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)

The objective of this study was to investigate the fermented culture broth of Antrodia camphorata (A. camphorata) to induce apoptosis and inhibit cyclooxygenase-2 (COX-2) in estrogen-nonresponsive (MDA-MB-231) human breast cancer cells. Treatment of the highly invasive MDA-MB-231 cells with A. camphorata (40-240 microg/ml) resulted in dose and time-dependent sequences of events marked by apoptosis, as evidenced by loss of cell viability, chromatin condensation, and internucleosomal DNA fragmentation. Apoptosis in the MDA-MB-231 cells was accompanied by release of cytochrome c, activation of caspase-3, -8, and -9, and specific proteolytic cleavage of poly (ADP-ribose) polymerase (PARP). Although the A. camphorata-induced apoptosis was associated with a reduction in Bcl-2 protein levels, negligible Bax increase was observed. Furthermore, A. camphorata treatment inhibited COX-2 protein expression and prostaglandin E2 (PGE2) production in MDA-MB-231 cells. Analysis of the study data suggests that A. camphorata exerts growth inhibition on (highly invasive) estrogen-nonresponsive human breast cancer cells through apoptosis induction associated with COX-2 inhibition, and that it may possess anticancer properties potentially valuable for application in drug products.
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PMID:Inhibition of cyclooxygenase-2 and induction of apoptosis in estrogen-nonresponsive breast cancer cells by Antrodia camphorata. 1739 24

Resveratrol (3,4',5-trans-trihydroxystilbene) is a natural compound found in grapes and several medicinal plants and has been shown to have anticancer effects on various human cancer cells. The aim of this study was to further investigate the molecular mechanism of this anticancer effect. Resveratrol effect on cell growth, morphology and gene expression was investigated in estrogen receptor-negative MDA-MB-231 human breast cancer cell line. We show here that resveratrol-induced growth inhibition in the estrogen receptor negative MDA-MB-231 breast cancer cells is due to the induction of apoptosis as demonstrated by morphological, nuclear staining and PARP cleavage analysis. Resveratrol-induced growth inhibition was associated with transient activation of p44/42 mitogen-activated protein kinase (MAPK) (Thr202/Tyr204). Most importantly, resveratrol inhibited both the phosphorylation at Ser240/244 and the expression of the pS6 ribosomal protein. This protein is known to play an important role in the translation of mRNAs that have oligopyrimidine tracts in their 5' untranslated regions. Interestingly, only MAPK inhibitor was able to block resveratrol-induced growth inhibition suggesting that effects of resveratrol on cell growth are dependent on MAPK signaling. The data demonstrated that resveratrol-induced apoptosis is associated with MAPK signaling and with the inhibition of proteins that are involved in protein translation. This is the first data linking resveratrol with downregulation of protein translation via p44/42 MAPK and S6 ribosomal protein. We propose to use these proteins as predictive biomarkers to evaluate the treatment efficacy of resveratrol in estrogen receptor-negative human breast cancer.
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PMID:Resveratrol-induced growth inhibition in MDA-MB-231 breast cancer cells is associated with mitogen-activated protein kinase signaling and protein translation. 1755 6

Poly(ADP-ribose) synthetase inhibitor, INO-1001, is known to sensitize cells to radiation in vitro by inhibiting the repair of DNA damage. Recent evidence has suggested that PARP inhibition may also be a way of selectively targeting p53 deficient cancer cells. The present study tested INO-1001 for its in vivo effect on the chemoresponse of two p53 deficient tumors, human breast cancer MDA-MB-231 and murine mammary carcinoma MCa-K. Doxorubicin was used as the DNA damaging agent and tumor growth delay assay was used as the endpoint. Results showed that INO-1001 was highly effective in enhancing the anti-tumor effects of Doxorubicin for both MDA-MB-231 (EF=1.88) and MCa-K (EF=1.64). We conclude that PARP inhibitor INO-1001 has high potential for enhancing the anti-tumor effects of chemotherapy agents such as Doxorubicin against p53 deficient breast cancer.
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PMID:INO-1001, a novel inhibitor of poly(ADP-ribose) polymerase, enhances tumor response to doxorubicin. 1762 43

