Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P10415 (Bcl-2)
 33,771 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Isoflavone genistein may have beneficial effects on vascular function, but the mechanism is unclear. Here, we investigated whether genistein protects vascular endothelial cells against apoptosis induced by tumor necrosis factor-alpha. We show that genistein significantly inhibited TNF-alpha-induced apoptosis in human aortic endothelial cells as determined by caspase-3 activation, 7-amino actinomycin D staining, in situ apoptotic cell detection and DNA laddering. The anti-apoptotic effect of genistein was associated with an enhanced expression of Bcl-2 protein and its promoter activity. Inhibition of extracellular signal-regulated kinase 1/2, protein kinase A, or estrogen receptors had no effect on the cytoprotective effect of genistein. However, inhibition of p38 mitogen-activated protein kinase (p38) completely abolished this genistein effect. Accordingly, stimulation of HAECs with genistein resulted in rapid activation of p38beta, but not p38alpha. These findings provide the evidence that genistein acts as a survival factor for vascular ECs to protect cells against apoptosis via activation of p38beta. Preservation of the functional integrity of the endothelial monolayer may represent an important mechanism by which genistein exerts its vasculoprotective effect.
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PMID:Isoflavone genistein protects human vascular endothelial cells against tumor necrosis factor-alpha-induced apoptosis through the p38beta mitogen-activated protein kinase. 1908 97

This study is the first to investigate the anticancer effect of dehydrocostuslactone [DHE (3aS,6aR,9aR,9bS)-decahydro-3,6,9-tris(methylene) azuleno[4,5-b]furan-2(3H)-one)], a medicinal plant-derived sesquiterpene lactone, on hepatocellular carcinoma. Our results showed that DHE inhibits the proliferation of HepG2 and PLC/PRF/5 cells by inducing apoptosis. DHE induces up-regulation of Bax and Bak, down-regulation of Bcl-2 and Bcl-XL, and nuclear relocation of the mitochondrial factors apoptosis-inducing factor (AIF) and endonuclease G (Endo G). DHE triggered endoplasmic reticulum (ER) stress, as indicated by changes in cytosol-calcium levels, double-stranded RNA-activated protein kinase-like endoplasmic reticulum kinase phosphorylation, inositol-requiring protein 1 (IRE1) and CHOP/GADD153 up-regulation, X-box transcription factor-1 mRNA splicing, and caspase-4 activation. Enhancement of ER stress by DHE is through p38 and extracellular signal-regulated kinase 1/2-dependent manners and subsequently causes c-Jun NH(2)-terminal kinase activation, resulting in AIF and Endo G nuclear relocation. Both of IRE1 small interfering RNA transfection and 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid-acetoxymethyl ester pretreatment inhibit DHE-mediated apoptosis, supporting the hypothesis that DHE induces cell death through ER stress. It is noteworthy that animal studies have revealed a dramatic 50% reduction in tumor volume after 45 days of treatment. This study demonstrates that DHE may be a novel anticancer agent for the treatment of liver cancer.
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PMID:Dehydrocostuslactone, a medicinal plant-derived sesquiterpene lactone, induces apoptosis coupled to endoplasmic reticulum stress in liver cancer cells. 1918 81

Melanoma is a particularly aggressive tumor type that exhibits a high level of resistance to apoptosis. The serine/threonine kinase B-RAF is mutated in 50% to 70% of melanomas and protects melanoma cells from anoikis, a form of apoptosis induced by lack of adhesion or adhesion to an inappropriate matrix. Mutant B-RAF down-regulates two BH3-only proapoptotic proteins, Bim(EL) and Bad. BH3-only proteins act, at least in part, by sequestering prosurvival Bcl-2 family proteins and preventing them from inhibiting the mitochondrial apoptotic pathway. Several Bcl-2 proteins are up-regulated in melanoma; however, the mechanisms of up-regulation and their role in melanoma resistance to anoikis remain unclear. Using RNA interference, we show that depletion of Mcl-1 renders mutant B-RAF melanoma cells sensitive to anoikis. By contrast, minor effects were observed following depletion of either Bcl-2 or Bcl-(XL). Mcl-1 expression is enhanced in melanoma cell lines compared with melanocytes and up-regulated by the B-RAF-MEK-extracellular signal-regulated kinase 1/2 pathway through control of Mcl-1 protein turnover. Similar to B-RAF knockdown cells, adhesion to fibronectin protected Mcl-1 knockdown cells from apoptosis. Finally, expression of Bad, which does not sequester Mcl-1, further augmented apoptosis in nonadherent Mcl-1 knockdown cells. Together, these data support the notion that BH3 mimetic compounds that target Mcl-1 may be effective for the treatment of melanoma in combinatorial strategies with agents that disrupt fibronectin-integrin signaling.
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PMID:Mcl-1 is required for melanoma cell resistance to anoikis. 1937 83

