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Query: UNIPROT:P10415 (
Bcl-2
)
33,771
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) is a mammary gland carcinogen in cooked meat. Using the HC11 mouse mammary epithelial cell line, a well-characterized model for hormone-mediated differentiation, we examined whether PhIP altered the expression of genes regulated by lactogenic hormones dexamethasone, insulin, and prolactin (DIP). When HC11-Lux cells (stably transfected with a beta-casein promoter luciferase construct) were cultured in DIP-containing medium, PhIP (100 microM) enhanced luciferase activity 11-fold over that observed in DIP medium alone. The effect of PhIP on augmenting luciferase activity was observed only when lactogenic hormones were included in the medium. Expression of the endogenous beta-casein gene was also higher in HC11 cells treated with PhIP in hormone-enriched medium. With the increased expression of beta-casein gene, the level of phospho-signal transducer and activator of transcription 5A (phospho-STAT5A), the transcription factor regulating beta-casein gene expression, was elevated in PhIP-exposed HC11 cells. AG490, a
Janus kinase 2
(
JAK2
)-specific inhibitor, blocked the effect of PhIP on beta-casein gene expression. PhIP-treated cells also showed higher expression of
Bcl-2
and lower expression of Bax, consistent with a possible antiapoptotic action of PhIP. The findings indicate that PhIP modulates lactogenic hormone-mediated gene expression in mammary epithelial cells, apparently via enhanced phosphorylation of STAT5A. The findings have implications for a novel mechanism of action of the mammary gland carcinogen PhIP.
...
PMID:2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) modulates lactogenic hormone-mediated differentiation and gene expression in HC11 mouse mammary epithelial cells. 1175 60
Tissue inhibitors of metalloproteinases (TIMPs) are important regulators of matrix metalloproteinase (MMP) and adamalysin metalloproteinase activity. We previously reported that overexpression of TIMP-3 inhibits MMPs and induces apoptotic cell death in a variety of cell types and demonstrated that apoptosis is mediated through the N terminus of TIMP-3, which harbors the MMP inhibitory domain. However, little is known about the mechanisms underlying TIMP-3-induced apoptosis. Here we demonstrate that overexpression of TIMP-3 induced activation of initiator caspase-8 and -9 and promoted caspase-mediated cleavage of the death substrates poly(ADP-ribose) polymerase and
focal adhesion kinase
. Furthermore, TIMP-3 induced mitochondrial activation as demonstrated by loss of mitochondrial membrane potential and release of cytochrome c. Intervention studies demonstrated that overexpression of
Bcl-2
, the anti-apoptotic mitochondrial membrane protein, or CrmA, a viral serpin inhibitor of caspase-8, completely inhibited TIMP-3-induced apoptosis. Furthermore, a dominant-negative Fas-associated death domain mutant inhibited TIMP-3-induced death substrate cleavage and apoptotic death. Taken together, these results indicate that TIMP-3 overexpression induces a type II apoptotic pathway initiated via a Fas-associated death domain-dependent mechanism.
...
PMID:Tissue inhibitor of metalloproteinase-3 induces a Fas-associated death domain-dependent type II apoptotic pathway. 1182 69
Akt/
PKB
is a serine/threonine protein kinase that regulates cell cycle progression, apoptosis and growth factor mediated cell survival in association with tyrosine kinase receptors. The protein is a downstream effector of erbB-2 with implications in breast cancer progression and drug resistance in vitro. We aimed to examine the role of Akt-1 in breast cancer patients, by determining whether the expression (Akt-1) and/or activation (pAkt) were related to prognostic markers and survival. The expression of erbB-2, heregulin beta 1 and
Bcl-2
was also assessed by flow cytometry or immunohistochemistry. This study comprised 93 patients, aged <50 who were treated with tamoxifen and/or goserelin. We found that pAkt was associated with lower S-phase fraction (P=0.001) and the presence of heregulin beta 1-expressing stromal cells (P=0.017). Neither Akt-1 nor pAkt was related with other factors. Tumour cells-derived heregulin beta 1 was found mainly in oestrogen receptor negative (P=0.026) and node negative (P=0.005) cases. Survival analysis revealed that pAkt positive patients were more prone to relapse with distant metastasis, independently of S-phase fraction and nodal status (multivariate analysis; P=0.004). The results suggest that activation of Akt may have prognostic relevance in breast cancer.