The formation of reactive oxygen species (ROS) plays a critical role in 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-induced toxicities in mammalian cells since it promotes cell proliferation, growth arrest, and apoptosis. In this study, we investigated whether TCDD induces oxidative stress and DNA damage in human ERalpha(+)/MCF-7 and ERalpha(-)/MDA-MB-231 breast cancer cells and whether this is accompanied by the initiation of DNA repair events. Results indicated that viability of MCF-7 and MDA-MB-231 cells was concentration- and time-dependently reduced by TCDD. Further, we observed significant increases in ROS formation and decreases in intracellular glutathione (GSH) in these two cell lines after TCDD treatment. Overall, the extent of cell death was greater in MCF-7 cells than in MDA-MB-231 cells whereas the magnitude of ROS formation and GSH depletion was greater in MDA-MB-231 cells than in MCF-7 cells. In addition, we observed that at non-cytotoxic concentration (1nM for 5h), TCDD induced decreases in intracellular NAD(P)H and NAD(+) in MCF-7 and MDA-MB-231 cells. These decreases were completely blocked by three types of poly(ADP-ribose) polymerase-1 (PARP-1) inhibitors. The catalytic activation of PARP-1 in cells treated with TCDD was confirmed by detection of the presence of polymers of ADP-ribose-modified PARP-1 using Western blotting. Moreover, we demonstrated increases in the number of DNA strand breaks in MCF-7 and MDA-MB-231 cells exposed to TCDD as measured by the single-cell gel electrophoresis (Comet) assay. Overall, this evidence confirms that TCDD induces decreases in intracellular NAD(P)H and NAD(+) through PARP-1 activation mediated by formation of DNA strand breaks. In addition, we demonstrated that the extent of oxidative stress and DNA damage was greater in MDA-MB-231 cells than in MCF-7 cells, with a strong correlation to estrogen receptor (ER) status. In conclusions, our findings add further support to the theme that ROS formation is a significant determinant factor in mediating the induction of oxidative DNA damage and repair in human breast cancer cells exposed to TCDD and that the TCDD-induced oxidative stress and DNA damage may, in part, contribute to TCDD-induced carcinogenesis.
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PMID:2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) induces oxidative stress, DNA strand breaks, and poly(ADP-ribose) polymerase-1 activation in human breast carcinoma cell lines. 1766 6

Undecylprodigiosin (UP) is a bacterial bioactive metabolite produced by Streptomyces and Serratia. In this study, we explored the anticancer effect of UP. Human breast carcinoma cell lines BT-20, MCF-7, MDA-MB-231 and T47D and one nonmalignant human breast epithelial cell line, MCF-10A, were tested in this study. We found that UP exerted a potent cytotoxicity against all breast carcinoma cell lines in a dose- and time-dependent manner. In contrast, UP showed limited toxicity to MCF-10A cells, indicating UP's cytotoxic effect is selective for malignant cells. UP's cytotoxic effect was due to apoptosis, as confirmed by positive TUNEL signals, annexin V-binding, caspase 9 activation and PARP cleavage. Notably, UP-induced apoptosis was blocked by the pan-caspase inhibitor z-VAD.fmk, further indicating the involvement of caspase activity. Moreover, UP caused a marked decrease of the levels of antiapoptotic BCL-X(L), Survivin and XIAP while enhancing the levels of proapoptotic BIK, BIM, MCL-1S and NOXA, consequently favoring induction of apoptosis. Additionally, we found that cells with functional p53 (MCF-7, T47D) or mutant p53 (BT-20, MDA-MB-231) were both susceptible to UP's cytotoxicity. Importantly, UP was able to induce apoptosis in MCF-7 cells with p53 knockdown by RNA interference, confirming the dispensability of p53 in UP-induced apoptosis. Overall, our results establish that UP induces p53-independent apoptosis in breast carcinoma cells with no marked toxicity to nonmalignant cells, raising the possibility of its use as a new chemotherapeutic drug for breast cancer irrespective of p53 status.
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PMID:Undecylprodigiosin selectively induces apoptosis in human breast carcinoma cells independent of p53. 1788 Oct 28

