Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

---

Query: UNIPROT:P42574 (caspase-3)
45,978 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

RNA interference (RNAi) is used as a reverse-genetic tool to examine functions of a gene in different cellular processes including apoptosis. As key cellular proteins are inactivated during apoptosis, and as RNAi requires cooperation of many cellular proteins, we examined whether DNA vector-based RNAi would continue to function during apoptosis. The short hairpin RNA transcribed from the DNA vector is processed by Dicer-1 to form small interfering RNA that is incorporated in the RNA-induced silencing complex (RISC) to guide a sequence-specific silencing of the target mRNA. We report here that DNA vector-based RNAi of three different genes, namely poly(ADP-ribose) polymerase-1, p14(ARF) and lamin A/C are abrogated during apoptosis. The failure of DNA vector-based RNAi was not at the level of Ago-2 or RISC-mediated step of RNAi but due to catalytic inactivation of Dicer-1 on specific cleavage at the STTD(1476) and CGVD(1538) sites within its RNase IIIa domain. Using multiple approaches, caspase-3 was identified as the major caspase responsible for the cleavage and inactivation of Dicer-1. As Dicer-1 is also the common endonuclease required for formation of microRNA (miRNA) in mammalian cells, we observed decreased levels of mature forms of miR-16, miR-21 and let-7a. Our results suggest a role for apoptotic cleavage and inactivation of Dicer-1 in controlling apoptotic events through altered availability of miRNA.
...
PMID:Abrogation of DNA vector-based RNAi during apoptosis in mammalian cells due to caspase-mediated cleavage and inactivation of Dicer-1. 1922 43

Vulvar carcinoma is a rare female genital neoplasia. Radical surgery, which has been the standard treatment approach, is often accompanied by considerable morbidity. To reduce the incidence of complications there has been a movement toward individualised therapy and less radical surgery. Associated with this, new tumour markers that could serve as prognostic indicators would be of considerable value to guide treatment decision. In this review, a brief update of molecular pathological markers of vulvar carcinomas is provided, and their impact as prognostic markers is addressed. p16, p21, p14, p27, cyclin A, cyclin D1, p53, vascular endothelial growth factor (VEGF), transforming growth factor alpha, HER-2 and epidermal growth factor receptor (EGFR) have been found to be important in the pathogenesis and/or progression of vulvar carcinomas. Furthermore, human papillomavirus, p16, p21, p14, p53, VEGF, CD44v3, CD44v6, CD44v4, CD44v9, CD44v10, HER-2, EGFR, matrix metalloproteinase-12, caspase 3, Bcl-2 and nm23-H1 have been correlated to clinical outcome of patients with vulvar carcinomas. However, due to the relative small number of studies reported for each molecular pathological marker, and the relative small number of vulvar carcinomas included and the lack of multivariate analysis in the majority of these studies, no conclusion regarding the prognostic value of these markers can be drawn. Therefore, the investigated markers have not yet earned a place in standard clinical diagnostics or treatment, and further studies are needed to clarify the clinical value of these markers.
...
PMID:A review of molecular pathological markers in vulvar carcinoma: lack of application in clinical practice. 1925 52

To determine the effect of a vascular endothelial growth factor receptor 2 tyrosine kinase (VEGFR2) inhibitor on intravitreous neovascularization (IVNV), endothelial tip cell filopodia, and intraretinal vascularization in a rat model of retinopathy of prematurity (ROP). Within 4h of birth, newborn Sprague-Dawley rat pups and their mothers were cycled between 50% and 10% oxygen daily until postnatal day (p)12. Pups were given intravitreous injections of VEGFR2 inhibitor, SU5416, or control (dimethyl sulfoxide, DMSO) and returned to oxygen cycling until p14, then placed into room air. Intravitreous neovascularization (IVNV), avascular/total retinal areas, and endothelial tip cell filopodial number and length were determined in lectin-labeled neurosensory retinal flat mounts. Cryosections or fresh tissue were analyzed for phospho-VEGFR1, phospho-VEGFR2, activated caspase-3, or phospho-beta3 integrin. Human umbilical venous (HUVECs) and human choroidal endothelial cells (ECs) were treated with VEGFR2 inhibitor to determine effect on VEGFR2 phosphorylation and on directed EC migration toward a VEGF gradient. Filopodial length and number of migrated ECs were also measured. Compared to control, the VEGFR2 inhibitor reduced VEGFR2 phosphorylation in HUVECs in vitro and clock hours and areas of IVNV but not percent avascular retina in vivo. Filopodial length and number of filopodia/EC tip cell were reduced in retinal flat mounts at doses that inhibited IVNV, whereas at lower doses, only a reduction in filopodial length/EC tip cell was found. There was no difference in phosphorylated beta3 integrin and cleaved caspase-3 labeling in VEGFR2 inhibitor-treated compared to control in vivo. Doses of the VEGFR2 inhibitor that reduced filopodial length and number of filopodia/migrating EC corresponded to reduced EC migration in in vitro models. VEGFR2 inhibitor reduced IVNV and filopodial number and length/EC tip cell without interfering with intraretinal vascularization. Reducing the number and length of filopodia/endothelial tip cell may reduce guidance cues for endothelial cells to migrate into the vitreous without interfering with migration into the retina toward a VEGF gradient.
...
PMID:Reduction in endothelial tip cell filopodia corresponds to reduced intravitreous but not intraretinal vascularization in a model of ROP. 1957 14

