Recent years, the incidence and mortality of prostate cancer have increased dramatically in China. At earlier stages, most diagnosed prostate cancers are responsive to androgen depletion treatment, yet, nearly all patients will eventually progress to metastatic androgen-independent prostate cancer (AIPC), which still has no effective therapeutic method or drug to deal with. 11'-Deoxyverticillin A (C42) belongs to the family of epipolythiodioxopiperazines (ETPs), an interesting class of fungal toxins that inhibit farnesyl transferase. Compounds holding such a property have been explored as putative anticancer agents. In this study, using PC3M cells, an AIPC cell line, we investigated the effect of the compound on apoptosis and explored the underlying mechanism. It revealed that C42 markedly enhanced the activity of caspase-3/7 and increased the accumulation of the cleaved PARP, all of which are the markers of apoptosis. It also revealed that C42 either decreased cell viability or inhibited the growth of PC3M cells. Moreover, we observed that the loss of cell viability and cell growth inhibition induced by C42 were both time- and dosage dependent. Taken together, we indicated that C42 can induce caspase-dependent apoptosis in AIPC cells, and the results presented here will broaden our knowledge about the molecular mechanisms by which C42 exerts its anticancer activity, and future work in this direction may provide valuable information in the development of these compounds into effective cancer therapeutic strategies against androgen-independent prostate cancer.
Apoptosis ; drug effects ; Caspase 3 ; metabolism ; Caspase 7 ; metabolism ; Cell Line, Tumor ; Disulfides ; pharmacology ; Farnesyltranstransferase ; antagonists & inhibitors ; Humans ; Male ; Mycotoxins ; pharmacology ; Piperazines ; pharmacology ; Prostatic Neoplasms ; pathology

OBJECTIVETo explore the antagonizing effect of celecoxib against the cytotoxicity of carboplatin in human esophageal cancer cells.

METHODSThe cell viability of cisplatin-resistant cell line EC109/CDDP and its parental cell line EC109 exposed to carboplatin alone or carboplatin plus celecoxib was determined by MTT assay. The expression of CTR1, caspase-3 activation and PARP cleavage in the exposed cells were examined by Western blotting. Caspase-3 activity and cell apoptosis after the exposure were detected with Caspase-3/7 assay and flow cytometry, respectively. The effect of celecoxib on carboplatin accumulation in the cells was measured using inductively coupled plasma mass spectrometry (ICP-MS).

RESULTSCelecoxib treatment significantly increased the IC50 of carboplatin, suppressed carboplatin-induced caspase-3 and PARP cleavage and caspase-3 activity in EC109 and EC109/CDDP cells. Celecoxib also inhibited carboplatin-induced apoptosis and suppressed intracellular carboplatin accumulation in both cell lines. A combined exposure to celecoxib and carboplatin did not cause significant changes in the protein expression of CTR1.

CONCLUSIONCelecoxib antagonizes the cytotoxic effect of carboplatin and inhibits carboplatin-induced apoptosis in human esophageal cancer cells by reducing intracellular carboplatin accumulation.

Apoptosis ; Blotting, Western ; Carboplatin ; antagonists & inhibitors ; Caspase 3 ; metabolism ; Celecoxib ; Cell Line, Tumor ; drug effects ; Cell Survival ; Drug Interactions ; Esophageal Neoplasms ; metabolism ; pathology ; Humans ; Pyrazoles ; pharmacology ; Sulfonamides ; pharmacology

