Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.22.56 (caspase-3)
 35,750 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Survivin, an inhibitor of apoptosis protein, deserves attention as a selective target for cancer therapy because it lacks expression in differentiated adult tissues but is expressed in a variety of human tumors. We designed 20-mer phosphorothioate antisense oligonucleotides targeting different regions of survivin mRNA and investigated their ability to down-regulate survivin mRNA and induce apoptosis in the lung adenocarcinoma cell line A549. Oligonucleotide 4003, which targets nucleotides 23-251 of survivin mRNA, was identified as the most potent compound. As measured by real-time PCR, 4003 down-regulated survivin mRNA in a dose-dependent manner with an IC50 of 200 nM. Its maximum effect was achieved at a concentration of 400 nM, at which mRNA was down-regulated by 70%. As revealed by increased caspase-3-like protease activity, nuclear condensation and fragmentation, and trypan blue uptake, treatment with 4003 induced apoptosis and sensitized tumor cells to the chemotherapeutic agent etoposide. Oligonucleotide 4003 did not reduce the viability of normal blood leukocytes with marginal levels of survivin mRNA.
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PMID:A novel antisense oligonucleotide targeting survivin expression induces apoptosis and sensitizes lung cancer cells to chemotherapy. 1085 Apr 18

Fibroblast growth factor-2 (FGF-2) is involved as an autocrine growth factor in the autonomous proliferation of glioma cells. To develop a new strategy for treating patients with glioma, we studied the effect on human glioma cells of a 16-mer oligopeptide with conformational similarity to the putative receptor-binding domain of FGF-2. A synthesized oligonucleotide was assessed its receptor-binding activity by BIAcore instrument. Its biological effect on glioma cell lines was examined in vitro by MTT assay. The peptide suppressed the in vitro growth of human glioma cells U87MG, T98G and U251MG cells, but not of A431 cells whose growth is not dependent on FGF-2. Apoptotic bodies were noted after 24-h incubation in the presence of the peptide; Ac-YVAD-CHO, a caspase-3 inhibitor, suppressed apoptosis. Furthermore, we examined the modulation of the cytotoxic effect of anticancer drugs by the oligopeptide. The addition of this oligopeptide to the chemotherapeutic agents CDDP, ACNU and VP16 had additive effects in vitro. These results suggest that the pathway of the FGF-2 autocrine loop through the FGF receptor plays an important role in the proliferation of glioma cells. New drugs targeting this loop may be highly effective in treating FGF-2-dependent tumors. Our results suggest that its addition to the therapeutic arsenal may lead to improved treatment regimens for patients with FGF-2-dependent tumors.
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PMID:In vitro growth suppression of human glioma cells by a 16-mer oligopeptide: a potential new treatment modality for malignant glioma. 1282 20

Re-expression of the death-signalling p75 neurotrophin receptor (p75NTR) is associated with injury and neurodegeneration in the adult nervous system. The induction of p75NTR expression in mature degenerating spinal motor neurons of humans and transgenic mice with amyotrophic lateral sclerosis (ALS) suggests a role of p75NTR in the progression of motor neuron disease (MND). In this study, we designed, synthesized and evaluated novel antisense peptide nucleic acid (PNA) constructs targeting p75NTR as a potential gene knockdown therapeutic strategy for ALS. An 11-mer antisense PNA directed at the initiation codon, but not downstream gene sequences, dose-dependently inhibited p75NTR expression and death-signalling by nerve growth factor (NGF) in Schwann cell cultures. Antisense phosphorothioate oligonucleotide (PS-ODN) sequences used for comparison failed to confer such inhibitory activity. Systemic intraperitoneal administration of this antisense PNA to mutant superoxide dismutase 1 (SOD1G93A) transgenic mice significantly delayed locomotor impairment and mortality compared with mice injected with nonsense or scrambled PNA sequences. Reductions in p75NTR expression and subsequent caspase-3 activation in spinal cords were consistent with increased survival in antisense PNA-treated mice. The uptake of fluorescent-labelled antisense PNA in the nervous system of transgenic mice was also confirmed. This study suggests that p75NTR may be a promising antisense target in the treatment of ALS.
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PMID:Antisense peptide nucleic acid-mediated knockdown of the p75 neurotrophin receptor delays motor neuron disease in mutant SOD1 transgenic mice. 1453 57