Wogonin is a plant monoflavonoid which has been reported to inhibit cell growth and/or induce apoptosis in various tumors. Herein, we investigated the in vitro and in vivo anticancer effects and associated mechanisms of wogonin in human breast cancer. Effects of wogonin were examined in estrogen receptor (ER)-positive and -negative human breast cancer cells in culture for proliferation, cell cycle progression, and apoptosis. The in vivo effect of oral wogonin was examined on tumor xenograft growth in athymic nude mice. The molecular changes associated with the biological effects of wogonin were analyzed by immunoblotting. Cell growth was attenuated by wogonin (50-200 microM), independently of its ER status, in a time- and concentration-dependent manner. Apoptosis was enhanced and accompanied by upregulation of PARP and Caspase 3 cleavages as well as proapoptotic Bax protein. Akt activity was suppressed and reduced phosphorylation of its substrates, GSK-3beta and p27, was observed. Suppression of Cyclin D1 expression suggested the downregulation of the Akt-mediated canonical Wnt signaling pathway. ER expression was downregulated in ER-positive cells, while c-ErbB2 expression and its activity were suppressed in ER-negative SK-BR-3 cells. Wogonin feeding to mice showed inhibition of tumor growth of T47D and MDA-MB-231 xenografts by up to 88% without any toxicity after 4 weeks of treatment. As wogonin was effective both in vitro and in vivo, our novel findings open the possibility of wogonin as an effective therapeutic and/or chemopreventive agent against both ER-positive and -negative breast cancers, particularly against the more aggressive and hormonal therapy-resistant ER-negative types.
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PMID:Anticancer effects of wogonin in both estrogen receptor-positive and -negative human breast cancer cell lines in vitro and in nude mice xenografts. 1795 84

Currently, there is no effective therapy for estrogen independent breast cancer. MDA-MB-231 is an estrogen receptor negative highly invasive human breast cancer cell line and has been used as a relevant model system to evaluate drugs with chemopreventive potential against highly invasive breast cancer phenotypes. Epidemiological studies though inconclusive have shown that consumption of Green Tea Polyphenols (GTP) reduces the incidence and progression of breast cancer. Green tea is an important source of antioxidants that may be useful for chemoprevention of cancer. Recently published preclinical study from our lab suggested that GTP and EGCG treatment inhibit proliferation and induce apoptosis of MDA-MB-231. In this study, we have evaluated apoptotic and anti-invasive activity of green tea polyphenols (GTP) and its principal constituent Epigallocatechin gallate (EGCG) in MDA-MB-231 human breast cancer cell line. In in vitro human breast cancer model, EGCG and GTP induced apoptosis and significantly decreased invasion of breast cancer cells. Western blotting of MDA-MB-231 cell lysates from EGCG and GTP treated and untreated control revealed an increase in bax, reduction in bcl2 and PARP cleavage. Quantitative fluorescence labeling resulted in a 24-28% reduction in invasion through matrigel by EGCG and 15-23% reduction by GTP in a dose dependent manner. Focussed microarray analysis and reverse transcriptase polymerase chain reaction and zymogram analysis revealed inhibition of MMP-9 expression by polyphenol treatment. Furthermore, AKT was found to be inhibited both at the RNA and protein level by polyphenol treatment. Moreover EGCG and GTP decreased AKT phosphorylation as found out by Western blotting for Phospho-AKT (Ser-473). beta-catenin level was found to be decreased both in cytoplasm and nucleus. For the first time we report the connection of beta-catenin and AKT modulation by GTP and EGCG as a possible mechanism for the induction of apoptosis in human breast cancer cells and also inhibition in their invasive capacity.
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PMID:Green tea polyphenol and epigallocatechin gallate induce apoptosis and inhibit invasion in human breast cancer cells. 1805 61

The marked clinical anticancer activity of the paclitaxel (PTX) and gemcitabine (GEM) combination has suggested that the two drugs may interact more than additively. We have analyzed the in vitro growth and molecular interactions of the two chemotherapy drugs in a panel of human breast cancer cells. We evaluated cell viability in four breast cancer cell lines (i.e., MCF-7, MDA-MB-231, MDA-MB-468, and SKBR3) that were treated with PTX and GEM combined either simultaneously (PTX + GEM) or sequentially (PTX --> GEM; GEM --> PTX). PTX-GEM interactions at the cellular level were assessed mathematically employing both the isobologram analysis (Berenbaum) and the combination index (Chou-Talalay) method. PTX-GEM molecular interactions on the apoptotic markers PARP, Bcl-2 and Bax were analyzed by immunoblotting procedures. Apoptosis was detected using a DNA ladder assay. We observed significant synergistic growth inhibitory interactions when PTX was administered before GEM. Additive interactions were observed when both the simultaneous regimen and the GEM followed by PTX regimen were used. DNA ladder and Western blotting results in the PTX followed by GEM sequence revealed a significant increase in the apoptotic cell death of breast cancer cells related to the Bax/Bcl-2 apoptotic pathway. In summary, the occurrence of clinically relevant synergism between PTX and GEM suggests a sequence-dependent nature in human breast cancer cells. This synergistic interaction on the PTXright curved arrow GEM schedule appears to be related to an increase in the Bcl-2-related mitochondrial apoptotic pathway. The synergism that we have observed may explain the favorable clinical responses that have been achieved in clinical studies, in which patients are administered PTX first, and then GEM.
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PMID:Sequence-dependent synergism and antagonism between paclitaxel and gemcitabine in breast cancer cells: the importance of scheduling. 1809 49