Roscovitine is a specific inhibitor of cyclin-dependent kinases (cdks) cdc2/cyclin B, cdk2/cyclin A, cdk2/cyclin E and cdk5/p35. The studies on the enzyme inhibitory properties and cellular effects of roscovitine revealed that it arrests cells in G(2)/M and G(1)/S phase, inhibits the proliferation of mammalian cells and induces cell death. However, the characteristics of cell death and exact mechanism by which this cdk inhibitor kills transformed cells are unknown. We previously investigated that the roscovitine induces apoptotic death of mitotic PC12 cells. The present study was to identify whether the roscovitine-induced death is related with the specific elements of caspases in pathway of apoptosis. The morphological data of caspase-3 immunofluorocytochemistry double staining with hoechst 33342 indicated that apoptotic nuclei were identified as nuclei with chromatin condensation and nuclear fragmentation, and that caspase-3 active p17 subunit co-existed in PC12 cells treated with roscovitine 50 micromol/L for 4 h. The number of the caspase-3 positive cells increased significantly to about 42%, as compared with the normal control (P<0.001). The data of MTT assay showed that the number of viable cells treated by roscovitine (50 micromol/L) alone for 12 h was 29.03%, of the untreated controls. Both a broad-spectrum caspase inhibitor Z-VAD-FMK (50 mumol/L) and a specific caspase-3 inhibitor Z-DEVD-FMK (100 micromol/L) increased viable PC12 cells to 45.16%, (Z-DEVD-FMK) and 58.06%, (Z-VAD-FMK), respectively, in the presence of roscovitine. Non-erythroid a-spectrin is a cytoskeleted protein that is a substrate of caspase-3 cysteine proteases. To confirm the activity of caspase-3 that produced in roscovitine (50 micromol/L for 12 h)-induced PC12 cell death, activated caspase-3 specific 120 kDa spectrin breakdown products (SBDP) were detected by Western bloting using the mouse anti-non-erythroid a-spectrin monoclonal antibody. The mean relative density of bands corresponding to caspase-3 specific SBDP levels were significantly increased in the cytosolic fractions treated with roscovitine, as compared to the normal control (P<0.001). These results indicate that caspase signals, especially caspase-3 signal are necessary for the progression of proliferating PC12 cell apoptotic death evoked by roscovintine.
Animals ; Apoptosis ; drug effects ; physiology ; Caspase 3 ; physiology ; Cyclin-Dependent Kinases ; antagonists & inhibitors ; PC12 Cells ; Protein Kinase Inhibitors ; pharmacology ; Purines ; pharmacology ; Rats

OBJECTIVETo investigate the expression changes and effects of hypoxia inducible factor-1α (HIF-1α) on non-lethal high temperature induced thermotolerance and its role on thermotolerance protection.

METHODSH9c2 cardiomyocytes were cultured and pretreated with the HIF-1α inhibitor YC-1, the cells were then subjected to normal temperature (37 °C), thermotolerance induction (40 °C, 3 h), or hyperthermia (43 °C, 2 h). The cells were divided into 8 groups (n = 3 each): normal temperature control group; thermotolerance group; thermotolerance/hyperthermia group; hyperthermia group; DMSO+normal temperature group; YC-1+thermotolerance group; YC-1+thermotolerance/hyperthermia group; YC-1+hyperthermia group. Cell apoptotic rate was assessed by flow cytometry. Western blot was used to detect the expression of HIF-1α and caspase-3.

RESULTSFlow cytometry results showed that apoptosis rate was similar between control group and thermotolerance group, between DMSO+normal temperature group and YC-1+thermotolerance group, between YC-1+thermotolerance/hyperthermia group and YC-1+hyperthermia group, but was significantly higher in hyperthermia group [(17.35 ± 1.07)%] than in control group [(7.52 ± 1.55)%, P < 0.01] which was partly reduced in thermotolerance/hyperthermia group [(12.58 ± 1.97)%, P < 0.01 vs. thermotolerance group]. Cell apoptosis rate of YC-1+thermotolerance/hyperthermia group (23.75 ± 1.92)% was significantly higher than that of thermotolerance/hyperthermia group [(12.58 ± 1.97)%, P < 0.01], and in YC-1+hyperthermia group [(24.89 ± 1.83)%] than in hyperthermia group [(17.35 ± 1.07)%, P < 0.01]. HIF-1α expression was obviously upregulated in thermotolerance cells compared with control cells, in thermotolerance/hyperthermia cells than in hyperthermia cells, in YC-1+thermotolerance group, YC-1+thermotolerance/hyperthermia group and YC-1+hyperthermia group than in DMSO group (all P < 0.05). Caspase-3 expression was similar between control group and thermotolerance group, but was significantly lower in thermotolerance/hyperthermia group than in hyperthermia group (P < 0.05), significantly higher in YC-1+thermotolerance group, YC-1+thermotolerance/hyperthermia group and YC-1+hyperthermia group than in DMSO group (all P < 0.05) and significantly higher in YC-1+thermotolerance/hyperthermia group than in thermotolerance/hyperthermia group (P < 0.01) and in YC-1+hyperthermia group than in hyperthermia group (P < 0.01).

