Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P42574 (caspase-3)
 45,978 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma in children. Highly malignant, RMS frequently fails to respond to conventional aggressive multimodal radiation, surgery, and chemotherapy treatment protocols that also cause significant sequelae in the growing child. Other tumors of mesenchymal origin, such as locally aggressive fibromatoses and desmoid tumors, have been successfully treated with a selective estrogen receptor (ER) modulator, tamoxifen. In an effort to identify new targets for RMS therapy, our group investigated the previously uncharacterized ER pathway in RMS cell culture and primary tumors. We detected ER isoform beta (ER beta), but not isoform alpha, RNA, and protein in five RMS cell lines. Immunohistochemical staining of primary RMS tumor sections confirmed high levels of ER beta but not ER alpha protein. RMS cell growth was dramatically inhibited in steroid-free conditions, and this growth inhibition was rescued with 17-beta-estradiol (E2) supplementation. Exposure of RMS cells to 4'OH-tamoxifen (4OHT) decreased cell viability and inhibited colony formation as detected by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and colony-forming assays. 4OHT also induced apoptotic signaling in RMS cells as detected by cleavage of caspase-3 and poly(ADP)ribose polymerase. This effect increased 3- to 8-fold in steroid-deprived conditions but was rescued by supplementation with E2. Immunofluorescence studies detected a change in the subcellular localization of ER beta in response to 4OHT. Together, these data suggest an active ER beta-mediated signal transduction pathway in RMS. The ability of 4OHT to induce apoptotic signaling and disrupt estradiol-mediated proliferation provides a rationale to explore a role for selective ER modulators in the treatment of RMS.
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PMID:The estrogen receptor pathway in rhabdomyosarcoma: a role for estrogen receptor-beta in proliferation and response to the antiestrogen 4'OH-tamoxifen. 1845 Nov 76

A pharmacological dose (2.5-10 microM) of 17alpha-estradiol (17alpha-E(2)) exerted a cytotoxic effect on human leukemias Jurkat T and U937 cells, which was not suppressed by the estrogen receptor (ER) antagonist ICI 182,780. Along with cytotoxicity in Jurkat T cells, several apoptotic events including mitochondrial cytochrome c release, activation of caspase-9, -3, and -8, PARP degradation, and DNA fragmentation were induced. The cytotoxicity of 17alpha-E(2) was not blocked by the anti-Fas neutralizing antibody ZB-4. While undergoing apoptosis, there was a remarkable accumulation of G(2)/M cells with the upregulatoin of cdc2 kinase activity, which was reflected in the Thr56 phosphorylation of Bcl-2. Dephosphorylation at Tyr15 and phosphorylation at Thr161 of cdc2, and significant increase in the cyclin B1 level were underlying factors for the cdc2 kinase activation. Whereas the 17alpha-E(2)-induced apoptosis was completely abrogated by overexpression of Bcl-2 or by pretreatment with the pan-caspase inhibitor z-VAD-fmk, the accumulation of G(2)/M cells significantly increased. The caspase-8 inhibitor z-IETD-fmk failed to influence 17alpha-E(2)-mediated caspase-9 activation, but it markedly reduced caspase-3 activation and PARP degradation with the suppression of apoptosis, indicating the contribution of caspase-8; not as an upstream event of the mitochondrial cytochrome c release, but to caspase-3 activation. In the presence of hydroxyurea, which blocked the cell cycle progression at the G(1)/S boundary, 17alpha-E(2) failed to induce the G(2)/M arrest as well as apoptosis. These results demonstrate that the cytotoxicity of 17alpha-E(2) toward Jurkat T cells is attributable to apoptosis mainly induced in G(2)/M-arrested cells, in an ER-independent manner, via a mitochondria-dependent caspase pathway regulated by Bcl-2.
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PMID:17Alpha-estradiol arrests cell cycle progression at G2/M and induces apoptotic cell death in human acute leukemia Jurkat T cells. 1860 76

