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Query: UNIPROT:P42574 (
caspase-3
)
45,978
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
The probasin (Pb)-PRL transgenic mice that overexpress the rat PRL gene specifically in the prostate develop a dramatic enlargement of the prostate gland. The objective of this study was to characterize the molecular mechanisms involved in the prostate hyperplasia seen in the Pb-PRL transgenic mice. cDNA microarray analysis was used to identify differentially expressed transcripts in the hyperplastic prostates of 6-month-old transgenic mice compared with age-matched controls. We report the identification of 266 genes (175 up-regulated and 91 down-regulated) that were differentially expressed in the enlarged transgenic prostates compared with controls. Subsequential real-time RT-PCR was used to verify a set of differentially regulated transcripts. The hyperplastic prostates of Pb-PRL transgenic mice demonstrate a molecular pattern supporting the importance of reduced degree of apoptosis for the development of the phenotype. Immunohistochemical analysis of apoptotic activity using two different markers of apoptosis (single-stranded DNA and activated
caspase-3
) were performed, and the results showed diminished apoptosis activity in the prostate of Pb-PRL transgenic mice compared with control prostates. The increased stromal/epithelial ratio of the Pb-PRL transgenic prostate together with up-regulation of a significant fraction of genes involved in tissue remodeling activity, including the synthesis and degradation of the extracellular matrix and changes in protease activity, suggest that activation of the stroma is involved in the development of prostate hyperplasia. Overall, the differentially expressed transcripts identified in this study show many molecular similarities between the prostate hyperplasia of PRL-transgenic mice and human prostate pathology, including both benign prostatic hyperplasia and
prostate cancer
.
...
PMID:Gene expression analysis of prostate hyperplasia in mice overexpressing the prolactin gene specifically in the prostate. 1296 74
Integrins are cell surface heterodimeric transmembrane receptors that, in addition to mediating cell adhesion to extracellular matrix proteins modulate cell survival. This mechanism may be exploited in cancer where evasion from apoptosis invariably contributes to cellular transformation. The molecular mechanisms responsible for matrix-induced survival signals begin to be elucidated. Here we report that the inhibitor of apoptosis survivin is expressed in vitro in human prostate cell lines with the highest levels present in aggressive
prostate cancer
cells such as PC3 and LNCaP-LN3 as well as in vivo in prostatic adenocarcinoma. We also show that interference with survivin in PC3
prostate cancer
cells using a Cys84--> Ala dominant negative mutant or survivin antisense cDNA causes nuclear fragmentation, hypodiploidy, cleavage of a 32-kDa proform
caspase-3
to active
caspase-3
, and proteolysis of the caspase substrate poly(ADP-ribose) polymerase. We demonstrate that in the aggressive PC3 cell line, adhesion to fibronectin via beta1 integrins results in up-regulation of survivin and protection from apoptosis induced by tumor necrosis factor-alpha (TNF-alpha). In contrast, survivin is not up-regulated by cell adhesion in the non-tumorigenic LNCaP cell line. Dominant negative survivin counteracts the ability of fibronectin to protect cells from undergoing apoptosis, whereas wild-type survivin protects non-adherent cells from TNF-alpha-induced apoptosis. Evidence is provided that expression of beta1A integrin is necessary to protect non-adherent cells transduced with survivin from TNF-alpha-induced apoptosis. In contrast, the beta1C integrin, which contains a variant cytoplasmic domain, is not able to prevent apoptosis induced by TNF-alpha in non-adherent cells transduced with survivin. Finally, we show that regulation of survivin levels by integrins are mediated by protein kinase B/AKT. These findings indicate that survivin is required to maintain a critical anti-apoptotic threshold in
prostate cancer
cells and identify integrin signaling as a crucial survival pathway against death receptor-mediated apoptosis.
...