...
PMID:Activation of AKT/PKB in breast cancer predicts a worse outcome among endocrine treated patients. 1187 May 34
B cell susceptibility to Fas-mediated apoptosis is regulated in a receptor-specific fashion. CD40 engagement produces marked sensitivity to Fas killing, whereas surface Ig (sIg) engagement blocks Fas signaling for cell death in otherwise sensitive, CD40-stimulated B cell targets, and thus, induces a state of Fas resistance. The signaling mediator,
Bruton's tyrosine kinase
(
Btk
), is required for certain sIg-triggered responses, and
Btk
is reported to directly bind Fas and block Fas-mediated apoptosis. For these reasons, the role of
Btk
as a mediator of sIg-induced Fas resistance was examined. Dysfunction of
Btk
through mutation, and absence of
Btk
through deletion did not interfere with induction of Fas resistance by anti-Ig. This may be due, at least in part, to induction of
Btk
-dependent
Bcl-2
family members by anti-Ig after CD40 ligand treatment. However, the susceptibility to Fas-mediated apoptosis of B cell targets stimulated by CD40 ligand alone was increased in the absence of
Btk
. These results indicate that Fas resistance produced by sIg triggering does not require
Btk
, but suggests that in certain situations
Btk
modulates B cell susceptibility to Fas killing.
...
PMID:BCR engagement induces Fas resistance in primary B cells in the absence of functional Bruton's tyrosine kinase. 1188 37
To improve implant biocompatibility, we developed a simple cost-effective thermal surface treatment allowing an increase in the oxide layer thickness of a titanium (Ti) alloy used in orthopaedic implants. The goal of this study was to test in vitro the reaction of osteoblasts to the developed surface treatment and to compare it to the osteoblast reaction to two other surface treatments currently used in the practice of implant surgery. Quantification of osteoblast gene expression on a large scale was used in this study. The kinetics of gene expression over 120 h was followed for 58 genes to quantify the effect of the developed surface treatment. Twenty eight genes were further selected to compare the effects of surface treatments on osteoblasts. Based on the genes studied, we could propose a general pathway for the cell reaction according to the surface treatments used: (1) metal ion release changes the time course of gene expression in the
FAK
pathway; (2) once the accumulation of metal ions released from the Ti surface exceeds a threshold value, cell growth is diminished and apoptosis may be activated; (3) PTK up-regulation is also induced by metal ion release; (4) the expression of
Bcl-2
family and Bax may suggest that metal ions induce apoptosis. The developed treatment seems to increase the Ti-6Al-4V biocompatibility as highlighted by the lower impact of this treatment by the different pathways studied, on the lower inflammatory reaction that could be induced, as well as by the lower induced osteoblast apoptosis compared to the two other surface treatments.
...
PMID:Large-scale gene expression analysis of osteoblasts cultured on three different Ti-6Al-4V surface treatments. 1219 22
Hepatocellular carcinoma (HCC) is one of the most common reasons for malignancy-related death in Africa and Asia and is still recognised as the leading cancer in men in Taiwan. Despite enthusiastic efforts in early diagnosis, aggressive surgical treatment and application of additional nonoperative modalities, its prognosis is still dismal. This emphasises the necessity to develop new measures and strategies for its prevention. Inducible cyclooxygenease 2 (COX-2) is an immediate-early (IE) response gene and extensive studies conducted over the past few years have recognised its overexpression in several carcinomas and thus its implication in carcinogenesis. Recent studies have suggested that overexpression of COX-2 might be one of the leading factors in hepatic carcinogenesis. COX-2 can induce angiogenesis via vascular endothelial growth factor (VEGF) and prostaglandin production and can also inhibit apoptosis by inducing the antiapoptotic factor
Bcl-2
as well as activating antiapoptotic signalling through Akt/
PKB
. Therefore, the use of selective inhibitors for the downregulation of COX-2 activity might be a target for preventing hepatic carcinoma development.
