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

To investigate the involvement of reactive oxygen species (ROS) in neuronal apoptosis, we performed confocal and flow cytometric analysis with a ROS-specific fluorogen, 6-carboxy-2', 7'-dichorodihydrofluorescein diacetate, di(acetoxymethyl ester) (C-DCDHF-DA). Serum deprivation significantly increased the level of ROS in PC12 cells and rat cortical neurons. N,N'-diphenyl-p-phenylenediamine (DPPD), an antioxidant, reduced ROS production induced by serum deprivation and recovered cell survival. However, some survival factors such as nerve growth factor and Bcl-2, which prevented the apoptosis of PC12 cells, did not affect the up-regulation of ROS induced by serum deprivation. Epidermal growth factor which prevented the apoptosis of cortical neurons, did not affect the increase of ROS. These data suggest that survival factors rescue the serum deprivation induced apoptosis independently of ROS production.
 ...
PMID:Survival factor-insensitive generation of reactive oxygen species induced by serum deprivation in neuronal cells. 889 Dec 42

Epidermal growth factor (EGF) protects against death receptor induced apoptosis in epithelial cells. Herein, we demonstrate that EGF protection against tumor necrosis factor related apoptosis-inducing ligand (TRAIL) induced apoptosis is mediated by increased expression of the Bcl-2 family member myeloid cell leukemia 1 (Mcl-1). EGF increased the mRNA and protein levels of Mcl-1. Furthermore, expression of ErbB1 alone or in combination with ErbB2 in NIH3T3 cells up-regulates Mcl-1 following EGF treatment. In addition, up-regulation of Mcl-1 by EGF is mediated through AKT and NFkappaB activation since kinase inactive AKT and DeltaIkappaB effectively blocks this up-regulation. NFkappaB was also critical for the ability of EGF to prevent TRAIL induced apoptosis as a dominant negative IkappaB (DeltaIkappaB) blocked NFkappaB activation, and relieved EGF protection against TRAIL mediated mitochondrial cytochrome-c release and apoptosis. Finally, anti-sense oligonucleotides directed against Mcl-1 effectively reduced the protein levels of Mcl-1 and blocked EGF protection against TRAIL induced mitochondrial cytochrome-c release and apoptosis. Taken together, EGF signaling leads to increased Mcl-1 expression that is required for blockage of TRAIL induced apoptosis.
 ...
PMID:Increased expression of Mcl-1 is responsible for the blockage of TRAIL-induced apoptosis mediated by EGF/ErbB1 signaling pathway. 1289 16

Thrombospondins (TSPs) have been implicated as antitumor and antimetastasis factors in breast cancer. Although this effect has been attributed to the antiangiogenic activity of TSPs, recent observations suggest other mechanisms may be at work. The TSP receptor CD47 (integrin-associated protein) has recently been reported to mediate a novel form of apoptosis. Here, we have studied the response of breast cancer cells to CD47 ligands TSP-1, the CD47 agonist peptide 4N1K derived from TSP-1, and the anti-CD47 monoclonal antibody 1F7. All of these ligands killed four different breast cancer cell lines. This CD47-mediated cell death did not require active caspases or Bcl-2 degradation and did not cause DNA laddering or cytochrome c release. Pertussis toxin (PTX) prevented CD47-mediated death, indicating the involvement of Gi alpha. 4N1K dramatically reduced intracellular cAMP levels, an effect reversed with PTX. Forskolin, 8-bromo cAMP, and isobutylmethylxanthine (IBMX) all prevented CD47-mediated apoptosis, indicating the involvement of cAMP. H89 and protein kinase A (PKA) inhibitor peptide prevented rescue of breast cancer cells by PTX, 8-Br-cAMP, and forskolin, suggesting that the effects of cAMP are mediated via PKA-dependent phosphorylation events. Epidermal growth factor also inhibited CD47-induced apoptosis via a PKC-dependent but ERK-independent pathway. Thus, CD47-mediated killing of breast cancer cells occurs by a novel pathway involving regulation of cAMP levels by heterotrimeric Gi with subsequent effects mediated by PKA.
 ...
PMID:CD47 mediates killing of breast tumor cells via Gi-dependent inhibition of protein kinase A. 1487 34

Cell shrinkage is an integral part of apoptosis. However, intimate mechanisms linking apoptotic events to the alterations in cell volume homeostasis remain poorly elucidated. We investigated how overexpression of Bcl-2 oncoprotein, a key antiapoptotic regulator, in lymph node carcinoma of the prostate (LNCaP) prostate cancer epithelial cells interferes with the volume-regulated anion channel (VRAC), a major determinant of regulatory volume decrease. Bcl-2 overexpression resulted in the doubling of VRAC-carried swelling-activated Cl(-) current (I(Cl,swell)) and weakened I(Cl,swell) inhibition by store-operated Ca(2+) channel (SOC)-transported Ca(2+). This also was accompanied by substantial up-regulation of ClC-3 protein, a putative molecular candidate for the role of VRAC. ClC-3-specific antibody suppressed I(Cl,swell) in the wild-type and Bcl-2-overexpressing LNCaP cells. Epidermal growth factor treatment of wild-type LNCaP cells, promoting their proliferation, resulted in the enhancement of endogenous Bcl-2 expression and associated increases in ClC-3 levels and I(Cl,swell) magnitude. We conclude that Bcl-2-induced up-regulation of I(Cl,swell), caused by enhanced expression of ClC-3 and weaker negative control from SOC-transported Ca(2+), would strengthen the ability of the cells to handle proliferative volume increases and thereby promote their survival and diminish their proapoptotic potential.
 ...
PMID:Bcl-2-dependent modulation of swelling-activated Cl- current and ClC-3 expression in human prostate cancer epithelial cells. 1525 54