MicroRNAs (miRNAs) are abundant small regulatory RNAs with multiple roles in cell fate determination. The processes regulating cellular miRNA levels are still unclear and experimental oligonucleotide tools to readily mimic their effects are not yet available. Here, we report that thapsigargin-induced intracellular Ca(++) release suppressed pre-miR-181a levels in human promegakaryotic Meg-01 cells, induced differentiation-associated nuclear endoreduplication and caspase-3 activation and replaced the acetylcholinesterase 3' splice variant AChE-S with AChE-R. AChE, PKC and PKA inhibitors all attenuated the pre-miR-181a decline and the induced differentiation. AChmiON, a synthetic 23-mer 2'-oxymethylated oligonucleotide mimicking the miR-181a sequence, blocked the calcium-induced differentiation while elevating cellular pre-miR-181a levels and inducing DNA fragmentation and cell death. Moreover, when added to RW 264.7 macrophages, AChmiON at 100 nM induced nitric oxide production with efficiency close to that of bacterial endotoxin, demonstrating physiologically relevant activities also in blood-born monocytes/macrophages. The stress-induced modulation of hematopoietic miR-181a levels through AChE, PKC and PKA cascade(s) suggests using miRNA mimics for diverting the fate of hematopoietic tumor cells towards differentiation and/or apoptosis.
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PMID:MicroRNA modulation of megakaryoblast fate involves cholinergic signaling. 1624 78

Thyroid hormone (TH) controlled gene expression profiles have been studied in the tail, hind limb and brain tissues during TH-induced and spontaneous Xenopus laevis metamorphosis. Amplified cRNA probes mixed with a universal standard were hybridized to a set of 21,807-sense strand 60-mer oligonucleotides on each slide representing the entries in X. laevis UniGene Build 48. Most of the up-regulated genes in hind limb and brain are the same. This reflects in part the fact that the initial response to TH induction in both tissues is cell proliferation. A large number of up-regulated genes in the limb and brain programs encode common components of the cell cycle, DNA and RNA metabolism, transcription and translation. Notch is one of the few genes that is differentially expressed exclusively in the brain in the first 48 h of TH induction studied in these experiments. The TH-induced gene expression changes in the tail are different from the limb and brain programs. Distinct muscle and fibroblast programs were identified in the tail. Dying muscle fibers in tail (marked by active caspase-3) up-regulate a group of genes that include proteolytic enzymes. At the climax of metamorphosis, tail muscle down-regulates more than half of the genes that encode the glycolytic enzymes in the cytoplasm and the tricarboxylic acid pathway and all five complexes of the electron transport system in mitochondria. These changes in gene expression precede the activation of caspase-3. Some of these same energy metabolism-related genes are up-regulated in the limb and brain programs by TH. A prominent feature of the tail fibroblasts is the down-regulation of several collagen and other extra cellular matrix genes and the up-regulation of hydrolytic enzymes that are responsible for dissolving the notochord and resorbing the tail.
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PMID:Gene expression changes at metamorphosis induced by thyroid hormone in Xenopus laevis tadpoles. 1645 81

