Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0027819 (neuroblastoma)
 27,800 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have previously defined a homozygously deleted region at chromosome 1p36.2-p36.3 in human neuroblastoma cell lines, NB-1 and NB-C201, and identified six genes including DFF45/ICAD within this region. In this study, we found that NB-C201 cells are much more resistant to various genotoxic stresses such as cisplatin (CDDP) than CHP134 and SH-SY5Y cells that do not have the homozygous deletion. To examine a role(s) of DFF45 in the regulation of apoptosis in response to CDDP, we have established stably DFF45-expressing NB-C201 cell clones (DFF45-1 and DFF45-3) and a control cell clone (NB-C201-C) using a retrovirus-mediated gene transfer. In contrast to NB-C201-C cells, DFF45-3 cells displayed apoptotic nuclear fragmentation in response to CDDP. Although CDDP-induced proteolytic cleavage of procaspase-3 and DFF45 in DFF45-3 cells, we could not detect a typical apoptotic DNA fragmentation. Additionally, deletion analysis revealed that C-terminal region of DFF45 is required for inducing nuclear fragmentation. Unexpectedly, (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays demonstrated that DFF45 has undetectable effect on CDDP sensitivity of NB-C201 cells. Taken together, our present results suggest that DFF45/DFF40 system may be sufficient for CDDP-induced nuclear fragmentation but not DNA cleavage.
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PMID:DFF45/ICAD restores cisplatin-induced nuclear fragmentation but not DNA cleavage in DFF45-deficient neuroblastoma cells. 1735 5

The potent antiapoptotic molecule Bcl-2 is markedly up-regulated in a majority of cancers, including neuroblastoma. Genistein is an isoflavone with antitumor properties. The present study sought to elucidate the molecular mechanism of genistein-induced apoptosis and also to examine the effect of genistein in increasing apoptosis during Bcl-2 knockdown in human malignant neuroblastoma SK-N-DZ cells. The cells were transfected with Bcl-2 siRNA plasmid vector, treated with 10 microM genistein, or the combination, and subjected to TUNEL staining and FACS analysis. Semiquantitative and real-time RT-PCR experiments were performed for examining expression of Fas ligand (FasL), tumor necrosis factor-alpha (TNF-alpha), Fas-associated death domain (FADD), and TNFR-1-associated death domain (TRADD). The cell lysates were analyzed by Western blotting for levels of molecules involved in both receptor- and mitochondria-mediated apoptotic pathways. Treatment with the combination of Bcl-2 siRNA and genistein resulted in more than 80% inhibition of cell proliferation. TUNEL staining and FACS analysis demonstrated apoptosis in 70% of cells after treatment with the combination of both agents. Apoptosis was associated with increases in Bax:Bcl-2 ratio, mitochondrial release of cytochrome c, and activation of caspases through the mitochondria-mediated apoptotic pathway. Genistein triggered the receptor-mediated apoptotic pathway through upregulation of TNF-alpha, FasL, TRADD, and FADD and activation of caspase-8. Combination of Bcl-2 siRNA and genistein triggered a marked increase in cleavage of DFF45 and PARP that resulted in enhanced apoptosis. Our study demonstrates that Bcl-2 knockdown during genistein treatment effectively induced apoptosis in neuroblastoma cells. Therefore, this strategy could serve as a potential therapeutic regimen to inhibit the growth of human malignant neuroblastoma.
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PMID:Genistein induces receptor and mitochondrial pathways and increases apoptosis during BCL-2 knockdown in human malignant neuroblastoma SK-N-DZ cells. 1981 66

Apoptotic cell death is characterized by nuclear fragmentation and oligonucleosomal DNA degradation, mediated by the caspase-dependent specific activation of DFF40/CAD endonuclease. Here, we describe how, upon apoptotic stimuli, SK-N-AS human neuroblastoma-derived cells show apoptotic nuclear morphology without displaying concomitant internucleosomal DNA fragmentation. Cytotoxicity afforded after staurosporine treatment is comparable with that obtained in SH-SY5Y cells, which exhibit a complete apoptotic phenotype. SK-N-AS cell death is a caspase-dependent process that can be impaired by the pan-caspase inhibitor q-VD-OPh. The endogenous inhibitor of DFF40/CAD, ICAD, is correctly processed, and dff40/cad cDNA sequence does not reveal mutations altering its amino acid composition. Biochemical approaches show that both SH-SY5Y and SK-N-AS resting cells express comparable levels of DFF40/CAD. However, the endonuclease is poorly expressed in the cytosolic fraction of healthy SK-N-AS cells. Despite this differential subcellular distribution of DFF40/CAD, we find no differences in the subcellular localization of both pro-caspase-3 and ICAD between the analyzed cell lines. After staurosporine treatment, the preferential processing of ICAD in the cytosolic fraction allows the translocation of DFF40/CAD from this fraction to a chromatin-enriched one. Therefore, the low levels of cytosolic DFF40/CAD detected in SK-N-AS cells determine the absence of DNA laddering after staurosporine treatment. In these cells DFF40/CAD cytosolic levels can be restored by the overexpression of their own endonuclease, which is sufficient to make them proficient at degrading their chromatin into oligonucleosome-size fragments after staurosporine treatment. Altogether, the cytosolic levels of DFF40/CAD are determinants in achieving a complete apoptotic phenotype, including oligonucleosomal DNA degradation.
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PMID:Apoptotic DNA degradation into oligonucleosomal fragments, but not apoptotic nuclear morphology, relies on a cytosolic pool of DFF40/CAD endonuclease. 2225 44


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