Glutamate-induced neurotoxicity consequent to N-methyl-D-aspartic acid (NMDA) and 2-amino-3-(3-hydroxy-5-methyl-isoxazol-4-yl) propionic acid (AMPA) receptor activation underlies the pathogenesis of a wide range of central nervous system disorders, including brain ischemia. Prevention of ischemia/reperfusion (I/R)-induced neuronal injury has long been regarded as an effective therapeutic strategy for ischemia. Human tissue kallikrein (TK) gene transfer has been shown to protect neurons against cerebral I/R-induced apoptosis and oxidative stress, via activation of the brandykinin B2 receptor (B2R). However, little is known about the role of TK on glutamate-induced neurotoxicity. Here we report that pretreatment of cultured cortical neurons with TK largely prevented glutamate-induced morphological changes and cell death. We found that TK pretreatment alleviated glutamate-induced oxidative stress by inhibiting neuronal nitric oxide synthase (nNOS) activity, thereby reducing the generation of nitric oxide (NO) and reactive oxygen species (ROS). Blockage of NMDA and AMPA receptors by their specific antagonists MK801 and CNQX had effects similar to those of TK administration. Furthermore, we found that the extracellular signal-regulated kinase 1/2 cascade (ERK1/2), particularly ERK1, and nuclear factor-kappaB (NF-kappaB) were involved in TK neuroprotection against glutamate-induced neurotoxicity. TK pretreatment activated ERK1 and NF-kappaB, leading to enhanced expression of brain-derived neurotrophic factor (BDNF) mRNA and antiapoptotic gene Bcl-2 protein. Collectively, these findings demonstrate that TK attenuates glutamate-induced apoptosis through an intracellular signaling pathway including activation of B2R, ERK1/2, and NF-kappaB and up-regulation of BDNF and Bcl-2 expression. Thus, TK represents a promising therapeutic strategy for ischemic stroke.
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PMID:Tissue kallikrein alleviates glutamate-induced neurotoxicity by activating ERK1. 1959 50

New cytotoxic agents are urgently needed for the treatment of advanced ovarian cancer because of the poor long-term response of this disease to conventional chemotherapy. Curcumin, obtained from the rhizome of Curcuma longa, has potent anticancer activity; however, the mechanism of curcumin-induced cytotoxicity in ovarian cancer cells remains a mystery. In this study we show that curcumin exhibited time- and dose-dependent cytotoxicity against monolayer cultures of ovarian carcinoma cell lines with differing p53 status (wild-type p53: HEY, OVCA429; mutant p53: OCC1; null p53: SKOV3). In addition, p53 knockdown or p53 inhibition did not diminish curcumin killing of HEY cells, confirming p53-independent cytotoxicity. Curcumin also killed OVCA429, and SKOV3 cells grown as multicellular spheroids. Nuclear condensation and fragmentation, as well as DNA fragmentation and poly (ADP-ribose) polymerase-1 cleavage in curcumin-treated HEY cells, indicated cell death by apoptosis. Procaspase-3, procaspase-8, and procaspase-9 cleavage, in addition to cytochrome c release and Bid cleavage into truncated Bid, revealed that curcumin activated both the extrinsic and intrinsic pathways of apoptosis. Bax expression was unchanged but Bcl-2, survivin, phosphorylated Akt (on serine 473), and total Akt were downregulated in curcumin-treated HEY cells. Curcumin also activated p38 mitogen-activated protein kinase (MAPK) without altering extracellular signal-regulated kinase 1/2 activity. We conclude that p53-independent curcumin-induced apoptosis in ovarian carcinoma cells involves p38 MAPK activation, ablation of prosurvival Akt signaling, and reduced expression of the antiapoptotic proteins Bcl-2 and survivin. These data provide a mechanistic rationale for the potential use of curcumin in the treatment of ovarian cancer.
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PMID:Curcumin-induced apoptosis in ovarian carcinoma cells is p53-independent and involves p38 mitogen-activated protein kinase activation and downregulation of Bcl-2 and survivin expression and Akt signaling. 1967 5