Induction of cell death by p14(ARF) is mediated through a Bax/Bak-dependent mitochondrial apoptosis pathway. To investigate the upstream signaling events required for the activation of Bax and/or Bak and to determine the functional impact of de-regulated cell cycle restriction point control in this context, we genetically dissected the impact of BH3-only proteins and the role of the cyclin-dependent kinase (cdk) inhibitor p21(CDKN1). Using isogenic HCT116 colorectal cancer cells, either wild-type or homozygously deleted for the BH3-only protein Puma/bbc3 and/or p21(CDKN1) or p53-reconstituted DU145 prostate cancer cells, we show that p14(ARF)-induced apoptosis is attenuated in the absence of Puma. Upon expression of p14(ARF) in HCT116 cells, Puma is rapidly induced at both the mRNA and protein level. Puma-proficient HCT116 cells undergo apoptotic (nuclear) DNA fragmentation, which is preceded by the N-terminal conformational change of Bax, the breakdown of the mitochondrial membrane potential, and induction of caspase-9 (LEHD)-like and caspase-3/7 (DEVD)-like activities. In contrast, p14(ARF)-induced apoptosis is markedly attenuated in isogenic HCT116 cells bi-allelically deleted for puma. The sensitivity of Puma-deficient cells to p14(ARF)-induced apoptosis is fully restored by functional reconstitution of Puma using a conditional adenoviral expression vector. Notably, the concomitant deletion of p21(CDKN1) strongly enhances p14(ARF)-induced apoptosis in Puma-proficient cells, but not in isogenic Puma-deficient cells. These results indicate that p14(ARF)-induced mitochondrial apoptosis critically depends on the BH3-only protein Puma. In the presence of a functional p53/Puma/Bax-signaling axis, p14(ARF)-triggered apoptosis is enhanced by loss of p21(CDKN1)-mediated cell cycle checkpoint control.
...
PMID:Systematic genetic dissection of p14ARF-mediated mitochondrial cell death signaling reveals a key role for p21CDKN1 and the BH3-only protein Puma/bbc3. 2041 47

Prognosis for patients with glioblastoma multiforme (GBM) is poor. Inhibitors of histone deacetylases (HDACi) like trichostatin A (TSA) are promising alternatives to conventional treatment. Deficient tumor suppressor functions, such as TP53 mutations and p14(ARF)/p16(INK4a) deletions, are characteristic for GBM and can cause resistance to DNA damaging agents such as cisplatin and to HDACi like TSA. The type II tumor suppressor Inhibitor of growth 1 (ING1) is involved in DNA damage response and histone modification. We have previously shown that ING1 is downregulated in GBM and involved in glioma-induced angiogenesis and in cisplatin-induced apoptosis in malignant glioma cells. Hence, the goal of our present study was to investigate whether TSA affects ING1 protein expression and also whether modulating ING1 levels affects TSA-induced apoptosis in malignant glioma cells that contain deficient p53 function and inactive pl4(ARF)/p16(INK4a) signaling. If so, we asked, which apoptotic pathway might be the major mediator beyond this interaction. To test whether ING1 proteins function in TSA-induced apoptosis in GBM, we analyzed TSA effects in LN229 GBM cells, which harbor TP53 mutations and INK4a deletion, following ING1 knockdown by siRNA. Expression of ING1, acetylated core histones H3 and H4, and the proapoptotic proteins caspase 3 and Fas-associated death domain (FADD) was determined by Western blotting. Percentages of apoptotic cells were obtained by flow cytometry. TSA induced the major ING1 isoform p33(ING1b) and increased levels of both histone acetylation and apoptosis in LN229 cells. ING1 knockdown cells revealed marked resistance to TSA-induced apoptosis, impairment of caspase 3 activation, and suppression of FADD. The data suggest that ING1 contributes to TSA-induced apoptosis in GBM cells with deficient p53 and p14(ARF)/p16(INK4a) functions, possibly by regulating FADD/caspase 3 signaling.
...
PMID:The inhibitor of growth 1 (ING1) is involved in trichostatin A-induced apoptosis and caspase 3 signaling in p53-deficient glioblastoma cells. 2068 6