Raloxifene is a nonsteroidal benzothiophene that has also been classified as a selective estrogen receptor modulator (SERM) on the basis of studies in which it produced both estrogen-agonistic effects on bone and lipid metabolism and estrogen-antagonistic effects on uterine endometrium and breast tissue. We investigated apoptotic cell death and the apoptotic pathway in human endometrial carcinoma cells (Ishikawa cells) expressing estrogen receptor treated with raloxifene. Cell viability was significantly decreased in Ishikawa cells treated with raloxifene at 20 microM and higher levels. Raloxifene at 20 microM induced 54% inhibition of cell viability after 48 h treatment. Apoptotic parameters were analyzed for determination of apoptotic pathway in Ishikawa cells treated with 20 microM or 40 microM raloxifene for 48 h. The numbers of apoptotic cells were significantly increased in cells treated with raloxifene as compared with control cells. Activities of caspase-3,-8, and-9 were significantly elevated in Ishikawa cells treated with raloxifene. A significant decrease in mitochondrial membrane potential was observed in this treatment. In addition, the levels of cytosolic cytochrome c were significantly elevated in raloxifene-treated cells. Expression of Bid was detected in both control and raloxifene-treated cells, but Bid cleavage was not observed. In caspase inhibitor experiments, cell viability was significantly increased by the caspase-9 inhibitor z-LEHD-fmk and by the caspase-3 inhibitor z-DEVD-fmk. However, cell viability was unaffected by addition of the caspase-8 inhibitor z-IETD-fmk. Thus, raloxifene induced mitochondria-mediated apoptosis in endometrial cancer cells but not via the Bid-mitochondria pathway. It is possibly that raloxifene may be useful as an adjuvant to current chemotherapies for endometrial cancer and possibly is useful as a chemopreventive agent.
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PMID:Raloxifene, a selective estrogen receptor modulator, induces mitochondria-mediated apoptosis in human endometrial carcinoma cells. 1880 38

Phytoestrogens are polyphenolic non-steroidal plant compounds with estrogen-like biological activity. The phytoestrogen puerarin, the main isoflavone glycoside found in the root of Pueraria lobata, has been used for various medicinal purposes in traditional Chinese medicines for thousands of years. Recent studies have indicated that the estrogen receptor (ER), through interaction with p85, regulates phosphoinositide 3-kinase (PI3K) activity, revealing a physiologic, non-nuclear function of ER that may be relevant in cytoprotection. In this study, we demonstrate that the phytoestrogen puerarin inhibits tert-butyl hydroperoxide (t-BHP)-induced oxidative injury via an ER-dependent Gbeta1/PI3K/Akt and heme oxygenase-1 (HO-1) pathway. Pretreatment of Hepa1c1c7 and HepG2 cells with puerarin significantly reduced t-BHP-induced caspase-3 activation and subsequent cell death. Also, puerarin up-regulated HO-1 expression and this expression conferred cytoprotection against oxidative injury induced by t-BHP. Moreover, puerarin induced Nrf2 nuclear translocation, which is upstream of puerarin-induced HO-1 expression, and PI3K activation, a pathway that is involved in induced Nrf2 nuclear translocation, HO-1 expression and cytoprotection. Puerarin-induced up-regulation of HO-1 and cytoprotection against t-BHP were abolished by silencing Nrf2 expression with specific siRNA. Also, puerarin-mediated increases in PI3K activation and HO-1 induction were reversed by co-treatment with ICI 182,780 and pertussis toxin. Taken together, these results suggest that puerarin augments cellular antioxidant defense capacity through ER-dependent HO-1 induction via the Gbeta1/PI3K/Akt-Nrf2 signaling pathway, thereby protecting cells from oxidative stress.
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PMID:Mechanism of phytoestrogen puerarin-mediated cytoprotection following oxidative injury: estrogen receptor-dependent up-regulation of PI3K/Akt and HO-1. 1884 76

Diets high in soy are neuroprotective in experimental stroke. This protective effect is hypothesized to be mediated by phytoestrogens contained in soy, because some of these compounds have neuroprotective effects in in vitro models of cell death. We tested the ability of the soy phytoestrogens genistein, daidzein, and the daidzein metabolite equol to protect embryonic rat primary cortical neurons from ischemic-like injury in vitro at doses typical of circulating concentrations in human populations (0.1-1 microM). All three phytoestrogens inhibited lactate dehydrogenase (LDH) release from cells exposed to glutamate toxicity or the calcium-ATPase inhibitor, thapsigargin. In cells exposed to hypoxia or oxygen-glucose deprivation (OGD), pretreatment with the phytoestrogens inhibited cell death in an estrogen receptor (ER) dependent manner. Although OGD results in multiple modes of cell death, examination of alpha-spectrin cleavage and caspase-3 activation revealed that the phytoestrogens were able to inhibit apoptotic cell death in this model. In addition, blockade of phosphoinositide 3-kinase prevented the protective effects of genistein and daidzein, and blockade of mitogen-activated protein kinase prevented genistein-dependent neuroprotection. These results suggest that pretreatment with dietary levels of soy phytoestrogens can mimic neuroprotective effects observed with estrogen and appear to use the same ER-kinase pathways to inhibit apoptotic cell death.
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PMID:Soy phytoestrogens are neuroprotective against stroke-like injury in vitro. 1897 94