PMID:Fibronectin protects prostate cancer cells from tumor necrosis factor-alpha-induced apoptosis via the AKT/survivin pathway. 1452 21
Inositol hexaphosphate (IP6), a dietary agent, has been extensively studied for its cancer chemopreventive and anti-cancer efficacy in several different animal models, but not in
prostate cancer
(
PCA
) possibly because the known
PCA
models are both expensive and highly time-consuming. One such
PCA
model is transgenic adenocarcinoma of mouse prostate (TRAMP), which reproduces the spectrum of benign latent, aggressive and metastatic forms of human
PCA
. In this study, we investigated the anti-cancer effects of IP6 in TRAMP-derived established TRAMP-C1 cell line. IP6 (0.5-4.0 mM) treatment of cells for 24-72 h resulted in 17-76% cell growth inhibition and 6-35% cell death, in a dose- and time-dependent manner. In the studies assessing whether cell growth inhibition by IP6 is associated with an alteration in cell cycle progression, IP6 treatment resulted in up to 92% cells in G0-G1 phase as compared to controls. In other studies assessing its apoptotic efficacy, IP6 induced a moderate to strong (up to 14-fold over control) apoptotic cell death. In additional studies, pretreatment of cells with all caspases inhibitor for 2 h followed by 2 mM IP6 for 48 h resulted in approximately 50% reversal in IP6-induced apoptosis suggesting a partial involvement of caspases activation in IP6-caused apoptosis. Furthermore, IP6 showed significant induction (6-fold) in
caspase-3
activity compared to control suggesting the involvement of caspases activation in IP6-induced apoptosis. However, pretreatment of cells with all caspase inhibitor, which partially reversed the IP6-induced apoptosis, completely inhibited IP6-induced
caspase-3
activation, providing convincing evidence of both caspase-dependent and -independent mechanisms in IP6-induced apoptotic death of TRAMP-C1 cells. Together, these results warrant further mechanistic and in vivo efficacy studies with IP6 in TRAMP and other pre-clinical models of
PCA
.
...
PMID:Growth inhibitory and apoptotic effects of inositol hexaphosphate in transgenic adenocarcinoma of mouse prostate (TRAMP-C1) cells. 1453 84
G3139 is an 18-mer phosphorothioate oligodeoxyribonucleotide, which is targeted to the initiation codon region of the bcl-2mRNA. Although treatment of PC3
prostate cancer
cells with G3139, which contains two CpG motifs, causes a dramatic decrease in bcl-2 protein expression after 3 days, it did not result in significant cellular apoptosis, as it does in many other cell lines. The absence of apoptosis was demonstrated by the absence of pro-
caspase 3
cleavage products and of Annexin V cell surface expression. In addition, ATP production and the mitochondrial membrane potential DeltaPsim were preserved. Despite this, G3139 significantly inhibited the rate of cellular proliferation in complete media and blocked cloning in soft agar. G4232, a variant of G3139 that down-regulates bcl-2 expression to the same extent but has both CpG cytidines C5 methylated, was only minimally antiproliferative. A series of mismatched G3139-related oligomers were synthesized that could also substantially down-regulate bcl-2 protein expression, but only if the CpG motifs were preserved, demonstrating the presence of additional non-antisense mechanisms. G3139 caused production of reactive oxygen species in growth-arrested cells and oxidation of nuclear guanosine to 8-hydroxy-2'-deoxyguanosine, as determined by 1F7 monoclonal antibody staining. Bromodeoxyuridine incorporation studies demonstrated that G3139 induced a G1-S entry block and an intra-S-phase block in PC3 cells that persisted as long as 3 days. This finding coincides with the observation that expression of several proteins encoded by S-phase genes, including c-myb and poly(ADP-ribose) polymerase, were significantly reduced. These results illustrate the complexity of the mechanism of action of G3139 in PC3 cells.
...