MYCN amplification is a major biomarker of poor prognosis, occurring in 25-30% of neuroblastomas. MYCN has contradictory roles in promoting cell growth and sensitizing cells to apoptosis. We have recently shown that p53 is a direct transcriptional target of MYCN in neuroblastoma and that p53-mediated apoptosis may be an important mechanism of MYCN-induced apoptosis. Although p53 mutations are rare in neuroblastoma at diagnosis, the p53/MDM2/p14(ARF) pathway is often inactivated through MDM2 amplification or p14(ARF) inactivation. We hypothesized that reactivation of p53 by inhibition of its negative regulator MDM2, using the MDM2-p53 antagonists Nutlin-3 and MI-63, will result in p53-mediated growth arrest and apoptosis especially in MYCN-amplified cells. Using the SHEP Tet21N MYCN-regulatable system, MYCN(-) cells were more resistant to both Nutlin-3 and MI-63 mediated growth inhibition and apoptosis compared with MYCN(+) cells and siRNA-mediated knockdown of MYCN in four MYCN-amplified cell lines resulted in decreased p53 expression and activation, as well as decreased levels of apoptosis following treatment with MDM2-p53 antagonists. In a panel of 18 neuroblastoma cell lines treated with Nutlin-3 and MI-63, the subset amplified for MYCN had a significantly lower mean GI(50) value (50% growth inhibition) and increased caspase 3/7 activity compared with the non-MYCN-amplified group of cell lines, but p53 mutant cell lines were resistant to the antagonists regardless of MYCN status. We conclude that amplification or overexpression of MYCN sensitizes neuroblastoma cell lines with wild-type p53 to MDM2-p53 antagonists and that these compounds may therefore be particularly effective in treating high-risk MYCN-amplified disease.
...
PMID:MYCN sensitizes neuroblastoma to the MDM2-p53 antagonists Nutlin-3 and MI-63. 2172 57

The p14(ARF) tumor suppressor triggers cell death or cell cycle arrest upon oncogenic stress. In MCF-7 breast carcinoma cells, expression of the tumor suppressor gene p14(ARF) fails to trigger apoptosis but induces an arrest in the G1 and, to a lesser extent, in the G2 phase in the cell division cycle. Here, inhibition of cell cycle arrest resulted in apoptosis induction in caspase-3 proficient MCF-7 cells upon expression of p14(ARF) . This occurred in the absence of S-phase progression or mitotic entry. In contrast, syngeneic, caspase-3-deficient MCF-7 cells remained entirely resistant to p14(ARF) -induced apoptosis. Thus, cell cycle checkpoint abrogation overcomes resistance to p14(ARF) -induced cell death and promotes cell death via a caspase-3-dependent pathway. Cell death coincided with dissipation of the mitochondrial membrane potential, release of cytochrome c, and was inhibitable by pan-caspase inhibitors and the caspase-3/7 inhibitor zDEVD-fmk. Of note, mitochondrial events of apoptosis execution depended entirely on caspase-3 proficiency indicating that caspase-3 either acts "up-stream" of the mitochondria in a "non-canonical" pathway or mediates a mitochondrial feedback loop to amplify the apoptotic caspase signal in p14(ARF) -induced stress signaling.
...
PMID:p14ARF induces apoptosis via an entirely caspase-3-dependent mitochondrial amplification loop. 2368 72