Growth arrest-specific protein 6 (gas6) activity is mediated through the receptor tyrosine kinase family members Axl, Rse, and Mer, all of which are expressed in human oligodendrocytes. In this study, we examined whether recombinant human (rh) gas6 protects oligodendrocytes from growth factor (insulin) withdrawal or tumor necrosis factor-alpha (TNFalpha) cytotoxicity. In addition, we examined whether the effect was caspase-dependent, which receptor mediated the protective effect, and whether survival required Akt1 activation. Oligodendrocyte viability was assessed by O4 staining and terminal deoxynucleotidyl transferase-mediated biotinylated UTP nick end labeling. Addition of rhgas6 to insulin-depleted cultures resulted in a significant increase in oligodendrocyte viability. Rhgas6 and caspase inhibitors also reduced active caspase-3 immunoreactivity relative to TNFalpha-only-treated cultures. In cultures treated with TNFalpha (100 ng/ml), the oligodendrocyte survival rate was 18% compared with cultures treated with TNFalpha and rhgas6 (64%) or the caspase inhibitors IETD-fmk [z-Ile-Glu(OMe)-Thr-Asp(OMe)-fluoromethyl ketone] (65%) and zVAD-fmk (N-benzyloxycarbonyl-Val-Ala-Asp-fluoromethyl ketone) (63%). Increased phosphoAkt (Ser473) immunoreactivity was detected 15 min after administration of gas6 and TNFalpha to oligodendrocyte cultures but not in TNFalpha-treated cultures. The gas6 protective effect was abrogated by the Axl decoy receptor Axl-Fc, by the phosphatidylinositol 3 (PI3) kinase inhibitor LY294002 [2-(4-morpholinyl)-8-phenyl-1(4H)-benzopyran-4-one], and in Akt1(-/-) oligodendrocytes. Oligodendrocyte cultures established from wild-type and Rse(-/-) mice, but not from Axl(-/-) mice, were also protected from TNFalpha-induced cell death when maintained in rhgas6. We conclude that gas6 signaling through the Axl receptor and the PI3 kinase/Akt1 survival pathway protects oligodendrocytes from growth factor withdrawal and TNFalpha-mediated cell death.
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PMID:Gas6/Axl signaling activates the phosphatidylinositol 3-kinase/Akt1 survival pathway to protect oligodendrocytes from tumor necrosis factor alpha-induced apoptosis. 1672 20

The X-chromosome-linked inhibitor of the apoptosis protein (XIAP) is known to be an inhibitory factor for caspase-3. The aim of our study was to see whether radiation-induced apoptosis is enhanced by RNA interference targeting the XIAP through an elevation of caspase-3 activity, and whether the effect of XIAP depression depends on the p53 status of cancer cells. Two types of transformed human cultured non-small cell lung cancer cells (H1299) were used: wild-type p53-transfected cells (H1299/wtp53) and mutated p53-transfected cells (H1299/mp53). When 21-mer siRNA targeting XIAP (XIAP-siRNA) was transfected into these cells using liposomes, a suppression of the constitutive XIAP protein expression was observed. XIAP-siRNA enhanced radiation sensitivity in H1299/wtp53 and in H1299/mp53 cells and was very effective in H1299/mp53 cells. Radiation-induced apoptosis and the activation of caspase-3 were more elevated by XIAP-siRNA in the H1299/mp53 cells than in H1299/ wtp53. These results suggest that XIAP-siRNA is a possible candidate for a radiation sensitizer in cancer radiotherapy, especially in cells with mutated p53.
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PMID:Effective enhancement of X-ray-induced apoptosis in human cancer cells with mutated p53 by siRNA targeting XIAP. 1857 18

Molecular and cellular imaging of atherosclerosis has garnered more interest at the beginning of the 21st century, with aims to image in vivo biological properties of plaque lesions. Apoptosis seems an attractive target for the diagnosis of vulnerable atherosclerotic plaques prone to a thrombotic event. The aim of the present work was to screen for apoptosis peptide binders by phage display with the final purpose to detect apoptotic cells in atherosclerotic plaques by magnetic resonance imaging (MRI). A phosphatidylserine-specific peptide identified by phage display was thus used to design an MRI contrast agent (CA), which was evaluated as a potential in vivo reporter of apoptotic cells. A library of linear 6-mer random peptides was screened in vitro against immobilized phosphatidylserine. Phage DNA was isolated and sequenced, and the affinity of peptides for phosphatidylserine was evaluated by enzyme-linked immunosorbent assay. The phosphatidylserine-specific peptide and its scrambled homologue were attached to a linker and conjugated to DTPA-isothiocyanate. The products were purified by dialysis and by column chromatography and complexed with gadolinium chloride. After their evaluation using apoptotic cells and a mouse model of liver apoptosis, the phosphatidylserine-targeted CA was used to image atherosclerotic lesions on ApoE(-/-) transgenic mice. Apoptotic cells were detected on liver and aorta specimens by the immunostaining of phosphatidylserine and of active caspase-3. Sequencing of the phage genome highlighted nine different peptides. Their alignment with amino acid sequences of relevant proteins revealed a frequent homology with Ca2+ channels, reminiscent of the function of annexins. Alignment with molecules involved in apoptosis provides a direct correlation between peptide selection and utility. The in vivo MRI studies performed at 4.7 T provide proof of concept that apoptosis-related pathologies could be diagnosed by MRI with a low molecular weight paramagnetic agent. The new CA could have real potential in the diagnosis and therapy monitoring of atherosclerotic disease and of other apoptosis-associated pathologies, such as cancer, ischemia, chronic inflammation, autoimmune disorders, transplant rejection, neurodegenerative disorders, and diabetes mellitus. The phage display-derived peptide could also play a potential therapeutic role through anticoagulant activity by mimicking the role of annexin V, the endogenous ligand of phosphatidylserine.
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PMID:Peptidic targeting of phosphatidylserine for the MRI detection of apoptosis in atherosclerotic plaques. 1974 79

