Suppression of apoptosis is one of the hallmarks of carcinogenesis. Tumor cells endure apoptotic pressure by overexpressing several antiapoptotic proteins, and FLICE inhibitory protein (FLIP) is one of the important antiapoptotic proteins that have been shown to be overexpressed in various primary tumor cells. FLIP has two death-effector domains in tandem, mimicking the prodomain of procaspase-8. It is recruited to Fadd in death-inducing signaling complex, thereby preventing the activation of procaspase-8. To date, three isoforms of human cytosolic FLIP (c-FLIP) and six viral homologs (v-FLIP) have been identified. Recently, the crystal structure of v-FLIP MC159 was determined for the first time as an atomic-detail FLIP structure, which revealed that two death effector domains are packed tightly against each other mainly through conserved hydrophobic interactions. The overexpression of c-FLIP in tumor cells has been shown to be the determinant of the tumor's resistance to death ligands such as FasL and TRAIL. It has also been shown that the down-regulation of c-FLIP results in sensitizing resistant tumor cells. Therefore, the agents directly targeting c-FLIP at mRNA and protein levels are expected to be developed in near future and tested for the potential as a new class of anti-cancer drugs.
Apoptosis ; CASP8 and FADD-Like Apoptosis Regulating Protein/antagonists & inhibitors/chemistry/*metabolism ; Caspases/antagonists & inhibitors/metabolism ; Humans ; Neoplasms/*metabolism/pathology/*therapy ; Signal Transduction

OBJECTIVETo investigate the effects and underlying mechanism of notoginsenoside R1 on amyloid-β (1-42) (Aβ(1-42)) induced mitochondrial apoptotic death in SH-SY5Y cells.

METHODCell viability was assayed by MTT, apoptotic rates were analyzed with PI/Annexin V flow cytometry, Bax and Bcl-2 expression were detected with Western blotting, enzymatic activity of caspase-3, caspase-8 and caspase-9 were measured by ELISA assay.

RESULTThe 6.25-100 nmol x L(-1) of notoginsenoside R1 attenuate Aβ(1-42) induced apoptotic death of SH-SY5Y in dose dependent manner. The ratio of Bcl-2/Bax was elevated in SH-SY5Y with notoginsenoside R1 treatment. Caspase-3 and caspase-9 were activated with notoginsenoside R1 treatment while caspase-8 was not affected.

CONCLUSIONNotoginsenoside R1 could protect SH-SY5Y cells from Aβ(1-42) induced apoptosis via mitochondria related apoptotic pathway.

Amyloid beta-Peptides ; antagonists & inhibitors ; Apoptosis ; drug effects ; Caspases ; metabolism ; Cell Line, Tumor ; Cell Survival ; drug effects ; Cytoprotection ; Ginsenosides ; pharmacology ; Humans ; Mitochondria ; drug effects ; Peptide Fragments ; antagonists & inhibitors

Primary neuronal culture is a powerful tool to study neuronal development, aging, and degeneration. However, cultured neurons show signs of cell death after 2 or 3 weeks. Although the mechanism underlying this phenomenon has not been elucidated, several preventive methods have been identified. Here we show that the neuronal loss in primary cortical culture involves calpain activation and subsequent neuronal cell death. Neuronal loss during cultivation showed destruction of neurites and synapses, and a decrease in neuron numbers. micro-Calpain and micro-calpain were initially activated and accumulated by increased RNA expression. This neuronal death exhibited neurodegenerative features, such as conversion of p35 to p25, which is important in the developmental process and in the pathogenesis of Alzheimer's disease. But, postnatal and aged rat cortex did not show calpain activation and prolonged processing of p35 to p25, in contrast to the long-term culture of cortical neurons. In addition, the inhibition of calpains by ALLM or ALLN blocked the conversion of p35 to p25, indicating that the calpain activity is essential for the neurodegenerative features of cell death. Taken together, this study shows that the neuronal loss in primary cortical cultures involves neurodegeneration-like cell death through the activation of calpains and the subsequent processing of p35 to p25, but not developmental apoptosis or aging. Our results suggest that the long term primary culture of cortical neurons represent a valuable model of neurodegeneration, such as Alzheimer's disease.
Transcription, Genetic/genetics ; Time Factors ; Rats ; Phosphotransferases/*metabolism ; Neurons/*cytology/*metabolism ; Cells, Cultured ; Cell Shape ; Caspases/antagonists & inhibitors/metabolism ; Calpain/antagonists & inhibitors/genetics/*metabolism ; *Apoptosis ; Animals

OBJECTIVETo evaluate antisense technology for human telomerase inhibition in the treatment of endometrial cancer.