PMID:G3139 (oblimersen) may inhibit prostate cancer cell growth in a partially bis-CpG-dependent non-antisense manner. 1457 68
12-O-tetradecanoylphorbolacetate (TPA) influences proliferation, differentiation, and apoptosis in a variety of cells including
prostate cancer
cells. Here, we show that androgen treatment potentiates TPA-induced apoptosis in androgen-sensitive
prostate cancer
LNCaP cells but not in androgen-independent
prostate cancer
cell lines DU145 and PC-3. The use of the antiandrogen bicalutamide (Casodex) rescued LNCaP cells from 5-alpha-dihydrotestosterone (DHT)/TPA-induced apoptosis, suggesting that DHT/TPA-induced apoptosis is mediated by androgen/androgen receptor (AR). In addition, a
caspase-3
inhibitor (Ac-DEVD-CHO) reduced the level of apoptosis, suggesting that DHT/TPA-mediated apoptosis occurs through a
caspase-3
-dependent pathway. A functional reporter assay using nuclear factor (NF) kappaB-luciferase and an electromobility gel shift assay showed that DHT suppressed NFkappaB activity. In addition, apoptosis mediated by combined DHT/TPA treatment was abrogated by overexpression of the NFkappaB subunit p65 in LNCaP-p65 cells, suggesting that NFkappaB may play an important role in regulating the effects of androgen/AR and TPA on apoptosis. Furthermore, use of the c-Jun N-terminal kinase (JNK) inhibitor SB202190 showed that the combination of DHT/TPA increased JNK activation in LNCaP cells but not in LNCaP-p65 cells, demonstrating that NFkappaB may be able to suppress JNK activity. These results indicate that androgen/AR facilitates TPA-induced apoptosis by interruption of the NFkappaB signaling pathway, leading to activation of JNK in LNCaP cells. These data describe a signaling pathway that could potentially be useful in proposed therapeutic treatment strategies exploiting combinations of different agents that control apoptosis in prostate tumors.
...
PMID:Interruption of nuclear factor kappaB signaling by the androgen receptor facilitates 12-O-tetradecanoylphorbolacetate-induced apoptosis in androgen-sensitive prostate cancer LNCaP cells. 1461 3
Prostate cancer
is a major health threat for American men. Therefore, the development of effective therapeutic options is an urgent issue for
prostate cancer
treatment. In this study, we evaluated the effect of glycogen synthase kinase-3beta (GSK-3beta) suppression on tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-induced apoptosis in human
prostate cancer
cell lines. In the presence of lithium chloride (LiCl) or SB216763, the GSK-3beta inhibitors, TRAIL-induced cell death was dramatically enhanced, and the enhanced cell death was an augmented apoptotic response evidenced by increased Annexin V labeling and
caspase-3
activation. GSK-3beta gene silencing mediated by a small interference RNA (siRNA) duplex also sensitized the cells to TRAIL, confirming the specificity of GSK-3beta suppression. Importantly, TRAIL stimulation increased GSK-3beta tyrosine phosphorylation at Y216, suggesting that GSK-3beta is activated by TRAIL. Furthermore, TRAIL sensitization was associated with increased proteolytic procession of caspase-8 and its downstream target BID, and z-IETD-FMK, the inhibitor specific to active caspase-8 totally blocked LiCl-induced TRAIL sensitization. Finally, Trichodion, a potent nuclear factor-kappaB (NF-kappaB) inhibitor, could not affect LiCl-induced TRAIL sensitization, although GSK-3beta inhibitors significantly blocked TRAIL-reduced NF-kappaB activity in
prostate cancer
cells. These results indicate that GSK-3beta suppression sensitizes
prostate cancer
cells to TRAIL-induced apoptosis that is dependent on caspase-8 activities but independent of NF-kappaB activation, and suggest that a mechanism involving GSK-3beta activation may be responsible for TRAIL resistance in
prostate cancer
cells.
...