Parkinson's disease (PD) is a chronic progressive neurological disorder with an increasing incidence in the aging population. Neuroprotective and/or neuroregenerative strategies remain critical in the treatment of this increasingly prevalent disease. Prosaposin is a neurotrophic factor whose neurotrophic activity is attributed to a stretch of 12 amino acids located at the N-terminal region of saposin C. The present study was performed to investigate the protective effect and mechanism of action of a prosaposin-derived 18-mer peptide (PS18: LSELIINNATEELLIKGL) in Parkinson's disease models. We used 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) or 1-methyl-4-phenylpyridinium ion (MPP(+))-induced dopaminergic neurotoxicity in C57BL/6J mice or SH-SY5Y cells and explored the protective effect and mechanisms of action of PS18 on dopaminergic neurons. Treatment with 2.0mg/kg PS18 significantly improved behavioral deficits, enhanced the survival of tyrosine hydroxylase-positive neurons, and decreased the activity of astrocytes in the substantia nigra and striatum in MPTP-induced PD model mice. In vitro, a Cell Counting Kit-8 assay and Hoechst 33258 staining revealed that co-treatment with 300ng/mL PS18 and 5mM MPP(+) protected against MPP(+)-induced nuclear morphological changes and attenuated cell death induced by MPP(+). We also found that PS18-FAM entered the cells, and the retention time of PS18-FAM in the cytoplasm of MPP(+)-treated cells was shorter than that of untreated cells. In addition, PS18 showed protection from MPP(+)/MPTP-induced apoptosis in the SH-SY5Y cells and dopaminergic neurons in the PD model mice via suppression of the c-Jun N-terminal kinase/c-Jun pathway; upregulation of Bcl-2; downregulation of BAX, attenuating mitochondrial damage; and inhibition of caspase-3. These findings suggest that PS18 may provide a valuable therapeutic strategy for the treatment of progressive neurodegenerative diseases such as PD.
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PMID:Attenuation of MPTP/MPP(+) toxicity in vivo and in vitro by an 18-mer peptide derived from prosaposin. 2332 39

Vascular smooth muscle cell (VSMC) apoptosis plays an important role in vascular remodeling and atherosclerotic plaque instability. Oxidative stress in diseased vessels promotes VSMC apoptosis in part by activating the c-Jun N-terminal kinase (JNK) pathway, which has been identified as a molecular target of miR-92a in macrophages. Here, we examined the expression and biological activity of miR-92a in VSMC. Quiescent VSMC exhibited a low basal expression of miR-92a, which was positively regulated by serum stimulation and negatively regulated by H2O2. Overexpression of miR-92a decreased H2O2-induced VSMC apoptosis as indicated by TUNEL assay and cleaved caspase-3 protein levels. Using 3'UTR-reporter assay, we found that miR-92a overexpression led to suppression of both mitogen-activated protein kinase kinase 4 (MKK4)- and JNK1-dependent luciferase activity. We also found that 10 mer seed match between miRNA:mRNA pair is more efficient than 8 mer seed match for us to identify authentic miRNA target. Protein levels of active phospho-JNK and phospho-c-Jun, downstream targets of the MKK4-JNK1 pathway, were also decreased by overexpressing miR-92a in VSMC under oxidative stress. Consistent with these findings, overexpression of MKK4 reversed the anti-apoptotic effects of miR-92a in oxidatively stressed VSMC. In conclusion, miR-92a overexpression inhibits H2O2-induced VSMC apoptosis by directly targeting the MKK4-JNK1 pathway.
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PMID:miR-92a inhibits vascular smooth muscle cell apoptosis: role of the MKK4-JNK pathway. 2470


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