...
PMID:COX-2 - a target for preventing hepatic carcinoma? 1222 62
In the present paper we show that transendothelial migration of a subset of CD14(+) circulating leukocytes, coexpressing the CD34 precursor marker, leads to protection from the apoptosis that follows growth factor(s) withdrawal. The resistance of this cell subset to starvation-induced programmed cell death, lasting from 48 to 96 hours, is accompanied by a rise of mitochondrial adenosine triphosphate (ATP), a high nicotinamide adenine dinucleotide (NAD)/reduced nicotinamide adenine dinucleotide (NADH) ratio, and by the up-regulation of expression of the antiapoptotic proteins
Bcl-2
and Bcl-X, together with an increase in the cytoplasmic, inactive, form of Bax. This suggests that protection from apoptosis is due to the preservation of mitochondrial function(s). Interestingly, ligation of the platelet endothelial cell adhesion molecule-1 (PECAM-1), which drives CD14(+)CD34(+) transendothelial migration, leads to an increase in
Bcl-2
A1 and Bcl-X intracellular content, and to protection from starvation-induced apoptosis. This event is dependent on the engagement of phosphatidylinositol-3 kinase and activation of Akt/
PKB
that is known to contribute to
Bcl-2
and Bcl-X induction. These data point to a critical role of endothelium in preventing the apoptotic program triggered by starvation, possibly inducing a prolonged survival of antigen presenting cell precursors, in order to allow recirculation of these cells and localization to the site of priming of T lymphocytes.
...
PMID:Transendothelial migration leads to protection from starvation-induced apoptosis in CD34+CD14+ circulating precursors: evidence for PECAM-1 involvement through Akt/PKB activation. 1239 47
Dendritic cells (DCs) are the most important antigen-presenting cells. Many recent studies have compared the function of immature DCs (iDCs) and mature DCs (mDCs), but there have been few reports of the molecular changes that occur in DCs during maturation. Here, we report on differential gene expression in iDCs generated from peripheral blood monocytes compared with mDCs. Gene expression was evaluated using the differential display method after activation of iDCs with a low concentration of lipopolysaccharide (LPS) to induce maturation. Proteasome subunit alpha type 3 (PSMA3), transcription factor EC (TFEC) isoform and
BTK
region clone 2f10-rpi were transiently upregulated. Tryptophanyl-tRNA synthetase and CD63 antigen were upregulated for at least 24 h. Neuronal apoptosis inhibitory protein (NAIP) and transforming growth factor-beta-induced 68 kDa protein were downregulated. This is the first report of NAIP expression in human DCs. By comparing the expression of NAIP with that of other members of the inhibitor of apoptosis protein (IAP) family and the
Bcl-2
family, only NAIP was found to be strongly expressed in iDCs before stimulation by LPS. PSMA3 was also induced in the DCs stimulated with immune complex. These findings might contribute to our understanding of DC maturation and the effectiveness of DC-based vaccines.
...