PMID:Glycogen synthase kinase-3beta suppression eliminates tumor necrosis factor-related apoptosis-inducing ligand resistance in prostate cancer. 1461 95
Insulin-like growth factor binding protein-related protein 1 (IGFBP-rP1), a member of the IGFBP super family, is down-regulated at the mRNA level in several solid cancers. We hypothesize that IGFBP-rP1 has a tumor-suppressive effect on
prostate cancer
growth and its inactivation is through CpG hypermethylation. We tested this hypothesis through expression analysis of IGFBP-rP1, transfection studies, growth analysis, and CpG methylation in
prostate cancer
cells and tissues. In situ hybridization revealed IGFBP-rP1 mRNA expression was detected in the stroma and epithelium of benign prostatic hyperplasia tissues but was either weak or lost in
prostate cancer
tissues. The mRNA expression for IGFBP-rP1 was lacking in DU145, LNCaP, ND-1, and PC-3
prostate cancer
cell lines, and after demethylation (5-aza-dC treatment), the expression was restored suggesting that methylation inactivated IGFBP-rP1 expression in
prostate cancer
cells. We further tested whether transfection of IGFBP-rP1 can modulate
prostate cancer
cells growth. We transfected PC-3 cell lines with IGFBP-rP1 cDNA (PC-3-rP1) and Northern blotting confirmed mRNA transcript of IGFBP-rP1 in these PC-3-rP1 clones. A 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay showed growth rate was significantly lower in PC-3-rP1 cells than in the nontransfected control. In addition, the medium obtained from PC-3-rP1 cells reduced the growth rate in both PC-3-rP1 and control PC-3 cells. A soft agar colony-forming assay revealed that colony formation was markedly decreased in PC-3-rP1 cells. The number of apoptotic cells and
caspase-3
expression were increased in the PC-3-rP1 cells as compared with control PC-3 cells. This is the first study that suggests inactivation of IGFBP-rP1 is through CpG methylation, and tumor-suppressive activity of IGFBP-rP1 is through induction of apoptosis in an IGF-I independent manner in
prostate cancer
.
...
PMID:Restoration of insulin-like growth factor binding protein-related protein 1 has a tumor-suppressive activity through induction of apoptosis in human prostate cancer. 1463 96
Pathogenesis of
prostate cancer
is paralleled by aberrant transcriptional regulation which involves gene silencing by histone deacetylases. In cancer cells, inhibitors of histone deacetylases such as valproic acid can act as differentiation agents which relieve pro-apoptotic factors from transcriptional repression. We investigated the potential of the well-tolerated anticonvulsant valproic acid in
prostate cancer
cell line LNCaP and analyzed the activation of pro-apoptotic factors and resulting apoptosis. We used real time RT-PCR to quantify the mRNA expression of prostate-specific antigen, prostate-derived Ets transcription factor, tissue inhibitor of matrix metalloproteinase-3 and insulin-like growth factor binding protein-3. An automated sandwich-ELISA was used to measure secretion of prostate-specific antigen in conditioned cell culture media of LNCaP
prostate cancer
cells. Apoptotic cells were detected cytochemically and by applying immunocytochemistry. Activity of histone deacetylases in nuclear extracts was measured with a colorimetric assay kit. Valproic acid treatment caused a marked inhibition of histone deacetylases activity. Expression of prostate-derived Ets transcription factor and consequently prostate-specific antigen were down-regulated to basal levels in LNCaP cells. Pro-apoptotic factor
caspase-3
, tissue inhibitor of matrix metalloproteinase-3 and insulin-like growth factor binding protein-3 were up-regulated resulting in apoptosis of tumor cells. Valproic acid mediates marked effects on the expression of genes relevant in proliferation and apoptosis. Our study provides strong evidence that
prostate cancer
may benefit particularly from anti-proliferative stimuli from this well established drug.
...