The morphological and functional integrity of the microcirculation is compromised in many cardiovascular diseases such as hypertension, diabetes, stroke, and sepsis. Angiotensin converting enzyme inhibitors (ACEi), which are known to favor bradykinin (BK) bioactivity by reducing its metabolism, may have a positive impact on preventing the microvascular structural rarefaction that occurs in these diseases. Our study was designed to test the hypothesis that BK, via B2 receptors (B2R), protects the viability of the microvascular endothelium exposed to the necrotic and apoptotic cell death inducers H(2)O(2) and LPS independently of hemodynamics. Expression (RT-PCR and radioligand binding) and functional (calcium mobilization with fura-2AM, and p42/p44MAPK and Akt phosphorylation assays) experiments revealed the presence of functional B2R in pig cerebral microvascular endothelial cells (pCMVEC). In vitro results showed that the cytocidal effects of H(2)O(2) and LPS on pCMVEC were significantly decreased by a BK pretreatment (MTT and crystal violet tests, annexin-V staining/FACS analysis), which was countered by the B2R antagonist HOE 140. BK treatment coincided with enhanced expression of the cytoprotective proteins COX-2, Bcl-2, and (Cu/Zn)SOD. Ex vivo assays on rat brain explants showed that BK impeded (by approximately 40%) H(2)O(2)-induced microvascular degeneration (lectin-FITC staining). The present study proposes a novel role for BK in microvascular endothelial protection, which may be pertinent to the complex mechanism of action of ACEi explaining their long-term beneficial effects in maintaining vascular integrity.
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PMID:Bradykinin protects against brain microvascular endothelial cell death induced by pathophysiological stimuli. 1978 24

The function of the epidermal growth factor receptor (EGFR) is dysregulated in various types of malignancy as a result of gene amplification, mutations, or abnormally increased ligand production. Therefore, the tyrosine kinase activity of the EGFR is a promising therapeutic target. EGFR tyrosine kinase inhibitors, such as gefitinib (Iressa), show evident anticancer effects in patients with non-small cell lung cancer. The induction of apoptosis has been considered to be the major mechanism for these gefitinib-mediated anticancer effects. Lung cancer cells harboring mutant EGFRs become dependent on them for their survival and, consequently, undergo apoptosis following the inhibition of EGFR tyrosine kinase by gefitinib. Gefitinib has been shown to inhibit cell survival and growth signaling pathways such as the extracellular signal-regulated kinase 1/2 pathway and the Akt pathway, as a consequence of the inactivation of EGFR. However, the precise downstream signaling molecules of extracellular signal-regulated kinase 1/2 and Akt have not yet been elucidated. In this minireview we have highlighted the effect of tyrosine kinase inhibitors on members of the Bcl-2 family of proteins, which are downstream signaling molecules and serve as the determinants that control apoptosis. We also discuss tyrosine kinase inhibitor-induced apoptosis via c-Jun NH(2)-terminal kinase and p38 mitogen-activated protein kinase.
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PMID:EGF receptor in relation to tumor development: molecular basis of responsiveness of cancer cells to EGFR-targeting tyrosine kinase inhibitors. 1992 67

This study is the first to investigate the anticancer effect of 6-dehydrogingerdione (DGE), an active constituent of dietary ginger, in human breast cancer MDA-MB-231 and MCF-7 cells. DGE exhibited effective cell growth inhibition by inducing cancer cells to undergo G2/M phase arrest and apoptosis. Blockade of cell cycle was associated with increased levels of p21, and reduced amounts of cyclin B1, cyclin A, Cdc2 and Cdc25C. DGE also enhanced the levels of inactivated phosphorylated Cdc2 and Cdc25C. DGE triggered the mitochondrial apoptotic pathway indicated by a change in Bax/Bcl-2 ratios, resulting in caspase-9 activation. We also found the generation of reactive oxygen species is a critical mediator in DGE-induced cell growth inhibition. DGE clearly increased the activation of apoptosis signal-regulating kinase 1 and c-Jun N-terminal kinase (JNK), but not extracellular signal-regulated kinase 1/2 (ERK1/2) and p38. In addition, antioxidants vitamin C and catalase significantly decreased DGE-mediated JNK activation and apoptosis. Moreover, blocking JNK by specific inhibitors suppressed DGE-triggered mitochondrial apoptotic pathway. Taken together, these findings suggest that a critical role for reactive oxygen species and JNK in DGE-mediated apoptosis of human breast cancer.
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PMID:6-Dehydrogingerdione, an active constituent of dietary ginger, induces cell cycle arrest and apoptosis through reactive oxygen species/c-Jun N-terminal kinase pathways in human breast cancer cells. 2017 81