Obesity is a risk factor for postmenopausal breast cancer. Adiponectin/Acrp30 is lower in obese individuals and may be negatively regulating breast cancer growth. Here we determined that five breast cancer cell lines, MDA-MB-231, MDA-MB-361, MCF-7, T47D, and SK-BR-3, expressed one or both of the Acrp30 receptors. In addition, we found that the addition of Acrp30 to MCF-7, T47D, and SK-BR-3 cell lines inhibited growth. Oestrogen receptor (ER) positive MCF-7 and T47D cells were inhibited at lower Acrp30 concentrations than ER-negative SK-BR-3 cells. Growth inhibition may be related to apoptosis since PARP cleavage was increased by Acrp30 in the ER-positive cell lines. To investigate the role of ER in the response of breast cancer cells to Acrp30, we established the MDA-ERalpha7 cell line by insertion of ER-alpha into ER-alpha-negative MDA-MB-231 cells. This line readily formed tumours in athymic mice and was responsive to oestradiol in vivo. In vitro, MDA-ERalpha7 cells were growth inhibited by globular Acrp30 while the parental cells were not. This inhibition appeared to be due to blockage of JNK2 signalling. These results provide information on how obesity may influence breast cancer cell proliferation and establish a new model to examine interactions between ER and Acrp30.
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PMID:Effects of adiponectin on breast cancer cell growth and signaling. 1818 89

Oncolytic measles virus strains have activity against multiple tumor types and are currently in phase I clinical testing. Induction of the heat shock protein 70 (HSP70) constitutes one of the earliest changes in cellular gene expression following infection with RNA viruses including measles virus, and HSP70 upregulation induced by heat shock has been shown to result in increased measles virus cytotoxicity. HSP90 inhibitors such as geldanamycin (GA) or 17-allylaminogeldanamycin result in pharmacologic upregulation of HSP70 and they are currently in clinical testing as cancer therapeutics. We therefore investigated the hypothesis that heat shock protein inhibitors could augment the measles virus-induced cytopathic effect. We tested the combination of a measles virus derivative expressing soluble human carcinoembryonic antigen (MV-CEA) and GA in MDA-MB-231 (breast), SKOV3.IP (ovarian) and TE671 (rhabdomyosarcoma) cancer cell lines. Optimal synergy was accomplished when GA treatment was initiated 6-24 h following MV infection. Western immunoblotting confirmed HSP70 upregulation in combination-treated cells. Combination treatment resulted in statistically significant increase in syncytia formation as compared to MV-CEA infection alone. Clonogenic assays demonstrated significant decrease in tumor colony formation in MV-CEA/GA combination-treated cells. In addition there was increase in apoptosis by 4,6-diamidino-2-phenylindole staining. Western immunoblotting for caspase-9, caspase-8, caspase-3 and poly(ADP-ribose) polymerase (PARP) demonstrated increase in cleaved caspase-8 and PARP. The pan-caspase inhibitor Z-VAD-FMK and caspase-8 inhibitor Z-IETD-FMK, but not the caspase-9 inhibitor Z-IEHD-FMK, protected tumor cells from MV-CEA/GA-induced PARP activation, indicating that apoptosis in combination-treated cells occurs mainly via the extrinsic caspase pathway. Treatment of normal cells, such as normal human fibroblasts, however, with the MV-CEA/GA combination, did not result in cytopathic effect, indicating that GA did not alter the MV-CEA specificity for tumor cells. One-step viral growth curves, western immunoblotting for MV-N protein expression, QRT-PCR quantitation of MV-genome copy number and CEA levels showed comparable proliferation of MV-CEA in GA-treated vs -untreated tumor cells. Rho activation assays and western blot for total RhoA, a GTPase associated with the actin cytoskeleton, demonstrated decrease in RhoA activation in combination-treated cells, a change previously shown to be associated with increase in paramyxovirus-induced cell-cell fusion. The enhanced cytopathic effect resulting from measles virus/GA combination supports the translational potential of this approach in the treatment of cancer.
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PMID:Heat shock protein inhibitors increase the efficacy of measles virotherapy. 1835 18


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