Programmed cell death (PCD) is physiologically involved in the regulation of cell division and differentiation. It encompasses caspase-dependent mitochondrial and nonmitochondrial pathways. Additional caspase-independent pathways have been characterized in mitochondrial PCDs but remain hypothetical in nonmitochondrial PCDs. Epidermal growth factor (EGF) has been shown to inhibit division of pituitary somato-lactotrope cells occurring in parallel with EGF-mediated differentiation of these precursors into lactotrope cells. We show here that in somato-lactotrope pituitary cell line GH4C1, EGF triggers a PCD characterized by an apoptosis-like DNA fragmentation, insensitivity to broad-range caspase inhibitors, and absence of either cytochrome c or apoptosis-inducing factor release from mitochondria. Dying cells display loose chromatin clustering and numerous cytoplasmic vacuoles, a fraction of which are autophagic, thus conferring a heterogeneous phenotype to this PCD. Moreover, overexpression of cell death inhibitor Bcl-2 prevented not only the EGF-induced PCD but also its prodifferentiation effects, thus pointing to a mechanistic relationship existing between these two phenomena. Overall, the characterized differentiation-linked cell death represents an original form of caspase-independent PCD. The mechanisms underlying this PCD involve combinatorial engagement of discrete death effectors leading to a heterogeneous death phenotype that might be evolutionary related to PCD seen during the differentiation of some unicellular organisms.
 ...
PMID:Epidermal growth factor triggers an original, caspase-independent pituitary cell death with heterogeneous phenotype. 1533 66

The mitochondria-mediated apoptotic pathway is regulated by members of the Bcl-2 family. Epidermal growth factor (EGF) induces Bad phosphorylation at Ser112 via mitogen-activated protein kinase (MAPK), impairing its binding to Bcl-2 and Bcl-xL and interfering with their anti-apoptotic functions. In the current study, we utilized Western blot, immunofluorescence, flow cytometry, and confocal microscopy to examine the effects of CMTM8 overexpression on apoptosis. Our data indicated levels of Bad-S112 phosphorylation were lower in CMTM8-transfected cells compared to pCDB-transfected cells. Caspase-dependent and independent mediated apoptosis, induced by CMTM8 overexpression, was facilitated by the mitochondria and inhibited by knockdown of Bad or overexpression of Bcl-xL. Previous research in our laboratory also demonstrated CMTM8 attenuated EGFR-mediated signaling pathways by decreasing ERK1/2 phosphorylation levels. These data implicate CMTM8 as a negative regulator of EGF-induced signaling, with potential use as a novel therapeutic gene for EGFR-targeted anticancer gene therapy.
 ...
PMID:CMTM8 induces caspase-dependent and -independent apoptosis through a mitochondria-mediated pathway. 1714 3

Epidermal growth factor (EGF) is known to be involved in the proliferation and metastasis of squamous cell carcinoma (SCC), suggesting that the EGF receptor (EGFR) must also contribute to SCC development. In combination with conventional anti-cancer drugs, agents that block EGFR may represent an efficient means of inhibiting proliferation and inducing apoptosis in SCC cells. We investigated the effects of combining an anti-EGFR monoclonal antibody (C225) or an EGFR-selective tyrosine kinase inhibitor (AG1478) with the conventional anti-cancer drug cisplatin on the oral SCC (OSCC) cell lines NA and Ca9-22. We detected constitutive expression of EGFR on the cell membranes of both cell lines. OSCC cell proliferation was inhibited by C225, AG1478 and cisplatin in a dose-dependent manner. The combination of C225 or AG1478 with cisplatin at concentrations <IC50 synergistically inhibited cell proliferation and induced apoptosis in these cells. Furthermore, treatment with C225 or AG1478 OSCC reduced phosphorylation of EGFR and Akt, as well as Bad. EGFR inhibitors down-regulated expression levels of the anti-apoptotic proteins cellular IAP-1 (cIAP-1), X-linked IAP (XIAP), Bcl-2 and Bcl-xL, whereas those of the pro-apoptotic proteins Bax and Bak were up-regulated, and neither cIAP-2 nor survivin were affected. Therefore, EGFR inhibitors can provide partial regulation of cisplatin-mediated apoptosis in OSCC cells by modulating expression of cIAP-1, XIAP, Bcl-2, Bcl-xL, Bax and Bak. These results suggest that EGFR inhibitors may represent a novel strategy for overcoming resistance to cisplatin-mediated apoptosis via the phosphatidylinositol 3-kinase/Akt pathway.
 ...
PMID:Effect of combining epidermal growth factor receptor inhibitors and cisplatin on proliferation and apoptosis of oral squamous cell carcinoma cells. 1748 68

