was accompanied by inhibition of caspase-3 activation and PARP cleavage. Treatment with Z-VAD also prevented the loss of mitochondrial membrane potential (DeltaPsi(m)). In conclusion, PG inhibits the growth of Calu-6 cells via caspase-dependent apoptosis.
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PMID:Pyrogallol inhibits the growth of lung cancer Calu-6 cells via caspase-dependent apoptosis. 1900 Jun 62

Pyrogallol, a catechin compound, is an active component of Emblica officinalis extracts and has an anti-proliferative effect on some human cancer cell lines. In our preliminary study, pyrogallol had highly cytotoxic effect on human lung cancer cell lines and less effect on human bronchial epithelium cell line. This study was performed to investigate the beneficial effect of pyrogallol on human lung cancer cell lines - H441 (lung adenocarcinoma) and H520 (lung squamous cell carcinoma). The MTT (cytotoxic) data showed the inhibition growth of lung cancer cells followed pyrogallol treatment. The cell cycle of lung cancer cells was arrested in G2/M phase using flow cytometry. Using Western blot analysis, the cell cycle related proteins - cyclin B1 and Cdc25c were decreased in a time-dependent manner and the phosphorylated Cdc2 (Thr14) was increased within 4h pyrogallol treatment. Moreover, the higher cleavage of poly (ADP)-ribose polymerase (PARP), the increased of Bax concurrent with the decreased of Bcl-2 indicated that pyrogallol treatment resulted in apoptosis of lung cancer cells. The cell apoptosis was also directly demonstrated using Annexin V-FITC and TUNEL stain. Additionally, the tumoricidal effect of pyrogallol was measured using a xenograft nude mice model. After 5 weeks of pyrogallol treatment could cause the regression of tumor. Taken in vitro and in vivo studies together, these results suggest that pyrogallol can be developed as a promising anti-lung cancer drug particular for the non-small cell lung cancer (NSCLC).
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PMID:Pyrogallol induces G2-M arrest in human lung cancer cells and inhibits tumor growth in an animal model. 1923 5

Erucin (ER) is a dietary isothiocyanate present in cruciferous vegetables, such as rocket salads (Erucasativa Mill., Diplotaxis sp.), that has been recently considered a promising cancer chemopreventive phytochemical. Biological activity of ER was investigated on human lung adenocarcinoma A549 cells, analyzing its effects on molecular pathways involved in apoptosis and cell cycle arrest, such as PARP-1 cleavage, p53 and p21 protein expression. Our results show that ER affects the A549 cell proliferation, enhancing significantly p53 and p21 protein expression in a dose-dependent manner (p<0.001). PARP-1 cleavage occurs only after exposure to high concentrations of ER (50 microM), in accordance to previous studies showing similar bioactivity of other isothiocyanates (ITCs). Our study reports for the first time that the induction of p53, p21 and PARP-1 cleavage may participate in the anti-proliferative activity of ER in human lung adenocarcinoma A549 cells. Comparison of data with those obtained with the isothiocyanate sulforaphane (SF), structurally related to ER, underlines the strong relationship between structural analogy of ITCs and their biological activity. The ability of dietary compounds to modulate molecular mechanisms that affect cancer cell proliferation is certainly a key point of the cancer prevention potential by functional foods.
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PMID:Erucin, a new promising cancer chemopreventive agent from rocket salads, shows anti-proliferative activity on human lung carcinoma A549 cells. 1932 33

Kahweol, the coffee-specific diterpene, has been reported to have anti-carcinogenic properties. Animal data support such a chemopreventive effect of coffee. However, the precise underlying protective mechanisms are poorly understood. In this study, the apoptotic effect of kahweol in human lung adenocarcinoma A549 cells was investigated. In cell viability assays and cell proliferation assays, kahweol exhibited anti-proliferative and pro-apoptotic effects on A549 cells in a time- and dose-dependent manner. Kahweol considerably inhibited the expression of Bcl-2 but increased that of Bax; it also stimulated the cleavage of caspase-3 and PARP (poly ADP-ribose polymerase). In addition, kahweol-induced apoptosis was confirmed by TUNEL assays. Furthermore, kahweol inhibited dose-dependent phosphorylation of signal transducer and activator of transcription 3 (STAT3). An overexpression in STAT3 led to resistance to kahweol-induced apoptosis, suggesting that STAT3 was a critical target of kahweol. These findings suggest that kahweol inhibited A549 cell growth and induced apoptosis via down-regulation of STAT3 signaling pathway.
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PMID:Kahweol blocks STAT3 phosphorylation and induces apoptosis in human lung adenocarcinoma A549 cells. 1942 40