CONCLUSIONNon-lethal high temperature induced thermotolerance can reduce heat stress-induced cardiomyocytes apoptosis rate via upregulating the expression of HIF-1α and inhibiting caspase-3 signalling pathways.

Animals ; Apoptosis ; Caspase 3 ; metabolism ; Cells, Cultured ; Hot Temperature ; Hypoxia-Inducible Factor 1, alpha Subunit ; antagonists & inhibitors ; physiology ; Myocytes, Cardiac ; metabolism ; pathology ; Rats ; Signal Transduction

OBJECTIVETo compare the sensitivity of different hepatocellular carcinoma (HCC) cell lines (HepG2, QGY7701, HepG2.2.15) and the normal liver cell line L02 to 5-aza-dC, an DNA methyltransferase inhibitor, and to explore the relationship between global DNA methylation level and the sensitivity to 5-aza-dC.

METHODSHepG2, QGY7701, HepG2.2.15 and L02 cells were treated with 5-aza-dC at different concentration, cell proliferation was measured by MTT method, cell apoptosis was detected by measuring caspase 3 activity and cellular DNA fragmentation ELISA.

RESULTSCompared to HepG2 and QGY7701 cells, HepG2.2.15 were less sensitive to the treatment of 5-aza-dC; the normal liver cell line L02 was less sensitive to 5-aza-dC than the HCC cell lines.

CONCLUSIONSThe sensitivity to 5-aza-dC of HCC cell lines and normal liver cells is not correlated with the global DNA methylation level.

Azacitidine ; analogs & derivatives ; pharmacology ; Carcinoma, Hepatocellular ; metabolism ; Caspase 3 ; metabolism ; DNA Methylation ; drug effects ; DNA Modification Methylases ; antagonists & inhibitors ; Hep G2 Cells ; Humans

Cathepisn D plays a key role in early process of apoptosis before mitochondrion damage and caspases activations, and also involves in Alzheimer's disease (AD). Glycosaminoglycans (GAGs) have been suggested to inhibit the progress of apoptosis. Fucoidan, a nature GAGs mimetic, is shown as a potential candidate for neuroregressive disease. Here we reported PC12 cells response to oxidative stress with clear cathepsin D release, followed by caspase-3 activation. We found that fucoidan treatment can alleviate cathepsin D and caspase-3 activation, and improve cell survival. Furthermore, for the first time, fucoidan was shown to directly inhibit human liver cathepsin D by a dose-dependent way. These results support that cathepsin D involves in early apoptosis, suggest that fucoidan can decrease apoptosis at lysosome-cathepsin D level, which opens a new therapeutic approach to AD.
Alzheimer Disease ; drug therapy ; metabolism ; Animals ; Apoptosis ; drug effects ; Caspase 3 ; metabolism ; Caspase Inhibitors ; Cathepsin D ; antagonists & inhibitors ; metabolism ; Cell Line, Tumor ; Cell Survival ; drug effects ; Humans ; Hydrogen Peroxide ; metabolism ; Oxidative Stress ; drug effects ; PC12 Cells ; Polysaccharides ; pharmacology ; Rats