PMID:Expressional changes after histone deacetylase inhibition by valproic acid in LNCaP human prostate cancer cells. 1465 37
Signal transducers and activators of transcription (STAT) were originally discovered as components of cytokine signal transduction pathways. Persistent activation of one STAT, STAT3, is a common feature of
prostate cancer
. Activated STAT3 was found in pathology specimens obtained from prostatectomy in the cancerous areas but not in the normal margins. Because the activation of STAT3 is mediated by the action of an upstream Janus kinase (JAK) kinase, usually JAK1 or JAK2, the activation step for STAT3 might itself be a target for therapy in
prostate cancer
. However, the redundancy of upstream kinases may make this strategy unreliable for therapy. To develop molecular targets for
prostate cancer
treatment, JAK kinase and STAT3 inhibition of two
prostate cancer
lines were compared. DU145 and NRP-154 cells were treated with JAK kinase inhibitors, analyzed for onset of apoptosis, and measured by annexin V binding and propidium iodide uptake. Activation of caspases in the cells was determined by measuring cleaved
caspase-3
following treatment. For determining the effect on mitochondrial membrane depolarization that accompanies apoptosis, the fluorescent dye JC-1 was used. STAT3 was specifically inhibited by transfecting either a dominant-negative (DN) STAT3 plasmid or antisense STAT3 oligonucleotides into the cells. To look for reduction in STAT3 levels within cells, fixed and permeabilized
prostate cancer
cells were stained with antibody to STAT3. We found that more than one JAK kinase is involved in STAT3 activation in
prostate cancer
lines. AG490 (JAK2 specific) induced apoptosis in DU145 but not in NRP-154
prostate cancer
lines, whereas piceatannol (JAK1 specific) induced apoptosis in NRP-154 but not in DU145 cells. Next, we demonstrated efficacy of specific STAT3 inhibitors in
prostate cancer
lines. Both induction of apoptosis and reduction in intracellular STAT3 protein were observed following treatment with antisense STAT3 oligonucleotides, while transfection of a DN-STAT3 plasmid into both
prostate cancer
cell lines resulted in loss of viability and onset of apoptosis. We conclude that STAT3-specific inhibitors, rather than JAK kinase-specific inhibitors, should be more useful therapeutically in treating androgen-resistant
prostate cancer
and that STAT3 is an appropriate target in the treatment of
prostate cancer
.
...
PMID:Signal transducer and activator of transcription 3 (STAT3) activation in prostate cancer: Direct STAT3 inhibition induces apoptosis in prostate cancer lines. 1474 71
Recent clinical trials have documented that selenium significantly reduces the incidence of clinical
prostate cancer
. However, nothing is clearly known about the underlying molecular mechanisms by which selenium exerts its anti-cancer effect. This report provides evidence that selenium at micro-molar concentrations induces rapid apoptotic death in human
prostate cancer
cells, but not in normal prostate epithelial cells. Apoptosis involves activation of
caspase 3
which plays a critical role in the cell death process. Interestingly, the apoptosis-inducing effect of selenium in
prostate cancer
cells is substantially alleviated by the 5-lipoxygenase metabolites, 5(S)-HETE and its dehydrogenated derivative 5-oxoETE, but not by metabolites of 12-lipoxygenase (12(S)-HETE) or 15-lipoxygenase (15(S)-HETE). Apoptosis is also prevented by their precursor, arachidonic acid, an omega-6, polyunsaturated fatty acid, presumably by metabolic conversion through the 5-lipoxygenase pathway. These results indicate that selenium's anticancer effect may involve induction of apoptosis specifically in
prostate cancer
cells sparing normal prostate epithelial cells, and that 5-lipoxygenase may be a molecular target of selenium's anticancer action. The present report warrants that care should be taken about high intake of dietary fat containing arachidonic acid or its precursor fatty acids when selenium is used for the management of
prostate cancer
, and suggests that a combination of selenium and 5-lipoxygenase inhibitors may be a more effective regimen for
prostate cancer
control.
...
PMID:Rapid induction of apoptosis in prostate cancer cells by selenium: reversal by metabolites of arachidonate 5-lipoxygenase. 1497 47
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