All-trans retinoic acid (ATRA), the most biologically active metabolite of vitamin A, has been extensively studied for the prevention and treatment of cancer; however, the underlying mechanism of its anti-cancer potential is still unclear. Here we found that ATRA induces apoptosis in p53-positive HepG2 cells, but not in p53-negative Hep3B cells. For this effect, ATRA activated p14 expression via promoter hypomethylation, resulting in ubiquitin-dependent degradation of mouse double minute 2 (MDM2) and subsequent stabilization of p53. The potential of ATRA to stabilize p53 was almost completely abolished by knock-down of p14 in HepG2 cells and was not observed in p14-negative A549 cells. Upregulation of p14 also abolished the self-regulatory potential of p53 to repress p14 expression via DNA methylation and transcriptionally activate MDM2 expression. The accumulated p53 then activated several apoptosis-related molecules, including Bax, PUMA, caspase-9, Bid, caspase-8, caspase-3, and PARP. Ectopic expression of DNA methyltransferase 1 almost completely abolished the potential of ATRA to activate the p14-MDM2-p53 pathway and induce p53-dependent apoptosis. Therefore, we conclude that ATRA induces p14 promoter hypomethylation to trigger apoptosis.
...
PMID:All-trans retinoic acid induces p53-depenent apoptosis in human hepatocytes by activating p14 expression via promoter hypomethylation. 2582 71

Neuroblastoma is a predominantly p53 wild-type (wt) tumour and MDM2-p53 antagonists offer a novel therapeutic strategy for neuroblastoma patients. RG7388 (Roche) is currently undergoing early phase clinical evaluation in adults. This study assessed the efficacy of RG7388 as a single-agent and in combination with chemotherapies currently used to treat neuroblastoma in a panel of neuroblastoma cell lines. RG7388 GI50 concentrations were determined in 21 p53-wt and mutant neuroblastoma cell lines of varying MYCN, MDM2 and p14(ARF) status, together with MYCN-regulatable Tet21N cells. The primary determinant of response was the presence of wt p53, and overall there was a >200-fold difference in RG7388 GI50 concentrations for p53-wt versus mutant cell lines. Tet21N MYCN+ cells were significantly more sensitive to RG7388 compared with MYCN- cells. Using median-effect analysis in 5 p53-wt neuroblastoma cell lines, selected combinations of RG7388 with cisplatin, doxorubicin, topotecan, temozolomide and busulfan were synergistic. Furthermore, combination treatments led to increased apoptosis, as evident by higher caspase-3/7 activity compared to either agent alone. These data show that RG7388 is highly potent against p53-wt neuroblastoma cells, and strongly supports its further evaluation as a novel therapy for patients with high-risk neuroblastoma and wt p53 to potentially improve survival and/or reduce toxicity.
...
PMID:Pre-clinical evaluation of the MDM2-p53 antagonist RG7388 alone and in combination with chemotherapy in neuroblastoma. 2584

All-trans retinoic acid (ATRA), the most biologically active metabolite of vitamin A, is known to activate p14 expression via promoter hypermethylation to induce p53-dependent apoptosis in human hepatocytes. In this study, we found that the oncogenic hepatitis B virus (HBV) X protein (HBx) of HBV, derived from both overexpression and 1.2-mer replicon systems, suppresses ATRA-induced apoptosis in p53-positive human hepatocytes. For this effect, HBx upregulated both protein and enzyme activity levels of DNA methyltransferase 1, 3a and 3b, in the presence of ATRA and thereby inhibited p14 expression via promoter hypermethylation, resulting in inactivation of the p14-mouse double minute 2 pathway and subsequent downregulation of p53 levels. As a result, HBx was able to impair the potential of ATRA to activate apoptosis-related molecules, including Bax, p53-upregulated modulator of apoptosis, caspase-9, caspase-3 and poly (ADP-ribose) polymerase. In conclusion, the present study provides a new oncogenic action mechanism of HBx, namely by suppressing the anticancer potential of ATRA to induce p53-dependent apoptosis in HBV-infected hepatocytes.
...
PMID:Hepatitis B virus X protein suppresses all-trans retinoic acid-induced apoptosis in human hepatocytes by repressing p14 expression via DNA methylation. 2906 87


<< Previous 1 2 3 Next >>

---