Apoptosis is frequently regulated by different protein kinases including protein kinase C family enzymes. Both inhibitory and stimulatory effects were demonstrated for several of the different PKC isoforms. Here we show that the novel PKC isoform, PKCeta, confers protection against apoptosis induced by the DNA damaging agents, UVC irradiation and the anti-cancer drug--Camptothecin, of the breast epithelial adenocarcinoma MCF-7 cells. The induced expression of PKCeta in MCF-7 cells, under the control of the tetracycline-responsive promoter, resulted in increased cell survival and inhibition of cleavage of the apoptotic marker PARP-1. Activation of caspase-7 and 9 and the release of cytochrome c were also inhibited by the inducible expression of PKCeta. Furthermore, JNK activity, required for apoptosis in MCF-7, as indicated by the inhibition of both caspase-7 cleavage and cytochrome c release from the mitochondria in the presence of the JNK inhibitor SP600125, was also suppressed by PKCeta expression. Hence, in contrast to most PKC isoforms enhancing JNK activation, our studies show that PKCeta is an anti-apoptotic protein, acting as a negative regulator of JNK activity. Thus, PKCeta could represent a target for intervention aimed to reduce resistance to anti-cancer treatments.
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PMID:PKCeta confers protection against apoptosis by inhibiting the pro-apoptotic JNK activity in MCF-7 cells. 1952 67

Activation of poly(ADP-ribose) polymerase-1 (PARP1) has been shown to mediate cell death induced by genotoxic stimuli. The role of poly(ADP-ribose) glycohydrolase (PARG), the enzyme responsible for polymer degradation, has been largely unexplored in the regulation of cell death. Using lentiviral gene silencing we generated A549 lung adenocarcinoma cell lines with stably suppressed PARG and PARP1 expression (shPARG and shPARP1 cell lines, respectively) and determined parameters of apoptotic and necrotic cell death following hydrogen peroxide exposure. shPARG cells accumulated large amounts of poly(ADP-ribosyl)ated proteins and exhibited reduced PARP activation. Hydrogen peroxide-induced cell death is regulated by PARG in a dual fashion. Whereas the shPARG cell line (similarly to shPARP1 cells) was resistant to the necrotic effect of high concentrations of hydrogen peroxide, these cells exhibited stronger apoptotic response. Both shPARP1 and especially shPARG cells displayed a delayed repair of DNA breaks and exhibited reduced clonogenic survival following hydrogen peroxide treatment. Translocation of apoptosis-inducing factor could not be observed, but cells could be saved by methyl pyruvate and alpha-ketoglutarate, indicating that energy failure may mediate cytotoxicity in our model. These data indicate that PARG is a survival factor at mild oxidative damage but contributes to the apoptosis-necrosis switch in severely damaged cells.
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PMID:Dual role of poly(ADP-ribose) glycohydrolase in the regulation of cell death in oxidatively stressed A549 cells. 1957 Oct 39

Ceramides are central molecules in sphingolipid metabolism. They are involved in the regulation of cancer-cell growth, differentiation, senescence and apoptosis. To better understand how these secondary messengers induce their biological effects, adenocarcinoma cells (HCT116) were treated with exogenous long-chain ceramides (C16-ceramide) in order to mimic endogenous sphingolipids. This treatment induced a decrease of cell viability partly due to apoptosis as shown by PARP cleavage and a decrease of pro-caspase 3. Two-dimensional differential in-gel electrophoresis (2D-DIGE) revealed the differential expression of 51 proteins in response to C16-ceramide. These proteins are notably involved in cell proliferation, apoptosis, protein transport and transcriptional regulation. Among them, the cell death-promoting factor Btf was found to be implicated in the apoptotic signal triggered by ceramide. In adenocarcinoma cells, Btf regulates apoptosis related proteins such as Mdm2, p53, BAX and pBcl-2 and thus plays an important role in the ceramide mediated cell death. These findings bring new insight into the proapoptotic ceramide-dependent signaling pathway.
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PMID:The proapoptotic C16-ceramide-dependent pathway requires the death-promoting factor Btf in colon adenocarcinoma cells. 1970 20

A major germacranolide sesquiterpene lactone, deoxyelephantopin, identified from Elephantopus scaber L. (known as "Didancao" in Chinese medicine) showed significant antitumor growth and antimetastatic effect on murine mammary adenocarcinoma TS/A cells in vitro and in vivo in mice. Deoxyelephantopin exhibited a superior effect to that of the paclitaxel in prolonging median survival time of tumor-bearing animals in our recent study. To investigate the molecular mechanisms underlying the difference in efficacy between deoxyelephantopin and paclitaxel, we used 2-D DIGE and LC-ESI-MS/MS to profile proteins differentially expressed in the nucleus and cytoplasm of TS/A cells and used the MetaCore database to determine the functional protein networks affected by both treatments. Deoxyelephantopin and paclitaxel treatment produced regulation of molecules involved in proteolysis and calcium ion transport, suggesting the possible effects of both drugs on proteasome and endoplasmic reticulum machinery in TS/A cells. Western blot analysis of marker proteins (e.g., PDI, GRP78, TXND5, caspase-12, caspase-3 and PARP) further verified that induction of endoplasmic reticulum stress was associated with apoptosis induced by both deoxyelephantopin and paclitaxel, but only deoxyelephantopin inhibited proteasomal proteolysis in TS/A cells. The novel effects on targeting ER machinery and suppressing proteasome activity suggest the great potential of deoxyelephantopin for mammary cancer therapy.
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PMID:Differential proteomic profiling identifies novel molecular targets of paclitaxel and phytoagent deoxyelephantopin against mammary adenocarcinoma cells. 1989 75


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