Our experiments aimed to clarify the mechanism by which host cell apoptosis is inhibited by infection with the intracellular protozoan parasite, Toxoplasma gondii (T. gondii). Mouse spleen cells were cultured in 6-well plates with RPMI 1640/ 10% FBS at 37(i)E, in a 5% CO2 atmosphere. Apoptosis of spleen cells was induced by actinomycin-D (AD) treatment for 1 h prior to infection with T. gondii. A variety of assays were used to assess the progression of apoptosis: DNA size analysis on agarose gel electrophoresis, flow cytometry with annexin V/PI staining, and analysis of expression levels of Bcl-2 family and NF-kappaB mRNA and proteins by RT-PCR, Western blotting, and EMSA. Additionally, transmission electron microscopy (TEM) was performed to observe changes in cell morphology. Fragmentation of DNA was inhibited in spleen cells treated with AD and T. gondii 5 h and 18 h post infection, respectively, and flow cytometry studies showed a decreased apoptotic rates in AD and T. gondii treated spleen cells. We observed decreased expression of Bax mRNA and protein, while levels of Bcl-2 mRNA remained constant in spleen cells treated with AD and T. gondii. Caspase 3 and PARP were inactivated in cells treated with AD and T. gondii, and increased levels of cleaved caspase 8 were also observed. Analysis of EMSA and Western blot data suggests that activation of transcription factor NF-kappaB may be involved in the blockade of apoptosis by T. gondii. TEM analysis showed nuclear fragmentation and chromatin condensation occurring in spleen cells treated with AD; however, such apoptosis- associated morphological changes were not observed in cells treated with both AD and T. gondii tachyzoites. Together, these data show that T. gondii infection inhibits AD induced apoptosis via caspase inactivation and NF-kappaB activation in mouse spleen cells.
bcl-2-Associated X Protein/metabolism ; Toxoplasma/*physiology ; RNA, Messenger/metabolism ; Poly(ADP-ribose) Polymerases/antagonists & inhibitors ; NF-kappa B/*metabolism ; Mice ; Gene Expression Regulation ; Flow Cytometry ; DNA Fragmentation ; Cells, Cultured ; Caspase 3/*antagonists & inhibitors ; Apoptosis/*physiology ; Animals

Our experiments aimed to clarify the mechanism by which host cell apoptosis is inhibited by infection with the intracellular protozoan parasite, Toxoplasma gondii (T. gondii). Mouse spleen cells were cultured in 6-well plates with RPMI 1640/ 10% FBS at 37(i)E, in a 5% CO2 atmosphere. Apoptosis of spleen cells was induced by actinomycin-D (AD) treatment for 1 h prior to infection with T. gondii. A variety of assays were used to assess the progression of apoptosis: DNA size analysis on agarose gel electrophoresis, flow cytometry with annexin V/PI staining, and analysis of expression levels of Bcl-2 family and NF-kappaB mRNA and proteins by RT-PCR, Western blotting, and EMSA. Additionally, transmission electron microscopy (TEM) was performed to observe changes in cell morphology. Fragmentation of DNA was inhibited in spleen cells treated with AD and T. gondii 5 h and 18 h post infection, respectively, and flow cytometry studies showed a decreased apoptotic rates in AD and T. gondii treated spleen cells. We observed decreased expression of Bax mRNA and protein, while levels of Bcl-2 mRNA remained constant in spleen cells treated with AD and T. gondii. Caspase 3 and PARP were inactivated in cells treated with AD and T. gondii, and increased levels of cleaved caspase 8 were also observed. Analysis of EMSA and Western blot data suggests that activation of transcription factor NF-kappaB may be involved in the blockade of apoptosis by T. gondii. TEM analysis showed nuclear fragmentation and chromatin condensation occurring in spleen cells treated with AD; however, such apoptosis- associated morphological changes were not observed in cells treated with both AD and T. gondii tachyzoites. Together, these data show that T. gondii infection inhibits AD induced apoptosis via caspase inactivation and NF-kappaB activation in mouse spleen cells.
bcl-2-Associated X Protein/metabolism ; Toxoplasma/*physiology ; RNA, Messenger/metabolism ; Poly(ADP-ribose) Polymerases/antagonists & inhibitors ; NF-kappa B/*metabolism ; Mice ; Gene Expression Regulation ; Flow Cytometry ; DNA Fragmentation ; Cells, Cultured ; Caspase 3/*antagonists & inhibitors ; Apoptosis/*physiology ; Animals