METHODSAn antisense oligodeoxynucleotides (AODN) directed against the human telomerase transcriptase (hTERT), designed and synthesized to serve as a telomerase inhibitor, was transfected into endometrial carcinoma cell line HEC-1A by lipofectin. Reverse transcription-polymerase chain reaction (RT-PCR) and Western blot were used to test the expression of hTERT mRNA and hTERT protein before and after transfection. Telomerase activity was tested by telomeric repeat amplification protocol. The proliferation and growth of HEC-1A were also studied by methyl thiazolyl tetrazolium and cell growth curve before and after transfection.

RESULTSAODN could down-regulate the expression of hTERT mRNA and protein, inhibiting telomerase activity and proliferation of endometrial cancer cell line in a dose- and period-dependent manner.

CONCLUSIONAntisense oligodeoxynucleotides of human telomerase transcriptase definitely inhibits the proliferation of endometrial cancer cell line. Telomerase inhibitor may thus become a new gene therapeutic agent for endometrial carcinoma.

Caspases ; metabolism ; Cell Line, Tumor ; Cell Proliferation ; Endometrial Neoplasms ; pathology ; therapy ; Female ; Genetic Therapy ; Humans ; Oligonucleotides, Antisense ; genetics ; RNA, Messenger ; analysis ; Telomerase ; antagonists & inhibitors ; genetics

BACKGROUND/AIMS: Prostaglandin (PG) A2 has been reported to inhibit the growth of hepatocellular carcinoma cells via activation of apoptosis, although the molecular mechanisms involved have not been clarified, yet. To investigate the mechanism of the PGA2-induced apoptosis, we analyzed the activation of caspases during the apoptosis of hepatoma cell lines. METHODS: Induction of apoptosis by PGA2 in hepatoma cell lines, Hep 3B and Hep G2, was assessed by DAPI staining of nuclei and agarose gel electrophoresis of genomic DNA. The involvement of caspases was analyzed by immunoblot analysis of poly ADP-ribose polymerase (PARP) and by checking the effect of caspase inhibitors on PGA2-induced apoptosis. RESULTS: PGA2 inhibited the growth of Hep 3B and Hep G2 cells, accompanying nuclear condensation and fragmentation, and genomic DNA laddering, which are the hallmarks of apoptosis. The PARP was not cleaved during the apoptosis of Hep 3B and Hep G2 cells and caspase inhibitors such as z-VAD-Fmk and z-DEVD-Fmk exerted no effect on the PGA2-induced apoptosis. CONCLUSIONS: These results suggest that PGA2 induces apoptosis in Hep 3B and Hep G2 cells via caspase-independent pathway.
Apoptosis/*drug effects ; Carcinoma, Hepatocellular/*pathology ; Caspases/antagonists & inhibitors/*metabolism ; Cell Line, Tumor ; Cell Proliferation/drug effects ; Enzyme Activation ; Humans ; Liver Neoplasms/*pathology ; Prostaglandins A/*pharmacology ; Research Support, Non-U.S. Gov't ; Tumor Cells, Cultured