Apoptosis is the predominant process controlling cell deletion during post-lactational mammary gland remodeling. The members of the Bcl-2 protein family, whose expression levels are under the control of lactogenic hormones, internally control this mechanism. Epidermal growth factor (EGF) belongs to a family of proteins that act as survival factors for mammary epithelial cells upon binding to specific membrane tyrosine kinase receptors. Expression of EGF peaks during lactation and dramatically decreases in the involuting mammary gland. Though it was suggested that the protective effect of EGF is mediated through the phosphatidylinositol-3-kinase (PI3K) or MEK/ERK kinases activities, little is known about the downstream mechanisms involved on the anti-apoptotic effect of EGF on mammary epithelial cells; particularly the identity of target genes controlling apoptosis. Here, we focused on the effect of EGF on the survival of mammary epithelial cells. We particularly aimed at the characterization of the signaling pathways that were triggered by this growth factor, impinge upon expression of Bcl-2 family members and therefore have an impact on the regulation of cell survival. We demonstrate that EGF provokes the induction of the anti-apoptotic isoform Bcl-XL and the phosphorylation and down-regulation of the pro-apoptotic protein Bad. The activation of JNK and PI3K/AKT signaling pathways promotes the induction of Bcl-XL while AKT activation also leads to Bad phosphorylation and down-regulation. This protective effect of EGF correlates mainly with the up-regulation of Bcl-XL than with the down-regulation of Bad. In fact, HC11 cells unable to express bcl-X, die even in the presence of EGF. In this context, Bcl-XL emerges as a key anti-apoptotic molecule critical for mediating EGF cell survival.
 ...
PMID:Bcl-XL mediates epidermal growth factor dependent cell survival in HC11 mammary epithelial cells. 1912 40

Myeloid cell leukaemia-1 (Mcl-1) is an anti-apoptotic member of the Bcl-2 family that is elevated in a variety of tumour types including breast cancer. In breast tumours, increased Mcl-1 expression correlates with high tumour grade and poor patient survival. We have previously demonstrated that Her-2 levels correspond to increased Mcl-1 expression in breast tumours. Epidermal growth factor (EGF) receptor signalling is frequently deregulated in breast cancer and leads to increased proliferation and survival. Herein, we determined the critical downstream signals responsible for the EGF mediated increase of Mcl-1 and their role in cell survival. We found that both Mcl-1 mRNA and protein levels are rapidly induced upon stimulation with EGF. Promoter analysis revealed that an Elk-1 transcription factor-binding site is critical for EGF activation of the Mcl-1 promoter. Furthermore, we found that knockdown of Elk-1 or inhibition of the Erk signalling pathway was sufficient to block EGF upregulation of Mcl-1 and EGF mediated cell survival. Using chromatin immunoprecipitation and biotin labelled probes of the Mcl-1 promoter, we found that Elk-1 and serum response factor are bound to the promoter after EGF stimulation. To determine whether Mcl-1 confers a survival advantage, we found that knockdown of Mcl-1 expression increased apoptosis whereas overexpression of Mcl-1 inhibited drug induced cell death. In human breast tumours, we found a correlation between phosphorylated Elk-1 and Mcl-1 protein levels. These results indicate that the EGF induced activation of Elk-1 is an important mediator of Mcl-1 expression and cell survival and therefore a potential therapeutic target in breast cancer.
 ...
PMID:Epidermal growth factor regulates Mcl-1 expression through the MAPK-Elk-1 signalling pathway contributing to cell survival in breast cancer. 2125 8

Malignant mesothelioma is a rare, highly aggressive cancer arising from mesothelial cells that line the pleural cavities. Approximately 80% of mesothelioma cases can be directly attributed to asbestos exposure. Additional suspected causes or co-carcinogens include other mineral fibres, simian virus 40 (SV40) and radiation. A mesothelioma epidemic in Turkey has demonstrated a probable genetic predisposition to mineral fibre carcinogenesis and studies of human tissues and animal models of mesothelioma have demonstrated genetic and epigenetic events that contribute to the multistep process of mineral fibre carcinogenesis. Several growth factors and their receptors have a significant role in the oncogenesis, progression and resistance to therapy of mesothelioma. Epidermal growth factor (EGF), hepatocyte growth factor (HGF), vascular endothelial growth factor (VEGF) and insulin-like growth factor (IGF) have been shown as targets for therapy based on promising preclinical data. However, clinical trials of tyrosine kinase inhibitors in mesothelioma have been disappointing. Bcl-XL is an important antiapoptotic member of the Bcl-2 family and is overexpressed in several solid tumours, including mesothelioma. Reduction of Bcl-XL expression in mesothelioma induces apoptosis and engenders sensitisation to cytotoxic chemotherapeutic agents. Pharmacological inhibitors of antiapoptotic Bcl-2 family members continue to undergo refinement and have shown promise in mesothelioma.
 ...
PMID:Molecular pathogenesis of malignant mesothelioma. 2262 48


1 2 Next >>