Activation of aryl hydrocarbon receptors (AhRs) induces neuronal damage, but the mechanism by which this occurs is largely unknown. This study evaluated the effects of an AhR agonist, beta-naphthoflavone, on apoptotic pathways in mouse primary neuronal cell cultures. beta-Naphthoflavone (0.1-100 micronhanced caspase-3 activity and lactate dehydrogenase (LDH) release in neocortical and hippocampal cells. These data were supported at the cellular level with Hoechst 33342 and calcein AM staining. alpha-Naphthoflavone inhibited the action of beta-naphthoflavone, thus confirming specific activation of AhRs. A high-affinity estrogen receptor (ER) antagonist, ICI 182,780, and a selective estrogen receptor modulator (SERM), tamoxifen, enhanced beta-naphthoflavone-mediated apoptosis. Another SERM, raloxifene, and an ERalpha antagonist, methyl-piperidino-pyrazole, did not affect beta-naphthoflavone-induced caspase-3 activity. However, they inhibited beta-naphthoflavone-induced LDH release at a late hour of treatment, thus suggesting delayed control of AhR-mediated neuronal cell death. The apoptotic effects of beta-naphthoflavone were accompanied by increased levels of AhRs, and these receptors colocalized with ERbeta as demonstrated by confocal microscopy. These data strongly support apoptotic effects of AhR activation in neocortical and hippocampal tissues. Moreover, this study provides evidence for direct interaction of the AhR-mediated apoptotic pathway with estrogen receptor signaling, which provides insight into new strategies to treat or prevent AhR-mediated neurotoxicity.
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PMID:Aryl hydrocarbon receptor-mediated apoptosis of neuronal cells: a possible interaction with estrogen receptor signaling. 1902 52

Experimental evidence supports a protective role of estrogen in the brain. According to the fact that Alzheimer's disease (AD) is more common in postmenopausal women, estrogen treatment has been proposed. However, there is no general consensus on the beneficial effect of estrogen or selective estrogen receptor modulators in preventing or treating AD. It has to be said that several factors may markedly affect the efficacy of the treatment. A few years ago, the seladin-1 gene (for selective Alzheimer's disease indicator-1) has been isolated and found to be down-regulated in brain regions affected by AD. Seladin-1 has been found to be identical to the gene encoding the enzyme 3-beta-hydroxysterol delta-24-reductase, involved in the cholesterol biosynthetic pathway, which confers protection against beta-amyloid-mediated toxicity and from oxidative stress, and is an effective inhibitor of caspase-3 activity, a key mediator of apoptosis. Interestingly, we found earlier that the expression of this gene is up-regulated by estrogen. Furthermore, our very recent data support the hypothesis that seladin-1 is a mediator of the neuroprotective effects of estrogen. This review will summarize the current knowledge regarding the neuroprotective effects of seladin-1 and the relationship between this protein and estrogen.
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PMID:Estrogen receptor-mediated neuroprotection: The role of the Alzheimer's disease-related gene seladin-1. 1904 24

Honokiol is a naturally occurring neolignan abundant in Magnoliae Cortex and has showed anti-proliferative and pro-apoptotic effects in a wide range of human cancer cells. However, the molecular mechanisms on the anti-proliferative activity in cancer cells have been poorly elucidated. In this study, we evaluated the growth inhibitory activity of honokiol in cultured estrogen receptor (ER)-negative MDA-MB-231 human breast cancer cells. Honokiol exerted anti-proliferative activity with the cell cycle arrest at the G0/G1 phase and sequential induction of apoptotic cell death in a concentration-dependent manner. The honokiol-induced cell cycle arrest was well correlated with the suppressive expression of CDK4, cyclin D1, CDK2, cyclin E, c-Myc, and phosphorylated retinoblastoma protein (pRb) at Ser780. Apoptosis caused by honokiol was also concomitant with the cleavage of caspases (caspase-3, -8, and -9) and Bid along with the suppressive expression of Bcl-2, but it was independent on the expression of Bax and p53. In addition, honokiol-treated cells exhibited the cleavage of poly (ADP-ribose) polymerase (PARP) and DNA fragmentation. In the analysis of signal transduction pathway, honokiol down-regulated the expression and phosphorylation of c-Src, epidermal growth factor receptor (EGFR), and Akt, and consequently led to the inactivation of mTOR and its downstream signal molecules including 4E-binding protein (4E-BP) and p70 S6 kinase. These findings suggest that honokiol-mediated inhibitory activity of cancer cell growth might be related with the cell cycle arrest and induction of apoptosis via modulating signal transduction pathways.
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PMID:Down-regulation of c-Src/EGFR-mediated signaling activation is involved in the honokiol-induced cell cycle arrest and apoptosis in MDA-MB-231 human breast cancer cells. 1913 78