Norcantharidin (NCTD) is the demethylated form of cantharidin, which is the active substance of mylabris. To examine the pathway of NCTD-induced A375-S2 cell death, 3-(4, 5-dimethylthiazol-2-yl)-2, 5-dipheyltetrazolium bromide (MTT) assay, photomicroscopical observation, DNA agarose gel electrophoresis, caspase activity assay and Western blot analysis were carried out. A375-S2 cells treated with NCTD exhibited several typical characteristics of apoptosis. The inhibitory effect of NCTD on human melanoma, A375-S2 cells, was partially reversed by the inhibitors of pan-caspase, caspase-3 and caspase-9. The activities of caspase-3 and -9 were significantly increased after treatment with NCTD at different time. The expression of inhibitor of caspase-activated DNase was decreased in a time-dependent manner, simultaneously, the ratio of Bcl-2/Bax or Bcl-xL/Bax was decreased and the expression ratio of proteins could be reversed by caspase-3 inhibitor. The expression of cytochrome c in cytosol was increased after NCTD treatment and caspase- 3 inhibitor had no significant effect on the up-regulation of cytochrom c. These results suggest that NCTD induced A375-S2 cell apoptosis and the activation of caspase and mitochondrial pathway were involved in the process of NCTD-induced A375-S2 cell apoptosis.
Animals ; Apoptosis/*physiology ; Bicyclo Compounds, Heterocyclic/chemistry/metabolism/*pharmacology ; Caspases/antagonists & inhibitors/*metabolism ; Cell Line, Tumor/*drug effects ; Cell Shape ; DNA Fragmentation ; Enzyme Activation ; Humans ; Mitochondria/*metabolism ; Molecular Structure ; Proto-Oncogene Proteins c-bcl-2/metabolism ; Signal Transduction/*physiology

OBJECTIVETo evaluate the effects of Carvedilol on cardiopulmonary bypass (CPB)-induced myocardiocyte apoptosis and its effects on regulation of Fas, FasL expression, caspase-3 activity and oxidative stress in the left ventricle (LV) in this setting.

METHODSTen adult dogs undergoing conventional hypothermic CPB were randomly divided into control and Carvedilol treated groups (n = 5, respectively). Dogs in Carvedilol treated group received a bolus of Carvedilol (1 mg/kg) intravenously and a maintenance dosage of Carvedilol (3 micro g.min(-1).kg(-1)) for 3 hours after the reperfusion of the heart. Dogs in control group received no Carvediolol. LV samples were obtained before, during and 3 hours after CPB. In situ nick end-labeling (TUNEL) technique was used to detect the apoptotic cells. The expressions of Fas and FasL were detected immunohistochemically and quantified by fluorescence activated cell sorting (FACS). The activity of caspase-3 enzyme and malondialdehyde (MDA) level were measured by cleavage of Z-DEVD-AMC substrate and thiobarbituric acid reactive substance (TBARS) method, respectively.

RESULTSBefore and during CPB, all the parameters were not significantly different intra- or between groups (P > 0.05). After CPB, these parameters in both groups were significantly elevated compared with those of before and during CPB (P < 0.028, respectively). However, the number of apoptotic cells in Carvedilol treated group was significantly decreased compared with that of the control group (P < 0.021). The expressions of Fas and FasL were significantly downregulated by Carvedilol (P < 0.001 and 0.003, respectively). The caspase-3 activity and the content of MDA in the Carvedilol treated group was also significantly reduced (P < 0.026 and 0.005, respectively).

CONCLUSIONSCarvedilol significantly reduces CPB-induced cardiomyocyte apoptosis in dog hearts and the reduction of cardiomyocyte apoptosis is associated with downregulation of Fas and FasL expression, inhibition of caspase-3 activity and oxidative stress in LV.

Adrenergic beta-Antagonists ; pharmacology ; Animals ; Apoptosis ; Carbazoles ; pharmacology ; Cardiopulmonary Bypass ; Caspase 3 ; Caspases ; metabolism ; Dogs ; Down-Regulation ; Fas Ligand Protein ; Female ; In Situ Nick-End Labeling ; Male ; Membrane Glycoproteins ; metabolism ; Myocytes, Cardiac ; cytology ; metabolism ; Propanolamines ; pharmacology ; Signal Transduction ; fas Receptor ; metabolism

OBJECTIVETo investigate the effect of aurora kinase inhibitor ENMD-2076 on human acute myelogenous leukemia (AML) cell lines.

METHODSAML THP-1 and Kasumi-1 cells were treated with ENMD-2076 for 24 h and 48 h,respectively. Cell growth was measured by MTT assay. Apoptosis was determined using Hoechst staining apoptosis detection kit. Activation of Caspase pathway and expression of apoptosis regulator proteins were detected by Western blot.