Platycodin D (PD), a major constituent isolated from the root of Platycodon grandiflorum, has been suggested to possess anticancer activities, as indicated by its capabilities to induce mitotic arrest and apoptosis in several cancer cells. However, little is known of the underlying action mechanism. This study is the first to investigate the anticancer effect of PD in the human breast cancer cell, MCF-7. Our data showed that PD exhibited marked cell growth inhibition by inducing apoptosis. This induction was associated with activation of caspase-8 and -9 activities and poly(ADP-ribose) polymerase. PD triggered the mitochondrial apoptotic pathway, as indicated by up-regulation of levels of cellular Bax and down-regulation of levels of Bcl-2 and caspase-9 activation. We found that PD induced proteolytic activation of Bid, a member of the proapoptotic Bcl-2 family, implicating PD-induced apoptosis as possibly being functionally linked to a death receptor-mediated pathway. The PD treatment also was accompanied by an increase in cellular generation of reactive oxygen species, indicating that PD-induced apoptosis is likely to be mediated through mitochondrial dysfunction. In addition, we revealed that the mitogen-activated protein kinases, including extracellular signal-regulated kinase 1/2, c-Jun NH(2)-terminal kinase 1/2, and p38, which play important roles in apoptosis, were activated by treatment with PD. These results provide a basic mechanism for the anticancer properties of PD and suggest that PD is a promising candidate for chemotherapy and chemoprevention of breast cancer.
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PMID:Platycodin D induces apoptosis in MCF-7 human breast cancer cells. 2041 17

The expression of cell differentiation and proliferation markers of canine neuroepithelial tumors was examined immunohistochemically to identify the histogenesis of these tumors. Astrocytomas (n = 4) consisted of cells positive for glial fibrillary acidic protein (GFAP) and nestin and a few cells positive for doublecortin (DCX). Immunoreactive cells for receptor tyrosine kinases (epidermal growth factor receptor and c-erbB2) and their downstream molecules (phospho-extracellular signal-regulated kinase 1/2 and phospho-Akt) were often detected in astrocytomas, especially in medium- and high-grade tumors. Gliomatosis cerebri (n = 3) consisted of cells positive for ionized calcium-binding adaptor molecule 1 and GFAP, including a minor population of cells positive for nestin, DCX, and beta III tubulin, suggesting their glial differentiation. In choroid plexus tumors (n = 4), most tumor cells were positive for cytokeratins AE1/AE3 and 18, and few were positive for GFAP. The majority of cells of oligodendrogliomas (n = 5) were DCX positive, but the tumors also contained minor populations of cells positive for GFAP, nestin, or beta III tubulin. Primitive neuroectodermal tumors (PNETs; n = 2) consisted of heterogeneous cell populations, and the tumor cells were positive for nestin, beta III tubulin, and DCX, suggesting glial and neuronal differentiation. The major population of neuroblastoma cells (n = 3) were positive for beta III tubulin and DCX, suggesting single neuronal differentiation. As for antiapoptotic cell death molecules, most tumor cells in the choroid plexus tumors, PNETs, and neuroblastomas were intensely positive for Bcl-2 and Bcl-xL, whereas those in gliomatosis cerebri were almost negative. In astrocytomas, Bcl-xL-positive cells predominated over Bcl-2-positive cells, but the opposite was observed in oligodendrogliomas. The immunohistochemical results were analyzed by hierarchical clustering, and the constructed dendrogram clearly indicated a novel position of oligodendrogliomas: the primitive glial and neuronal differentiation.
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PMID:Immunohistochemical characterization of canine neuroepithelial tumors. 2041 71


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