The modulatory influence of the phytoestrogen biochanin A, an isoflavinoid found in red clover (Trifolium pratense), on the differentiation and proliferation of mammary epithelial cells and the expression of estrogen receptor-alpha (ER-alpha) in female prepubertal Sprague-Dawley rat mammary glands was examined, for which there have been no reports to date. Biochanin A (500 microg/g bw) was injected subcutaneously on days 16, 18 and 20 post-partum. The mammary gland was dissected out and terminal end buds, terminal ducts and lobules were counted. ER-alpha, Bcl2, Bax and caspase-3 expression were determined by immunohistochemistry. Estradiol benzoate (EB) (500 ng/g bw) and dimethyl sulphoxide (DMSO) were used as the reference and vehicle, respectively. The results showed a significant enhancement of differentiation at post-natal day (PND) 21 as well as at PND 50 in the mammary glands. There was a significant decrease of ER-alpha expression at PND 21 and an increased expression of the same at PND 50, whereas increased proliferation at PND 21 and increased apoptosis at PND 50 in the mammary glands were observed in biochanin A treated animals. The mode and magnitude of the effect of biochanin A was almost similar to that of EB. These findings suggested that prepubertal exposure to biochanin A modulated the regulatory processes and in turn enhanced the differentiation and development of mammary glands in female rats. These observations may have significance in human health.
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PMID:Modulatory influence of prepubertal biochanin A exposure on mammary gland differentiation and expression of estrogen receptor-alpha and apoptotic proteins. 1917 Jan 58

Hepatic damage occurs in males and ovariectomized (OVX), not in proestrus (PE), females following trauma-hemorrhage (T-H). The mechanism responsible for hepatoprotection remains unknown. We hypothesized protection in PE is a result of enhanced heme oxygenase-1 (HO-1)-derived down-regulation of liver inflammatory responses. PE and OVX rats underwent T-H (midline laparotomy, 60% blood loss). PE rats received vehicle (Veh; saline), HO-1 inhibitor chromium mesoporphyrin IX chloride (CrMP; 2.5 mg/kg), zinc protoporphyrin IX (ZnPP; 25 mg/kg), or Akt/PI-3K inhibitor Wortmannin (Wort; 1 mg/kg) 30 min prior to resuscitation or sham operation i.p. OVX rats received Veh or 17beta-estradiol (E2; 1 mg/kg) 30 min before hemorrhage. Rats were killed 2 h thereafter. Following T-H, left ventricular performance was maintained in PE and E2 OVX rats but was depressed in OVX and CrMP-, ZnPP-, and Wort-treated PE rats; liver damage was not evident in PE rats, and CrMP, ZnPP, and Wort abrogated protection; liver HO-1, p38 MAPK, Akt/PI3K, and Bcl-2 expression increased in PE and E2 OVX rats, which was abrogated by CrMP, ZnPP, and Wort, and liver ICAM-1, caspase-3, phospho-IkappaB-alpha, and NF-kappaB expression increased in OVX and CrMP-, ZnPP-, and Wort-PE rats; liver myeloperoxidase, NF-kappaB DNA-binding activity, TNF-alpha, IL-6, plasma proinflammatory cytokines, and cytokine-induced neutrophil chemoattractants increased in OVX and CrMP-, ZnPP-, and Wort-PE rats; and plasma estradiol levels and hepatic estrogen receptor-alpha and -beta expression decreased in OVX but were unaltered by CrMP, ZnPP, and Wort. Thus, enhanced HO-1 in PE and E2 OVX females modulates inflammatory responses and protects liver following T-H.
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PMID:Mechanism of hepatoprotection in proestrus female rats following trauma-hemorrhage: heme oxygenase-1-derived normalization of hepatic inflammatory responses. 1924 65


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