PMID:Analysis of gene expression during maturation of immature dendritic cells derived from peripheral blood monocytes. 1247 71
Hematopoietic malignancies have been shown to depend on cytokine growth factor autocrine/paracrine loops for growth and differentiation. This results in the constitutive activation of cytokine-mediated transcription factors like signal transducer and activators of transcription (STAT) 3 in non-Hodgkin's lymphoma (NHL) and multiple myeloma (MM). Recent evidence demonstrates that cytokines also contribute to a drug-resistant phenotype in many tumor cell types. We hypothesized that inhibitors of the STAT3 pathway would sensitize drug-resistant and endogenous cytokine-dependent NHL and MM tumor cells to the cytotoxic effects of chemotherapeutic drugs. We examined an AIDS-related NHL cell line, 2F7, known to be dependent on interleukin (IL)-10 for survival and an MM cell line, U266, known to be dependent on IL-6 for survival. IL-10 and IL-6 signal the cells through the activation of Janus kinase (JAK)1 and
JAK2
, respectively. Thus, we investigated the effect of two chemical STAT3 pathway inhibitors, namely, piceatannol (
JAK1
/STAT3 inhibitor) and tyrphostin AG490 (
JAK2
/STAT3 inhibitor), on the tumor cells for sensitization to therapeutic drugs. We demonstrate by phosphoprotein immunoblotting analysis and electrophoretic mobility shift analysis that piceatannol and AG490 inhibit the constitutive activity of STAT3 in 2F7 and U266, respectively. Furthermore, piceatannol and AG490 sensitize 2F7 and U266 cells, respectively, to apoptosis by a range of therapeutic drugs including cisplatin, fludarabine, Adriamycin, and vinblastine. The specificity of the inhibitors was corroborated in experiments showing that piceatannol had no effect on U266 and, likewise, AG490 has no effect on 2F7. The sensitization observed by these inhibitors correlated with the inhibition of
Bcl-2
expression in 2F7 and Bcl-xL expression in U266. Altogether, these results demonstrate that STAT3 pathway inhibitors are a novel class of chemotherapeutic sensitizing agents capable of reversing the drug-resistant phenotype of cytokine-dependent tumor cells.
...
PMID:Inhibition of constitutive STAT3 activity sensitizes resistant non-Hodgkin's lymphoma and multiple myeloma to chemotherapeutic drug-mediated apoptosis. 1253 84
To study the molecular mechanisms by which drug resistance develops, we compared DU145 humanprostate cancer cells with a subline selected for resistance to camptothecin. Differences in gene expression level were assessed by hybridizing the two cell types against each other using quadruplicate "Oncochip" cDNA microarrays that included 1648 cancer-related genes. Expression levels differing by a factor of >1.5 were detected for 181 of the genes. These differences were judged statistically reliable on the basis of a stratum-adjusted Kruskal-Wallis test, after taking into account a dye-dependent variable. The 181 expression-altered genes included a larger than expected number of the "apoptosis-related" genes (P = 0.04). To assess whether this observation reflected a generalized resistance of RCO.1 to apoptosis, we exposed the cells to a range of stresses (cisplatin, staurosporine, UV, ionizing radiation, and serum starvation) and found greatly reduced apoptotic responses for RC0.1 (relative to DU145) using flow cytometric Annexin V and terminal deoxynucleotidyl transferase-mediated nick end labeling assays. We next examined the apoptosis-related genes in the context of a molecular interaction map and found expression differences in the direction "expected" on the basis of the apoptosis-resistance of RC0.1 for BAD, caspase-6, and genes that signal via the Akt pathway. Exposure of the cells to wortmannin, an inhibitor of the Akt effector phosphatidylinositol 3-kinase, provided functional support for involvement of the Akt pathway. However, closer examination of the molecular interaction map revealed a paradox: many of the expression differences observed for apoptosis-related genes were in the direction "contrary" to that expected given the resistance of RC0.1. The map indicated that most of these unexpected expression differences were associated with genes involved in the nuclear factor kappa B and transforming growth factor beta pathways. Overall, the patterns that emerged suggested a two-step model for the selection process that led to resistance in RC0.1 cells. The first hypothesized step would involve a decrease in apoptotic susceptibility through changes in the apoptosis-control machinery associated with the
Bcl-2
and caspase gene families, and also in antiapoptotic pathways operating through Akt/
PKB
. The second step would involve changes in multifunctional upstream genes (including some genes in the nuclear factor kappa B and transforming growth factor beta pathways) that can facilitate apoptosis but that would also tend to contribute to cell proliferation in the presence of drug. Thus, we propose that a downstream blockade of apoptosis was "permissive" for the selection of upstream pathway changes that would otherwise have induced apoptosis. This model is analogous to one suggested previously for the relationship between oncogene function and apoptosis in carcinogenesis.
...
PMID:Apoptotic susceptibility of cancer cells selected for camptothecin resistance: gene expression profiling, functional analysis, and molecular interaction mapping. 1261 15
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