ER-α36 is a novel 36-kDa variant of ER-α. A large of evidence demonstrated that ER-α36 responded to membrane-initiated estrogen signaling pathways which were involved in the physiological and pathological process in many kinds of cells. In this study, knock-down of ER-α36 expression in pheochromocytoma (PC12) cells (named as PC12-36L cells) by using the shRNA method was used to evaluate the relationship between ER-α36 and Akt in neurons under glucose deprivation. The effect of ER-α36 on outgrowth of PC12 cells, as well as the neuroprotective effect of ER-α36 on injured PC12 cells exposed to glucose deprivation was observed by using MTT assay, Western blot and Annexin V/PI staining et al. The results showed that, (1) Glucose deprivation induced by MEM treatment for 6 h reduced survival rate and increased apoptotic rate in PC12 cells significantly compared to control group (P < 0.01); and it produced a decrease in the expression of Glut-4 protein (P < 0.01); (2) The expression level of ER-α36 was decreased significantly at 3 h of glucose deprivation, and then increased, while phosphorylation of Akt participated in the glucose deprivation was increased at first and then reduced; LY294002 (PI3K inhibitor) contributed to decreased expression of ER-α36, and suppressed the activation of Akt; (3) The rate of apoptosis was significantly increased in PC12-36L cells after glucose deprivation compared with that in wild type PC12 cells (P < 0.01). Furthermore, phosphorylation of Akt was decreased and Caspase-3 was increased by glucose deprivation in PC12-36L cells compared with those in wild type PC12 cells. The study reveals that phosphorylation of Akt is associated with ER-α36 in PC12 cells exposed to glucose deprivation, and both are involved in the regulation of stress responses.
Animals ; Apoptosis ; Caspase 3 ; metabolism ; Chromones ; pharmacology ; Culture Media ; chemistry ; Estrogen Receptor alpha ; metabolism ; Glucose ; chemistry ; Morpholines ; pharmacology ; PC12 Cells ; Phosphatidylinositol 3-Kinases ; antagonists & inhibitors ; Phosphorylation ; Proto-Oncogene Proteins c-akt ; metabolism ; Rats ; Signal Transduction

The present study aimed to investigate the effects of humanin (HN) on primary cortical neuronal apoptosis induced by Abeta31-35, and explore the potential mechanisms. Cultured cortical neurons were pretreated with different concentrations of HN (5, 10, 20 micromol/L) for different time period (0, 8 and 16 h) respectively, and then exposed to Abeta31-35 (25 micromol/L) for additional 24 h and the neuronal apoptosis was examined by morphological analysis, flow cytometric assays and TUNEL staining. Caspase activities were measured using a spectrophotometer. Bax expression was measured by Western blot. The results were as follows. (1) Pretreatment with HN (20 micromol/L) for 16 h significantly prevented Abeta31-35-induced apoptosis in cortical neurons; (2) HN significantly decreased Abeta31-35-induced elevation of caspase-3 and -9 activities; (3) HN suppressed Abeta31-35-induced translocation of Bax from the cytosol to mitochondria, but had no effect on overall Bax expression. In conclusions, HN attenuated Abeta31-35-induced cortical neuronal apoptosis by blocking intrinsic caspase-dependent apoptotic pathways.
Amyloid beta-Peptides ; antagonists & inhibitors ; toxicity ; Animals ; Animals, Newborn ; Apoptosis ; drug effects ; Caspase 3 ; metabolism ; Caspase 9 ; metabolism ; Cells, Cultured ; Cerebral Cortex ; cytology ; pathology ; Intracellular Signaling Peptides and Proteins ; pharmacology ; Neurons ; cytology ; pathology ; Neuroprotective Agents ; pharmacology ; Peptide Fragments ; antagonists & inhibitors ; toxicity ; Rats ; Rats, Sprague-Dawley