RESULTSENMD-2076 significantly induced growth arrest and apoptosis in THP-1 and Kasumi-1 cells. Enhanced apoptosis was observed in ENMD-2076 group evidenced by strong activation of Caspase-9,Caspase-3 and PARP. Furthermore,the ENMD-2076 treatment resulted in down-regulation of anti-apoptotic protein Mcl-1 expression. Also,up-regulated expression of pro-apoptotic protein Bak,Bad and Bax was detected after ENMD-2076 treatment.

CONCLUSIONENMD-2076 can kill effectively AML cells by inhibiting cell growth and inducing apoptosis,which is associated with activation of Caspase pathway and regulation of pro-apoptotic and anti-apoptotic proteins.

Apoptosis ; drug effects ; Apoptosis Regulatory Proteins ; metabolism ; Aurora Kinases ; Caspases ; metabolism ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Humans ; Leukemia, Myeloid, Acute ; metabolism ; pathology ; Protein-Serine-Threonine Kinases ; antagonists & inhibitors ; Pyrazoles ; pharmacology ; Pyrimidines ; pharmacology

FTY720, a synthetic sphingoid base analog, was examined as a new sphingosine kinase inhibitor, which converts endogenous sphingosine into its phosphate form. With 20 micrometer of FTY720, sphingosine accumulated in the LLC-PK1 cells in a time- and dose-dependent manner. The FTY720 treated cells showed a high concentration of fragmented DNA, a high caspase-3 like activity and TUNEL staining cells. It was also found that the sphingosine and sphinganine level increased in a time- and dose-dependent manner within 12 h after the FTY720 treatment. The sphingosine kinase activity was reduced by FTY720 as much as other sphingosine kinase inhibitors, N, N-dimethylsphingosine (DMS), dl-threo-dihydrosphingosine (DHS). The fragmented DNA content as a result of the 20 micrometer of FTY720 treatment and by 5 micrometer of the exogenously added BSA-sphingosine complex indicated typical apoptosis. Under similar conditions, the accumulated sphingosine concentration in all the cells was almost identical even though the sphingosine distribution inside the cells was somewhat different. These results indicate that the FTY720 induced apoptosis is associated with the inhibition of the sphingosine kinase activity and is strongly associated with the successive accumulation of sphingosine.
Animals ; Apoptosis/*physiology ; Caspases/biosynthesis ; Cell Line ; DNA Fragmentation ; Endothelial Cells/drug effects ; Enzyme Inhibitors/*pharmacology ; Kidney/cytology ; Phosphotransferases (Alcohol Group Acceptor)/*antagonists & inhibitors/physiology ; Propylene Glycols/*pharmacology ; Research Support, Non-U.S. Gov't ; Sphingosine/pharmacology/*physiology ; Swine ; Up-Regulation

OBJECTIVETo investigate the mechanism of U87 cell apoptosis induced by inhibiting miR-21 expression.

METHODSAntisense oligonucleotides of miR-21 were chemically synthesized and transfected into U87 cells. The apoptosis, proliferation, and invasion of the cells were evaluated. The relationship between miR-21 and PTEN or caspase was identified by bioinformatics and Western blot.

RESULTSInhibiting miR-21 expression led to U87 cell growth suppression, apoptosis induction, invasion reduction, caspase-3 activity elevation and caspase-9 activation, but did not affect PTEN and caspase-8 expression.

CONCLUSIONmiR-21 may function as an antiapoptotic miRNA in U87 cells. Inhibiting miR-21 expression could induce U87 cell apoptosis via caspase-9 and 3 activation, but not PTEN activation.

Animals ; Apoptosis ; drug effects ; genetics ; Caspases ; metabolism ; Cell Line, Tumor ; Cell Proliferation ; Enzyme Activation ; genetics ; Gene Expression Regulation, Neoplastic ; Glioma ; genetics ; pathology ; Humans ; MicroRNAs ; antagonists & inhibitors ; genetics ; Oligoribonucleotides, Antisense ; genetics ; pharmacology ; PTEN Phosphohydrolase ; metabolism ; Transfection